Patent Application
20250227662
The present disclosure relates generally to communications, and more particularly to communication methods and related devices and nodes supporting wireless communications.
In current standardization of sidelink relay, the remote user equipment (UE) sends a measurement report to the network, together with the channel-related measurements, e.g., Reference Signal Received Strength (RSRP), Reference Signal Received Quality (RSRQ), Signal to Interference Noise Ratio (SINR), etc., the remote UE reports also a list of candidate relay UEs that is used by the 5G radio base station (gNB) in order to select a relay UE over which the remote UE may perform path switch. There currently exists certain challenge(s). A problem arises if the gNB picks from the list of relay UEs a relay UE in a Radio Resource Control (RRC), RRC_IDLE/INACTIVE state over which the remote UE is to perform path switch. In this case, the relay UE needs to first transit to the RRC_CONNECTED state and later receive an RRC reconfiguration message from the gNB in order to accommodate the remote UE and relay the remote UEs traffic to the gNB. However, the relay UE is unaware that it has been chosen by the gNB as a target relay UE and thus in this case is not possible to complete the path switch procedure as the gNB cannot send any direct signaling to the relay UE because the relay UE does not have any active RRC connection towards the gNB.
Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges. Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges. The exemplary embodiments described herein allow the gNB, the remote UE, or a core network (CN) to be able to page the relay UE chosen as a target relay UE for the sidelink relay path switch procedure. Upon receiving the measurement report from the remote UE and if a relay UE in RRC_IDLE/INACTIVE has been selected as the target relay UE by the gNB, at least one (or a combination) of the following solutions can be applied:
Certain embodiments may provide one or more of the following technical advantage(s). When a candidate relay UE is selected as a target relay UE during the sidelink relay path switch procedure, the gNB, the remote UE, or the CN are able to page this UE and indicate that the UE should transit to RRC_CONNECTED in order to complete the sidelink relay path switch procedure. This will avoid that the path switch procedure is aborted when the target relay UE is in RRC_IDLE/INACTIVE. Additionally, the remote UE will not incur a long connectivity interruption due to the failed path switch procedure and the triggering of an RRC reestablishment procedure.
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:
Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art., 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.
As previously indicated, certain embodiments may provide one or more of the following technical advantage(s). When a candidate relay UE is selected as a target relay UE during the sidelink relay path switch procedure, the gNB, the remote UE, or the CN are able to page this UE and indicate that the UE should transit to RRC_CONNECTED in order to complete the sidelink relay path switch procedure. This will avoid that the path switch procedure is aborted when the target relay UE is in RRC_IDLE/INACTIVE. Additionally, the remote UE will not incur a long connectivity interruption due to the failed path switch procedure and the triggering of an RRC reestablishment procedure.
Sidelink transmissions over NR includes enhancements of the ProSe (PROximity-based SErvices) specified for Long-Term Evolution (LTE). Four new enhancements are particularly introduced to NR sidelink transmissions as follows:
To enable the above enhancements, new physical channels and reference signals are introduced in NR (available in LTE before.):
Another new feature is the two-stage sidelink control information (SCI). This a version of the DCI for SL. Unlike the DCI, only part (first stage) of the SCI is sent on the PSCCH. This part is used for channel sensing purposes (including the reserved time-frequency resources for transmissions, demodulation reference signal (DMRS) pattern and antenna port, etc.) and can be read by all UEs while the remaining (second stage) scheduling and control information such as an 8-bits source identity (ID) and a 16-bits destination ID, NDI, RV and HARQ process ID is sent on the PSSCH to be decoded by the receiver UE.
Similar as for PROSE in LTE, NR sidelink transmissions have the following two modes of resource allocations:
For the in-coverage UE, a gNB can be configured to adopt Mode 1 or Mode 2. For the out-of-coverage UE, only Mode 2 can be adopted. As in LTE, scheduling over the sidelink in NR is done in different ways for Mode 1 and Mode 2. Mode 1 supports the following two kinds of grants:
In both dynamic grant and configured grant, a sidelink receiver UE cannot receive the DCI (since it is addressed to the transmitter UE), and therefore a receiver UE should perform blind decoding to identify the presence of PSCCH and find the resources for the PSSCH through the SCI. When a transmitter UE launches the PSCCH, CRC is also inserted in the SCI without any scrambling.
In the Mode 2 resource allocation, when traffic arrives at a transmitter UE, this transmitter UE should autonomously select resources for the PSCCH and the PSSCH. To further minimize the latency of the feedback HARQ ACK/NACK transmissions and subsequently retransmissions, a transmitter UE may also reserve resources for PSCCH/PSSCH for retransmissions. To further enhance the probability of successful TB decoding at one shot and thus suppress the probability to perform retransmissions, a transmitter UE may repeat the TB transmission along with the initial TB transmission. This mechanism is also known as blind retransmission. As a result, when traffic arrives at a transmitter UE, then this transmitter UE should select resources for the following transmissions:
Since each transmitter UE in sidelink transmissions should autonomously select resources for above transmissions, how to prevent different transmitter UEs from selecting the same resources turns out to be a critical issue in Mode 2. A particular resource selection procedure is therefore imposed to Mode 2 based on channel sensing. The channel sensing algorithm involves measuring RSRP on different subchannels and requires knowledge of the different UEs power levels of DMRS on the PSSCH or the DMRS on the PSCCH depending on the configuration. This information is known only after receiver SCI launched by (all) other UEs. The sensing and selection algorithm is rather complex.
There are device-to-device (D2D) discovery procedures for detection of services and applications offered by other UEs in close proximity. The discovery procedure has two modes, mode A based on open announcements (broadcasts) and mode B, which is request/response. The discovery mechanism is controlled by the application layer, e.g. the ProSe layer. In NR the discovery message is sent on the PSSCH. The discovery procedure can be used to detect UEs supporting certain services or applications before initiating the communication. Both dedicated discovery resource pool (i.e., only discovery message can be transmitted in the pool) and shared resource pool configuration (i.e., both discovery message and other data&control message can be transmitted in the pool) are supported in NR, whether dedicated discovery resource pool is configured is based on network implementation.
The adaptation rely layer within the UE-to-Network Relay UE can differentiate between signaling radio bearers (SRBs) and data radio bearers (DRBs) for a particular Remote UE. The adaption relay layer is also responsible for mapping PC5 traffic to one or more DRBs of the Uu. The definition of the adaptation relay layer is under the responsibility of RAN WG2.
The role of the UE-to-Network Relay UE is to relay the PDUs from the signaling radio bearer without any modifications.
NOTE: The current procedures shown here assume a single hop relay.
The Relay's AMF may perform authentication of the UE-to-Network Relay UE based on NAS message validation and if needed the AMF will check the subscription data.
If the UE-to-Network Relay UE is already in CM_CONNECTED state and is authorized to perform Relay service then step 5 is omitted.
NOTE: It is assumed that the Remote UE's PLMN is accessible by the UE-to-Network Relay's PLMN and that UE-to-Network Relay UE AMF supports all S-NSSAIs the Remote UE may want to connect to.
If Remote UE has not performed the initial registration to the network in step 0, the NAS message is initial registration message. Otherwise, the NAS message is service request message.
If the Remote UE performs initial registration via the UE-to-Network relay, the Remote UE's serving AMF may perform authentication of the Remote UE based on NAS message validation and if needed the Remote UE's AMF checks the subscription data.
For service request case, User Plane connection for PDU Sessions can also be activated.
L2 UE-to-Network Relay uses the RAN2 principle of the Rel-15 NR handover procedure as the baseline AS layer solution to guarantee service continuity, i.e., gNB hands over the Remote UE to a target cell or target Relay UE, including:
NOTE: The order of step 6/7/8 is not restricted. Following are further discussed in WI phase, including:
The methods and solutions described herein allowing the gNB, the remote UE, or the core network (CN) to be able to page the relay UE chosen as target relay UE for the sidelink relay path switch procedure. In order to do so, upon receiving the measurement report from the remote UE and if a relay UE in RRC_IDLE/INACTIVE has been selected as target relay UE by the gNB, at least one (or a combination) of the following solutions can be applied:
The embodiments are described in the context of NR, i.e., remote UE and relay UE are deployed in a same or different NR cell. The embodiments are also applicable to other relay scenarios including UE to network relay or UE to UE relay where the remote UE and the relay UE may be based on LTE sidelink or NR sidelink, the Uu connection between the relay UE and the base station may be LTE Uu or NR Uu.
The terms “direct connection” or “direct path” are used to stand for a connection between a UE and a gNB, while the terms “indirect connection” or “indirect path” are used to stand for a connection between a remote UE and gNB via a relay UE. In addition, the term “path switch” is used when the remote UE changes between a direct path (i.e., Uu connection) and an indirect path (i.e., relay connection via a SL relay UE). The other term such as “relay selection/reselection” is equally applicable here without losing any meaning.
In the following embodiments, the scenario considered is when the remote UE sends a measurement report to the gNB with a list of candidate relay UEs in which RRC status can be either RRC_CONNECTED, RRC_IDLE, or RRC_INACTIVE. The embodiments described herein consider the use case when a relay UE in RRC_IDLE or RRC_INACTIVE is selected by the gNB as the target relay UE for the path switch procedure. The remote UE when reporting the list of candidate relay UEs to the gNB, the remote UE also reports for each relay UE in the list also a respective ID that can be used by the gNB, CN, or remote UE to perform paging (or send some control plane signaling) to the relay UE.
In step 3, a NG Application Protocol (NG-AP) message with SAE-Temporary Mobile Subscriber Identity (S-TMSI) and a paging request is transmitted to the CN 108 or at least one entity of the CN 108. In the example in
In step 4, the CN 108 or entity of the CN 108 transmits a response message to the gNB 106 indicating whether the CN 108 accepted or rejected the paging request. If the CN 108 accepted the paging request, in step 5, the CN 108 or entity performs the paging procedure. In step 5, the CN 108 transmits a NG-AP paging message to the gNB 106 and in step 6, the paging message is forwarded by the gNB 106 to the target relay UE 104 to request or instruct the target relay UE to transit to an RRC_CONNECTED state for sidelink relay path switch purposes. As described with reference to at least
In step 7, RRC reconfiguration is performed by the relay UE transiting to the RRC_CONNECTED state for serving as a sidelink relay path switch for the remote UE 102.
In block 704, the method 700 includes selecting, by the network node, a target relay UE for the sidelink relay path switch from the list of candidate relay UEs.
In block 706, the method 700 includes transmitting, by the network node, a paging request to an entity of a core network (CN). The paging request includes a request or instructions for the entity of the CN to page or instruct the target relay UE to transit to an RRC_CONNECTED state for sidelink relay path switch purposes. In some examples, transmitting the paging request includes transmitting an NG-AP request message with a (Serving Temporary Mobile Subscriber Identity (S-TMSI) and the paging request. The NG-AP request message includes one of:
Upon receiving a measurement report from a remote UE with a list of candidate relay UE(s), if the gNB selects as target relay UE a relay UE that is in RRC_IDLE or RRC_INACTIVE, the gNB sends a message to at least one entity at the CN in order to indicate that the target relay UE chosen for the sidelink relay path switch needs to be paged to indicate to the relay UE that the target relay UE needs to transit to RRC_CONNECTED for sidelink relay path switch purposes.
When the gNB sends a message to at least one entity at the CN in order to indicate that the target relay UE chosen for the sidelink relay path switch needs to be paged so to indicate to the relay UE that it needs to transit to RRC_CONNECTED for sidelink relay path switch purposes, the gNB may include one (or a combination) of the following information:
In block 708, the method 700 includes receiving the paging request by the CN 108 or entity. In block 710, the method 700 includes transmitting the reply message to the gNB 106. In block 712, the method 700 includes performing the paging procedure by the CN 108 or entity in response to accepting the paging request.
Upon receiving the message or paging request from the gNB to page a certain target relay UE for sidelink relay path switch purposes, the CN (e.g., the entity at the CN that received this message) may reply to the gNB on whether the CN agreed to page the target relay UE or reject the gNB request. Whether the CN accepts or reject the gNB request, the CN may indicate this to the gNB. If the CN 108 or entity accepts the gNB request, the CN starts the CN-initiated paging procedure in order to page the target relay UE. When sending the paging to the target relay UE 104, the CN 106 may include a paging cause in the paging message in order to indicate to the relay UE 104 that this paging message is for sidelink relay path switch purposes. The CN may eventually send a message to the gNB 106 for informing the gNB 106 that the paging message has been sent and the gNB 106 may start a timer. If the timer expires and the relay UE has not transited to RRC_CONNECTED, the gNB 106 determines that the relay UE is not willing to accommodate the remote UE and the gNB may perform further actions.
In block 714, the method 700 includes receiving, by the gNB 106, a reply message from the CN 108 entity of the CN 108. The reply message indicates that the CN 108 or entity accepted the paging request to page the target relay EU 104, or the CN 108 rejects the paging request.
In block 716, the method 700 includes starting a timer for the target relay to transit to the RRC_CONNECTED state before expiration of the timer in response to the reply message indicating the CN accepted the paging request.
In block 718, the method 700 includes performing one or more of a set of actions in response to the entity of the CN rejecting the paging request. In some examples, the set of actions include:
Transmitting the paging request in block 706 corresponds to step 3 in
In block 1404, the method 1400 includes selecting, by the network node, a target relay UE for the sidelink relay path switch from the list of candidate relay UEs. In block 1406, the method 1400 includes transmitting, by the network node, a paging request to the target relay UE. The paging request includes a request or instructions for the target relay UE to transit to a RRC_CONNECTED state for sidelink relay path switch purposes. In some examples, the paging request includes a paging cause to inform the target relay UE that the paging request is for sidelink relay path switch purposes.
In block 1408, the method 1400 includes starting a timer by the gNB 106. The network node or gNB 106 performs one or more of a set of actions in response to the target relay UE not transiting to the RRC_CONNECTED state by expiration of the timer or the target relay UE failing to transit to the RRC_CONNECTED state without starting any timer.
In block 1410, the method 1400 includes receiving the page by a target relay UE 108. In block 1412, the method 1400 includes transiting to RRC_CONNECTED by the target relay UE 108 in response to accepting the page. In some circumstances, the target relay UE 108 may skip or ignore the page or paging request. In block 1414, the method 1400 includes transmitting, by the target relay UE 108, a notification to the gNB 106 that the target relay UE 108 does not accept the page to transit to the RRC_CONNECTED state.
In block 1416, the method 1400 includes receiving, by the network node or gNB 106, a notification from the target relay UE 108 that the target relay UE 108 cannot serve as a relay UE or does not want to serve as the relay UE. In some examples, the method 1400 also includes determining by the network node that the target relay UE ignored the paging request via using a timer or another mechanism and performing one or more of a set of actions in response to receiving the notification or determining that the target relay UE ignored the paging request. In some examples, the one or more actions comprises: aborting path switch procedure and release the remote UE to RRC_IDLE or RRC_INACTIVE; selecting a new target relay UE from the list of candidate relay UEs received from the remote UE, whatever the RRC state of the relay UE in the list is; selecting a new target relay UE from the list of candidate relay UEs but only among those relay UEs which are in RRC_CONNECTED state; and sending a message to the remote UE for informing that the target relay UE is not available and that a new list of candidate relay UEs needs to be produced by the remote UE and then send to the network node.
In some examples, upon receiving a measurement report from a remote UE with a list of candidate relay UE(s), if the gNB selects as target relay UE that is in RRC_IDLE or RRC_INACTIVE, the gNB decides to page the target relay UE to indicate that the target relay UE needs to transit to RRC_CONNECTED. When paging the target relay UE, the gNB may also include a paging cause to inform the target relay UE that this paging is for sidelink relay path switch purposes.
When the gNB pages the target relay UE to indicate that the target relay UE needs to transit to RRC_CONNECTED, the gNB may also start a timer and if the relay UE does not transit to RRC_CONNECTED by the expiring of this timer, the gNB may perform at least one (or a combination) of the following actions: abort the whole path switch procedure and release the remote UE to RRC_IDLE or RRC_INACTIVE; select a new target relay UE from the list of candidate relay UEs received by the remote UE, whatever the RRC state of the relay UE in the list is; select a new target relay UE from the list of candidate relay UEs among those relay UEs which are in RRC_CONNECTED state; sends a message to the remote UE for informing that the target relay UE is not available and that a new list of candidate relay UEs needs to be produced by the remote UE (and then send to the gNB). The gNB may also perform these actions when the procedure for the relay UE to transit to RRC_CONNECTED fails (e.g, random access fails or RRC resume fails) and without necessarily starting any timer.
In block 1504, the method 1500 includes selecting, by the network node, a target relay UE for the sidelink relay path switch from the list of candidate relay UEs.
In block 1506, the method 1500 includes transmitting, by the network node, a request message to the remote UE. The request message includes a request or instructions for the remote UE to establish a connection with the target relay UE and page or request the target relay UE to transit to an RRC_CONNECTED state for sidelink relay path switch purposes.
In block 1510, the method 1500 includes receiving the request message, by the remote UE 102, from a network node or gNB 106. The request message includes instructions for the remote UE to establish a connection with a target relay UE and instruct the target relay UE to transit to an RRC_CONNECTED state.
In block 1512, the method 1500 includes transmitting, by the remote UE 102, a page or instructions to the target relay UE 108 to transit to the RRC_CONNECTED state.
In block 1514, the method 1500 includes reporting to the network node or gNB 106 if the target relay UE accepted or rejected the page to transit to the RRC_CONNECTED state.
In block 1516, the method 1500 includes triggering, by the remote UE 102, a discovery procedure and/or a RRC reestablishment procedure and/or a relay re-selection procedure in response to the target relay UE 108 rejecting the page and not transiting to the RRC_CONNECTED state.
In block 1518, the method 1500 includes receiving, by the network node or gNB 106, a report from the remote UE 102 indicating whether the target relay UE accepted or rejected the page or request to transit to the RRC_CONNECTED state.
In block 1520, the network node or gNB 106 performs one or more of a set of actions in response to the target relay UE rejecting the page or request to transit to the RRC_CONNECTED state. The set of actions includes aborting path switch procedure and release the remote UE to RRC_IDLE or RRC_INACTIVE; selecting a new target relay UE from the list of candidate relay UEs received from the remote UE, whatever the RRC state of the relay UE in the list is; selecting a new target relay UE from the list of candidate relay UEs but only among those relay UEs which are in RRC_CONNECTED state; and sending a message to the remote UE for informing that the target relay UE is not available and that a new list of candidate relay UEs needs to be produced by the remote UE and then send to the network node.
In some examples, upon receiving a measurement report from a remote UE with a list of candidate relay UE(s), if the gNB selects as target relay UE that is in RRC_IDLE or RRC_INACTIVE, the gNB sends an indication, e.g., a the path switch command or an RRC reconfiguration message to the remote UE with an indication that the remote UE should establish a PC5 connection with the relay UE (if not available yet) and then the remote UE should indicate to the target relay UE that it should transit to RRC_CONNECTED.
In some examples, upon receiving the request from the gNB to establish a PC5 connection with the relay UE (if not available yet) and then indicate to the target relay UE that it should transit to RRC_CONNECTED, the remote UE reports back to the gNB if the relay UE has accepted or rejected to transit to RRC_CONNECTED. Then, when receiving this indication from the remote UE, the gNB can perform at least one (or a combination) of the following actions:
In accordance with any of the previously described embodiments, if the target relay UE decides to skip or ignore the paging (i.e., does not transit to RRC_CONNECTED because does not want to serve as a relay UE), the target relay UE may inform the gNB about this during the transit to RRC_CONNECTED (e.g., in the random access, RRC setup, or RRC resume procedure). Alternatively, the relay UE does not inform the gNB but the gNB may determine that the target relay UE skipped or ignored the paging via the use of a timer or some other mechanism. Thus, in case the target relay UE skips or ignores the paging or does not want to act as a relay UE, the gNB can perform at least one (or a combination) of the actions previously described.
In some examples, the relay UE 108 that the remote UE 102 should use is decided by the gNB 106 and communicated to the remote UE 102 via dedicated RRC signaling of system information. As another alternative, which option(s) the UE should use is decided by TX/RX UE or is pre-configured (hard-coded in the spec).
In at least some of the embodiments and examples described herein, the signaling alternatives described will include at least one of the following
In a further embodiment, a remote UE sends a measurement report to the gNB including, together with measurements, also a list of potential relay UE candidates selected based on certain criteria that are part of the measurement configuration. This list of potential relay UE candidates can include relay UE(s) in any RRC state, such as RRC_IDLE, RRC_INACTIVE, or RRC_CONNECTED mode. Since the gNB may use the measurements and the list of candidate relay UEs to trigger a path switch procedure, when sending the list of relay UE candidates, the remote UE may also include for each relay UE at least one of (or a combination of) the following information:
The relay UE ID used for communication on the PC5 interface (e.g., the L2 ID)
The relay UE ID used for communication on the Uu interface (e.g., RNTI or any other ID assigned by the gNB).
A mapping between the ID used by the relay UE over PC5 (e.g., the L2 ID) and the ID used by the relay UE over Uu (e.g., RNTI or any other ID assigned by the gNB).
In a further embodiment, once receiving the measurement report from the remote UE with the list of candidate relay UE, if the gNB has selected a relay UE in RRC_IDLE state as target relay UE for a path switch procedure, the gNB may perform one of (or a combination of) the following actions to instruct the relay UE to transition to RRC_CONNECTED:
The gNB initiates a signaling to the CN (e.g., by contacting the AMF), indicating the reported relay UE ID(s) in the measurement report, to either acquire the UE-TMSI value to page the relay UE or trigger the paging directly by the CN.
If the UE-TMSI is already part of the measurement report received from the remote UE, the gNB may directly page the relay UE to indicate that needs to transition to RRC_CONNECTED. To do so, it may indicate as paging cause that the paging procedure is for relay purposed or for incoming data on the remote UE.
On the other side, when the CN receives the indication from the gNB requesting to page the UE, the CN may perform one of (or a combination of) the following actions:
Provide the gNB with the UE-TMSI value or a similar UE ID for the gNB to perform the corresponding mapping/association with the reported relay UE ID and to allow the gNB to page the relay UE (to indicate the relay UE to transition to RRC_CONNECTED). The result of the mapping/association can also be a third relay UE ID which is different from the reported relay UE ID and the UE-TMSI value. With this it is assumed that the CN can achieve a mapping association between the PC5 and Uu IDs of the relay UEs. For instance, the AMF may query the vehicle-to-X (V2X) layer or the ProSe layer about what ID a relay UE is using over PC5, and vice versa. Also, certain embodiments perform this procedure every time that a relay UE is selected as target relay UE for a path switch.
The CN, if it already has a map association between all the relay UE IDs over PC5 and Uu, it sends the whole map to the gNB. The gNB will then use this to page the relay UE to indicate to transition to RRC_CONNECTED. With this, it is assumed that the CN maintains this mapping over time, for example, every time and a new relay UE is selected or used. Also, in certain embodiments, the gNB requests the mapping once and thereafter need only request a new mapping if a new relay UE (that is not in the current mapping) is selected as candidate relay UE for a path switch.
In a further embodiment, a relay UE in a CONNECTED state transmits the relay UE ID used for communication on the PC5 interface to the gNB. The gNB then performs the mapping/association between the reported relay UE ID and the assigned temporary identifier, e.g., I-RNTI or C-RNTI. The result of the mapping/association can also be a third relay UE ID that is different from the reported UE ID and the RNTI values. This is signaled to the relay UE. Certain embodiments use this only for path switch purposes.
In a further embodiment, the remote UE, upon sending a measurement report to the gNB as described in the previous embodiments, receives in response a path switch command from the gNB with a target relay UE ID in RRC_IDLE or RRC_INACTIVE state. In this case, to instruct the relay UE to perform the RRC establishment/resume/random access procedure to transition to RRC_CONNECTED, the remote UE can perform one of (or a combination of) the following actions:
The remote UE establishes a PC5 connection with the relay UE (if not yet established) and signals an indication to the target relay UE to transition to CONNECTED for sidelink relay purpose. The indication may be implicit or explicit. In case of an implicit indication, this means that a candidate relay UE should interpret any message/signaling received from the remote UE as an indication to transition to CONNECTED state, even if the message/signaling is empty.
The remote UE establishes a PC5 connection with the relay UE (if not yet established) and send a signalling over PC5 to ask the relay UE to provide one or multiple IDs that the relay UE uses for Uu operations. Once that the relay UE replies with the IDs used for Uu operations, the remote UE may send another signalling to the gNB in order to inform what the correct IDs that the network should use in order to trigger a RRC establishment/resume procedure to the correct relay UE (i.e., selected by the network for the path switch procedure).
In a further embodiment, the PC5 configuration (i.e., PC5 radio link control (RLC)/medium access control (MAC)/physical layer (PHY) setup) used in the fourth embodiment to explicitly or implicitly signal to the target relay UE can either be pre-defined/pre-configured/default configuration in the specification or embedded in the sim card (Universal Subscriber Identity Module (USIM)/Universal Integrated Circuit Card (UICC)).
In a further embodiment, the PC5 configuration used in the fourth embodiment can also include a pre-defined/pre-configured/default adaptation layer configuration and adaptation layer header.
In a further embodiment, the remote UE of the fourth embodiment, on receiving the path switch command from the gNB with a target relay UE ID in RRC_IDLE or RRC_INACTIVE state can trigger a broadcast or groupcast signal including at least the relay UE ID used for communication on the PC5 interface and/or a third relay UE ID to trigger an RRC establishment/resume/random access procedure in the target relay UE.
In addition, a network node such as gNB or a controlling UE includes a configuration for the remote UE in the RRC message sent to the relay UE (as separate information elements (IEs) or within a container), the relay UE then forwards the configuration to the remote UE using PC5-RRC. In case the container is used, the relay UE can simply put the container in its PC5-RRC without decoding it.
As discussed herein, operations of communication device UE may be performed by processing circuitry 1603 and/or transceiver circuitry 1601. For example, processing circuitry 1603 may control transceiver circuitry 1601 to transmit communications through transceiver circuitry 1601 over a radio interface to a radio access network node (also referred to as a base station) and/or to receive communications through transceiver circuitry 1601 from a RAN node over a radio interface. Moreover, modules may be stored in memory circuitry 1605, and these modules may provide instructions so that when instructions of a module are executed by processing circuitry 1603, processing circuitry 1603 performs respective operations. According to some embodiments, a communication device UE 1600 and/or an element(s)/function(s) thereof may be embodied as a virtual node/nodes and/or a virtual machine/machines.
As discussed herein, operations of the RAN node may be performed by processing circuitry 1703, network interface 1707, and/or transceiver 1701. For example, processing circuitry 1703 may control transceiver 1701 to transmit downlink communications through transceiver 401 over a radio interface to one or more mobile terminals UEs and/or to receive uplink communications through transceiver 1701 from one or more mobile terminals UEs over a radio interface. Similarly, processing circuitry 1703 may control network interface 407 to transmit communications through network interface 1707 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 1705, and these modules may provide instructions so that when instructions of a module are executed by processing circuitry 1703, processing circuitry 1703 performs respective operations. According to some embodiments, RAN node 1700 and/or an element(s)/function(s) thereof may be embodied as a virtual node/nodes and/or a virtual machine/machines.
According to some other embodiments, a network node may be implemented as a core network CN node without a transceiver. In such embodiments, transmission to a wireless communication device UE may be initiated by the network node so that transmission to the wireless communication device UE is provided through a network node including a transceiver (e.g., through a base station or RAN node). According to embodiments where the network node is a RAN node including a transceiver, initiating transmission may include transmitting through the transceiver.
As discussed herein, operations of the CN node may be performed by processing circuitry 1803 and/or network interface circuitry 1807. For example, processing circuitry 1803 may control network interface circuitry 1807 to transmit communications through network interface circuitry 1807 to one or more other network nodes and/or to receive communications through network interface circuitry from one or more other network nodes. Moreover, modules may be stored in memory 505, and these modules may provide instructions so that when instructions of a module are executed by processing circuitry 503, processing circuitry 503 performs respective operations. According to some embodiments, CN node 500 and/or an element(s)/function(s) thereof may be embodied as a virtual node/nodes and/or a virtual machine/machines.
1. A method performed by a network node (or gNB) for on demand paging for executing a sidelink relay path switch, the method comprising:
2. The method of embodiment 1, wherein the paging request comprises at least one of: an identifications (ID) of the target relay UE;
3. The method of claim 2, wherein ID of the target relay UE comprises a UE-TMSI, RNTI, or any other ID useful to identify the relay UE at the CN; and wherein the ID of the remote UE comprises the UE-TMSI, RNTI, or any other ID useful to identify the remote UE at the CN).
4. The method of any of the previous embodiments, further comprising:
5. The method of embodiment 4, further comprising starting a timer for the target relay to transit to the RRC_CONNECTED state before expiration of the timer in response to the reply message indicating the CN accepted the paging request.
6. The method of any of embodiments 4 or 5, wherein the set of actions comprises:
7. The method of any of the previous embodiments, wherein transmitting the paging request comprises transmitting an NG-AP request message with a (Serving Temporary Mobile Subscriber Identity (S-TMSI) and the paging request.
8. The method of embodiment 7, wherein the NG-AP request message comprises one of:
9. A method performed by a network node (or gNB) for on demand paging for executing a sidelink relay path switch, the method comprising:
10. The method of embodiment 9, wherein the paging request comprises a paging cause to inform the target relay UE that the paging request is for sidelink relay path switch purposes.
11. The method of embodiment 9, further comprising starting a timer, wherein the network node performs one or more of a set of actions in response to the target relay UE not transiting to the RRC_CONNECTED state by expiration of the timer or the target relay UE failing to transit to the RRC_CONNECTED state without starting any timer.
12. The method of embodiment 9, further comprising:
13. The method of any of embodiments 11 or 12, wherein the one or more actions comprises: wherein the set of actions comprises:
selecting a new target relay UE from the list of candidate relay UEs but only among those relay UEs which are in RRC_CONNECTED state; and
14. A method performed by a network node (or gNB) for on demand paging for executing a sidelink relay path switch, the method comprising:
15. The method of embodiment 13, further comprising receiving a report from the remote UE indicating whether the target relay UE accepted or rejected the page or request to transit to the RRC_CONNECTED state.
16. The method of embodiment 14, wherein the network node performs one or more of a set of actions in response to the target relay UE rejecting the page or request to transit to the RRC_CONNECTED state.
17. The method of embodiment 15, wherein the one or more actions comprises: wherein the set of actions comprises:
18. A method performed by a network node (CN (AMF)) for on demand paging for executing a sidelink relay path switch, the method comprising:
19. The method of embodiment 18, wherein performing the paging procedure comprises transmitting a paging message to the target relay UE, wherein the paging message comprises a paging cause to indicate to the target relay UE that the paging message is for sidelink relay path switch purposes.
20. The method of any of the previous embodiments, further comprising transmitting a message to the other network node that the paging message has been transmitted to the target relay UE so the other network node may start a timer so that until the timer expires the target relay UE did not transit to an RRC_CONNECTED state, the other network node understands that the target relay is not willing to accommodate a remote UE and the other network node may perform further actions.
21. The method of embodiment 18, wherein the paging request comprises at least one of:
22. A method performed by a user equipment (a target relay UE) for on demand paging for executing a sidelink relay path switch, the method comprising:
23. A method performed by a user equipment (a remote UE) for on demand paging for executing a sidelink relay path switch, the method comprising:
24. The method of embodiment 23, further comprising triggering a discovery procedure and/or a RRC reestablishment procedure and/or a relay re-selection procedure in response to the target UE rejecting the page and not transiting to the RRC_CONNECTED state.
Group F embodiments
25. The method of any of Group A-E embodiments, wherein signaling between network nodes (gNBs) comprises at least one of X2/Xn signaling, F1 signaling, and/or inter-node RRC messages.
26. The method of any of Group A-E embodiments, wherein signaling between any of the UEs and the network node (gNB) comprises at least one of RRC signaling, MAC CE, L1 signaling on channels such as PRACH, PUCCH, PDCCH, and/or control PDU of a protocol layer such as SDAP, PDCP, RLC or an adaptation layer which is introduced for responsible of duplication function.
27. The method of any of Group A-E embodiments, wherein signaling between UEs (remoter US and target relay UE) comprises RRC signaling (e.g., PC5-RRC), PC5-S signaling, Discovery signaling, MAC CE, L1 signaling on channels such as PSSCH, PSCCH, or PSFCH, and/or Control PDU of a protocol layer such as SDAP, PDCP, RLC or an adaptation layer which is introduced for responsible of duplication function.
28. The method of any of Group A-E embodiments, wherein signaling between the gNB and the CN and between CN entities comprises NG messages.
Group G Embodiments
29. A user equipment for on demand paging for executing a sidelink relay path switch, the user equipment comprising:
30. A network node for on demand paging for executing a sidelink relay path switch, the network node comprising:
A1. A method performed by a remote user equipment (UE), the method comprising:
A2. The method of embodiment A1, wherein the list of the relay UE candidates is sent in a measurement report.
A3. The method of any of embodiments A1-A2, wherein the list of relay UE candidates comprises at least one relay UE candidate in an idle state.
A4. The method of any of embodiments A1-A3, wherein the list of relay UE candidates comprises at least one relay UE candidate in an inactive state.
A5. The method of any of embodiments A1-A4, wherein the list of relay UE candidates comprises at least one relay UE candidate in a connected state.
A6. The method of any of embodiments A1-A5, wherein the list of the relay UE candidates comprises, for each relay UE candidate, a first identifier configured to identify the relay UE candidate with respect to the sidelink communication.
A7. The method of embodiment A6, wherein the first identifier comprises a layer 2 identifier (L2 ID).
A8. The method of any of embodiments A1-A7, wherein the sidelink communication comprises communication via a PC5 interface.
A9. The method of any of embodiments A1-A8, wherein the list of the relay UE candidates comprises, for each relay UE candidate, a second identifier configured to identify the relay UE candidate with respect to communication with a radio access network or core network.
A10. The method of embodiment A9, wherein the second identifier comprises a temporary mobile subscriber identity (TMSI).
A11. The method of embodiment A9, wherein the second identifier comprises a radio network temporary identifier (RNTI).
A12. The method of any of embodiments A1-A11, wherein the communication with the radio access network or core network comprises communication via a Uu interface.
A13. The method of any of embodiments Al-A12, wherein the list of the relay UE candidates comprises a mapping between a first identifier and a second identifier, the first identifier configured to identify the relay UE candidate with respect to the sidelink communication and the second identifier configured to identify the relay UE candidate with respect to communication with a radio access network or core network.
A14. The method of any of embodiments A1-A13, further comprising:
A15. The method of any of the previous embodiments, further comprising:
B1. A method performed by a radio access network node (e.g., a base station, such as a gNB), the method comprising:
B2. The method of embodiment B1, wherein the first identifier comprises a layer 2 identifier (L2 ID).
B3. The method of embodiment B1 or B2, wherein the second identifier comprises a temporary mobile subscriber identity (TMSI).
B4. The method of embodiment B1 or B2, wherein the second identifier comprises a radio network temporary identifier (RNTI).
B5. The method of any of embodiments B1-B4, further comprising:
B6. The method of embodiment B5, wherein the page is sent from the radio access network node (e.g., base station) to the relay UE.
B7. The method of embodiment B5, wherein initiating the sending of the page comprises requesting the core network (CN) to page the relay UE.
B8. The method of any of embodiments B1-B7, further comprising:
B9. The method of any of embodiments B1-B8, further comprising:
B10. The method of embodiment B9, wherein the relay UE indicates that the remote UE has data to transmit by initiating an access procedure, a procedure for establishing a connection, or a procedure for resuming the connection.
B11. The method of any of embodiments B1-B10, further comprising:
B12. The method of any of embodiments B1-B11, further comprising obtaining the first identifier from the relay UE.
B13. The method of any of embodiments B1-B12, wherein determining the mapping comprises:
B14. A method performed by a core network, the method comprising:
B15. The method of embodiment B14, wherein the first identifier comprises a layer 2 identifier (L2 ID).
B16. The method of any of embodiments B14-B15, wherein the second identifier comprises a temporary mobile subscriber identity (TMSI) or a radio network temporary identifier (RNTI).
B17. The method of any of embodiments B1-B16, wherein the sidelink communication comprises communication via a PC5 interface and wherein the communication with the radio access network or the core network comprises communication via a Uu interface.
B18. The method of any of the previous embodiments, further comprising:
C1. A user equipment, comprising:
C2. A network node, the network node comprising:
C3. A user equipment (UE), the UE comprising:
C4. A host configured to operate in a communication system to provide an over-the-top (OTT) service, the host comprising:
C5. The host of the previous embodiment, wherein the cellular network further includes a network node configured to communicate with the UE to transmit the user data to the UE from the host.
C6. The host of the previous 2 embodiments, wherein:
C7. A method implemented by a host operating in a communication system that further includes a network node and a user equipment (UE), the method comprising:
C8. The method of the previous embodiment, further comprising:
C9. The method of the previous embodiment, further comprising:
C10. A host configured to operate in a communication system to provide an over-the-top (OTT) service, the host comprising:
C11. The host of the previous embodiment, wherein the cellular network further includes a network node configured to communicate with the UE to transmit the user data from the UE to the host.
C12. The host of the previous 2 embodiments, wherein:
C13. A method implemented by a host configured to operate in a communication system that further includes a network node and a user equipment (UE), the method comprising:
C14. The method of the previous embodiment, further comprising:
C15. The method of the previous embodiment, further comprising:
C16. A host configured to operate in a communication system to provide an over-the-top (OTT) service, the host comprising:
C17. The host of the previous embodiment, wherein:
C18. A method implemented in a host configured to operate in a communication system that further includes a network node and a user equipment (UE), the method comprising:
C19. The method of the previous embodiment, further comprising, at the network node, transmitting the user data provided by the host for the UE.
C20. The method of any of the previous 2 embodiments, wherein the user data is provided at the host by executing a host application that interacts with a client application executing on the UE, the client application being associated with the host application.
C21. A communication system configured to provide an over-the-top service, the communication system comprising:
C22. The communication system of the previous embodiment, further comprising:
C23. A host configured to operate in a communication system to provide an over-the-top (OTT) service, the host comprising:
C24. The host of the previous 2 embodiments, wherein:
C25. The host of the any of the previous 2 embodiments, wherein the initiating receipt of the user data comprises requesting the user data.
C26. A method implemented by a host configured to operate in a communication system that further includes a network node and a user equipment (UE), the method comprising:
C27. The method of the previous embodiment, further comprising at the network node, transmitting the received user data to the host.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/078814 | 10/17/2022 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63270493 | Oct 2021 | US | |
| 63257372 | Oct 2021 | US |
