HANDLING OF LINK DEGRADATION IN WIRELESS BACKHAUL LINKS
FIELD
[0001] The present disclosure relates to wireless communication networks, and in particular to wireless communication networks that utilize wireless backhaul connections.
BACKGROUND
[0002] A 3 GPP Release 19 (Rel-19) Study Item Description (SID) for the Rel-19 Study on additional topological enhancements for NR in RP -234041 has been approved for the study of Wireless Access and Backhaul (WAB), which refers to a mobile/wireless gNodeB (gNB) and 5G Femto architectures.
[0003] The justification of the WAB part of the SI is that the legacy building blocks for 5G radio access network (RAN) topologies should be enhanced to provide a broader range of use cases, such as:
5G access for user equipments (UEs) onboard aircrafts, cruise ships, helicopters, and vehicles in remote areas with limited sky visibility via an onboard gNB.
Backhauling of NG and Xn via terrestrial networks (TN) and non-terrestrial networks (NTN), including support of NTN-TN handover for backhaul.
Support for onboard/on-site multi-access edge computing (MEC) and local services.
Support for backhauling without RAN-sharing or roaming agreements between access public land mobile networks (PLMNs) and backhaul PLMNs.
Backhauling for local gNB deployed in public safety or disaster recovery scenarios.
[0004] It is assumed that WAB is aligned with vehicle-mounted relay (VMR) use cases and with the SA2-endorsed SID on architectural enhancements for Rel-19 VMR. It is expected that single-hop backhauling is sufficient for WAB and that there is no impact to UEs at this late stage of 5G deployment.
[0005] The objectives from the SID related to the WAB study are as follows: Study the support of WAB.
Study the architecture and protocol stack of supporting a gNB with mobile termination (MT) function providing packet data unit (PDU) session backhaul. Study impact of WAB mobility within an existing RAN (e.g., inter-gNB neighbour relations).
Identify necessary inter-gNB- and gNB-to- core network (CN) signalling to address the support of WAB.
Study signalling enhancements on resource multiplexing for WAB.
[0006] The WAB study does not preclude any backhaul scenario (e.g., NTN or TN).
[0007] A potential WAB architecture is shown in Figure 1. As shown in Figure 1, a WAB node 110 includes a WAB-gNB and a WAB-MT. The WAB-gNB part of the WAB node serves UEs, while the WAB node uses its WAB-MT part to connect with the rest of the mobile network, i.e., to connect to the WAB-MT’ s serving gNB (the BH-gNB 120 in Figure 1). In this architecture, the PDU sessions established between the WAB-MT and the BH-UPF are used to carry the next generation application protocol (NGAP) and XnAP connections of the WAB-gNB.
[0008] The 5G Core Network (5GC) serving the WAB-gNB with its connected UEs may be the same as or different from the 5G Core Network (5GC) serving the WAB- MT.
[0009] NG interface
[0010] The next generation (NG) control plane interface (NG-C) is defined between the NG-RAN node and the access and mobility function (AMF). The control plane protocol stack of the NG interface is shown in Figure 2. The transport network layer is built on internet protocol (IP) transport. For the reliable transport of signalling messages, SCTP is added on top of IP. The application layer signalling protocol is referred to as NGAP (NG Application Protocol). The stream control transport protocol (SCTP) layer provides guaranteed delivery of application layer messages. In the transport, IP layer point-to-point transmission is used to deliver the signalling PDUs.
[0011] NG-C provides functions including NG interface management, UE context management, UE mobility management, Transport of NAS messages, Paging, PDU Session Management, Configuration Transfer, and Warning Message Transmission.
[0012] NG User Plane
[0013] The NG user plane (NG-U) interface is defined between a NG-RAN node and a user plane function (UPF). The NG-U interface provides non guaranteed delivery of PDU Session/MBS session user plane PDUs between the NG-RAN node and the UPF. The protocol stack for NG-U is shown in Figure 3. [0014] Management of PDU sessions in 5G
[0015] PDU sessions are established in 5G between a UE and a data network to provide connectivity once the UE has been authenticated and established in a network.
[0016] The 5GC supports a PDU Connectivity Service i.e. a service that provides exchange of PDUs between a UE and a data network identified by a data network name (DNN). The PDU Connectivity Service is supported via PDU Sessions that are established upon request from the UE.
[0017] Each PDU Session supports a single PDU Session type i.e. supports the exchange of a single type of PDU requested by the UE at the establishment of the PDU Session. The following PDU Session types are defined: IPv4, IPv6, IPv4v6, Ethernet, Unstructured.
[0018] PDU Sessions are established (upon UE request), modified (upon UE and 5GC request) and released (upon UE and 5GC request) using non-access stratum (NAS) session management (SM) signalling exchanged over N1 between the UE and the SMF. Upon request from an Application Server, the 5GC is able to trigger a specific application in the UE. When receiving that trigger message, the UE shall pass it to the identified application in the UE. The identified application in the UE may establish a PDU Session to a specific DNN.
[0019] In a PDU Session Establishment Request message sent to the network, the UE shall provide a PDU Session ID. The PDU Session ID is unique per UE and is the identifier used to uniquely identify one of a UE's PDU Sessions. The PDU Session ID shall be stored in the unified data management (UDM) to support handover between 3 GPP and non-3GPP access when different PLMNs are used for the two accesses. The UE also provides: (a) PDU Session Type; (b) single network slice selection assistance information (S- NSSAI) of the home PLMN (HPLMN) that matches the application (that is triggering the PDU Session Request) within the network slice selection policy (NSSP) in the UE route selection policy (URSP) rules or within the UE Local Configuration; (c) S-NSSAI of the Serving PLMN from the Allowed NS SAI, corresponding to the S-NSSAI of the HPLMN (d) DNN; and (e) Service and Session Continuity (SSC) mode.
[0020] A UE may establish multiple PDU Sessions, to the same data network or to different data networks, via 3 GPP and via and Non-3GPP access networks at the same time. A UE may establish multiple PDU Sessions to the same Data Network and served by different UPF terminating N6. A UE with multiple established PDU Sessions may be served by different SMF.
[0021] 5G user plane and QoS framework [0022] The 5G user plane (UP) is shown in Figure 4. The UP failure handling procedure is as follows. Upon receiving an Error Indication from the 5G access network (i.e., the NG-RAN), the UPF shall identify the session and send an Error Indication Report to SMF. The Error Indication Report includes Remote Fully Qualified Tunnel Endpoint Identifier (F-TEID). For a GTP-U Error Indication received from a 5G-AN, the SMF shall modify the Packet Forwarding Control Protocol (PF CP) session to instruct the UPF to buffer downlink packets. If the user plane connection of the PDU session is seen as activated by the SMF, the SMF shall initiate an Namf_Communication_NlN2MessageTransfer service operation to request the 5G-AN to release the PDU session's resources.
SUMMARY
[0023] Some embodiments provide a method performed by a wireless base station in a wireless communication network. The wireless base station has a wireless backhaul connection to a backhaul base station. The method includes detecting link degradation in a wireless backhaul link between the wireless base station and the backhaul base station, and transmitting an indication of the detected link degradation to a network node in the wireless communication network.
[0024] The network node may include a core network node in a core network of the wireless communication network or a radio access node in an access network of the wireless communication network.
[0025] In some embodiments, the indication of link degradation is transmitted in a packet data unit, PDU, session related next generation application protocol (NGAP) message.
[0026] The NGAP message may include a NGAP PDU SESSION RESOURCE NOTIFY message, a NGAP UL PDU SESSION INFORMATION message, a NGAP UE context management message or a NGAP interface management message.
[0027] The indication may relate to a specific protocol data unit (PDU) session of a user equipment (UE) served by the wireless base station, a specific PDU session of a WAB- MT served by the backhaul base station, and/or to a plurality of PDU sessions served by the wireless base station. The indication may include a PDU session identifier corresponding to the specific PDU session or a list of PDU session identifiers corresponding to the plurality of PDU sessions.
[0028] In some embodiments, the indication relates to a plurality of UEs served by the wireless base station, and the indication comprises a list of UE identifiers corresponding to the plurality of UEs. [0029] In some embodiments, the indication is sent by user plane messaging or control plane messaging.
[0030] The indication may include information about whether an access link between the wireless base station and a user equipment, or the wireless backhaul link, or both, are experiencing degradation.
[0031] In some embodiments, the indication indicates whether the degradation is for uplink communications on the access link, downlink communications on the access link or both uplink and downlink communications on the access link.
[0032] The indication may include information about a cause of the degradation and/or a condition of the wireless backhaul link.
[0033] The indication may include information about a PDU session or UE affected by the link degradation, and/or a quality of service (QoS) requirement of the PDU session affected by the link degradation. The indication may include one or more UE identifiers, one or more PDU session identifiers, and/or a score of the link degradation.
[0034] The wireless base station may include a wireless access and backhaul gNodeB (WAB-gNB) and a WAB mobile termination (WAB-MT), wherein detecting link degradation in the wireless backhaul link between the wireless base station and the backhaul base station is performed by the WAB-MT.
[0035] In some embodiments, the WAB-MT notifies the WAB-gNB of the link degradation in the wireless backhaul link between the wireless base station and the backhaul base station, and wherein the WAB-gNB initiates the transmitting of the indication of link degradation to the network node.
[0036] In some embodiments, the WAB-gNB initiates the transmitting of the indication of link degradation to the network node via the WAB-MT, and wherein the WAB- MT transmits the indication of link degradation to the network node via radio resource control (RRC) signalling.
[0037] In some embodiments, the WAB-gNB initiates the transmitting of the indication of link degradation to the network node via XnAP or NGAP signalling.
[0038] In some embodiments, the WAB-MT applies active queue management to reduce an amount of traffic over a wireless backhaul in response to detecting link degradation in the wireless backhaul link between the wireless base station and the backhaul base station.
[0039] The network node may include a backhaul gNodeB, BH-gNB, that serves the WAB-MT. [0040] The network node may include a network function of a backhaul core network (BH-CN) that serves the WAB-MT.
[0041] The network node may include a network function of a UE core network (UE-CN) that serves a UE that is connected to the WAB-gNB.
[0042] Some further embodiments provide a method performed by a backhaul base station in a wireless communication network, wherein the backhaul base station has a wireless backhaul connection to a wireless base station. The method includes detecting link degradation in a wireless backhaul link between the wireless base station and the backhaul base station, and transmitting an indication of the detected link degradation to a network node in the wireless communication network.
[0043] Transmitting the indication of the detected link degradation may include transmitting the indication of the detected link degradation to the wireless base station.
[0044] The network node may include a core network node in a core network of the wireless communication network or a radio access node of an access network of the wireless communication network.
[0045] The indication may relate to a specific PDU session of a wireless access and backhaul mobile termination, WAB-MT, or a specific PDU session of a UE served by the wireless base station and/or to a plurality of PDU sessions served by the wireless base station, and the indication may include a PDU session identifier or a list of PDU session identifiers corresponding to the plurality of PDU sessions.
[0046] The indication may relate to a plurality of UEs served by the wireless base station, and the indication may include a list of UE identifiers corresponding to the plurality of UEs. The UE may be a WAB-MT served by the backhaul base station.
[0047] In some embodiments, the method indication is sent by user plane messaging or control plane messaging.
[0048] The indication may include information about whether an access link between the wireless base station and a user equipment, or the wireless backhaul link, or both, are experiencing degradation.
[0049] The indication may include information about a cause of the degradation and/or a condition of the wireless backhaul link.
[0050] The indication may include information about a PDU session or UE affected by the link degradation, and/or a QoS requirement of the PDU session affected by the link degradation. The indication may include one or more UE identifiers, one or more PDU session identifiers, and/or a score of the link degradation. [0051] The indication may include a pointer to a pre-configured degradation cause, degradation event or degradation level.
[0052] The method may further include sending a further indication of the link degradation to a network node in a core network serving the wireless base station or the UE. The further indication may request throttling of traffic carried by the wireless backhaul link.
[0053] In some embodiments, the further indication requests adjustment of a data rate, a priority or scheduling of bearers carried by the wireless backhaul link.
[0054] The method may further include transmitting the indication of the detected link degradation to the wireless base station.
[0055] The wireless base station may include a WAB-gNB and a WAB-MT, and transmitting the indication of the detected link degradation to the wireless base station may include transmitting the indication of the detected link degradation to the WAB-gNB and/or the WAB-MT.
[0056] Some further embodiments provide a method performed by a wireless base station in a wireless communication network, wherein the wireless base station has a wireless backhaul connection to a backhaul base station. The method includes detecting link degradation in a wireless backhaul link between the wireless base station and the backhaul base station, and transmitting an indication of the detected link degradation to the backhaul base station.
[0057] The indication of link degradation may be transmitted in a PDU session related NGAP message.
[0058] The NGAP message includes a NGAP PDU SESSION RESOURCE NOTIFY message, a NGAP UL PDU SESSION INFORMATION message, a NGAP DL PDU SESSION INFORMATION message, a NGAP UE context management message, or a NGAP interface management message.
[0059] In some embodiments, the indication of link degradation may be transmitted via XnAP signalling.
[0060] The indication may relate to a specific PDU session of a UE served by the wireless base station and/or to a plurality of PDU sessions served by the wireless base station and/or to a plurality of UEs served by the wireless base station.
[0061] The indication may include information about whether an access link between the wireless base station and a user equipment, or the wireless backhaul link, or both, are experiencing degradation. [0062] The indication may include information about a cause of the degradation and/or a condition of the wireless backhaul link.
[0063] The indication may include information about a PDU session or UE affected by the link degradation, and/or a QoS requirement of the PDU session affected by the link degradation.
[0064] The wireless base station may include a WAB-gNB and a WAB-MT. Detecting link degradation in the wireless backhaul link between the wireless base station and the backhaul base station may be performed by the WAB-MT. Transmitting the indication of link degradation in the wireless backhaul link to the backhaul base station may be performed by the WAB-MT.
[0065] The indication may include a pointer to a pre-configured degradation cause, degradation event or degradation level.
[0066] The method may further include obtaining user data, and forwarding the user data to a host or a user equipment.
[0067] The network node may be a UE served by the wireless base station.
BRIEF DESCRIPTION OF THE DRAWINGS
[0068] Figure 1 illustrates a Wireless Access and Backhaul architecture.
[0069] Figure 2 illustrates a protocol stack for the NG interface.
[0070] Figure 3 illustrates a protocol stack for the NG User Plane.
[0071] Figure 4 illustrates a 5G User Plane.
[0072] Figures 5, 6 and 7 illustrate operations of network nodes according to some embodiments.
[0073] Figure 8 shows an example of a communication system in accordance with some embodiments.
[0074] Figure 9 shows a UE in accordance with some embodiments.
[0075] Figure 10 shows a network node in accordance with some embodiments.
DETAILED DESCRIPTION OF EMBODIMENTS
[0076] According to the discussions so far, a WAB node will likely consist of a WAB-gNB and a WAB-MT (i.e., WAB-UE). The WAB-gNB part of an WAB node serves UEs, while the node uses its WAB-MT part to connect with a mobile network (the black BH- gNB in Figure 1). PDU Session(s) of the WAB-MT provide IP connectivity for the WAB- gNB. In this architecture, the PDU session(s) established between the WAB-MT and the BH- UPF (see Fig. 1) are used to provide IP connectivity for NGAP and XnAP connections of the WAB-gNB, as well as to provide connectivity to the operations and management (OAM) function. The WAB-gNB may connect to the same AMF and core network (CN) functions as the WAB-MT (and BH-gNB), or it may connect to different AMF(s) and CN functions.
[0077] According to the above, all traffic from the WAB-gNB (including at least the NG, and Xn communication for interface management and individual UE signaling and UP traffic, OAM connection traffic) will be backhauled through PDU sessions that are established between the WAB-MT and BH-5GC. Consequently, the traffic to/from the UEs served by the WAB-gNB will traverse two wireless links:
• The first link between the BH-gNB and the WAB-MT, i.e., the backhaul (BH) link (NR BH).
• The second link between the WAB-gNB and the UE, i.e., the access link (NR Access).
[0078] With respect to handling the failures and congestion on the BH and access link in the WAB architecture, we note the following:
• In WAB scenarios, if the NR BH link between the BH-gNB and the WAB-MT is in bad (poor coverage) conditions, all PDU sessions of the WAB-MT carrying the traffic to and from the WAB-gNB will be affected.
• Some examples of counter measures that can be taken by the network are the reconfiguration of radio resources, handover of the WAB-MT or throttling of traffic towards the UEs.
• In the scenario of interest, there are multiple control loops: o Radio resources on the NR BH link are under the control of the BH-gNB. o Radio resources on the NR Access link are under the control of the WAB- gNB. o The PDU sessions of the WAB-MT are under the control of BH-5GC. o UE data traffic flow is under control of the UE-5GC which can throttle the traffic, if needed.
[0079] Several issues arise from the above. First, when the NR BH wireless link deteriorates, the core network (CN) nodes serving the WAB-gNB (UE-5GC in Figure 1) should be informed about the degradation because the UE-5GC oversees UE PDU sessions, where link degradation may imply that the configured QoS of PDU sessions cannot be fulfilled anymore (note that in legacy network, there is no BH link, the only wireless link on the path to the UE is the access link). Obviously, the WAB-MT, that terminates the NR BH link is aware of link degradation. As of today, the BH-gNB may inform the BH-5GC via NGAP signalling about whether the QoS of WAB-MT’ s PDU sessions is fulfilled, which may reflect BH link degradation. However, if the CN nodes serving the WAB-gNB are different from the CN nodes serving the WAB-MT, the UE-5GC nodes are unaware about the degradation of the BH link.
[0080] Second, an implication of the WAB architecture is that there exist several control loops that need to be used in a synchronized way to handle bad (poor) channel conditions. Moreover, these control loops are overlapping. For example, the BH link carries UE traffic for the PDU sessions established between the access UEs and the UE-5GC. However, these PDU sessions are carried inside PDU sessions of the WAB-MT, established between the WAB-MT and the BH-5GC. Finally, the radio resources on the BH link between the BH-gNB and the WAB-MT are under the control of the BH-gNB. As of today, it is unclear how these control loops should interact when the BH link is experiencing problems, e.g., failures or bad channel conditions.
[0081] Third, the existing tools defined for PDU session management (e.g., on NG interface) are not suitable for dealing with BH link degradation because:
• The WAB architecture has not yet been specified, meaning that the existing tools against link degradation have not been tailored to the WAB architecture.
• The NG protocol (including NG-C and NG-U) is designed for wired networks. Meanwhile, in WAB architecture the NG traffic is carried over the BH link, which is wireless.
[0082] The existing user plane failure handling can only deal with the GTP-U failure by using Error Indication defined for the GTP-U protocol in 3GPP TS 29.281. For the UEs, this indication would be sent to the UE-5GC. In that respect, existing tools cannot support handling of BH link degradation in WAB architecture. For example, the existing indication pertains to failure, rather than link degradation. This means that, as of today, it is not possible to indicate that the cause of problems is wireless NR BH link degradation. Also, the recovery procedure from poor BH link conditions is not specified in the current 3GPP specifications.
[0083] Fourth, given the architecture of the BH link, where various types of traffic of the WAB node are carried within WAB-MT’ s PDU session(s), it is, as of today, unclear how to define BH link degradation. [0084] Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges.
[0085] Some embodiments described herein provide methods for addressing degradation of BH and/or access link in WAB scenarios. In particular, in some embodiments, the relevant core network nodes are informed about link degradation and the corresponding interaction of the involved nodes and control loops in dealing with it.
[0086] In one solution (WAB-MT triggered solution), when the WAB-MT experiences changes or degradation radio conditions (e.g., including events like RLF), the WAB-MT provides an indication of BH link degradation to the WAB-gNB. The WAB-gNB can also detect BH link degradation by itself (for example by experiencing common changes/reduces throughput in access UE data queues). a. The WAB-gNB can further send the indication of BH link degradation (e.g., pertaining to an existing access PDU session using UL PDU session control information) to the UE-5GC, to indicate the problems with PDU sessions related to the co-located WAB-MT. The indication is sent via user plane signaling. b. The WAB-gNB can send the indication using control plane signaling. c. The indication can be sent by using new or existing messages. d. The indication(s) can be sent with different granularities - they can, e.g., pertain to a PDU session, UE, group of UEs, a wireless link or entire interface. e. The indications may also contain a quantification or a score of link degradation, e.g., a score 1-10, where “1” corresponds to minor degradation and “10” corresponds to serious degradation. f. The UE-5GC refers mainly to the AMF, SMF and UPF functions.
[0087] In another solution (network/BH-gNB triggered solution), the BH-gNB detects NR BH link degradation (by itself, or via a notification from the WAB-MT) and it notifies the BH-5GC, e.g., the AMF and/or the SMF and/or UPF accordingly. The BH-SMF, based on the indication, for example “BH poor condition indication” or “BH is broken”, can perform one or more of the following: a. Decide to release the BH PDU session(s). b. Modify BH PDU Session QoS requirements. c. Determine to offload the BH PDU sessions. d. Informs the BH-AMF, who may connect to the AMF in the UE-5GC and informs it that the BH link between the given BH-gNB and WAB-MT has issues. The AMF/SMF in the UE-5GC may trigger throttling mechanism to limit the Access PDU sessions via the WAB-gNB.
[0088] Meanwhile, the BH-gNB can perform one or more of the following: a. The BH-gNB may upon the detection or information of the “poor BH condition” perform “handover” to move the WAB-MT/BH PDU sessions to another BH-gNB. b. The BH-gNB and/or BH-5GC nodes can make sure that no more UEs use WAB BH, or they can prioritize the BH PDU session by either giving it increased priority or throttling other PDU sessions (e.g., PDU sessions of UEs served in addition to the WAB-MT by the BH-gNB).
[0089] Finally, the BH-5GC may also notify the UE-5GC nodes about the degradation and take actions similar to what is described in first solution (WAB-MT triggered solution) where UE-5GC receives information effectively from WAB-gNB.
[0090] Certain embodiments may provide one or more of the following technical advantage(s).
[0091] Some embodiments may enable informing the network about bad link conditions on the backhaul, which may help the network to deal with poor conditions on the backhaul link and fulfill the QoS that was configured.
[0092] 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.
[0093] The embodiments described herein are presented on a non-limiting example of WAB nodes, but may apply to any kind of moving RAN node or any RAN node that uses wireless backhaul. The described embodiments may apply to both NG and Xn interface connections as well as for the connection between the WAB-gNB and the 0AM. Depending on the scenario, the term “link degradation” means that either the conditions on the link are only getting worse (but the link can still be used for communication) or the link has completely failed.
[0094] The described embodiments apply to NR as well as future radio access technologies (RATs) such as beyond 3 GPP Rel-18. The procedures used in the embodiments may be class- 1 or class-2 procedures, they may be new procedures or enhancements of existing procedures.
[0095] The expressions “X served by Y” or “X is connected to Y” mean that there is a logical interface connection between network nodes X and Y. In case X is a UE, this means that node X and the RAN node serving the UE have a logical connection associated to this UE.
[0096] Unless stated otherwise, the WAB-MT and the WAB-gNB are co-located, i.e., they are a part of the same WAB node. The WAB-gNB may connect to one or more core network (CN) instances (e.g., one or more AMFs). Among these instances, the CN nodes that serve a UE are referred to as, e.g., “UE’s AMF”, “UE’s UPF” etc.
[0097] Unless stated otherwise, “traffic” refers to both user plane traffic and control plane signaling. The terms “core network”, “5GC” and “CN” are used interchangeably without losing the meaning. The term “core network node” or “BH-5GC node” or “UE-5GC node” may refer to the AMF, UPF, SMF or any other 5GC node serving RAN nodes and/or UEs. All examples described herein are non-limiting in that the description of one embodiment does not preclude the use of any other embodiment.
[0098] The embodiment assumes a scenario in which, for a WAB node, either the BH link or the access link, or both, experience degradation, for whatever reason. The embodiments described herein deal with how to inform different network nodes of this degradation, and how different control loops in the architecture coordinate for mitigating the degradation.
[0099] Trigger conditions for link detecting degradation/link status monitoring
[0100] The BH link or the access link for one or multiple UEs may be monitored in terms of radio channel quality, quality of service (QoS) fulfillment/monitoring and resource utilization.
[0101] In an example, a QoS monitoring mechanism is defined. The UE or the WAB-MT periodically keeps monitoring QoS status for each concerned flow in terms of metrics such as bit rate, latency, jitter, packet loss, transmission error rate, or any other QoS indicator such as Mean opinion score (MOS), etc. For each monitoring QoS metric, there may be associated timer and/or threshold and/or a filtering used in the monitoring configured. When at least one concerned QoS metric/indicator of one or multiple concerned QoS flow/service is decreased beyond a configured threshold, the link may be declared as being deteriorated. When at least one concerned QoS metric/indicator of one or multiple concerned QoS flow/service is increased over another configured threshold, the link may be declared as being recovered.
[0102] In an example, the link radio channel quality is measured in metrics such as reference signal received power (RSRP), reference signal received quality (RSRQ), received signal strength indicator (RSSI), signal to interference plus noise ratio (SINR), signal to interference ratio (SIR), etc. The radio channel quality measurement/monitoring may be performed on one or multiple configured reference signals. When at least one radio channel quality indicator has been decreased below a configured threshold, the link may be declared as being deteriorated.
[0103] In an example, the radio link failure (event) may be triggered for the BH link or an access link when one of the below legacy conditions is met, e.g., timer T310 expiry, the maximum number of radio link control (RLC) retransmissions has been reached and/or handover failure and timer T304 expiry.
[0104] In an example, the resource utilization is monitored. When the occupied resources of a link are above a configured threshold, the link may be declared as being deteriorated.
[0105] Link monitoring can be performed by a UE, the WAB-gNB, or the WAB- MT.
[0106] If the UE monitors an access link, the UE may perform monitoring per QoS flow, radio bearer, or PDU session. Upon detection/declaration of an event (i.e., the link is being deteriorated, failed, or recovered) on an access link according to the above trigger conditions, the UE may inform the WAB-gNB or the WAB-MT of at least one of the below information:
• ID of the UE.
• Event i.e., the link is being deteriorated, failed, or recovered.
• Cause of the event e.g., for what reasons, the event was triggered.
• Concerned traffic/services/radio bearers/PDU sessions and associated QoS requirements/information.
• Any other information listed above in connection with indication of link aggregation, if applicable.
[0107] The UE can first send the information to the WAB-gNB via e.g., dedicated radio resource control (RRC) signaling, medium access control (MAC) CE. The gNB sends the information to the WAB-MT.
[0108] If the WAB-gNB performs monitoring, the WAB-gNB may monitor either one or multiple access links, and/or the BH link. For access links, the WAB-gNB may monitor access links in terms of uplink (UL) or downlink (DL) reception, per QoS flow, radio bearer, PDU session, or per UE. Upon detection/declaration of an event (i.e., the link is being deteriorated, failed, or recovered) on an access link according to the above trigger conditions, the WAB-gNB may inform the WAB-MT of at least one of the below information: • ID of the UE.
• Event i.e., the link is being deteriorated, failed, or recovered.
• Cause of the event e.g., for what reasons, the event was triggered.
• Concerned traffic/services/radio bearers/PDU sessions and associated QoS requirements/information.
• Any other information listed above in connection with indication of link aggregation, if applicable.
[0109] As an example, the WAB-gNB can monitor the BH link via the MT. i.e., the WAB-gNB and the WAB-MT exchanges necessary information related to the BH link. Based on which, the WAB-gNB can indirectly monitor the BH link.
[0110] If the WAB-MT performs monitoring, one or multiple concerned UEs, i.e., the UEs that the indication concerned may be determined by the WAB-gNB or WAB-MT based on at least one of the below conditions:
1) The UE and its traffic/service associated with (most) critical/stringent QoS requirements, e.g., the priority of its traffic/service is above a configured threshold, or QoS requirements of its traffic/service (e.g., delay or transmission reliability) is below a configured threshold.
2) The UE which offers high traffic load/data volume on the BH link or the access link.
3) The UE which suffers most due to link degradation.
4) The UE which is associated with worst radio channel quality on the access link.
[OHl] Note that some of the above conditions may be triggered by the WAB-MT based on the information obtained from the WAB-gNB or a UE. Moreover, the number of the concerned UEs which are to be determined, may be configured to the MT by e.g., BH- gNB.
[0112] Upon detection of an event (i.e., the link is being deteriorated, failed, or recovered) on the BH link according to the above trigger conditions, the WAB-MT may inform the WAB-gNB or one or multiple concerned UEs of at least one of the below information:
• ID of the UE.
• Event i.e., the BH link is being deteriorated, failed, or recovered.
• Cause of the event e.g., for what reasons, the event was triggered.
• Concerned traffic/services/radio bearers/PDU sessions and associated QoS requirements/information. • Any other information listed below in connection with indication of link aggregation, if applicable.
[0113] In case the WAB-MT signals a concerned UE of the above information, the WAB-MT can first send the information to the WAB-gNB. The WAB-gNB further sends the information to the concerned UE via e.g., dedicated RRC signaling, MAC control element (CE).
[0114] Indication of link degradation
[0115] An essential part of the described embodiments is an indication about link degradation, herein referred to as the “indication”. The indication may contain one or more of the following information:
• The information about whether the access or the BH link, or both, are experiencing degradation.
• The information about the cause of degradation, e.g., congestion, radio link failure, bad channel quality (poor coverage).
• The information about whether the indication refers to a PDU session, a UE, a group of served UEs or all UEs served by an interface instance or a node. If needed, the indications thereof can be included. In this case, the corresponding identifiers can also be indicated. For example, if the indication pertains to one or more UEs, the ID(s) of the UE(s). Associated QoS requirements/information can also be included.
• Event indication i.e., the link is being deteriorated, failed, or recovered from failure (i.e., that the link is in a good condition again). Cause of the event e.g., for what reasons, the event was triggered.
[0116] The indication may refer to downlink, uplink or both uplink and downlink traffic. The indication can pertain to one or more PDU sessions, links, UEs, groups of UEs, or interface instances. Any of the above listed information to be included in the indication is appliable to any embodiment presented herein.
[0117] Main Embodiment 1: The indication sent from the WAB-gNB
[0118] In this embodiment, the WAB-gNB can send the indication to one or more other network nodes (RAN and/or CN nodes).
[0119] In one embodiment, the WAB-gNB can send an indication containing one or more information listed above to one or more network nodes (e.g., CN nodes).
[0120] In one embodiment, the WAB-gNB can insert an indication into an existing defined PDU-session-related NGAP message (e.g, NGAP PDU SESSION RESOURCE NOTIFY message or NGAP UL PDU SESSION INFORMATION message), or a newly defined message. The indication can pertain to a specific PDU session of a UE. The indication may be sent separately for each PDU session subject to the indication. In addition, the receiving node may, based on the content of the indication, conclude that the notification pertains to all the PDU sessions of the corresponding UE or the WAB-MT - this may be inferred because the same BH link carries all PDU sessions for a UE, which means that all PDU sessions carried over the link will be affected by the degradation.
[0121] In one embodiment, the WAB-gNB can insert an indication into an existing or a newly defined NGAP UE context management message. The indication can pertain to all traffic of the indicated UE. The indication may be sent separately for each UE subject to the indication. In addition, the receiving node may, based on the content of the indication, conclude that the notification pertains to all the UEs served by this WAB-gNB and the CN node - this may be inferred because the same BH link carries all UE traffic to/from the WAB- gNB, which means that traffic of all UEs carried over the link may be affected by the degradation.
[0122] In one embodiment, the WAB-gNB can insert an indication into an existing or a newly defined NGAP interface management message. The indication can pertain to all UEs associated to this NG interface instance of the WAB-gNB. In addition, the receiving node may, based on the content of the indication, conclude that the notification pertains to the entire WAB-node, i.e., to all NG interface instances of the WAB-node - this may be inferred because the same BH link carries all UE traffic to/from the WAB-gNB, which means that all traffic over the BH link may be affected by the degradation. Alternatively, the indication is sent for each NG interface instance subject to the indication. In one sub-variant, the indication may explicitly state “all UEs”.
[0123] In some embodiments, the indication can be sent by using control plane signalling, in some embodiments it can be sent by using user plane signalling.
[0124] In some embodiments, the WAB-gNB can collect or infer by itself the information to be included in the indication. In some embodiments, it may receive the information from one or more different network nodes, from the WAB-MT and/or from UEs.
[0125] For example, the WAB-gNB can receive the information about BH link degradation from the WAB-MT or from the BH-gNB.
[0126] In some embodiments the WAB-gNB sends an indication to one or more CN nodes serving the UEs (e.g., AMFs). To prevent the failure of the NG connection between WAB-gNB and CN due to link degradation, network nodes may execute one or more of the following actions. [0127] The WAB-gNB and the AMF(s) may prioritize the sending of NG control plane traffic and the SCTP traffic (e.g., heartbeat messages and pings), so that the NG connection does not fail.
[0128] The WAB-gNB may reduce the amount of traffic at the NG and/or Uu interfaces, by e.g., prioritizing traffic and disconnecting low-priority traffic, so that the remaining available bandwidth is used for control plane traffic.
[0129] In some embodiments, the WAB-gNB can send the indication to one or more BH-5GC nodes. This may happen, if the WAB-MT and WAB-gNB are served by the same CN nodes. In some embodiments, the WAB-gNB can send the indication to the BH- gNB. In some variants, the WAB-gNB can send the indication to the WAB-MT, and the WAB-MT can pass it to the BH-gNB via RRC signalling. In some variants, the WAB-gNB can send the indication to the BH-gNB via XnAP signalling or via NGAP signalling.
[0130] In some embodiments, the WAB-gNB can send the indication to the source of the user data in the user plane, e.g., the application server. In some variant the WAB-gNB applies AQM to trigger the application server to reduce the amount of traffic
[0131] Main Embodiment 2: The indication sent from the BH-gNB
[0132] In this embodiment, the BH-gNB sends the indication to one or more other network nodes (e.g., CN nodes). The embodiments defined in Embodiment 1 can be reused, with some differences. In particular, in some cases, the indication may refer to one or more PDU sessions of the WAB-MT, which carry the traffic of the WAB-node (in Embodiment 1 it may refer to the PDU sessions of UEs). If the indication is UE-associated (e.g., if the NGAP UE context management signalling is used to deliver the indication), the signalling used is associated to the WAB-MT.
[0133] In some cases, it may happen that the WAB-gNB is unable to send the indication, e.g., due to the bad state of the BH link (because the indication needs to traverse the BH link itself). Given that the BH-gNB serves the WAB-MT and is hence in control of the radio resources for the BH link, the BH-gNB has an overview about the state of the BH link, and it can send the indication to relevant CN nodes, instead and/or in addition to the WAB-gNB.
[0134] In some embodiments, the indication can be sent by the BH-gNB to one or more BH-5GC nodes, and these BH-5GC nodes can forward the indication to one or more UE-5GC nodes.
[0135] In some embodiments, the indication can be sent by the BH-gNB to one or more UE-5GC nodes, and/or one or more CN nodes connected to the WAB-gNB. [0136] This embodiment can be used in conjunction with the other embodiments described herein, where applicable.
[0137] Main Embodiment 3: Indication sent to the served UEs
[0138] According to the trigger conditions for link detecting degradation/link status monitoring described above, the WAB-MT or the WAB-gNB may detect an event on the BH link (e.g., the BH link is deteriorating, failed, or recovered), the WAB-MT or the WAB-gNB may inform one or multiple concerned UEs/affected UEs of at least one of the below information:
• ID of the UE.
• Event i.e., the BH link is being deteriorated, failed, or recovered.
• Cause of the event e.g., for what reasons, the event was triggered.
• Concerned traffic/services/radio bearers/PDU sessions and associated QoS requirements/information.
• Any other information listed above in connection with indication of link aggregation, if applicable.
[0139] In addition, a UE may detect an event on an access link (e.g., the link is deteriorating, failed, or recovered) by itself or being informed by the WAB-gNB, the UE may perform at least one of the below actions.
[0140] The UE may send a signaling (e.g., NAS signaling) to the CN indicating the event. The signaling may carry the same information as in the above. In one option, the signaling may just carry the indicators. In another option, the signaling may also carry indicators requesting the concerned PDU sessions/traffic/flows to be throttled due to bad radio channel condition from the network. In another option, the signaling may also carry indicators requesting the concerned PDU sessions/traffic/flows to release throttling due to good radio channel condition from the network.
[0141] The UE may adjust data rate or scheduling transmissions between radio bearers/QoS flows. The UE may perform the above action especially for UE scheduled/autonomously triggered transmissions (e.g., perform adjustment or scheduling adjustment for configured grant-based transmissions, perform adjustment in the logical channel prioritization procedure). In case the link is being deteriorated or failed, the UE may slow down data transmissions mapped to the BH link. In case the link is being deteriorated or failed, the UE may down-prioritize the transmissions with higher priority. In other words, the UE may avoid/slow down transmissions with higher priority, to avoid those transmissions being negatively affected due to bad radio channel conditions. In case the link is being recovered, the UE may increase data transmissions mapped to the BH link. In case the link is being recovered, the UE may prioritize the transmissions with higher priority. In other words, the UE may increase/ speed up transmissions with higher priority, to ensure transmissions with higher priority to be better served.
[0142] Main Embodiment 4: Combination of Main Embodiment 1 and Main Embodiment 2
[0143] In some embodiments, when the WAB-gNB detects BH link degradation, in addition to informing the UE-5GC, it can inform the BH-gNB (via the WAB-MT, via RRC or Xn or NG signalling) about it, so that the BH-gNB informs the BH-5GC.
[0144] In some embodiments, when the WAB-MT or the WAB-gNB detects BH link degradation, in addition to informing the BH-5GC, it can inform the WAB-gNB about it, so that the WAB-gNB informs the UE-5GC.
[0145] In some embodiments, after receiving the indication from the BH-gNB, the BH-5GC node sends the indication to one or more UE-5GC nodes.
[0146] In some embodiments, after receiving the indication from the WAB-gNB, the UE-5GC node sends the indication to one or more BH-5GC nodes.
[0147] Common to Main Embodiments 1, 2, and 4, when the BH-gNB informs network functions or nodes with information, based on information (partially or fully) provided by the WAB-gNB, the BH-gNB and/or the WAB-gNB might be pre-configured with information on different indications, such as causes, events, degradation levels etc., or combinations thereof. In this case, the signaling from WAB-gNB to BH-gNB (or vice versa), potentially via WAB-MT or Xn, can be reduced to signaling a pointer to such (combinations of) indications. This could greatly reduce the required signaling information amount, equivalent to the actually exchanged information, in cases any link between WAB-gNB and the BH-gNB is in deteriorated conditions.
[0148] Aspects related to RLF handling on the BH link
[0149] In case there is Radio Link Failure (RLF) on the BH link, it may happen that the NGAP layer at the AMF with which the WAB-gNB has an NG connection, or the underlying SCTP layer, times out and the AMF tears down the NGAP connection. As per legacy specifications for the UE, the WAB-MT may attempt to recover from the RLF, and, once it succeeds, it may notify the WAB-gNB about the successful recovery, which may serve as a trigger for the WAB-gNB to set up the NG connectivity to the CN again.
[0150] Figure 5 illustrates operations of a network node according to some embodiments. In some embodiments, the network node is a wireless base station that has a wireless backhaul connection to a backhaul base station, and the method includes detecting link degradation in a wireless backhaul link between the wireless base station and the backhaul base station (block 502), and transmitting an indication of link degradation to a network node in the wireless communication network (block 504).
[0151] The network node may include a core network node in a core network of the wireless communication network.
[0152] The indication of link degradation may be transmitted in a packet data unit, PDU, session related next generation application protocol, NGAP, message.
[0153] The NGAP message may include an NGAP PDU SESSION RESOURCE NOTIFY message, an NGAP UL PDU SESSION INFORMATION message, an NGAP UE context management message or an NGAP interface management message.
[0154] The indication may relate to a specific PDU session of a user equipment, UE, served by the wireless base station or to all PDU sessions served by the wireless base station. The indication may be sent by user plane messaging or control plane messaging.
[0155] The indication may include information about whether an access link between the wireless base station and a user equipment, or the wireless backhaul link, or both, are experiencing degradation.
[0156] The indication may include information about a cause of the degradation and/or a condition of the wireless backhaul link.
[0157] The indication may include information about a PDU session or UE affected by the link degradation, and/or a quality of service, QoS, requirement of the PDU session affected by the link degradation.
[0158] The wireless base station may include a WAB gNodeB (WAB-gNB) and a WAB mobile termination (WAB-MT), and detecting link degradation in the wireless backhaul link between the wireless base station and the backhaul base station may be performed by the WAB-MT.
[0159] In some embodiments, the WAB-MT notifies the WAB-gNB of the link degradation in the wireless backhaul link between the wireless base station and the backhaul base station, and the WAB-gNB initiates the transmitting of the indication of link degradation to the network node.
[0160] In some embodiments, the WAB-gNB initiates the transmitting of the indication of link degradation to the network node via the WAB-MT, and the WAB-MT transmits the indication of link degradation to the network node via radio resource control, RRC, signalling. [0161] The WAB-gNB may initiate the transmitting of the indication of link degradation to the network node via XnAP or NGAP signalling.
[0162] In some embodiments, the WAB-MT applies active queue management to reduce an amount of traffic over the wireless backhaul in response to detecting link degradation in the wireless backhaul link between the wireless base station and the backhaul base station.
[0163] The network node may include a backhaul gNodeB, BH-gNB, that serves the WAB-MT, a network function of a backhaul core network, BH-CN, that serves the WAB- MT, or a network function of a UE core network, UE-CN, that serves a UE that is connected to the WAB-gNB.
[0164] In some embodiments, the network node includes a UE served by the wireless base station. The method may further include sending a further indication of the link degradation to a network node in a core network serving the wireless base station or the UE.
[0165] The further indication may request throttling of traffic carried by the wireless backhaul link or adjustment of a data rate, a priority or scheduling of bearers carried by the wireless backhaul link.
[0166] Referring to Figure 6, in some embodiments, the method is performed by the backhaul base station and the method includes detecting link degradation in a wireless backhaul link between the wireless base station and the backhaul base station (block 602), and transmitting an indication of link degradation to a network node in the wireless communication network (block 604).
[0167] Referring to Figure 7, in some embodiments, a method is performed by a wireless base station in a wireless communication network. The wireless base station has a wireless backhaul connection to a backhaul base station. The method includes detecting link degradation in a wireless backhaul link between the wireless base station and the backhaul base station (block 702), and transmitting an indication of the detected link degradation to the backhaul base station (block 704).
[0168] Figure 8 shows an example of a communication system 800 in accordance with some embodiments.
[0169] In the example, the communication system 800 includes a telecommunication network 802 that includes an access network 804, such as a radio access network (RAN), and a core network 806, which includes one or more core network nodes 808. The access network 804 includes one or more access network nodes, such as network nodes 810a and 810b (one or more of which may be generally referred to as network nodes 810), or any other similar 3rd Generation Partnership Project (3GPP) access nodes or non- 3GPP access points. Moreover, as will be appreciated by those of skill in the art, a network node is not necessarily limited to an implementation in which a radio portion and a baseband portion are supplied and integrated by a single vendor. Thus, it will be understood that network nodes include disaggregated implementations or portions thereof. For example, in some embodiments, the telecommunication network 802 includes one or more Open-RAN (ORAN) network nodes. An ORAN network node is a node in the telecommunication network 802 that supports an ORAN specification (e.g., a specification published by the O- RAN Alliance, or any similar organization) and may operate alone or together with other nodes to implement one or more functionalities of any node in the telecommunication network 802, including one or more network nodes 810 and/or core network nodes 808.
[0170] Examples of an ORAN network node include an open radio unit (O-RU), an open distributed unit (O-DU), an open central unit (O-CU), including an O-CU control plane (O-CU-CP) or an O-CU user plane (O-CU-UP), a RAN intelligent controller (near-real time or non-real time) hosting software or software plug-ins, such as a near-real time control application (e.g., xApp) or a non-real time control application (e.g., rApp), or any combination thereof (the adjective “open” designating support of an ORAN specification). The network node may support a specification by, for example, supporting an interface defined by the ORAN specification, such as an Al, Fl, Wl, El, E2, X2, Xn interface, an open fronthaul user plane interface, or an open fronthaul management plane interface. Moreover, an ORAN access node may be a logical node in a physical node. Furthermore, an ORAN network node may be implemented in a virtualization environment (described further below) in which one or more network functions are virtualized. For example, the virtualization environment may include an O-Cloud computing platform orchestrated by a Service Management and Orchestration Framework via an O-2 interface defined by the O- RAN Alliance or comparable technologies. The network nodes 810 facilitate direct or indirect connection of user equipment (UE), such as by connecting UEs 812a, 812b, 812c, and 812d (one or more of which may be generally referred to as UEs 812) to the core network 806 over one or more wireless connections.
[0171] Example wireless communications over a wireless connection include transmitting and/or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and/or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, the communication system 800 may include any number of wired or wireless networks, network nodes, UEs, and/or any other components or systems that may facilitate or participate in the communication of data and/or signals whether via wired or wireless connections. The communication system 800 may include and/or interface with any type of communication, telecommunication, data, cellular, radio network, and/or other similar type of system.
[0172] The UEs 812 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and/or operable to communicate wirelessly with the network nodes 810 and other communication devices. Similarly, the network nodes 810 are arranged, capable, configured, and/or operable to communicate directly or indirectly with the UEs 812 and/or with other network nodes or equipment in the telecommunication network 802 to enable and/or provide network access, such as wireless network access, and/or to perform other functions, such as administration in the telecommunication network 802.
[0173] In the depicted example, the core network 806 connects the network nodes 810 to one or more hosts, such as host 816. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. The core network 806 includes one more core network nodes (e.g., core network node 808) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and/or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 808. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-concealing function (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and/or a User Plane Function (UPF).
[0174] The host 816 may be under the ownership or control of a service provider other than an operator or provider of the access network 804 and/or the telecommunication network 802, and may be operated by the service provider or on behalf of the service provider. The host 816 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio/video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.
[0175] As a whole, the communication system 800 of Figure 8 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and/or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and/or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and/or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox.
[0176] In some examples, the telecommunication network 802 is a cellular network that implements 3GPP standardized features. Accordingly, the telecommunications network 802 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network 802. For example, the telecommunications network 802 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and/or Massive Machine Type Communication (mMTC)/Massive loT services to yet further UEs.
[0177] In some examples, the UEs 812 are configured to transmit and/or receive information without direct human interaction. For instance, a UE may be designed to transmit information to the access network 804 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 804. Additionally, a UE may be configured for operating in single- or multi-RAT or multistandard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR (New Radio) and LTE, i.e. being configured for multi -radio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC).
[0178] In the example, the hub 814 communicates with the access network 804 to facilitate indirect communication between one or more UEs (e.g., UE 812c and/or 812d) and network nodes (e.g., network node 810b). In some examples, the hub 814 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 814 may be a broadband router enabling access to the core network 806 for the UEs. As another example, the hub 814 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 810, or by executable code, script, process, or other instructions in the hub 814. As another example, the hub 814 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub 814 may be a content source. For example, for a UE that is a VR headset, display, loudspeaker or other media delivery device, the hub 814 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 814 then provides to the UE either directly, after performing local processing, and/or after adding additional local content. In still another example, the hub 814 acts as a proxy server or orchestrator for the UEs, in particular if one or more of the UEs are low energy loT devices.
[0179] The hub 814 may have a constant/persistent or intermittent connection to the network node 810b. The hub 814 may also allow for a different communication scheme and/or schedule between the hub 814 and UEs (e.g., UE 812c and/or 812d), and between the hub 814 and the core network 806. In other examples, the hub 814 is connected to the core network 806 and/or one or more UEs via a wired connection. Moreover, the hub 814 may be configured to connect to an M2M service provider over the access network 804 and/or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 810 while still connected via the hub 814 via a wired or wireless connection. In some embodiments, the hub 814 may be a dedicated hub - that is, a hub whose primary function is to route communications to/from the UEs from/to the network node 810b. In other embodiments, the hub 814 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 810b, but which is additionally capable of operating as a communication start and/or end point for certain data channels.
[0180] Figure 9 shows a UE 900 in accordance with some embodiments. As used herein, a UE refers to a device capable, configured, arranged and/or operable to communicate wirelessly with network nodes and/or other UEs. Examples of a UE include, but are not limited to, a smart phone, mobile phone, cell phone, voice over IP (VoIP) phone, wireless local loop phone, desktop computer, personal digital assistant (PDA), wireless cameras, gaming console or device, music storage device, playback appliance, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), smart device, wireless customer-premise equipment (CPE), vehicle, vehicle-mounted or vehicle embedded/integrated wireless device, etc. Other examples include any UE identified by the 3rd Generation Partnership Project (3GPP), including a narrow band internet of things (NB-IoT) LIE, a machine type communication (MTC) UE, and/or an enhanced MTC (eMTC) UE.
[0181] A UE may support device-to-device (D2D) communication, for example by implementing a 3 GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), or vehicle-to-everything (V2X). In other examples, a UE may not necessarily have a user in the sense of a human user who owns and/or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).
[0182] The UE 900 includes processing circuitry 902 that is operatively coupled via a bus 904 to an input/output interface 906, a power source 908, a memory 910, a communication interface 912, and/or any other component, or any combination thereof. Certain UEs may utilize all or a subset of the components shown in Figure 9. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.
[0183] The processing circuitry 902 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored as machine-readable computer programs in the memory 910. The processing circuitry 902 may be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general-purpose processors, such as a microprocessor or digital signal processor (DSP), together with appropriate software; or any combination of the above. For example, the processing circuitry 902 may include multiple central processing units (CPUs). [0184] In the example, the input/output interface 906 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and/or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into the UE 900. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.
[0185] In some embodiments, the power source 908 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic device, or power cell, may be used. The power source 908 may further include power circuitry for delivering power from the power source 908 itself, and/or an external power source, to the various parts of the UE 900 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging of the power source 908. Power circuitry may perform any formatting, converting, or other modification to the power from the power source 908 to make the power suitable for the respective components of the UE 900 to which power is supplied.
[0186] The memory 910 may be or be configured to include memory such as random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, the memory 910 includes one or more application programs 914, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 916. The memory 910 may store, for use by the UE 900, any of a variety of various operating systems or combinations of operating systems.
[0187] The memory 910 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as tamper resistant module in the form of a universal integrated circuit card (UICC) including one or more subscriber identity modules (SIMs), such as a USIM and/or ISIM, other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUICC), integrated UICC (iUICC) or a removable UICC commonly known as ‘SIM card.’ The memory 910 may allow the UE 900 to access instructions, application programs and the like, stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied as or in the memory 910, which may be or comprise a device-readable storage medium.
[0188] The processing circuitry 902 may be configured to communicate with an access network or other network using the communication interface 912. The communication interface 912 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 922. The communication interface 912 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another UE or a network node in an access network). Each transceiver may include a transmitter 918 and/or a receiver 920 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, the transmitter 918 and receiver 920 may be coupled to one or more antennas (e.g., antenna 922) and may share circuit components, software or firmware, or alternatively be implemented separately.
[0189] In the illustrated embodiment, communication functions of the communication interface 912 may include cellular communication, Wi-Fi communication, LPWAN communication, data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented in according to one or more communication protocols and/or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission control protocol/internet protocol (TCP/IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.
[0190] Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 912, via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE. The output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., when moisture is detected an alert is sent), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient).
[0191] As another example, a UE comprises an actuator, a motor, or a switch, related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change. For example, the UE may comprise a motor that adjusts the control surfaces or rotors of a drone in flight according to the received input or to a robotic arm performing a medical procedure according to the received input.
[0192] A UE, when in the form of an Internet of Things (loT) device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology, extended industrial application and healthcare. Non-limiting examples of such an loT device are a device which is or which is embedded in: a connected refrigerator or freezer, a TV, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a home security camera, a motion detector, a thermostat, a smoke detector, a door/window sensor, a flood/moisture sensor, an electrical door lock, a connected doorbell, an air conditioning system like a heat pump, an autonomous vehicle, a surveillance system, a weather monitoring device, a vehicle parking monitoring device, an electric vehicle charging station, a smart watch, a fitness tracker, a head-mounted display for Augmented Reality (AR) or Virtual Reality (VR), a wearable for tactile augmentation or sensory enhancement, a water sprinkler, an animal- or item-tracking device, a sensor for monitoring a plant or animal, an industrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. A UE in the form of an loT device comprises circuitry and/or software in dependence of the intended application of the loT device in addition to other components as described in relation to the UE 900 shown in Figure 9. [0193] As yet another specific example, in an loT scenario, a UE may represent a machine or other device that performs monitoring and/or measurements, and transmits the results of such monitoring and/or measurements to another UE and/or a network node. The UE may in this case be an M2M device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the UE may implement the 3GPP NB-IoT standard. In other scenarios, a UE may represent a vehicle, such as a car, a bus, a truck, a ship and an airplane, or other equipment that is capable of monitoring and/or reporting on its operational status or other functions associated with its operation.
[0194] In practice, any number of UEs may be used together with respect to a single use case. For example, a first UE might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second UE that is a remote controller operating the drone. When the user makes changes from the remote controller, the first UE may adjust the throttle on the drone (e.g. by controlling an actuator) to increase or decrease the drone’s speed. The first and/or the second UE can also include more than one of the functionalities described above. For example, a UE might comprise the sensor and the actuator, and handle communication of data for both the speed sensor and the actuators.
[0195] Figure 10 shows a network node 1000 in accordance with some embodiments. As used herein, network node refers to equipment capable, configured, arranged and/or operable to communicate directly or indirectly with a UE and/or with other network nodes or equipment, in a telecommunication network. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs) and NR. NodeBs (gNBs)), 0-RAN nodes or components of an 0-RAN node (e g., 0-RU, 0-DU, O-CU).
[0196] Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units, distributed units (e.g., in an O- RAN access node) and/or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS). [0197] Other examples of network nodes include multiple transmission point (multi-TRP) 5G access nodes, multi-standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi- cell/multicast coordination entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and/or Minimization of Drive Tests (MDTs).
[0198] The network node 1000 includes a processing circuitry 1002, a memory 1004, a communication interface 1006, and a power source 1008. The network node 1000 may be composed of multiple physically separate components (e.g., a NodeB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which the network node 1000 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, the network node 1000 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memory 1004 for different RATs) and some components may be reused (e.g., a same antenna 1010 may be shared by different RATs). The network node 1000 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 1000, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 1000.
[0199] The processing circuitry 1002 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and/or encoded logic operable to provide, either alone or in conjunction with other network node 1000 components, such as the memory 1004, to provide network node 1000 functionality.
[0200] In some embodiments, the processing circuitry 1002 includes a system on a chip (SOC). In some embodiments, the processing circuitry 1002 includes one or more of radio frequency (RF) transceiver circuitry 1012 and baseband processing circuitry 1014. In some embodiments, the radio frequency (RF) transceiver circuitry 1012 and the baseband processing circuitry 1014 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry 1012 and baseband processing circuitry 1014 may be on the same chip or set of chips, boards, or units.
[0201] The memory 1004 may comprise any form of volatile or non-volatile computer-readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or any other volatile or non-volatile, non-transitory device-readable and/or computer-executable memory devices that store information, data, and/or instructions that may be used by the processing circuitry 1002. The memory 1004 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and/or other instructions capable of being executed by the processing circuitry 1002 and utilized by the network node 1000. The memory 1004 may be used to store any calculations made by the processing circuitry 1002 and/or any data received via the communication interface 1006. In some embodiments, the processing circuitry 1002 and memory 1004 is integrated.
[0202] The communication interface 1006 is used in wired or wireless communication of signaling and/or data between a network node, access network, and/or UE. As illustrated, the communication interface 1006 comprises port(s)/terminal(s) 1016 to send and receive data, for example to and from a network over a wired connection. The communication interface 1006 also includes radio front-end circuitry 1018 that may be coupled to, or in certain embodiments a part of, the antenna 1010. Radio front-end circuitry 1018 comprises filters 1020 and amplifiers 1022. The radio front-end circuitry 1018 may be connected to an antenna 1010 and processing circuitry 1002. The radio front-end circuitry may be configured to condition signals communicated between antenna 1010 and processing circuitry 1002. The radio front-end circuitry 1018 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. The radio front-end circuitry 1018 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 1020 and/or amplifiers 1022. The radio signal may then be transmitted via the antenna 1010. Similarly, when receiving data, the antenna 1010 may collect radio signals which are then converted into digital data by the radio front-end circuitry 1018. The digital data may be passed to the processing circuitry 1002. In other embodiments, the communication interface may comprise different components and/or different combinations of components.
[0203] In certain alternative embodiments, the network node 1000 does not include separate radio front-end circuitry 1018, instead, the processing circuitry 1002 includes radio front-end circuitry and is connected to the antenna 1010. Similarly, in some embodiments, all or some of the RF transceiver circuitry 1012 is part of the communication interface 1006. In still other embodiments, the communication interface 1006 includes one or more ports or terminals 1016, the radio front-end circuitry 1018, and the RF transceiver circuitry 1012, as part of a radio unit (not shown), and the communication interface 1006 communicates with the baseband processing circuitry 1014, which is part of a digital unit (not shown).
[0204] The antenna 1010 may include one or more antennas, or antenna arrays, configured to send and/or receive wireless signals. The antenna 1010 may be coupled to the radio front-end circuitry 1018 and may be any type of antenna capable of transmitting and receiving data and/or signals wirelessly. In certain embodiments, the antenna 1010 is separate from the network node 1000 and connectable to the network node 1000 through an interface or port.
[0205] The antenna 1010, communication interface 1006, and/or the processing circuitry 1002 may be configured to perform any receiving operations and/or certain obtaining operations described herein as being performed by the network node. Any information, data and/or signals may be received from a UE, another network node and/or any other network equipment. Similarly, the antenna 1010, the communication interface 1006, and/or the processing circuitry 1002 may be configured to perform any transmitting operations described herein as being performed by the network node. Any information, data and/or signals may be transmitted to a UE, another network node and/or any other network equipment.
[0206] The power source 1008 provides power to the various components of network node 1000 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 1008 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 1000 with power for performing the functionality described herein. For example, the network node 1000 may be connectable to an external power source (e.g., the power grid, an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry of the power source 1008. As a further example, the power source 1008 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.
[0207] Embodiments of the network node 1000 may include additional components beyond those shown in Figure 10 for providing certain aspects of the network node’s functionality, including any of the functionality described herein and/or any functionality necessary to support the subject matter described herein. For example, the network node 1000 may include user interface equipment to allow input of information into the network node 1000 and to allow output of information from the network node 1000. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 1000.
[0208] A network node 1000 as illustrated in Figure 10 may be configured to perform operations illustrated in any of Figures 5-7. In particular, some embodiments provide a network node for performing backhaul communications in a wireless communication network. The network node includes processing circuitry 1002 and power supply circuitry 1008 configured to supply power to the processing circuitry 1002.
[0209] Referring to Figures 5 and 10, in some embodiments, the network node 10000 is a wireless base station that has a wireless backhaul connection to a backhaul base station, and the processing circuitry 1002 is configured to detect link degradation in a wireless backhaul link between the wireless base station and the backhaul base station (block 502), and transmit an indication of link degradation to a network node in the wireless communication network (block 504).
[0210] Referring to Figures 6 and 10, in some embodiments, the network node 1000 is a backhaul base station that has a wireless connection to a wireless base station, and the processing circuitry 1002 is configured to detect link degradation in a wireless backhaul link between the wireless base station and the backhaul base station (block 602), and transmit an indication of link degradation to a network node in the wireless communication network (block 604).
[0211] Referring to Figures 7 and 10, in some embodiments, the network node 1000 is a wireless base station that has a wireless connection to a backhaul base station, and the processing circuitry 1002 is configured to detect link degradation in a wireless backhaul link between the wireless base station and the backhaul base station (block 702), and transmit an indication of the detected link degradation to the backhaul base station (block 704). [0212] Although the computing devices described herein (e.g., UEs, network nodes, hosts) may include the illustrated combination of hardware components, other embodiments may comprise computing devices with different combinations of components. It is to be understood that these computing devices may comprise any suitable combination of hardware and/or software needed to perform the tasks, features, functions and methods disclosed herein. Determining, calculating, obtaining or similar operations described herein may be performed by processing circuitry, which may process information by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and/or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination. Moreover, while components are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, computing devices may comprise multiple different physical components that make up a single illustrated component, and functionality may be partitioned between separate components. For example, a communication interface may be configured to include any of the components described herein, and/or the functionality of the components may be partitioned between the processing circuitry and the communication interface. In another example, non-computationally intensive functions of any of such components may be implemented in software or firmware and computationally intensive functions may be implemented in hardware.
[0213] In certain embodiments, some or all of the functionality described herein may be provided by processing circuitry executing instructions stored on in memory, which in certain embodiments may be a computer program product in the form of a non-transitory computer-readable storage medium. In alternative embodiments, some or all of the functionality may be provided by the processing circuitry without executing instructions stored on a separate or discrete device-readable storage medium, such as in a hard-wired manner. In any of those particular embodiments, whether executing instructions stored on a non-transitory computer-readable storage medium or not, the processing circuitry can be configured to perform the described functionality. The benefits provided by such functionality are not limited to the processing circuitry alone or to other components of the computing device, but are enjoyed by the computing device as a whole, and/or by end users and a wireless network generally.
REFERENCES
[1] 3GPP RP -234041 New SID: Study on additional topological enhancements for NR [2] 3GPP TS 29.281 vl8.0.0
[3] 3GPP TS 38.413 vl8.0.0
[4] 3GPP TS 38.410 V18.0.0
[5] 3GPP TS 23.501 V18.4.0 [6] 3GPP TS 23.527 V18.2.0
[7] 3GPP TS 38.415 V18.0.0