TITLE

NEIGHBOR RELATIONSHIP MECHANISM FOR LTE-NEW RADIO INTERWORKING FOR

WIRELESS NETWORKS

TECHNICAL FIELD

[0001] This description relates to communications.

BACKGROUND

[0002] A communication system may be a facility that enables communication between two or more nodes or devices, such as fixed or mobile communication devices. Signals can be carried on wired or wireless carriers.

[0003] An example of a cellular communication system is an architecture that is being standardized by the 3 ^rd Generation Partnership Project (3GPP). A recent development in this field is often referred to as the Long Term Evolution (LTE) of the Universal Mobile

Telecommunications System (UMTS) radio-access technology. E-UTRA (evolved UMTS Terrestrial Radio Access) is the air interface of 3GPP's Long Term Evolution (LTE) upgrade path for mobile networks. In LTE, base stations or access points (APs), which are referred to as enhanced Node AP (eNBs), provide wireless access within a coverage area or cell. In LTE, mobile devices, or mobile stations are referred to as user equipments (UE). LTE has included a number of improvements or developments.

[0004] 5G New Radio (NR) development is part of a continued mobile broadband evolution process to meet the requirements of 5G, similar to earlier evolution of 3G & 4G wireless networks. A goal of 5G is to provide significant improvement in wireless

performance, which may include new levels of data rate, latency, reliability, and security. 5G NR may also scale to efficiently connect the massive Internet of Things (loT), and may offer new types of mission-critical services.

SUMMARY

[0005] According to an example implementation, a method may include establishing a connection between a first base station of a first radio access technology and a user device; receiving, by the first base station from the user device, a measurement report including an identifier for a second base station of a second radio access technology and an identifier for an anchor base station for the second base station, the anchor base station being of the first radio access technology, wherein the second base station of the second radio access technology is configured for communication with the anchor base station of the first radio access technology; determining, by the first base station based on the identifier for the second base station, that the first base station does not have an interface to the second base station; obtaining, by the first base station based on communication between the first base station and the anchor base station via a core network, an address of the second base station; and establishing, by the first base station based on the address of the second base station, an interface with the second base station for performing communications between the first base station and the second base station.

[0006] According to an example implementation, an apparatus includes at least one processor and at least one memory including computer instructions, when executed by the at least one processor, cause the apparatus to: establish a connection between a first base station of a first radio access technology and a user device; receive, by the first base station from the user device, a measurement report including an identifier for a second base station of a second radio access technology and an identifier for an anchor base station for the second base station, the anchor base station being of the first radio access technology, wherein the second base station of the second radio access technology is configured for communication with the anchor base station of the first radio access technology; determine, by the first base station based on the identifier for the second base station, that the first base station does not have an interface to the second base station; obtain, by the first base station based on communication between the first base station and the anchor base station via a core network, an address of the second base station; and establish, by the first base station based on the address of the second base station, an interface with the second base station for performing communications between the first base station and the second base station.

[0007] According to an example implementation, an apparatus includes means for establishing a connection between a first base station of a first radio access technology and a user device; means for receiving, by the first base station from the user device, a

measurement report including an identifier for a second base station of a second radio access technology and an identifier for an anchor base station for the second base station, the anchor base station being of the first radio access technology, wherein the second base station of the second radio access technology is configured for communication with the anchor base station of the first radio access technology; means for determining, by the first base station based on the identifier for the second base station, that the first base station does not have an interface to the second base station; means for obtaining, by the first base station based on communication between the first base station and the anchor base station via a core network, an address of the second base station; and means for establishing, by the first base station based on the address of the second base station, an interface with the second base station for performing communications between the first base station and the second base station.

[0008] According to an example implementation, a computer program product includes a computer-readable storage medium and storing executable code that, when executed by at least one data processing apparatus, is configured to cause the at least one data processing apparatus to perform a method including: establishing a connection between a first base station of a first radio access technology and a user device; receiving, by the first base station from the user device, a measurement report including an identifier for a second base station of a second radio access technology and an identifier for an anchor base station for the second base station, the anchor base station being of the first radio access technology, wherein the second base station of the second radio access technology is configured for communication with the anchor base station of the first radio access technology; determining, by the first base station based on the identifier for the second base station, that the first base station does not have an interface to the second base station; obtaining, by the first base station based on communication between the first base station and the anchor base station via a core network, an address of the second base station; and establishing, by the first base station based on the address of the second base station, an interface with the second base station for performing communications between the first base station and the second base station.

[0009] According to an example implementation, a method may include establishing, by a serving Long Term Evolution (LTE) base station, a connection between the serving LTE base station and a user device; receiving, by the serving LTE base station from the user device, a measurement report including an identifier for a New Radio (5G) base station and an identifier for an anchor LTE base station for the New Radio base station; determining, by the serving LTE base station based on the identifier for the New Radio base station, that the serving LTE base station does not have an interface to the New Radio base station;

obtaining, by the serving LTE base station based on communication between the serving LTE base station and the anchor LTE base station via a core network, an address of the New Radio base station; and establishing, by the serving LTE base station based on the address of the New Radio base station, an interface with the New Radio base station for performing communications between the serving LTE base station and the New Radio base station. .

[0010] According to an example implementation, an apparatus includes at least one processor and at least one memory including computer instructions, when executed by the at least one processor, cause the apparatus to: establish, by a serving Long Term Evolution (LTE) base station, a connection between the serving LTE base station and a user device; receive, by the serving LTE base station from the user device, a measurement report including an identifier for a New Radio (5G) base station and an identifier for an anchor LTE base station for the New Radio base station; determine, by the serving LTE base station based on the identifier for the New Radio base station, that the serving LTE base station does not have an interface to the New Radio base station; obtain, by the serving LTE base station based on communication between the serving LTE base station and the anchor LTE base station via a core network, an address of the New Radio base station; and establish, by the serving LTE base station based on the address of the New Radio base station, an interface with the New Radio base station for performing communications between the serving LTE base station and the New Radio base station.

[0011] According to an example implementation, a method may include establishing a connection between a first base station of a first radio access technology and a user device; receiving, by the user device, information transmitted from a second base station of a second radio access technology including an identifier for the second base station and an identifier for an anchor base station for the second base station, the anchor base station being of the first radio access technology; and sending, by the user device to the first base station, a measurement report including the identifier for the second base station and the identifier for the anchor base station for the second base station..

[0012] According to an example implementation, an apparatus includes at least one processor and at least one memory including computer instructions, when executed by the at least one processor, cause the apparatus to: establish a connection between a first base station of a first radio access technology and a user device; receive, by the user device, information transmitted from a second base station of a second radio access technology including an identifier for the second base station and an identifier for an anchor base station for the second base station, the anchor base station being of the first radio access technology; and send, by the user device to the first base station, a measurement report including the identifier for the second base station and the identifier for the anchor base station for the second base station.

[0013] According to an example implementation, a method may include transmitting, by a first base station of a first radio access technology, an identifier for the first base station and an identifier for an anchor base station of the first base station, the anchor base station being of a second radio access technology; wherein the first base station is configured for communication with the anchor base station.

[0014] According to an example implementation, an apparatus includes at least one processor and at least one memory including computer instructions, when executed by the at least one processor, cause the apparatus to: transmit, by a first base station of a first radio access technology, an identifier for the first base station and an identifier for an anchor base station of the first base station, the anchor base station being of a second radio access technology; wherein the first base station is configured for communication with the anchor base station.

[0015] According to an example implementation, a method may include establishing a communication interface, by a serving Long Term Evolution (LTE) base station, with a New Radio (5G) base station via an anchor LTE base station for the New Radio base station based on an identifier for the anchor LTE base station that is broadcast by the New Radio base station; wherein the New Radio base station is configured for communication with the anchor LTE base station including the New Radio base station either being configured with an address of the anchor LTE base station or having established an interface with the anchor LTE base station. .

[0016] According to an example implementation, an apparatus includes at least one processor and at least one memory including computer instructions, when executed by the at least one processor, cause the apparatus to: establish a communication interface, by a serving Long Term Evolution (LTE) base station, with a New Radio (5G) base station via an anchor LTE base station for the New Radio base station based on an identifier for the anchor LTE base station that is broadcast by the New Radio base station; wherein the New Radio base station is configured for communication with the anchor LTE base station including the New Radio base station either being configured with an address of the anchor LTE base station or having established an interface with the anchor LTE base station.

[0017] According to an example implementation, a method may include establishing, by a first base station of a first radio access technology, a connection between the first base station and a user device; receiving, by the first base station from the user device, a measurement report including an identifier for a second base station of a second radio access technology; determining, by the first base station based on the identifier for the second base station, that the first base station does not have a communications interface to the second base station; sending, by the first base station to the user device, an access request including an identifier of the second base station to which a random access procedure should be performed to cause the user device to provide an identifier of the first base station to the second base station via a random access procedure performed by the user device with the second base station; and receiving, by the first base station from the second base station, a request to establish an interface for communication between the first base station and the second base station..

[0018] According to an example implementation, an apparatus includes at least one processor and at least one memory including computer instructions, when executed by the at least one processor, cause the apparatus to: establish, by a first base station of a first radio access technology, a connection between the first base station and a user device; receive, by the first base station from the user device, a measurement report including an identifier for a second base station of a second radio access technology; determine, by the first base station based on the identifier for the second base station, that the first base station does not have a communications interface to the second base station; send, by the first base station to the user device, an access request including an identifier of the second base station to which a random access procedure should be performed to cause the user device to provide an identifier of the first base station to the second base station via a random access procedure performed by the user device with the second base station; and receive, by the first base station from the second base station, a request to establish an interface for communication between the first base station and the second base station. [0019] According to an example implementation, a method may include establishing a communication interface, by a serving Long Term Evolution (LTE) base station with a New Radio (5G) base station, based on a New Radio access request message, sent by the serving LTE base station to a user device that has reported an identifier of the New Radio base station, the New Radio access request message instructing the user device to perform a random access procedure with New Radio and provide an identifier of the serving LTE base station to the New Radio base station via the random access procedure.

[0020] According to an example implementation, an apparatus includes at least one processor and at least one memory including computer instructions, when executed by the at least one processor, cause the apparatus to: establish a communication interface, by a serving Long Term Evolution (LTE) base station with a New Radio (5G) base station, based on a New Radio access request message, sent by the serving LTE base station to a user device that has reported an identifier of the New Radio base station, the New Radio access request message instructing the user device to perform a random access procedure with New Radio and provide an identifier of the serving LTE base station to the New Radio base station via the random access procedure.

[0021] According to an example implementation, a method may include establishing a connection between a user device and a first base station of a first radio access technology; sending, by the user device to the first base station, a measurement report including an identifier for a second base station of a second radio access technology; receiving, by the user device from the first base station, an access request including an identifier of the second base station to which a random access procedure should be performed to cause the user device to provide an identifier of the first base station to the second base station via a random access procedure; and providing, by the user device, an identifier of the first base station to the second base station via a random access procedure. .

[0022] According to an example implementation, an apparatus includes at least one processor and at least one memory including computer instructions, when executed by the at least one processor, cause the apparatus to: establish a connection between a user device and a first base station of a first radio access technology; send, by the user device to the first base station, a measurement report including an identifier for a second base station of a second radio access technology; receive, by the user device from the first base station, an access request including an identifier of the second base station to which a random access procedure should be performed to cause the user device to provide an identifier of the first base station to the second base station via a random access procedure; and provide, by the user device, an identifier of the first base station to the second base station via a random access procedure.

[0023] According to an example implementation, a method may include transmitting, by a first base station of a first radio access technology, an identifier for the first base station, wherein the first base station is configured for communication with an anchor base station of a second radio access technology; receiving, by the first base station from a user device via a random access procedure, an identifier of a second base station of the second radio access technology; sending, by the first base station to the anchor base station, an address request for the second base station, the address request including the identifier for the second base station; receiving, by the first base station from the anchor base station, the address of the second base station; and establishing, by the first base station based on the received address of the second base station, an interface for communicating with the second base station.

[0024] According to an example implementation, an apparatus includes at least one processor and at least one memory including computer instructions, when executed by the at least one processor, cause the apparatus to: transmit, by a first base station of a first radio access technology, an identifier for the first base station, wherein the first base station is configured for communication with an anchor base station of a second radio access technology; receive, by the first base station from a user device via a random access procedure, an identifier of a second base station of the second radio access technology; send, by the first base station to the anchor base station, an address request for the second base station, the address request including the identifier for the second base station; receive, by the first base station from the anchor base station, the address of the second base station; and establish, by the first base station based on the received address of the second base station, an interface for communicating with the second base station.

[0025] According to an example implementation, a method may include establishing a connection between a first secondary base station of a first radio access technology and a user device, the first connection being part of a dual connectivity for the user device where the user device is connected via the first connection to the first secondary base station and is connected via a second connection to a master base station of a second radio access technology; receiving, by the first secondary base station of the dual connectivity from the user device, a measurement report including an identifier for a second secondary base station of the first radio access technology and an identifier for an anchor base station for the second secondary base station, the anchor base station being of the second radio access technology, wherein both the first secondary base station and the second secondary base station are each configured for communication with the anchor base station; obtaining, by the first secondary base station from the anchor base station, an address of the second secondary base station based on the identifier for the second secondary base station; and sending, by the first secondary base station to the master base station, a secondary base station change request, including the address of the second secondary base station, to request the master base station to change the secondary base station for the dual connectivity of the user device from the first secondary base station to the second secondary base station..

[0026] According to an example implementation, an apparatus includes at least one processor and at least one memory including computer instructions, when executed by the at least one processor, cause the apparatus to: establish a connection between a first secondary base station of a first radio access technology and a user device, the first connection being part of a dual connectivity for the user device where the user device is connected via the first connection to the first secondary base station and is connected via a second connection to a master base station of a second radio access technology; receive, by the first secondary base station of the dual connectivity from the user device, a measurement report including an identifier for a second secondary base station of the first radio access technology and an identifier for an anchor base station for the second secondary base station, the anchor base station being of the second radio access technology, wherein both the first secondary base station and the second secondary base station are each configured for communication with the anchor base station; obtain, by the first secondary base station from the anchor base station, an address of the second secondary base station based on the identifier for the second secondary base station; and send, by the first secondary base station to the master base station, a secondary base station change request, including the address of the second secondary base station, to request the master base station to change the secondary base station for the dual connectivity of the user device from the first secondary base station to the second secondary base station.

[0027] The details of one or more examples of implementations are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG. 1 is a block diagram of a wireless network according to an example implementation.

[0029] FIG. 2A is a diagram illustrating an operation of a wireless network according to an example implementation.

[0030] FIG. 2B is a diagram illustrating an operation of a wireless network according to another example implementation.

[0031] FIG. 3 is a diagram illustrating an operation of a wireless network according to another example implementation.

[0032] FIG. 4 is a flow chart illustrating operation of a base station according to an example implementation.

[0033] FIG. 5 is a flow chart illustrating operation of a base station according to another example implementation.

[0034] FIG. 6 is a flow chart illustrating operation of a base station according to another example implementation.

[0035] FIG. 7 is a flow chart illustrating operation of a base station according to another example implementation.

[0036] FIG. 8 is a flow chart illustrating operation of a base station according to another example implementation.

[0037] FIG. 9 is a flow chart illustrating operation of a base station according to another example implementation.

[0038] FIG. 10 is a flow chart illustrating operation of a base station according to another example implementation.

[0039] FIG. 1 1 is a flow chart illustrating operation of a base station according to another example implementation.

[0040] FIG. 12 is a flow chart illustrating operation of a base station according to another example implementation.

[0041] FIG. 13 is a flow chart illustrating operation of a base station according to another example implementation. [0042] FIG. 14 is a block diagram of a node or wireless station (e.g., base

station/access point or mobile station/user device) according to an example implementation.

DETAILED DESCRIPTION

[0043] FIG. 1 is a block diagram of a wireless network 130 according to an example implementation. In the wireless network 130 of FIG. 1 , user devices 131 , 132, 133 and 135, which may also be referred to as mobile stations (MSs) or user equipment (UEs), may be connected (and in communication) with a base station (BS) 134, which may also be referred to as an access point (AP), an enhanced Node B (eNB), a gNB (which may be a New Radio (5G) base station) or a network node. At least part of the functionalities of an access point (AP), base station (BS) or (e)Node B (eNB) may be also be carried out by any node, server or host which may be operably coupled to a transceiver, such as a remote radio head. BS (or AP) 134 provides wireless coverage within a cell 136, including to user devices 131 , 132, 133 and 135. Although only four user devices are shown as being connected or attached to BS 134, any number of user devices may be provided. BS 134 is also connected to a core network 150 via a S1 interface 151 . This is merely one simple example of a wireless network, and others may be used.

[0044] A user device (user terminal, user equipment (UE)) may refer to a portable computing device that includes wireless mobile communication devices operating with or without a subscriber identification module (SIM), including, but not limited to, the following types of devices: a mobile station (MS), a mobile phone, a cell phone, a smartphone, a personal digital assistant (PDA), a handset, a device using a wireless modem (alarm or measurement device, etc.), a laptop and/or touch screen computer, a tablet, a phablet, a game console, a notebook, and a multimedia device, as examples. It should be appreciated that a user device may also be a nearly exclusive uplink only device, of which an example is a camera or video camera loading images or video clips to a network.

[0045] In LTE (as an example), core network 150 may be referred to as Evolved Packet Core (EPC), which may include a mobility management entity (MME) which may handle or assist with mobility/handover of user devices between BSs, one or more gateways that may forward data and control signals between the BSs and packet data networks or the Internet, and other control functions or blocks.

[0046] The various example implementations may be applied to a wide variety of wireless technologies or wireless networks, such as LTE, LTE-A, 5G, cmWave, and/or mmWave band networks, or any other wireless network. LTE, 5G, cmWave and mmWave band networks are provided only as illustrative examples, and the various example implementations may be applied to any wireless technology/wireless network.

[0047] Various example implementations may relate, for example, to 5G radio access systems (or other systems) with support for Massive MIMO (multiple input, multiple output) and optimized for operating in high carrier frequencies such as cmWave frequencies (e.g. from 3 GHz onwards) or mmWave frequencies, as examples, according to an illustrative example implementation. Those illustrative systems are typically characterized by the need for high antenna gain to compensate for increased pathloss and by the need for high capacity and high spectral efficiency to respond to ever increasing wireless traffic. Some of the various example implementations are described with respect to LTE BSs and New Radio (5G) BSs. However, LTE and New Radio (5G) are merely example radio access technologies (RATs), and nodes, devices or BSs of other RATs may also be used. Thus, the various example implementations may be performed with respect to any RATs, and LTE and New Radio (5G) are some example RATs.

[0048] According to an example implementation, LTE BSs (eNBs) may communicate via a X2 interface (a BS-to-BS interface for communications, established between two BSs), e.g., to allow the BSs to communicate or exchange signalling information when needed, such as, for example, to exchange load or interference information, and/or to exchange handover related information to support mobility of UEs/user devices between BSs.

[0049] According to an example implementation, in order to set up a BS-to-BS (e.g., X2) interface between two BSs, a BS may first identify a transport network layer (TNL) address (e.g., Internet Protocol/IP address) of a neighbour BS. For example, A BS may determine an IP address of another BS via either configuration (e.g., where a BS is configured with the IP address of a neighbour BS), or via Automatic Neighbour Relationship (ANR) function, which is part of Self Organizing Network (SON) function. After setting up a TNL (transport network layer) based on the X2 IP address of a neighbour BS, a X2 (BS-to- BS) interface may be set up between two BSs by an initiating BS sending an X2 setup request to one or more (neighbour) BSs including information about each cell the initiating BS provides (such as a physical cell identifier (PCI), the frequency band, tracking area identity, and/or other information). The receiving BS (that receives the X2 setup request) may send an X2 setup reply that may provide the same or similar information, to allow the X2 (BS-to- BS) interface to be established between the two BSs. After an X2 interface has been established between two BSs, the BSs may then exchange signalling over the X2 interface, e.g., signalling related to load or interference and/or signalling related to handover or mobility of user devices/UEs.

[0050] A BS may obtain a transport network layer (TNL) address, such as an IP address, of a neighbor node via LTE ANR function, which may rely on a mobility management entity (MME) of a core network to obtain or retrieve a TNL/IP address of a target BS and return it to a requesting BS. For example, LTE ANR may include one or more of the following operations: BS sends RRC (radio resource control) Measurement Command to UE/user device to measure the PCI (physical cell identifier) along with ECGI (EUTRAN cell group identifier) of any measured neighbor BSs, e.g., when the serving BS (that is serving and/or connected to the UE) has a need for any measurements of neighbor BSs. The UE/user device may, for example, receive system information from one or more neighbor BSs, where the system information broadcast by each BS may include the PCI and ECGI of the BS. The UE/user device reports the PCI and ECGI of measured neighbor cells to its

serving/connected BS (which requested this information). The serving BS may compare the ECGI to its ANR neighbor relation table (which may identify or list neighbor BSs to which it has an X2 interface established). If the reported ECGI is already part of BSs which are connected via X2 interface (e.g., PCI/ECGI of the reported BS is in the serving BSs neighbor relation table), then no further action is required (since the serving BS already has the IP address of such neighbor BS and/or already has an X2 interface established with such neighbor BS/cell). The serving BS needs a transport network layer (TNL) address (e.g., IP address) to establish the X2 interface with a neighbor BS. The serving BS may update its neighbor relation table to indicate the new cell as a possible neighbor BS/cell.

[0051] If the reported ECGI is not part of any BS connected via X2 to the serving BS (e.g., the BS ID or ECGI of the neighbor cell/neighbor BS is not in the neighbor relation table of the serving BS), the serving BS may send a S1 Direct Configuration Transfer message with the Target BS identifier (BS ID) derived from ECGI to MME of core network. The message may include a SON Request to obtain TNL (e.g., IP) Address of the target BS for X2 interface setup. MME/core network forwards this message to the target BS, and target BS sends back its TNL/IP address for X2. MME send back the TNL/IP address of target BS to the originating/serving BS/eNB. The serving BS may then setup an X2 interface with the target BS based on the received TNL/IP address of the target BS/eNB.

[0052] According to an example implementation, it may also be useful to allow BS-to- BS (e.g., X2) interfaces to be established between BSs of different radio access technologies (different RATs), e.g., between LTE BSs and New Radio (5G) BSs. However, in at least some cases, New Radio BSs will not have a connection to the LTE core network (MME) function. Therefore, the LTE ANR function (e.g., using the LTE MME/core network to retrieve or obtain an address of another BS) may not be used by an LTE BS (as used in LTE) to obtain an address of a New Radio (5G) BS, because, at least in some cases, the New Radio (5G) BS is not connected to the LTE core network/MME. Other (alternative) techniques are desirable to allow a New Radio BS to obtain an address (e.g., TNL or IP address) of an LTE BS, and to allow a LTE BS to obtain an address of a New Radio base station, e.g., to allow BS-to-BS interfaces to be established between LTE BSs and New Radio BSs.

[0053] According to an example implementation, in a network that may include both LTE BSs and New Radio (5G) BSs, a New Radio BS may be configured (e.g., which may be a static configuration) for communication with an anchor LTE BS (without the need to use ANR to obtain the address of the anchor LTE BS). As an example of being configured for communication with an anchor LTE BS, a New Radio BS may be configured (static configuration, stored in memory of New Radio BS) with an address (e.g., TNL address or IP address) of an anchor LTE BS, which may allow the New Radio BS to setup a BS-to-BS (e.g., X2) interface with the anchor LTE BS, without the need for ANR or other technique to obtain the address of the anchor LTE BS. Also, a New Radio (5G) BS may also change its anchor LTE BS to any of the connected LTE BSs, e.g., once the New Radio BS has established a communication interface with other LTE BSs, e.g., through address discovery. Thus, according to an example implementation, the pre-configured (static configured) anchor LTE BS for a New Radio BS may typically be used initially as the anchor LTE BS, e.g., at least until the New Radio BS has established a communications interface (e.g., X2 interface) with one or more additional LTE BSs. At such time, when the New Radio BS has established interfaces with other LTE BSs, the New Radio BS may select one of these other LTE BSs to be its anchor LTE BS (e.g., based on which LTE BS that may be the nearest/closest to the New Radio BS). Thus, a New Radio BS may change its anchor LTE BS.

[0054] Also, LTE BSs may establish an X2 interface with other LTE BSs (e.g., via ANR), and each LTE BS may be in communication with the LTE core network (e.g., MME). Thus, for example, a New Radio BS may be configured (stored in memory the New Radio BS) with the TNL/IP address of an anchor LTE BS, and may then establish a BS-to-BS (e.g., X2) interface with the anchor LTE BS. The illustrative examples of FIGs. 2-3 are examples that allow a New Radio (5G) BS to establish a BS-to-BS (e.g., X2) interface with one or more LTE BSs, and that allow a LTE BS to establish a BS-to-BS interface with a New Radio BS.

[0055] FIG. 2A is a diagram illustrating an operation of a wireless network according to an example implementation. The following nodes are shown within the diagrams of FIGs. 2 and 3: a UE (user device) 210, a New Radio (5G) BS 212, an anchor LTE BS 214 (for the New Radio BS 212), a MME 216 (part of LTE core network), and a serving LTE BS 218. New Radio BS 212 is configured (e.g., as part of OAM (operations, administration, maintenance) configuration) for communication with the anchor LTE BS 214, e.g., where the New Radio BS 212 is configured with an address (e.g., TNL or IP address) of the anchor LTE BS.

[0056] Referring to FIG. 2A, at 230, New Radio (NR) BS 212 establishes a BS-to-BS (e.g., X2) interface with the anchor LTE BS 214 based on the address of the anchor LTE BS 214. As an example, New Radio BS 212 may perform X2 interface setup with the anchor LTE BS 214 to establish the X2 interface between the New Radio BS 212 and anchor LTE BS 214.

[0057] At 234, New Radio node (5G BS) broadcasts system information, including an identifier of New Radio BS 212 (identifying a cell provided by or associated with the New Radio BS 212 and or an identifier of the BS 212) and an identifier of the anchor LTE BS 214 (identifying the anchor LTE BS for the New Radio BS 212 or identifying a cell associated with the anchor LTE BS). For example, the identifier of the New Radio BS 212 may include at least one of a physical cell identifier (PCI) and a EUTRAN cell group identifier (ECGI) of a cell provided by or associated with the New Radio BS 212 and/or a BS identifier (BS ID, or gNB ID) that identifies the anchor LTE BS 214. Also, for example, the identifier for the anchor LTE BS 214 may include an ECGI (or a PCI and ECGI) of a cell provided by (or associated with) the anchor LTE BS 214, or a BS ID or eNB ID that identifies the anchor LTE BS 214. For example, the identifier for the anchor LTE BS 214 may be provided as a 'LTE-Cell-ldentifier' that identifies a cell for the anchor LTE BS 214.

[0058] Thus, in this manner, a New Radio BS 212 may broadcast or transmit, e.g., within its system information or other transmission, both an identifier (e.g., one or more of a PCI, ECGI, BS ID/gNB ID) of the New Radio BS and an identifier (e.g., one or more of a PCI, ECGI, BS ID/gNB ID) of the anchor LTE BS 214 for the New Radio BS 212. This may allow other nodes (e.g., other BSs and/or UEs) to measure signals received from New Radio BSs, and then identify both the identifier for the New Radio BS and an identifier for the anchor LTE BS for the New Radio BS.

[0059] At 236, a radio resource control (RRC) connection is established between the UE 210 and serving LTE BS 218, e.g., via random access.

[0060] At 238, the serving LTE BS 218 may send a measurement command (or send measurement configuration information) to the UE 210, indicating that the UE 210 should measure and report signals received from one or more BSs, e.g., for all RATs, or for just New Radio (5G) BSs, etc., or other measurement configuration. Therefore, the measurement command might indicate to measure 5G cells, or could be to measure BSs for all RATs - such as both NR (5G) and LTE). The UE 210 may then measure signals received from one or more BSs, including measuring signals received from the New Radio BS 212, and

determining, based on received signals, the identifier (e.g., ECGI and/or BS ID) of the New Radio BS 212 and the identifier (e.g., ECGI and/or BS ID) of the anchor LTE BS (both of which may be transmitted/broadcasted by the New Radio BS 212).

[0061] At 240, UE 210 sends a measurement report to the serving LTE BS 218, including the identifier for the New Radio BS 212 and the identifier for the anchor LTE BS 214 (and possibly identifiers for other BSs for which signals are being reported in the

measurement report). The serving LTE BS 218 may determine, based on the identifier for the New Radio BS 212, whether or not the serving LTE BS 218 has an (e.g., X2) interface established (or set up) between the serving LTE BS 218 and the New Radio BS 212. For example, the serving LTE BS 218 may compare the identifier (e.g., PCI, ECGI and/or BS ID) for the New Radio BS 212 to entries of its neighbour relation table (of the serving LTE BS 218) to determine if the identifier for the New Radio BS 212 is present in the neighbour relation table (e.g., indicating that an X2 interface already exists for the New Radio BS 212). If a BS-to-BS interface already exists between the serving LTE BS 218 and the New Radio BS 212, then the process may stop. If, on the other hand, a BS-to-BS (e.g., X2) interface does not exist between the serving LTE BS 218 and one of the reported New Radio (5G) BSs (e.g., the New Radio BS 212), then the process flow continues to operation s 242 and 244, FIG. 2A. [0062] At operation 242, the serving LTE BS 218 triggers ANR (automatic neighbour relation) function to be used to retrieve an address of the New Radio BS 212 via the MME 216 and the anchor LTE BS 214. First, a query (e.g., including the identifier for the New Radio BS 212 and an identifier for the anchor LTE BS 214) for the address (Query for NR- TNL/IP address) is sent from serving LTE BS 218 to the MME 216. MME 216, based on the received identifier for the anchor LTE BS 214, then forwards the Query (including the identifier for the New Radio BS 212) for the address to the anchor LTE BS 214. LTE BS 214, based on the identifier for the New Radio BS 212, determines the address (e.g., TNL or IP address) of the New Radio BS 212, and sends a Response (including the address of the New Radio BS 212) to the MME 216, which forwards the response to the serving/requesting LTE BS 218. In this manner, the serving LTE BS 218 may use ANR to obtain the address of the New Radio (5G) BS 212 via the MME and the anchor LTE BS 214. Thus, the serving LTE BS may send a query, e.g., a "NR-TNL-Query" request - sent to MME 216 for ANR, including the New Radio BS identifier (e.g., NR ECGI, or NR BS ID for New Radio BS 212), which can be used by the MME 216 to determine an address of the New Radio BS 212.

[0063] At 244, based on the received address of the New Radio BS 212, the serving/requesting LTE BS 218 establishes a BS-to-BS (e.g., X2) interface with the New Radio BS 212, e.g., by sending a X2 setup request, and receiving a X2 setup reply.

[0064] According to an example implementation, the anchor LTE BS 214 may be collocated with the New Radio BS 212. In such case, these collocated BSs could have same or different TNL (e.g., IP) addresses. Thus, for example, there may be changes to System Information contents of New Radio BS for ANR purpose. In case of collocated anchor LTE BS+ New Radio BS, this information is also useful to obtain X2 IP address of the anchor LTE BS along with address of New Radio BS (these addresses may be same, or may be different). If the same, then the address of both may be obtained via measurement of only one address broadcast by New Radio BS/anchor LTE BS within system information.

[0065] FIG. 2B is a diagram illustrating an operation of a wireless network according to another example implementation. In the example shown in FIG. 2B, dual connectivity (dual connections) are initially established between the UE 210 and the LTE master BS (MeNB) 250 (as a master node/BS) and a New Radio secondary BS (SeNB-S) 252. As part of dual connectivity for a user device/UE 210, UE 210 may typically establish a first connection with a master BS (e.g., LTE Master BS/MeNB), and then may establish a second connection with a secondary BS (e.g., a secondary New Radio BS, or NR SeNB)). A secondary BS (or secondary eNB) change procedure (or secondary BS handover) may be performed or used to cause a change of the secondary BS for the dual connectivity of the user device/UE 210 from a source secondary New Radio BS (SeNB-S 252, or source NR BS) to a target secondary New Radio BS (SeNB-T 254, or target NR BS), e.g., based on a measurement report(s) provided by UE 210. In this illustrative example, an anchor LTE BS 214 is the anchor LTE BS for both the source secondary New Radio BS (SeNB-S 252) and the target New Radio BS (SeNB-T 254). Thus, according to an example implementation, the source New Radio BS 252 may obtain a TNL/IP address of the target New Radio BS 254 by querying the anchor LTE BS 214, because BS 214 is the anchor LTE BS for both source New Radio BS (SeNB-S 252) and target New Radio BS (SeNB-T 254). Thus, anchor LTE BS 214 knows (e.g., has stored in memory) the TNL/IP addresses of each of these New Radio BSs (252, 254).

[0066] Although not shown in the example illustrated in FIG. 2B, similar to 230 in FIG. 2A, both the New Radio BSs (NR SeNB-S 252, and NR SeNB-T 254) are configured with the address of the anchor LTE BS 214. Thus, both of the New Radio BSs (NR SeNB-S 252, and NR SeNB-T 254) may establish an interface (e.g., X2 interface) to the anchor LTE BS 214. Or, each of the New Radio BSs may have selected anchor LTE BS 214 to be its anchor LTE BS.

[0067] At 260, a UE 210 may establish dual connectivity (e.g., establish separate connections) with the LTE master BS (LTE MeNB) 250 and source New Radio BS (NR SeNB-S 252).

[0068] Although not shown, similar to 234 in FIG. 2A, each New Radio BS may transmit/broadcast system information, e.g., including an identifier of the New Radio BS (e.g., NR ECGI, PCI and/or NR BS ID for the NR BS) and an identifier (e.g., LTE-Cell-ldentifier, such as an ECGI, or LTE BS ID) of the anchor LTE BS for the New Radio BS.

[0069] At 262, UE 210 may receive from source New Radio BS (NR SeNB-S 252) a command to measure signals from New Radio BSs, and provide a measurement report. At 262, UE 210 may send a measurement report that may include at least an identifier (e.g., NR ECGI +PCI and/or NR BS ID for the NR BS) for the target New Radio BS (NR SeNB-T 254) and an identifier (e.g., LTE-Cell-ldentifier, such as an LTE ECGI, or LTE BS ID) for the anchor LTE BS 214 of the target NR BS 254.

[0070] At 264, the source New Radio BS (NR SeNB-S 252) determines that the identified anchor LTE BS214 for the target New Radio BS (NR SeNB-T 254) is the same anchor LTE BS that it is using as an anchor LTE BS (thus, the source NR BS 252 may determine that it already has an interface to the anchor LTE BS 214 for the identified target NR BS 254, e.g., based on a lookup in a neighbor relation table of source NR BS 252 that includes ECGI/BSID of anchor LTE BS 214).

[0071] At 266, the source New Radio BS (NR SeNB-S 252) sends a query (e.g., a TNL-Address-Query, including the identifier (e.g., ECGI or BSID) of the target NR BS 254) to the anchor LTE BS 214 to request the TNL/IP address of the target NR BS 254.

[0072] At 268, the anchor LTE BS 214 determines the TNL/IP address for the target New Radio BS (NR SeNB-T 254) based on the identifier for the target NR BS 254. At 268, anchor LTE BS 214 returns the TNL or IP address of the target New Radio BS 254 to the source New Radio BS 252.

[0073] At 270, the source New Radio BS 252 sends a secondary NR BS change request or handover request (SeNB-change-Request) to the master BS (LTE MeNB) 250 to cause a change of the secondary NR BS from the source New Radio BS 252 to the target New Radio BS 254. The secondary New Radio BS change request may include the identifier (e.g., ECGI, or BS ID) of the target New Radio BS 254, and the TNL (or IP) address of the target New Radio BS 254.

[0074] At 272, the master BS (LTE MeNB) 250 initiates a secondary BS change procedure (e.g., by communicating with New Radio BSs 252 and 254, and by communicating with UE 210) to change the secondary New Radio BS from source New Radio BS 252 to the target New Radio BS 254. At 272, this change procedure (or handover) will cause the secondary connection between the UE 210 and the source secondary New Radio BS 252 to be terminated, and a new secondary connection (part of the dual connectivity with the UE 210) to be established between UE 210 and target New Radio BS 254. The connection between UE 210 and master LTE BS 250 will continue as it was before the change procedure.

[0075] FIG. 3 is a diagram illustrating an operation of a wireless network according to another example implementation. In this illustrative example shown in FIG. 3, the New Radio BS 212 broadcasts the identifier of the New Radio BS 212, but does not (necessarily) broadcast the identifier of the anchor LTE BS 214. Rather, in this example, the serving LTE BS 218 causes the UE to perform random access procedure with the New Radio BS, and thereby provide (via the random access procedure) the identifier of the serving/requesting LTE BS 218. The New Radio BS 212 may then send a request, to its anchor LTE BS 214, for the address of the serving LTE BS 218, and the anchor LTE BS 214 may then use ANR to obtain the address of the serving LTE BS 218, which is then returned to the New Radio BS via the anchor LTE BS. 214. Thus, in this example of FIG. 3, the New Radio BS may obtain the address of the serving/requesting LTE BS 218 by triggering the UE 210 to provide the identifier of the requesting/serving LTE BS 218 via random access procedure to the New Radio BS 212. Thus, in this example, UE 210 is a proxy for the serving/requesting LTE BS 218 (because the UE is in communication with the New Radio BS 212, while the serving LTE BS 218 is not).

[0076] Referring to FIG. 3, according to an example implementation, operation 310 is the same as or similar to operation 230 (FIG. 2A). Also, operations 312 and 314 are the same or similar to the operations 236, 238 (FIG. 2A).

[0077] The UE 210 may measure signals of one or more BSs, including signals of New Radio BS 212, including determining the identifier (e.g., ECGI, BS ID) of the New Radio BS 212. As noted, in this illustrative example, New Radio BS 212 does not (necessarily) transmit the identifier of its anchor LTE BS 214.

[0078] At 318, in response to the measurement command received at 314, the UE 210 sends a measurement report, including the identifier (e.g., PCI, ECGI and/or BS ID) of one or more BSs (including the identifier of the New Radio BS 212), to serving LTE BS 218. The serving LTE BS 218 may determine whether or not the serving LTE BS 218 has an interface established with New Radio BS 212 (e.g., based on a comparison of the identifier for the New Radio BS 212 to entries of its neighbour relation table). If an interface already exists for the reported New Radio BSs (including for the New Radio BS 212), then the process stops. If an interface has not been established for one of the reported New Radio BSs (e.g., for New Radio BS 212), then the process continues with operations 320, 322, 324, 326 and 328.

[0079] At 320, if there is no interface at the Serving LTE BS 218 for the New Radio BS 212, then the serving LTE BS 218 sends a New Radio (NR) Access Request message, e.g., as a RRC message (including the identifier for the New Radio BS 212 for which random access should be performed to) to the UE 210 to request that the UE 210 perform a random access procedure and provide an identifier for the serving LTE BS 218 to the New Radio BS 212 via the random access procedure. In this manner, the serving/requesting LTE BS 218 is contacting the New Radio BS 212 via a proxy (UE 210 is the proxy in this case).

[0080] At 322, UE performs random access procedure with New Radio BS, based on the received NR-Access-request message. At 322, for example, the UE may send a RACH (random access) preamble, receive a random access response with an uplink resource, and then may send a third message (e.g., msg 3) with identifier of serving LTE BS 218 (e.g., as a MeNB or Master eNB) to New Radio BS 212. Or the identifier for the serving LTE BS 218 may be sent in a first random access message sent to the New Radio BS 212, for example. Thus, UE 210 triggers RACH access with New Radio BS (NR BS). UE sends the identifier, e.g., ECGI or BS ID, in a message, such as in the first message of the random access procedure, or in a third message (equivalent to message 3 in LTE random access procedure) to New Radio BS 212. The New Radio BS 212 receives the identifier (e.g., ECGI and/or BS ID) of the serving LTE BS 218 via the random access procedure performed by UE 210.

[0081] New Radio BS 212 is not connected to MME 216 (and, thus, New Radio BS 212 cannot initiate ANR), but the anchor LTE BS 214 is connected to the MME 216 (thus, anchor LTE BS 214 can initiate ANR to obtain the address of the serving LTE BS 218).

[0082] At 324 and 326 (FIG. 3), in response to receiving the identifier (e.g., ECGI and/or BS ID) of the serving LTE BS 218, the New Radio BS 212 sends a Query for LTE address (e.g., Xx-Query-for-LTE-TNL) of the serving LTE BS 218 to the anchor LTE BS 214 (including the identifier of the serving LTE BS 218). Anchor LTE BS 214 initiates ANR, by forwarding the request (Query for LTE-Xx-TNL/IP) for the TNL/IP address of serving LTE BS 218 to the MME 216. MME 216 sends a request to serving LTE BS 218 and obtains a Response from the serving LTE BS 218 that includes the TNL/IP address of the serving LTE BS 218. MME 216 forwards the response to the anchor LTE BS 214 (including the address of the serving LTE BS 218) to the anchor LTE BS 214, and anchor LTE BS 214 forwards this response to the New Radio BS 212. In this manner, the New Radio BS 212 obtains the TNL/IP address of the serving/requesting LTE BS 218.

[0083] At 328, based on the received address of the serving LTE BS 218, the New Radio BS 212 establishes a BS-to-BS (e.g., X2) interface with the serving LTE BS 218, e.g., by sending a X2 setup request to the address of the serving LTE BS 218, and receiving a X2 setup reply.

[0084] Example 1 . FIG. 4 is a flow chart illustrating operation of a base station according to an example implementation. Operation 410 includes establishing a connection between a first base station of a first radio access technology and a user device. Operation 420 includes receiving, by the first base station from the user device, a measurement report including an identifier for a second base station of a second radio access technology and an identifier for an anchor base station for the second base station, the anchor base station being of the first radio access technology, wherein the second base station of the second radio access technology is configured for communication with the anchor base station of the first radio access technology. Operation 430 includes determining, by the first base station based on the identifier for the second base station, that the first base station does not have an interface to the second base station. Operation 440 includes obtaining, by the first base station based on communication between the first base station and the anchor base station via a core network, an address of the second base station. And, operation 450 includes establishing, by the first base station based on the address of the second base station, an interface with the second base station for performing communications between the first base station and the second base station.

[0085] Example 2. According to an example implementation, the method of example 1 , wherein the first base station comprises a Long Term Evolution (LTE) base station (LTE eNB); wherein the second base station comprises a New Radio (5G) base station (gNB); wherein the anchor base station for the second base station comprises an anchor LTE base station for the New Radio base station; wherein the New Radio base station being configured for communication with the anchor LTE base station comprises the New Radio base station either being configured with an address of the anchor LTE base station or having established an interface with the anchor LTE base station.

[0086] Example 3. According to an example implementation of the method of any of examples 1 -2, wherein the identifier for the second base station comprises at least one of: a first cell identifier that identifies a cell associated with the second base station; and a first base station identifier that identifies the second base station; and wherein the identifier for the anchor base station comprises at least one of: a second cell identifier that identifies a cell associated with the anchor base station; and a second base station identifier that identifies the second base station.

[0087] Example 4. According to an example implementation of the method of any of examples 1 -3, wherein the first cell identifier and the second cell identifier each comprise at least one of the following: a physical cell identifier (PCI); and a EUTRAN cell group identifier (ECGI).

[0088] Example 5. According to an example implementation of the method of any of examples 1 -4, wherein the identifier for the second base station comprises at least one of: a first cell identifier that identifies a cell associated with the New Radio (5G) base station; and a base station identifier (gNB identifier) that identifies the New Radio base station; and wherein the identifier for the anchor base station comprises at least one of: a second cell identifier that identifies a cell associated with the anchor Long Term Evolution (LTE) base station; and a base station identifier (eNB identifier) that identifies the anchor LTE base station.

[0089] Example 6: According to an example implementation of the method of any of examples 1 -5, wherein the determining comprises comparing, by the first base station, the identifier for the second base station to a list of identifiers for which the first base station has an interface established for communication; and determining, by the first base station based on the comparing, that the first base station does not have an interface established for communication with the second base station.

[0090] Example 7. An apparatus comprising at least one processor and at least one memory including computer instructions, when executed by the at least one processor, cause the apparatus to perform a method of any of examples 1 -6.

[0091] Example 8. An apparatus comprising means for performing the method of any of examples 1 -6.

[0092] Example 9. FIG. 5 is a flow chart illustrating operation of a base station according to another example implementation. Operation 510 includes establishing, by a serving Long Term Evolution (LTE) base station, a connection between the serving LTE base station and a user device. Operation 520 includes receiving, by the serving LTE base station from the user device, a measurement report including an identifier for a New Radio (5G) base station and an identifier for an anchor LTE base station for the New Radio base station.

Operation 530 includes determining, by the serving LTE base station based on the identifier for the New Radio base station, that the serving LTE base station does not have an interface to the New Radio base station. Operation 540 includes obtaining, by the serving LTE base station based on communication between the serving LTE base station and the anchor LTE base station via a core network, an address of the New Radio base station. And, operation 550 includes establishing, by the serving LTE base station based on the address of the New Radio base station, an interface with the New Radio base station for performing communications between the serving LTE base station and the New Radio base station.

[0093] Example 10. According to an example implementation of the method of example 9, the New Radio base station is configured for communication with the anchor LTE base station, wherein being configured for communication comprises the New Radio base station either being configured with an address of the anchor LTE base station or having established an interface with the anchor LTE base station.

[0094] Example 1 1 . An apparatus comprising at least one processor and at least one memory including computer instructions, when executed by the at least one processor, cause the apparatus to perform a method of any of examples 9-10.

[0095] Example 12. An apparatus comprising means for performing the method of any of examples 9-10.

[0096] Example 13. FIG. 6 is a flow chart illustrating operation of a base station according to another example implementation. Operation 610 includes establishing a connection between a first base station of a first radio access technology and a user device. Operation 620 includes receiving, by the user device, information transmitted from a second base station of a second radio access technology including an identifier for the second base station and an identifier for an anchor base station for the second base station, the anchor base station being of the first radio access technology. Operation 630 includes sending, by the user device to the first base station, a measurement report including the identifier for the second base station and the identifier for the anchor base station for the second base station.

[0097] Example 14. The method of example 13, wherein: the first base station comprises a serving Long Term Evolution (LTE) base station; the second base station comprises a New Radio (5G) base station; and the anchor base station comprises an anchor LTE base station for the New Radio base station, wherein the New Radio base station has been configured for communication with the anchor LTE base station, including the New Radio base station either being configured with an address of the anchor LTE base station or having established an interface with the anchor LTE base station.

[0098] Example 15. The method of example 14 wherein the sending comprises: sending, by the user device to the serving LTE base station, a measurement report including an identifier for a New Radio (5G) base station and an identifier for an anchor LTE base station for the New Radio base station, to allow the serving LTE base station to obtain a transport network layer address of the New Radio base station via the anchor LTE base station.

[0099] Example 16. The method of any of examples 14-15 wherein the identifier for the New Radio (5G) base station comprises at least one of: a first cell identifier, including at least one of a first physical cell identifier (PCI) and a first EUTRAN cell group identifier (ECGI), that identifies a cell associated with the New Radio (5G) base station; and a base station identifier (gNB identifier) that identifies the New Radio base station; and wherein the identifier for the anchor Long Term Evolution (LTE) base station comprises at least one of: a second cell identifier, including at least a second EUTRAN cell group identifier (ECGI), that identifies a cell associated with the anchor LTE base station; and a base station identifier (eNB identifier) that identifies the anchor LTE base station.

[00100] Example 17. An apparatus comprising at least one processor and at least one memory including computer instructions, when executed by the at least one processor, cause the apparatus to perform a method of any of examples 13-16.

[00101] Example 18. An apparatus comprising means for performing the method of any of examples 13-16.

[00102] Example 19. FIG. 7 is a flow chart illustrating operation of a base station according to another example implementation. Operation 710 includes transmitting, by a first base station of a first radio access technology, an identifier for the first base station and an identifier for an anchor base station of the first base station, the anchor base station being of a second radio access technology, wherein the first base station is configured for

communication with the anchor base station.

[00103] Example 20. According to an example implementation of the method of example 19, the first base station comprises a New Radio (5G) base station; and the anchor base station comprises an anchor Long Term Evolution (LTE) base station, wherein the New Radio base station has been configured for communication with the anchor LTE base station, including the New Radio base station either being configured with an address of the anchor LTE base station or having established an interface with the anchor LTE base station.

[00104] Example 21 . According to an example implementation of the method of example 20, further including establishing, based on a discovery of the New Radio base station via the transmission of the identifier for the New Radio base station and the identifier for the anchor LTE base station, an interface for communicating with another LTE base station.

[00105] Example 22. According to an example implementation of the method of any of examples 20-21 , wherein the identifier for the New Radio base station comprises at least one of: a first cell identifier, including at least one of a first physical cell identifier (PCI) and a first EUTRAN cell group identifier (ECGI), that identifies a cell associated with the New Radio (5G) base station; and a base station identifier (gNB identifier) that identifies the New Radio base station; and wherein the identifier for the anchor Long Term Evolution (LTE) base station comprises at least one of: a second cell identifier, including at least one of a second physical cell identifier (PCI) and a second EUTRAN cell group identifier (ECGI), that identifies a cell associated with the anchor LTE base station; and a base station identifier (eNB identifier) that identifies the anchor LTE base station.

[00106] Example 23. An apparatus comprising at least one processor and at least one memory including computer instructions, when executed by the at least one processor, cause the apparatus to perform a method of any of examples 19-22.

[00107] Example 24. An apparatus comprising means for performing the method of any of examples 19-22.

[00108] Example 25. FIG. 8 is a flow chart illustrating operation of a base station according to another example implementation. Operation 810 includes establishing a communication interface, by a serving Long Term Evolution (LTE) base station, with a New Radio (5G) base station via an anchor LTE base station for the New Radio base station based on an identifier for the anchor LTE base station that is broadcast by the New Radio base station, wherein the New Radio base station is configured for communication with the anchor LTE base station including the New Radio base station either being configured with an address of the anchor LTE base station or having established an interface with the anchor LTE base station.

[00109] Example 26. FIG. 9 is a flow chart illustrating operation of a base station according to another example implementation. Operation 910 includes establishing, by a first base station of a first radio access technology, a connection between the first base station and a user device. Operation 920 includes receiving, by the first base station from the user device, a measurement report including an identifier for a second base station of a second radio access technology. Operation 930 includes determining, by the first base station based on the identifier for the second base station, that the first base station does not have a communications interface to the second base station. Operation 940 includes sending, by the first base station to the user device, an access request including an identifier of the second base station to which a random access procedure should be performed to cause the user device to provide an identifier of the first base station to the second base station via a random access procedure performed by the user device with the second base station. And, operation 950 includes receiving, by the first base station from the second base station, a request to establish an interface for communication between the first base station and the second base station.

[00110] Example 27. According to an example implementation of the example 26, the first base station comprises a serving Long Term Evolution (LTE) base station; and the second base station comprises a New Radio (5G) base station.

[00111 ] Example 28. According to an example implementation of the method of example 27, wherein the identifier for the New Radio (5G) base station comprises at least one of: a first cell identifier, including at least one of a first physical cell identifier (PCI) and a first EUTRAN cell group identifier (ECGI), that identifies a cell associated with the New Radio base station; and a base station identifier (gNB identifier) that identifies the New Radio base station; and wherein the identifier for the serving Long Term Evolution (LTE) base station comprises at least one of: a second cell identifier, including at least one of a second physical cell identifier (PCI) and a second EUTRAN cell group identifier (ECGI), that identifies a cell associated with the serving LTE base station; and a base station identifier (eNB identifier) that identifies the serving LTE base station.

[00112] Example 29. An apparatus comprising at least one processor and at least one memory including computer instructions, when executed by the at least one processor, cause the apparatus to perform a method of any of examples 26-28.

[00113] Example 30. An apparatus comprising means for performing the method of any of examples 26-28.

[00114] Example 31 . FIG. 10 is a flow chart illustrating operation of a base station according to another example implementation. Operation 1010 includes establishing a communication interface, by a serving Long Term Evolution (LTE) base station with a New Radio (5G) base station, based on a New Radio access request message, sent by the serving LTE base station to a user device that has reported an identifier of the New Radio base station, the New Radio access request message instructing the user device to perform a random access procedure with New Radio and provide an identifier of the serving LTE base station to the New Radio base station via the random access procedure.

[00115] Example 32. FIG. 1 1 is a flow chart illustrating operation of a base station according to another example implementation. Operation 1 1 10 includes establishing a connection between a user device and a first base station of a first radio access technology. Operation 1 120 includes sending, by the user device to the first base station, a measurement report including an identifier for a second base station of a second radio access technology. Operation 1 130 includes receiving, by the user device from the first base station, an access request including an identifier of the second base station to which a random access procedure should be performed to cause the user device to provide an identifier of the first base station to the second base station via a random access procedure. Operation 1 140 includes providing, by the user device, an identifier of the first base station to the second base station via a random access procedure.

[00116] Example 33. According to an example implementation of the method of example 32, the first base station comprises a serving Long Term Evolution (LTE) base station; and the second base station comprises a New Radio (5G) base station.

[00117] Example 34. According to an example implementation of the method of example 33, wherein the providing comprises: providing an identifier of the serving LTE base station to the New Radio base station via a random access procedure to allow the New Radio base station to receive, from the New Radio base station via an anchor LTE base station, an address of the serving LTE base station based on the identifier of the serving LTE base station.

[00118] Example 35. According to an example implementation of the method of any of examples 33-34, wherein the identifier for the New Radio (5G) base station comprises at least one of: a first cell identifier, including at least one of a first physical cell identifier (PCI) and a first EUTRAN cell group identifier (ECGI), that identifies a cell associated with the New Radio base station; and a base station identifier (gNB identifier) that identifies the New Radio base station; and wherein the identifier for the serving Long Term Evolution (LTE) base station comprises at least one of: a second cell identifier, including at least one of a second physical cell identifier (PCI) and a second EUTRAN cell group identifier (ECGI), that identifies a cell associated with the serving LTE base station; and a base station identifier (eNB identifier) that identifies the serving LTE base station. [00119] Example 36. An apparatus comprising at least one processor and at least one memory including computer instructions, when executed by the at least one processor, cause the apparatus to perform a method of any of examples 32-35.

[00120] Example 37. An apparatus comprising means for performing the method of any of examples 32-35.

[00121 ] Example 38. FIG. 12 is a flow chart illustrating operation of a base station according to an example implementation. Operation 1210 includes transmitting, by a first base station of a first radio access technology, an identifier for the first base station, wherein the first base station is configured for communication with an anchor base station of a second radio access technology. Operation 1220 includes receiving, by the first base station from a user device via a random access procedure, an identifier of a second base station of the second radio access technology. Operation 1230 includes sending, by the first base station to the anchor base station, an address request for the second base station, the address request including the identifier for the second base station. Operation 1240 includes receiving, by the first base station from the anchor base station, the address of the second base station. And, operation 1250 includes establishing, by the first base station based on the received address of the second base station, an interface for communicating with the second base station.

[00122] Example 39. According to an example implementation of the method of example 38, the first base station comprises a New Radio (5G) base station; the anchor base station comprises an anchor Long Term Evolution (LTE) base station; and the second base station comprises a first LTE base station.

[00123] Example 40. According to an example implementation of the method of example 39, wherein other LTE base stations may communicate with the New Radio base station via the anchor LTE base station for the New Radio base station, and wherein the New Radio base station may communicate with a core network or one or more other LTE base stations through the anchor LTE base station.

[00124] Example 41 . According to an example implementation of any of examples 39- 40, wherein the identifier for the New Radio base station comprises at least one of: a first cell identifier, including at least one of a first physical cell identifier (PCI) and a first EUTRAN cell group identifier (ECGI), that identifies a cell associated with the New Radio (5G) base station; and a base station identifier (gNB identifier) that identifies the New Radio base station; and wherein the identifier for the first Long Term Evolution (LTE) base station comprises at least one of: a second cell identifier, including at least one of a second physical cell identifier (PCI) and a second EUTRAN cell group identifier (ECGI), that identifies a cell associated with the first LTE base station; and a base station identifier (eNB identifier) that identifies the first LTE base station.

[00125] Example 42. An apparatus comprising at least one processor and at least one memory including computer instructions, when executed by the at least one processor, cause the apparatus to perform a method of any of examples 38-41 .

[00126] Example 43. An apparatus comprising means for performing the method of any of examples 38-41 .

[00127] Example 44. FIG. 13 is a flow chart illustrating operation of a base station according to another example implementation. Operation 1310 includes establishing a connection between a first secondary base station of a first radio access technology and a user device, the first connection being part of a dual connectivity for the user device where the user device is connected via the first connection to the first secondary base station and is connected via a second connection to a master base station of a second radio access technology. Operation 1320 includes receiving, by the first secondary base station from the user device, a measurement report including an identifier for a second secondary base station of the first radio access technology and an identifier for an anchor base station for the second secondary base station, the anchor base station being of the second radio access technology, wherein both the first secondary base station and the second secondary base station are each configured for communication with the anchor base station;. Operation 1330 includes obtaining, by the first secondary base station from the anchor base station, an address of the second secondary base station based on the identifier for the second secondary base station. And, operation 1340 includes sending, by the first secondary base station to the master base station, a secondary base station change request, including the address of the second secondary base station, to request the master base station to change the secondary base station for the dual connectivity of the user device from the first secondary base station to the second secondary base station.

[00128] Example 45. According to an example implementation of the method of example 44: the first secondary base station comprises a source New Radio (5G) base station; the second secondary base station comprises a target New Radio (5G) base station; the anchor base station comprises a Long Term Evolution (LTE) anchor base station; and the master base station comprises a master LTE base station.

[00129] Example 46: According to an example implementation of the method of example 44: wherein both the first secondary base station and the second secondary base station being configured for communication with the anchor base station comprises each of the first secondary base station and the second secondary base station being at least one of the following: being configured with an address of the anchor base station; and having established an interface with the anchor base station.

[00130] Example 47. An apparatus comprising at least one processor and at least one memory including computer instructions, when executed by the at least one processor, cause the apparatus to perform a method of any of examples 44-46.

[00131] Example 48. An apparatus comprising means for performing the method of any of examples 44-46.

[00132] FIG. 14 is a block diagram of a wireless station (e.g., AP, BS, eNB, UE or user device) 1400 according to an example implementation. The wireless station 1400 may include, for example, one or two RF (radio frequency) or wireless transceivers 1402A, 1402B, where each wireless transceiver includes a transmitter to transmit signals and a receiver to receive signals. The wireless station also includes a processor or control unit/entity

(controller) 1404 to execute instructions or software and control transmission and receptions of signals, and a memory 1406 to store data and/or instructions.

[00133] Processor 1404 may also make decisions or determinations, generate frames, packets or messages for transmission, decode received frames or messages for further processing, and other tasks or functions described herein. Processor 1004, which may be a baseband processor, for example, may generate messages, packets, frames or other signals for transmission via wireless transceiver 1402 (1402A or 1402B). Processor 1404 may control transmission of signals or messages over a wireless network, and may control the reception of signals or messages, etc., via a wireless network (e.g., after being down- converted by wireless transceiver 1402, for example). Processor 1404 may be

programmable and capable of executing software or other instructions stored in memory or on other computer media to perform the various tasks and functions described above, such as one or more of the tasks or methods described above. Processor 1404 may be (or may include), for example, hardware, programmable logic, a programmable processor that executes software or firmware, and/or any combination of these. Using other terminology, processor 1404 and transceiver 1402 together may be considered as a wireless

transmitter/receiver system, for example.

[00134] In addition, referring to FIG. 14, a controller (or processor) 1408 may execute software and instructions, and may provide overall control for the station 1400, and may provide control for other systems not shown in FIG. 14, such as controlling input/output devices (e.g., display, keypad), and/or may execute software for one or more applications that may be provided on wireless station 1400, such as, for example, an email program, audio/video applications, a word processor, a Voice over IP application, or other application or software.

[00135] In addition, a storage medium may be provided that includes stored

instructions, which when executed by a controller or processor may result in the processor 1404, or other controller or processor, performing one or more of the functions or tasks described above.

[00136] According to another example implementation, RF or wireless transceiver(s) 1402A/1402B may receive signals or data and/or transmit or send signals or data. Processor 1404 (and possibly transceivers 1402A/1402B) may control the RF or wireless transceiver 1402A or 1402B to receive, send, broadcast or transmit signals or data.

[00137] The embodiments are not, however, restricted to the system that is given as an example, but a person skilled in the art may apply the solution to other communication systems. Another example of a suitable communications system is the 5G concept. It is assumed that network architecture in 5G will be quite similar to that of the LTE-advanced. 5G is likely to use multiple input - multiple output (MIMO) antennas, many more base stations or nodes than the LTE (a so-called small cell concept), including macro sites operating in cooperation with smaller stations and perhaps also employing a variety of radio technologies for better coverage and enhanced data rates.

[00138] It should be appreciated that future networks will most probably utilise network functions virtualization (NFV) which is a network architecture concept that proposes virtualizing network node functions into "building blocks" or entities that may be operationally connected or linked together to provide services. A virtualized network function (VNF) may comprise one or more virtual machines running computer program codes using standard or general type servers instead of customized hardware. Cloud computing or data storage may also be utilized. In radio communications this may mean node operations may be carried out, at least partly, in a server, host or node operationally coupled to a remote radio head. It is also possible that node operations will be distributed among a plurality of servers, nodes or hosts. It should also be understood that the distribution of labour between core network operations and base station operations may differ from that of the LTE or even be nonexistent.

[00139] Implementations of the various techniques described herein may be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations of them. Implementations may implemented as a computer program product, i.e., a computer program tangibly embodied in an information carrier, e.g., in a

machine-readable storage device or in a propagated signal, for execution by, or to control the operation of, a data processing apparatus, e.g., a programmable processor, a computer, or multiple computers. Implementations may also be provided on a computer readable medium or computer readable storage medium, which may be a non-transitory medium.

Implementations of the various techniques may also include implementations provided via transitory signals or media, and/or programs and/or software implementations that are downloadable via the Internet or other network(s), either wired networks and/or wireless networks. In addition, implementations may be provided via machine type communications (MTC), and also via an Internet of Things (IOT).

[00140] The computer program may be in source code form, object code form, or in some intermediate form, and it may be stored in some sort of carrier, distribution medium, or computer readable medium, which may be any entity or device capable of carrying the program. Such carriers include a record medium, computer memory, read-only memory, photoelectrical and/or electrical carrier signal, telecommunications signal, and software distribution package, for example. Depending on the processing power needed, the computer program may be executed in a single electronic digital computer or it may be distributed amongst a number of computers.

[00141 ] Furthermore, implementations of the various techniques described herein may use a cyber-physical system (CPS) (a system of collaborating computational elements controlling physical entities). CPS may enable the implementation and exploitation of massive amounts of interconnected ICT devices (sensors, actuators, processors microcontrollers,...) embedded in physical objects at different locations. Mobile cyber physical systems, in which the physical system in question has inherent mobility, are a subcategory of cyber-physical systems. Examples of mobile physical systems include mobile robotics and electronics transported by humans or animals. The rise in popularity of smartphones has increased interest in the area of mobile cyber-physical systems. Therefore, various implementations of techniques described herein may be provided via one or more of these technologies.

[00142] A computer program, such as the computer program(s) described above, can be written in any form of programming language, including compiled or interpreted languages, and can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit or part of it suitable for use in a computing environment. A computer program can be deployed to be executed on one computer or on multiple computers at one site or distributed across multiple sites and interconnected by a

communication network.

[00143] Method steps may be performed by one or more programmable processors executing a computer program or computer program portions to perform functions by operating on input data and generating output. Method steps also may be performed by, and an apparatus may be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit).

[00144] Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer, chip or chipset. Generally, a processor will receive instructions and data from a read-only memory or a random access memory or both. Elements of a computer may include at least one processor for executing instructions and one or more memory devices for storing instructions and data. Generally, a computer also may include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto-optical disks, or optical disks. Information carriers suitable for embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor and the memory may be supplemented by, or incorporated in, special purpose logic circuitry.

[00145] To provide for interaction with a user, implementations may be implemented on a computer having a display device, e.g., a cathode ray tube (CRT) or liquid crystal display (LCD) monitor, for displaying information to the user and a user interface, such as a keyboard and a pointing device, e.g., a mouse or a trackball, by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback, e.g., visual feedback, auditory feedback, or tactile feedback; and input from the user can be received in any form, including acoustic, speech, or tactile input.

[00146] Implementations may be implemented in a computing system that includes a back-end component, e.g., as a data server, or that includes a middleware component, e.g., an application server, or that includes a front-end component, e.g., a client computer having a graphical user interface or a Web browser through which a user can interact with an implementation, or any combination of such back-end, middleware, or front-end components. Components may be interconnected by any form or medium of digital data communication, e.g., a communication network. Examples of communication networks include a local area network (LAN) and a wide area network (WAN), e.g., the Internet.

[00147] While certain features of the described implementations have been illustrated as described herein, many modifications, substitutions, changes and equivalents will now occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the various embodiments.