TRANSPORT OF RRC MESSAGES IN DUAL CONNECTIVITY COMMUNICATION

TECHNICAL FIELD

The present disclosure is related to communications, and more particularly to wireless communications and related methods and base stations.

BACKGROUND

E-UTRAN supports Dual Connectivity (DC) operation whereby a multiple Rx/Tx UE in RRC CONNECTED is configured to utilize radio resources provided by two distinct schedulers, located in two eNBs connected via a non-ideal backhaul over the X2 interface (see 3 GPP 36.300). eNBs involved in DC for a certain UE may assume two different roles: an eNB may either act as an MN (Master node) or as an SN (Secondary node). In DC, a UE is connected to one MN and one SN.

In LTE DC, the radio protocol architecture that a particular bearer uses depends on how the bearer is setup. Three bearer types exist: MCG (Master Cell Group) bearer, SCG (Secondary Cell Group) bearer and split bearers. RRC is located in MN and SRBs (Signaling Radio Bearers) are always configured as MCG bearer type and therefore only use the radio resources of the MN.

Figure 1 is a block diagram illustrating a Long Term Evolution (LTE) DC User Plane (UP).

LTE-NR (New Radio) DC (also referred to as LTE-NR tight interworking) is currently being discussed for rel-15. In this context, significant changes from LTE DC include:

• The introduction of split bearer from the SN (known as SCG split bearer);

• The introduction of split bearer for RRC; and

· The introduction of a direct RRC from the SN.

Figures 2 and 3 illustrate the UP and Control Plane (CP) architectures for LTE-NR tight interworking.

Split RRC messages are mainly used to create diversity, and the sender can decide to either choose one of the links for scheduling the RRC messages, or it can duplicate the message over both links. SUMMARY

According to some embodiments of inventive concepts, a method may support dual connectivity (DC) communication for a wireless terminal using first and second base stations. Transmission of a Radio Resource Control (RRC) transport message may be initiated from the first base station to the second base station. The RRC transport message may include an identification of the wireless terminal and an RRC message related to the wireless terminal. The RRC transport message may be transmitted to the second base station using the Stream Control Transmission Protocol, SCTP.

According to some other embodiments of inventive concepts, a method may support dual connectivity (DC) communication for a wireless terminal using first and second base stations. A Radio Resource Control (RRC) transport message may be received at the first base station from the second base station. The RRC transport message may include an identification of the wireless terminal and an RRC message related to the wireless terminal. The RRC transport message may be received from the second base station using the Stream Control Transmission Protocol, SCTP.

According to some embodiments of inventive concepts, improved transport of RRC messages may be provided for a split radio bearer. A reliability of RRC transmission may thus be improved.

BRIEF DESCIRPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this application, illustrate certain non-limiting embodiments of inventive concepts. In the drawings:

Figure 1 is a block diagram illustrating a Long Term Evolution (LTE) User Plane (UP);

Figure 2 is a block diagram illustrating LTE - New Radio (NR) tight interworking UP;

Figure 3 is a block diagram illustrating LTE - NR tight interworking Control Plane (CP);

Figure 4 illustrates transport network layers for data streams over X2 from 3 GPP TS

36.424;

Figure 5 illustrates transport network layers for control plane signaling over X2 from 3 GPP TS 36.422; Figures 6A and 6B illustrate RRC transport procedures according to some embodiments of inventive concepts;

Figure 7 illustrates elements of an RRC transport message according to some embodiments of inventive concepts;

Figure 8 is a block diagram illustrating a wireless terminal (UE) according to some embodiments of inventive concepts;

Figure 9 is a block diagram of a network node according to some embodiments of inventive concepts;

Figures 10A and 10 B illustrate RRC transport procedures according to some additional embodiments of inventive concepts;

Figure 11 illustrates elements of a response message according to some embodiments of inventive concepts;

Figures 12 and 13 are flow charts illustrating network node operations according to some embodiments of inventive concepts; and

Figures 14 and 15 are flow charts illustrating wireless terminal operations according to some embodiments of inventive concepts.

DETAILED DESCRIPTION

Inventive concepts will now be described more fully hereinafter with reference to the accompanying drawings, in which examples of embodiments of inventive concepts are shown. Inventive concepts may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of present inventive concepts to those skilled in the art. It should also be noted that these embodiments are not mutually exclusive. Components from one embodiment may be tacitly assumed to be present/used in another embodiment.

The following description presents various embodiments of the disclosed subject matter. These embodiments are presented as teaching examples and are not to be construed as limiting the scope of the disclosed subject matter. For example, certain details of the described embodiments may be modified, omitted, or expanded upon without departing from the scope of the described subject matter. Figure 8 is a block diagram illustrating elements of a wireless terminal UE (also referred to as a wireless device, a wireless communication device, a wireless communication terminal, user equipment, a user equipment node/terminal/device, etc.) configured to provide wireless communication according to embodiments of inventive concepts. As shown, wireless terminal UE may include an antenna 807, and a transceiver circuit 801 (also referred to as a transceiver) including a transmitter and a receiver configured to provide uplink and downlink radio communications with a base station(s) of a radio access network. Wireless terminal UE may also include a processor circuit 803 (also referred to as a processor) coupled to the transceiver circuit, and a memory circuit 805 (also referred to as memory) coupled to the processor circuit. The memory circuit 805 may include computer readable program code that when executed by the processor circuit 803 causes the processor circuit to perform operations according to

embodiments disclosed herein. According to other embodiments, processor circuit 803 may be defined to include memory so that a separate memory circuit is not required. Wireless terminal UE may also include an interface (such as a user interface) coupled with processor 803, and/or wireless terminal UE may be incorporated in a vehicle.

As discussed herein, operations of wireless terminal UE may be performed by processor 803 and/or transceiver 801. For example, processor 803 may control transceiver 801 to transmit communications through transceiver 801 over a radio interface to another UE and/or to receive communications through transceiver 801 from another UE over a radio interface. Moreover, modules may be stored in memory 805, and these modules may provide instructions so that when instructions of a module are executed by processor 803, processor 803 performs respective operations (e.g., operations discussed below with respect to Example Embodiments).

Figure 9 is a block diagram illustrating elements of a node (also referred to as a network node, base station, eNB, eNodeB, etc.) of a Radio Access Network (RAN) configured to provide cellular communication according to embodiments of inventive concepts. As shown, the network node may include a transceiver circuit 901 (also referred to as a transceiver) including a transmitter and a receiver configured to provide uplink and downlink radio communications with wireless terminals. The network node may include a network interface circuit 907 (also referred to as a network interface) configured to provide communications with other nodes (e.g., with other base stations) of the RAN. The network node may also include a processor circuit 903

(also referred to as a processor) coupled to the transceiver circuit, and a memory circuit 905 (also referred to as memory) coupled to the processor circuit. The memory circuit 905 may include computer readable program code that when executed by the processor circuit 903 causes the processor circuit to perform operations according to embodiments disclosed herein. According to other embodiments, processor circuit 903 may be defined to include memory so that a separate memory circuit is not required.

As discussed herein, operations of the network node may be performed by processor 903, network interface 907, and/or transceiver 901. For example, processor 903 may control transceiver 901 to transmit communications through transceiver 901 over a radio interface to one or more UEs and/or to receive communications through transceiver 901 from one or more UEs over a radio interface. Similarly, processor 903 may control network interface 907 to transmit communications through network interface 907 to one or more other network nodes and/or to receive communications through network interface from one or more other network nodes.

Moreover, modules may be stored in memory 905, and these modules may provide instructions so that when instructions of a module are executed by processor 903, processor 903 performs respective operations (e.g., operations discussed below with respect to Example Embodiments).

According to some other embodiments, the network node may be implemented as a control node without a transceiver. In such embodiments, transmission to a wireless terminal may be initiated by the network node so that transmission to the wireless terminal is provided through a network node including a transceiver, e.g., through a base station. According to embodiments where the network node is a base station including a transceiver, initiating transmission may include transmitting through the transceiver.

In LTE DC, the forwarding of data packets between the MN and SN is handled by using the X2 User plane protocol that employs GTP-U (3 GPP TS 36.425, 3 GPP TS 36.424).

Figure 4 illustrates a transport network layer for data streams over X2 (taken from 3 GPP TS 36.424). It is specified in 36.424 that:

For the split bearer option:

• the GTP-U (TS 29.281 ) protocol over UDP over IP shall be supported as the transport for the data stream of PDCP PDUs on the X2 interface. The GTP-U PDU includes a RAN Container with flow control information as specified in TS 36.425 which is carried in the GTP-U extension header. The transport bearer is identified by the GTP-U TEID (TS 29.281) and the IP address of the MeNB and SeNB respectively. There may be zero or one UL data stream and there is one DL data stream per E-RAB at the X2 interface;

o The DL data stream is used for DL data transmission from the MeNB to the

SeNB;

o The UL data stream is used for UL data transmission from the SeNB to the

MeNB;

• the packet processing function in the MeNB shall send downstream packets of a given E- RAB to the SeNB IP address (received in X2AP) associated to the DL transport bearer of that particular E-RAB. The packet processing function in the SeNB shall send upstream packets of a given E-RAB to the MeNB IP address (received in X2AP) associated to the UL transport bearer of that particular E-RAB;

• data forwarding may be performed by MeNB providing GTP-U TEID to receive the DL data forwarded by the SeNB.

For split SRBs, the same mechanism as above can be used. However, the transport of CP RRC messages have different requirements than that of UP data messages. Thus, just creating one more tunnel via GTP-U mapped for an SRB may not be sufficient, as GTP-U doesn't support reliability. However, reliability may be important for the transport of CP RRC messages as these messages may contain critical configuration information that will impact the behaviour of the UE/network.

In addition, sending the CP RRC messages over the same interface as the data may cause delay because the high priority CP messages may end up being blocked by the user plane traffic (which is likely to be much larger in size and also arrive at a higher rate compared to the CP data).

According to some embodiments of inventive concepts, the issue of transporting RRC messages that belong to a split SRB between the MN and SN may be addressed. This may be achieved by introducing a new message in the X2AP CP protocol which is based on SCTP and thus offers reliable transmission.

According to some embodiments of inventive concepts, advantages of using an X2 AP message rather than adopting the current mechanisms of forwarding packets between the MN and SN for split DRBs (i.e., MCG split and SCG split bearers) may include:

• Reliable transmission via the inherent support of X2AP for the SCTP protocol • Separation of CP and UP data transport, thereby reducing/avoiding blocking by user plane data and providing/guaranteeing a low latency delivery of the CP data.

Figure 5 illustrates a Transport network layer for control plane signaling over X2 (taken from 3 GPP TS 36.422)

Note:

• though the focus here is on the LTE-NR tight interworking case, some embodiments of inventive concepts may also be applicable to other DC cases such as between two NR nodes.

• A focus here is on the split RRC from the MN (i.e. as shown in Fig. 3, SRB1 and SRB2 being split). Whether the direct RRC from the SN (which we refer to as SRB3 henceforth) could be split or not is still under discussion in 3 GPP, but some embodiments of inventive concepts equally cover that case as well.

• Whether duplication or path selection is to be employed for split SRBs; whether it is up to network implementation or it should be specified and if the UL and DL behaviors are different are currently being discussed in 3 GPP. However, embodiments of inventive concepts are concerned about on how the message is transported over the X2 interface once a decision has been made to use the split leg for the concerned message, and thus it is applicable to all possible outcomes of those discussions.

• This disclosure refers to the interface between the MN and SN as X2, based on the

current interface definitions in LTE. For LTE-NR interworking and NR-NR interworking cases, the exact name for such an interface could end up being different (e.g. Xn instead of X2, with the corresponding XnAP protocol instead of X2AP). However, that will not impact the applicability of inventive concepts at all.

• MN and MeNB are used interchangeably

· SN and SeNB are used interchangeably

The present disclosure introduces two new procedures called "MN-to-SN RRC transport" and "SN-to-MN RRC transport" that will be used to transport RRC messages between the MN and SN, as illustrated in Figure 6. A purpose of these procedures is to transport split RRC messages between the master and secondary nodes.

From the MN to the SN (Figure 6a), this will be used

• To transport DL SRB 1 and SRB2 data that has been split (source RRC is MN) • To transport UL SRB3 data that has been split (this could be either UE initiated RRC messages that are destined to the SN's RRC, or responses to RRC messages previously received from the SN)

From the SN to the MN (Figure 6b), this will be used

· To transport DL SRB3 data that has been split (source RRC is SN)

• To transport UL SRBl and SRB2 data that has been split (this could be either UE

initiated RRC messages that are destined to the MN's RRC, or responses to RRC messages previously received from the MN)

Figure 6 illustrates an RRC transport procedure. When the MN/SN decides to employ RRC diversity and send a PDCP PDU that corresponds to an SRB message over the secondary link, it creates an "RRC transport" message and sends it to the SN/MN via the X2 AP. The contents of this message are shown in the table of Figure 7.

Currently three message types are defined in TS 36.423 section 9.2.13 and they are: "Initiating Message", "Successful Outcome", "Unsuccessful Outcome". For the RRC transport message we can either use the "Initiating Message" type or a new message type (e.g. "CP data transport") may be defined and used instead.

The MeNB/SeNB X2AP IDs are the IDs used to uniquely identify the UE over the X2 interface at the MN and SN.

The SRB-K ⁾ identifies to which SRB is this message is mapped to, and it can take values 1,2 or 3 corresponding to SRBl, SRB2, or SRB3 (where SRB3 is the direct SRB from the SN to the UE, assuming that could be split). Note that the values 1,2 and 3 are just exemplary values and any other three distinct values could be used instead.

The priority is an optional field that is used to indicate a priority that the receiver of this message (SN if the message was from the MN, and vice versa) applies for this message as compared to other messages. As an example, a MN can set this to Priority2 if the RRC message has been sent (or scheduled to be sent) also over the master leg (i.e. RRC duplication) and to Priority 1 if it is not scheduled to be sent over the master leg. When the SN gets this message, if it is an overload situation in the DL, it can give messages with Priorityl over those that have Priority2. Other values might also be used to create more granularity and hence more scheduling differentiation. The Data contains the PDCP PDU that is corresponding to the RRC message. When the PDCP gets an SRB data, it adds a PDCP header (1 byte) as well as a MAC-I element for integrity verification (4 bytes long) [3 GPP 36.323). The maximum PDCP SDU size in LTE (as of rel-14) is 8188 bytes, thus the MAX PDCP PDU SIZE corresponding to that will be 8188+4+1=8193 bytes. This should be seen as an indication rather than an absolute limit to the size of the value as the PDCP SDU size might be increased and/or the PDCP header as well as the MAC-I size may change and/or additional IEs may be introduced in the PDCP PDU.

Most of the description above is targeted to the DL (i.e. MN SRB 1/2 data split and sent via the SN towards the UE, or SN SRB3 data split and sent via the MN towards the UE). The sender in this case has all the information it needs to make the corresponding RRC transport (i.e. it knows the concerned UE and as such the MeNB/SeNB X2AP IDs, the SRB -ID, priority, etc... )

In the UL, the situation is a little bit different. The corresponding cases are:

1. UE SRB 1/2 data destined for the MN is split and sent via the SN leg and arrives at the SN RLC. The RLC packet will arrive at the RLC entity corresponding to SRB 1/2 (this entity is setup/configured during the establishment/reconfiguration of the SN leg of the split SRBl/2). Since the SN knows from which entity this packet is arriving, it will know that the packet contains an SRB 1/2 data destined for the MN, and will set the SRB-K ⁾ that corresponds to SRB 1/2 when forming the SN-to-MN RRC transport message.

2. UE SRB3 data destined for the SN is split and sent via the MN leg and arrives at the MN RLC. The RLC packet will arrive at the RLC entity corresponding to SRB3 (this entity is setup/configured during the establishment/reconfiguration of the MN leg of the split SRB3). Since the MN knows from which entity this packet is arriving, it will know that the packet contains an SRB3 destined for the SN, and will set the SRB-K ⁾ that corresponds to SRB3 when forming the MN-to-SN RRC transport message.

The Priority information element may have more relevance in the DL case as compared to the UL because in the UL case, the data is sent over the X2 directly to the receiver node. In the DL case, on the other hand, the received message must be forwarded to the UE over a radio that is shared by several UEs. Also, the priority information may not be readily available in the UL case (e.g. in case 1 above, the SN may not be aware whether this data was duplicated on both legs or just sent over the SN leg of the split SRB 1/2). Figure 10 is a signaling diagram illustrating an alternative RRC transport procedure according to some embodiments of inventive concepts. The main difference from the procedure of Figure 6 is that here there is an optional response to the message. An example realization of this optional response message is shown in the table of Figure 11. In Figures 10A and 10B, the "RRC Transport Request" (also referred to as an "RRC transport request message") may be the same as the "RRC Transport" of Figure 6.

The sender node (i.e., the node that sends the RRC transport request message) can set the message type in the outgoing MN-to-SN or SN-to-MN message to "Initiating message", and the receiver node (i.e., the node that receives the RRC transport request message) can respond with either a positive (successful) or negative (unsuccessful) response with the message as above with the message type:

• set as "Successful operation" if the receiver node (i.e., the node that received the RRC transport request message) can execute the transport of the included RRC message to the UE or

· set as "Unsuccessful operation" if the receiver node (i.e., the node that received the RRC transport request message) was not able to execute the transport of the included RRC message to the UE

If it was an "Unsuccessful operation", the reason for the failure can be included in the Failure Cause information element.

An advantage of this alternative way of providing an RRC message transport procedure is that it could provide information to the sender node that may not be available at the sender node when the sender node has decided to route the RRC data via the receiver node. As an example, the MN may have decided to send the RRC message via the SN leg because a measurement report from the UE has indicated that the radio conditions between the UE and the SN are more favorable than that between the UE and MN. However, this may not provide information about the load situation at the SN, and the SN might not be able to send the data to the UE, despite the good radio conditions, because it is overloaded. By receiving a response message indicating that (e.g., the overload condition), the MN may decide to send the pending and future RRC messages via the MN leg instead. Instead of using of one message with two possible message types, another option is to use separate messages, for example, MN-to-SN/SN-to-MN RRC transport Acknowledge for successful operation and MN-to-SN/SN-to-MN RRC transport failure for unsuccessful operation.

It may be required to respond to both successful and unsuccessful operation, or only unsuccessful operation could be reported.

It should be noted that a positive response may be sent back immediately on the reception of the request (for example, if the receiver sees that the load in the system is very low), or it could be after the RRC message has been successful transmitted to the UE or it could even be after acknowledgements for the RLC packets corresponding to the forwarded message are received from the UE, signifying the message has arrived at the UE.

Similarly, a negative response can be sent back immediately on the reception of the request (for example, if the receiver sees that the load in the system is very high), or it could be after noticing the RRC message has not been successfully transmitted to the UE (e.g. within a certain time) or it could even be after receiving negative acknowledgements for the RLC packets corresponding to the forwarded message (e.g. even after maximum retransmission at the RLC level have been tried), signifying the message has not been received at the UE.

In all the above description, we focused only on the split RRC case. However, the invention is equally applicable to sending embedded RRC messages from the SN via the MN to the UE. This is needed when, for example,

· direct SRB (SRB3) is not available/configured between the SN and UE, or/and

• some coordination is needed between the MN and SN, and the RRC of the MN has to add some additional configuration for the MN leg as well

If direct SRB (SRB3) is not configured, the SRB-ID value of 3 may be used for this case as well. When the MN gets an SN-to-MN RRC transport message with SRB-K ⁾ value of 3 and SRB3 has not been configured, it will know that this is referring to an embedded SRB message and constructs a new MN RRC message that contains the received RRC message in a container. This message may contain nothing but the received RRC message or as mentioned above, the MN may add additional information relevant to the MN leg as well. When the RRC of the UE corresponding to the MN receives this message, it can extract the embedded RRC message and forwards it to the other RRC entity in the UE corresponding to the SN. If, on the other hand, SRB3 is available but an embedded RRC is to be sent because coordination is required between the MN and SN, then an ID other than 1..3 (e.g. 4) may be used. The behavior of the MN and the UE will be the same as in the previous case described above when SRB-ID 3 was employed.

It should be noted that, even if SRB3 is not available, another ID-value (e.g. 4) can be used for the sake of simplicity (i.e., when the MN gets an SN-to-MN RRC transport message with SRB-K ⁾ of 4, it knows this is an RRC message to be embedded and sent in a MN RRC message, regardless of the setup/configuration of SRB3).

Operations of a first base station (e.g., the network node of Figure 9) will now be discussed with reference to the flow chart of Figure 12 according to some embodiments of inventive concepts supporting dual connectivity (DC) communication for a wireless terminal using the first base station and a second base station. For example, modules may be stored in memory 905 of Figure 9, and these modules may provide instructions so that when the instructions of a module are executed by processor 903, processor 903 performs respective operations of the flow chart of Figure 12.

At block 1201, processor 903 of the first base station may receive an outer RRC message from the wireless terminal through transceiver 901, wherein an inner RRC message is embedded in the outer RRC message. Moreover, the inner RRC message may be an RRC message related to the wireless terminal.

At block 1203, processor 903 of the first base station may extract the inner RRC message from the outer RRC message responsive to receiving the outer RRC message with the inner RRC message embedded therein.

At block 1205, processor 903 of the first base station may initiate transmission of a Radio Resource Control (RRC) transport message through network interface 907 to the second base station. The RRC transport message may include an identification of the wireless terminal and the inner RRC message that was embedded in the outer RRC message. The RRC transport message may be transmitted to the second base station using the Stream Control Transmission Protocol, SCTP.

The RRC transport message may include a data portion that includes the inner RRC message. Moreover, the data portion may include a Packet Data Convergence Protocol (PDCP) Packet Data Unit (PDU) that includes a PDCP header and a PDCP Service Data Unit (SDU) that includes the RRC message.

The identification of the wireless terminal may include a first identification that uniquely identifies the wireless terminal at an X2 interface of the first base station and a second identification that uniquely identifies the wireless terminal at an X2 interface of the second base station.

The RRC transport message may include a Signaling Radio Bearer (SRB) identification (ID) that identifies an SRB to which the RRC message is mapped. Moreover, the SRB may be a split SRB having a first leg over a first radio interface between the first base station and the wireless terminal and a second leg over a second radio interface between the second base station and the wireless terminal.

Various operations of Figure 12 may be optional with respect to some embodiments. Regarding methods of example embodiment 1 (set forth below), for example, operations of blocks 1203 and 1205 of Figure 12 may be optional.

Operations of a first base station (e.g., the network node of Figure 9) will now be discussed with reference to the flow chart of Figure 13 according to some embodiments of inventive concepts supporting dual connectivity (DC) communication for a wireless terminal. For example, modules may be stored in memory 905 of Figure 9, and these modules may provide instructions so that when the instructions of a module are executed by processor 903, processor 903 performs respective operations of the flow chart of Figure 13.

At block 1301, processor 903 of the first base station may receive a Radio Resource Control (RRC) transport message from the second base station through network interface 907. Moreover, the RRC transport message may include an identification of the wireless terminal and an RRC message related to the wireless terminal. The RRC transport message may be received from the second base station using the Stream Control Transmission Protocol, SCTP. At block 1303, processor 903 of the first base station may embed the RRC message related to the wireless terminal in an outer RRC message responsive to receiving the RRC transport message including the RRC message related to the wireless terminal. At block 1305, processor 903 of the first base station may initiate transmission of the outer RRC message including the RRC message embedded therein through transceiver 901 to the wireless terminal. The RRC transport message of block 1301 may include a data portion comprising the RRC message. Moreover, the data portion may include a Packet Data Convergence Protocol (PDCP) Packet Data Unit (PDU) including a PDCP header and a PDCP Service Data Unit (SDU) including the RRC message.

The identification of the wireless terminal may include a first identification that uniquely identifies the wireless terminal at an X2 interface of the first base station and a second identification that uniquely identifies the wireless terminal at an X2 interface of the second base station.

The RRC transport message may include a Signaling Radio Bearer (SRB) identification (ID) that identifies an SRB to which the RRC message is mapped. Moreover, the SRB may be a split SRB having a first leg over a first radio interface between the first base station and the wireless terminal and a second leg over a second radio interface between the second base station and the wireless terminal.

Various operations of Figure 13 may be optional with respect to some embodiments. Regarding methods of example embodiment 33 (set forth below), for example, operations of blocks 1303 and 1305 of Figure 13 may be optional.

Operations of a wireless terminal UE (e.g., the wireless terminal of Figure 8) will now be discussed with reference to the flow chart of Figure 14 according to some embodiments of inventive concepts supporting dual connectivity (DC) communication using first and second base stations in a wireless communication network. For example, modules may be stored in memory 805 of Figure 8, and these modules may provide instructions so that when the instructions of a module are executed by processor 803, processor 803 performs respective operations of the flow chart of Figure 14.

At block 1401, processor 803 may receive an outer Radio Resource Control (RRC) message from the first base station through transceiver 801, wherein an inner RRC message is embedded in the outer RRC message. At block 1403, processor 803 may process the outer RRC message through a first protocol stack associated with the first base station to extract the inner RRC message responsive to receiving the outer RRC message. At block 1405, processor 803 may process the inner RRC message through at least a portion of a second protocol stack associated with the second base station responsive to extracting the inner RRC message. Processing the outer RRC message at block 1403 may include processing the outer RRC message through a first RRC layer of the first protocol stack associated with the first base station to extract the inner RRC message, and processing the inner RRC message at block 1405 may include processing the inner RRC message through a second RRC layer of the second protocol stack. Moreover, processing the inner RRC message through at least a portion of the second protocol stack may include processing the inner RRC message through the second RRC layer of the second protocol stack without processing the inner RRC message through a second PHY layer of the second protocol stack, without processing the inner RRC message through a second MAC layer of the second protocol stack, without processing the inner RRC message through a second RLC layer of the second protocol stack, and without processing the inner RRC message through a second PDCP layer of the second protocol stack.

The inner RRC message may be mapped to a Signaling Radio Bearer (SRB) including a radio link between the second base station and the wireless terminal. At block 1407, processor 803 may transmit data through transceiver 801 over a Data Radio Bearer (DRB) to the second base station based on the inner RRC message. At block 1409, processor 803 may receive data from the second base station over a Data Radio Bearer (DRB) based on the inner RRC message.

The inner RRC message may be mapped to a Signaling Radio Bearer (SRB) including a radio link between the second base station and the wireless terminal. At block 1411, processor 803 may perform a measurement based on the inner RRC message. At block 1413, processor 803 may transmit information based on the measurement through transceiver 801 to at least one of the first and second base stations. Moreover, transmitting the information may include transmitting the information through transceiver 801 to the second base station.

Various operations of Figure 14 may be optional with respect to some embodiments. Regarding methods of example embodiment 66 (set forth below), for example, operations of blocks 1407, 1409, 1411 and 1413 of Figure 14 may be optional.

Operations of a wireless terminal UE (e.g., the wireless terminal of Figure 8) will now be discussed with reference to the flow chart of Figure 15 according to some embodiments of inventive concepts supporting dual connectivity (DC) communication using first and second base stations in a wireless communication network. For example, modules may be stored in memory 805 of Figure 8, and these modules may provide instructions so that when the instructions of a module are executed by processor 803, processor 803 performs respective operations of the flow chart of Figure 15.

At block 1501, processor 803 may generate an inner Radio Resource Control (RRC) message. At block 1503, processor 803 may generate an outer RRC message, wherein the inner RRC message is embedded in the outer RRC message. At block 1505, processor 803 may transmit the outer RRC message with the inner RRC message embedded therein through transceiver 801 to the first base station.

Generating the outer RRC message at block 1503 may include generating the outer RRC message using a first RRC layer of a first protocol stack associated with the first base station, and generating the inner RRC message at block 1501 may include generating the inner RRC message using a second RRC layer of a second protocol stack associated with the second base station. Moreover, generating the inner RRC message may include generating the inner RRC message using the second RRC layer without using a second PDCP layer of the second protocol stack, without using a second RLC layer of the second protocol stack, without using a second MAC layer of the second protocol stack, and without using a second PHY layer of the second protocol stack.

In addition, the inner RRC message may be mapped to a Signaling Radio Bearer (SRB) including a radio link between the second base station and the wireless terminal.

Some example embodiments are discussed below.

1. A method supporting dual connectivity, DC, communication for a wireless terminal using first and second base stations, the method comprising: initiating transmission of a Radio Resource Control, RRC, transport message from the first base station to the second base station, wherein the RRC transport message includes an identification of the wireless terminal and an RRC message related to the wireless terminal.

2. The method of Embodiment 1, wherein RRC transport message includes a data portion comprising the RRC message.

3. The method of Embodiment 2 wherein the data portion comprises a Packet Data Convergence Protocol, PDCP, Packet Data Unit, DPU, including a PDCP header and a PDCP Service Data Unit, SDU, including the RRC message.

4. The method of any of Embodiments 1-3, wherein the identification of the wireless terminal includes a first identification that uniquely identifies the wireless terminal at an X2 interface of the first base station and a second identification that uniquely identifies the wireless terminal at an X2 interface of the second base station.

5. The method of Embodiment 4, wherein the first identification comprises a MeNB UE X2AP ID and the second identification comprises a SeNB UE X2AP ID.

6. The method of any of Embodiments 1-5 wherein the RRC transport message includes a Signaling Radio Bearer, SRB, identification, ID, that identifies an SRB to which the RRC message is mapped.

7. The method of Embodiment 6, wherein the SRB is a split SRB having a first leg over a first radio interface between the first base station and the wireless terminal and a second leg over a second radio interface between the second base station and the wireless terminal.

8. The method of any of Embodiments 1-7 wherein the RRC transport message includes a message type.

9. The method of Embodiment 8, wherein the message type indicates at least one of an initiating message and a Control Plane, CP, data transport message.

10. The method of any of Embodiments 1-9, wherein the RRC transport message includes a priority indicator to indicate to the second base station a priority to apply to the RRC message related to the wireless terminal.

11. The method of Embodiment 10, wherein the priority indicator is set to one of a high priority responsive to determining that the RRC message is to be transmitted to the wireless terminal from the second base station and not from the first base station, and a low priority responsive to determining that the RRC message is to be transmitted to the wireless terminal from both of the first and second base stations.

12. The method of any of Embodiments 1-11 further comprising: initiating transmission of the RRC message from the first base station to the wireless terminal.

13. The method of any of Embodiments 1-12 wherein initiating transmission of the RRC transport message comprises initiating transmission of the RRC transport message responsive to generating the RRC message related to the wireless terminal for transmission to the wireless terminal.

14. The method of any of Embodiments 1-10 wherein initiating transmission of the RRC transport message comprises initiating transmission of the RRC transport message responsive to receiving the RRC message from the wireless terminal. 15. The method of any of Embodiments 1-14, further comprising: receiving a response at the first base station from the second base station, wherein the response corresponds to the RRC transport message.

16. The method of Embodiment 15, wherein the response indicates successful operation at the second base station relating to the RRC transport message.

17. The method of Embodiment 15, wherein the response indicates unsuccessful operation at the second base station relating to the RRC transport message.

18. The method of Embodiment 17 further comprising: responsive to receiving the response indicating unsuccessful operation at the second base station, initiating transmission of the RRC message from the first base station to the wireless terminal.

19. The method of any of Embodiments 17-18, wherein the response includes a failure cause.

20. The method of Embodiment 19 wherein the failure cause indicates an overload condition at the second base station.

21. The method of any of Embodiments 15-20, wherein the response includes at least one of an identification that uniquely identifies the wireless terminal at an X2 interface of the first base station, an identification that uniquely identifies the wireless terminal at an X2 interface of the second base station, and a Signaling Radio Bearer, SRB, identification, ID, that identifies an SRB to which the RRC message is mapped.

22. The method of any of Embodiments 1-10 and 14-21, wherein the RRC message related to the wireless terminal is an inner RRC message, the method further comprising:

receiving an outer RRC message from the wireless terminal at the first base station, wherein the inner RRC message is embedded in the outer RRC message; and responsive to receiving the outer RRC message with the inner RRC message embedded therein, extracting the inner RRC message from the outer RRC message; wherein the RRC transport message includes the identification of the wireless terminal and the inner RRC message that was embedded in the outer RRC message.

23. The method of any of Embodiments 1-10 and 14-22, further comprising: receiving the RRC message from the wireless terminal at the first base station over a split signaling bearer; wherein initiating transmission of the RRC transport message comprises initiating transmission of the RRC transport message with the RRC message before/without processing the RRC message through a PDCP layer and/or an RLC layer of the first base station.

24. The method of any of Embodiments 1-23 wherein the first base station is a master base station and the second base station is a secondary base station.

25. The method of any of Embodiments 1-23 where the first base station is a secondary base station and the second base station is a master base station.

26. The method of any of Embodiments 1-5 and 8-25 wherein the RRC message is mapped to a split Signaling Radio Bearer, SRB, having a first signaling leg over a first signaling radio interface between the first base station and the wireless terminal and a second signaling leg over a second signaling radio interface between the second base station and the wireless terminal.

27. The method of Embodiment 26 further comprising: initiating transmission of data to the wireless terminal based on the RRC message, wherein the data is transmitted over a split Data Radio Bearer, DRB, having a first data leg over a first data radio interface between the first base station and the wireless terminal and a second data leg over a second data radio interface between the second base station and the wireless terminal.

28. The method of Embodiment 27 wherein initiating transmission of the data comprises at least one of: initiating transmission of the data from the first base station to the wireless terminal using the first data leg over the first data radio interface; and initiating transmission of the data from the first base station through the second base station to the wireless terminal using the second data leg over the second data radio interface.

29. The method of Embodiment 26 further comprising: receiving data from the wireless terminal based on the RRC message, wherein the data is received over a split Data Radio Bearer, DRB, having a first data leg over a first data radio interface between the first base station and the wireless terminal and a second data leg over a second data radio interface between the second base station and the wireless terminal.

30. The method of Embodiment 29 wherein receiving the data comprises at least one of: receiving the data at the first base station from the wireless terminal using the first data leg over the first data radio interface; and receiving the data at the first base station from the wireless terminal through the second base station using the second data leg over the second data radio interface. 31. The method of any of Embodiments 1-30 wherein the RRC transport message is transmitted to the second base station using the Stream Control Transmission Protocol, SCTP.

32. The method of any of Embodiments 1-31 wherein initiating transmission includes transmitting the RRC transport message from the first base station to the second base station.

33. A method supporting dual connectivity, DC, communication for a wireless terminal using first and second base stations, the method comprising: receiving a Radio Resource Control, RRC, transport message at the first base station from the second base station, wherein the RRC transport message includes an identification of the wireless terminal and an RRC message related to the wireless terminal.

34. The method of Embodiment 33, wherein RRC transport message includes a data portion comprising the RRC message.

35. The method of Embodiment 34 wherein the data portion comprises a Packet Data

Convergence Protocol, PDCP, Packet Data Unit, DPU, including a PDCP header and a PDCP

Service Data Unit, SDU, including the RRC message.

36. The method of any of Embodiments 33-35, wherein the identification of the wireless terminal includes a first identification that uniquely identifies the wireless terminal at an X2 interface of the first base station and a second identification that uniquely identifies the wireless terminal at an X2 interface of the second base station.

37. The method of Embodiment 36, wherein the first identification comprises a MeNB UE X2AP ID and the second identification comprises a SeNB UE X2AP ID.

38. The method of any of Embodiments 33-37 wherein the RRC transport message includes a Signaling Radio Bearer, SRB, identification, ID, that identifies an SRB to which the RRC message is mapped.

39. The method of Embodiment 38, wherein the SRB is a split SRB having a first leg over a first radio interface between the first base station and the wireless terminal and a second leg over a second radio interface between the second base station and the wireless terminal.

40. The method of any of Embodiments 33-39 wherein the RRC transport message includes a message type.

41. The method of Embodiment 40, wherein the message type indicates at least one of an initiating message and a Control Plane, CP, data transport message. 42. The method of any of Embodiments 33-41, wherein the RRC transport message includes a priority indicator to indicate a priority to apply to the RRC message related to the wireless terminal.

43. The method of Embodiment 42, wherein the priority indicator is set to one of a high priority indicating that the RRC message is to be transmitted to the wireless terminal from the first base station and not from the second base station, and a low priority indicating that the RRC message is to be transmitted to the wireless terminal from both of the first and second base stations.

44. The method of any of Embodiments 33-43 further comprising: initiating transmission of the RRC message from the first base station to the wireless terminal.

45. The method of any of Embodiments 33-44, further comprising: initiating

transmission of a response from the first base station to the second base station, wherein the response corresponds to the RRC transport message.

46. The method of Embodiment 45, wherein the response indicates successful operation at the first base station relating to the RRC transport message.

47. The method of Embodiment 45, wherein the response indicates unsuccessful operation at the first base station relating to the RRC transport message.

48. The method of Embodiment 47, wherein the response includes a failure cause.

49. The method of Embodiment 48 wherein the failure cause indicates an overload condition at the first base station.

50. The method of any of Embodiments 45-49, wherein the response includes at least one of an identification that uniquely identifies the wireless terminal at an X2 interface of the first base station, an identification that uniquely identifies the wireless terminal at an X2 interface of the second base station, and a Signaling Radio Bearer, SRB, identification, ID, that identifies an SRB to which the RRC message is mapped.

51. The method of any of Embodiments 33-43 and 45-50 further comprising: responsive to receiving the RRC transport message including the RRC message related to the wireless terminal, embedding the RRC message related to the wireless terminal in an outer RRC message; and initiating transmission of the outer RRC message including the RRC message embedded therein from the first base station to the wireless terminal. 52. The method of any of Embodiments 33-43 and 45-50 further comprising: responsive to receiving the RRC transport message including the RRC message related to the wireless terminal, modifying the RRC message related to the wireless terminal to provide a modified RRC message related to the wireless terminal; embedding the modified RRC message related to the wireless terminal in an outer RRC message; and initiating transmission of the outer RRC message including the modified RRC message therein from the first base station to the wireless terminal.

53. The method of any of Embodiments 33-52 wherein the first base station is a master base station and the second base station is a secondary base station.

54. The method of any of Embodiments 33-52 where the first base station is a secondary base station and the second base station is a master base station.

55. The method of any of Embodiments 33-38 and 40-54 wherein the RRC message is mapped to a split Signaling Radio Bearer, SRB, having a first signaling leg over a first signaling radio interface between the first base station and the wireless terminal and a second signaling leg over a second signaling radio interface between the second base station and the wireless terminal.

56. The method of Embodiment 55 further comprising: initiating transmission of data to the wireless terminal based on the RRC message, wherein the data is transmitted over a split Data Radio Bearer, DRB, having a first data leg over a first data radio interface between the first base station and the wireless terminal and a second data leg over a second data radio interface between the second base station and the wireless terminal.

57. The method of Embodiment 56 wherein initiating transmission of the data comprises at least one of: initiating transmission of the data from the first base station to the wireless terminal using the first data leg over the first data radio interface; and initiating transmission of the data from the first base station through the second base station to the wireless terminal using the second data leg over the second data radio interface.

58. The method of Embodiment 55 further comprising: receiving data from the wireless terminal based on the RRC message, wherein the data is received over a split Data Radio Bearer, DRB, having a first data leg over a first data radio interface between the first base station and the wireless terminal and a second data leg over a second data radio interface between the second base station and the wireless terminal. 59. The method of Embodiment 58 wherein receiving the data comprises at least one of: receiving the data at the first base station from the wireless terminal using the first data leg over the first data radio interface; and receiving the data at the first base station from the wireless terminal through the second base station using the second data leg over the second data radio interface.

60. The method of any of Embodiments 33-59 wherein the RRC transport message is received over an X2 interface between the first and second base stations.

61. The method of any of Embodiments 33-60 wherein the RRC transport message is reeived from the second base station using the Stream Control Transmission Protocol, SCTP.

62. A network node comprising: a transceiver configured to provide wireless network communication with a wireless terminal; a network interface configured to provide network communication with other network nodes; and a processor coupled with the transceiver and the network interface, wherein the processor is configured to provide communication with the wireless terminal through the transceiver, wherein the processor is configured to provide communication with the other network nodes through the network interface, and wherein the processor is configured to perform operations according to any of Embodiments 1-61.

63. The network node of Embodiment 62 wherein the network interface is an X2 network interface.

64. A network node, wherein the network node is adapted to perform operations according to any of Embodiments 1-61.

65. A network node, wherein the network node includes modules configured to perform operations according to any of Embodiments 1-61.

66. A method of operating a wireless terminal supporting dual connectivity, DC, communication using first and second base stations in a wireless communication network, the method comprising: receiving an outer Radio Resource Control, RRC, message from the first base station, wherein an inner RRC message is embedded in the outer RRC message; responsive to receiving the outer RRC message, processing the outer RRC message through a first protocol stack associated with the first base station to extract the inner RRC message; and responsive to extracting the inner RRC message, processing the inner RRC message through at least a portion of a second protocol stack associated with the second base station. 67. The method of Embodiment 66, wherein processing the outer RRC message comprises processing the outer RRC message through a first RRC layer of the first protocol stack associated with the first base station to extract the inner RRC message, and wherein processing the inner RRC message comprises processing the inner RRC message through a second RRC layer of the second protocol stack.

68. The method of Embodiment 67, wherein processing the outer RRC message comprises processing the outer RRC message through a first PHY layer of the first protocol stack, a first MAC layer of the first protocol stack, a first RLC layer of the first protocol stack, a first PDCP layer of the first protocol stack, the first RRC layer of the first protocol stack.

69. The method of any of Embodiment 67-68, wherein processing the inner RRC message through at least a portion of the second protocol stack comprises processing the inner RRC message through the second RRC layer of the second protocol stack without processing the inner RRC message through a second PHY layer of the second protocol stack, without processing the inner RRC message through a second MAC layer of the second protocol stack, without processing the inner RRC message through a second RLC layer of the second protocol stack, and without processing the inner RRC message through a second PDCP layer of the second protocol stack.

70. The method of any of Embodiments 66-69, wherein the inner RRC message is mapped to a Signaling Radio Bearer, SRB, including a radio link between the second base station and the wireless terminal.

71. The method of Embodiment 70, wherein the SRB is a split SRB having a first signaling leg over a first signaling radio interface between the first base station and the wireless terminal and a second signaling leg over a second signaling radio interface between the second base station and the wireless terminal.

72. The method of any of Embodiments 70-71 further comprising:

transmitting data from the wireless terminal over a Data Radio Bearer, DRB, to the second base station based on the inner RRC message.

73. The method of any of Embodiments 72, wherein the DRB is a split DRB having a first data leg over a first data radio interface between the first base station and the wireless terminal and a second data leg over a second data radio interface between the second base station and the wireless terminal. 74. The method of Embodiment 73 wherein transmitting the data comprises at least one of: transmitting the data from the wireless terminal to the first base station using the first data leg over the first data radio interface; and transmitting the data from the wireless terminal to the second base station using the second data leg over the second data radio interface.

75. The method of any of Embodiment 70-71 further comprising: receiving data from the second base station over a Data Radio Bearer, DRB, based on the inner RRC message.

76. The method of any of Embodiments 75, wherein the DRB is a split DRB having a first data leg over a first data radio interface between the first base station and the wireless terminal and a second data leg over a second data radio interface between the second base station and the wireless terminal.

77. The method of Embodiment 76 wherein receiving the data comprises at least one of: receiving the data at the wireless terminal from the first base station using the first data leg over the first data radio interface; and receiving the data at the wireless terminal from first base station using the second data leg over the second data radio interface.

78. The method of any of Embodiments 66-77 wherein the first base station is a master base station and the second base station is a secondary base station.

79. The method of any of Embodiments 66-77 where the first base station is a secondary base station and the second base station is a master base station.

80. The method of any of Embodiments 66-79 further comprising: performing a measurement based on the inner RRC message; and transmitting information based on the measurement to at least one of the first and second base stations.

81. The method of Embodiment 80 wherein transmitting the information comprises transmitting the information to the second base station.

82. The method of any of Embodiment 80-81 wherein the measurement includes at least one of a signal quality measurement and/or a received signal power measurement.

83. A method of operating a wireless terminal supporting dual connectivity, DC, communication using first and second base stations in a wireless communication network, the method comprising: generating an inner Radio Resource Control, RRC, message; generating an outer RRC message, wherein the inner RRC message is embedded in the outer RRC message; and transmitting the outer RRC message with the inner RRC message embedded therein to the first base station. 84. The method of Embodiment 83 wherein generating the outer RRC message comprises generating the outer RRC message using a first RRC layer of a first protocol stack associated with the first base station.

85. The method of Embodiment 84 wherein generating the outer RRC message further comprises generating the outer RRC message using a first PDCP layer of the first protocol stack, using a first RLC layer of the first protocol stack, using a first MAC layer of the first protocol stack, and using a PHY layer of the first protocol layer.

86. The method of any of Embodiments 84-85, wherein generating the inner RRC message comprises generating the inner RRC message using a second RRC layer of a second protocol stack associated with the second base station.

87. The method of Embodiment 86, wherein generating the RRC message comprises generating the RRC message using the second RRC layer without using a second PDCP layer of the second protocol stack, without using a second RLC layer of the second protocol stack, without using a second MAC layer of the second protocol stack, and without using a second PHY layer of the second protocol stack.

88. The method of any of Embodiments 83-87, wherein the inner RRC message is mapped to a Signaling Radio Bearer, SRB, including a radio link between the second base station and the wireless terminal.

89. The method of Embodiment 88, wherein the SRB is a split SRB having a first signaling leg over a first signaling radio interface between the first base station and the wireless terminal and a second signaling leg over a second signaling radio interface between the second base station and the wireless terminal.

90. The method of any of Embodiments 88-89, further comprising: transmitting data from the wireless terminal over a Data Radio Bearer, DRB, to the second base station based on the inner RRC message.

91. The method of any of Embodiments 90, wherein the DRB is a split DRB having a first data leg over a first data radio interface between the first base station and the wireless terminal and a second data leg over a second data radio interface between the second base station and the wireless terminal.

92. The method of Embodiment 91 wherein transmitting the data comprises at least one of: transmitting the data from the wireless terminal to the first base station using the first data leg over the first data radio interface; and transmitting the data from the wireless terminal to the second base station using the second data leg over the second data radio interface.

93. The method of any of Embodiment 88-89 further comprising: receiving data from the second base station over a Data Radio Bearer, DRB, based on the inner RRC message.

94. The method of any of Embodiments 93 wherein the DRB is a split DRB having a first data leg over a first data radio interface between the first base station and the wireless terminal and a second data leg over a second data radio interface between the second base station and the wireless terminal.

95. The method of Embodiment 94 wherein receiving the data comprises at least one of: receiving the data at the wireless terminal from the first base station using the first data leg over the first data radio interface; and receiving the data at the wireless terminal from first base station using the second data leg over the second data radio interface.

96. The method of any of Embodiments 83-95 wherein the first base station is a master base station and the second base station is a secondary base station.

97. The method of any of Embodiments 83-95 where the first base station is a secondary base station and the second base station is a master base station.

98. A wireless terminal, UE, comprising: a transceiver configured to provide wireless communication in a wireless communication network; and a processor coupled with the transceiver, wherein the processor is configured to provide wireless network communication through the transceiver, wherein the processor is configured to perform operations according to any of Embodiments 66-97.

99. A wireless terminal, UE, wherein the wireless terminal is adapted to perform operations according to any of Embodiments 66-97.

100. A wireless terminal, UE, wherein the wireless terminal includes modules configured to perform operations according to any of Embodiments 66-97.

101. A network node comprising: a network interface configured to provide network communication with other network nodes; and a processor coupled with the network interface, wherein the processor is configured to provide communication with other network nodes through the network interface, and wherein the processor is configured to perform operations according to any of Embodiments 1 -61.

Definitions of some abbreviations are provided below. Abbreviation Explanation

AP Application Protocol

CP Control Plane

DC Dual Connectivity

DL Downlink

DRB Data Radio Bearer

E-RAB EUTRAN Radio Access Bearer

GTP-U GPRS Tunneling Protocol - User Plane

IP Internet Protocol

LTE Long Term Evolution

MCG Master Cell Group

MAC Medium Access Control

MeNB Master eNB

MN Master Node

NR New Radio

PDCP Packet Data Convergence Protocol

RLC Radio Link Control

RRC Radio Resource Control

SCG Secondary Cell Group

SCTP Stream Control Transmission Protocol

SeNB Secondary eNB

SN Secondary Node

SRB Signaling Radio Bearer

TEID Tunnel Endpoint IDentifier

TNL Transport Network Layer

UDP User Datagram Protocol

UE User Equipment

UL Uplink

UP User Plane

Further definitions and embodiments are discussed below. In the above-description of various embodiments of present inventive concepts, it is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of present inventive concepts. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which present inventive concepts belong. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

When an element is referred to as being "connected", "coupled", "responsive", or variants thereof to another element, it can be directly connected, coupled, or responsive to the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly connected", "directly coupled", "directly responsive", or variants thereof to another element, there are no intervening elements present. Like numbers refer to like elements throughout. Furthermore, "coupled", "connected", "responsive", or variants thereof as used herein may include wirelessly coupled, connected, or responsive. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. Well-known functions or constructions may not be described in detail for brevity and/or clarity. The term "and/or" includes any and all combinations of one or more of the associated listed items.

It will be understood that although the terms first, second, third, etc. may be used herein to describe various elements/operations, these elements/operations should not be limited by these terms. These terms are only used to distinguish one element/operation from another

element/operation. Thus a first element/operation in some embodiments could be termed a second element/operation in other embodiments without departing from the teachings of present inventive concepts. The same reference numerals or the same reference designators denote the same or similar elements throughout the specification.

As used herein, the terms "comprise", "comprising", "comprises", "include", "including", "includes", "have", "has", "having", or variants thereof are open-ended, and include one or more stated features, integers, elements, steps, components or functions but does not preclude the presence or addition of one or more other features, integers, elements, steps, components, functions or groups thereof. Furthermore, as used herein, the common abbreviation "e.g.", which derives from the Latin phrase "exempli gratia," may be used to introduce or specify a general example or examples of a previously mentioned item, and is not intended to be limiting of such item. The common abbreviation "i.e.", which derives from the Latin phrase "id est," may be used to specify a particular item from a more general recitation.

Example embodiments are described herein with reference to block diagrams and/or flowchart illustrations of computer-implemented methods, apparatus (systems and/or devices) and/or computer program products. It is understood that a block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, can be implemented by computer program instructions that are performed by one or more computer circuits. These computer program instructions may be provided to a processor circuit of a general purpose computer circuit, special purpose computer circuit, and/or other programmable data processing circuit to produce a machine, such that the instructions, which execute via the processor of the computer and/or other programmable data processing apparatus, transform and control transistors, values stored in memory locations, and other hardware components within such circuitry to implement the functions/acts specified in the block diagrams and/or flowchart block or blocks, and thereby create means (functionality) and/or structure for implementing the functions/acts specified in the block diagrams and/or flowchart block(s).

These computer program instructions may also be stored in a tangible computer-readable medium that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable medium produce an article of manufacture including instructions which implement the functions/acts specified in the block diagrams and/or flowchart block or blocks. Accordingly, embodiments of present inventive concepts may be embodied in hardware and/or in software (including firmware, resident software, micro-code, etc.) that runs on a processor such as a digital signal processor, which may collectively be referred to as "circuitry," "a module" or variants thereof.

It should also be noted that in some alternate implementations, the functions/acts noted in the blocks may occur out of the order noted in the flowcharts. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality /acts involved. Moreover, the functionality of a given block of the flowcharts and/or block diagrams may be separated into multiple blocks and/or the functionality of two or more blocks of the flowcharts and/or block diagrams may be at least partially integrated. Finally, other blocks may be added/inserted between the blocks that are illustrated, and/or blocks/operations may be omitted without departing from the scope of inventive concepts. Moreover, although some of the diagrams include arrows on communication paths to show a primary direction of communication, it is to be understood that communication may occur in the opposite direction to the depicted arrows.

Many variations and modifications can be made to the embodiments without substantially departing from the principles of the present inventive concepts. All such variations and modifications are intended to be included herein within the scope of present inventive concepts. Accordingly, the above disclosed subject matter is to be considered illustrative, and not restrictive, and the examples of embodiments are intended to cover all such modifications, enhancements, and other embodiments, which fall within the spirit and scope of present inventive concepts. Thus, to the maximum extent allowed by law, the scope of present inventive concepts are to be determined by the broadest permissible interpretation of the present disclosure including the examples of embodiments and their equivalents, and shall not be restricted or limited by the foregoing detailed description.