Patent Description:
As the development of the core network of a wireless communication system, a technology of control and user plane separation (CUPS) is proposed.

Such as in a 3rd generation partner project technical specification <NUM> (3GPP TS <NUM>), terminologies "SGW-C service area", "SGW-U service area" are used for CUPS. "SGW-C service area" means a service area of a serving gateway control plane function (SGW-C), and "SGW-U service area" means a service area of a serving gateway user plane function (SGW-U).

In this document, a SGW-C service area in CUPS is equivalent to the SGW service area without CUPS. A SGW-U service area in CUPS refers to an area within which a user equipment (UE) may be served by the same SGW-U, thus there is no need to change the SGW-U for the UE in the SGW-U Service Area. The SGW-U Serving Area is known in a SGW-C by means of local configuration or by means of a query of domain name system (DNS query).

As to the separated SGW-U and SGW-U, the SGW-U service area may be smaller than the SGW-C service area. In a 3rd generation partner project technical specification <NUM> (3GPP TS23. <NUM>), one implement solution is proposed. The SGW-C can be partitioned into multiple SGW-C partitions. Each of the SGW-C partition is aligned with the corresponding SGW-U service area. The mobility management entity (MME) treats the SGW-C partition as a traditional SGW without CUPS.

With this function, there will be no additional functional requirement on MME, since the serving area of SGW-C partition and the service area of SGW-U are aligned and MME just treat each SGW-C partition as a separate SGW.

However, such solution may increase an implementation complexity in SGW-C. The complexity resides in how to define the partition, how to manage each partition, how to share the resources (e.g. computing, memory) among the partitions. The function also impacts the DNS server configuration. <CIT> discloses methods for selection of an SGW-U in a wireless communications system. <CIT> discloses methods for selection of an SGW-U in a wireless communications system. 3GPP TR <NUM> v14. <NUM> is a technical report on evaluations of potential architecture enhancements for the separation of user plane functionality from control plane functionality. 3GPP TS <NUM> is a technical specification on stage <NUM> level functionality for control and user plane functionality.

Certain aspects of the present disclosure and their embodiments may provide solutions to these or other challenges. There are, proposed herein, various embodiments which address one or more of the issues disclosed herein.

Through the more detailed description of some embodiments of the present disclosure in the accompanying drawings, the above and other objects, features and advantages of the present disclosure will become more apparent, wherein the same reference generally refers to the same components in the embodiments of the present disclosure.

The claims cover the embodiment of <FIG> and <FIG>. All the other embodiments not covered by the claims are to be considered as mere examples useful to better understand the invention.

As below, specific solutions and embodiments of the present disclosure will be described with figures.

<FIG> is a schematic showing an example part of a network with CUPS. As shown in <FIG>, a SGW-C <NUM> manages a plurality of SWG-Us <NUM>. The plurality of SWG-Us <NUM> serve a plurality of service area <NUM>, including a plurality of tracking area <NUM>. In the SWG-Us <NUM>, a SGW-U1 serves a first service area SA1, and a SGW-U2 serves a second service area SA2. The SGW-C <NUM> may obtain a location of a user equipment <NUM> from a mobility management entity <NUM>.

As in the existing 3GPP TS, for managing SWG-Us <NUM>, the SGW-C may be partitioned into multiple SGW-C partitions <NUM>. For example, a partition P1 is aligned to the SGW-U1, and a partition P2 is aligned to the SGW-U2. In such solution, there are several disadvantages as follows.

The network designs of the SGW-C and SGW-U are coupled closely. Whenever there is a SGW-U network redesign, e.g., service area change of SGW-U or introduction of new SGW-U serving a different area, the SGW-C network needs a redesign. For example, if a SGW-U3 is introduced, a new SGW-C partition P3 may be created. Alternatively, the existing SGW-C partition P1 and SGW-C partition P2 may be combined for the SGW-U3. In either manner, the SGW-C network needs a redesign.

SGW-C needs to be further developed to support the partition function. An implementation complexity in SGW-C may be greatly increased both in hardware and software.

Capital expenditures (CAPEX) and operational expenditures (OPEX) of SGW-C increase. With partition function, additional resource might be needed to serve the same number of users, since the resources may not be able to be shared among all partitions to the maximum extent. Besides, additional cost is needed to operate the increased number of SGW-C partitions.

Extra signaling in network are needed for switching of SGW-C partition. When UE moves between SGW-C partition, more signaling is introduced, e.g., the domain name system (DNS) procedure signaling and the signaling towards old SGW-C partition. The situation becomes worse when SGW-C partition needs to be changed while the SGW-U can be kept, i.e., in case the current SGW-U can serve a wider area than any existing SGW-C partition (P1 or P2) (e.g. as shown in <FIG>, when the SGW-U <NUM> is aligned to P1 and P2).

<FIG> is an exemplary flow chart of a method for a serving gateway control plane function to manage a plurality of serving gateway user plane functions in accordance with some embodiments.

As shown in <FIG>, the method includes: step S201, connecting with the plurality of serving gateway user plane functions; step S202, storing serving area information of the plurality of serving gateway user plane functions; step S203, selecting a first serving gateway user plane function among the plurality of serving gateway user plane functions for a user equipment, according to location of the user equipment and the serving area information of the plurality of serving gateway user plane functions; and step S204, sending serving area information of the first serving gateway user plane function to a mobility management entity.

The serving gateway control plane function (SGW-C) may manage the plurality of serving gateway user plane functions (SGW-U) in CUPS manner, without SGW-C partitions. SGW-C needs not to be updated just for a specific purpose. The cost-efficiency is improved.

<FIG> is an exemplary flow chart of a method for a mobility management entity to communicate with a serving gateway control plane function managing a plurality of serving gateway user plane functions in accordance with some embodiments.

The method includes: step S301, sending, to the serving gateway control plane function, a request to create a session; and step S302, receiving serving area information of a first serving gateway user plane function from the serving gateway control plane function. Corresponding to the method shown in <FIG>, the serving gateway control plane function selects the first serving gateway user plane function among the plurality of serving gateway user plane functions for a user equipment, according to location of the user equipment and the serving area information of the plurality of serving gateway user plane functions.

After the first serving gateway user plane function is selected, the serving area information of a first serving gateway user plane function is sent to the mobility management entity (MME). The MME directly communicates with the SGW-U, without need to communicate with SGW-U partitions. Communication resources are saved.

<FIG> is a procedure schematic showing a first embodiment of the method in accordance with some embodiments. <FIG> shows a procedure of a packet data network (PDN) connection establishment.

In step S41, the UE <NUM> communicates with MME <NUM> (or SGSN), to initiate an attach or a PDN connection establishment or a packet data protocol (PDP) context activation procedure. SGSN means serving GPRS support node. GPRS means general packet radio service. In step S42, the MME <NUM> sends a create session request to SGW-C <NUM>. In step S43, SGW-C <NUM> selects the SGW-U <NUM> based on LTE's location and initiates the packet forwarding control protocol (PFCP) session establishment procedure towards the SGW-U. In step S44, the Attach or PDN Connection Establishment or PDP Context Activation procedure continues in SGW-C <NUM>, SGW-U <NUM>, and a packet data network gateway (PGW) <NUM>. The PGW may also include a control plane function PGW-C and a user plane function PGW-U. In step S45, SGW-C <NUM> sends a create session response to MME <NUM>. In the message, information about serving area (SA) of SGW-U <NUM> is additionally included. In step S46, the MME <NUM> stores the information about SA of SGW-U and the attach or PDN connection establishment or PDP context activation procedure continues.

In embodiments of the present disclosure, as shown in <FIG>, the serving area information of the first serving gateway user plane function (SGW-U <NUM>) is sent in a create session response message.

In embodiments of the present disclosure, the serving area information of a serving gateway user plane function may include a list of tracking areas served by the serving gateway user plane function, as shown in <FIG>. Then, as the procedure shown in <FIG>, the mobility management entity may build a tracking area list for the user equipment, based on the serving area information of the serving gateway user plane function, when the procedure continues.

<FIG> is a procedure schematic showing a second embodiment of the method in accordance with some embodiments. <FIG> shows a procedure of mobility procedure with SGW-C change.

In step S51, a mobility procedure with change to a new SGW-C <NUM> is initiated. The mobility procedure may be either an IDLE mobility or a handover procedure. In step S52, when MME (or SGSN) has changed, the old MME <NUM> includes the SGW-U serving area (SA of SWG-U) information in the context response or forward relocation request message sent to new MME <NUM>. In step S53, new MME <NUM> sends create session request to new SGW-C <NUM>. In step S54, SGW-C <NUM> selects the SGW-U <NUM>, based on UE's location and initiates the PFCP session establishment procedure towards the SGW-U <NUM>. In step S55, for idle mobility procedure or handover procedure wherein core network is not involved in preparation phase (e.g. X2-based handover, X2 is interface between eNodeBs), SGW-C <NUM> sends modify bearer request to PGW <NUM>. The procedure is further handled in PGW <NUM>. For other handover procedure where core network is involved in preparation phase (e.g. S1-basd handover and inter-radio access technology (RAT) handover), PGW <NUM> is involved in step S58. S1 is interface between the radio access network (RAN) and evolved packet core. In step S56, SGW-C <NUM> sends create session response to MME <NUM>. In the message, SGW-U serving area information is additionally included. In step S57, MME <NUM> stores the SGW-U serving area information and the mobility procedure continues. MME <NUM> takes the SGW-U serving area into consideration when building TA list for the UE <NUM>. In step S58, for handover procedure where core network is involved in preparation phase (e.g. S1-basd handover and inter-RAT handover), MME <NUM> sends modify bearer request to SGW-C and then to PGW and the procedure is further handled.

As another exemplary embodiment, a session management function (SMF), instead of SGW-C, may send a user plane function (UPF) serving area information, instead of SGW-U serving area, to an access management function (AMF), instead of MME. The UPF serving area information will facilitate the AMF to build up the registration area for the UE, and when the UE is moving out of UPF serving area, AMF can proactively notify SMF.

<FIG> is an exemplary flow chart showing additional steps of the method in <FIG> in accordance with some embodiments.

As shown in <FIG>, the method for the SGW-C further includes: step S601, receiving, from the mobility management entity, a request for changing the first serving gateway user plane function; step S602, reselecting a second serving gateway user plane function from the plurality of serving gateway user plane functions; step S603, sending serving area information of the second serving gateway user plane function to the mobility management entity; and step S604, deleting a session with the first serving gateway user plane function.

As shown in <FIG>, the method for the MME further includes: step S701, sending, to the serving gateway control plane function, a request for changing the first serving gateway user plane function, in response to that the user equipment moves out of a serving area of the first serving gateway user plane function; and step S702, receiving, from the serving gateway control plane function, serving area information of a second serving gateway user plane function. The second serving gateway user plane function is reselected by the serving gateway control plane function.

In the embodiments, the switch between serving gateway user plane functions managed by the same serving gateway control plane function is efficient, since the serving gateway control plane function needs not to be changed. The procedure and the communication resources are saved.

<FIG> is a procedure schematic showing a third embodiment of the method in accordance with some embodiments. <FIG> shows a procedure of an idle mobility.

In step S81, UE <NUM> moves out the SGW-U serving area of the old SGW-U <NUM>, and a mobility procedure is triggered. The mobility procedure is an idle mobility. In step S82, if the MME (or SGSN) has changed, the old MME <NUM> includes the SGW-U serving area information in the context response message sent to new MME <NUM>. In step S83, either due to that UE <NUM> has moved out of the SGW-U serving area or due to other reasons (e.g., MME change or user location information (ULI) is requested to be reported), MME sends modify bearer request to SGW-C <NUM>. In the message, if ULI is not included, ULI for SGW is included to help SGW-C to reselect the SGW-U. In step S84, since the current SGW-U <NUM> cannot serve the UE any more, SGW-C <NUM> reselects another SGW-U <NUM> based on UE's new location and initiates the PFCP session establishment procedure towards SGW-U. In step S85, since SGW-U is changed, SGW-C <NUM> sends modify bearer request to PGW <NUM>. In this message, new SGW-U F-TEID information is included. F-TEID means fully qualified tunnel endpoint identifier. In step S86, SGW-C <NUM> sends modify bearer response to MME <NUM>. In this message, new SGW-U serving area and new SGW-U F-TEID information are included. In step S87, MME802 stores the new SGW-U serving area and the new SGW-U F-TEID information and the mobility procedure continues. MME <NUM> takes the SGW-U serving area into consideration when building TA list for the UE <NUM>. In step S88, SGW-C <NUM> deletes the old PFCP session associated with the old SGW-U <NUM> by initiating the PFCP session deletion procedure.

In the embodiment, the old SGW-U <NUM> is the first SGW-U and the new SGW-U <NUM> is the second SGW-U.

In the embodiments, the request for changing the first serving gateway user plane function is a modify bearer request as in step S83. The serving area information of the second serving gateway user plane function is sent in a modify bearer response message as in S86. The modify bearer request may include user location information, and the user location information may include the change of the location, the current location, etc. The step S604 in <FIG> may include: sending a packet forwarding control plane session deletion request to the first serving gateway user plane function; and receiving a packet forwarding control plane session deletion response from the first serving gateway user plane function, as in step S88.

In the embodiments, the mobility management entity is changed, the old MME <NUM> sends the serving area information of the first or the second serving gateway user plane function to the new MME <NUM>. The serving area information of the first or the second serving gateway user plane function is sent in a context response or a forward relocation request.

<FIG> is a procedure schematic showing a fourth embodiment of the method in accordance with some embodiments. <FIG> shows a handover procedure wherein core network is involved in a completion phase, rather than preparation phase.

In step S91, UE <NUM> moves out the SGW-U serving area and mobility procedure is triggered. The mobility procedure is handover procedure where core network is not involved in preparation phase (e.g. X2-based handover procedure). The preparation and execution procedure are performed by RAN and UE. In step S92, during handover completion phase, MME <NUM> sends a modify bearer request to SGW-C <NUM>. In the message, if ULI is not included, ULI for SGW is included to help SGW-C to reselect the SGW-U. In step S93, since the old SGW-U <NUM> cannot serve the UE <NUM> any more, SGW-C <NUM> reselects another SGW-U <NUM> based on UE's new location and initiates the PFCP session establishment procedure towards SGW-U <NUM>. In step S94, since SGW-U is changed, SGW-C <NUM> sends a modify bearer request to PGW <NUM>. In this message, new SGW-U F-TEID information is included. In step S95, SGW-C <NUM> sends a modify bearer response to MME <NUM>. In this message, new SGW-U serving area and new SGW-U F-TEID information are included. In step S96, MME <NUM> stores the new SGW-U serving area and the new SGW-U F-TEID information and the mobility procedure continues. MME <NUM> takes the SGW-U serving area into consideration when building TA list for the UE <NUM>. In step S97, SGW-C <NUM> deletes the old PFCP session associated with the old SGW-U <NUM> by initiating the PFCP session deletion procedure.

In the embodiments, MME <NUM> sends an indication of to notify a packet data network gateway to the serving gateway control plane function, in response to that the reselection of the second serving gateway user plane function happens during an idle mode mobility procedure, or during a completion phase of a handover procedure. The serving gateway control plane function notify the packet data network gateway by the modify bearer request as in S94.

<FIG> is a procedure schematic showing a fifth embodiment of the method in accordance with some embodiments. <FIG> shows a handover procedure where core network is involved in preparation phase.

In step <NUM>, UE <NUM> moves out the old SGW-U <NUM> serving area and mobility procedure is triggered. The mobility procedure is the handover procedure where core network is involved in preparation phase (e.g. S <NUM>-based handover or inter-RAT handover). In step <NUM>, if SGSN/MME has changed, in the preparation phase, the old SGSN/MME <NUM> includes the SGW-U serving area information in the Forward Relocation Request message sent to new SGSN/MME <NUM>.

In step <NUM>, since UE <NUM> has moved out of the SGW-U <NUM> serving area, before SGSN/MME <NUM> sends message to RAN side to prepare the resource, SGSN/MME <NUM> firstly sends modify bearer request to SGW-C <NUM> so that SGW-C <NUM> can reselect the SGW-U <NUM> to serve the UE <NUM>. In the message, if ULI is not included, ULI for SGW is included to help SGW-C to reselect the SGW-U. An indication of "no PGW notification" is also included so that SGW-C <NUM> will not forward the modify bearer request to PGW <NUM>. In step <NUM>, since the old SGW-U <NUM> cannot serve the UE <NUM> any more, SGW-C <NUM> reselects another SGW-U <NUM> based on UE's new location and initiates the PFCP session establishment procedure towards SGW-U <NUM>. In step <NUM>, SGW-C <NUM> sends modify bearer response to SGSN/MME <NUM>. In this message, new SGW-U serving area and new SGW-U F-TEID information are included. In step <NUM>, SGSN/MME <NUM> stores the new SGW-U serving area and the new SGW-U F-TEID information. MME <NUM> takes the SGW-U <NUM> serving area into consideration when building TA list for the UE <NUM>. In step <NUM>, the mobility procedure continues and when the UE <NUM> has moved to the target area, MME <NUM> sends another modify bearer request to SGW-C <NUM>. Upon receiving modify bearer request, since SGW-U is successfully changed, SGW-C <NUM> sends modify bearer request to PGW <NUM>. In this message, new SGW-U F-TEID information is included. In step <NUM>, SGW-C <NUM> deletes the old PFCP session associated with the old SGW-U <NUM> by initiating the PFCP session deletion procedure.

In the embodiment, the MME <NUM> sends an indication of not to notify a packet data network gateway to the serving gateway control plane function, in response to that the reselection of the second serving gateway user plane function happens during a preparation phase of a handover procedure. The indication (no PGW notification) is included in the modify bearer request as in S1003, and any kind of flag or identifier may be used. After SGW-U is successfully changed, SGW-C <NUM> sends modify bearer request to PGW <NUM>, to notify PGW <NUM>.

In embodiments of the present disclosure, no partition is needed in the SGW-C. Embodiments of the present disclosure problems avoid problems, such as coupling of SGW-C and SGW-U, implementation complexity in SGW-C, SGW-C CAPEX and OPEX increment, and extra signaling in network.

<FIG> is a block diagram showing the serving gateway control plane function and the mobility management entity in accordance with some embodiments.

As shown in <FIG>, a serving gateway control plane function device <NUM> to manage a plurality of serving gateway user plane functions, may include: a processor <NUM>; and a memory <NUM>. The memory <NUM> contains instructions executable by the processor <NUM>. The serving gateway control plane function device <NUM> is operative to the method described above, such as the methods shown in <FIG>, <FIG>.

As shown in <FIG>, a mobility management entity device <NUM> to communicate with a serving gateway control plane function managing a plurality of serving gateway user plane functions, may include: a processor <NUM>; and a memory <NUM>. The memory <NUM> contains instructions executable by the processor <NUM>. The mobility management entity device <NUM> is operative to the method described above, such as the methods shown in <FIG>, <FIG>.

The embodiments of the present disclosure further provides a computer readable storage medium having a computer program stored thereon. The computer program is executable by a device to cause the device to carry out the method described above, such as the methods shown in <FIG>, <FIG>.

In <FIG>, the processor <NUM> and the processor <NUM> may be any kind of processing component, such as 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 memory <NUM> and the memory <NUM> may be any kind of storage component, such as read-only memory (ROM), random-access memory, cache memory, flash memory devices, optical storage devices, etc..

<FIG> is a schematic showing virtualization apparatus for SGW-C in accordance with some embodiments.

As shown in <FIG>, virtual apparatus <NUM> for SGW-C includes a connection unit <NUM>, a storage unit <NUM>, a selection unit <NUM>, and a communication unit <NUM>. Taking the method in <FIG> as an example, the connection unit <NUM> may perform step S201. The storage unit <NUM> may perform step S202. The selection unit <NUM> may perform step S203. The communication unit <NUM> may further perform step S204.

<FIG> is a schematic showing virtualization apparatus for MME accordance with some embodiments. As shown in <FIG>, virtual apparatus <NUM> for MME includes a communication unit <NUM>. Taking the method in <FIG> as an example, the communication unit <NUM> may perform step S301 and S302.

With virtual apparatus <NUM> and <NUM>, the SGW-C and MME may not need fixed processor or memory, any computing resource and storage resource may be arranged form at least one node device in the network. The introduction of virtualization technology and network computing technology may improve the usage efficiency of the network resources and the flexibility of the network.

<FIG> is a schematic showing a wireless network in accordance with some embodiments.

Although the subject matter described herein may be implemented in any appropriate type of system using any suitable components, the embodiments disclosed herein are described in relation to a wireless network, such as the example wireless network illustrated in <FIG>. For simplicity, the wireless network of <FIG> only depicts network <NUM>, network nodes <NUM> and 1460b, and WDs <NUM>, 1410b, and 1410c. In practice, a wireless network may further include any additional elements suitable to support communication between wireless devices or between a wireless device and another communication device, such as a landline telephone, a service provider, or any other network node or end device. Of the illustrated components, network node <NUM> and wireless device (WD) <NUM> are depicted with additional detail. The wireless network may provide communication and other types of services to one or more wireless devices to facilitate the wireless devices' access to and/or use of the services provided by, or via, the wireless network.

Yet further examples of network nodes include multistandard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell/multicast coordination entities (MCEs), core network nodes (e.g., MSCs, MMEs), O&M nodes, OSS nodes, SON nodes, positioning nodes (e.g., E-SMLCs), and/or MDTs.

As used herein, wireless device (WD) refers to a device capable, configured, arranged and/or operable to communicate wirelessly with network nodes and/or other wireless devices. Unless otherwise noted, the term WD may be used interchangeably herein with user equipment (UE). Communicating wirelessly may involve transmitting and/or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and/or other types of signals suitable for conveying information through air. In some embodiments, a WD may be configured to transmit and/or receive information without direct human interaction. For instance, a WD may be designed to transmit information to a network on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the network. Examples of a WD include, but are not limited to, a smart phone, a mobile phone, a cell phone, a voice over IP (VoIP) phone, a wireless local loop phone, a desktop computer, a personal digital assistant (PDA), a wireless cameras, a gaming console or device, a music storage device, a playback appliance, a wearable terminal device, a wireless endpoint, a mobile station, a tablet, a laptop, a laptop-embedded equipment (LEE), a laptop-mounted equipment (LME), a smart device, a wireless customer-premise equipment (CPE), a vehicle-mounted wireless terminal device, etc.. A WD may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-everything (V2X) and may in this case be referred to as a D2D communication device. As yet another specific example, in an Internet of Things (IoT) scenario, a WD 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 WD and/or a network node. The WD may in this case be a machine-to-machine (M2M) device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the WD may be a UE implementing the 3GPP narrow band internet of things (NB-IoT) standard. Particular examples of such machines or devices are sensors, metering devices such as power meters, industrial machinery, or home or personal appliances (e.g. refrigerators, televisions, etc.) personal wearables (e.g., watches, fitness trackers, etc.). In other scenarios, a WD may represent a vehicle or other equipment that is capable of monitoring and/or reporting on its operational status or other functions associated with its operation. A WD as described above may represent the endpoint of a wireless connection, in which case the device may be referred to as a wireless terminal. Furthermore, a WD as described above may be mobile, in which case it may also be referred to as a mobile device or a mobile terminal.

Network connection interface <NUM> may be configured to provide a communication interface to network 1543a. Network 1543a may encompass wired and/or wireless networks such as a local-area network (LAN), a wide-area network (WAN), a computer network, a wireless network, a telecommunications network, another like network or any combination thereof. For example, network 1543a may comprise a Wi-Fi network.

Storage medium <NUM> may allow UE <NUM> to access computer-executable instructions, application programs or the like, stored on transitory or non-transitory memory media, to offload data, or to upload data.

In <FIG>, processing circuitry <NUM> may be configured to communicate with network 1543b using communication subsystem <NUM>. Network 1543a and network 1543b may be the same network or networks or different network or networks. Communication subsystem <NUM> may be configured to include one or more transceivers used to communicate with network 1543b.

Network 1543b may encompass wired and/or wireless networks such as a local-area network (LAN), a wide-area network (WAN), a computer network, a wireless network, a telecommunications network, another like network or any combination thereof. For example, network 1543b may be a cellular network, a Wi-Fi network, and/or a near-field network.

Access network <NUM> comprises a plurality of base stations 1712a, 1712b, 1712c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 1713a, 1713b, 1713c. Each base station 1712a, 1712b, 1712c is connectable to core network <NUM> over a wired or wireless connection <NUM>. A first UE <NUM> located in coverage area 1713c is configured to wirelessly connect to, or be paged by, the corresponding base station 1712c. A second UE <NUM> in coverage area 1713a is wirelessly connectable to the corresponding base station 1712a.

It is noted that host computer <NUM>, base station <NUM> and UE <NUM> illustrated in <FIG> may be similar or identical to host computer <NUM>, one of base stations 1712a, 1712b, 1712c and one of UEs <NUM>, <NUM> of <FIG>, respectively.

Wireless connection <NUM> between UE <NUM> and base station <NUM> is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to UE <NUM> using OTT connection <NUM>, in which wireless connection <NUM> forms the last segment. More precisely, the teachings of these embodiments may improve the data rate, latency, power consumption, since time and radio resources for managing a plurality of SGW-Us are reduced, and thereby provide benefits such as, reduced user waiting time, and better responsiveness.

In the above mentioned methods and apparatuses, the serving gateway control plane function (SGW-C) may manage the plurality of serving gateway user plane functions (SGW-U) in CUPS manner, without SGW-C partitions. SGW-C needs not to be updated just for a specific purpose. The cost-efficiency is improved. After the first serving gateway user plane function is selected, the serving area information of a first serving gateway user plane function is sent to the mobility management entity (MME). The MME directly communicates with the SGW-U, without need to communicate with SGW-U partitions. Communication resources are saved. Embodiments of the present disclosure problems avoid problems, such as coupling of SGW-C and SGW-U, implementation complexity in SGW-C, SGW-C CAPEX and OPEX increment, and extra signaling in network.

The data rate, latency, power consumption may also be improved, since time and radio resources for managing a plurality of SGW-Us are reduced, and thereby provide benefits such as, reduced user waiting time, better responsiveness. The energy improvement in node equipment and in network level can also be calculated/estimated for the present disclosure.

Claim 1:
A method performed by a serving gateway control plane function (<NUM>) to manage a plurality of serving gateway user plane functions (<NUM>), comprising:
connecting (S201) with the plurality of serving gateway user plane functions (<NUM>);
storing (S202) serving area information of the plurality of serving gateway user plane functions (<NUM>);
selecting (S203) a first serving gateway user plane function (<NUM>, <NUM>) among the plurality of serving gateway user plane functions (<NUM>) for a user equipment (<NUM>), according to location of the user equipment (<NUM>) and the serving area information of the plurality of serving gateway user plane functions (<NUM>);
sending (S204) serving area information of the first serving gateway user plane function (<NUM>, <NUM>) to a mobility management entity (<NUM>);
receiving (S601), from the mobility management entity (<NUM>), a request for changing the first serving gateway user plane function (<NUM>, <NUM>);
reselecting (S602) a second serving gateway user plane function (<NUM>, <NUM>, <NUM>) from the plurality of serving gateway user plane functions (<NUM>);
sending (S603) serving area information of the second serving gateway user plane function (<NUM>, <NUM>, <NUM>) to the mobility management entity; and
deleting (S604) a session with the first serving gateway user plane function (<NUM>, <NUM>); and
any one out of:
receiving, in response to that the reselection of the second serving gateway user plane function (<NUM>, <NUM>, <NUM>) happens during a preparation phase of a handover procedure, an indication of not to notify a packet data network gateway (<NUM>, <NUM>, <NUM>) from the mobility management entity (<NUM>), or
receiving, in response to that the reselection of the second serving gateway user plane function (<NUM>, <NUM>, <NUM>) happens during an idle mode mobility procedure, or during a completion phase of a handover procedure, an indication of to notify a packet data network gateway (<NUM>, <NUM>, <NUM>) from the mobility management entity (<NUM>).