Overlapping framed routes for redundancy

Abstract

Support for overlapping framed routes is introduced to provide redundancy without use of overlays. A device-side network (50) connects to the 5GS (10) via two or more UEs (40). The Mobile Network Operator, MNO, configures overlapping framed routes for the UEs (40) so that the address ranges of the connected devices in the device-side network (50) are mapped to a corresponding PDU session at the User Plane Function, UPF (14). The network (12) configures an active path associated with one of the UEs (40). Downlink traffic for the connected devices (54) is forwarded to the active UE. The other UEs provide alternative paths in case the active path fails. If there is a failure in the active path, a formerly inactive UE is promoted to become the new active UE and the downlink traffic for the connected devices (54) is forwarded to the new active UE.

Description

OVERLAPPING FRAMED ROUTES FOR REDUNDANCYTECHNICAL FIELD

[0001] The present disclosure relates generally to framed routing in wireless communication networks and, more particularly, to overlapping framed routes in Fifth Generation (5G) networks for redundancy.BACKGROUND

[0002] The Third Generation Partnership Project (3GPP) for 5G Systems (5GS) supports framed routing for a Packet Data Unit (PDU) session. Framed routing enables multiple connected devices in an Internet Protocol (IP) network behind a user equipment (UE) to be reachable via the same PDU session. The framed routes are the IP routes behind the UE. Each framed route refers to a range of IPv4 addresses or a range of IPv6 prefixes used by the connected devices in the IP network behind the UE, i.e. , the device-side network. A PDU session may be associated with multiple framed routes. The configuration of the framed routes is static and does not change during the lifetime of the PDU session.

[0003] The configuration of the framed routes can be based on subscription information from a Unified Data Management (UDM) function in the core network, or from the Authentication, Authorization and Accounting (AAA) server. Based on the configuration in the UDM or the AAA server, the Session Management Function (SMF) sets up PDRs (Packet Detection Rules) that map the downlink traffic targeting the given address range to the associated PDU session.

[0004] The current 3GPP solution for framed routing does not enable a connected device in the device-side network to be connected to the 5GS via multiple UEs simultaneously. Enabling multiple connections to the 5GS for the UE-side network could provide redundancy in case one of the paths (radio links between the UE and the network) fails. With multiple connections to the 5GS, the connection to the 5GS can still be maintained even if the radio link to one of the UEs fails.

[0005] The use of redundant paths for the device-side networks is only possible today with overlay solutions, e.g., using tunneling between connected devices outside of the 3GPP network and choosing between the tunnels based on keep-alive messages. However, overlay solutions are complex and not suitable for a network operator to offer redundancy as a service provided by the 3GPP network.SUMMARY

[0006] The present disclosure provides support for overlapping framed routes for redundancy without use of overlays. A device-side network connects to the 5GS via two or more UEs. The Mobile Network Operator (MNO) configures overlapping framed routes for the UEs so that the address ranges of the connected devices in the device-side network are mapped to a corresponding PDU session at the User Plane Function (UPF). The network configures an active path associated with one of the UEs. Downlink traffic for the connected devices is forwarded to the active UE. The other UEs provide alternative paths in case the active path fails. If there is a failure in the active path, a formerly inactive UE is promoted to become the new active UE and the downlink traffic for the connected devices is forwarded to the new active UE.

[0007] A first aspect of the disclosure comprises a method implemented by a SMF or other network node supporting overlapping framed routes through two or more user equipments (UEs) to the same device-side network. The method comprises obtaining at least two administrative distance values associated with a framed route in a set of overlapping framed routes belonging to different UEs. Each administrative distance value being associated with a different reachability state of a corresponding one of the UEs. The method further comprises configuring, based on the administrative distance values for the framed routes and the reachability states of the corresponding UEs, a user plane function of the wireless communication network to select a UE associated with one of the framed routes in the set of overlapping framed routes as an active UE for delivering packets to connected devices in the device-side network.

[0008] A second aspect of the disclosure comprises a SMF or other network node supporting overlapping framed routes though two or more user equipment (UEs) to the same device-side network. The network node is configured to obtain at least two administrative distance values associated with a framed route in a set of overlapping framed routes belonging to different UEs. Each administrative distance value being associated with a different reachability state of a corresponding one of the UEs. The network node is further configured to configure, based on the administrative distance values for the framed routes and the reachability states of the corresponding UEs, a user plane function of the wireless communication network to select a UE associated with one of the framed routes in the set of overlapping framed routes as an active UE for delivering packets to connected devices in the device-side network.

[0009] A third aspect of the disclosure comprises a SMF or other network node supporting overlapping framed routes though two or more user equipment (UEs) to the same device-side network. The network node comprises communication circuitry configured for communication with one or more other network nodes and processing circuitry operatively connected to the communication circuitry. The processing circuitry is configured to obtain at least two administrative distance values associated with a framed route in a set of overlapping framed routes belonging to different UEs. Each administrative distance value being associated with a different reachability state of a corresponding one of the UEs. The network node is further configured to configure, based on the administrative distance values for the framed routes and the reachability states of the corresponding UEs, a user plane function of the wireless communication network to select a UE associated with one of the framed routes in the set of overlapping framed routes as an active UE for delivering packets to connected devices in the device-side network.

[0010] A fourth aspect of the disclosure comprises a computer program for a SMF or other network node in a wireless communication system. The computer program comprisesexecutable instructions that, when executed by processing circuitry in the network node, causes the network node to perform the method according to the first aspect.

[0011] A fifth aspect of the disclosure comprises a carrier containing a computer program according to the fourth aspect. The carrier is one of an electronic signal, optical signal, radio signal, or a non-transitory computer readable storage medium.

[0012] A sixth aspect of the disclosure comprises a method implemented by a UPF or other network node supporting overlapping framed routes though two or more user equipment (UEs) to the same device-side network. The method comprises receiving a downlink packet addressed to a connected device in the device-side network. The method further comprises selecting a UE from among a set of UEs associated with different framed routes in a set of overlapping framed routes as an active UE for delivering packets to connected devices in the device-side network. The method further comprises forwarding the downlink packet to the connected device through the active UE.

[0013] A seventh aspect of the disclosure comprises a UPF or other network node supporting overlapping framed routes though two or more user equipment (UEs) to the same device-side network. The network node is configured to receive a downlink packet addressed to a connected device in the device-side network. The network node is further configured to select a UE from among a set of UEs associated with different framed routes in a set of overlapping framed routes as an active UE for delivering packets to connected devices in the device-side network. The network node is further configured forward the downlink packet to the connected device through the active UE.

[0014] An eighth aspect of the disclosure comprises a UPF or other network node supporting overlapping framed routes though two or more user equipment (UEs) to the same device-side network. The network node comprises communication circuitry configured for communication with one or more other network nodes and processing circuitry operatively connected to thecommunication circuitry. The processing circuitry is configured to receive a downlink packet addressed to a connected device in the device-side network. The processing circuitry is further configured to select a UE from among a set of UEs associated with different framed routes in a set of overlapping framed routes as an active UE for delivering packets to connected devices in the device-side network. The processing circuitry is further configured forward the downlink packet to the connected device through the active UE.

[0015] A ninth aspect of the disclosure comprises a computer program for a UPF or other network node in a wireless communication system. The computer program comprises executable instructions that, when executed by processing circuitry in the network node, causes the network node to perform the method according to the first aspect.

[0016] A fifth aspect of the disclosure comprises a carrier containing a computer program according to the ninth aspect. The carrier is one of an electronic signal, optical signal, radio signal, or a non-transitory computer readable storage medium.BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 illustrates a wireless communication network implementing framed routing.

[0018] Figure 2 illustrates a wireless communication network implementing framed routing with dual connectivity via multiple user equipment (UEs).

[0019] Figure 3 illustrates packet processing by the UPF.

[0020] Figure 4 is a signal flow diagram illustrating a procedure to establish overlapping framed routes for multiple UEs.

[0021] Figure 5 illustrates a method implemented by a control plane network node for establishing overlapping framed routes for multiple UEs.

[0022] Figure 6 illustrates a method implemented by a user plane function for establishing overlapping framed routes for multiple UEs.

[0023] Figure 7 illustrates a control plane network node supporting overlapping framed routes for multiple UEs.

[0024] Figure 8 illustrates a user plane network node supporting overlapping framed routes for multiple UEs.

[0025] Figure 9 illustrates network node configured to implement overlapping framed routes for multiple UEs.DETAILED DESCRIPTION

[0026] Referring now to the drawings, an exemplary embodiment of the present disclosure will be described in the context of a 5GS network. Those skilled in the art will appreciate, however, that the techniques for using overlapping framed routes are more generally applicable to any type of network that supports framed routes.

[0027] Figure 1 illustrates an example of framed routing in a 5GS network 10. The 5GS network 10 comprises a 5G core network (5GC) 12, a 5G radio access network (RAN) 30, and a user equipment UE 40. The UE 40 provides connection to the 5GS 10 for a device-side network 50 using framed routes. The device-side network 50 comprises a router 52 in communication with the UE 40 and multiple host devices 54, also referred to herein as connected devices, that connect to the 5GS 10 via the UE 40. Figure 1 shows an example where the router 52 is colocated with the UE 40, but there may be other topologies as well.

[0028] The 5GC 12 comprises a collection of network functions (NFs) that provide connection to external data networks 70, such as the Internet and Internet Protocol (IP) Multimedia Subsystem (IMS). Two of the main functions of the 5GC 12 are to establish sessions for connected UEs 40 and to forward data between the connected UEs 40 and external data networks 70. The services of the 5GC 12 are provided by a group of network functions including a User Plane Function (UPF) 14, an Access and Mobility Management Function (AMF) 16, a Session Management Function (SMF) 18, a Policy Control Function (PCF) 20, and a Unified Data Management (UDM)function 22. Those skilled in the art will appreciate that the 5GC 12 may include additional network functions not shown in Figure 1 that are not material to the present disclosure. Further, figure 1 illustrates a point-to-point interface between the network functions. Those skilled in the art will appreciate that a service-based architecture can also be used where network functions communicate using a service-based interface (SBI).

[0029] The RAN 30 comprises one or more access nodes, which are also referred to as 5G NodeBs (gNBs) or base stations. The access nodes serve as access points for the 5GC 12 enabling the UEs 40 to connect to the 5GC 12.

[0030] The UE 40 may comprise any type of wireless device communicating with a RAN node (e.g. base station) and / or with another UE 40 in a wireless communication system. Examples of UEs 40 include cellular telephones, smart phones, tablets, notebooks, laptop computers, laptop mounted equipment (LME), vehicle-to-vehicle (V2V) communication devices, vehicle-to- everything (V2X) communication devices, machine type communication (MTC) devices, Machine- to-machine M2M communication devices, etc.

[0031] The 5G standards provide support for framed routing. See, e.g., 3GPP Technical Standard (TS) 23.501, clause 5.6.14. Framed routes provide a way for network operators to configure a range of IP addresses that are reachable at a given PDU session. The configuration is static and does not change for the lifetime of the PDU session. The configuration can be based on subscription information from the UDM 22, or from the AAA server. Based on the configuration in the UDM 22 or the AAA server, SMF 18 sets up PDRs (Packet Detection Rules) that map the downlink traffic for the given address range to a PDU session. This mapping allows traffic to be forwarded to connected devices 54 in the device-side network 50.

[0032] The current 3GPP solution for framed routing does not enable a connected device 54 in the device-side network 50 to be connected to the 5GS 10 via multiple UEs 40 simultaneously. Enabling multiple connections to the 5GS 10 for the device-side network could provideredundancy in case one of the paths (radio links between the UE 40 and the network) fails. With multiple connections to the 5GS 10, the connection to the 5GS can still be maintained even if the radio link to one of the UEs fails.

[0033] One aspect of the disclosure provides techniques to support overlapping framed routes so that connected devices 54 in a device-side network 50 can be reached via two or more different UEs 40. An example of a device side network 50 with multiple connections is shown in Figure 2. Each UE (UE1 and UE2) 40 providing connection to the 5GS 10 is configured with a framed route. In this example, the router 52 in the device-side network 50 connects to two UEs 40. Those skilled in the art will appreciate that other network topologies are also possible. For example, the device-side network may comprise two routers 52 providing connection to respective UEs 40.

[0034] The address ranges associated with the framed routes for the UEs 40 providing connection for the device-side network 50 either partially or fully overlap, so that connected devices 54 in the device-side network 50 can be reached via a path going through any one of multiple UEs 40. The framed routes with overlapping address ranges are referred to herein as overlapping framed routes. The overlapping framed routes configured for the UEs 40 providing connection to the 5GS 10 are associated with different PDU sessions.

[0035] To enable use of overlapping framed routes, a new parameter referred to herein as administrative distance is introduced, based on which SMF 18 determines precedence values of PDRs for the overlapping framed routes. Based on the precedence values of the overlapping framed routes, the UPF 14 maps the downlink traffic for the connected devices to one of the PDU sessions for one of the UEs 40. The basic idea is to have an active path and, if there is a failure in the active path, switch to an alternate path so that the connected devices 54 remain connected.

[0036] The PDRs determined by SMF 18 determine how downlink packets arriving at the UPF 14 are processed. A PDR contains information required to classify a packet arriving at a user plane, UP, function, e.g. a TDF-U, a PGW-U or a SGW-U, exemplified by UPF 14 in Fig. 2. There will be at least one PDR for both the uplink and the downlink. The PDR will contain various amounts of information depending upon the user function type. This will include a unique session and rule identity and also packet detection information such as source information, service data flow filter and application identity.

[0037] The mapping between IP packet and QoS Pipe for downlink packet is done by UPF 14 (i.e. in the Core Network). Within the UPF 14 is a special algorithm for this mapping which is called PDR (Packet Detection Rule). For each IP packet, PDR checks the information of the packet defined in the packet filter configuration (Source and Destination IP address and port, Protocol ID, Type of Service etc defined in 38.501-5.7.6.2, 5.7.6.3) and redirect the packet to a specific QoS Flow. The PDR is provided to UPF 14 by SMF 18 which interacts with PCF 20.

[0038] Figure 3 illustrates packet processing by the UPF 14. Each PDR contains Packet Detection Information (e.g., filters) that instruct the UPF 14 how to detect and classify downlink traffic. When a downlink packet arrives at the UPF 14, the UPF 14 determines a PFCP session with a matching PDR. The PFCP session may include multiple PDRs that match the incoming packet. After the PFCP session is determined, the UPF 14 determines the PDR within the PFCP session with the highest precedence value matching the incoming downlink packet. The selected PDR contains pointers to additional rules including QoS Enforcement Rules (QERs), Usage Reporting Rules (URRs), Forwarding Action Rules (FARs) and Buffering Action Rules (BARs). A match to a PDR leads to these other rules that describe how the packet is processed and forwarded. The FAR in particular contains information for how a packet shall be forwarded by the UPF 14. Thus, the PDR with the most favorable (e.g., highest, lowest) PDR determines how the downlink packet is processed and forwarded.

[0039] In a typical implementation provided as an example, the same UPF 14 is selected for UEs40 associated with overlapping framed routes, as depicted in Fig. 2. At least two administrative distance values (ADVs) are associated with each framed route that is configured for a UE 40 or for a PDU session: one for the case where the UE 40 is reachable and one for the case where the UE 40 is not reachable. Some embodiments may employ more than two ADVs. For example, separate ADVs can be defined for reachable UEs depending on the Radio Resource Configuration (RRC) state, e.g., one for RRC_Connected state and one for RRCJdle state. The ADVs are stored by the UDM 22 (Fig. 2).

[0040] When the PDU session for a UE 40 is established, SMF 18 determines the precedence value for PDRs corresponding to the framed routes configured for the UE 40 based on the ADVs associated with the framed routes, and particularly the reachability state of the UE 40. SMF 18 updates the precedence values whenever the reachability state of the UE 40 changes. In this way, overlapping framed routes may be configured for multiple UEs 40 and the precedence values of the PDRs (derived from the administrative distance) determine which route is active. Different ADVs can be set depending on the state of the UE 40 so that the routing changes accordingly, e.g. in case a UE 40 becomes unreachable on one of the paths or its RRC state changes to RRCJdle, and changes again when the UE 40 becomes reachable once again resp. the RRC state changes back to RRC_Connected.

[0041] Selecting a single UPF 14 for the UEs 40 that have overlapping framed routes avoids the need to advertise route changes to the data network 70, so that the redundant PDU sessions can remain internal to the 5GS 10 and are not exposed on the N6 interface. In the simple case, the 5GS 10 may have a single UPF 14 that handles all user plane traffic. In most implementations, however, there will be multiple UPFs 14. There are a number of ways to ensure that UEs 40 with overlapping famed routes are assigned to the same UPF 14.

[0042] In one embodiment, a single SMF 18 or SMF set is used for the network. SMF 18 stores framed route information for existing PDU sessions and is configured to use the same UPF 14 when a new PDU session is established if there is another UE 40 with an overlapping framed route. That is, when SMF 18 selects the UPF 14 for a PDU session, it first checks the stored framed route information to determine whether there is another UE 40 configured with an overlapping framed route and, if so, selects the same UPF 14.

[0043] In another embodiment, SMF 18 uses a single designated UPF 14 for all UEs 40 in the network that have framed routes configured. The identity of the designated UPF 14 can be retrieved from the Domain Name System (DNS) or from a Network Repository Function (NRF) (not shown).

[0044] In another embodiment, framed route information could be a criterion for UPF selection. In this embodiment, each UPF 14 has an associated address range for framed routes, which may be pre-configured. When SMF 18 selects a UPF 14 for a PDU session associated with a framed route, SMF 18 selects the UPF 14 with the matching address range. With proper configuration, there should be just one UPF 14 where a given framed route address space fits. A default UPF 14 may be selected for framed routes where there is no matching UPF address space. The information for the UPF address range could be configured into the NRF or DNS or retrieved from the UPFs 14.

[0045] Instead of the framed routes themselves, UPF selection could be based on a classification of the UEs 40. For instance, the UEs 40 in a network can be classified into A, B and C classes. The network operator takes action to ensure that UEs 40 having overlapping address space are always classified into the same class. The class information for the UPFs 14 can be configured into the DNS or NRF, and the class information can be used as a criterion for UPF selection.

[0046] In some deployments, it may be possible to assign UEs 40 with overlapping framed routes to different UPFs 14. In one implementation, a central controller responsible for routing packets inthe network is notified in case one of the PDU sessions becomes reachable / unreachable, or in case a PDU session is established or released. Responsive to these changes, the central controller can take action to update the routing accordingly in the rest of the network (in both uplink and downlink direction), and use the relevant paths where the connected devices 54 are reachable. In other deployments, instead of a central controller, a distributed routing protocol may be used which is notified of the changes of the reachability state of a given session / port which then takes action accordingly.

[0047] In addition to selecting the UPF 14, SMF 18 needs to set the precedence values for the PDRs for with PDU sessions associated with overlapping framed routes. At least two ADVs are stored by the UDM 22 or AAA server each framed route in a set of overlapping framed routes: one for a reachable UE 40, and one for the case where the UE 40 is unreachable. In one embodiment, a smaller ADV corresponds to higher priority. Table 1 below shows an example of ADVs for a set of overlapping framed routes associated with UE A and UE B respectively.Table 1 : Example of ADVs For Overlapping Framed Routes

[0048] In this example, the ADVs are set so that in case one UE 40 is reachable and the other one is not, the reachable UE 40 would be selected. If the reachability state of the two UEs 40 are the same, then UE A is selected. The selection is performed in the UPF 14 as part of packet processing.

[0049] SMF 18 maps the ADVs to precedence values for the PDRs (Packet Detection Rules).SMF 18 has some flexibility in how to map the values into a range that it uses for other precedence values. The mapping should preserve the relative order of priorities determined based on the ADVs. It is also possible that the precedence values are identical to the ADVs.

[0050] In order to perform the mapping of ADVs to precedence values, SMF 18 maintains the reachability state of the UE 40 for a given PDU session. In one embodiment, SMF 18 subscribes to UE reachability state change notifications from AMF 16, as described in section 4.2.5.3 of 3GPP TS 23.502, clause 4.2.5.3 using the Namf_EventExposure service for the UE reachability status. A subscription to UE reachability status can be requested by SMF 18 for any UE 40 having a framed route with separate ADVs for reachable and unreachable states.

[0051] In some embodiments, it may be possible to have additional differentiation of the administrative distance for UEs 40 in a RRC_Connected state. For example, the network operator can define different ADVs for RRC_Connected and RRCJdle modes for a reachable UE40 in addition to the unreachable state. In this case, the ADV is updated according to notifications from SMF on UE connected-idle state changes.

[0052] Further parameters based on which the ADVs can be set are also conceivable, e.g. based on a quality, bandwidth or error rate of the (radio) connection of a UE 40 with the network, e.g. with RAN 30 and / or U PF 14.

[0053] Based on the ADVs, SMF 18 maps the ADVs corresponding to the current state of the UE 40 to a precedence value for the PDRs corresponding to the framed routes. SMF 18 updates the precedence value whenever the reachability state of the UE 40 changes. UPF 14 then applies the PDRs to downlink packets.

[0054] Figure 4 shows a simplified signal flow for setting and updating precedence values for overlapping framed routes. The UE 40 establishes a PDU session with SMF 18 (S1). As part of the PDU session establishment, the SMF selects the UPF 14 and retrieves framed route information from UDM 22 or AAA server (cf. Fig. 2) (S2). In this example, it is assumed that the framed routes for the PDU session are associated with at least two ADVs, e.g., for reachable and unreachable states respectively. The reachability state of UE 40 determines the reachability statefor all PDU sessions of that UE 40. SMF 18 maps the ADVs for the reachable state to a precedence value and sets up PDRs for the PDU session (S3).

[0055] Once the PDU session is established, SMF 18 subscribes with AMF 16 to receive notifications of changes to UE reachability state using the Namf_EventExposure service (S4). When the UE 40 becomes unreachable, AMF 16 sends an event notification to SMF 18 to notify the SMF 18 of the change in the reachability state of the UE 40 (S5). Responsive to the notification, SMF 18 updates the PDR precedence value based on the ADV for unreachable state (S6). The change in the precedence value for the PDR may affect the path selection by the UPF 14. If another UE 40 is reachable, the change in the PDR may cause the UPF 14 to select another reachable UE 40 as the active UE 40. Because a reachable UE 40 has a higher precedence than an unreachable UE 40, the solution routes traffic via the reachable UE 40 in the downlink direction thereby providing redundancy in case one of the UEs 40 become unreachable. When the first UE 40 with higher priority becomes reachable once again, AMF 16 sends another event notification to SMF 18 to notify SMF 18 that the UE 40 is now reachable (7). Responsive to the notification, SMF 18 updates the PDR precedence value based on the ADV for unreachable state (8). The change in the precedence value for the PDR may cause the UPF 14 to select switch back to the first UE 40 as the active UE 40.

[0056] When the precedence value for two PDRs are the same, a tie-breaker rule can be used by UPF 14 to select the active UE 40 and / or PDU session. For example, precedence can be given to the UE / PDU session with the lowest IP address, or with the lowest Subscription Permanent Identifier (SUPI). In some embodiments, UPF 14 may break the tie based on a value derived from identifiers related to the PDU sessions; or based on a randomized selection.

[0057] In cases where the same SMF 18 is used in the network, a tie-breaker may also be used in the SMF 18. For example, where the ADVs are the same for two UEs, SMF 18 can break thetie based on an identifier associated with the PDU sessions, and select the one which takes precedence. In this case, the SMF assigns a higher precedence value to the selected UE 40.

[0058] Optimizations

[0059] In some embodiments, UPF 14 reports errors to the SMF 18 using Packet Forwarding Control Protocol (PFCP) Session Report procedure when UPF 14 detects an error in the user plane (such as the GTP tunnel being unreachable). When the report indicates to the SMF 18 that the user plane is not in operation, SMF 18 updates the reachability state of UE 40 and, if needed, updates the PDR precedence value accordingly. When a new report indicates that the user plane is back in operation, SMF 18 can update the PDR precedence value again, if needed. In this way, the system can react to not only the air interface unreachability status, but also the user plane errors on the N3 interface, such as General Packet Radio Service (GPRS) Tunneling Protocol (GTP) errors.

[0060] In some embodiments, the timer for periodic registrations for UEs 40 having overlapping framed routes is reduced in order to shorten the time to detect a change in UE reachability state. SMF 18 may provide an indication to AMF 16 to reduce the period for periodic registrations when a UE 40 has framed routes with multiple administrative distance values.

[0061] In some embodiments, the inactivity timer used in the RAN 30 used for connected to idle transactions for UEs 40 with overlapping framed routes is increased. In one implementation, SMF 18 sends an indication to AMF 16 to increase the inactivity timer of the UE 40. By keeping the UE 40 in connected state for a longer period, RAN 30 can quickly detect unreachability state and notify AMF 16 when the UE 40 is detected to be unreachable. In connected mode, the updates in the routing could be made faster in the same way.

[0062] In some embodiments, when the precedence for two PDRs in UPF 14 are the same, UPF 14 uses round-robin selection when forwarding downlink traffic. This approach is useful when both UEs 40 are unreachable. UPF 14 can try each UE 40 one by one to determine whetherreachability has been restored. As another alternative, if the same SMF 18 controls the two UEs 40 with overlapping framed routes, the SMF 18 can increase or decrease the precedence values, e.g., by a constant (e.g., one) after each paging attempt, so that the two PDRs would in turn have different precedence values, one smaller than the other, changed in a round-robin fashion.

[0063] When the two or more PDU sessions for two or more UEs 40 are handled by the same SMF 18, SMF 18 can be configured to notify each UE 40 of the reachability status of the PDU session of the other UEs 40. For example, if the PDU session for UE1 becomes unreachable, SMF 18 sends a notification to UE2 that the PDU session for UE1 has become unreachable. For this, the identity of the given PDU session is provided, for example, by using the assigned IP address, or the combination of SUPI and PDU session ID. SMF 18 may also provide an indication when the PDU session becomes reachable again. Additionally, SMF 18 can be configured to indicate to a UE 40 when a PDU session is released for another UE 40. The information can help UE 40 detect that the interface corresponding to the PDU session is down so that uplink traffic can be re-routed by the UE 40 to the other PDU session. In the case where the SMFs 18 for the PDU sessions are different, the SMF 18 can send the notification to the peer SMF 18, which in turn can notify the UE 40. In this case, the SMF 18 may need to identify the SMF 18 for the UE 40 to be notified, which can be realized by querying all other SMFs 18 in the network whether a UE 40 with an overlapping framed route (or with the same UE identifier, if there is such an ID) can be found.

[0064] In some embodiments, the change of another UE 40 from unreachable to reachable status may be detected by the UE 40.

[0065] In some embodiments, the framed route information and ADVs can be configured externally rather than being stored in the UDM 22 or AAA server. In one embodiment, a central configuration server (such as an Software Defined Network (SDN) controller), signals theconfiguration to a Network Exposure Function (NEF) (not shown). The NEF can store the framed route information in the UDR or forward it to the SMF 18.

[0066] As another alternative, the UEs 40 with overlapping framed routes can provide information to the system regarding the framed routes and ADVs. When a UE 40 or connected device 54 is authenticated and authorized, it could provide the framed route information and ADVs for specific UEs 40. The network operator can control which of the UEs 40 or connected devices 54 are authorized to provide such information. The framed route information provided by the UEs 40 or connected devices 54 could be stored in the UDM 22 or provided to the SMF 18.

[0067] Besides the actual framed routes and ADVs, the configuration server (or UE 40 or connected device 54) could also provide explicit information about whether to apply the mechanism to allow multiple overlapping framed routes and whether to change the path depending on the reachability state of a given PDU session for a given UE 40.

[0068] For uplink traffic, the device side network can detect when a PDU session is currently unreachable, which corresponds to a link down event at the corresponding UE 40 or router 52. The link down event will cause the routing in the device side network to be updated, so that the PDU session with the reachable UE 40 is used in the uplink.

[0069] In scenarios where a single router 52 has two UEs 40 with the corresponding PDU sessions, the router 52 detects when the interface to the unreachable UE is down, and therefore uses the other UE 40 to send uplink data. In other topologies, where a routing protocol may be in operation in the device side network, the PDU session with unreachable state leads to a link down event, which triggers corresponding changes in the routing protocol state, so that the PDU session for the reachable UE 40 is used for uplink traffic.

[0070] It should be noted that the routing in uplink and downlink directions can be different (i.e. , asymmetric routing), where one UE 40 is used in the uplink and another is used in the downlink.In the UPF 14, the uplink traffic could be allowed through a PDU session even if the other PDU session is being used in the downlink.

[0071] When a PDU session becomes unreachable, UPF 14 may stop advertising the corresponding framed routes on the N6 interface. This may be a valid action also when there is only a single PDU session for the given framed routes. By not advertising the framed routes, it possible to use other alternate paths, e.g., non-3GPP accesses.

[0072] In case two (or multiple) PDU sessions exist with overlapping framed routes, UPF 14 stops advertising the given framed routes when all the PDU sessions become unreachable to enable the use of alternate (e.g., non-3GPP) paths. In this case, the UPF 14 needs to check for overlapping framed routes. When a PDU session becomes reachable again, the corresponding PDU session can again be advertised on the N6 interface.

[0073] This advertising of PDU sessions for overlapping framed routes can be further supported by the following mechanisms.• An explicit indication can be sent to the UPF 14 about the reachability state for the given session (i.e. , UE 40 reachable or unreachable). Without such indication, the reachability can be determined from the precedence value for the PDR.• Alternatively, an explicit indication can be sent to UPF 14 whether to advertise the given framed route on N6 interface. With this approach, the SMF 18 could explicitly control the advertising of framed routes on N6 interface and disable advertising when the framed route is currently not reachable. As another alternative, instead of stopping the advertisement of a framed route when the UEs 40 are not reachable, the framed route could be advertised with a poor metric (higher cost).• Some embodiments may employ an identifier for the framed routes. Using an identifier for the framed routes, the UPF 14 can more easily detect the framed routes that are the same or overlap, without having to parse them. The identifier could be configured together with the framedroutes into the UDM 22 or AAA server, or could be generated by the SMF 18 using a hash of the framed route, or could be pre-configured into the SMF 18. Using the framed route identifier, the UPF 14 can more easily identify the PDU sessions with overlapping framed routes so that it can detect when all of them are in unreachable state (and hence it should stop advertising the framed routes on N6 interface.)• Some embodiments may employ a list of the session identifiers with overlapping framed routes. In place of or in addition to identifiers for the framed routes, a list of the session identifiers can be provided for the UPF 14 to identify the overlapping framed routes. This option is relevant for cases when a single SMF 18 is used that can identify the overlapping framed routes. If the reachability state of UE 40 changes too frequently (above a threshold), the UPF 14 may not react to the changes and continue to advertise the framed routes even while the UEs 40 are not reachable, until the frequency of the changes drops below the threshold.

[0074] Following expiration of a timeout period after a UE 40 becomes unreachable, the SMF 18 may optionally release the corresponding PDU session. The release can be synchronized with the UE 40 when the UE 40 comes reachable again. In some scenarios, a PDU session may be released after the AMF 16 detaches the UE 40 that is not reachable for a given period of time.

[0075] When a PDU session is released, the corresponding framed route is no longer advertised on the N6 interface. In case multiple PDU sessions with overlapping framed routes are used, the UPF14 should stop advertising the framed routes only when all of the PDU sessions have been released or became unreachable.

[0076] The release of a PDU session may help in deployments when the advertising of the framed route on N6 is only stopped at the release of the PDU session. The release of a PDU session may aid the UE 40 in detecting that the corresponding link is down. On the other hand, if a PDU session is released, the UE 40 would need to re-establish the PDU session to be able touse it once more. Thus, it may be more efficient in some cases to keep the PDU session while the UE 40 is unreachable.

[0077] In some deployments, such as in the case of Deterministic Networks (DetNet), a central controller (e.g., SDN controller) that has a knowledge of the network topology can be used. In such scenarios, the release of the PDU session results in the release of a port of the logical 5GS router, and a notification message is provided to the central controller. This allows the central controller to reconfigure the network, e.g., to modify the uplink routing tables and re-route the uplink traffic through the existing PDU session. Also routing modification in the downlink may be possible in case of deployments where the UPF 14 is separate for the two paths.

[0078] In some deployments, it may be possible that not only the release of a PDU session, but also the state changes between reachable and unreachable state for the PDU session may be exposed. For the unreachable session, the port may be considered temporarily down. In this way, the central controller can update the routing in the network (device side or network side) accordingly.

[0079] In some embodiments, periodic user plane probing packets on the user plane paths can be used to check the state of a given path, i.e. , whether it is up or down. When probing is employed, probing packets are sent in both directions by two nodes or hosts. Detection of the probe packets by the UPF 14 indicates that the user plane path is operational, otherwise it can be considered being unreachable.

[0080] In some embodiments, probing could be set up between two endpoints, which may be outside the 3GPP network. The 3GPP network can become aware of the probing by explicit a priori configuration, or by signaling indication. The configuration could be stored by the UDM 22 or AAA server and downloaded to the SMF 18. The signaling could take place, for example, via the NEF, and be provided to the SMF 18. When the SMF 18 is aware of probing packets, it can establish filtering rules in UPF 14 to report when the probing packets are detected. Based on thisinformation, SMF18 can declare a path to be reachable or not reachable, and update the precedence values for the PDRs accordingly.

[0081] UPF 14 may also detect Internet Control Message Protocol (ICMP) host unreachable packets on a path, which can be taken as an indication that a given path is not considered operational if the host address falls within the framed routes address range.

[0082] In some embodiments, two (or more) downlink paths towards the same destination can be used where multiple paths are operational and load balancing between the paths can be applied. When UPF 14 has two PDRs to the same destination with the same precedence, UPF 14 may apply load balancing. Load balancing can be achieved by detecting the traffic flows and making separate decisions which path to use. Some flows may take one path, while other flows take another path. The flows may be identified, based on a hash value of the header fields. SMF 18 may use an explicit indication to UPF 14 to apply load balancing. It may be possible to apply load balancing in the uplink as well, even though that may be outside the scope of the 3GPP network.The round robin scheme mentioned above can also be an example of load balancing.

[0083] The techniques herein described can be triggered when SMF 18 detects two (or more) ADVs corresponding to framed routes. Alternatively, an explicit indication can be configured into the UDR 22, AAA server or into the SMF 18 to use the mechanism and change the precedence of the PDRs based on the reachability status. Some aspects of the solution may be triggered by explicit indication or configuration in the UDR 22, AAA server or in SMF 18, e.g., whether to select the same UPF 14, what type of tie-breaker rule to apply, whether to notify an external controller about state changes, and so on.

[0084] Figure 5 illustrates an exemplary method 100 implemented by SMF 18 in a wireless communication network supporting overlapping framed routes though two or more user equipments (UEs) to the same device-side network. The SMF 18 obtains at least two ADVs associated with a framed route in a set of overlapping framed routes associated with differentUEs 40. Each ADV is associated with a different reachability state of a corresponding one of the UEs. The SMF 18 further configures, based on the ADVs for the framed routes and the reachability states of the corresponding UEs 40, a user plane of the wireless communication network to select a UE 40 associated with one of the framed routes in the set of overlapping framed routes as an active UE 40 for delivering packets to connected devices in the device-side network.

[0085] In some embodiments of method 100, a first ADV for the framed route is associated with a reachable state and a second ADV for each framed route is associated with an unreachable state.

[0086] In some embodiments of method 100, the first administrative distance value for the framed route determines a priority of the framed route in the set of overlapping framed routes when the corresponding UE 40 is in a reachable state.

[0087] In some embodiments of method 100, a first ADV for the framed route is associated with a connected state, a second ADV for the framed route is associated with an idle state, and a third administrative distance value for the framed route is associated with an unreachable state.

[0088] In some embodiments of method 100, configuring the user plane to select a UE 40 as the active UE 40 comprises configuring a User Plane Function (UPF) with Packet Detection Rules (PDR) for two or more of the overlapping framed routes, wherein the PDR for each framed route includes a precedence value determined based on the ADS and the reachability state of the corresponding UE 40 indicating relative priorities of the framed routes depending on reachability state.

[0089] Some embodiments of method 100 further comprise, responsive to a change in reachability state of a first UE 40 associated with one of the framed routes in the set of overlapping framed routes, updating a PDR for each framed route affected by the change in reachability state of the first UE.

[0090] In some embodiments of method 100, the first UE 40 is the current active UE, the reachability state of the current active UE 40 changes from reachable to unreachable and thePDR for the current active UE 40 is updated such that another UE 40 is selected as a new active UE 40 to replace the current active UE.

[0091] In some embodiments of method 100, the first UE 40 is a current inactive UE 40, the reachability state of the current inactive UE 40 changes from unreachable to reachable, and the PDR for the current inactive UE 40 is updated such that the current inactive UE 40 replaces the current active UE 40 as a new active UE 40.

[0092] In some embodiments of method 100, the SMF 18 receives, from a second network node in the wireless communication network, an indication of the change in reachability state of the first UE 40. The second network node may comprise an AMF. The SMF may subscribe to receive UE 40 reachability state change notifications from the second network node, e.g. from AMF 16.

[0093] In some embodiments of method 100, the second network node comprises the UPF.

[0094] In some embodiments of method 100, the SMF 18 receives, from a UE 40 associated with one of the framed routes in the set of overlapping framed routes, an indication of the change in reachability state of the first UE.

[0095] Some embodiments of method 100 further comprise selecting a single UPF 14 for the UEs 40 associated with overlapping framed routes.

[0096] In some embodiments of method 100, selecting a single UPF 14 for the UEs 40 associated with overlapping framed routes comprises receiving a request to establish a PDU session from a first UE, obtaining framed route information for the first UE, selecting a UPF 14 for the first UE 40 depending on whether a first framed route associated with the first UE 40 overlaps a second frame route associated with a second UE.

[0097] In some embodiments of method 100, selecting a single UPF 14 for the UEs 40 associated with overlapping framed routes comprises receiving a request to establish a PDUsession from a first UE, obtaining framed route information for the first UE, and selecting a designated UPF for the first UE 40 depending on whether a framed route is configured for the firstUE 40.

[0098] In some embodiments of method 100, selecting a single UPF 14 for the UEs 40 associated with overlapping framed routes comprises receiving a request to establish a PDU session from a first UE, obtaining framed route information for the first UE 40 including an address range for a framed route, and selecting a designated UPF 14 for the first UE 40 depending on the address range for the framed route.

[0099] Some embodiments of method 100 further comprise providing an indication to a second network node to modify a periodic registration period for one of the UEs 40 associated with a framed route in the set of overlapping framed routes.

[0100] Some embodiments of method 100 further comprise providing an indication to a second network node to modify an inactivity timer for one of the UEs 40 associated with a framed route in the set of overlapping framed routes.

[0101] Some embodiments of method 100 further comprise sending, to a first UE 40 associated with a framed route in the set of overlapping framed routes, a notification indicating change in the reachability state of a second UE 40 associated with another framed route in the set of overlapping framed routes.

[0102] In some embodiments of method 100, the notification includes a session identifier of a PDU session for the second UE 40.

[0103] Figure 6 shows a method implemented by a UPF 14 in a wireless communication network supporting overlapping framed routes though two or more user equipment (UEs) to the same device-side network. The UPF 14 receives a downlink packet addressed to a connected device 54 in the device-side network 50. The UPF 14 further selects a UE 40 from among a set of UEs 40 associated with different framed routes in a set of overlapping framed routes as an active UE40 for delivering packets to connected devices in the device-side network 50. The UPF 14 forwards the downlink packet to the connected device through the active UE.

[0104] In some embodiments of method 200, selecting a UE 40 associated with a framed route in a set of overlapping framed routes as an active UE 40comprises receiving, from a session management node, a set of PDRs for the set of overlapping framed routes, each PDR including a precedence value for a corresponding one of the framed routes indicating a relative priority of the framed route, and selecting the active UE 40 based on the precedence values associated with the framed routes in the set of overlapping framed routes.

[0105] Some embodiments of method 200 further comprise sending an error report to the session management node responsive to detecting an error in the user plane that impacts the reachability state of a UE 40 associated with a framed route in the set of overlapping framed routes.

[0106] Some embodiments of method 200 further comprise discontinuing advertisement of a framed route when the UE 40 associated with the framed route is unreachable.

[0107] In some embodiments of method 200, discontinuing advertisement of a framed route comprises receiving an indication from the session management node that the UE 40 is unreachable, responsive to the indication, discontinuing advertisement of the framed route associated with the unreachable UE.

[0108] In some embodiments of method 200, discontinuing advertisement of a framed route comprises receiving signaling from the session management node requesting the UPF 14 to stop advertising a framed route, discontinuing advertisement of the framed route indicated by the signaling.

[0109] In some embodiments of method 200, the UPF discontinues advertising the framed route when all UEs 40 associated with framed routes in the set of overlapping framed routes are unreachable.

[0110] Figure 7 illustrates a control plane network node, particularly session management node, 300 supporting overlapping framed routes. Control plane network node (e.g., SMF 18) comprises an obtaining unit 310 and configuration unit 320. The units 310-320 comprise one or more microprocessors, hardware, firmware or combination thereof. Obtaining unit 310 is configured to obtain at least two ADVs associated with a framed route in a set of overlapping framed routes associated with different UEs 40. Each ADV is associated with a different reachability state of a corresponding one of the UEs. Configuration unit 320 configures, based on the ADVs for the framed routes and the reachability states of the corresponding UEs 40, a user plane of the wireless communication network to select a UE 40 associated with one of the framed routes in the set of overlapping framed routes as an active UE 40 for delivering packets to connected devices in the device-side network.

[0111] Figure 8 illustrates a user plane network node 400 (e.g. UPF 14) supporting overlapping framed routes. User plane network node comprises a receiving unit 410, a selection unit 420 and a forwarding unit 430. The units 410-430 comprise one or more microprocessors, hardware, firmware or combination thereof. Receiving unit 410 is configured to receive a downlink packet addressed to a connected device 54 in the device-side network 50. Selecting unit 420 is configured to select a UE 40 from among a set of UEs 40 associated with different framed routes in a set of overlapping framed routes as an active UE 40 for delivering packets to connected devices in the device-side network 50. Forwarding unit 430 is configured to forward the downlink packet to the connected device through the active UE 40.

[0112] Figure 9 illustrates the main functional components of another exemplary network node 500 that can be configured to perform any one of the methods shown in Figures 5 - 6. The network node 500 comprises communication circuitry 510, processing circuitry 520, and memory530.

[0113] The communication circuitry 510 comprises network interface circuitry for communicating with other core network nodes over a communication network, such as an Internet Protocol (IP) network.

[0114] Processing circuitry 520 controls the overall operation of the network node 500 and is configured to perform one or more of the methods 100 and 200 shown in Figures 5 and 6 respectively. The processing circuitry 520 may comprise one or more microprocessors, hardware, firmware, or a combination thereof. The processing circuitry can be configured by software to perform the methods 100 and 200 shown in Figures 5 and 6 respectively.

[0115] Memory 530 comprises both volatile and non-volatile memory for storing computer program code and data needed by the processing circuitry 520 for operation. Memory 530 may comprise any tangible, non-transitory computer-readable storage medium for storing data including electronic, magnetic, optical, electromagnetic, or semiconductor data storage. Memory 530 stores a computer program 540 comprising executable instructions that configure the processing circuitry 520 to implement one or more of the methods 100 and 200 shown in Figures 5 and 64 respectively. A computer program in this regard may comprise one or more code modules corresponding to the means or units described above. In general, computer program instructions and configuration information are stored in a non-volatile memory, such as a ROM, erasable programmable read only memory (EPROM) or flash memory. Temporary data generated during operation may be stored in a volatile memory, such as a random access memory (RAM). In some embodiments, computer program 540 for configuring the processing circuitry 520 as herein described may be stored in a removable memory, such as a portable compact disc, portable digital video disc, or other removable media. The computer program 540 may also be embodied in a carrier such as an electronic signal, optical signal, radio signal, or computer readable storage medium.

[0116] Those skilled in the art will also appreciate that embodiments herein further include corresponding computer programs. A computer program comprises instructions which, when executed on at least one processor of an apparatus, cause the apparatus to carry out any of the respective processing described above. A computer program in this regard may comprise one or more code modules corresponding to the means or units described above.

[0117] Embodiments further include a carrier containing such a computer program. This carrier may comprise one of an electronic signal, optical signal, radio signal, or computer readable storage medium.

[0118] In this regard, embodiments herein also include a computer program product stored on a non-transitory computer readable (storage or recording) medium and comprising instructions that, when executed by a processor of an apparatus, cause the apparatus to perform as described above.

[0119] Embodiments further include a computer program product comprising program code portions for performing the steps of any of the embodiments herein when the computer program product is executed by a computing device. This computer program product may be stored on a computer readable recording medium.

Claims

CLAIMS1. A method (100) implemented by a first control plane network node (18) in a wireless communication network (10) supporting overlapping framed routes though two or more user equipments, UEs, (40) to the same device-side network (50), the method comprising: obtaining at least two administrative distance values associated with a framed route in a set of overlapping framed routes belonging to different UEs (40), each administrative distance value being associated with a different reachability state of a corresponding one of the UEs (40); and configuring, based on the administrative distance values for the framed routes and the reachability states of the corresponding UEs, a user plane function, UPF, (14) of the wireless communication network to select a UE (40) associated with one of the framed routes in the set of overlapping framed routes as an active UE (40) for delivering packets to and / or receiving packets from connected devices in the device-side network (50).

2. The method (100) of claim 1, wherein a first administrative distance value for the framed route is associated with a reachable state and a second administrative distance value for each framed route is associated with an unreachable state.

3. The method (100) of claim 2, wherein the first administrative distance value for the framed route determines a priority of the framed route in the set of overlapping framed routes when the corresponding UE (40) is in a reachable state.

4. The method (100) of any one of claims 1 to 3, wherein a first administrative distance value for the framed route is associated with a connected state, a second administrative distance value for the framed route is associated with an idle state, and a third administrative distance value for the framed route is associated with an unreachable state.

5. The method (100) of any one of the preceding claims, wherein configuring the UPF to select a UE (40) as the active UE (40) comprises configuring the UPF (14) with Packet Detection Rules, PDRs, for two or more of the overlapping framed routes, wherein the PDR for each framed route includes a precedence value determined based on the administrative distance values and the reachability state of the corresponding UE (40) indicating relative priorities of the framed routes depending on reachability state.

6. The method (100) of claim 5, further comprising: responsive to a change in reachability state of a first UE (40) associated with one of the framed routes in the set of overlapping framed routes, updating a PDR for each framed route affected by the change in reachability state of the first UE.

7. The method (100) of claim 6, wherein: the first UE (40) is the current active UE; the reachability state of the current active UE (40) changes from reachable to unreachable; and the PDR for the current active UE (40) is updated such that another UE (40) is selected as a new active UE (40) to replace the current active UE.

8. The method (100) of claim 6, wherein: the first UE (40) is a current inactive UE; the reachability state of the current inactive UE (40) changes from unreachable to reachable; and the PDR for the current inactive UE (40) is updated such that the current inactive UE (40) replaces the current active UE (40) as a new active UE.

9. The method (100) of any one of claims 6 - 8, further comprising receiving, from a second network node in the wireless communication network, an indication of the change in reachability state of the first UE.

10. The method (100) of claim 9, wherein the second network node comprises a AMF.

11. The method (100) of claim 10, further comprising subscribing to receive UE (40) reachability state change notifications from the AMF.

12. The method (100) of claim 9, wherein the second network node comprises the UPF (14).

13. The method (100) of any one of claims 6 - 8, further comprising receiving, from a UE (40) associated with one of the framed routes in the set of overlapping framed routes, an indication of the change in reachability state of the first UE.

14. The method (100) of any one of claims 1 - 13, further comprising selecting a single UPF (14) for the UEs associated with overlapping framed routes.

15. The method (100) of clam 14, wherein selecting a single UPF (14) for the UEs associated with overlapping framed routes comprises: receiving a request to establish a PDU session from a first UE; obtaining framed route information for the first UE; selecting a UPF (14) for the first UE (40) depending on whether a first framed route associated with the first UE (40) overlaps a second frame route associated with a second UE.

16. The method (100) of clam 14, wherein selecting a single UPF (14) for the UEs associated with overlapping framed routes comprises: receiving a request to establish a PDU session from a first UE; obtaining framed route information for the first UE; selecting a designated UPF (14) for the first UE (40) depending on whether a framed route is configured for the first UE.

17. The method (100) of claim 14, wherein selecting a single UPF (14) for the UEs associated with overlapping framed routes comprises: receiving a request to establish a PDU session from a first UE; obtaining framed route information for the first UE (40) including an address range for a framed route; selecting a designated UPF (14) for the first UE (40) depending on the address range for the framed route.

18. The method (100) of any one of claims 1 - 17, further comprising: providing an indication to a second network node to modify a periodic registration period for one of the UEs associated with a framed route in the set of overlapping framed routes.

19. The method (100) of any one of claims 1 - 17, further comprising: providing an indication to a second network node to modify an inactivity timer for one of the UEs associated with a framed route in the set of overlapping framed routes.

20. The method (100) of any one of claims 1 - 19, further comprising: sending, to a first UE (40) associated with a framed route in the set of overlapping framed routes, a notification indicating change in the reachability state of a second UE (40) associated with another framed route in the set of overlapping framed routes.21 . The method (100) of claim, 20, wherein the notification includes a session identifier of a PDU session for the second UE.

22. A method (200) implemented by a user plane function, UPF, (14) in a wireless communication network supporting overlapping framed routes though two or more user equipments, UEs, (40) to the same device-side network, the method (200) comprising: receiving a downlink packet addressed to a connected device in the device-side network; selecting a UE (40) from among a set of UEs (40) associated with different framed routes in a set of overlapping framed routes as an active UE (40) for delivering packets to connected devices in the device-side network; and forwarding the downlink packet to the connected device through the active UE.

23. The method (200) of claim 22, wherein selecting a UE (40) associated with a framed route in a set of overlapping framed routes as an active UE (40) comprises: receiving, from a session management node, a set of PDRs for the set of overlapping framed routes, each PDR including a precedence value for a corresponding one of the framed routes indicating a relative priority of the framed route; selecting the active UE (40) based on the precedence values associated with the framed routes in the set of overlapping framed routes.

24. The method (200) of claim 22 or 23, further comprising: sending an error report to the session management node responsive to detecting an error in the user plane that impacts the reachability state of a UE (40) associated with a framed route in the set of overlapping framed routes.

25. The method (200) of any one of claims 22 - 24, further comprising: discontinuing advertisement of a framed route when the UE (40) associated with the framed route is unreachable.

26. The method (200) of claim 25, wherein discontinuing advertisement of a framed route comprises: receiving an indication from the session management node that the UE (40) is unreachable; responsive to the indication, discontinuing advertisement of the framed route associated with the unreachable UE.

26. The method (200) of claim 25, wherein discontinuing advertisement of a framed route comprises: receiving signaling from the session management node requesting the UPF to stop advertising a framed route; discontinuing advertisement of the framed route indicated by the signaling.

27. The method (200) of claim 25, wherein the UPF discontinued advertising the framed route when all UEs associated with framed routes in the set of overlapping framed routes are unreachable.

28. A control plane network node (18, 300, 500) supporting overlapping framed routes though two or more user equipment (UEs) to the same device-side network, the network node being configured to: obtain at least two administrative distance values with a framed route in a set of overlapping framed routes belonging to different UEs, each administrative distance value being associated with a different reachability state of a corresponding one of the UEs; and configure, based on the administrative distance values for the framed routes and the reachability states of the corresponding UEs, a user plane of the wireless communication network to select a UE (40) associated with one of the framed routes in the set of overlapping framed routes as an active UE (40) for delivering packets to connected devices in the device-side network.

29. The control plane network node (18, 300, 500) of claim 28, further configured to perform the method of any one of claims 2 - 21.

30. A control plane network node (18, 300, 500) supporting overlapping framed routes though two or more user equipment (UEs) to the same device-side network, the network node comprising: communication circuitry (310) configured for communication with one or more other network nodes; processing circuitry (320) operatively connected to the communication circuitry and configured to: obtain at least two administrative distance values with a framed route in a set of overlapping framed routes belonging to different UEs, each administrative distance value being associated with a different reachability state of a corresponding one of the UEs; and configure, based on the administrative distance values for the framed routes and the reachability states of the corresponding UEs, a user plane of the wireless communication network to select a UE (40) associated with one of the framed routes in the set of overlapping framed routes as an active UE (40) for delivering packets to connected devices in the device-side network.

31. The control plane network node (18, 300, 500) of claim 30, wherein the processing circuitry is further configured to perform the method of any one of claims 2 - 21 .

32. A computer program (340) comprising executable instructions that, when executed by a processing circuit in a control plane network node (18, 300, 500) in a wireless communication network, causes the control plane network node (18, 300, 500) to perform the method of any one of claims 1 - 21.

33. A user plane function, UPF, (14, 400, 500) in a wireless communication network supporting overlapping framed routes though two or more user equipments, UEs, (40) to the same device-side network, the UPF being configured to: receive a downlink packet addressed to a connected device in the device-side network; select a UE (40) from among a set of UEs associated with different framed routes in a set of overlapping framed routes as an active UE (40) for delivering packets to connected devices in the device-side network; and forward the downlink packet to the connected device through the active UE.

34. The UPF (14, 400, 500) of claim 33, wherein the user plane network node is further configured to perform the method of any one of claims 23 - 27.

35. A user plane function, UPF, (14, 400, 500) in a wireless communication network supporting overlapping framed routes though two or more user equipments, UEs, (40) to the same device-side network, the UPF comprising: communication circuitry (310) configured for communication with one or more other network nodes; processing circuitry (320) operatively connected to the communication circuitry and configured to: receive a downlink packet addressed to a connected device in the device-side network; select a UE (40) from among a set of UEs associated with different framed routes in a set of overlapping framed routes as an active UE (40) for delivering packets to connected devices in the device-side network; andforward the downlink packet to the connected device through the active UE.

36. The user plane function of claim 35, wherein the processing circuitry (320) is further configured to perform the method of any one of claims 23 - 27.

37. A computer program (340) comprising executable instructions that, when executed by a processing circuit in a user plane network node (14, 400, 500) in a wireless communication network, causes the user plane network node (14, 400, 500) to perform the method of any one of claims 22 - 27.

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