CN117643116A

CN117643116A - Network access method, device, communication equipment and storage medium

Info

Publication number: CN117643116A
Application number: CN202280002507.3A
Authority: CN
Inventors: 刘建宁; 沈洋
Original assignee: Beijing Xiaomi Mobile Software Co Ltd
Current assignee: Beijing Xiaomi Mobile Software Co Ltd
Priority date: 2022-06-30
Filing date: 2022-06-30
Publication date: 2024-03-01
Also published as: WO2024000537A1

Abstract

The embodiment of the invention discloses a network access method, a network access device, a communication device and a storage medium. A User Equipment (UE) accesses a first network through a first third generation partnership project (3 GPP) standard access technology based on a user identity, wherein the UE accesses a second network through a second 3GPP standard access technology based at least on the user identity, wherein the first network is different from the second network (201).

Description

Network access method, device, communication equipment and storage medium

Technical Field

The present application relates to the field of wireless communication technology, but is not limited to the field of wireless communication technology, and in particular, to a network access method, apparatus, communication device, and storage medium.

Background

The fifth generation cellular mobile communication system (5 GS) is capable of supporting data connections providing multiple access technologies above the RAN layer, i.e. two access network paths can be used simultaneously between the UE and the data network for data transmission, and the RAN to 5G core network user plane anchor point also has two independent user plane tunnels. For example, the multiple connection access traffic handoff and offload management technology (Access Traffic Steering Switch and Splitting, ats ss) supports traffic steering, splitting and handoff for one third generation partnership project (3rd Generation Partnership Project,3GPP) standard technology access path and one non-3 GPP standard technology access path.

Disclosure of Invention

In view of this, embodiments of the present disclosure provide a network access method, apparatus, communication device, and storage medium.

According to a first aspect of an embodiment of the present disclosure, there is provided a network access method, which is performed by a User Equipment (UE), including:

and accessing a first network through a first third generation partnership project (3 GPP) standard access technology based on the user identity, wherein the UE accesses a second network through a second 3GPP standard access technology based on at least the user identity, and wherein the first network is different from the second network.

In one embodiment, the accessing the first network through the first 3GPP standard access technology includes:

and registering the first network through the first 3GPP standard access technology, wherein the UE is registered with the second network through the second 3GPP standard access technology at least based on the user identity.

In one embodiment, the registering the first network through the first 3GPP standard access technology includes:

sending, by the first 3GPP standard access technology, a first registration request message requesting registration to the first network to an access and mobility management function (Access and Mobility Management Function, AMF) of the first network, wherein the first registration request message carries a secondary registration identifier, where the secondary registration identifier is used to instruct the UE to request registration to the first network by the first 3GPP standard access technology based on the user identity, and the UE is in a registration state in the second network by the second 3GPP standard access technology based on the user identity.

In one embodiment, the method further comprises,

receiving a registration acceptance message sent by the AMF based on the first registration request message and indicating that the AMF is successfully registered in the first network;

the registration acceptance message is a unified data management function (Unified Data Management, UDM) that the AMF registers the registration information of the UE to the home network of the UE through a second registration request message, and is sent based on receiving the registration response message of the UDM, wherein the second registration request message carries the secondary registration identity.

In one embodiment, the registration response message is sent by the UDM to determine, based on the second registration request message, a first registration management (Registration Management, RM) context to maintain the UE in the first network and a second RM context for the UE in the second network.

In one embodiment, the method further comprises: a first RM context of the UE in the first network and a second RM context of the UE in the second network are maintained.

In one embodiment, the second network comprises one of:

a home network of the UE;

And the UE accesses the network.

In one embodiment, the first network is determined by the UE based on a network identification in a downlink instruction;

and/or the number of the groups of groups,

the first network is detected by the UE.

According to a second aspect of the embodiments of the present disclosure, there is provided a network access method, wherein the execution of the AMF by the first network includes:

determining service parameters for User Equipment (UE), wherein the service parameters are service parameters of the UE accessing a first network through a first 3GPP standard access technology based on a user identity, wherein the UE accesses a second network through a second 3GPP standard access technology based on at least the user identity, and wherein the first network is different from the second network.

In one embodiment, the determining the service parameters for the UE includes:

and determining service parameters for the UE to register to the first network through the first 3GPP standard access technology based on the user identity, wherein the UE is registered to the second network through the second 3GPP standard access technology based at least on the user identity.

In one embodiment, the determining the service parameter for the UE to register to the first network through the first 3GPP standard access technology based on the user identity includes:

Receiving a first registration request message sent by the UE based on the user identity and requesting to register to the first network, wherein the first registration request message carries a secondary registration identifier, the secondary registration identifier is used for indicating that the UE requests to register to the first network through the first 3GPP standard access technology based on the user identity, and the UE is in a registration state in the second network through the second 3GPP standard access technology based on the user identity.

In one embodiment, the determining the service parameters for the UE to register to the first network through the first 3GPP standard access technology based on the user identity includes:

transmitting a second registration request message for registering registration information of the UE to a UDM of a home network of the UE based on the first registration request message; the second registration request message carries an indication of the secondary registration identifier;

and receiving a registration response message sent by the UDM based on the second registration request message.

In one embodiment, the registration response message is sent by the UDM to determine, based on the second registration request message, a first RM context to maintain the UE in the first network and a second RM context to maintain the UE in the second network.

and when receiving the registration response message, sending a registration acceptance message indicating that the registration to the first network is successful to the UE.

In one embodiment, the second network comprises one of:

a home network of the UE;

and the UE accesses the network.

According to a third aspect of embodiments of the present disclosure, there is provided a network access method, wherein the execution of the UDM by the home network, includes:

receiving a second registration request message sent by an access and mobility management function (AMF) of a first network, wherein the second registration request message is used for indicating that registration information of User Equipment (UE) is registered to the UDM, wherein the second registration request message carries a secondary registration identifier, wherein the secondary registration identifier is used for indicating that the UE requests to register to the first network through a first third generation partnership project (3 GPP) standard access technology based on the user identity, and maintaining a registration state in the second network through a second 3GPP standard access technology based on the user identity;

A first registration management, RM, context of the UE in the first network and a second RM context of the UE in the second network are maintained based on the second registration request message.

In one embodiment, the second registration request message is sent by the AMF after receiving a first registration request message, where the first registration request message is sent by the UE to the AMF through the first 3GPP standard access technology based on the user identity, and the first registration request message carries the secondary registration identity.

determining to maintain the first RM context and the second RM context, and sending a registration response message to the AMF.

In one embodiment, the second network comprises one of:

a home network of the UE;

and the UE accesses the network.

According to a fourth aspect of embodiments of the present disclosure, there is provided a network access device disposed in a user equipment UE; wherein, include:

and the receiving and transmitting module is configured to access a first network through a first third generation partnership project (3 GPP) standard access technology based on a user identity, wherein the UE accesses a second network through a second 3GPP standard access technology based on at least the user identity, and the first network is different from the second network.

In one embodiment, the transceiver module is specifically configured to:

In one embodiment, the transceiver module is configured to:

sending a first registration request message requesting to register to the first network to an AMF of the first network through the first 3GPP standard access technology, wherein the first registration request message carries a secondary registration identifier, the secondary registration identifier is used for indicating that the UE requests to register to the first network through the first 3GPP standard access technology based on the user identity, and the UE is in a registration state in the second network through the second 3GPP standard access technology based on the user identity.

In one embodiment, the transceiver module is further configured to:

receiving a registration acceptance message sent by the AMF based on the first registration request message and indicating successful registration to the first network;

the registration acceptance message is sent by the AMF by registering the registration information of the UE to a UDM of a home network of the UE through a second registration request message, and based on receiving a registration response message of the UDM, where the second registration request message carries the secondary registration identifier.

In one embodiment, the apparatus further comprises: a processing module configured to maintain a first RM context of the UE in the first network and a second RM context of the UE in the second network.

In one embodiment, the second network comprises one of:

a home network of the UE;

and the UE accesses the network.

and/or the number of the groups of groups,

the first network is detected by the UE.

According to a fifth aspect of embodiments of the present disclosure, there is provided a network access device disposed within an AMF of a first network of a user equipment UE; wherein, include:

and the receiving and transmitting module is configured to determine service parameters for User Equipment (UE), wherein the service parameters are service parameters of the UE for accessing a first network through a first 3GPP standard access technology based on a user identity, wherein the UE accesses a second network through a second 3GPP standard access technology based at least on the user identity, and wherein the first network is different from the second network.

In one embodiment, the transceiver module is specifically configured to:

In one embodiment, the second network comprises one of:

a home network of the UE;

and the UE accesses the network.

According to a sixth aspect of embodiments of the present disclosure, there is provided a network access device disposed within a UDM of a home network of a user equipment UE; wherein, include:

a transceiver module configured to receive a second registration request message sent by an access and mobility management function AMF of a first network, where the second registration request message is configured to instruct to register registration information of a user equipment UE to the UDM, where the second registration request message carries a secondary registration identifier, where the secondary registration identifier is configured to instruct the UE to request to register to the first network through a first third generation partnership project (3 GPP) standard access technology based on the user identity, and maintain a registration state in the second network through a second 3GPP standard access technology based on the user identity; a first registration management, RM, context of the UE in the first network and a second RM context of the UE in the second network are maintained based on the second registration request message.

In one embodiment, the transceiver module is specifically configured to:

In one embodiment, the second network comprises one of:

a home network of the UE;

and the UE accesses the network.

According to a seventh aspect of embodiments of the present disclosure, there is provided a communication device apparatus comprising a processor, a memory and an executable program stored on the memory and capable of being executed by the processor, wherein the processor performs the steps of the network access method according to the first or second or third aspect when the executable program is executed by the processor.

According to an eighth aspect of embodiments of the present disclosure, there is provided a storage medium having stored thereon an executable program, wherein the executable program when executed by a processor implements the steps of the network access method according to the first or second or third aspect.

According to the network access method, the network access device, the communication equipment and the storage medium provided by the embodiment of the disclosure, the UE accesses a first network through a 3GPP standard access technology based on a user identity, wherein the UE accesses a second network through a second 3GPP standard access technology based at least on the user identity, and the first network is different from the second network. Therefore, the UE accesses the first network and the second network respectively through the first 3GPP standard access technology and the second 3GPP standard access technology based on one user identity, so that the flexibility of accessing the network is improved, and the requirements of different communication scenes are met. The data of the two networks can be aggregated or backed up mutually, so that the data throughput and the data transmission reliability are improved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of embodiments of the disclosure.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the embodiments of the invention.

Fig. 1 is a schematic diagram of a wireless communication system according to an exemplary embodiment;

FIG. 2 is a flow diagram illustrating a network access method according to an example embodiment;

FIG. 3 is a flow chart illustrating a method of network access according to an exemplary embodiment;

FIG. 4 is a flow chart illustrating a method of network access according to an exemplary embodiment;

FIG. 5 is a flow diagram illustrating a network access method according to an example embodiment;

FIG. 6 is a flow chart illustrating a method of network access according to an example embodiment;

FIG. 7 is a block diagram of a network access device, according to an example embodiment;

FIG. 8 is a block diagram of a network access device, according to an example embodiment;

FIG. 9 is a block diagram of a network access device, according to an example embodiment;

fig. 10 is a block diagram illustrating an apparatus for network access according to an example embodiment.

Detailed Description

Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with embodiments of the invention. Rather, they are merely examples of apparatus and methods consistent with aspects of embodiments of the invention as detailed in the accompanying claims.

The terminology used in the embodiments of the disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the embodiments of the disclosure. As used in this disclosure and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any or all possible combinations of one or more of the associated listed items.

It should be understood that although the terms first, second, third, etc. may be used in embodiments of the present disclosure to describe various information, these information should not be limited to these terms. These terms are only used to distinguish one type of information from another. For example, the first information may also be referred to as second information, and similarly, the second information may also be referred to as first information, without departing from the scope of embodiments of the present disclosure. The word "if" as used herein may be interpreted as "at … …" or "at … …" or "responsive to a determination", depending on the context.

Referring to fig. 1, a schematic structural diagram of a wireless communication system according to an embodiment of the disclosure is shown. As shown in fig. 1, the wireless communication system is a communication system based on a cellular mobile communication technology, and may include: a number of terminals 11 and a number of base stations 12.

Where the terminal 11 may be a device providing voice and/or data connectivity to a user. The terminal 11 may communicate with one or more core networks via a radio access network (Radio Access Network, RAN), and the terminal 11 may be an internet of things terminal such as a sensor device, a mobile phone (or "cellular" phone) and a computer with an internet of things terminal, for example, a stationary, portable, pocket, hand-held, computer-built-in or vehicle-mounted device. Such as a Station (STA), subscriber unit (subscriber unit), subscriber Station (subscriber Station), mobile Station (mobile Station), mobile Station (mobile), remote Station (remote Station), access point, remote terminal (remote terminal), access terminal (access terminal), user equipment (user terminal), user agent (user agent), user device (user equipment), or user terminal (UE). Alternatively, the terminal 11 may be an unmanned aerial vehicle device. Alternatively, the terminal 11 may be a vehicle-mounted device, for example, a car-driving computer having a wireless communication function, or a wireless communication device externally connected to the car-driving computer. Alternatively, the terminal 11 may be a roadside device, for example, a street lamp, a signal lamp, or other roadside devices having a wireless communication function.

The base station 12 may be a network-side device in a wireless communication system. Wherein the wireless communication system may be a fourth generation mobile communication technology (the 4th generation mobile communication,4G) system, also known as a long term evolution (Long Term Evolution, LTE) system; alternatively, the wireless communication system may be a 5G system, also known as a New Radio (NR) system or a 5G NR system. Alternatively, the wireless communication system may be a next generation system of the 5G system. Among them, the access network in the 5G system may be called NG-RAN (New Generation-Radio Access Network, new Generation radio access network). Or, an MTC system.

Wherein the base station 12 may be an evolved base station (eNB) employed in a 4G system. Alternatively, the base station 12 may be a base station (gNB) in a 5G system employing a centralized and distributed architecture. When the base station 12 employs a centralized and distributed architecture, it typically includes a Centralized Unit (CU) and at least two Distributed Units (DUs). A protocol stack of a packet data convergence protocol (Packet Data Convergence Protocol, PDCP) layer, a radio link layer control protocol (Radio Link Control, RLC) layer, and a medium access control (Media Access Control, MAC) layer is provided in the centralized unit; a Physical (PHY) layer protocol stack is provided in the distribution unit, and the specific implementation of the base station 12 is not limited by the embodiment of the present disclosure.

A wireless connection may be established between the base station 12 and the terminal 11 over a wireless air interface. In various embodiments, the wireless air interface is a fourth generation mobile communication network technology (4G) standard-based wireless air interface; or, the wireless air interface is a wireless air interface based on a fifth generation mobile communication network technology (5G) standard, for example, the wireless air interface is a new air interface; alternatively, the wireless air interface may be a wireless air interface based on a 5G-based technology standard of a next generation mobile communication network.

In some embodiments, an E2E (End to End) connection may also be established between terminals 11. Such as V2V (vehicle to vehicle, vehicle-to-vehicle) communications, V2I (vehicle to Infrastructure, vehicle-to-road side equipment) communications, and V2P (vehicle to pedestrian, vehicle-to-person) communications among internet of vehicles communications (vehicle to everything, V2X).

In some embodiments, the above wireless communication system may further comprise a network management device 13.

Several base stations 12 are connected to a network management device 13, respectively. The network management device 13 may be a core network device in a wireless communication system, for example, the network management device 13 may be a mobility management entity (Mobility Management Entity, MME) in an evolved packet core network (Evolved Packet Core, EPC). Alternatively, the network management device may be other core network devices, such as a Serving Gateway (SGW), a public data network gateway (Public Data Network Gate Way, PGW), a policy and charging rules function (Policy and Charging Rules Function, PCRF) or a home subscriber server (Home Subscriber Server, HSS), etc. The embodiment of the present disclosure is not limited to the implementation form of the network management device 13.

In some scenarios, it may be desirable to access path allocation and/or aggregate traffic using two 3GPP standard technologies, such as:

1. two 3GPP standard technology access paths in the same public land mobile network (Public Land Mobile Network, PLMN), e.g. one path using long term evolution technology (Long Term Evolution, LTE)/packet core evolution (Evolved Packet Core, EPC) and another path using New Radio, NR)/5G core network (5 GC); or two paths using 3GPP Non-terrestrial network (Non-Terrestrial Networks, NTN) access, for example, through Low Earth Orbit (LEO) satellites and medium Earth Orbit (medium Earth orbits, MEO)/geosynchronous Orbit (Geosynchronous Earth Orbit, GEO).

2. Two different PLMN access paths, or two 3GPP access paths between a PLMN and a Non-Public Network (NPN), e.g., one path using 3GPP NTN to access PLMN-1 and the other path using 3GPP terrestrial to access PLMN-2 (or NPN); two 3GPP terrestrial access paths may also be included, using the same radio access technology (RAT, radio Acess Technology) (e.g., NR & NR, NTN & NTN) or different RATs (e.g., NR plus LTE).

In all embodiments of the present disclosure, a 3GPP standard technology access path refers to an access path that conforms to the communication protocol specification specified by the 3GPP organization.

In these cases, it would be beneficial to enable an additional 5GS mechanism under mobile network operator (Mobile Network Operator, MNO) control/policy to provide flexible user plane traffic aggregation, steering, and switching. These mechanisms may improve access and network resource utilization, capacity, coverage, reliability, and quality of user experience (QoE).

For scenarios involving interworking between two PLMNs (or PLMNs plus NPN), it may be assumed that the two networks are managed by the same MNO or different partner MNOs (with some business agreements). In the latter case, the inter-MNO protocol will include appropriate incentive measures and policies regarding how to manage and route traffic across the network, not within the scope of this study.

Terrestrial plus satellite access (single or multiple PLMNs): the additional resources available to the NTN network may be used to extend the capacity/data throughput (Tput) of the terrestrial network and vice versa. The opportunity to use traffic aggregation (or selection/handoff) may be based on demand or temporary coverage conditions. For example, for a UE in a train/cruise ship/airplane (typically served by NTN), a stopover is reached (NTN and TN dual coverage may be used).

Traffic aggregation/splitting may be used to extend bandwidth/Tput through multi-satellite access, such as through LEO and MEO/GEO networks. In addition, traffic steering and handoff over different types of satellite access may be better controlled, e.g., based on application delay or bandwidth requirements, LEO discontinuous coverage, etc.

In a particular area or venue, such as a stadium during high data traffic activity, the available resources of the local network (NPN or PLMN 2) may be used to provide additional capacity wide area PLMN1 network and vice versa. Similar scenarios may apply to other local environments, such as campuses, businesses, factories, homes.

Currently, a UE (a user identity) can register to two PLMNs through one 3GPP standard technology access path and one non-3 GPP standard technology access path, and cannot support two 3GPP standard technology access paths.

As shown in fig. 2, the present exemplary embodiment provides a network access method, which may be performed by a UE of a cellular mobile communication system, including:

step 201: and accessing a first network through a first 3GPP standard access technology based on the user identity, wherein the UE accesses a second network through a second 3GPP standard access technology based on at least the user identity, and the first network is different from the second network.

The network can identify a unique cellular mobile communications network user by means of a user identity. The user identity may include, but is not limited to, one of the following: international mobile subscriber identity (International Mobile Subscriber Identity, IMSI), subscriber permanent identity (Subscription Permanent Identifier, SUPI), globally unique temporary UE identity (Globally Unique Temporary UE Identity, GUTI), unique account number configured by the operator.

In one possible implementation, a subscriber identity may correspond to a subscriber identity module (Subscriber Identity Module, SIM). The user identity may include user identification information that the USIM may store for the user. The SIMs may include, but are not limited to, the SIMs employed by 2G, and the global subscriber identity cards (Universal Subscriber Identity Module, USIM) employed by 3G to 5G, as well as other forms of SIMs employed by subsequent cellular mobile communications systems. The USIM may include, but is not limited to, at least one of the following: solid USIM and electronic USIM (eUSIM).

In one possible implementation, the UE may access the first network and the second network based on user identification information for the user in the USIM.

In this embodiment, if no special description is given, the UE accesses (including registration, access, data transmission, etc.) the first network and the second network, which are both accessed (including registration, access, data transmission, etc.) by the UE based on the same user identity. Wherein the first network may be a first 3GPP standard technology access path employing a first 3GPP standard access technology and the second network may be a second 3GPP standard technology access path employing a second 3GPP standard access technology.

Here, the first network and the second network may be cellular mobile communication networks. Cellular mobile communication networks include, but are not limited to, at least one of: public land mobile Network (Public Land Mobile Network, simply referred to as PLMN), non-Public Network (NPN).

The first network and the second network may be different types of networks, for example the first network may be a PLMN and the second network may be an NPN.

The first network and the second network may be networks of the same type but managed by different MNOs, or may be two different networks managed by the same MNO. For example, the first network and the second network may be two different PLMNs.

In one possible implementation, the first 3GPP standard access technology and the second 3GPP standard access technology may be the same radio access technology (RAT, radio Acess Technology). For example, the first 3GPP standard access technology and the second 3GPP standard access technology may both be NR, NTN, LTE, or the like.

In one possible implementation, the first 3GPP standard access technology and the second 3GPP standard access technology may be different access technologies. For example, the first 3GPP standard access technology can be NR and the second 3GPP standard access technology can be LTE.

As another example, the first 3GPP standard access technology may be a terrestrial access technology of 3GPP and the second 3GPP standard access technology may be an NTN of 3 GPP. The ground access technology may include, among other things, access through a ground base station, and the like. NTN may include access through Low Earth Orbit (LEO) satellites, medium Earth Orbit (medium Earth orbits, MEO), and/or geosynchronous Orbit (Geosynchronous Earth Orbit, GEO), etc.

In one possible implementation, the first 3GPP standard access technology and the second 3GPP standard access technology are different NTN access modes.

For example, the first 3GPP standard access technology can be an access technology through a LEO satellite, and the second 3GPP standard access technology can be an access technology through a MEO satellite.

Here, the UE may access the first network and the second network through the first 3GPP standard access technology and the second 3GPP standard access technology, respectively, based on one user identity. Wherein accessing the first network and the second network comprises at least one of: registering with the first network and the second network, communicating data with the first network and the second network, and the like. Namely, at the same moment, the UE can be in a registration state in the first network through a user identity, through the first 3GPP standard access technology, and also in a registration state in the second network through the second 3GPP standard access technology, and can perform data communication on the first network and the second network.

For example, the UE may be in a registration state with the PLMN1 via the base station 1 and also in a registration state with the PLMN2 via the base station 2 based on a subscriber identity. The UE may access PLMN1 and PLMN2 through base station 1 and base station 2, respectively.

Here, the UDM of the home network of the UE may determine service parameters of the UE accessing the first network and the second network. Here, the service parameters may include, but are not limited to, at least one of: data transmitted by the UE in the process of registering to the first network and the second network, maintenance of UE information when the UE registers to the first network and the second network at the same time, management and control of the transmitted data, and the like. Thereby meeting the requirement of the UE for accessing the first network and the second network.

For example, the UDM of the home network may store and maintain one context information for the UE in the first network and the second network, respectively. The UE is enabled to connect to both the first network and the second network. Here, the UE simultaneously connecting to the first network and the second network may include: the UE registers with both the first network and the second network, data communication between the UE and the first network and the second network, and so on.

The data communication between the UE and the first network and the data communication between the UE and the second network may occur simultaneously or in a time sharing manner.

It should be understood that the first network and the second network are only used to distinguish between the two networks. The first network may also be referred to as a second network, and the second network may also be referred to as a first network, without departing from the scope of embodiments of the present disclosure.

In one possible implementation, the UE may register with both networks sequentially or simultaneously. For example, the UE may register with the first network before registering with the second network; or the UE may register with the second network before registering with the first network.

In this embodiment, the UE may register with the second network and then register with the first network is described as an example.

After the UE registers with the second network, access to the first network may be initiated, such as registration, etc. The AMF of the first network may determine service parameters of the UE, and the AMF of the first network may include, but is not limited to, at least one of: data transmitted by the UE in the process of registering to the first network and the second network, maintenance of UE information when the UE registers to the first network and the second network at the same time, management and control of the transmitted data, and the like. Thereby meeting the requirement of the UE for accessing the first network and the second network. For example, the AMF may indicate to the core network element that the UE has registered with the second network when it is determined that the UE has registered with the second network and that the UE initiates access to the first network; alternatively, the UE has two context information corresponding to the first network and the second network, respectively.

In one embodiment, the second network comprises one of:

a home network of the UE;

and the UE accesses the network.

In one possible implementation, the second network may be a home network (e.g., hPLMN) of the UE, and the UE may register with the home network before accessing the first network based on the user identity. The context information of the UE for both the first network and the second network may be stored in the home network (e.g., hPLMN) of the UE.

In one possible implementation, the second network may be a visited network (e.g., a vpplmn) where the UE roams, and the UE may register with the visited network before accessing the first network based on the user identity. The context information of the UE for both the first network and the second network may be stored in the home network (e.g., hPLMN) of the UE.

The UE is simultaneously accessed to the first network and the second network, so that the requirements of different application scenes can be met, for example, the traffic of the first network and the traffic of the second network can be aggregated, and the data throughput is improved. When the communication quality of one network is poor, the data transmission can be still maintained through the other network, and the data transmission reliability is improved.

Therefore, the UE accesses the first network and the second network respectively through the first 3GPP standard access technology and the second 3GPP standard access technology based on one user identity, so that the flexibility of accessing the network is improved, and the requirements of different communication scenes are met. The data of the two networks can be aggregated or backed up mutually, so that the data throughput and the data transmission reliability are improved.

In one possible approach, the UE may be registered with the first network through the first 3GPP standard access technology and with the second network through the second 3GPP standard access technology based on the same user identity. I.e. the UE may be in registration in both the first network and the second network based on the same subscriber identity (which may be stored in the same SIM as an example) at the same time.

Here, the UE may initiate registration of the first network and the second network at the same time when registering with the first network and the second network at the same time; it is also possible to register one network before registering another network.

In one possible implementation, the UE may register with the second network first and then with the first network based on the same user identity.

The UDM of the home network may determine that the UE corresponds to a context of the first network and the second network, respectively, during registration of the UE to the first network and the second network, to enable simultaneous registration of the UE to the first network and the second network.

The AMF of the first network may determine whether the UE has registered in the second network, and if the UE has registered in the second network, the AMF of the first network may instruct a core network (e.g., a core network of a home network) to request the UE to register in both the first network and the second network. The AMF of the first network may request authentication or the like from the core network to determine whether to allow the UE to register with the first network and the second network at the same time. The AMF of the first network may also perform transmission of data that the UE registers with the first network when the core network (e.g., the core network of the home network) allows the UE to register with the first network and the second network based on the same SIM.

The UE may register with the second network first and then with the first network based on the same user identity. The UE may send a first registration request message to an AMF of the first network. The first registration request message may carry a secondary registration identifier, which is used to instruct the UE to request to register to the first network through the first 3GPP standard access technology, based on the same user identity, in the case that the UE has registered to the second network through the second 3GPP standard access technology. I.e. the UE may be in a registered state in both the first network and the second network.

In one possible implementation, the UE may send a registration request message to the AMF over an access network (e.g., NG-RAN) in the selected first network. The registration request message may carry a secondary registration identifier, which indicates that the UE performs secondary registration.

In one possible implementation, the UE may be triggered by the UE, the second network, an application, and/or a particular service, etc., to initiate registration with the first network after registering with the second network.

In one embodiment of the present invention, in one embodiment,

the first network is determined by the UE based on a network identifier in a downlink instruction;

and/or the number of the groups of groups,

the first network is detected by the UE.

The UE may select a first network to access before registering with the first network.

In one possible implementation, the first network may be indicated by a downlink instruction sent by the network side, e.g., the network side of the second network, to the UE. The downlink instruction may carry a network identifier of the first network. The UE determines a first network to register based on the downlink instruction.

In one possible implementation, the first network may be UE detected. For example, the detection may be performed when the UE monitors the network using the first 3GPP standard access technology during the random access procedure.

Illustratively, the first network may broadcast, e.g., broadcast a Synchronization Signal Block (SSB), via a base station and/or satellite, etc., and the UE may listen to the SSB to enable discovery of the first network.

In one possible implementation, the second network may be a home network. The UE registers to the home network in the initial random access, and determines a first network and registers based on external or UE own triggers.

In one possible implementation, the second network may be a roaming visited network. The UE registers with the home network in the initial random access, registers with the visited network in the roaming process, and after the UE accesses the visited network, the UE may re-register with the first network in case of registering with the second network based on triggers of the UE, the second network, the application and/or the specific service.

As shown in fig. 3, the present exemplary embodiment provides a network access method, which may be performed by a UE of a cellular mobile communication system, including:

step 301: receiving a registration acceptance message sent by the AMF based on the first registration request message and indicating successful registration to the first network;

Step 301 may be implemented alone or in combination with step 201.

After the AMF of the first network receives the first registration request message, the registration information of the UE, such as the connection management (Connection Management, CM) CM context of the UE, may be carried in the UDM sent to the home network of the UE in the second registration request message. The second registration request message may carry a second registration identifier, which indicates the UE to perform a second registration, that is, to re-register with the first network when registering with the second network.

The UDM of the home network receives the second registration request message sent by the AMF of the first network, and if the UE is allowed to perform the secondary registration, the UDM of the home network may return a registration response message to the AMF of the first network indicating that the UE is allowed to perform the secondary registration.

After the AMF of the first network receives the registration response message, a registration acceptance message may be sent to the UE, indicating successful registration with the first network. The registration accept message may also carry parameters of the first 3GPP standard access technology of the first network.

During registration of the UE with the second network (including the home network or the visited network), the UDM of the home network may store a second RM context for the UE and maintain the second RM context.

The UDM of the home network receives the second registration request message sent by the AMF of the first network, and if the UE is allowed to perform secondary registration, the UDM of the home network may determine a first RM context of the UE in the first network based on registration information (e.g., CM context) of the UE. And determining to maintain the first RM context and the second RM context simultaneously.

After receiving the registration accept message, the UE may maintain a first RM context and a second RM context. Thereby enabling the UE to access the first network through the first 3GPP standard access technology and to access the second network through the second 3GPP standard access technology simultaneously.

As shown in fig. 4, the present exemplary embodiment provides a network access method, which may be performed by an AMF of a first network, including:

step 401: determining service parameters for the UE, wherein the service parameters are service parameters of the UE accessing the first network through the first 3GPP standard access technology based on the user identity; the UE accesses a second network through a second 3GPP standard access technology at least based on the user identity, wherein the first network is different from the second network.

The limitation of the technical solution executed by the UE is the same as that in step 201 and step 301, and the detailed description is not repeated here.

In one embodiment, the determining the service parameters for the UE includes:

receiving a first registration request message sent by the UE based on the user identity and requesting to register to the first network, wherein the first registration request message carries a secondary registration identity, the secondary registration identity is used for indicating that the UE requests to register to the first network through the first 3GPP standard access technology based on the user identity, and the UE is in a registration state in the second network through the second 3GPP standard access technology based on the user identity.

The limitation of the technical schemes executed by the UE, the AMF of the first network, and the UDM of the second network is the same as in step 201 and step 301, and the detailed description thereof will not be repeated. As shown in fig. 5, the present exemplary embodiment provides a network access method, which may be performed by a UDM of a home network of a UE, including:

step 501: receiving a second registration request message sent by an AMF of a first network, wherein the second registration request message is used for indicating to register registration information of User Equipment (UE) to the UDM, wherein the second registration request message carries a secondary registration identifier, and the secondary registration identifier is used for indicating the UE to request to register to the first network through a first 3GPP standard access technology based on the user identity and maintaining a registration state in the second network through a second 3GPP standard access technology based on the user identity; based on the second registration request message, a first RM context of the UE in the first network and a second RM context of the UE in the second network are maintained.

The limitation of the technical scheme executed by the UE is the same as that in step 201 and steps 301 and 401, and the detailed description is not repeated here. The definition of the technical solution executed by the AMF of the first network is the same as that in step 201 and steps 301 and 401, and the detailed description thereof will not be repeated here.

In one possible approach, the UE may be registered with the first network through the first 3GPP standard access technology and with the second network through the second 3GPP standard access technology based on the same user identity. I.e. the UE may be in a registered state in both the first network and the second network based on the same SIM at the same time.

A specific example is provided below in connection with any of the embodiments described above:

in the roaming scenario, the UE first accesses the visited network, network-2 (second network), and then registers with network-1 (first network). As shown in fig. 6, the specific steps include:

step 601: the UE performs network selection and registration with the network-2 according to the roaming procedure, and the AMF of the network-2 sends a second registration request message to the UDM of the home network (e.g., HPLMN) to register the UE with the network-2.

Step 602: the UE decides to trigger a secondary registration with network-1 (network-1 may be vPLMN, NPN, NTN, etc.), e.g., the UE may trigger a secondary registration with network-1 based on a particular service/application. The secondary registration may be when the UE registers with network-2 while registering with network-1.

Step 603: the UE performs network selection to select network-1 by two possible options:

1. network-1 is selected based on an upper level instruction that includes a target network identification, i.e., the network identification of network-1.

2. Defining secondary network selection, reusing normal network selection flow, only excluding registered network and equivalent network.

Step 604: the UE sends a first registration request message to the AMF through the NG-RAN of the network-1 in the selected network-1, wherein the first registration request message comprises a secondary registration identifier and indicates the UE to perform secondary registration on the network-1.

Step 605: the AMF in network-1 registers a registration message (e.g., CM context) with the UDM of the home network.

Step 606: the home network receives the second registration request message with the secondary registration identity, and the UDM maintains RM contexts for the 3GPP access types of network-1 and network-2, respectively.

Step 607: the UDM of the home network sends a registration response message to the AMF in network-1

Step 608: the AMF sends a registration accept message to the UE including the 3GPP access parameters. The UE maintains RM contexts for the 3GPP access of network-1 and the 3GPP access of network-2, respectively.

For the non-roaming case, the UE registers directly with the HPLMN. The rest of the process is similar to steps X02 to X08, and will not be described again here.

The embodiment of the present invention also provides a network access device, as shown in fig. 7, applied to a UE in cellular mobile radio communication, where the device 100 includes:

the transceiver module 110 is configured to access a first network through a first third generation partnership project, 3GPP, standard access technology based on a user identity, wherein the UE accesses a second network through a second 3GPP standard access technology based at least on the user identity, wherein the first network is different from the second network.

In one embodiment, the transceiver module 110 is specifically configured to:

In one embodiment, the transceiver module 110 is configured to:

In one embodiment, the transceiver module 110 is further configured to:

In one embodiment, the apparatus further comprises: a processing module 120 is configured to maintain a first RM context of the UE in the first network and a second RM context of the UE in the second network.

In one embodiment, the second network comprises one of:

a home network of the UE;

and the UE accesses the network.

And/or the number of the groups of groups,

the first network is detected by the UE.

The embodiment of the present invention further provides a network access device, as shown in fig. 8, applied to an AMF of a first network, where the device 200 includes:

the transceiver module 210 is configured to determine a service parameter for a user equipment UE, where the service parameter is a service parameter of the UE accessing a first network through a first 3GPP standard access technology based on a user identity, where the UE accesses a second network through a second 3GPP standard access technology based at least on the user identity, where the first network is different from the second network.

In one embodiment, the transceiver module 210 is specifically configured to:

In one embodiment, the second network comprises one of:

a home network of the UE;

and the UE accesses the network.

The embodiment of the present invention further provides a network access device, as shown in fig. 9, applied to UDM of a home network, where the device 300 includes:

A transceiver module 310 configured to receive a second registration request message sent by an access and mobility management function AMF of a first network, where the second registration request message is configured to instruct to register registration information of a user equipment UE to the UDM, where the second registration request message carries a secondary registration identifier, where the secondary registration identifier is configured to instruct the UE to request to register to the first network through a first third generation partnership project (3 GPP) standard access technology based on the user identity, and maintain a registration state in the second network through a second 3GPP standard access technology based on the user identity; a first registration management, RM, context of the UE in the first network and a second RM context of the UE in the second network are maintained based on the second registration request message.

In one embodiment, the transceiver module 310 is specifically configured to:

In one embodiment, the second network comprises one of:

a home network of the UE;

and the UE accesses the network.

In an exemplary embodiment, the transceiver module 110, the processing module 120, the transceiver module 210, the transceiver module 310, etc. may be implemented by one or more central processing units (CPU, central Processing Unit), graphics processors (GPU, graphics Processing Unit), baseband processors (BP, baseband Processor), application specific integrated circuits (ASIC, application Specific Integrated Circuit), DSPs, programmable logic devices (PLD, programmable Logic Device), complex programmable logic devices (CPLD, complex Programmable Logic Device), field programmable gate arrays (FPGA, field-Programmable Gate Array), general purpose processors, controllers, microcontrollers (MCU, micro Controller Unit), microprocessors (Microprocessor), or other electronic components for performing the aforementioned methods.

Fig. 10 is a block diagram illustrating an apparatus 3000 for network access according to an example embodiment. For example, apparatus 3000 may be a mobile phone, computer, digital broadcast terminal, messaging device, game console, tablet device, medical device, fitness device, personal digital assistant, or the like.

Referring to fig. 10, the apparatus 3000 may include one or more of the following components: a processing component 3002, a memory 3004, a power component 3006, a multimedia component 3008, an audio component 3010, an input/output (I/O) interface 3012, a sensor component 3014, and a communication component 3016.

The processing component 3002 generally controls overall operations of the device 3000, such as operations associated with display, phone calls, data communications, camera operations, and recording operations. The processing assembly 3002 may include one or more processors 3020 to execute instructions to perform all or part of the steps of the methods described above. Further, the processing component 3002 may include one or more modules to facilitate interactions between the processing component 3002 and other components. For example, the processing component 3002 may include a multimedia module to facilitate interaction between the multimedia component 3008 and the processing component 3002.

The memory 3004 is configured to store various types of data to support operations at the apparatus 3000. Examples of such data include instructions for any application or method operating on device 3000, contact data, phonebook data, messages, pictures, video, and the like. The memory 3004 may be implemented by any type or combination of volatile or non-volatile memory devices, such as Static Random Access Memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic or optical disk.

The power supply assembly 3006 provides power to the various components of the device 3000. The power supply components 3006 may include a power management system, one or more power supplies, and other components associated with generating, managing, and distributing power for the device 3000.

The multimedia component 3008 includes a screen between the device 3000 and the user that provides an output interface. In some embodiments, the screen may include a Liquid Crystal Display (LCD) and a Touch Panel (TP). If the screen includes a touch panel, the screen may be implemented as a touch screen to receive input signals from a user. The touch panel includes one or more touch sensors to sense touches, swipes, and gestures on the touch panel. The touch sensor may sense not only the boundary of a touch or sliding action, but also the duration and pressure associated with the touch or sliding operation. In some embodiments, the multimedia assembly 3008 includes a front camera and/or a rear camera. When the apparatus 3000 is in an operation mode, such as a photographing mode or a video mode, the front camera and/or the rear camera may receive external multimedia data. Each front camera and rear camera may be a fixed optical lens system or have focal length and optical zoom capabilities.

The audio component 3010 is configured to output and/or input audio signals. For example, audio component 3010 includes a Microphone (MIC) configured to receive external audio signals when device 3000 is in an operational mode, such as a call mode, a recording mode, and a speech recognition mode. The received audio signals may be further stored in the memory 3004 or transmitted via the communication component 3016. In some embodiments, the audio component 3010 further comprises a speaker for outputting audio signals.

The I/O interface 3012 provides an interface between the processing component 3002 and a peripheral interface module, which may be a keyboard, click wheel, button, or the like. These buttons may include, but are not limited to: homepage button, volume button, start button, and lock button.

The sensor assembly 3014 includes one or more sensors for providing status assessment of various aspects of the device 3000. For example, sensor assembly 3014 may detect the on/off state of device 3000, the relative positioning of the components, such as the display and keypad of device 3000, sensor assembly 3014 may also detect a change in position of device 3000 or a component of device 3000, the presence or absence of user contact with device 3000, the orientation or acceleration/deceleration of device 3000, and a change in temperature of device 3000. The sensor assembly 3014 may include a proximity sensor configured to detect the presence of nearby objects in the absence of any physical contact. The sensor assembly 3014 may also include a light sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some embodiments, the sensor assembly 3014 may also include an acceleration sensor, a gyroscopic sensor, a magnetic sensor, a pressure sensor, or a temperature sensor.

The communication component 3016 is configured to facilitate wired or wireless communication between the apparatus 3000 and other devices. The device 3000 may access a wireless network based on a communication standard, such as Wi-Fi, 2G, or 3G, or a combination thereof. In one exemplary embodiment, the communication component 3016 receives broadcast signals or broadcast-related information from an external broadcast management system via a broadcast channel. In one exemplary embodiment, the communication component 3016 further includes a Near Field Communication (NFC) module to facilitate short range communications. For example, the NFC module may be implemented based on Radio Frequency Identification (RFID) technology, infrared data association (IrDA) technology, ultra Wideband (UWB) technology, bluetooth (BT) technology, and other technologies.

In an exemplary embodiment, the apparatus 3000 may be implemented by one or more Application Specific Integrated Circuits (ASICs), digital Signal Processors (DSPs), digital Signal Processing Devices (DSPDs), programmable Logic Devices (PLDs), field Programmable Gate Arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic elements for executing the methods described above.

In an exemplary embodiment, a non-transitory computer readable storage medium is also provided, such as memory 3004, including instructions executable by processor 3020 of apparatus 3000 to perform the above-described methods. For example, the non-transitory computer readable storage medium may be ROM, random Access Memory (RAM), CD-ROM, magnetic tape, floppy disk, optical data storage device, etc.

Other implementations of the examples of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of embodiments of the invention following, in general, the principles of the embodiments of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the embodiments of the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the embodiments being indicated by the following claims.

It is to be understood that the embodiments of the invention are not limited to the precise arrangements and instrumentalities shown in the drawings, which have been described above, and that various modifications and changes may be made without departing from the scope thereof. The scope of embodiments of the invention is limited only by the appended claims.

Claims

A network access method, wherein the method is performed by a user equipment UE, comprising:

and accessing a first network through a first third generation partnership project (3 GPP) standard access technology based on the user identity, wherein the UE accesses a second network through a second 3GPP standard access technology based on at least the user identity, and wherein the first network is different from the second network.
The method of claim 1, wherein the accessing the first network via the first 3GPP standard access technology comprises:

and registering the first network through the first 3GPP standard access technology, wherein the UE is registered with the second network through the second 3GPP standard access technology at least based on the user identity.
The method of claim 2, wherein the registering the first network with the first 3GPP standard access technology comprises:

sending a first registration request message requesting to register to the first network to an AMF of the first network through the first 3GPP standard access technology, wherein the first registration request message carries a secondary registration identifier, the secondary registration identifier is used for indicating that the UE requests to register to the first network through the first 3GPP standard access technology based on the user identity, and the UE is in a registration state in the second network through the second 3GPP standard access technology based on the user identity.
The method of claim 3, wherein the method further comprises,

receiving a registration acceptance message sent by the access and mobility management function (AMF) based on the first registration request message and indicating successful registration to the first network;

The registration acceptance message is sent by the AMF through a second registration request message to register the registration information of the UE to a unified data management function UDM of a home network of the UE, and based on receiving a registration response message of the UDM, wherein the second registration request message carries the secondary registration identifier.
The method of claim 4, wherein the registration response message is sent by the UDM to determine to maintain a first registration management, RM, context for the UE in the first network and a second RM context for the UE in the second network based on the second registration request message.
The method of any one of claims 1 to 5, wherein the method further comprises: a first RM context of the UE in the first network and a second RM context of the UE in the second network are maintained.
The method of any of claims 1 to 5, wherein the second network comprises one of:

a home network of the UE;

and the UE accesses the network.
The method according to any one of claims 1 to 5, wherein,

the first network is determined by the UE based on a network identifier in a downlink instruction;

And/or the number of the groups of groups,

the first network is detected by the UE.
A network access method, wherein execution of an access and mobility management function, AMF, by a first network, comprises:

determining service parameters for User Equipment (UE), wherein the service parameters are service parameters of the UE accessing a first network through a first 3GPP standard access technology based on a user identity, wherein the UE accesses a second network through a second 3GPP standard access technology based on at least the user identity, and wherein the first network is different from the second network.
The method of claim 9, wherein the determining service parameters for the UE comprises:

and determining service parameters for the UE to register to the first network through the first 3GPP standard access technology based on the user identity, wherein the UE is registered to the second network through the second 3GPP standard access technology based at least on the user identity.
The method of claim 10, wherein the determining service parameters for the UE to register with the first network over the first 3GPP standard access technology based on the user identity comprises:

Receiving a first registration request message sent by the UE based on the user identity and requesting to register to the first network, wherein the first registration request message carries a secondary registration identifier, the secondary registration identifier is used for indicating that the UE requests to register to the first network through the first 3GPP standard access technology based on the user identity, and the UE is in a registration state in the second network through the second 3GPP standard access technology based on the user identity.
The method of claim 11, wherein the determining service parameters for the UE to register with the first network over the first 3GPP standard access technology based on the user identity comprises:

transmitting a second registration request message for registering registration information of the UE to a UDM of a home network of the UE based on the first registration request message; the second registration request message carries an indication of the secondary registration identifier;

and receiving a registration response message sent by the UDM based on the second registration request message.
The method of claim 12, wherein the registration response message is sent by the UDM to determine to maintain a first registration management, RM, context for the UE in the first network and a second RM context for the UE in the second network based on the second registration request message.
The method of claim 12, wherein the determining service parameters for the UE to register with the first network over the first 3GPP standard access technology based on the user identity comprises:

and when receiving the registration response message, sending a registration acceptance message indicating that the registration to the first network is successful to the UE.
The method of any of claims 9 to 14, wherein the second network comprises one of:

a home network of the UE;

and the UE accesses the network.
A network access method, wherein the execution of a unified data management function, UDM, by a home network, comprises:

receiving a second registration request message sent by an access and mobility management function (AMF) of a first network, wherein the second registration request message is used for indicating that registration information of User Equipment (UE) is registered to the UDM, wherein the second registration request message carries a secondary registration identifier, wherein the secondary registration identifier is used for indicating that the UE requests to register to the first network through a first third generation partnership project (3 GPP) standard access technology based on the user identity, and maintaining a registration state in the second network through a second 3GPP standard access technology based on the user identity;

A first registration management, RM, context of the UE in the first network and a second RM context of the UE in the second network are maintained based on the second registration request message.
The method of claim 16, wherein,

the second registration request message is sent by the AMF after receiving a first registration request message, where the first registration request message is sent to the AMF by the UE through the first 3GPP standard access technology based on the user identity, and the first registration request message carries the second registration identity.
The method of claim 17, wherein the method further comprises:

determining to maintain the first RM context and the second RM context, and sending a registration response message to the AMF.
The method of any of claims 16-18, wherein the second network comprises one of:

a home network of the UE;

and the UE accesses the network.
A network access device is arranged in User Equipment (UE); wherein, include:

and the receiving and transmitting module is configured to access a first network through a first third generation partnership project (3 GPP) standard access technology based on a user identity, wherein the UE accesses a second network through a second 3GPP standard access technology based on at least the user identity, and the first network is different from the second network.
A network access device is arranged in an AMF of a first network of User Equipment (UE); wherein, include:

and the receiving and transmitting module is configured to determine service parameters for User Equipment (UE) to access a first network through a first 3GPP standard access technology based on a user identity, wherein the UE accesses a second network through a second 3GPP standard access technology based at least on the user identity, and the first network is different from the second network.
A network access device is arranged in a UDM of a home network of User Equipment (UE); wherein, include:

a transceiver module configured to receive a second registration request message sent by an access and mobility management function AMF of a first network, where the second registration request message is configured to instruct to register registration information of a user equipment UE to the UDM, where the second registration request message carries a secondary registration identifier, where the secondary registration identifier is configured to instruct the UE to request to register to the first network through a first third generation partnership project (3 GPP) standard access technology based on the user identity, and maintain a registration state in the second network through a second 3GPP standard access technology based on the user identity; a first registration management, RM, context of the UE in the first network and a second RM context of the UE in the second network are maintained based on the second registration request message.
A communications device apparatus comprising a processor, a memory and an executable program stored on the memory and executable by the processor, wherein the processor performs the steps of the network access method of any one of claims 1 to 8, or 9 to 15, or 16 to 21 when the executable program is run by the processor.
A storage medium having stored thereon an executable program, wherein the executable program when executed by a processor performs the steps of the network access method of any of claims 1 to 8, or 9 to 15, or 16 to 19.