Internet protocol multimedia subsystem application server, network node and methods in a wireless communications network

Abstract

A method performed by an Internet Protocol Multimedia Subsystem, IMS, Application Server, AS, for improving terminating call session establishment in a wireless communication network is provided. The IMS AS sends (302), to a User Equipment, UE, a first Session Initiating Protocol, SIP, message for establishing a terminating call session in a first domain and a first Radio Access Technology, RAT. Upon expiry of a timer, the IMS AS sends (303), towards a network node, a second SIP message. The second SIP message indicates that redirection of the UE 121 is required. In response to receiving (304) a third SIP message indicating the UE redirection has been completed, the IMS AS sends (305) a fourth SIP message to the UE for establishing the terminating call session in the first domain and any one out of the first RAT or a second RAT.

Description

[0001] INTERNET PROTOCOL MULTIMEDIA SUBSYSTEM APPLICATION SERVER,

[0002] NETWORK NODE AND METHODS IN A WIRELESS COMMUNICATIONS NETWORK

[0003] TECHNICAL FIELD

[0004] Embodiments herein relate to an Internet Protocol Multimedia Subsystem (IMS) Application Server (AS), a network node and methods therein. In some aspects, they relate to a call session establishment a wireless communications network.

[0005] BACKGROUND

[0006] In a typical wireless communication network, wireless devices, also known as wireless communication devices, mobile stations, stations (STA) and / or User Equipment (UE), communicate via a Wide Area Network or a Local Area Network such as a Wi-Fi network or a cellular network comprising a Radio Access Network (RAN) part and a Core Network (CN) part. The RAN covers a geographical area which is divided into service areas or cell areas, which may also be referred to as a beam or a beam group, with each service area or cell area being served by a radio network node such as a radio access node e.g., a Wi-Fi access point, a Base Station (BS) or a radio base station (RBS), which in some networks may also be denoted, for example, a Base Station (BS), a NodeB, eNodeB (eNB), or gNodeB (gNB) as denoted in Fifth Generation (5G) telecommunications. A service area or cell area is a geographical area where radio coverage is provided by the radio network node. The radio network node communicates over an air interface operating on a radio frequency with the wireless devices within the range of the radio network node.

[0007] 3rd Generation Partnership Project (3GPP) is the standardization body for specifying the standards for the cellular system evolution, e.g., including 3G, 4G, 5G and the future evolutions. Specifications for Evolved Universal Terrestrial Radio Access (E- UTRA) and Evolved Packet System (EPS) have been completed within the 3GPP. In 4G also called a Fourth Generation (4G) network, EPS is core network and E-UTRA is radio access network. In 5G, 5GC is core network, NR is radio access network. As a continued network evolution, the new release of 3GPP specifies a 5G network also referred to as 5G New Radio (NR) and 5G Core (5GC).

[0008] Frequency bands for 5G NR are being separated into two different frequency ranges, Frequency Range 1 (FR1) and Frequency Range 2 (FR2). FR1 comprises sub-6 GHz frequency bands. Some of these bands are bands traditionally used by legacy standards but have been extended to cover potential new spectrum offerings from 410 MHz to 7125 MHz. FR2 comprises frequency bands from 24.25 GHz to 52.6 GHz. Bands in this millimeter wave range have shorter range but higher available bandwidth than bands in the FR1.

[0009] Multi-antenna techniques may significantly increase the data rates and reliability of a wireless communication system. For a wireless connection between a single user, such as UE, and a base station (BS), the performance is in particular improved if both the transmitter and the receiver are equipped with multiple antennas, which results in a Multiple-Input Multiple-Output (MIMO) communication channel. This may be referred to as Single-User (SU)-MIMO. In the scenario where MIMO techniques is used for the wireless connection between multiple users and the base station, MIMO enables the users to communicate with the base station simultaneously using the same time-frequency resources by spatially separating the users, which increases further the cell capacity. This may be referred to as Multi-User (MU)-MIMO. Note that MU-MIMO may benefit when each UE only has one antenna. The cell capacity can be increased linearly with respect to the number of antennas at the BS side. Due to that, more and more antennas are employed in BS. Such systems and / or related techniques are commonly referred to as massive MIMO.

[0010] In addition to faster peak Internet connection speeds, 5G planning aims at higher capacity than current 4G, allowing higher number of mobile broadband users per area unit, and allowing consumption of higher or unlimited data quantities in gigabyte per month and user. This would make it feasible for a large portion of the population to stream high-definition media many hours per day with their mobile devices, when out of reach of Wi-Fi hotspots. 5G research and development also aims at improved support of machine to machine communication, also known as the Internet of things, aiming at lower cost, lower battery consumption and lower latency than 4G equipment.

[0011] The voice solution for 5G System (5GS) needs to be tightly coupled to an existing 4G Voice over LTE (VoLTE) deployment to provide a seamless voice service across the whole network with good characteristics.

[0012] The 5GC with Evolved Packet Core (EPC) interworking architecture is outlined in Figure 1. Figure 1 depicts 5GC with EPC interworking - Voice and Short Message Service (SMS).

[0013] MME means Mobility Management Entity.

[0014] SGW means Serving Gateway. HSS / UDM / UDR means Home Subscriber Server / Unified Data Management / User Data Repository.

[0015] SMF means Session Management Function.

[0016] PCF means Policy Control Function.

[0017] UPF means User Plane Control Function.

[0018] AMF means Access and Mobility Function.

[0019] Most Packet Switched Domain wireless networks deployed at operators today, seamlessly support VoLTE and Voice over NR (VoNR).

[0020] An idle mobile phone will always connect to a cell in a domain that offers the best radio conditions at a certain time.

[0021] In poor NR radio conditions, during Mobile Voice calls establishment over NR, temporary degradation conditions may occur in the RAN transmission layer. This may either prevent the call setup request, e.g., Session Initiation Protocol (SIP) INVITE, to reach a mobile terminating UE in downlink (DL) or may prevent the response, e.g., SIP 183, to reach a gNB in uplink (UL) and further to reach the IMS network. Amongst the various error scenarios that may occur, the loss of SIP 183 in the UL is the most predominant since SIP messages sent in the UL direction are more prone to errors in poor radio condition due to limited UE transmission power. At the cell edge, in poor radio conditions, a SIP 183 response message, which has a size of approximately 2000 bytes and beyond, may be segmented by the RAN Radio Link Control (RLC) layer in over 100 segments.

[0022] After receiving the transmission failure notification from gNB, the UE goes to IDLE state and enters a cell selection procedure trying to find a suitable cell. There is a high likelihood however that the UE may end-up selecting the same cell since the cell selection is based on downlink signal strength measurements, which are not always a good predictor of the uplink. As result, any Transmission Control Protocol (TCP) / SIP over User Datagram Protocol (UDP) retransmission may not succeed, and the call handling procedure is considered as failed and will not resume.

[0023] SUMMARY

[0024] As part of developing embodiments herein a problem was identified by the inventor and will first be discussed. As mentioned above, after receiving the transmission failure notification from gNB, the UE goes to IDLE state and enters the cell selection procedure trying to find a suitable cell. There is a high likelihood however that the UE may end-up selecting the same cell since the cell selection is based on downlink signal strength measurements, which are not always a good predictor of the uplink. As result, any TCP / SIP over UDP retransmission may not succeed, and the call handling procedure is considered as failed and will not resume. In this case, it will be beneficial to retry the mobile terminating call setup and hence increase the chance to save the call and gather better Call Setup Success Ratio (CSSR).

[0025] With the introduction of VoNR, the lack of a mechanism that allows to retry a failure Mobile Terminating (MT) call upon conditions which results on call unreachable and / or no response, results in a degradation of VoNR call success rate KPI compared with VoLTE.

[0026] Currently, there is no solution to retry a failed VoNR MT call, upon unreachable and / or timeout condition. The existing solution, legacy Circuit Switch (CS) breakout, is not applicable to retry a failed MT VoNR call due to lack of support for seamless mobility between 5G and CS, e.g., 2G and 3G.

[0027] An object of embodiments herein is to improve the performance of the wireless communications network by providing a more efficient call handling mechanism.

[0028] According to an aspect of embodiments herein, the object is achieved by a method performed by an Internet Protocol Multimedia Subsystem, IMS, Application Server, AS, for improving terminating call session establishment in a wireless communication network.

[0029] The IMS AS sends, to a User Equipment, UE, a first Session Initiating Protocol, SIP, message for establishing a terminating call session in a first domain and a first Radio Access Technology, RAT.

[0030] Upon expiry of a timer, the IMS AS sends, towards a network node, a second SIP message. The second SIP message indicates that redirection of the UE 121 is required.

[0031] In response to receiving a third SIP message indicating the UE redirection has been completed, the IMS AS sends a fourth SIP message to the UE for establishing the terminating call session in the first domain and any one out of the first RAT or a second RAT.

[0032] According to another aspect of embodiments herein, the object is achieved by a method performed by a network node for improving terminating call session establishment in a wireless communication network. The network node is associated with a first Radia Access Technology, RAT.

[0033] The network node receives a redirection message indicating that redirection of a User Equipment, UE, is required.

[0034] The network node triggers a redirection of the UE.

[0035] The network node sends a redirection complete message towards an Internet Protocol Multimedia Subsystem, IMS, Application Server, AS, indicating that the redirection of the UE has been completed.

[0036] According to another aspect of embodiments herein, the object is achieved by an Internet Protocol Multimedia Subsystem, IMS, Application Server, AS, configured to improve terminating call session establishment in a wireless communication network.

[0037] The IMS AS is configured to send, to a User Equipment, UE, a first Session Initiating Protocol, SIP, message adapted to establish a terminating call session in a first domain and a first Radio Access Technology, RAT.

[0038] Upon expiry of a timer, the IMS AS is configured to send, towards a network node, a second SIP message. The second SIP message is adapted to indicate that redirection of the UE is required.

[0039] In response to a reception a third SIP message indicating the UE redirection has been completed, the IMS AS is configured to send a fourth SIP message to the UE to establish the terminating call session in the first domain and any one out of the first RAT or a second RAT.

[0040] According to another aspect of embodiments herein, the object is achieved by a network node configured to improve terminating call session establishment in a wireless communication network. The network node is configured to be associated with a first Radia Access Technology, RAT.

[0041] The network node is configured to receive a redirection message adapted to indicate that redirection of a User Equipment, UE, is required.

[0042] The network node 130 is configured to trigger a redirection of the UE 121.

[0043] The network node is configured to send a redirection complete message towards an Internet Protocol Multimedia Subsystem, IMS, Application Server, AS. The redirection complete message is adapted to indicate that the redirection of the UE (121) has been completed.

[0044] In this way, an improved terminating call session establishment is achieved. This since when the time expires, the IMS AS launches the procedure to redirect the UE and then establishes the terminating call session to UE using the same domain. Embodiments herein e.g., bring the advantages of achieving an improved terminating call session establishment by reattempting to establish a failed establishment procedure on the same domain, after the UE has been redirected, e.g., to a different RAT or a different frequency and / or cell in a current RAT.

[0045] BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Examples of embodiments herein are described in more detail with reference to attached drawings in which:

[0047] Figure 1 is a schematic block diagram according to prior art.

[0048] Figure 2 is a schematic block diagram illustrating embodiments of a wireless communications network.

[0049] Figure 3 is a flowchart depicting embodiments of a method in an IMS AS.

[0050] Figure 4 is a flowchart depicting embodiments of a method in a network node.

[0051] Figure 5 is a flowchart depicting examples of embodiments herein.

[0052] Figure 6 is a signaling diagram illustrating examples of embodiments herein.

[0053] Figure 7 is a schematic block diagram illustrating embodiments of an IMS AS.

[0054] Figure 8 is a schematic block diagram illustrating embodiments of a network node.

[0055] Figure 9 shows an example of a communication system QQ100 in accordance with some embodiments.

[0056] Figure 10 shows a UE QQ200 in accordance with some embodiments.

[0057] Figure 11 shows a network node QQ300 in accordance with some embodiments.

[0058] Figure 12 is a block diagram of a host QQ400, which may be an embodiment of the host QQ116 of Fig. 9, in accordance with various aspects described herein.

[0059] Figure 13 is a block diagram illustrating a virtualization environment QQ500 in which functions implemented by some embodiments may be virtualized.

[0060] Figure 14 shows a communication diagram of a host QQ602 communicating via a network node QQ604 with a UE QQ606 over a partially wireless connection in accordance with some embodiments.

[0061] DETAILED DESCRIPTION Embodiments herein relate to a wireless communications network and the determination of scheduling trigger rules.

[0062] As mentioned above, an object of embodiments herein is to improve the performance of the wireless communications network by providing a more efficient call handling mechanism.

[0063] Embodiments herein provide methods for enhance MT voice call establishment signaling flows by introducing a retry mechanism to reattempt to establish the call on another Packet Switch (PS) access, e.g., LTE access, when a VoNR mobile terminating call fails due to the unreachable condition, e.g., triggered by 5G NR transmission disturbances under poor radio conditions.

[0064] More specifically, in case of a failed attempt to establish a call towards a terminating UE camped on an NR cell, due to NR disturbances that prevent either the call setup request SIP INVITE from reaching the UE or the response SIP 183 from the UE to reach gNB and hence reaching IMS network.

[0065] Embodiments herein may e.g., provide any of the following mechanisms:

[0066] 1. An IMS AS OK? to propagate an error notification via 5GC towards a network node in NR, such as a gNB. The error notification is indicating call failure cause and the need for UE redirection.

[0067] 2. The network node in NR, such as a gNB, to trigger redirection of the UE, upon reception of notification UE redirection required indication.

[0068] 3. The IMS AS to reattempt MT call towards PS registered contact when PS / 5G timeout. Decision may be based on a Terminating Access Domain Selection (T- ADS) selection policy criteria.

[0069] Examples of embodiments herein may provide that a MT call reattempt will be established on e.g., LTE, such as a VoLTE call, VoNR if the UE has been redirected to a another NR frequency, or if the PS retry fails, then legacy CS retry may also be invoked as a third option if CS available and combined attach supported.

[0070] Embodiments herein may bring the advantage of an improved VoNR Call Setup Success Ratio by introducing a call setup reattempt mechanism and save calls that otherwise will ending up in failure due to not reachable condition caused by poor NR radio conditions. Embodiments herein may further bring the advantage reusing several state-of-the art 3GPP standard procedures, e.g., 5G to 4G Release with redirect specified in 3GPP TS 38.331 V17.4.0 and 3GPP TS 23.502 V18.4.0; IP CAN Type change notification indicating change of access, Fast return procedure to NR after call being released, specified in 3GPP TS 38.331 V17.4.0, 3GPP TS 23.502 V18.4.0 chapter 4, 3GPP TS 23.501 V18.4.0.

[0071] Embodiments herein may further bring the advantage of saving VoNR MT calls that were intended to be MT EPS Fallback (FB) calls because EPS fallback for voice is triggered based on Quality of Service (QoS) resource reservation during a voice call. This is normally performed based on SIP 183 SDP response when SIP Precondition signaling is used. The absence of SIP 183 in the IMS network will prevent the QoS resource reservation from being triggered and hence also prevent EPS FB procedure from being triggered.

[0072] Figure 2 is a schematic overview depicting a wireless communication network 100 wherein embodiments herein may be implemented. The wireless communication network 100 comprises one or more RANs, one or more IMS networks, e.g. an IMS network 105, and one or more CNs. The wireless communication network 100 may use a number of different technologies, such as Wi-Fi, Long Term Evolution (LTE), LTE- Advanced, 5G, New Radio (NR), 6G, Wideband Code Division Multiple Access (WCDMA), Global System for Mobile communications / enhanced Data rate for GSM Evolution (GSM / EDGE), or Ultra Mobile Broadband (UMB), just to mention a few possible implementations. Embodiments herein relate to recent technology trends that are of particular interest in a 5G context, however, embodiments are also applicable in further development of the existing wireless communication systems such as e.g. WCDMA and LTE.

[0073] An IMS AS 110 operates in the IMS network 105. The IMS network 105 is an architecture for delivering media content over an IP packet switched transport. The IMS AS 110 may e.g., comprise a Service Centralization and Continuity AS (SCC AS) or a Telephony Application Server (TAS).

[0074] A number of RAN nodes operate in the wireless communication network 100 such as e.g., the network node 130. The network node 130 provides radio coverage in a number of cells which may also be referred to as a beam or a beam group of beams.

[0075] The network node 130 may be any of an NG-RAN node, a transmission and reception point e.g. a base station, a radio access network node such as a Wireless Local Area Network (WLAN) access point or an Access Point Station (AP STA), an access controller, a base station, e.g. a radio base station such as a NodeB, an evolved Node B (eNB, eNode B), a gNB, a base transceiver station, a radio remote unit, an Access Point Base Station, a base station router, a transmission arrangement of a radio base station, a stand-alone access point or any other network unit capable of communicating with a UE, such as e.g., a UE 121, within the service area served by the network node 130 depending e.g. on the radio access technology and terminology used. The network node 130 may be referred to as a serving RAN node and communicates with UEs such as the UE 121 , with Downlink (DL) transmissions to the UE 121 , and in Uplink (UL) transmissions from the UE 121.

[0076] A number of UEs, such as e.g., the UE 121 , operate in the wireless communication network 100. The UE 121 may also be referred to as an loT device, a mobile station, a non-access point (non-AP), a STA, and / or a wireless terminal. It should be understood by the skilled in the art that “UE” is a non-limiting term which means any terminal, wireless communication terminal, user equipment, Machine Type Communication (MTC) device, Device to Device (D2D) terminal, a radio device in a vehicle, or node e.g., smart phone, laptop, mobile phone, sensor, relay, mobile tablets or even a small base station communicating within a cell.

[0077] Methods herein may be performed by the IMS AS 110. As an alternative, a Distributed Node (DN) and functionality, e.g. comprised in the cloud 190 as shown in Figure 2, may be used for performing or partly performing the methods herein.

[0078] A number of embodiments will now be described, some of which may be seen as alternatives, while some may be used in combination. The embodiments of a method will first be generally described in view of the IMS AS 110 together with Figure 3, then in view of the network node 130 together with Figure 4. This will be followed by a more detailed description.

[0079] A method according to embodiments herein will now be described from the view of the IMS AS 110, together with Figure 3. Figure 3 depicts example embodiments of a method performed by the IMS AS 110 for improving terminating call session establishment in the wireless communication network 100. The IMS AS 110 may e.g., comprise a TAS 110 or a SCC AS 110. The method comprises the following actions, which actions may be taken in any suitable order. Actions that are optional are presented in dashed boxes in Figure 3.

[0080] Action 301 In some embodiments, upon receiving an invite SIP message, the IMS AS 110 activates an access selection policy for a terminating call session to be established. The access selection policy is related to handling a failed call session establishment. The invite SIP message, also referred to as SIP INVITE message, is directed towards the UE 121 for establishing the terminating call session.

[0081] The access selection policy may indicate which domain, such as PS domain or CS domain, that should be used for reattempting to establish a failed call session establishment. E.g., the access selection policy may indicate that a first reattempt is to be attempted using the PS domain, such as by using a PS contact or identity associated with the UE 121. Further the access selection policy may indicate that a second reattempt is to be attempted using the CS domain, such as by using a CS contact or identity associated with the UE 121. The access selection policy may e.g., comprise a T-ADS selection policy.

[0082] Action 302

[0083] The IMS AS 110 sends a first SIP message to the UE 121. The first SIP message is a message for establishing a terminating call session in a first domain and a first RAT. The first message may, e.g., comprise a SIP INVITE message, such as the same SIP INVITE message received in Action 301 above. The first domain may comprise a PS domain and the first RAT may comprise an NR RAT. In other words, the IMS AS 110 may send the first SIP message to the UE 121 in order to establish the call session in the PS domain and using the NR RAT. The first SIP message may comprise a contact or identity for the UE 121 corresponding to the first domain. E.g., if the first domain is the PS domain, the contact or identity may comprise a PS contact or identity.

[0084] Action 303

[0085] Upon expiry of a timer, the IMS AS 110 sends a second SIP message towards a network node 130. The second SIP message indicates that redirection of the UE 121 is required. The timer may e.g., comprise a Not Reachable Timer. The second SIP message may comprise a SIP CANCEL message. The second SIP message may instruct the network node 130 to trigger a mobility and / or cell selection procedure for the UE 121. The timer may expire when no SIP 18x message has been received within a time period the timer is configured with. A SIP 18x message may e.g., comprise a SIP 180 Ringing message, a SIP 181 Call is being forwarded message, a SIP 182 Queued message or a SIP 183 session progress message. In some embodiments, the IMS AS 110 may determine that the call session establishment has failed when the timer expires. This may trigger the IMS AS 110 to send the second SIP message.

[0086] Action 304

[0087] The IMS AS 110 receives a third SIP message indicating that the UE 121 redirection has been completed. The indication may trigger the IMS AS 110 to reattempt the call session establishment.

[0088] The indication may further indicate the RAT type the UE 121 has been redirected to. E.g., if the UE 121 was camped on an NR RAT and has been redirected to an LTE RAT, the indication may indicate RAT type E-UTRAN. Alternatively, the UE 121 that was camping on an NR RAT has been redirected to a different cell and / or frequency in the NR RAT, in which case the RAT type may indicate NR. The RAT type may e.g., be indicated in a P-Access-Network-Info header. Both the NR RAT and the LTE RAT supports call session establishment in the PS domain, e.g., VoNR in the NR RAT and VoLTE in the LTE RAT.

[0089] In some embodiments, the access selection policy indicates a domain, such PS domain or CS domain, to establish the terminating call session on upon a failure to establish the terminating call session. E.g., the access selection policy may indicate a first reattempt to establish the call session should use the PS domain. This may trigger the IMS AS 110 to try to establish the terminating call session using a PS contact or identity of the UE 121. In other words, the access selection policy may indicate the domain for a reattempt or retry to establish the terminating call session.

[0090] In some embodiments, receiving the indication comprises the IMS AS 110 enforcing the access selection policy associated to the UE 121. Enforcing the access selection policy may comprise checking what domain, such as PS domain or CS domain, should be used for reattempting to establish a failed call session establishment. Enforcing the access selection policy may further comprise checking whether the RAT type the UE 121 has been redirected to, supports establishing the call session on the domain to be used according to the access selection policy. E.g., if the access selection policy indicates that the PS domain should be used, the IMS AS 110 may check whether the RAT type the UE 121 has been redirected to supports call establishment using the PS domain. When determined that the RAT type supports the indicated domain, the IMS AS 110 may be triggered to reattempt to establish the call session on the indicated domain. When determined that the RAT type does not support the indicated domain, the IMS AS 110 may check a next entry in the access selection policy and check in the domain indicated in said next entry is supported by the RAT type the UE 121 has been redirected to. When determined that no entries in the access selection policy indicates a domain supported by the RAT type the UE 121 has been redirected to, the IMS AS 121 may consider that the call establishment has failed.

[0091] Action 305

[0092] In response to receiving the third SIP message indicating that the UE 121 redirection has been completed, the IMS AS 110 sends a fourth SIP message to the UE 121 for establishing the terminating call session in the first domain and any one out of the first RAT or a second RAT. The fourth message may comprise a SIP INVITE message. The fourth message may comprise a contact or identity for the UE 121 corresponding to the first domain. E.g., if the first domain is the PS domain, the contact or identity may comprise a PS contact or identity, whether the call session is established in first RAT or the second RAT may depend on the RAT type the UE 121 has been redirected to. E.g., if UE 121 is camped on an NR RAT, being an example of the first RAT, and the UE 121 has been redirected to a different cell and / or frequency in the in the NR RAT, the call session may be established in the NR RAT, i.e. , first RAT. In another example, the UE 121 is camped on the NR RAT, being an example of the first RAT, and the UE has been redirected to an LTE RAT, being an example of the second RAT, then the call may be established in the second RAT. In both of these examples, the UE 121 is camped in an NR RAT, and after a failed call establishment attempt in the PS domain, the call is established in the PS domain, such as the first domain, after redirecting the UE 121 to a different RAT or a different cell and / or frequency in the same RAT. In other words, after redirection of the UE 121 triggered by a failed call session establishment, the IMS AS 110 reattempts to establish the call session in the PS domain. This increases the performance of the wireless communication network 100 by a more efficient call session handling that reduces the failed call rate.

[0093] A method according to embodiments herein will now be described from the view of the network node 130, together with Figure 4. Figure 4 depicts example embodiments of a method performed by the network node 130 for improving terminating call session establishment in the wireless communication network 100. The network node 130 is associated with the first RAT. The method comprises the following actions, which actions may be taken in any suitable order. Actions that are optional are presented in dashed boxes in Figure 4. Action 401

[0094] The network node 130 receives a redirection message indicating that redirection of the UE 121 is required. The redirection message may correspond to the second SIP message sent by the IMS AS 110, as described above.

[0095] In some embodiments, the redirection message originates from the IMS AS 110.

[0096] As mentioned above, the redirection message may correspond to the second SIP message sent by the IMS AS 110, as described above. The redirection message may, however, not be a SIP message when the network node 130 receives is. The redirection may have been converted by an intermediate node, e.g., in CN. The indication that the redirection of the UE 121 is required may e.g., be comprised in an Attribute Value Pait (AVP) comprised in the redirection message.

[0097] In some embodiments, the redirection message is received in response to a failed terminating call session establishment to the UE 121. The terminating call session establishment may be associated with the first domain, such as the PS domain. As mentioned above, the call session establishment may have failed because the IMS AS 110 did not receive a response to the first SIP message upon expiry of the timer. This may be due to the fact that the UE 121 did not receive the first SIP message, or that response to the first SIP message sent by the UE 121 , such as a SIP 18x message, did not reach the network node 130.

[0098] Action 402

[0099] The network node 130 triggers a redirection of the UE 121. The network node 130 may trigger the redirection in response to receiving the redirection message.

[0100] In some embodiments, the UE 121 is redirected from the first RAT to a second RAT or from a cell and / or frequency in the first RAT to a different cell and / or frequency in the first RAT.

[0101] The first RAT may e.g., comprise an NR RAT and the second RAT may e.g., comprise an LTE RAT. Both the NR RAT and the LTE RAT supports call session establishment in the PS domain, e.g., VoNR in the NR RAT and VoLTE in the LTE RAT.

[0102] In some embodiments, triggering the redirection of the UE 121 comprises instructing the UE 121 to perform the redirection. E.g., when redirecting the UE 121 from the NR RAT, being an example of the first RAT, to the LTE RAT, being an example of the second RAT, the network node 130 may e.g., instruct the UE 121 by sending a release message to the UE 121. The release message may comprise instructions for reconnecting the LTE RAT.

[0103] Action 403 The network node 130 sends a redirection complete message towards the IMS AS 110. The redirection complete message indicates that the redirection of the UE 121 has been completed. The redirection complete message may correspond to the third SIP message received by the IMS AS 110. By indicating that the redirection of the UE 121 has been completed, the network node 130 enables a reattempt at establishing the terminating call session. This increases the performance of the wireless communication network 100 by a more efficient call session handling that reduces the failed call rate.

[0104] In some embodiments, wherein the redirection complete message indicates a RAT type the UE 121 has been redirected to. E.g., if the UE 121 was camped on an NR RAT and has been redirected to an LTE RAT, the indication may indicate RAT type E-UTRAN. Alternatively, the UE 121 was camped on an NR RAT has been redirected to a different cell and / or frequency in the NR RAT, in which case the RAT type may indicate NR.

[0105] Embodiments mentioned above will now be further described and exemplified. The embodiments below are applicable to and may be combined with any suitable embodiment described above.

[0106] Upon call delivery failure to a PS contact or identity due to timeout, the examples of embodiments herein introduce a PS retry mechanism that may comprise any one or more out of the following steps S51-S55, as shown in Figure 5.

[0107] S51. T-ADS functionality in the IMS AS 110 may comprise a selection policy set, such as the access selection policy, to retry on PS when call delivery to a PS registered contact times out. The selection policy may e.g., be triggered for PS retry according to e.g., any one or more out of:

[0108] - The UE 121 is not reachable, e.g., no SIP 18x response has been received by the AS 130 when the timer, e.g., a Not Reachable Timer, expires.

[0109] - The IMS AS 110 has received a SIP message with a header, e.g., P-Access- Network-lnfo (PAN I) header, comprising a RAT type the UE 121 is redirected to.

[0110] When triggered, the IMS AS 110 may act according to e.g., any one or more out of:

[0111] - The IMS AS 110 may cancel the call attempt, such as the call establishment started by the first SIP message, in response the UE 121 not being reachable, e.g., no SIP 18x response has been received by the AS 110 when the timer, e.g., a Not Reachable Timer, expires. - The IMS AS 110 may retry a new call attempt, e.g., by sending the fourth SIP message, to the PS registered contact or identity, e.g., the UE 121 , upon the condition that no 18x message has been received.

[0112] 552. The UE redirection required indication may be propagated towards the network node 130, e.g., via a Proxy Call Session Control Function (P-CSCF) in the IMS network 105 and the CN, e.g., via a Policy Control Function (PCF).

[0113] 553. The network node 130 may, in response to the UE redirection required indication, take further action, such as trigger mobility.

[0114] 554. The IMS AS 110 may receive a SIP message, such as an out of the blue SIP Method MESSAGE, indicating the completion of the redirection. The SIP message may be received from e.g., the P-CSCF, and the RAT type the UE 121 is directed to may be indicated in a PANI header.

[0115] 555. The T-ADS selection policy set, such as the access selection policy, may be enforced. The IMS AS may retry to establish the call session in the PS domain, e.g., by sending a new SIP INVITE message, such as the fourth SIP message, to the UE 121 , using a PS registered contact associated with the UE 121, e.g., the PS identity of the UE 121.

[0116] Figure 6 shows a signaling diagram according to embodiments herein. More specifically, Figure 6 shows an enhanced MT call flow resulting in PS retry upon timeout which may comprise any one or more out of the following steps S601-S611. The starting point for the call flow is an incoming call to a UE, such as the UE 121, that is connected to a PS Domain, such as the first RAT. In the example below the UE 121 is registered in a 5G PS domain.

[0117] 5601. A terminating session setup request is received by the IMS AS 110. A T-ADS procedure results in delivering the call to a PS contact or identity, such as a PS contact or identity of the UE 121 , when the recent location PS radio access network supports IMS Voice over PS and RAT-Type=NR, e.g., as obtained on TADSinformation.

[0118] 5602. A call invite message, such as the first SIP message, is propagated through the network towards the UE 121.

[0119] S603a. In a first alternative, the call invite message does not reach UE 121 due to potential poor radio conditions.

[0120] S603b. In a second alternative, a response SIP 18x message does not reach a gNB, such as the network node 130, and hence does not reach IMS network 105. 5604. The IMS AS 110 determines that the UE 121 is not reachable when no 18x response received when the timer expires, such as a T-ADS not-reachable timer, e.g., a Not Rechable Timer. The lack of response may be caused by either failure in S53a or S43b.

[0121] 5605. The IMS AS 110 may send a SIP CANCEL message, such as the second SIP message, towards the network node 130. The SIP CANCEL message may comprise an additional reason text: “UE redirection required”, such as the indication that redirection of the UE 121 is required.

[0122] 5606. The “UE redirection required” notification in the SIP CANCEL may be parsed by the P-CSCF and propagated to the PCF in Rx / AAR or by N5 / Npcf_PolicyAuthorization_Create request. A new Rx Attribute Valu Pair (AVP) may be created to carry the “UE redirection required” towards the PCF in the AAR triggered upon reception of the SIP CANCEL message. The same procedure must be applicable for N5 interface. The P-CSCF may also subscribe for IP-CAN-type and RAT-Type notification if it is not already done upon initial SIP registration. This is standardized legacy functionality.

[0123] 5607. The PCF may parse the received “UE redirection required” notification in the AAR carried by new AVP. The same solution applies for N5 interface. The PCF may then propagate the “UE redirection required” towards the gNB, such as the network node 130.

[0124] 5608. The gNB, such as the network node 130, may trigger further actions upon reception of “UE redirection required”. For coverage and / or mobility reasons, a UE connected, e.g., in RRC CONNECTED state, to NR may be redirected to LTE in cases when the NR connection becomes bad, and a suitable target LTE cell exists. The UE 121 will then be released from NR and supplied with redirect information that makes it possible to control the UE’s 121 transition to the target system. The UE 121 may perform LTE cell selection and transmit a tracking area update on completion. Alternatively, the UE 121 may be redirected to different NR cell and / or frequency when a suitable NR target cell and / or frequency exists.

[0125] 5609. Upon NR to LTE, or NR to NR mobility redirect completion, the PCF may inform the IP-CAN-type, RAT-Type: E-UTRAN (or RAT-Type: NR) to the P-CSCF in Rx RAR.

[0126] 5610. The P-CSCF may parse the received RAT-Type: 3GPP E-UTRAN (or RAT- Type: 3GPP NR) into a PANI header in an out-of-the-blue SIP MESSAGE, such as the third SIP message, and send it the IMS AS 110.

[0127] 5611. The IMS as 110, e.g., by T-ADS selection policy set, such as the access selection policy, checks the received notification about RAT-Type changed to E-UTRAN (or NR) and sends a new call setup request, e.g., a SIP INVITE, such as the fourth SIP message, towards the same PS registered contact or identity of the terminating UE 121. This call attempt is established in LTE access or NR access depending on the RAT type in the received notification.

[0128] To perform the method actions above, the IMS AS 110 is configured to improve terminating call establishment in the wireless communications network 100. The IMS AS 110 may comprise an arrangement depicted in Figure 7.

[0129] The IMS AS 110 may comprise an input and output interface 700 configured to communicate with each other. The input and output interface 700 may comprise a receiver, e.g. wired and / or wireless, (not shown) and a transmitter, e.g. wired and / or wireless, (not shown).

[0130] The embodiments herein may be implemented through a respective processor or one or more processors, such as at least one processor 710 of a processing circuitry in the IMS AS 110 depicted in Figure 7, together with computer program code for performing the functions and actions of the embodiments herein. The program code mentioned above may also be provided as a computer program product, for instance in the form of a data carrier carrying computer program code for performing the embodiments herein when being loaded into the IMS AS 110. One such carrier may be in the form of a CD ROM disc. It is however feasible with other data carriers such as a memory stick. The computer program code may furthermore be provided as pure program code on a server and downloaded to the IMS AS 110.

[0131] The IMS AS 110 and / or processor 710 is configured to improve terminating call session establishment in the wireless communication network 100.

[0132] The IMS AS 110 and / or processor 710 is configured to send, to the UE 121, the first SIP message adapted to establish a terminating call session in a first domain and a first RAT.

[0133] Upon expiry of a timer, the IMS AS 110 and / or processor 710 is configured to send, towards a network node 130, a second SIP message. The second SIP message is adapted to indicate that redirection of the UE 121 is required.

[0134] In response to the reception the third SIP message indicating the UE 121 redirection has been completed, the IMS AS 110 and / or processor 710 is configured to send the fourth SIP message to the UE 121 to establish the terminating call session in the first domain and any one out of the first RAT or a second RAT. In some embodiments, the second message is adapted to comprise a SIP CANCEL message.

[0135] In some embodiments, the IMS AS 110 and / or processor 710 is configured to receive the indication by enforcing an access selection policy associated to the UE 121.

[0136] In some embodiments, upon reception of a SIP INVITE message, the IMS AS 110 and / or processor 710 is configured to activate the access selection policy for the terminating call session to be established. The access selection policy is adapted to be related to handle a failed call session establishment.

[0137] In some embodiments, the call session handling policy is adapted to indicate a domain to establish the terminating call session on upon a failure to establish the terminating call session.

[0138] In some embodiments, the third SIP message is further adapted to indicate a RAT type the UE 121 has been redirected to.

[0139] In some embodiments, the first domain comprises a PS domain.

[0140] The IMS AS 110 may further comprise respective a memory 720 comprising one or more memory units. The memory 720 comprises instructions executable by the processor 710 in the IMS AS 110.

[0141] The memory 720 is arranged to be used to store instructions, data, configurations, identifiers, indications, notifications, resources, sessions, policies, RAT types, domains, and applications to perform the methods herein when being executed in the IMS AS 110.

[0142] In some embodiments, a computer program 730 comprises instructions, which when executed by the at least one processor 710, cause the at least one processor 710 of the IMS AS 110 to perform the actions above.

[0143] In some embodiments, a respective carrier 740 comprises the respective computer program 730, wherein the carrier 740 is one of an electronic signal, an optical signal, an electromagnetic signal, a magnetic signal, an electric signal, a radio signal, a microwave signal, or a computer-readable storage medium.

[0144] Thus, embodiments herein may disclose the IMS AS 110 configured to improve terminating call session establishment in the wireless communications network 100. The IMS AS 110 comprises the processor 710 and the memory 720, said memory 720 comprising instructions executable by said processor 710 whereby said IMS AS 110 is operative to perform any of the methods herein.

[0145] As will be readily understood by those familiar with communications design, that functions means or modules may be implemented using digital logic and / or one or more microcontrollers, microprocessors, or other digital hardware. In some embodiments, several or all of the various functions may be implemented together, such as in a single application-specific integrated circuit (ASIC), or in two or more separate devices with appropriate hardware and / or software interfaces between them. Several of the functions may be implemented on a processor shared with other functional components of a radio network node, for example.

[0146] Alternatively, several of the functional elements of the processing means discussed may be provided through the use of dedicated hardware, while others are provided with hardware for executing software, in association with the appropriate software or firmware. Thus, the term “processor” or “controller” as used herein does not exclusively refer to hardware capable of executing software and may implicitly include, without limitation, digital signal processor (DSP) hardware, read-only memory (ROM) for storing software, random-access memory for storing software and / or program or application data, and nonvolatile memory. Other hardware, conventional and / or custom, may also be included. Designers of communications receivers will appreciate the cost, performance, and maintenance trade-offs inherent in these design choices.

[0147] Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include digital signal processors (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as read-only memory (ROM), random-access memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and / or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according one or more embodiments of the present disclosure.

[0148] To perform the method actions above, the network node 130 is configured to improve terminating call establishment in the wireless communications network 100. The network node 130 is configured to be associated with a first RAT. The network node 130 may comprise an arrangement depicted in Figure 8. The network node 130 may comprise an input and output interface 800 configured to communicate with each other. The input and output interface 800 may comprise a receiver, e.g. wired and / or wireless, (not shown) and a transmitter, e.g. wired and / or wireless, (not shown).

[0149] The embodiments herein may be implemented through a respective processor or one or more processors, such as at least one processor 810 of a processing circuitry in the network node 130 depicted in Figure 8, together with computer program code for performing the functions and actions of the embodiments herein. The program code mentioned above may also be provided as a computer program product, for instance in the form of a data carrier carrying computer program code for performing the embodiments herein when being loaded into the network node 130. One such carrier may be in the form of a CD ROM disc. It is however feasible with other data carriers such as a memory stick. The computer program code may furthermore be provided as pure program code on a server and downloaded to the network node 130.

[0150] The network node 130 and / or processor 810 is configured to improve terminating call session establishment in the wireless communication network 100. The network node 130 is configured to be associated with the RAT.

[0151] The network node 130 and / or processor 810 is configured receive a redirection message adapted to indicate that redirection of the UE 121 is required.

[0152] The network node 130 and / or processor 810 is configured to trigger a redirection of the UE 121.

[0153] The network node 130 and / or processor 810 is configured send a redirection complete message towards the IMS AS 110. The redirection complete message is adapted to indicate that the redirection of the UE 121 has been completed.

[0154] In some embodiments, the redirection message is adapted to originate from the IMS AS 110.

[0155] In some embodiments, the network node 130 and / or processor 810 is configured to receive the redirection message in response to a failed terminating call session establishment to the UE 121.

[0156] In some embodiments, the redirection complete message is adapted to indicate a RAT type the UE 121 has been redirected to.

[0157] In some embodiments, the UE 121 is adapted to be redirected from the first RAT to a second RAT or from a cell and / or frequency in the first RAT to a different cell and / or frequency in the first RAT. In some embodiments, the network node 130 and / or processor 810 is configured trigger the redirection of the UE 121 by instructing the UE 121 to perform the redirection.

[0158] The network node 130 may further comprise respective a memory 820 comprising one or more memory units. The memory 820 comprises instructions executable by the processor 810 in the network node 130.

[0159] The memory 820 is arranged to be used to store instructions, data, configurations, identifiers, indications, notifications, resources, sessions, policies, RAT types, domains, and applications to perform the methods herein when being executed in the network node 130.

[0160] In some embodiments, a computer program 830 comprises instructions, which when executed by the at least one processor 810, cause the at least one processor 810 of the network node 130 to perform the actions above.

[0161] In some embodiments, a respective carrier 840 comprises the respective computer program 830, wherein the carrier 840 is one of an electronic signal, an optical signal, an electromagnetic signal, a magnetic signal, an electric signal, a radio signal, a microwave signal, or a computer-readable storage medium.

[0162] Thus, embodiments herein may disclose the network node 130 configured to improve terminating call session establishment the wireless communications network 100. The network node 130 comprises the processor 810 and the memory 820, said memory 820 comprising instructions executable by said processor 810 whereby said network node 130 is operative to perform any of the methods herein.

[0163] As will be readily understood by those familiar with communications design, that functions means or modules may be implemented using digital logic and / or one or more microcontrollers, microprocessors, or other digital hardware. In some embodiments, several or all of the various functions may be implemented together, such as in a single application-specific integrated circuit (ASIC), or in two or more separate devices with appropriate hardware and / or software interfaces between them. Several of the functions may be implemented on a processor shared with other functional components of a radio network node, for example.

[0164] Alternatively, several of the functional elements of the processing means discussed may be provided through the use of dedicated hardware, while others are provided with hardware for executing software, in association with the appropriate software or firmware. Thus, the term “processor” or “controller” as used herein does not exclusively refer to hardware capable of executing software and may implicitly include, without limitation, digital signal processor (DSP) hardware, read-only memory (ROM) for storing software, random-access memory for storing software and / or program or application data, and nonvolatile memory. Other hardware, conventional and / or custom, may also be included. Designers of communications receivers will appreciate the cost, performance, and maintenance trade-offs inherent in these design choices.

[0165] Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include digital signal processors (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as read-only memory (ROM), random-access memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and / or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according one or more embodiments of the present disclosure.

[0166] ADDITIONAL EXPLANATION

[0167] 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.

[0168] Figure 9 shows an example of a communication system QQ100 in accordance with some embodiments.

[0169] In the example, the communication system QQ100 includes a telecommunication network QQ102 that includes an access network QQ104, such as a radio access network (RAN), and a core network QQ106, which includes one or more core network nodes QQ108 (being examples of the IMS AS 110). The access network QQ104 includes one or more access network nodes, such as network nodes QQ110a and QQ110b (one or more of which may be generally referred to as network nodes QQ110 being examples of the network node 130), 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 QQ102 includes one or more Open-RAN (ORAN) network nodes. An ORAN network node is a node in the telecommunication network QQ102 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 QQ102, including one or more network nodes QQ110 and / or core network nodes QQ108.

[0170] Examples of an ORAN network node include an open radio unit (0-Rll), an open distributed unit (0-Dll), an open central unit (O-CU), including an O-CU control plane (O- CLI-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 A1, F1, W1, E1 , 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 0-2 interface defined by the O-RAN Alliance or comparable technologies. The network nodes QQ110 facilitate direct or indirect connection of user equipment (UE), such as by connecting UEs QQ112a, QQ112b, QQ112c, and QQ112d (one or more of which may be generally referred to as UEs QQ112 being examples of a UE 121) to the core network QQ106 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 QQ100 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 QQ100 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 QQ112 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 QQ110 and other communication devices. Similarly, the network nodes QQ110 are arranged, capable, configured, and / or operable to communicate directly or indirectly with the UEs QQ112 and / or with other network nodes or equipment in the telecommunication network QQ102 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 QQ102.

[0173] In the depicted example, the core network QQ106 connects the network nodes QQ110 to one or more hosts, such as host QQ116. 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 QQ106 includes one more core network nodes (e.g., core network node QQ108) 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 QQ108. 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 Deconcealing 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 QQ116 may be under the ownership or control of a service provider other than an operator or provider of the access network QQ104 and / or the telecommunication network QQ102, and may be operated by the service provider or on behalf of the service provider. The host QQ116 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. As a whole, the communication system QQ100 of Figure 9 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.

[0175] In some examples, the telecommunication network QQ102 is a cellular network that implements 3GPP standardized features. Accordingly, the telecommunications network QQ102 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network QQ102. For example, the telecommunications network QQ102 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.

[0176] In some examples, the UEs QQ112 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 QQ104 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network QQ104. Additionally, a UE may be configured for operating in single- or multi- RAT or multi-standard 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).

[0177] In the example, the hub QQ114 communicates with the access network QQ104 to facilitate indirect communication between one or more UEs (e.g., UE QQ112c and / or QQ112d) and network nodes (e.g., network node QQ110b). In some examples, the hub QQ114 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub QQ114 may be a broadband router enabling access to the core network QQ106 for the UEs. As another example, the hub QQ114 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 QQ110, or by executable code, script, process, or other instructions in the hub QQ114. As another example, the hub QQ114 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 QQ114 may be a content source. For example, for a UE that is a VR headset, display, loudspeaker or other media delivery device, the hub QQ114 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub QQ114 then provides to the UE either directly, after performing local processing, and / or after adding additional local content. In still another example, the hub QQ114 acts as a proxy server or orchestrator for the UEs, in particular if one or more of the UEs are low energy loT devices.

[0178] The hub QQ114 may have a constant / persistent or intermittent connection to the network node QQ110b. The hub QQ114 may also allow for a different communication scheme and / or schedule between the hub QQ114 and UEs (e.g., UE QQ112c and / or QQ112d), and between the hub QQ114 and the core network QQ106. In other examples, the hub QQ114 is connected to the core network QQ106 and / or one or more UEs via a wired connection. Moreover, the hub QQ114 may be configured to connect to an M2M service provider over the access network QQ104 and / or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes QQ110 while still connected via the hub QQ114 via a wired or wireless connection. In some embodiments, the hub QQ114 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 QQ110b. In other embodiments, the hub QQ114 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node QQ110b, but which is additionally capable of operating as a communication start and / or end point for certain data channels.

[0179] Figure 10 shows a UE QQ200 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-loT) UE, a machine type communication (MTC) UE, and / or an enhanced MTC (eMTC) UE.

[0180] A UE may support device-to-device (D2D) communication, for example by implementing a 3GPP 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).

[0181] The UE QQ200 includes processing circuitry QQ202 that is operatively coupled via a bus QQ204 to an input / output interface QQ206, a power source QQ208, a memory QQ210, a communication interface QQ212, and / or any other component, or any combination thereof. Certain UEs may utilize all or a subset of the components shown in Figure QQ2. 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.

[0182] The processing circuitry QQ202 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 QQ210. The processing circuitry QQ202 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 QQ202 may include multiple central processing units (CPUs). In the example, the input / output interface QQ206 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 QQ200. 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.

[0183] In some embodiments, the power source QQ208 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 QQ208 may further include power circuitry for delivering power from the power source QQ208 itself, and / or an external power source, to the various parts of the UE QQ200 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging of the power source QQ208. Power circuitry may perform any formatting, converting, or other modification to the power from the power source QQ208 to make the power suitable for the respective components of the UE QQ200 to which power is supplied.

[0184] The memory QQ210 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 QQ210 includes one or more application programs QQ214, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data QQ216. The memory QQ210 may store, for use by the UE QQ200, any of a variety of various operating systems or combinations of operating systems. The memory QQ210 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 (eUlCC), integrated UICC (iUICC) or a removable UICC commonly known as ‘SIM card.’ The memory QQ210 may allow the UE QQ200 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 QQ210, which may be or comprise a device-readable storage medium.

[0185] The processing circuitry QQ202 may be configured to communicate with an access network or other network using the communication interface QQ212. The communication interface QQ212 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna QQ222. The communication interface QQ212 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 QQ218 and / or a receiver QQ220 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, the transmitter QQ218 and receiver QQ220 may be coupled to one or more antennas (e.g., antenna QQ222) and may share circuit components, software or firmware, or alternatively be implemented separately.

[0186] In the illustrated embodiment, communication functions of the communication interface QQ212 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.

[0187] Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface QQ212, 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).

[0188] 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.

[0189] 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 smartwatch, 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 QQ200 shown in Figure QQ2.

[0190] 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-loT 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.

[0191] 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.

[0192] Figure 11 shows a network node QQ300 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)), O- RAN nodes or components of an O-RAN node (e.g., O-RU, O-DU, O-CU).

[0193] 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).

[0194] 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- cel l / 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).

[0195] The network node QQ300 includes a processing circuitry QQ302, a memory QQ304, a communication interface QQ306, and a power source QQ308. The network node QQ300 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 QQ300 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 QQ300 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memory QQ304 for different RATs) and some components may be reused (e.g., a same antenna QQ310 may be shared by different RATs). The network node QQ300 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node QQ300, 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 QQ300.

[0196] The processing circuitry QQ302 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 QQ300 components, such as the memory QQ304, to provide network node QQ300 functionality.

[0197] In some embodiments, the processing circuitry QQ302 includes a system on a chip (SOC). In some embodiments, the processing circuitry QQ302 includes one or more of radio frequency (RF) transceiver circuitry QQ312 and baseband processing circuitry QQ314. In some embodiments, the radio frequency (RF) transceiver circuitry QQ312 and the baseband processing circuitry QQ314 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 QQ312 and baseband processing circuitry QQ314 may be on the same chip or set of chips, boards, or units.

[0198] The memory QQ304 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 QQ302. The memory QQ304 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 QQ302 and utilized by the network node QQ300. The memory QQ304 may be used to store any calculations made by the processing circuitry QQ302 and / or any data received via the communication interface QQ306. In some embodiments, the processing circuitry QQ302 and memory QQ304 is integrated.

[0199] The communication interface QQ306 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 QQ306 comprises port(s) / terminal(s) QQ316 to send and receive data, for example to and from a network over a wired connection. The communication interface QQ306 also includes radio front-end circuitry QQ318 that may be coupled to, or in certain embodiments a part of, the antenna QQ310. Radio front-end circuitry QQ318 comprises filters QQ320 and amplifiers QQ322. The radio front-end circuitry QQ318 may be connected to an antenna QQ310 and processing circuitry QQ302. The radio front-end circuitry may be configured to condition signals communicated between antenna QQ310 and processing circuitry QQ302. The radio front-end circuitry QQ318 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 QQ318 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters QQ320 and / or amplifiers QQ322. The radio signal may then be transmitted via the antenna QQ310. Similarly, when receiving data, the antenna QQ310 may collect radio signals which are then converted into digital data by the radio front-end circuitry QQ318. The digital data may be passed to the processing circuitry QQ302. In other embodiments, the communication interface may comprise different components and / or different combinations of components.

[0200] In certain alternative embodiments, the network node QQ300 does not include separate radio front-end circuitry QQ318, instead, the processing circuitry QQ302 includes radio front-end circuitry and is connected to the antenna QQ310. Similarly, in some embodiments, all or some of the RF transceiver circuitry QQ312 is part of the communication interface QQ306. In still other embodiments, the communication interface QQ306 includes one or more ports or terminals QQ316, the radio front-end circuitry QQ318, and the RF transceiver circuitry QQ312, as part of a radio unit (not shown), and the communication interface QQ306 communicates with the baseband processing circuitry QQ314, which is part of a digital unit (not shown).

[0201] The antenna QQ310 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. The antenna QQ310 may be coupled to the radio front-end circuitry QQ318 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, the antenna QQ310 is separate from the network node QQ300 and connectable to the network node QQ300 through an interface or port.

[0202] The antenna QQ310, communication interface QQ306, and / or the processing circuitry QQ302 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 QQ310, the communication interface QQ306, and / or the processing circuitry QQ302 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.

[0203] The power source QQ308 provides power to the various components of network node QQ300 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source QQ308 may further comprise, or be coupled to, power management circuitry to supply the components of the network node QQ300 with power for performing the functionality described herein. For example, the network node QQ300 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 QQ308. As a further example, the power source QQ308 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.

[0204] Embodiments of the network node QQ300 may include additional components beyond those shown in Figure 11 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 QQ300 may include user interface equipment to allow input of information into the network node QQ300 and to allow output of information from the network node QQ300. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node QQ300.

[0205] Figure 12 is a block diagram of a host QQ400, which may be an embodiment of the host QQ116 of Figure 9, in accordance with various aspects described herein. As used herein, the host QQ400 may be or comprise various combinations hardware and / or software, including a standalone server, a blade server, a cloud-implemented server, a distributed server, a virtual machine, container, or processing resources in a server farm. The host QQ400 may provide one or more services to one or more UEs.

[0206] The host QQ400 includes processing circuitry QQ402 that is operatively coupled via a bus QQ404 to an input / output interface QQ406, a network interface QQ408, a power source QQ410, and a memory QQ412. Other components may be included in other embodiments. Features of these components may be substantially similar to those described with respect to the devices of previous figures, such as Figures 14 and QQ3, such that the descriptions thereof are generally applicable to the corresponding components of host QQ400.

[0207] The memory QQ412 may include one or more computer programs including one or more host application programs QQ414 and data QQ416, which may include user data, e.g., data generated by a UE for the host QQ400 or data generated by the host QQ400 for a UE. Embodiments of the host QQ400 may utilize only a subset or all of the components shown. The host application programs QQ414 may be implemented in a container-based architecture and may provide support for video codecs (e.g., Versatile Video Coding (VVC), High Efficiency Video Coding (HEVC), Advanced Video Coding (AVC), MPEG, VP9) and audio codecs (e.g., FLAG, Advanced Audio Coding (AAC), MPEG, G.711), including transcoding for multiple different classes, types, or implementations of UEs (e.g., handsets, desktop computers, wearable display systems, heads-up display systems). The host application programs QQ414 may also provide for user authentication and licensing checks and may periodically report health, routes, and content availability to a central node, such as a device in or on the edge of a core network. Accordingly, the host QQ400 may select and / or indicate a different host for over-the-top services for a UE. The host application programs QQ414 may support various protocols, such as the HTTP Live Streaming (HLS) protocol, Real-Time Messaging Protocol (RTMP), Real-Time Streaming Protocol (RTSP), Dynamic Adaptive Streaming over HTTP (MPEG-DASH), etc.

[0208] Figure 13 is a block diagram illustrating a virtualization environment QQ500 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines (VMs) implemented in one or more virtual environments QQ500 hosted by one or more of hardware nodes, such as a hardware computing device that operates as a network node, UE, core network node, or host. Further, in embodiments in which the virtual node does not require radio connectivity (e.g., a core network node or host), then the node may be entirely virtualized. In some embodiments, the virtualization environment QQ500 includes components defined by the O-RAN Alliance, such as an O- Cloud environment orchestrated by a Service Management and Orchestration Framework via an 0-2 interface.

[0209] Applications QQ502 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment Q400 to implement some of the features, functions, and / or benefits of some of the embodiments disclosed herein. Hardware QQ504 includes processing circuitry, memory that stores software and / or instructions executable by hardware processing circuitry, and / or other hardware devices as described herein, such as a network interface, input / output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers QQ506 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VMs QQ508a and QQ508b (one or more of which may be generally referred to as VMs QQ508), and / or perform any of the functions, features and / or benefits described in relation with some embodiments described herein. The virtualization layer QQ506 may present a virtual operating platform that appears like networking hardware to the VMs QQ508.

[0210] The VMs QQ508 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer QQ506. Different embodiments of the instance of a virtual appliance QQ502 may be implemented on one or more of VMs QQ508, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

[0211] In the context of NFV, a VM QQ508 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each of the VMs QQ508, and that part of hardware QQ504 that executes that VM, be it hardware dedicated to that VM and / or hardware shared by that VM with others of the VMs, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more VMs QQ508 on top of the hardware QQ504 and corresponds to the application QQ502.

[0212] Hardware QQ504 may be implemented in a standalone network node with generic or specific components. Hardware QQ504 may implement some functions via virtualization. Alternatively, hardware QQ504 may be part of a larger cluster of hardware (e.g. such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration QQ510, which, among others, oversees lifecycle management of applications QQ502. In some embodiments, hardware QQ504 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station. In some embodiments, some signaling can be provided with the use of a control system QQ512 which may alternatively be used for communication between hardware nodes and radio units.

[0213] Figure 14 shows a communication diagram of a host QQ602 communicating via a network node QQ604 with a UE QQ606 over a partially wireless connection in accordance with some embodiments. Example implementations, in accordance with various embodiments, of the UE (such as a UE QQ112a of Figure 9 and / or UE QQ200 of Figure QQ2), network node (such as network node QQ110a of Figure 9 and / or network node QQ300 of Figure QQ3), and host (such as host QQ116 of Figure 9 and / or host QQ400 of Figure QQ4) discussed in the preceding paragraphs will now be described with reference to Figure QQ6.

[0214] Like host QQ400, embodiments of host QQ602 include hardware, such as a communication interface, processing circuitry, and memory. The host QQ602 also includes software, which is stored in or accessible by the host QQ602 and executable by the processing circuitry. The software includes a host application that may be operable to provide a service to a remote user, such as the UE QQ606 connecting via an over-the-top (OTT) connection QQ650 extending between the UE QQ606 and host QQ602. In providing the service to the remote user, a host application may provide user data which is transmitted using the OTT connection QQ650.

[0215] The network node QQ604 includes hardware enabling it to communicate with the host QQ602 and UE QQ606. The connection QQ660 may be direct or pass through a core network (like core network QQ106 of Figure QQ1) and / or one or more other intermediate networks, such as one or more public, private, or hosted networks. For example, an intermediate network may be a backbone network or the Internet.

[0216] The UE QQ606 includes hardware and software, which is stored in or accessible by UE QQ606 and executable by the UE’s processing circuitry. The software includes a client application, such as a web browser or operator-specific “app” that may be operable to provide a service to a human or non-human user via UE QQ606 with the support of the host QQ602. In the host QQ602, an executing host application may communicate with the executing client application via the OTT connection QQ650 terminating at the UE QQ606 and host QQ602. In providing the service to the user, the UE's client application may receive request data from the host's host application and provide user data in response to the request data. The OTT connection QQ650 may transfer both the request data and the user data. The UE's client application may interact with the user to generate the user data that it provides to the host application through the OTT connection QQ650.

[0217] The OTT connection QQ650 may extend via a connection QQ660 between the host QQ602 and the network node QQ604 and via a wireless connection QQ670 between the network node QQ604 and the UE QQ606 to provide the connection between the host QQ602 and the UE QQ606. The connection QQ660 and wireless connection QQ670, over which the OTT connection QQ650 may be provided, have been drawn abstractly to illustrate the communication between the host QQ602 and the UE QQ606 via the network node QQ604, without explicit reference to any intermediary devices and the precise routing of messages via these devices.

[0218] As an example of transmitting data via the OTT connection QQ650, in step QQ608, the host QQ602 provides user data, which may be performed by executing a host application. In some embodiments, the user data is associated with a particular human user interacting with the UE QQ606. In other embodiments, the user data is associated with a UE QQ606 that shares data with the host QQ602 without explicit human interaction. In step QQ610, the host QQ602 initiates a transmission carrying the user data towards the UE QQ606. The host QQ602 may initiate the transmission responsive to a request transmitted by the UE QQ606. The request may be caused by human interaction with the UE QQ606 or by operation of the client application executing on the UE QQ606. The transmission may pass via the network node QQ604, in accordance with the teachings of the embodiments described throughout this disclosure. Accordingly, in step QQ612, the network node QQ604 transmits to the UE QQ606 the user data that was carried in the transmission that the host QQ602 initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step QQ614, the UE QQ606 receives the user data carried in the transmission, which may be performed by a client application executed on the UE QQ606 associated with the host application executed by the host QQ602.

[0219] In some examples, the UE QQ606 executes a client application which provides user data to the host QQ602. The user data may be provided in reaction or response to the data received from the host QQ602. Accordingly, in step QQ616, the UE QQ606 may provide user data, which may be performed by executing the client application. In providing the user data, the client application may further consider user input received from the user via an input / output interface of the UE QQ606. Regardless of the specific manner in which the user data was provided, the UE QQ606 initiates, in step QQ618, transmission of the user data towards the host QQ602 via the network node QQ604. In step QQ620, in accordance with the teachings of the embodiments described throughout this disclosure, the network node QQ604 receives user data from the UE QQ606 and initiates transmission of the received user data towards the host QQ602. In step QQ622, the host QQ602 receives the user data carried in the transmission initiated by the UE QQ606.

[0220] One or more of the various embodiments improve the performance of OTT services provided to the UE QQ606 using the OTT connection QQ650, in which the wireless connection QQ670 forms the last segment.

[0221] In an example scenario, factory status information may be collected and analyzed by the host QQ602. As another example, the host QQ602 may process audio and video data which may have been retrieved from a UE for use in creating maps. As another example, the host QQ602 may collect and analyze real-time data to assist in controlling vehicle congestion (e.g., controlling traffic lights). As another example, the host QQ602 may store surveillance video uploaded by a UE. As another example, the host QQ602 may store or control access to media content such as video, audio, VR or AR which it can broadcast, multicast or unicast to UEs. As other examples, the host QQ602 may be used for energy pricing, remote control of non-time critical electrical load to balance power generation needs, location services, presentation services (such as compiling diagrams etc. from data collected from remote devices), or any other function of collecting, retrieving, storing, analyzing and / or transmitting data.

[0222] In some examples, a measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring the OTT connection QQ650 between the host QQ602 and UE QQ606, in response to variations in the measurement results. The measurement procedure and / or the network functionality for reconfiguring the OTT connection may be implemented in software and hardware of the host QQ602 and / or UE QQ606. In some embodiments, sensors (not shown) may be deployed in or in association with other devices through which the OTT connection QQ650 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software may compute or estimate the monitored quantities. The reconfiguring of the OTT connection QQ650 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not directly alter the operation of the network node QQ604. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling that facilitates measurements of throughput, propagation times, latency and the like, by the host QQ602. The measurements may be implemented in that software causes messages to be transmitted, in particular empty or ‘dummy’ messages, using the OTT connection QQ650 while monitoring propagation times, errors, etc.

[0223] 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.

[0224] 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.

[0225] When using the word "comprise" or “comprising” it shall be interpreted as non- limiting, i.e. meaning "consist at least of".

[0226] The embodiments herein are not limited to the preferred embodiments described above. Various alternatives, modifications and equivalents may be used.

Claims

CLAIMS1. A method performed by an Internet Protocol Multimedia Subsystem, IMS, Application Server, AS, (110) for improving terminating call session establishment in a wireless communication network (100), the method comprising: sending (302), to a User Equipment, UE, (121), a first Session Initiating Protocol, SIP, message for establishing a terminating call session in a first domain and a first Radio Access Technology, RAT, upon expiry of a timer, sending (303), towards a network node (130), a second SIP message, which second SIP message indicates that redirection of the UE (121) is required, in response to receiving (304) a third SIP message indicating the UE (121) redirection has been completed, sending (305) a fourth SIP message to the UE (121) for establishing the terminating call session in the first domain and any one out of the first RAT or a second RAT.

2. The method according to claim 1, wherein the second message comprises a SIP CANCEL message.

3. The method according to claim 1-2, wherein receiving (304) the indication comprises enforcing an access selection policy associated to the UE (121).

4. The method according to any of claims 1-3, wherein the method further comprises: upon receiving a SIP INVITE message, activating (301) the access selection policy for the terminating call session to be established, which access selection policy is related to handling a failed call session establishment.

5. The method according to claim 4, wherein the call session handling policy indicates a domain to establish the terminating call session on upon a failure to establish the terminating call session.

6. The method according to any of claims 1-5, wherein the third SIP message further indicates a RAT type the UE (121) has been redirected to.

7. The method according to any of claims 1-6, wherein the first domain comprises a Packet Switched, PS, domain.

8. A computer program (730) comprising instructions, which when executed by a processor (710), causes the processor (710) to perform actions according to any of the claims 1-7.

9. A carrier (740) comprising the computer program (730) of claim 8, wherein the carrier (740) is one of an electronic signal, an optical signal, an electromagnetic signal, a magnetic signal, an electric signal, a radio signal, a microwave signal, or a computer- readable storage medium.

10. A method performed by a network node (130) for improving terminating call session establishment in a wireless communication network (100), wherein the network node (130) is associated with a first Radia Access Technology, RAT, the method comprising: receiving (401) a redirection message indicating that redirection of a User Equipment, UE, (121) is required, triggering (402) a redirection of the UE (121), and sending (403) a redirection complete message towards an Internet Protocol Multimedia Subsystem, IMS, Application Server, AS, (110), indicating that the redirection of the UE (121) has been completed.

11. The method according to claim 10, wherein the redirection message originates from the IMS AS (110).

12. The method according to any of claims 10-11, wherein the redirection message is received (401) in response to a failed terminating call session establishment to the UE (121).

13. The method according to any of claims 10-12, wherein the redirection complete message indicates a RAT type the UE (121) has been redirected to14. The method according to any of claims 10-13, wherein the UE (121) is redirected from the first RAT to a second RAT or from a cell and / or frequency in the first RAT to a different cell and / or frequency in the first RAT.

15. The method according to any of claims 10-14, wherein triggering (402) the redirection of the UE (121) comprises instructing the UE (121) to perform the redirection.

16. A computer program (830) comprising instructions, which when executed by a processor (810), causes the processor (810) to perform actions according to any of the claims 10-15.

17. A carrier (840) comprising the computer program (830) of claim 16, wherein the carrier (840) is one of an electronic signal, an optical signal, an electromagnetic signal, a magnetic signal, an electric signal, a radio signal, a microwave signal, or a computer- readable storage medium.

18. An Internet Protocol Multimedia Subsystem, IMS, Application Server, AS, (110) configured to improve terminating call session establishment in a wireless communication network (100), the IMS AS (130) further being configured to: send, to a User Equipment, UE, (121), a first Session Initiating Protocol, SIP, message adapted to establish a terminating call session in a first domain and a first Radio Access Technology, RAT, upon expiry of a timer, send, towards a network node (130), a second SIP message, which second SIP message is adapted to indicate that redirection of the UE (121) is required, in response to a reception a third SIP message indicating the UE (121) redirection has been completed, send a fourth SIP message to the UE (121) to establish the terminating call session in the first domain and any one out of the first RAT or a second RAT.

19. The IMS AS (110) according to claim 18, wherein the second message is adapted to comprise a SIP CANCEL message.

20. The IMS AS (110) according to claim 18-19, wherein the IMS AS (110) is configured to receive the indication by enforcing an access selection policy associated to the UE (121).

21. The IMS AS (110) according to any of claims 18-20, wherein the IMS AS (110) us further configured to: upon reception of a SIP INVITE message, activate the access selection policy for the terminating call session to be established, which access selection policy is adapted to be related to handle a failed call session establishment.

22. The IMS AS (110) according to claim 21, wherein the call session handling policy is adapted to indicate a domain to establish the terminating call session on upon a failure to establish the terminating call session.

23. The IMS AS (110) according to any of claims 18-22, wherein the third SIP message is further adapted to indicate a RAT type the UE (121) has been redirected to.

24. The IMS AS (110) according to any of claims 18-23, wherein the first domain is adapted to comprise a Packet Switched, PS, domain.

25. A network node (130) configured to improve terminating call session establishment in a wireless communication network (100), wherein the network node (130) is configured to be associated with a first Radia Access Technology, RAT, the network node (130) further being configured to: receive a redirection message adapted to indicate that redirection of a User Equipment, UE, (121) is required, trigger a redirection of the UE (121), and send a redirection complete message towards an Internet Protocol Multimedia Subsystem, IMS, Application Server, AS, (110), adapted to indicate that the redirection of the UE (121) has been completed.

26. The network node (130) according to claim 25, wherein the redirection message is adapted to originate from the IMS AS (110).

27. The network node (130) according to any of claims 25-26, wherein the network node (130) is configured to receive the redirection message in response to a failed terminating call session establishment to the UE (121).

28. The network node (130) according to any of claims 25-27, wherein the redirection complete message is adapted to indicate a RAT type the UE (121) has been redirected to29. The network node (130) according to any of claims 25-28, wherein the UE (121) is adapted to be redirected from the first RAT to a second RAT or from a cell and / or frequency in the first RAT to a different cell and / or frequency in the first RAT.

30. The network node (130) according to any of claims 25-29, wherein the network node (130) is configured to trigger the redirection of the UE (121) by instructing the UE (121) to perform the redirection.

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