METHODS AND APPARATUS IN A NETWORK NODE OR BASE STATION

Technical Field

Examples of the present disclosure relate to methods and apparatus in a network node or base station.

Background

Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and/or is implied from the context in which it is used. All references to a/an/the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and/or where it is implicit that a step must follow or precede another step. Any feature of any of the embodiments disclosed herein may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Other objectives, features and advantages of the enclosed embodiments will be apparent from the following description.

Mobility in RRC CONNECTED in LTE and NR

An RRC_CONNECTED wireless device (or UE) in LTE (also called EUTRA) can be configured by the network to perform measurements and, upon triggering measurement reports, the network may send a handover command to the UE (e.g. in LTE an RRConnectionReconfiguration with a field called mobilityControllnfo and in New Radio, NR, or 5G an RRCRecon figuration with a reconfigurationWithSync field).

These reconfigurations are prepared by the target cell upon a request from the source node (e.g. over X2 interface in case of EUTRA-EPC or Xn interface in case of EUTRA-5GC or NR) and takes into account the existing RRC configuration the UE has with source cell (which are provided in the inter-node request). Among other parameters, that reconfiguration provided by the target cell contains all information the UE needs to access the target cell, e.g., random access configuration, a new C-RNTI assigned by the target cell and security parameters enabling the UE to calculate new security keys associated to the target cell so the UE can send a handover complete message on SRB1 (encrypted and integrity protected) based on new security keys upon accessing the target cell.

Figure 1 summarizes the flow signalling 100 between UE, source node (which in this example is a gNB) and target node (which in this example is also a gNB) during a handover procedure, which also involves an AMF and a UPF. Initially, user data is exchanged between UE and source gNB, and between source gNB and UPF(s). Steps 0-5 of Figure 1 are a handover preparation stage. In step 0 of Figure 1 , Mobility Control Information is provided by AMF to source gNB. In step 1 , measurement control and reports are exchanged between UE and source gNB. In step 2, the source gNB makes a handover (HO) decision. In step 3, source gNB sends a handover request to a target gNB. In step 4, target gNB performs admission control. In step 5, target gNB sends a HO request acknowledge to source gNB. Steps 6-8 are a handover execution stage. In step 6, Uu handover trigger information is exchanged between UE and source gNB. The UE detaches from the old cell and synchronises to the new cell. In step 7, source gNB sends SN status transfer to target gNB, and delivers buffered and in transit user data to target gNB. The source gNB may also forward user data to target gNB. The target gNB buffers user data from source gNB. In step 8, the UE synchronises to the new cell (target gNB) and completed RRC HO procedure. User data may then be exchanged between UE and target gNB. User data may be forwarded from target gNB to User Plane Function(s). Steps 9-12 are a handover completion stage. In step 9, target gNB sends a path switch request to AMF. In step 10, AMF and UPF(s) exchange path switch related 5G CN internal signalling and actual DL path switch is performed in UPF(s). User data may then be exchanged between target gNB and UPF(s). In step 1 1 , AMF returns a path switch request acknowledgment to the target gNB. In step 12, target gNB sends a UE context release to source gNB.

Both in LTE and NR, some principles exist for handovers (or in more general terms, mobility in RRC_CONNECTED):

Mobility in RRC_CONNECTED is network-based as the network has best info regarding current situation such as load conditions, resources in different nodes, available frequencies, etc. Network can also take into account the situation of many UEs in the network, for a resource allocation perspective.

Network prepares a target cell before the UE accesses that cell. Source provides UE with the RRC configuration to be used in the target cell, including SRB1 configuration to send HO complete. UE is provided by target with a target C-RNTI i.e. target identifies UE from MSG.3 on MAC level for the HO complete message. Hence, there is no context fetching, unless a failure occurs.

To speed up the handover, network provides needed information on how to access the target e.g. RACH configuration, so the UE does not have to acquire system information (SI) prior to the handover.

UE may be provided with CFRA resources, i.e. so that the target identifies the UE from the preamble (MSG.1). The principle behind here is that the procedure can be optimized with dedicated resources. In conditional handover (CHO) this may be difficult as there is uncertainty about the final target but also the timing.

Security is prepared before the UE accesses the target cell i.e. Keys must be refreshed before sending RRC Connection Reconfiguration Complete message, based on new keys and encrypted and integrity protected so UE can be verified in target cell.

Both full and delta reconfiguration are supported so that the HO command can be minimized.

Mobility robustness Work Item in Rel-16 for LTE and NR and Conditional HO

Two new work items for mobility enhancements in LTE and NR have started in 3GPP in release 16. The main objectives of the work items are to improve the robustness at handover and to decrease the interruption time at handover.

One problem related to robustness at handover is that the HO Command (e.g. RRCConnectionReconfiguration with mobilityControllnfo and RRCReconfiguration with a reconfigurationWithSync field) is normally sent when the radio conditions for the UE are already quite bad. That may lead to that the HO Command may not reach the UE in time if the message is segmented or there are retransmissions.

In LTE and NR, different solutions to increase mobility robustness have been discussed in the past. One solution discussed in NR is called“conditional handover” (CHO) or “early handover command”. In order to avoid the undesired dependence on the serving radio link upon the time (and radio conditions) where the UE should execute the handover, the possibility to provide RRC signaling for the handover to the UE earlier should be provided. To achieve this, it should be possible to associate the handover (HO) command with a condition e.g. based on radio conditions possibly similar to the ones associated to an A3 event, where a given neighbour becomes X db better than target. As soon as the condition is fulfilled, the UE executes the handover in accordance with the provided handover command.

Such a condition could e.g. be that the quality of the target cell or beam becomes X dB stronger than the serving cell. The threshold Y used in a preceding measurement reporting event should then be chosen lower than the one in the handover execution condition. This allows the serving cell to prepare the handover upon reception of an early measurement report and to provide the HO command (e.g. RRCConnectionReconfiguration with mobilityControllnfo (LTE) or RRCReconfiguration with a reconfigurationWithSync (NR)) at a time when the radio link between the source cell and the UE is still stable. The execution of the handover is done at a later point in time (and threshold) which is considered optimal for the handover execution.

Figure 2 depicts an example 200 of a conditional handover procedure with a UE, serving cell (in this case illustrated as serving gNB) and a target cell (in this case a target gNB). In practice there may often be many cells or beams that the UE reported as possible candidates based on its preceding RRM measurements. The network should then have the freedom to issue conditional handover commands for several of those candidates. The RRCConnectionReconfiguration for each of those candidates may differ e.g. in terms of the HO execution condition (RS to measure and threshold to exceed) as well as in terms of the RA preamble to be sent when a condition is met. In Figure 2, serving gNB may exchange user plane (UP) data with the UE. In step 1 , the UE sends a measurement report with“low” threshold to serving gNB. The serving gNB makes a HO decision based on this early report. In step 2, the serving gNB sends an early HO request to a target gNB. The target gNB accepts the HO request and builds a RRC configuration. The target gNB returns a HO request acknowledgment including the RRC configuration to the serving gNB in step 3. In step 4, a conditional HO command with “high” threshold is sent to the UE. Subsequently, measurements by the UE may fulfil the HO condition of the conditional HO command. The UE thus triggers the pending conditional handover. The UE performs synchronization and random access with the target gNB in step 5, and HO confirm is exchanged in step 6. In step 7, target gNB infoms serving gNB that HO is completed. The target gNB may then exchange user plane (UP) data with the UE.

While the UE evaluates the condition, it should continue operating per its current RRC configuration, i.e., without applying the conditional HO command. When the UE determines that the condition is fulfilled, it disconnects from the serving cell, applies the conditional HO command and connects to the target cell. These steps are equivalent to the conventional, instantaneous handover execution. Resume triggered by CHO

Some examples of conditional handover procedures may rely on context fetching, where a condition is also provided to the UE and, upon the fulfillment of the condition, the UE executes a RRC Resume procedure. This may for example comprise a method executed by a UE in RRC connected mode, the method comprising:

Receiving a message containing at least one condition from the network and monitoring the fulfillment of the condition;

Upon the fulfillment of a condition, triggering an RRC Resume procedure or an equivalent procedure towards at least one target cell, node or gNB.

This may be summarized by the flow diagram in Figure 3, which summarizes signalling 300 between a UE, serving node (in this example a serving gNB) and target node (in this example a target gNB) during a conditional RRC Resume procedure. In Figure 3, serving gNB may exchange user plane (UP) data with the UE. In step 1 , the UE sends a measurement report with“low” threshold to serving gNB. The serving gNB makes a HO decision based on this early report. In step 2, the serving gNB sends an early HO request to a target gNB. The target gNB accepts the HO request. The target gNB returns a HO request acknowledgement to the serving gNB in step 3. In step 4, a conditional HO command with“high” threshold is sent to the UE. Subsequently, measurements by the UE may fulfil the HO condition of the conditional HO command. The UE thus triggers the pending conditional handover. The UE performs synchronization and random access with the target gNB in step 5, and in step 6 sends a RRCConnectionResumeRequest message to the target gNB. The target gNB may then exchange user plane data with the UE.

In general terms, both conditional handover and conditional resume may be considered as examples of a conditional mobility procedure.

Inter-node messages for mobility preparation

RRC Inter-node messages

In NR, two inter-node messages are typically used in a handover (HO): HandoverPreparationlnformation and HandoverCommand. When the source node (e.g. the node that is currently serving a UE to be handed over) decides to handover the UE, the source node provides the target node with some information in the HandoverPreparationlnformation that enables the target node to prepare an RRCReconfiguration (provided in the HandoverCommand) be used in target upon handover execution. Definitions from TS 38.331 V15.5.1 are shown below:

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HandoverPreparationlnformation

This message is used to transfer the NR RRC information used by the target gNB during handover preparation, including UE capability information.

Direction: source gNB/source RAN to target gNB.

HandoverPreparationlnformation message

— ASNl START

— TAG-HANDOVER- PREPARATION- 1NFORMATION- START

HandoverPreparationlnformation SEQUENCE {

criticalExtensions CHOICE {

cl CHOICE!

handoverPreparationlnformation HandoverPreparationlnformation-IEs , spare3 NULL, spare2 NULL, sparel NULL

criticalExtens ions Future SEQUENCE { }

HandoverPreparationlnformation-IEs SEQUENCE {

ue-CapabilityRAT-List UE-CapabilityRAT-ContainerList ,

sourceConfig AS-Config OPTIONAL, — Cond HO rrm-Config RRM-Config OPTIONAL, as-Context AS-Context OPTIONAL, nonCriticalExtension SEQUENCE { } OPTIONAL

AS-Config : : = SEQUENCE {

rrcReconfiguration OCTET STRING (CONTAINING RRCReconfiguration) ,

AS-Context : : = SEQUENCE {

reestablishmentInfo ReestablishmentInfo OPTIONAL, configRestrictlnfo ConfigRestrictlnfoSCG OPTIONAL,

[ [ ran-NotificationArealnfo RAN-NotificationArealnfo OPTIONAL

] ]

Reestablishmentlnfo SEQUENCE {

sourcePhysCellld PhysCellld,

targetCell ShortMAC-I ShortMAC- I,

additionalRees tablnfoList ReestabNCellInfoList OPTIONAL

ReestabNCelllnfoList : : SEQUENCE ( SIZE ( 1..maxCellPrep) ) OF ReestabNCelllnfo ReestabNCelllnfo: := SEQUENCE {

cellldentity Cellldentity,

key-gNodeB-Star BIT STRING (SIZE (256)),

shortMAC-I ShortMAC-I

RRM-Config ::= SEQUENCE {

ue-InactiveTime ENUMERATED {

si, s2, s3, s5, s7, slO, sl5, s20,

s25, s30, s40, s50, mini, minls20c, minls40, min2, min2s30, min3, min3s30, min4, min5, min6, in7, in8, in9, inlO, minl2, minl4, minl7, min20 ,

in24, in28, in33, in38, in44, in50, hrl, hrl in30, hr2, hr2 in30, hr3, hr3 in30, hr4, hr5, hr6,

hr8, hrlO, hrl3, hrl6, hr20, dayl, daylhrl2, day2 ,

day2hr!2, day3, day4, day5, day7, daylO, day!4, dayl9,

day24, day30, dayMoreThan30 } OPTIONAL candidateCelllnfoLis t MeasResultList2NR OPTIONAL

— TAG-HANDOVER- PREPARATION- INFORMATION- STOP

— ASN1STOP

NOTE 2: The following table indicates per source RAT whether RAT capabilities are included or not.

HandoverCommand

This message is used to transfer the handover command as generated by the target gNB.

Direction: target gNB to source gNB/source RAN.

HandoverCommand message

— ASNl START

— TAG-HANDOVER-COMMAND- START

HandoverCommand SEQUENCE {

criticalExtensions CHOICE {

cl CHOICE!

handoverCommand HandoverCommand-IEs ,

spare3 NULL, spare2 NULL, sparel NULL

criticalExtens ions Future SEQUENCE { }

HandoverCommand-IEs SEQUENCE {

handoverCommandMes sage OCTET STRING (CONTAINING RRCReconfiguration) , nonCriticalExtension SEQUENCE { } OPTIONAL

— TAG-HANDOVER-COMMAND- STOP

— ASN1STOP

_{******************************************************* *********************}

Xn inter-node messages for handover/DC-setup

According to TS 38.420 V15.2.0, there is a function called“Handover preparation function” defined as follows:

Handover preparation function

This function allows the exchange of information between source and target NG-RAN nodes in order to initiate the handover of a certain UE to the target.

An equivalent function exists for DC setup, called “S-NG-RAN-node Addition Preparation”. Another function that is relevant for the context of this disclosure is the “Handover canceling function” defined as follows:

Handover cancellation function

This function allows informing an already prepared target NG-RAN node that a prepared handover will not take place. It allows releasing the resources allocated during a preparation.

In TS 38.423 V15.3.0 these functions are described in more detail, and relevant parts are inserted below:

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8.2.1 Handover Preparation

8.2.1.2 Successful Operation

The source NG-RAN node initiates the procedure by sending the HANDOVER REQUEST message to the target NG-RAN node. When the source NG-RAN node sends the HANDOVER REQUEST message, it shall start the timer TXn _REL ocp _rep.

At reception of the HANDOVER REQUEST message the target NG-RAN node shall prepare the configuration of the AS security relation between the UE and the target NG-RAN node by using the information in the UE Security Capabilities IE and the AS Security Information IE in the UE Context Information IE, as specified in TS 33.501 [28]

8.2.1.3 Unsuccessful Operation

If the target NG-RAN node does not admit at least one PDU session resource, or a failure occurs during the Handover Preparation, the target NG-RAN node shall send the HANDOVER PREPARATION FAILURE message to the source NG-RAN node. The message shall contain the Cause IE with an appropriate value.

Interactions with Handover Cancel procedure:

If there is no response from the target NG-RAN node to the HANDOVER REQUEST message before timer TXn _REL ocp _rep expires in the source NG-RAN node, the source NG-RAN node should cancel the Handover Preparation procedure towards the target NG-RAN node by initiating the Handover Cancel procedure with the appropriate value for the Cause IE. The source NG-RAN node shall ignore any HANDOVER REQUEST ACKNOWLEDGE or HANDOVER PREPARATION FAILURE message received after the initiation of the Handover Cancel procedure and remove any reference and release any resources related to the concerned Xn UE-associated signalling.

8.2.1.4 Abnormal Conditions

If the supported algorithms for encryption defined in the UE Security Capabilities IE in the UE Context Information IE, plus the mandated support of the EEAO and NEAO algorithms in all UEs (TS 33.501 [28]), do not match any allowed algorithms defined in the configured list of allowed encryption algorithms in the NG-RAN node (TS 33.501 [28]), the NG-RAN node shall reject the procedure using the HANDOVER PREPARATION FAILURE message.

If the supported algorithms for integrity defined in the UE Security Capabilities IE in the UE Context Information IE, plus the mandated support of the EIA0 and NIA0 algorithms in all UEs (TS 33.501 [28]), do not match any allowed algorithms defined in the configured list of allowed integrity protection algorithms in the NG-RAN node (TS 33.501 [28]), the NG-RAN node shall reject the procedure using the HANDOVER PREPARATION FAILURE message.

_{******************************************************* ********************}

Inter-node messages in case of CU/DU split

A gNB can be split into two logical entities, namely gNB-CU (Control Unit) and gNB- DU (Distributed Unit). The same kind of split may be seen if the NG-RAN node is an ng-eNB, with an W1 interface and a respective Application Protocol with almost the same functions as F1AP). The interface between these 2 nodes is called F1. Overall architecture is described in TS 38.401 V15.5.0 section 6.1.1.

Examples of handover procedures involving these network nodes can be found in TS 38.401 V15.5.0. The messages exchanged on the F1 interface during these procedures are defined in TS 38.473 V15.5.0. For example, in case of Inter-gNB-DU Mobility (i.e. source access node and target access node are part of the same logical entity/gNB/NG-RAN node but the Handover procedure is performed between 2 different gNB-DUs), the procedure is described in TS 38.401 V15.5.0 as reproduced below:

_{******************************************************* ********************}

8.2.1.1 Inter-gNB-DU Mobility

This procedure is used for the case when the UE moves from one gNB-DU to another gNB-DU within the same gNB-CU during NR operation. Figure 8.2.1.1-1 [included herein as Figure 4] shows the inter-gNB-DU mobility procedure for intra-NR.

1. The UE sends a MeasurementReport message to the source gNB-DU.

2. The source gNB-DU sends an UL RRC MESSAGE TRANSFER message to the gNB-CU to convey the received MeasurementReport message.

3. The gNB-CU sends an UE CONTEXT SETUP REQUEST message to the target gNB-DU to create an UE context and setup one or more bearers.

4. The target gNB-DU responds to the gNB-CU with an UE CONTEXT SETUP RESPONSE message.

5. The gNB-CU sends a UE CONTEXT MODIFICATION REQUEST message to the source gNB-DU, which includes a generated RRCReconfiguration message and indicates to stop the data transmission for the UE. The source gNB-DU also sends a Downlink Data Delivery Status frame to inform the gNB-CU about the unsuccessfully transmitted downlink data to the UE.

6. The source gNB-DU forwards the received RRCReconfiguration message to the UE.

7. The source gNB-DU responds to the gNB-CU with the UE CONTEXT MODIFICATION RESPONSE message. 8. A Random Access procedure is performed at the target gNB-DU. The target gNB- DU sends a Downlink Data Delivery Status frame to inform the gNB-CU. Downlink packets, which may include PDCP PDUs not successfully transmitted in the source gNB-DU, are sent from the gNB-CU to the target gNB-DU.

NOTE: It is up to gNB-CU implementation whether to start sending DL User Data to gNB-DU before or after reception of the Downlink Data Delivery Status.

9. The UE responds to the target gNB-DU with an RRCReconfigurationComplete message.

10. The target gNB-DU sends an UL RRC MESSAGE TRANSFER message to the gNB-CU to convey the received RRCReconfigurationComplete message. Downlink packets are sent to the UE. Also, uplink packets are sent from the UE, which are forwarded to the gNB- CU through the target gNB-DU.

1 1. The gNB-CU sends an UE CONTEXT RELEASE COMMAND message to the source gNB-DU.

12. The source gNB-DU releases the UE context and responds the gNB-CU with an UE CONTEXT RELEASE COMPLETE message.

_{******************************************************* ********************}

In the case of inter-node mobility (e.g. source gNB and target gNB-CU are different logical nodes), UE Context Setup procedures may be used over the F1 interface, on the target node side (e.g. between the target gNB-CU and the target gNB-DU), in order to establish a new UE context in the target nodes. This procedure is defined in TS 38.473 V15.5.0.

Another case is intra-DU mobility when the UE moves from one cell to another cell within the same gNB-DU, or where intra-cell handover is performed during NR operation. These cases are supported by the UE Context Modification (gNB-CU initiated) procedure over the F1 interface, as specified in TS 38.473 V15.5.0. When intra-cell handover is performed, the gNB-CU provides a new UL GPRS Tunneling Protocol (GTP) Tunnel Endpoint Identifier (TEID) to the gNB-DU, and the gNB-DU provides new DL GTP TEID to the gNB-CU. The gNB-DU shall continue sending UL PDCP PDUs to the gNB-CU with the previous UL GTP TEID until it re-establishes the RLC, and use the new UL GTP TEID after RLC re establishment. The gNB-CU shall continue sending DL PDCP PDUs to the gNB-DU with the previous DL GTP TEID until it performs PDCP re-establishment or PDCP data recovery, and use the new DL GTP TEID starting with the PDCP re-establishment or data recovery. Inter-node messages in case of separation of gNB-CU-CP and gNB-CU-UP

A gNB-CU can be split between two logical entities, namely gNB-CU-CP (control unit- control plane) for the control plane functions and gNB-CU-UP (control unit-user plane) for the user plane functions. The interface between these two nodes is called E1. Such architecture is described in TS 38.401 V15.5.0 section 6.1.2.

Examples of handover procedures involving these network nodes can be found in TS 38.401 V15.5.0. The messages exchanged on the E1 interface during these procedures are defined in TS 38.463 V15.5.0. For example, in case of Inter-gNB handover involving gNB- CU-UP change, the procedures are described in TS 38.401 V15.5.0 and are reproduced below.

_{******************************************************* ***************}

8.9.4 Inter-gNB handover involving gNB-CU-UP change

Figure 8.9.4-1 [included herein as Figure 5] shows the procedure used for inter-gNB handover involving gNB-CU-UP change. Overall inter-gNB handover procedure is specified in TS 37.340.

1. The source gNB-CU-CP sends HANDOVER REQUEST message to the target gNB-CU-CP.

2-4. Bearer context setup procedure is performed as described in Section 8.9.2.

5. The target gNB-CU-CP responds the source gNB-CU-CP with an HANDOVER REQUEST ACKNOWLEDGE message.

6. The F1 UE Context Modification procedure is performed to stop UL data transmission at the gNB-DU and to send the handover command to the UE.

7-8. Bearer context modification procedure (gNB-CU-CP initiated) is performed to enable the gNB-CU-CP to retrieve the PDCP UL/DL status and to exchange data forwarding information for the bearer.

9. The source gNB-CU-CP sends an SN STATUS TRANSFER message to the target gNB-CU-CP.

10-11. Bearer context modification procedure is performed as described in Section

8.9.2. 12. Data Forwarding may be performed from the source gNB-CU-UP to the target gNB-CU-UP.

13-15. Path Switch procedure is performed to update the DL TNL address information for the NG-U towards the core network.

16. The target gNB-CU-CP sends an UE CONTEXT RELEASE message to the source gNB-CU-CP.

17. and 19. Bearer context release procedure is performed.

18. F1 UE context release procedure is performed to release the UE context in the source gNB-DU.

8.9.5 Change of gNB-CU-UP

Figure 8.9.5-1 [included herein as Figure 6] shows the procedure used for the change of gNB-CU-UP within a gNB.

1. Change of gNB-CU-UP is triggered in gNB-CU-CP based on e.g., measurement report from the UE.

2-3. Bearer Context Setup procedure is performed as described in Section 8.9.2.

4. F1 UE Context Modification procedure is performed to change the UL TNL address information for F1-U for one or more bearers in the gNB-DU.

5-6. Bearer Context Modification procedure (gNB-CU-CP initiated) is performed to enable the gNB-CU-CP to retrieve the PDCP UL/DL status and to exchange data forwarding information for the bearer.

7-8. Bearer Context Modification procedure is performed as described in Section 8.9.2.

9. Data Forwarding may be performed from the source gNB-CU-UP to the target gNB-CU-UP.

10-12. Path Switch procedure is performed to update the DL TNL address information for the NG-U towards the core network.

13-14. Bearer Context Release procedure (gNB-CU-CP initiated) is performed as described in Section 8.9.3.

_{******************************************************* ***************} In handovers comprising gNB-CU-CP and gNB-CU-UP, the procedures involved over the E1 interface are Bearer Context Setup and Bearer Context Modification. These procedures are described in detail in TS 38.463 V15.5.0. These procedure may be used where the UE moves from one cell to another cell within the same gNB-DU or for the case that intra-cell handover is performed during NR operation, and supported by UE Context Modification (gNB-CU initiated) procedure as specified in TS 38.473 V15.5.0. When intra-cell handover is performed, the gNB-CU provides a new UL GTP TEID to the gNB-DU and gNB- DU provides new DL GTP TEID to the gNB-CU. The gNB-DU shall continue sending UL PDCP PDUs to the gNB-CU with the previous UL GTP TEID until it re-establishes the RLC, and use the new UL GTP TEID after RLC re-establishment. The gNB-CU shall continue sending DL PDCP PDUs to the gNB-DU with the previous DL GTP TEID until it performs PDCP re-establishment or PDCP data recovery, and use the new DL GTP TEID starting with the PDCP re-establishment or data recovery.

Problems with existing solutions such as those referred to above may include those related to the preparation phase and execution phase of a conditional handover (CHO) in a DU/CU split architecture. During the preparation phase, existing procedures in the state of the art are defined for allocating resources in CU and/or DU (depending on the source cell and target candidate cell(s) for CHO). This may be suitable for cases where the UE is expected to execute the HO and utilize these resources (except in some failure cases).

However, in CHO, the source gNodeB may configure the UE with multiple CHO configurations (e.g. multiple RRCReconfiguration(s) with associated ReconfigurationWithSync ) associated to multiple cells that are target candidates, where these candidate target cells may be for example from the same CU/DU as the serving cell, or from the same CU as the serving cell but different DU, or from different CU and different DU than the serving cell. These configurations are associated to resources that need to be reserved, possibly by different nodes (e.g. different DU and/or different CUs).

Intra/inter-DU-gNodeB mobility

In the intra-DU case, existing procedures define that upon receiving a measurement report, the control unit (CU) may send a UE CONTEXT MODIFICATION REQUEST message to the distributed unit (DU). Upon reception of the UE CONTEXT MODIFICATION REQUEST message, the gNB-DU shall perform the modifications, and, if successful, report the update in the UE CONTEXT MODIFICATION RESPONSE message. In the case of a handover, for example, the CU includes an SpCell ID for the target cell in the UE CONTEXT MODIFICATION REQUEST message, so the gNB-DU replaces any previously received value. At that point, the potential target DU (which in this case is the same as the source DU) expects the UE to perform random access and, after receiving a HO complete (e.g. an RRCReconfigurationComplete message) from the UE, to forward it to the CU. Once the CU receives the RRCReconfigurationComplete it sends a UE CONTEXT RELEASE COMMAND to the DU. Hence, in the existing procedures, upon receiving a UE CONTEXT MODIFICATION REQUEST message, the DU performs the modifications, reserves resources for an incoming UE and sends an acknowledgement to the CU. But with CHO, different scenarios may occur, such as for example:

It may take some time until the UE executes the HO, since the UE shall first start to perform monitoring conditions and only executes the HO when/if the conditions are fulfilled.

The UE may never execute the HO and may remain connected to the source cell/DU/CU;

The UE may execute a HO to another cell of another DU or CU, etc;

- Any other abnormal failure case.

Any of these cases may be problematic for the DU, for example if one or more potential target DUs define resource timers to detect HO failures and release resources after some time (in which case e.g. a DU may release resources before or around a time when a UE attempts to connect to it via CHO). Alternatively, the DU may reserve these resources for an indefinite amount of time, even after the UE connects to another DU or does not handover at all.

In the inter-DU/intra-CU case, UE CONTEXT SETUP REQUEST message is used instead, and instead of modifying an existing context for a UE that may never connect (as in intra DU case) the DU will setup a new UE context for a UE that may never connect (because it may handover to another cell or remain connected to the source cell) or connects after too long a time, leading to similar problems. Similar problems regarding reservation of resources for potential target gNB-CU-UP via BEARER CONTEXT SETUP REQUEST message may also occur.

In general, the way a gNB-DU allocates resources to a UE during mobility is based on the“imminent arrival” of the UE. The gNB-DU could for example need to de-allocate resources from other UEs in order to admit the incoming UE, and while the gNB-DU is waiting for the UE to connect, the gNB-DU may need to keep this resource status (e.g. de-allocate resources to lower priority UEs, while freezing resources while waiting for the incoming UE). In summary, for example, at reception of UE CONTEXT SETUP REQUEST (or UE CONTEXT MODIFICATION REQUEST) or BEARER CONTEXT SETUP REQUEST (or BEARER CONTEXT MODIFICATION REQUEST), the potential target base station (e.g. gNB- DU) or the potential target base station (e.gl gNB-CU-UP), respectively, are not aware that these messages and the resources needed to satisfy these requests are related to a conditional handover. The potential target base station (e.g. gNB-DU) and the potential target base station (e.g. gNB-CU-UP) may therefore reserve resources for UEs that have a significant possibility to for example:

Perform handover after a much longer time than the expected (legacy) handover Perform a handover to a different potential target node

Remain connected to the source and not perform any handover

The problems associated with this may be for example over-provisioning of resources, incorrect timer value setup, incorrect cancellation decision, incorrect error cases handling, and/or incorrect KPIs or measurements reporting.

Summary

Certain aspects of the present disclosure and their embodiments may provide solutions to these or other challenges. One aspect of the present disclosure provides a method in a network node. The network node comprises an eNB-CU or gNB-CU. The method comprises sending a message to a base station to prepare the base station for a mobility procedure by a User Equipment (UE) to a target cell associated with the base station, wherein the message indicates that the mobility procedure is associated with a condition, and the base station comprises an eNB-CU-UP, eNB-DU, gNB-CU-UP or gNB-DU.

Another aspect of the present disclosure provides a method in a base station. The base station comprises an eNB-CU-UP, eNB-DU, gNB-CU-UP or gNB-DU. The method comprises receiving a message from a network node to prepare the base station for a mobility procedure by a User Equipment (UE) to a target cell associated with the base station, wherein the message indicates that the mobility procedure is associated with a condition, wherein the network node comprises an eNB-CU or gNB-CU. A further aspect of the present disclosure provides apparatus in a network node. The network node comprises an eNB-CU or gNB-CU. The apparatus comprises a processor and a memory. The memory contains instructions executable by the processor such that the apparatus is operable to send a message to a base station to prepare the base station for a mobility procedure by a User Equipment (UE) to a target cell associated with the base station, wherein the message indicates that the mobility procedure is associated with a condition, and the base station comprises an eNB-CU-UP, eNB-DU, gNB-CU-UP or gNB-DU.

A still further aspect of the present disclosure provides apparatus in a base station. The base station comprises an eNB-CU-UP, eNB-DU, gNB-CU-UP or gNB-DU. The apparatus comprises a processor and a memory. The memory contains instructions executable by the processor such that the apparatus is operable to receive a message from a network node to prepare the base station for a mobility procedure by a User Equipment (UE) to a target cell associated with the base station, wherein the message indicates that the mobility procedure is associated with a condition, wherein the network node comprises an eNB-CU or gNB-CU.

An additional aspect of the present disclosure provides apparatus in a network node. The network node comprises an eNB-CU or gNB-CU. The apparatus is configured to send a message to a base station to prepare the base station for a mobility procedure by a User Equipment (UE) to a target cell associated with the base station, wherein the message indicates that the mobility procedure is associated with a condition, and the base station comprises an eNB-CU-UP, eNB-DU, gNB-CU-UP or gNB-DU.

Another aspect of the present disclosure provides apparatus in a base station. The base station comprises an eNB-CU-UP, eNB-DU, gNB-CU-UP or gNB-DU. The apparatus is configured to receive a message from a network node to prepare the base station for a mobility procedure by a User Equipment (UE) to a target cell associated with the base station, wherein the message indicates that the mobility procedure is associated with a condition, wherein the network node comprises an eNB-CU or gNB-CU.

Brief Description of the Drawings

For a better understanding of examples of the present disclosure, and to show more clearly how the examples may be carried into effect, reference will now be made, by way of example only, to the following drawings in which: Figure 1 summarizes signalling between a UE, source node and target node during a handover procedure;

Figure 2 summarizes signalling between a UE, serving node and target node during a conditional handover procedure;

Figure 3 summarizes signalling between a UE, serving node and target node during a conditional RRC Resume procedure;

Figure 4 shows Figure 8.2.1.1-1 : Inter-gNB-DU Mobility for intra-NR from TS 38.401 V15.5.0;

Figure 5 shows Figure 8.9.4-1 : Inter-gNB handover involving gNB-CU-UP change from TS 38.401 V15.5.0;

Figure 6 shows Figure 8.9.5-1 : Change of gNB-CU-UP from TS 38.401 V15.5.0;

Figure 7 shows an example of a method in a network node;

Figure 8 shows an example of a method in base station;

Figure 9 shows an example implementation of a method of conditional handover for inter-node mobility;

Figure 10 shows an example of a wireless network in accordance with some embodiments;

Figure 11 shows an example of a User Equipment (UE) in accordance with some embodiments;

Figure 12 is a schematic block diagram illustrating a virtualization environment in accordance with some embodiments;

Figure 13 shows a telecommunication network connected via an intermediate network to a host computer in accordance with some embodiments;

Figure 14 shows a host computer communicating via a base station with a user equipment over a partially wireless connection in accordance with some embodiments;

Figure 15 shows methods implemented in a communication system in accordance with some embodiments;

Figure 16 shows methods implemented in a communication system in accordance with some embodiments;

Figure 17 shows methods implemented in a communication system in accordance with some embodiments; Figure 18 shows methods implemented in a communication system including a host computer, a base station and a user equipment in accordance with some embodiments; and

Figure 19 illustrates a schematic block diagram of virtualization apparatus in accordance with some embodiments.

Detailed Description

The following sets forth specific details, such as particular embodiments or examples for purposes of explanation and not limitation. It will be appreciated by one skilled in the art that other examples may be employed apart from these specific details. In some instances, detailed descriptions of well-known methods, nodes, interfaces, circuits, and devices are omitted so as not obscure the description with unnecessary detail. Those skilled in the art will appreciate that the functions described may be implemented in one or more nodes using hardware circuitry (e.g., analog and/or discrete logic gates interconnected to perform a specialized function, ASICs, PLAs, etc.) and/or using software programs and data in conjunction with one or more digital microprocessors or general purpose computers. Nodes that communicate using the air interface also have suitable radio communications circuitry. Moreover, where appropriate the technology can additionally be considered to be embodied entirely within any form of computer-readable memory, such as solid-state memory, magnetic disk, or optical disk containing an appropriate set of computer instructions that would cause a processor to carry out the techniques described herein.

Hardware implementation may include or encompass, without limitation, digital signal processor (DSP) hardware, a reduced instruction set processor, hardware (e.g., digital or analogue) circuitry including but not limited to application specific integrated circuit(s) (ASIC) and/or field programmable gate array(s) (FPGA(s)), and (where appropriate) state machines capable of performing such functions.

The term“conditional mobility” or“conditional mobility procedure” is used herein to refer to (for example) conditional handover, conditional resume, conditional reconfiguration with sync, conditional reconfiguration, conditional reestablishment, etc. The term should be interpreted fundamentally as any procedure that is configured by network to the UE which contains a condition (e.g. associated to measurement event) and, upon the triggering of that condition the UE shall perform the mobility related procedure e.g. resume, handover, reconfiguration with sync, beam switching, etc. In some examples, without loss of generality, methods described herein refer to the example case of a high layer split architecture supporting the NR RAT. Equivalent functions may also be expected for RAN nodes that follow a similar high layer split architecture, such as for example for eNBs split into CU/DU and CU-CP/CU-UP. Therefore, methods described herein are equally applicable to NG-RAN nodes providing E-UTRA or to E-UTRAN nodes or to any other suitable wireless communication technologies. For example:

Methods for gNB-CU-CP are applicable to a CU-CP part of an eNB in both E-UTRAN or NG-RAN

Methods for gNB-CU-UP are applicable to a CU-UP part of an eNB in both E-UTRAN or NG-RAN

Methods for gNB-DU are applicable to a DU part of an eNB in both E-UTRAN or NG- RAN

Methods for gNB-CU are applicable to a CU part of an eNB in both E-UTRAN or NG- RAN

These examples may also be applicable to other network technologies.

Embodiments of this disclosure include for example a method at a potential target gNB- CU-CP that receives a conditional handover preparation message from a source gNB for a UE. In an example, a method comprises:

Including a conditional handover indicator in messages aimed at creating a UE context for the purpose of mobility of the UE to the potential target gNB-DU, e.g. UE Context Setup Request message sent to a target candidate gNB-DU over F1 interface, for handovers where UE Context Setup procedure is used;

Including a conditional handover indicator in messages aimed at creating a UE context for the purpose of intra gNB-DU mobility of the UE, e.g. UE Context Modification messages sent to the target candidate gNB-DU over F1 interface, for handovers where UE Context Modification procedure is used;

Including an indicator in messages aimed at creating a bearer context for the purpose of mobility of the UE to a potential target gNB-CU-UP, e.g. Bearer Context Setup messages sent to the potential target gNB-CU-UP over E1 interface, for handovers where Bearer Context Setup procedure is used; Including an indicator in messages aimed at modifying a bearer context for the purpose of intra gNB-CU-UP mobility of the UE, e.g. Bearer Context Modification messages sent to the potential target gNB-CU-UP over E1 interface, for handovers where Bearer Context Modification procedure is used.

A target candidate gNB-DU in this case is for example a DU with an associated target candidate cell for which that CU wants to configure CHO for a given UE.

In an alternative embodiment, one or more different messages (instead of an indication) may be used, e.g. Conditional UE Context Setup/Modification request message, to indicate that this setup/modification request is associated to a CHO instead of e.g. a legacy HO. Thus for example the message may have a type that is specific to conditional handovers.

The message may also in some examples include a timer value related to the validity of that UE/bearer context or pending modification. In other words, the potential target gNB- CU-CP may indicate for how long it expects the base station (e.g. gNB-DU or gNB-CU-UP) to wait for an incoming UE (and also expects the gNB-DU or the gNB-CU-UP to release the UE/bearer context upon the expiry of the timer). The timer value therefore allows the potential target gNB-DU and gNB-CU-UP to release the resources reserved for the incoming UE after the timer expires and/or it allows the potential target gNB-DU and gNB-CU-UP to adopt appropriate RRM policies for other served UEs during such timer duration, in light of the possible event that resources may need to be de-allocated from other served UEs and reserved to the incoming UE. (In this disclosure, where a particular type of node is referred to e.g. gNB-DU, gNB-CU-UP etc, this may be read as being non-limiting examples of general base stations and/or network nodes, where appropriate.)

Embodiments of this disclosure include for example a method at a potential target gNB- DU that receives a conditional handover indicator from a potential target gNB-CU-CP for a UE, the method comprising:

Receiving a conditional handover indicator in messages aimed at creating a UE context for the purpose of mobility of the UE to the potential target gNB-DU, e.g. UE Context Setup messages sent by the potential target gNB-CU-CP over F1 interface, for handovers where UE Context Setup procedure is used

Receiving a conditional handover indicator in messages aimed at creating a UE context for the purpose of intra gNB-DU mobility of the UE, e.g. UE Context Modification messages sent by the potential target gNB-CU-CP over F1 interface, for handovers where UE Context Modification procedure is used Upon reception of a conditional handover indicator in e.g. UE Context Setup or UE Context Modification messages received from a potential target gNB-CU-CP, taking educated UE Context Setup establishment or modification decisions, taking into consideration the conditionality of the handover. These decisions can be, for example:

o A softer resource reservation, for example allocation of resources only for the bearers that would suffer of critical performance degradation if such resources are not made immediately available upon UE connection

o A dedicated RRM policy for other served UEs, for example allowing other served UEs to use as much as possible the resources allocated to them despite full admission of the bearers of the conditionally incoming UE may imply a higher reduction of resources allocated to existing UEs

o The start of a resource reservation timer

Embodiments of this disclosure include for example a method at a potential target gNB- CU-UP that receives a conditional handover indicator from a potential target gNB-CU-CP for a UE, the method comprising:

Receiving a conditional handover indicator in messages aimed at creating a bearer context for the purpose of mobility of the UE to a potential target gNB-CU-UP, e.g. Bearer Context Setup messages sent by the potential target gNB-CU-CP over E1 interface, for handovers where Bearer Context Setup procedure is used

Receiving a conditional handover indicator in messages aimed at modifying a bearer context for the purpose of intra gNB-CU-UP mobility of the UE, e.g. Bearer Context Modification messages sent by the potential target gNB-CU-CP over E1 interface, for handovers where Bearer Context Modification procedure is used

Upon reception of a conditional handover indicator in Bearer Context Setup or Bearer Context Modification messages received from a potential target gNB-CU-CP, taking Bearer Context Setup establishment or modification decisions, taking into consideration the conditionality of the handover. These decisions can be, for example:

o A softer resource reservation, for example allocation of resources only for the bearers that would suffer from critical performance degradation if such resources are not made immediately available upon UE connection

o A dedicated RRM policy for other served UEs, for example allowing other served UEs to use as much as possible the resources allocated to them despite full admission of the bearers of the conditionally incoming UE may imply a higher reduction of resources allocated to existing UEs

o The start of a resource reservation timer

o To delay the start of the inactivity timer for this UE

Embodiments of this disclosure include for example a method at a gNB-DU prepared for a HO (e.g. CHO) execution for multiple cells associated to it. And, upon detecting that the UE accesses one of its candidate target cells (e.g. by detecting a contention free random- access resource, like a preamble or, by detection of an allocated C-RNTI), the gNB-DU releases the resources associated to other candidate target cells associated to it, and forwards the RRCReconfigurationComplete from the UE executing the HO. This may be considered an optimization whose advantage is that for example this gNB-DU does not need to receive yet another message from its gNB-CU before releasing the reserved resources for cells prepared but not accessed by the UE as such resources will not be utilized.

Embodiments of this disclosure include or example a method at a gNB-CU-CP associated to a candidate target gNB-DU where resources have been allocated for CHO (e.g. according to CHO preparation procedure described above), the method comprising:

Upon detecting the HO execution (e.g. triggered by CHO or by a network-triggered HO) triggering the release of the resources in all candidate target gNB-DUs where a HO was prepared but not executed;

o The execution may be detected by the reception of an

RRCReconfigurationComplete forwarded by the gNB-DU where the execution occurred.

That release procedure may be done by sending a UE CONTEXT RELEASE COMMAND. That may include an indication that CHO or HO has been executed in another cell (e.g. from another gNB-DU and/or gNB-CU).

That gNB-CU-CP associated to a candidate target gNB-DU may be the gNB-CU that is both source and target (e.g. in case of inter- gNB-DU intra- gNB-CU HO is being executed). In that case this gNB-CU receives a transferred

RRCReconfigurationComplete from the gNB-DU where the HO is executed and triggers the action to release the context in the gNB-DUs where the context is not executed. Upon detecting the HO execution (e.g. triggered by CHO or by a network-triggered HO) triggering the release of the resources in the partitions of the gNB-CU-CP associated to the prepared target gNB-DUs and cells where a HO was prepared but not executed. Namely, the gNB-CU-CP maybe partitioned in different modules serving specific gNB-DUs and cells and resources may be reserved in each such modules upon preparation of corresponding gNB-DUs and cells. Hence the de-allocation of resources in the modules that will not serve the UE happens upon identification for the module that will serve the UE.

There are, proposed herein, various embodiments which address one or more of the issues disclosed herein, such as for example one or more of the problems identified above. For example, embodiments of this disclosure include a method in a network node, the method comprising sending a message to a base station to prepare the base station for a mobility procedure by a User Equipment (UE) to a target cell associated with the base station, wherein the message indicates that the mobility procedure is associated with a condition. Embodiments of this disclosure also include, for example, a method in base station, the method comprising receiving a message from a network node to prepare the base station for a mobility procedure by a User Equipment (UE) to a target cell associated with the base station, wherein the message indicates that the mobility procedure is associated with a condition.

Equivalent functions may also be expected or are already specified in case of handovers to/from ng-eNBs split into CU/DU and CU-CP/CU-UP, so methods described herein are equally applicable to for example NG-RAN nodes providing E-UTRA, and/or any other suitable RAT or other wireless communications technologies.

If the gNB-DU knows that the UE handing over is not necessarily connecting in the immediate future, the gNB-DU may decide to adopt different radio resource management functions. A problem is therefore for example how to make the gNB-DU aware of such particular mobility condition to allow the gNB-DU to optimize its radio resource management.

Certain embodiments may provide one or more of the following technical advantage(s). For example, compared to existing procedures for handover, advantages of embodiments of this disclosure include for example that during the handover preparation where the potential target gNB (or more generally a base station) is disaggregated (i.e. split in gNB-CU-CP, gNB- CU-UP and gNB-DU entities), the potential target gNB-CU-UP and potential target gNB-DU are aware that the UE Context Setup/Modification procedures are linked to a conditional handover. It gives the possibility to the potential target gNB-CU-UP and the potential target gNB-DU to take educated Bearer Context Setup establishment or modification decisions. The potential target gNB-CU-CP will also be able to cancel resources in potential gNB-DUs and potential gNB-CU-UPs which were not used. This will result in better resource management and utilization in potential target gNB-CU-UPs and potential target gNB-DUs.

Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Other embodiments, however, are contained within the scope of the subject matter disclosed herein, the disclosed subject matter should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

In an example, a method 700 in a network node is provided as shown in Figure 7. The network node comprises an eNB-CU or gNB-CU. The method 700 comprises, in step 702, sending a message to a base station to prepare the base station for a mobility procedure by a User Equipment (UE) to a target cell associated with the base station, wherein the message indicates that the mobility procedure is associated with a condition. The base station comprises an eNB-CU-UP, eNB-DU, gNB-CU-UP or gNB-DU. Thus, for example, the base station, BS (which is e.g. a target BS or potential target BS, and may be one of multiple target BSs), will be aware that the message pertains to preparations for a conditional handover, and may take appropriate action, such as for example appropriate management of resources, timers etc. in a manner that is advantageous when dealing with conditional handovers. In some examples, the network node comprises a gNB-CU-CP or eNB-CU-CP.

In some examples, the message indicates that the UE will carry out the mobility procedure upon determining that the condition has been met. Additionally or alternatively, the message contains an indication that indicates that the mobility procedure is associated with the condition.

The message may in some examples have a type that is associated with mobility procedures that are associated with conditions. For example, a message may have a type (e.g. UE CONTEXT MODIFICATION REQUEST, RRCReconfigurationComplete etc), and this type may be associated with conditional handovers. For example, new messages may be defined that are particular to conditional handovers.

In some examples, the message further indicates that the preparation for the mobility procedure by the base station is associated with an expiry timer. Thus, for example, the base station could upon expiry of the timer determine that the mobility procedure (e.g. conditional handover, etc) will not be executed by the UE. In some examples, the message further identifies a value for the expiry timer, though instead the base station could determine the value or it may have a default value. In some examples, the method comprises determining that the UE has carried out the mobility procedure. This may comprise for example receiving a

RRCReconfigurationComplete message from the base station. In some examples, the method may comprise, after determining that the UE has carried out the mobility procedure, causing each of at least one further base station to release resources reserved in a respective further target cell for the UE for a respective further mobility procedure associated with a respective further condition. This may comprise for example sending one or more messages to one or more base stations associated with the further target cell(s) to inform them that the mobility procedure will not be executed by the UE to that cell, for example, or to otherwise cause the base station(s) to release resources associated with the mobility procedure to those cell(s). Alternatively, or additionally, this may comprise the network node implementing the method releasing the resources, e.g. where the network node is another base station or is another network node that reserves resources or other assets for one or more mobility procedures for the UE.

In some examples, the base station comprises a gNB-DU, gNB-CU-UP or eNB-DU. In some examples, the network node comprises a gNB-CU, gNB-CU-CP or eNB-CU.

In some examples, the network node comprises a plurality of modules, each module associated with a respective one of the base station and at least one further base station. The base station and the at least one further base station may each comprise a respective gNB- CU-UP, eNB-CU-UP, gNB-DU or eNB-DU. The method may thus comprise, for example, reserving, in each module, resources for the UE, the resources associated with the respective one of the base station and the at least one further base station, and/or the resources being associated with a cell associated with the respective one of the base station and the at least one further base station; and after determining that the UE has carried out the mobility procedure, causing at least one of the modules to release the respective resources. Thus resources can be released in network nodes other than base station(s), for example.

The message may in some examples comprise a message to set up or modify a UE context and/or a bearer context for the mobility procedure. For example, the message may comprise a UE Context Setup Request message, a UE Context Modification Request message, a Bearer Context Setup Request message or a Bearer Context Modification Request message.

Sending the message may in some examples comprise sending the message over at least a W1 interface, F1 interface and/or an E1 interface. The mobility procedure may in some examples comprise a conditional handover, conditional resume, conditional reconfiguration with sync, conditional reconfiguration or conditional reestablishment procedure. More generally, the mobility procedure may comprise for example any procedure that may be executed by the UE to change its serving cell to a target cell, and may for be associated with a condition that causes the UE to execute the handover when the UE determines that the condition has been met. In some examples, the condition comprises for example whether a signal strength of the target cell associated with the base station is greater than a signal strength of a serving cell of the UE by a first threshold, and/or whether the signal strength of the target cell is greater than a signal strength threshold.

In another example, a method 800 in base station is provided as shown in Figure 8. The base station comprises an eNB-CU-UP, eNB-DU, gNB-CU-UP or gNB-DU. The method 800 comprises, in step 802, receiving a message from a network node to prepare the base station for a mobility procedure by a User Equipment (UE) to a target cell associated with the base station, wherein the message indicates that the mobility procedure is associated with a condition. The network node comprises an eNB-CU or gNB-CU. In some examples, the network node comprises a gNB-CU-CP or eNB-CU-CP.

In some examples, the method comprises reserving resources for the UE in the target cell based on the indication that the mobility procedure is associated with a condition. That is, for example, the base station may use the knowledge that the mobility procedure is associated with a condition (e.g. it is a conditional mobility procedure or CHO) to take appropriate action when reserving resources for the mobility procedure. For example, the appropriate action may comprise soft resource reservation as suggested above, and/or any other action relating to resources, timers and/or other parameters that could be handled in a different manner if the mobility procedure is conditional, as compared to non-conditional mobility procedures.

In some examples, the message further indicates that the UE will carry out the mobility procedure upon determining that the condition has been met.

The message may for example contain an indication that indicates that the mobility procedure is associated with the condition. Additionally or alternatively, the message may for example have a type that is associated with mobility procedures that are associated with conditions.

In some examples, the message further indicates that the preparation for the mobility procedure by the base station is associated with an expiry timer. The message may in some examples further identifies a value for the expiry timer. Additionally or alternatively, the method 800 may comprise starting the expiry timer upon receipt of the message and/or upon reserving resources for the UE in the target cell. The method 800 may in some examples also further comprise releasing resources reserved for the UE in the target cell upon expiry of the expiry timer.

In some examples, the method 800 comprises determining that the UE has carried out the mobility procedure. Determining that the UE has carried out the mobility procedure may in some examples comprise detecting receipt of a contention free random-access resource, a preamble and/or a C-RNTI from the UE. The method 800 may in some examples further comprise, after determining that the UE has carried out the mobility procedure, causing each of at least one further base station to release resources reserved in a respective further target cell for the UE for a respective further mobility procedure associated with a respective further condition. Causing each of at least one further base station to release resources may in some examples comprise sending a RRCReconfigurationComplete message to the network node.

The message may comprise for example a message to set up or modify a UE context and/or a bearer context for the mobility procedure. For example, the message may comprise a UE Context Setup Request message, a UE Context Modification Request message, a Bearer Context Setup Request message or a Bearer Context Modification Request message. Receiving the message (e.g. as in step 802) may comprise for example receiving the message over at least a W1 interface, F1 interface and/or an E1 interface.

The mobility procedure may in some examples comprise a conditional handover, conditional resume, conditional reconfiguration with sync, conditional reconfiguration or conditional reestablishment procedure. In some examples, the condition comprises for example whether a signal strength of the target cell associated with the base station is greater than a signal strength of a serving cell of the UE by a first threshold, and/or whether the signal strength of the target cell is greater than a signal strength threshold

Particular example embodiments will now be described.

Conditional mobility

Herein, the term“conditional mobility,”“mobility procedure associated with a condition” or“conditional mobility procedure” is been used to refer to conditional handover, conditional resume, conditional reconfiguration with sync, conditional reconfiguration, conditional reestablishment, etc. The term should be interpreted in some examples as any procedure that is configured by network to the UE which contains a condition (e.g. associated to measurement event) and, upon the triggering of that condition, the UE shall perform the mobility related procedure e.g. resume, handover, reconfiguration with sync, beam switching, etc. Embodiments of this disclosure relate to a conditional mobility configuration associated to a single cell or to multiple cells. In other words, the signaling mechanism triggered by the target candidate gNB-CU-CP towards the target candidate gNB-CU-UP and target candidate gNB-DU may be part of the following alternatives:

a single conditional handover for a single UE that has a target cell in the target node as a candidate for conditional handover;

multiple conditional handovers for a single UE that has at least one target cell in the target node as a candidate for conditional handover;

multiple conditional handovers for multiple UEs that have at least one target cell in the target node as a candidate for conditional handover;

all conditional handovers for multiple UEs that have at least one target cell in the target node as a candidate for conditional handover.

Network aspects

The example methods described below apply to all the RAN nodes following a high layer split architecture. Without loss of generality, the method and embodiments described below are applicable to the following handover cases where the target gNB consists of (a gNB- CU and a gNB-DU) or (a gNB-CU-CP, a gNB-CU-UP and a gNB-DU):

o Inter-node handover (i.e. source and target gNB are two different logical nodes) o Intra-gNB-CU-CP handover with gNB-DU and gNB-CU-UP change o Intra-gNB-CU-CP handover with gNB-DU change

o Intra-gNB-CU-CP handover with gNB-CU-UP change

Equivalent functions may also be expected for RAN nodes that follow a similar high layer split architecture. For example, in case eNBs split into CU/DU and CU-CP/CU-UP. Therefore, example methods described below are equally applicable to NG-RAN nodes providing E-UTRA or to E-UTRAN nodes:

Methods for gNB-CU-CP are applicable to CU-CP part of an eNB in both E-UTRAN or NG-RAN

Methods for gNB-CU-UP are applicable to CU-UP part of an eNB in both E-UTRAN or NG-RAN Methods for gNB-DU are applicable to DU part of an eNB in both E-UTRAN or NG- RAN

In an example, upon the reception of a Conditional Handover Request from the source gNB, the potential target gNB-CU-CP sends a Conditional Handover indicator to the potential target gNB-DU and to the potential target gNB-CU-UP. This indicator may for example be included in the UE CONTEXT SETUP MESSAGE. An example of a possible implementation is shown below.

_{******************************************************* *******************************}

9.2.2.1 UE CONTEXT SETUP REQUEST

This message is sent by the gNB-CU to request the setup of a UE context.

Direction: gNB-CU ® gNB-DU.

_{******************************************************* *******************************}

In another example embodiment, this indicator may be included in the UE CONTEXT MODIFICATION MESSAGE following a similar formulation as shown in the tabular above. Upon reception of the conditional handover indicator in UE CONTEXT SETUP REQUEST or UE CONTEXT MODIFICATION REQUEST from a potential target gNB-CU-CP, the potential target gNB-DU may take into account that the procedure is used to perform a conditional handover. As a result, the gNB-DU and gNB-CU-UP may take appropriate actions, for example as described above.

In another example, different message(s) (instead of or in addition to an indication IE in an existing message such as the UE Context Setup/Modification Request) may be used e.g. Conditional UE Context Setup/Modification request message, to indicate that this setup/modification request is associated to a CHO instead of e.g. a legacy HO. Therefore, for example, the message(s) may have a type that is specific to or associated with conditional mobility procedures.

The message may also in some examples include a timer value related to the validity of that UE context or pending modification. In other words, for example, the potential target gNB-CU-CP indicates for how long it expects the gNB-DU wait for an incoming UE (and also expects the gNB-DU to release the UE context upon the expiry of the timer). Examples of actions upon reception of such timer are described above.

In another example embodiment, this indicator is included in the BEARER CONTEXT SETUP MESSAGE. An example of a possible implementation is shown below.

_{******************************************************* *******************************}

9.2.2.1 BEARER CONTEXT SETUP REQUEST

This message is sent by the gNB-CU-CP to request the gNB-CU-UP to setup a bearer context.

Direction: gNB-CU-CP ® gNB-CU-UP

_{******************************************************* *******************************}

In another example embodiment, this indicator is included in the BEARER CONTEXT MODIFICATION MESSAGE following a similar formulation as shown in the tabular above.

In some examples, upon reception of the conditional handover indicator in BEARER CONTEXT SETUP REQUEST or BEARER CONTEXT MODIFICATION REQUEST from a potential target gNB-CU-CP, the potential target gNB-CU-UP may take into account that the procedure is used to perform a conditional handover. As a result, the gNB-CU-UP may take appropriate actions, for example as described above.

In another example, different messages (instead of or in addition to an indication) is used e.g. Conditional Bearer Context Setup/Modification request message, to indicate that this setup/modification request is associated to a CHO instead of e.g. a legacy HO. Thus the message(s) may have a type associated with conditional mobility procedures.

The message may for example also include a timer value related to the validity of that bearer context or pending modification. In other words, the potential target gNB-CU-CP indicates for how long it expects the gNB-CU-UP to wait for an incoming UE (and also expects the gNB-CU-UP to release the bearer context upon the expiry of the timer). Examples of actions upon reception of such timer are described above. Figure 9 shows an example of a signaling diagram for an example implementation of a method 900 such as for example as described above .For example, Figure 9 shows an example implementation of conditional handover for inter-node mobility. Step orders may differ in different implementations. In step 1 of the example method 900, measurement control and reports are exchanged between UE and source gNB. In step 2, source gNB makes a conditional handover (CHO) decision. In step 3, source gNB sends CHO REQUEST message to target gNB-CU-CP. In step 4, target gNB-CU-CP sends a BEARER CONTEXT SETUP REQUEST message with CHO indicator to target gNB-CU-UP. In step 5, target gNB-CU-UP replies to target gNB-CU-CP with a BEARER CONTEXT SETUP RESPONSE message, In step 6, target gNB-CU-CP sends UE CONTEXT SETUP REQUEST message with CHO indicator to target gNB-DU. In step 7, target gNB-DU responds to the target gNB-CU-CP with a UE CONTEXT SETUP RESPONSE message. In step 8, target gNB-CU-CP sends a BEARER CONTEXT MODIFICATION REQUEST message to target gNB-CU-UP, and in step 9 target gNB-CU-UP sends a BEARER CONTEXT MODIFICATION RESPONSE message to the target gNB-CU-CP. In step 10, target gNB-CU-CP sends CHO REQUEST ACKNOWLEDGE message to the gource gNB, and in step 1 1 the source gNB and UE exchange RAN CHO Initiation information. In step 12, the UE monitors conditions associated with the CHO, and HO execution is performed in step 13, for example in response to one or more conditions being fulfilled.

In case of intra-gNB-CU-CP handover, in some examples, UE CONTEXT MODIFICATION REQUEST and BEARER CONTEXT MODIFICATION REQUEST messages may be used instead.

Although the subject matter described herein may be implemented in any appropriate type of system using any suitable components, the embodiments disclosed herein are described in relation to a wireless network, such as the example wireless network illustrated in Figure 10. For simplicity, the wireless network of Figure 10 only depicts network QQ106, network nodes QQ160 and QQ160b, and WDs QQ1 10, QQ1 10b, and QQ110c. In practice, a wireless network may further include any additional elements suitable to support communication between wireless devices or between a wireless device and another communication device, such as a landline telephone, a service provider, or any other network node or end device. Of the illustrated components, network node QQ160 and wireless device (WD) QQ1 10 are depicted with additional detail. The wireless network may provide communication and other types of services to one or more wireless devices to facilitate the wireless devices’ access to and/or use of the services provided by, or via, the wireless network. The wireless network may comprise and/or interface with any type of communication, telecommunication, data, cellular, and/or radio network or other similar type of system. In some embodiments, the wireless network may be configured to operate according to specific standards or other types of predefined rules or procedures. Thus, particular embodiments of the wireless network may implement communication standards, such as Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), and/or other suitable 2G, 3G, 4G, or 5G standards; wireless local area network (WLAN) standards, such as the IEEE 802.11 standards; and/or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave and/or ZigBee standards.

Network QQ106 may comprise one or more backhaul networks, core networks, IP networks, public switched telephone networks (PSTNs), packet data networks, optical networks, wide-area networks (WANs), local area networks (LANs), wireless local area networks (WLANs), wired networks, wireless networks, metropolitan area networks, and other networks to enable communication between devices.

Network node QQ160 and WD QQ1 10 comprise various components described in more detail below. These components work together in order to provide network node and/or wireless device functionality, such as providing wireless connections in a wireless network. In different embodiments, the wireless network may comprise any number of wired or wireless networks, network nodes, base stations, controllers, wireless devices, relay stations, and/or any other components or systems that may facilitate or participate in the communication of data and/or signals whether via wired or wireless connections.

As used herein, network node refers to equipment capable, configured, arranged and/or operable to communicate directly or indirectly with a wireless device and/or with other network nodes or equipment in the wireless network to enable and/or provide wireless access to the wireless device and/or to perform other functions (e.g., administration) in the wireless network. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs) and NR NodeBs (gNBs)). Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and may then also be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units and/or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS). Yet further examples of network nodes include multi-standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell/multicast coordination entities (MCEs), core network nodes (e.g., MSCs, MMEs), O&M nodes, OSS nodes, SON nodes, positioning nodes (e.g., E-SMLCs), and/or MDTs. As another example, a network node may be a virtual network node as described in more detail below. More generally, however, network nodes may represent any suitable device (or group of devices) capable, configured, arranged, and/or operable to enable and/or provide a wireless device with access to the wireless network or to provide some service to a wireless device that has accessed the wireless network.

In Figure 10, network node QQ160 includes processing circuitry QQ170, device readable medium QQ180, interface QQ190, auxiliary equipment QQ184, power source QQ186, power circuitry QQ187, and antenna QQ162. Although network node QQ160 illustrated in the example wireless network of Figure 10 may represent a device that includes the illustrated combination of hardware components, other embodiments may comprise network nodes with different combinations of components. It is to be understood that a network node comprises any suitable combination of hardware and/or software needed to perform the tasks, features, functions and methods disclosed herein. Moreover, while the components of network node QQ160 are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, a network node may comprise multiple different physical components that make up a single illustrated component (e.g., device readable medium QQ180 may comprise multiple separate hard drives as well as multiple RAM modules).

Similarly, network node QQ160 may be composed of multiple physically separate components (e.g., a NodeB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which network node QQ160 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeB’s. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, network node QQ160 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate device readable medium QQ180 for the different RATs) and some components may be reused (e.g., the same antenna QQ162 may be shared by the RATs). Network node QQ160 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node QQ160, such as, for example, GSM, WCDMA, LTE, NR, WiFi, or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node QQ160.

Processing circuitry QQ170 is configured to perform any determining, calculating, or similar operations (e.g., certain obtaining operations) described herein as being provided by a network node. These operations performed by processing circuitry QQ170 may include processing information obtained by processing circuitry QQ170 by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and/or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination.

Processing circuitry QQ170 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and/or encoded logic operable to provide, either alone or in conjunction with other network node QQ160 components, such as device readable medium QQ180, network node QQ160 functionality. For example, processing circuitry QQ170 may execute instructions stored in device readable medium QQ180 or in memory within processing circuitry QQ170. Such functionality may include providing any of the various wireless features, functions, or benefits discussed herein. In some embodiments, processing circuitry QQ170 may include a system on a chip (SOC).

In some embodiments, processing circuitry QQ170 may include one or more of radio frequency (RF) transceiver circuitry QQ172 and baseband processing circuitry QQ174. In some embodiments, radio frequency (RF) transceiver circuitry QQ172 and baseband processing circuitry QQ174 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry QQ172 and baseband processing circuitry QQ174 may be on the same chip or set of chips, boards, or units

In certain embodiments, some or all of the functionality described herein as being provided by a network node, base station, eNB or other such network device may be performed by processing circuitry QQ170 executing instructions stored on device readable medium QQ180 or memory within processing circuitry QQ170. In alternative embodiments, some or all of the functionality may be provided by processing circuitry QQ170 without executing instructions stored on a separate or discrete device readable medium, such as in a hard-wired manner. In any of those embodiments, whether executing instructions stored on a device readable storage medium or not, processing circuitry QQ170 can be configured to perform the described functionality. The benefits provided by such functionality are not limited to processing circuitry QQ170 alone or to other components of network node QQ160, but are enjoyed by network node QQ160 as a whole, and/or by end users and the wireless network generally.

Device readable medium QQ180 may comprise any form of volatile or non-volatile computer readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or any other volatile or non-volatile, non-transitory device readable and/or computer- executable memory devices that store information, data, and/or instructions that may be used by processing circuitry 00170. Device readable medium QQ180 may store any suitable instructions, data or information, including a computer program, software, an application including one or more of logic, rules, code, tables, etc. and/or other instructions capable of being executed by processing circuitry QQ170 and, utilized by network node QQ160. Device readable medium QQ180 may be used to store any calculations made by processing circuitry QQ170 and/or any data received via interface QQ190. In some embodiments, processing circuitry QQ170 and device readable medium QQ180 may be considered to be integrated.

Interface QQ190 is used in the wired or wireless communication of signalling and/or data between network node QQ160, network QQ106, and/or WDs QQ1 10. As illustrated, interface QQ190 comprises port(s)/terminal(s) QQ194 to send and receive data, for example to and from network QQ106 over a wired connection. Interface QQ190 also includes radio front end circuitry QQ192 that may be coupled to, or in certain embodiments a part of, antenna QQ162. Radio front end circuitry QQ192 comprises filters QQ198 and amplifiers QQ196. Radio front end circuitry QQ192 may be connected to antenna QQ162 and processing circuitry QQ170. Radio front end circuitry may be configured to condition signals communicated between antenna QQ162 and processing circuitry QQ170. Radio front end circuitry QQ192 may receive digital data that is to be sent out to other network nodes or WDs via a wireless connection. Radio front end circuitry QQ192 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters QQ198 and/or amplifiers QQ196. The radio signal may then be transmitted via antenna QQ162. Similarly, when receiving data, antenna QQ162 may collect radio signals which are then converted into digital data by radio front end circuitry QQ192. The digital data may be passed to processing circuitry QQ170. In other embodiments, the interface may comprise different components and/or different combinations of components.

In certain alternative embodiments, network node QQ160 may not include separate radio front end circuitry QQ192, instead, processing circuitry QQ170 may comprise radio front end circuitry and may be connected to antenna QQ162 without separate radio front end circuitry QQ192. Similarly, in some embodiments, all or some of RF transceiver circuitry QQ172 may be considered a part of interface QQ190. In still other embodiments, interface QQ190 may include one or more ports or terminals QQ194, radio front end circuitry QQ192, and RF transceiver circuitry QQ172, as part of a radio unit (not shown), and interface QQ190 may communicate with baseband processing circuitry QQ174, which is part of a digital unit (not shown).

Antenna QQ162 may include one or more antennas, or antenna arrays, configured to send and/or receive wireless signals. Antenna QQ162 may be coupled to radio front end circuitry QQ190 and may be any type of antenna capable of transmitting and receiving data and/or signals wirelessly. In some embodiments, antenna QQ162 may comprise one or more omni-directional, sector or panel antennas operable to transmit/receive radio signals between, for example, 2 GHz and 66 GHz. An omni-directional antenna may be used to transmit/receive radio signals in any direction, a sector antenna may be used to transmit/receive radio signals from devices within a particular area, and a panel antenna may be a line of sight antenna used to transmit/receive radio signals in a relatively straight line. In some instances, the use of more than one antenna may be referred to as MIMO. In certain embodiments, antenna QQ162 may be separate from network node QQ160 and may be connectable to network node QQ160 through an interface or port.

Antenna QQ162, interface QQ190, and/or processing circuitry QQ170 may be configured to perform any receiving operations and/or certain obtaining operations described herein as being performed by a network node. Any information, data and/or signals may be received from a wireless device, another network node and/or any other network equipment. Similarly, antenna QQ162, interface QQ190, and/or processing circuitry QQ170 may be configured to perform any transmitting operations described herein as being performed by a network node. Any information, data and/or signals may be transmitted to a wireless device, another network node and/or any other network equipment.

Power circuitry QQ187 may comprise, or be coupled to, power management circuitry and is configured to supply the components of network node QQ160 with power for performing the functionality described herein. Power circuitry QQ187 may receive power from power source QQ186. Power source QQ186 and/or power circuitry QQ187 may be configured to provide power to the various components of network node QQ160 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). Power source QQ186 may either be included in, or external to, power circuitry QQ187 and/or network node QQ160. For example, network node QQ160 may be connectable to an external power source (e.g., an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry QQ187. As a further example, power source QQ186 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry QQ187. The battery may provide backup power should the external power source fail. Other types of power sources, such as photovoltaic devices, may also be used.

Alternative embodiments of network node QQ160 may include additional components beyond those shown in Figure 10 that may be responsible for providing certain aspects of the network node’s functionality, including any of the functionality described herein and/or any functionality necessary to support the subject matter described herein. For example, network node QQ160 may include user interface equipment to allow input of information into network node QQ160 and to allow output of information from network node QQ160. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for network node QQ160.

As used herein, wireless device (WD) refers to a device capable, configured, arranged and/or operable to communicate wirelessly with network nodes and/or other wireless devices. Unless otherwise noted, the term WD may be used interchangeably herein with user equipment (UE). Communicating wirelessly may involve transmitting and/or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and/or other types of signals suitable for conveying information through air. In some embodiments, a WD may be configured to transmit and/or receive information without direct human interaction. For instance, a WD may be designed to transmit information to a network on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the network. Examples of a WD include, but are not limited to, a smart phone, a mobile phone, a cell phone, a voice over IP (VoIP) phone, a wireless local loop phone, a desktop computer, a personal digital assistant (PDA), a wireless cameras, a gaming console or device, a music storage device, a playback appliance, a wearable terminal device, a wireless endpoint, a mobile station, a tablet, a laptop, a laptop-embedded equipment (LEE), a laptop-mounted equipment (LME), a smart device, a wireless customer-premise equipment (CPE) a vehicle- mounted wireless terminal device, etc.. A WD may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-everything (V2X) and may in this case be referred to as a D2D communication device. As yet another specific example, in an Internet of Things (loT) scenario, a WD may represent a machine or other device that performs monitoring and/or measurements, and transmits the results of such monitoring and/or measurements to another WD and/or a network node. The WD may in this case be a machine-to-machine (M2M) device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the WD may be a UE implementing the 3GPP narrow band internet of things (NB-loT) standard. Particular examples of such machines or devices are sensors, metering devices such as power meters, industrial machinery, or home or personal appliances (e.g. refrigerators, televisions, etc.) personal wearables (e.g., watches, fitness trackers, etc.). In other scenarios, a WD may represent a vehicle or other equipment that is capable of monitoring and/or reporting on its operational status or other functions associated with its operation. A WD as described above may represent the endpoint of a wireless connection, in which case the device may be referred to as a wireless terminal. Furthermore, a WD as described above may be mobile, in which case it may also be referred to as a mobile device or a mobile terminal.

As illustrated, wireless device QQ1 10 includes antenna QQ11 1 , interface QQ114, processing circuitry QQ120, device readable medium QQ130, user interface equipment QQ132, auxiliary equipment QQ134, power source QQ136 and power circuitry QQ137. WD QQ110 may include multiple sets of one or more of the illustrated components for different wireless technologies supported by WD QQ1 10, such as, for example, GSM, WCDMA, LTE, NR, WiFi, WiMAX, or Bluetooth wireless technologies, just to mention a few. These wireless technologies may be integrated into the same or different chips or set of chips as other components within WD QQ1 10.

Antenna QQ11 1 may include one or more antennas or antenna arrays, configured to send and/or receive wireless signals, and is connected to interface QQ114. In certain alternative embodiments, antenna QQ11 1 may be separate from WD QQ1 10 and be connectable to WD QQ110 through an interface or port. Antenna QQ1 1 1 , interface QQ114, and/or processing circuitry QQ120 may be configured to perform any receiving or transmitting operations described herein as being performed by a WD. Any information, data and/or signals may be received from a network node and/or another WD. In some embodiments, radio front end circuitry and/or antenna QQ11 1 may be considered an interface. As illustrated, interface QQ114 comprises radio front end circuitry QQ1 12 and antenna QQ11 1. Radio front end circuitry QQ112 comprise one or more filters QQ118 and amplifiers QQ116. Radio front end circuitry QQ1 14 is connected to antenna QQ11 1 and processing circuitry QQ120, and is configured to condition signals communicated between antenna QQ11 1 and processing circuitry QQ120. Radio front end circuitry QQ112 may be coupled to or a part of antenna QQ1 11. In some embodiments, WD QQ1 10 may not include separate radio front end circuitry QQ1 12; rather, processing circuitry QQ120 may comprise radio front end circuitry and may be connected to antenna QQ11 1. Similarly, in some embodiments, some or all of RF transceiver circuitry QQ122 may be considered a part of interface QQ1 14. Radio front end circuitry QQ112 may receive digital data that is to be sent out to other network nodes or WDs via a wireless connection. Radio front end circuitry QQ1 12 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters QQ1 18 and/or amplifiers QQ1 16. The radio signal may then be transmitted via antenna QQ1 11. Similarly, when receiving data, antenna QQ1 11 may collect radio signals which are then converted into digital data by radio front end circuitry QQ112. The digital data may be passed to processing circuitry QQ120. In other embodiments, the interface may comprise different components and/or different combinations of components.

Processing circuitry QQ120 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software, and/or encoded logic operable to provide, either alone or in conjunction with other WD QQ1 10 components, such as device readable medium QQ130, WD QQ110 functionality. Such functionality may include providing any of the various wireless features or benefits discussed herein. For example, processing circuitry QQ120 may execute instructions stored in device readable medium QQ130 or in memory within processing circuitry QQ120 to provide the functionality disclosed herein.

As illustrated, processing circuitry QQ120 includes one or more of RF transceiver circuitry QQ122, baseband processing circuitry QQ124, and application processing circuitry QQ126. In other embodiments, the processing circuitry may comprise different components and/or different combinations of components. In certain embodiments processing circuitry QQ120 of WD QQ1 10 may comprise a SOC. In some embodiments, RF transceiver circuitry QQ122, baseband processing circuitry QQ124, and application processing circuitry QQ126 may be on separate chips or sets of chips. In alternative embodiments, part or all of baseband processing circuitry QQ124 and application processing circuitry QQ126 may be combined into one chip or set of chips, and RF transceiver circuitry QQ122 may be on a separate chip or set of chips. In still alternative embodiments, part or all of RF transceiver circuitry QQ122 and baseband processing circuitry QQ124 may be on the same chip or set of chips, and application processing circuitry QQ126 may be on a separate chip or set of chips. In yet other alternative embodiments, part or all of RF transceiver circuitry QQ122, baseband processing circuitry QQ124, and application processing circuitry QQ126 may be combined in the same chip or set of chips. In some embodiments, RF transceiver circuitry QQ122 may be a part of interface QQ114. RF transceiver circuitry QQ122 may condition RF signals for processing circuitry QQ120.

In certain embodiments, some or all of the functionality described herein as being performed by a WD may be provided by processing circuitry QQ120 executing instructions stored on device readable medium QQ130, which in certain embodiments may be a computer- readable storage medium. In alternative embodiments, some or all of the functionality may be provided by processing circuitry QQ120 without executing instructions stored on a separate or discrete device readable storage medium, such as in a hard-wired manner. In any of those particular embodiments, whether executing instructions stored on a device readable storage medium or not, processing circuitry QQ120 can be configured to perform the described functionality. The benefits provided by such functionality are not limited to processing circuitry QQ120 alone or to other components of WD QQ1 10, but are enjoyed by WD QQ1 10 as a whole, and/or by end users and the wireless network generally.

Processing circuitry QQ120 may be configured to perform any determining, calculating, or similar operations (e.g., certain obtaining operations) described herein as being performed by a WD. These operations, as performed by processing circuitry QQ120, may include processing information obtained by processing circuitry QQ120 by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored by WD QQ110, and/or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination.

Device readable medium QQ130 may be operable to store a computer program, software, an application including one or more of logic, rules, code, tables, etc. and/or other instructions capable of being executed by processing circuitry QQ120. Device readable medium QQ130 may include computer memory (e.g., Random Access Memory (RAM) or Read Only Memory (ROM)), mass storage media (e.g., a hard disk), removable storage media (e.g., a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or any other volatile or non volatile, non-transitory device readable and/or computer executable memory devices that store information, data, and/or instructions that may be used by processing circuitry QQ120. In some embodiments, processing circuitry QQ120 and device readable medium QQ130 may be considered to be integrated.

User interface equipment QQ132 may provide components that allow for a human user to interact with WD QQ1 10. Such interaction may be of many forms, such as visual, audial, tactile, etc. User interface equipment QQ132 may be operable to produce output to the user and to allow the user to provide input to WD QQ1 10. The type of interaction may vary depending on the type of user interface equipment QQ132 installed in WD QQ1 10. For example, if WD QQ110 is a smart phone, the interaction may be via a touch screen; if WD QQ110 is a smart meter, the interaction may be through a screen that provides usage (e.g., the number of gallons used) or a speaker that provides an audible alert (e.g., if smoke is detected). User interface equipment QQ132 may include input interfaces, devices and circuits, and output interfaces, devices and circuits. User interface equipment QQ132 is configured to allow input of information into WD QQ1 10, and is connected to processing circuitry QQ120 to allow processing circuitry QQ120 to process the input information. User interface equipment QQ132 may include, for example, a microphone, a proximity or other sensor, keys/buttons, a touch display, one or more cameras, a USB port, or other input circuitry. User interface equipment QQ132 is also configured to allow output of information from WD QQ1 10, and to allow processing circuitry QQ120 to output information from WD QQ110. User interface equipment QQ132 may include, for example, a speaker, a display, vibrating circuitry, a USB port, a headphone interface, or other output circuitry. Using one or more input and output interfaces, devices, and circuits, of user interface equipment QQ132, WD QQ110 may communicate with end users and/or the wireless network, and allow them to benefit from the functionality described herein.

Auxiliary equipment QQ134 is operable to provide more specific functionality which may not be generally performed by WDs. This may comprise specialized sensors for doing measurements for various purposes, interfaces for additional types of communication such as wired communications etc. The inclusion and type of components of auxiliary equipment QQ134 may vary depending on the embodiment and/or scenario.

Power source QQ136 may, in some embodiments, be in the form of a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic devices or power cells, may also be used. WD QQ110 may further comprise power circuitry QQ137 for delivering power from power source QQ136 to the various parts of WD QQ1 10 which need power from power source QQ136 to carry out any functionality described or indicated herein. Power circuitry QQ137 may in certain embodiments comprise power management circuitry. Power circuitry QQ137 may additionally or alternatively be operable to receive power from an external power source; in which case WD QQ110 may be connectable to the external power source (such as an electricity outlet) via input circuitry or an interface such as an electrical power cable. Power circuitry QQ137 may also in certain embodiments be operable to deliver power from an external power source to power source QQ136. This may be, for example, for the charging of power source QQ136. Power circuitry QQ137 may perform any formatting, converting, or other modification to the power from power source QQ136 to make the power suitable for the respective components of WD QQ110 to which power is supplied.

Figure 1 1 illustrates one embodiment of a UE in accordance with various aspects described herein. As used herein, a user equipment or UE may not necessarily have a user in the sense of a human user who owns and/or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter). UE QQ2200 may be any UE identified by the 3 ^rd Generation Partnership Project (3GPP), including a NB-loT UE, a machine type communication (MTC) UE, and/or an enhanced MTC (eMTC) UE. UE QQ200, as illustrated in Figure 11 , is one example of a WD configured for communication in accordance with one or more communication standards promulgated by the 3 ^rd Generation Partnership Project (3GPP), such as 3GPP’s GSM, UMTS, LTE, and/or 5G standards. As mentioned previously, the term WD and UE may be used interchangeable. Accordingly, although Figure 11 is a UE, the components discussed herein are equally applicable to a WD, and vice-versa.

In Figure 11 , UE QQ200 includes processing circuitry QQ201 that is operatively coupled to input/output interface QQ205, radio frequency (RF) interface QQ209, network connection interface QQ21 1 , memory QQ215 including random access memory (RAM) QQ217, read-only memory (ROM) QQ219, and storage medium QQ221 or the like, communication subsystem QQ231 , power source QQ233, and/or any other component, or any combination thereof. Storage medium QQ221 includes operating system QQ223, application program QQ225, and data QQ227. In other embodiments, storage medium QQ221 may include other similar types of information. Certain UEs may utilize all of the components shown in Figure 11 , or only a subset of the components. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

In Figure 1 1 , processing circuitry QQ201 may be configured to process computer instructions and data. Processing circuitry QQ201 may be configured to implement any sequential state machine operative to execute machine instructions stored as machine- readable computer programs in the memory, such as one or more hardware-implemented state machines (e.g., in discrete logic, FPGA, ASIC, etc.); programmable logic together with appropriate firmware; one or more stored program, general-purpose processors, such as a microprocessor or Digital Signal Processor (DSP), together with appropriate software; or any combination of the above. For example, the processing circuitry QQ201 may include two central processing units (CPUs). Data may be information in a form suitable for use by a computer.

In the depicted embodiment, input/output interface QQ205 may be configured to provide a communication interface to an input device, output device, or input and output device. UE QQ200 may be configured to use an output device via input/output interface QQ205. An output device may use the same type of interface port as an input device. For example, a USB port may be used to provide input to and output from UE QQ200. The output device may be a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. UE QQ200 may be configured to use an input device via input/output interface QQ205 to allow a user to capture information into UE QQ200. The input device may include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, another like sensor, or any combination thereof. For example, the input device may be an accelerometer, a magnetometer, a digital camera, a microphone, and an optical sensor.

In Figure 11 , RF interface QQ209 may be configured to provide a communication interface to RF components such as a transmitter, a receiver, and an antenna. Network connection interface QQ211 may be configured to provide a communication interface to network QQ243a. Network QQ243a may encompass wired and/or wireless networks such as a local-area network (LAN), a wide-area network (WAN), a computer network, a wireless network, a telecommunications network, another like network or any combination thereof. For example, network QQ243a may comprise a Wi-Fi network. Network connection interface QQ21 1 may be configured to include a receiver and a transmitter interface used to communicate with one or more other devices over a communication network according to one or more communication protocols, such as Ethernet, TCP/IP, SONET, ATM, or the like. Network connection interface QQ211 may implement receiver and transmitter functionality appropriate to the communication network links (e.g., optical, electrical, and the like). The transmitter and receiver functions may share circuit components, software or firmware, or alternatively may be implemented separately.

RAM QQ217 may be configured to interface via bus QQ202 to processing circuitry QQ201 to provide storage or caching of data or computer instructions during the execution of software programs such as the operating system, application programs, and device drivers. ROM QQ219 may be configured to provide computer instructions or data to processing circuitry QQ201. For example, ROM QQ219 may be configured to store invariant low-level system code or data for basic system functions such as basic input and output (I/O), startup, or reception of keystrokes from a keyboard that are stored in a non-volatile memory. Storage medium QQ221 may be configured to include memory such as RAM, ROM, programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, floppy disks, hard disks, removable cartridges, or flash drives. In one example, storage medium QQ221 may be configured to include operating system QQ223, application program QQ225 such as a web browser application, a widget or gadget engine or another application, and data file QQ227. Storage medium QQ221 may store, for use by UE QQ200, any of a variety of various operating systems or combinations of operating systems.

Storage medium QQ221 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), floppy disk drive, flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro- DIMM SDRAM, smartcard memory such as a subscriber identity module or a removable user identity (SIM/RUIM) module, other memory, or any combination thereof. Storage medium QQ221 may allow UE QQ200 to access computer-executable instructions, application programs or the like, stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied in storage medium QQ221 , which may comprise a device readable medium.

In Figure 11 , processing circuitry QQ201 may be configured to communicate with network QQ243b using communication subsystem QQ231. Network QQ243a and network QQ243b may be the same network or networks or different network or networks. Communication subsystem QQ231 may be configured to include one or more transceivers used to communicate with network QQ243b. For example, communication subsystem QQ231 may be configured to include one or more transceivers used to communicate with one or more remote transceivers of another device capable of wireless communication such as another WD, UE, or base station of a radio access network (RAN) according to one or more communication protocols, such as IEEE 802.1 1 , CDMA, WCDMA, GSM, LTE, UTRAN, WiMax, or the like. Each transceiver may include transmitter QQ233 and/or receiver QQ235 to implement transmitter or receiver functionality, respectively, appropriate to the RAN links (e.g., frequency allocations and the like). Further, transmitter QQ233 and receiver QQ235 of each transceiver may share circuit components, software or firmware, or alternatively may be implemented separately.

In the illustrated embodiment, the communication functions of communication subsystem QQ231 may include data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. For example, communication subsystem QQ231 may include cellular communication, Wi-Fi communication, Bluetooth communication, and GPS communication. Network QQ243b may encompass wired and/or wireless networks such as a local-area network (LAN), a wide-area network (WAN), a computer network, a wireless network, a telecommunications network, another like network or any combination thereof. For example, network QQ243b may be a cellular network, a Wi-Fi network, and/or a near-field network. Power source QQ213 may be configured to provide alternating current (AC) or direct current (DC) power to components of UE QQ200.

The features, benefits and/or functions described herein may be implemented in one of the components of UE QQ200 or partitioned across multiple components of UE QQ200. Further, the features, benefits, and/or functions described herein may be implemented in any combination of hardware, software or firmware. In one example, communication subsystem QQ231 may be configured to include any of the components described herein. Further, processing circuitry QQ201 may be configured to communicate with any of such components over bus QQ202. In another example, any of such components may be represented by program instructions stored in memory that when executed by processing circuitry QQ201 perform the corresponding functions described herein. In another example, the functionality of any of such components may be partitioned between processing circuitry QQ201 and communication subsystem QQ231. In another example, the non-computationally intensive functions of any of such components may be implemented in software or firmware and the computationally intensive functions may be implemented in hardware.

Figure 12 is a schematic block diagram illustrating a virtualization environment QQ300 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to a node (e.g., a virtualized base station or a virtualized radio access node) or to a device (e.g., a UE, a wireless device or any other type of communication device) or components thereof and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components (e.g., via one or more applications, components, functions, virtual machines or containers executing on one or more physical processing nodes in one or more networks).

In some embodiments, some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines implemented in one or more virtual environments QQ300 hosted by one or more of hardware nodes QQ330. Further, in embodiments in which the virtual node is not a radio access node or does not require radio connectivity (e.g., a core network node), then the network node may be entirely virtualized.

The functions may be implemented by one or more applications QQ320 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) operative to implement some of the features, functions, and/or benefits of some of the embodiments disclosed herein. Applications QQ320 are run in virtualization environment QQ300 which provides hardware QQ330 comprising processing circuitry QQ360 and memory QQ390. Memory QQ390 contains instructions QQ395 executable by processing circuitry QQ360 whereby application QQ320 is operative to provide one or more of the features, benefits, and/or functions disclosed herein.

Virtualization environment QQ300, comprises general-purpose or special-purpose network hardware devices QQ330 comprising a set of one or more processors or processing circuitry QQ360, which may be commercial off-the-shelf (COTS) processors, dedicated Application Specific Integrated Circuits (ASICs), or any other type of processing circuitry including digital or analog hardware components or special purpose processors. Each hardware device may comprise memory QQ390-1 which may be non-persistent memory for temporarily storing instructions QQ395 or software executed by processing circuitry QQ360. Each hardware device may comprise one or more network interface controllers (NICs) QQ370, also known as network interface cards, which include physical network interface QQ380. Each hardware device may also include non-transitory, persistent, machine-readable storage media QQ390-2 having stored therein software QQ395 and/or instructions executable by processing circuitry QQ360. Software QQ395 may include any type of software including software for instantiating one or more virtualization layers QQ350 (also referred to as hypervisors), software to execute virtual machines QQ340 as well as software allowing it to execute functions, features and/or benefits described in relation with some embodiments described herein.

Virtual machines QQ340, comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer QQ350 or hypervisor. Different embodiments of the instance of virtual appliance QQ320 may be implemented on one or more of virtual machines QQ340, and the implementations may be made in different ways.

During operation, processing circuitry QQ360 executes software QQ395 to instantiate the hypervisor or virtualization layer QQ350, which may sometimes be referred to as a virtual machine monitor (VMM). Virtualization layer QQ350 may present a virtual operating platform that appears like networking hardware to virtual machine QQ340.

As shown in Figure 12, hardware QQ330 may be a standalone network node with generic or specific components. Hardware QQ330 may comprise antenna QQ3225 and may implement some functions via virtualization. Alternatively, hardware QQ330 may be part of a larger cluster of hardware (e.g. such as in a data center or customer premise equipment (CPE)) where many hardware nodes work together and are managed via management and orchestration (MANO) QQ3100, which, among others, oversees lifecycle management of applications QQ320.

Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

In the context of NFV, virtual machine QQ340 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each of virtual machines QQ340, and that part of hardware QQ330 that executes that virtual machine, be it hardware dedicated to that virtual machine and/or hardware shared by that virtual machine with others of the virtual machines QQ340, forms a separate virtual network elements (VNE).

Still in the context of NFV, Virtual Network Function (VNF) is responsible for handling specific network functions that run in one or more virtual machines QQ340 on top of hardware networking infrastructure QQ330 and corresponds to application QQ320 in Figure 12.

In some embodiments, one or more radio units QQ3200 that each include one or more transmitters QQ3220 and one or more receivers QQ3210 may be coupled to one or more antennas QQ3225. Radio units QQ3200 may communicate directly with hardware nodes QQ330 via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station.

In some embodiments, some signalling can be effected with the use of control system QQ3230 which may alternatively be used for communication between the hardware nodes QQ330 and radio units QQ3200.

With reference to FIGURE 13, in accordance with an embodiment, a communication system includes telecommunication network QQ410, such as a 3GPP-type cellular network, which comprises access network QQ41 1 , such as a radio access network, and core network QQ414. Access network QQ411 comprises a plurality of base stations QQ412a, QQ412b, QQ412c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area QQ413a, QQ413b, QQ413c. Each base station QQ412a, QQ412b, QQ412c is connectable to core network QQ414 over a wired or wireless connection QQ415. A first UE QQ491 located in coverage area QQ413c is configured to wirelessly connect to, or be paged by, the corresponding base station QQ412c. A second UE QQ492 in coverage area QQ413a is wirelessly connectable to the corresponding base station QQ412a. While a plurality of UEs QQ491 , QQ492 are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole UE is connecting to the corresponding base station QQ412.

Telecommunication network QQ410 is itself connected to host computer QQ430, which may be embodied in the hardware and/or software of a standalone server, a cloud- implemented server, a distributed server or as processing resources in a server farm. Host computer QQ430 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. Connections QQ421 and QQ422 between telecommunication network QQ410 and host computer QQ430 may extend directly from core network QQ414 to host computer QQ430 or may go via an optional intermediate network QQ420. Intermediate network QQ420 may be one of, or a combination of more than one of, a public, private or hosted network; intermediate network QQ420, if any, may be a backbone network or the Internet; in particular, intermediate network QQ420 may comprise two or more sub-networks (not shown).

The communication system of Figure 13 as a whole enables connectivity between the connected UEs QQ491 , QQ492 and host computer QQ430. The connectivity may be described as an over-the-top (OTT) connection QQ450. Host computer QQ430 and the connected UEs QQ491 , QQ492 are configured to communicate data and/or signaling via OTT connection QQ450, using access network QQ41 1 , core network QQ414, any intermediate network QQ420 and possible further infrastructure (not shown) as intermediaries. OTT connection QQ450 may be transparent in the sense that the participating communication devices through which OTT connection QQ450 passes are unaware of routing of uplink and downlink communications. For example, base station QQ412 may not or need not be informed about the past routing of an incoming downlink communication with data originating from host computer QQ430 to be forwarded (e.g., handed over) to a connected UE QQ491. Similarly, base station QQ412 need not be aware of the future routing of an outgoing uplink communication originating from the UE QQ491 towards the host computer QQ430.

Example implementations, in accordance with an embodiment, of the UE, base station and host computer discussed in the preceding paragraphs will now be described with reference to Figure 14. In communication system QQ500, host computer QQ510 comprises hardware QQ515 including communication interface QQ516 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of communication system QQ500. Host computer QQ510 further comprises processing circuitry QQ518, which may have storage and/or processing capabilities. In particular, processing circuitry QQ518 may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. Host computer QQ510 further comprises software QQ511 , which is stored in or accessible by host computer QQ510 and executable by processing circuitry QQ518. Software QQ511 includes host application QQ512. Host application QQ512 may be operable to provide a service to a remote user, such as UE QQ530 connecting via OTT connection QQ550 terminating at UE QQ530 and host computer QQ510. In providing the service to the remote user, host application QQ512 may provide user data which is transmitted using OTT connection QQ550. Communication system QQ500 further includes base station QQ520 provided in a telecommunication system and comprising hardware QQ525 enabling it to communicate with host computer QQ510 and with UE QQ530. Hardware QQ525 may include communication interface QQ526 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of communication system QQ500, as well as radio interface QQ527 for setting up and maintaining at least wireless connection QQ570 with UE QQ530 located in a coverage area (not shown in Figure 14) served by base station QQ520. Communication interface QQ526 may be configured to facilitate connection QQ560 to host computer QQ510. Connection QQ560 may be direct or it may pass through a core network (not shown in Figure 14) of the telecommunication system and/or through one or more intermediate networks outside the telecommunication system. In the embodiment shown, hardware QQ525 of base station QQ520 further includes processing circuitry QQ528, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. Base station QQ520 further has software QQ521 stored internally or accessible via an external connection.

Communication system QQ500 further includes UE QQ530 already referred to. Its hardware QQ535 may include radio interface QQ537 configured to set up and maintain wireless connection QQ570 with a base station serving a coverage area in which UE QQ530 is currently located. Hardware QQ535 of UE QQ530 further includes processing circuitry QQ538, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. UE QQ530 further comprises software QQ531 , which is stored in or accessible by UE QQ530 and executable by processing circuitry QQ538. Software QQ531 includes client application QQ532. Client application QQ532 may be operable to provide a service to a human or non-human user via UE QQ530, with the support of host computer QQ510. In host computer QQ510, an executing host application QQ512 may communicate with the executing client application QQ532 via OTT connection QQ550 terminating at UE QQ530 and host computer QQ510. In providing the service to the user, client application QQ532 may receive request data from host application QQ512 and provide user data in response to the request data. OTT connection QQ550 may transfer both the request data and the user data. Client application QQ532 may interact with the user to generate the user data that it provides.

It is noted that host computer QQ510, base station QQ520 and UE QQ530 illustrated in Figure 14 may be similar or identical to host computer QQ430, one of base stations QQ412a, QQ412b, QQ412c and one of UEs QQ491 , QQ492 of Figure 13, respectively. This is to say, the inner workings of these entities may be as shown in Figure 14 and independently, the surrounding network topology may be that of Figure 13.

In Figure 14, OTT connection QQ550 has been drawn abstractly to illustrate the communication between host computer QQ510 and UE QQ530 via base station QQ520, without explicit reference to any intermediary devices and the precise routing of messages via these devices. Network infrastructure may determine the routing, which it may be configured to hide from UE QQ530 or from the service provider operating host computer QQ510, or both. While OTT connection QQ550 is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of load balancing consideration or reconfiguration of the network).

Wireless connection QQ570 between UE QQ530 and base station QQ520 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to UE QQ530 using OTT connection QQ550, in which wireless connection QQ570 forms the last segment. More precisely, the teachings of these embodiments may improve the signaling efficiency and thereby provide benefits such as improved battery life, improved network efficiency etc.

A measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring OTT connection QQ550 between host computer QQ510 and UE QQ530, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring OTT connection QQ550 may be implemented in software QQ511 and hardware QQ515 of host computer QQ510 or in software QQ531 and hardware QQ535 of UE QQ530, or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which OTT connection QQ550 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software QQ51 1 , QQ531 may compute or estimate the monitored quantities. The reconfiguring of OTT connection QQ550 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect base station QQ520, and it may be unknown or imperceptible to base station QQ520. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating host computer QQ510’s measurements of throughput, propagation times, latency and the like. The measurements may be implemented in that software QQ511 and QQ531 causes messages to be transmitted, in particular empty or‘dummy’ messages, using OTT connection QQ550 while it monitors propagation times, errors etc.

Figure 15 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figures 13 and 14. For simplicity of the present disclosure, only drawing references to Figure 15 will be included in this section. In step QQ610, the host computer provides user data. In substep QQ611 (which may be optional) of step QQ610, the host computer provides the user data by executing a host application. In step QQ620, the host computer initiates a transmission carrying the user data to the UE. In step QQ630 (which may be optional), the base station transmits to the UE the user data which was carried in the transmission that the host computer initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step QQ640 (which may also be optional), the UE executes a client application associated with the host application executed by the host computer.

Figure 16 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figures 13 and 14. For simplicity of the present disclosure, only drawing references to Figure 16 will be included in this section. In step QQ710 of the method, the host computer provides user data. In an optional substep (not shown) the host computer provides the user data by executing a host application. In step QQ720, the host computer initiates a transmission carrying the user data to the UE. The transmission may pass via the base station, in accordance with the teachings of the embodiments described throughout this disclosure. In step QQ730 (which may be optional), the UE receives the user data carried in the transmission.

Figure 17 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figures 13 and 14. For simplicity of the present disclosure, only drawing references to Figure 17 will be included in this section. In step QQ810 (which may be optional), the UE receives input data provided by the host computer. Additionally or alternatively, in step QQ820, the UE provides user data. In substep QQ821 (which may be optional) of step QQ820, the UE provides the user data by executing a client application. In substep QQ811 (which may be optional) of step QQ810, the UE executes a client application which provides the user data in reaction to the received input data provided by the host computer. In providing the user data, the executed client application may further consider user input received from the user. Regardless of the specific manner in which the user data was provided, the UE initiates, in substep QQ830 (which may be optional), transmission of the user data to the host computer. In step QQ840 of the method, the host computer receives the user data transmitted from the UE, in accordance with the teachings of the embodiments described throughout this disclosure.

Figure 18 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figures 13 and 14. For simplicity of the present disclosure, only drawing references to Figure 18 will be included in this section. In step QQ910 (which may be optional), in accordance with the teachings of the embodiments described throughout this disclosure, the base station receives user data from the UE. In step QQ920 (which may be optional), the base station initiates transmission of the received user data to the host computer. In step QQ930 (which may be optional), the host computer receives the user data carried in the transmission initiated by the base station.

Figure 19 illustrates a schematic block diagram of an apparatus WW00 in a wireless network (for example, the wireless network shown in Figure 10). The apparatus may be implemented in a wireless device or network node (e.g., wireless device QQ110 or network node QQ160 shown in Figure 10). Apparatus WW00 is operable to carry out the example method described with reference to Figure 7 or 8 and possibly any other processes or methods disclosed herein. It is also to be understood that the method of Figure 7 or 8 is not necessarily carried out solely by apparatus WW00. At least some operations of the method can be performed by one or more other entities.

Virtual Apparatus WW00 may comprise processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include digital signal processors (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as read-only memory (ROM), random-access memory, cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein, in several embodiments. In some implementations, the processing circuitry may be used to cause receiver unit WW02, modifier unit WW04, and any other suitable units of apparatus WW00 to perform corresponding functions according one or more embodiments of the present disclosure. Virtual apparatus WWOO may be configured with a list of at least one configuration, each of the at least one configuration associated with a respective conditional mobility procedure and a respective potential target cell.

As illustrated in Figure WW, apparatus WWOO includes sending unit WW02 that is configured to send a message to a base station to prepare the base station for a mobility procedure by a User Equipment (UE) to a target cell associated with the base station, wherein the message indicates that the mobility procedure is associated with a condition.

The term unit may have conventional meaning in the field of electronics, electrical devices and/or electronic devices and may include, for example, electrical and/or electronic circuitry, devices, modules, processors, memories, logic solid state and/or discrete devices, computer programs or instructions for carrying out respective tasks, procedures, computations, outputs, and/or displaying functions, and so on, as such as those that are described herein.

Group A Embodiments

1. A method in a network node, the method comprising:

sending a message to a base station to prepare the base station for a mobility procedure by a User Equipment (UE) to a target cell associated with the base station, wherein the message indicates that the mobility procedure is associated with a condition.

2. The method of embodiment 1 , wherein the message indicates that the UE will carry out the mobility procedure upon determining that the condition has been met.

3. The method of embodiment 1 or 2, wherein the message contains an indication that indicates that the mobility procedure is associated with the condition.

4. The method of any of the preceding embodiments, wherein the message has a type that is associated with mobility procedures that are associated with conditions.

5. The method of any of the preceding embodiments, wherein the message further indicates that the preparation for the mobility procedure by the base station is associated with an expiry timer.

6. The method of embodiment 5, wherein the message further identifies a value for the expiry timer.

7. The method of any of the preceding embodiments, comprising determining that the UE has carried out the mobility procedure.

8. The method of embodiment 7, wherein determining that the UE has carried out the mobility procedure comprises receiving a RRCReconfigurationComplete message from the base station. 9. The method of embodiment 7 or 8, comprising, after determining that the UE has carried out the mobility procedure, causing each of at least one further base station to release resources reserved in a respective further target cell for the UE for a respective further mobility procedure associated with a respective further condition.

10. The method of any of the preceding embodiments, wherein the base station

comprises a gNB-DU, gNB-CU-UP or eNB-DU.

11. The method of any of the preceding embodiments, wherein the network node

comprises a gNB-CU, gNB-CU-CP or eNB-CU.

12. The method of any of embodiments 1 to 8, wherein the base station and each of at least one further base station each comprise a respective gNB-DU or eNB-DU, the network node comprises a gNB-CU-CP, gNB-CU or eNB-CU, the network node comprises a plurality of modules, each module associated with a respective one of the base station and the at least one further base station, and the method comprises: reserving, in each module, resources for the UE, the resources associated with the respective one of the base and the at least one further base station, and/or the resources associated with a cell associated with the respective one of the base station and the at least one further base station; and

after determining that the UE has carried out the mobility procedure, causing at least one of the modules to release the respective resources.

13. The method of any of the preceding embodiments, wherein the message comprises a message to set up or modify a UE context and/or a bearer context for the mobility procedure.

14. The method of embodiment 13, wherein the message comprises a UE Context Setup Request message, a UE Context Modification Request message, a Bearer Context Setup Request message or a Bearer Context Modification Request message.

15. The method of any of the preceding embodiments, wherein sending the message comprises sending the message over at least a W1 interface, F1 interface and/or an E1 interface.

16. The method of any of the preceding embodiments, wherein the mobility procedure comprises a conditional handover, conditional resume, conditional reconfiguration with sync, conditional reconfiguration or conditional reestablishment procedure.

17. The method of any of the preceding embodiments, wherein the condition comprises whether a signal strength of the target cell associated with the base station is greater than a signal strength of a serving cell of the UE by a first threshold, and/or whether the signal strength of the target cell is greater than a signal strength threshold.

18. The method of any of the previous embodiments, further comprising: - providing user data; and

- forwarding the user data to a host computer via the transmission to the base station.

19. A method in base station, the method comprising:

receiving a message from a network node to prepare the base station for a mobility procedure by a User Equipment (UE) to a target cell associated with the base station, wherein the message indicates that the mobility procedure is associated with a condition.

20. The method of embodiment 19, comprising reserving resources for the UE in the target cell based on the indication that the mobility procedure is associated with a condition.

21. The method of embodiment 19 or 20, wherein the message further indicates that the UE will carry out the mobility procedure upon determining that the condition has been met.

22. The method of any of embodiments 19 to 21 , wherein the message contains an

indication that indicates that the mobility procedure is associated with the condition.

23. The method of any of embodiments 19 to 22, wherein the message has a type that is associated with mobility procedures that are associated with conditions.

24. The method of any of embodiments 19 to 23, wherein the message further indicates that the preparation for the mobility procedure by the base station is associated with an expiry timer.

25. The method of embodiment 24, wherein the message further identifies a value for the expiry timer.

26. The method of embodiment 24 or 25, comprising starting the expiry timer upon

receipt of the message and/or upon reserving resources for the UE in the target cell.

27. The method of embodiment 26, comprising releasing resources reserved for the UE in the target cell upon expiry of the expiry timer.

28. The method of any of embodiments 19 to 27, comprising determining that the UE has carried out the mobility procedure.

29. The method of embodiment 28, wherein determining that the UE has carried out the mobility procedure comprises detecting receipt of a contention free random-access resource, a preamble and/or a C-RNTI from the UE.

30. The method of embodiment 28 or 29, comprising, after determining that the UE has carried out the mobility procedure, causing each of at least one further base station to release resources reserved in a respective further target cell for the UE for a respective further mobility procedure associated with a respective further condition. 31. The method of embodiment 30, wherein causing each of at least one further base station to release resources comprises sending a RRCReconfigurationComplete message to the network node.

32. The method of any of embodiments 19 to 31 , wherein the message comprises a message to set up or modify a UE context and/or a bearer context for the mobility procedure.

33. The method of embodiment 32, wherein the message comprises a UE Context Setup Request message, a UE Context Modification Request message, a Bearer Context Setup Request message or a Bearer Context Modification Request message.

34. The method of any of embodiments 19 to 33, wherein receiving the message

comprises receiving the message over at least a W1 interface, F1 interface and/or an E1 interface.

35. The method of any of embodiments 19 to 34, wherein the base station comprises a gNB-DU, gNB-CU-UP or eNB-DU.

36. The method of any of embodiments 19 to 35, wherein the network node comprises a gNB-CU, gNB-CU-CP or eNB-CU.

37. The method of any of embodiments 19 to 36, wherein the mobility procedure

comprises a conditional handover, conditional resume, conditional reconfiguration with sync, conditional reconfiguration or conditional reestablishment procedure.

38. The method of any of embodiments 19 to 37, wherein the condition comprises

whether a signal strength of the target cell associated with the base station is greater than a signal strength of a serving cell of the UE by a first threshold, and/or whether the signal strength of the target cell is greater than a signal strength threshold.

39. The method of any of the previous embodiments, further comprising:

- providing user data; and

- forwarding the user data to a host computer via the transmission to the base station.

Group C Embodiments

40. Apparatus comprising:

- processing circuitry configured to perform any of the steps of any of the

Group A embodiments; and

- power supply circuitry configured to supply power to the wireless device.

41. Apparatus comprising:

- an antenna configured to send and receive wireless signals; - radio front-end circuitry connected to the antenna and to processing circuitry, and configured to condition signals communicated between the antenna and the processing circuitry;

- the processing circuitry being configured to perform any of the steps of any of the Group A embodiments;

- an input interface connected to the processing circuitry and configured to allow input of information into the apparatus to be processed by the processing circuitry;

- an output interface connected to the processing circuitry and configured to output information from the UE that has been processed by the processing circuitry; and

- a battery connected to the processing circuitry and configured to supply

power to the apparatus. The communication system of embodiment 24 further including the base station. The communication system of embodiment 24 or 25, further including the UE, wherein the UE is configured to communicate with the base station. The communication system of any of embodiments 24 to 26, wherein:

- the processing circuitry of the host computer is configured to execute a host application, thereby providing the user data; and

- the UE comprises processing circuitry configured to execute a client

application associated with the host application. A method implemented in a communication system including a host computer, a base station and a user equipment (UE), the method comprising:

- at the host computer, providing user data; and

- at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station, wherein the base station performs any of the steps of any of the Group A embodiments. The method of embodiment 28, further comprising, at the base station, transmitting the user data. The method of embodiment 28 or 29, wherein the user data is provided at the host computer by executing a host application, the method further comprising, at the UE, executing a client application associated with the host application. A user equipment (UE) configured to communicate with a base station, the UE comprising a radio interface and processing circuitry configured to performs the method of any of embodiments 28 to 30. A communication system including a host computer comprising a communication interface configured to receive user data originating from a transmission from a user equipment (UE) to a base station, wherein the base station comprises a radio interface and processing circuitry, the base station’s processing circuitry configured to perform any of the steps of any of the Group A embodiments. The communication system of embodiment 32 further including the base station. The communication system of embodiment 32 or 33, further including the UE, wherein the UE is configured to communicate with the base station. The communication system of any of embodiments 32 to 34, wherein:

- the processing circuitry of the host computer is configured to execute a host application;

- the UE is configured to execute a client application associated with the host application, thereby providing the user data to be received by the host computer.