CN1703918A - Network selection in a WLAN - Google Patents

Abstract

A method for a user equipment (UE) residing within a wireless access network (WLAN) to gain access to at least one other network. The method comprises: storing in the user equipment the identification (SSID) of the at least one other network (visited PLMNs 1-3 and home PLMNs 4 and 5); a request for a connection to the radio access network, the request including an identification of at least one of the at least one other network; and in response to the radio access network receiving the identification, the user equipment via the radio access network The inbound network is connected to said identified at least one other network.

Description

Network Selection in WLAN

technical field

The present application relates to a system and method for network selection by a user equipment (UE) within an access network such as a wireless local area network (WLAN).

Background technique

In the WLAN specification (IEEE 802.11a and b, the full text of which is hereby incorporated by reference), the WLAN can inform the UE of the Service Set Identifiers (SSIDs) of the networks to which it can connect (32 octets in length) . Usually in a WLAN system, the WLAN SSID field includes a "network name". The network name is an ASCII character string freely selectable by the WLAN provider. It is usually a string like "WLAN NW XYZ" or "Mr SmithWLAN" or "NOKIA WLAN". These types of names are used manually by the user to select the network to connect to. However this requires a priori knowledge about the capabilities of the network with a certain name. This type of use is acceptable for private networks where users usually always connect them to a small number of WLAN networks.

However, it is impossible for users to have a complete understanding of all WLAN network names (SSIDs) and their capabilities. Therefore, the user does not have the option to choose the best network, or even have a viable option to choose from the list of network names provided.

In cellular systems, network selection is handled by cellular networks broadcasting their Public Land Mobile (PLMN) Identification (ID). The UE may perform automatic network selection based on preferences made by the operator or user stored in the GSM Subscriber Identity Module (SIM) or Universal Subscriber Identity Module (USIM). The UE allows the user to manually select when browsing available PLMNs. The UE converts the PLMN to a user-friendly network name from internal memory, and the user selects the desired network.

In GSM and GPRS systems, the PLMN-ID is linked to a branded network based on information stored in the UE.

Contents of the invention

The present invention provides a mechanism for a UE residing in an access network such as a WLAN to choose to connect to another network through the access network. This selection operates as follows:

1. WLAN Access Points (APs) broadcast SSIDs to provide UEs with indications of available backbone networks (eg, national PLMNs) accessible via WLAN Access Zones (AZs).

2. The UE can manually or automatically select an access network through user intervention. Automatic selection based on signal strength and availability of preferred PLMN or other preferred backbone.

3. The UE selects a backbone network based on available SSIDs. SSIDs containing PLMN-IDs can be linked to tagged networks based on information stored in the WLAN UE client software.

4. When connecting to a network, the UE indicates the selected roaming network (eg PLMN) in the realm part of the Network Access Identifier (NAI) user identity sent to that network.

5. The WLAN access network establishes routing of the connection to the backbone network (eg visited PLMN) based on the attached NAI user ID field part derived from the selected SSID.

A method for a user equipment residing in a radio access network to gain access to at least one other network, comprising: storing in the user equipment an identity of the at least one other network; sending from the user equipment a a request to the radio access network for connection with one of the at least one other network, the request including an identification of at least one of the at least one other network; and in response to the radio access network receiving The identification, the user equipment is connected to the identified at least one other network through the radio access network. In the request to connect to one of the at least one network, the identification of the at least one of the at least one other network or network type may include a wildcard character representing a variety of other networks or network types that may be selected. combination of licenses. The identity of the at least one other network may be sent from the radio access network to the user equipment before being stored. The at least one other network may be a home network or a roaming network. The user equipment solicits the identity of the at least one network from the radio access network before requesting connection with one of the at least one network. The identification of the at least one other network may be included in a service set identifier according to IEEE 802.11(a or b), which identifies the at least one other network as a Public Land Mobile Network. The service set identifier may include a plurality of fields, including a field identifying a network type, where the network type is a public land mobile network; a field identifying a country code, where the at least one public land mobile network is located; and identifying the A field of at least one public land mobile network to which the connection request is to be routed. The identification of the at least one network may be included in a service set identifier according to IEEE 802.11 (a or b), which identifies the at least one other network as a network type other than the public land mobile network, and the service set identifier may be A plurality of fields are included, including a field defining a network type of the at least one other network, and a field identifying the at least one other network.

According to another aspect of the present invention, there is provided a method for a UE to gain access to at least one other network via an access network, the at least one other network being accessible via the access network, the method comprising: providing At least one access network identifier related to the access network and the at least one other network; and the UE deduces the identifier of the at least one other network according to the at least one access network identifier. The user equipment may utilize the at least one access network identity when establishing a connection with the at least one other network. The access network may route the UE's connection to at least one other network associated with the at least one access network identity. At least one access network identity may be sent from the access network to the UE when connecting the UE to the access network. Before the connection, the UE may acquire at least one access network identifier utilized by the access network, and the access network identifier may include at least one field. The at least one other network may be a Public Land Mobile Network (PLMN). The at least one other network may be a roaming PLMN network connected to the home PLMN network. The access network may be a WLAN. The access network identity may be included in a service set identifier according to IEEE 802.11 (a or b). The access network identity may be mapped to a PLMN ID of said at least one other network.

According to another embodiment of the present invention there is provided a service set identifier delivered in an access network comprising at least one identifier of a backbone network. The service set identifier includes an indication of the backbone network type, a version number of the service set identifier type, and an identifier of the backbone network. In the case that the backbone network is a PLMN, the identifier of the backbone network includes a country code corresponding to the country where the backbone network is located, and a network code identifying the backbone network. In addition, the access network is WLAN.

The service set identifier delivered in the access network according to the invention comprises an embedded identification for the backbone network connected to the access network. The business set identifier may follow a predetermined structure. When the backbone network is a public land mobile network, the identifier of the backbone network includes the country code corresponding to the country where the backbone network is located, and the network code identifying the backbone network. The access network may be a wireless local area network.

A system according to the invention comprises a radio access network; at least one other network accessible via the radio access network, and a user equipment residing on said radio access network; wherein an identity of said at least one other network is stored In the user equipment, a request for connection to one of the at least one other network (including an identification of at least one of the at least one other network) is sent from the user equipment to the radio access network, and in response to the The identification is received by a radio access network through which the user equipment is connected to at least one other network identified. The identity of the at least one other network may be sent from the radio access network to the user equipment before being stored. The user equipment may solicit the identity of the at least one network from the radio access network before requesting a connection with one of the at least one other network. The at least one other network may be a home network or a roaming network. The service set identifier may include a plurality of fields, including a field identifying a network type, identifying the network type as a public land mobile network; a field identifying a country code, in which the at least one public land mobile network is located, and identifying the A field of at least one public land mobile network to which the connection request is to be routed. The identifier of the at least one network may be included in a service set identifier according to part a or b of IEEE 802.11, which identifies the at least one other network as a network type other than the public land mobile network, and the service set identifier may A plurality of fields are included, including a field defining a network type of the at least one other network, and a field identifying the at least one other network.

The system according to the invention comprises: a radio access network, at least one other network accessible via said radio access network, a user equipment, wherein at least one interface of said access network related to said at least one other network is provided a network access identifier; and the UE deduces the identifier of the at least one other network according to the at least one access network identifier. The user equipment may utilize at least one access network identity when establishing a connection with the at least one other network. The access network may route the UE's connection to at least one other network associated with the at least one access network identity. At least one access network identity may be sent from the access network to the UE before connecting the UE to the access network. The access network identifier may include at least one field. The at least one other network may be a PLMN network. The at least one other network may be a roaming PLMN network connected to the home PLMN network. The access network may be a WLAN. The access network identity may be included in the service set identifier according to IEEE 802.11 part a or b. The access network identity may be mapped to a PLMN ID of said at least one other network.

Description of drawings

Figure 1 illustrates an exemplary system in which the invention may be practiced, including the relationship of SSIDs depending on the proper state of roaming, interworking and sharing relationships.

Detailed ways

Referring to Figure 1, network selection involves the following two parts:

●WLAN access area selection

● Visited network (eg, PLMN) selection

The selection of WLAN network access area can be performed as follows:

The UE always tries to first connect directly to the home network, which is the home PLMN 4, which includes the UE's Home Location Register (HLR). If the home network is not available, the UE tries to connect via the preferred backbone network. The selection of the backbone network can be automatic, user assisted, user equipment solicited, or manually done by the user of the UE. Communications of SSIDs from visited PLMN1 and 3 to visited PLMN2 are illustrated as arrows SSIDPLMN1 and SSID PLMN2, which are sent to visited PLMN2. The visited PLMN2 sends the SSIDs of the visited PLMN1 and PLMN2 to the WLAN access area. Moreover, the SSID identity of PLMN3 is directly passed to the WLAN access zone. The transfer of the SSID to the WLAN access zone can be done directly. Each of the visited PLMNs 1-3 and the home PLMN 5 has an access stratum AS.

Information about the available backbone networks is passed to the UE by the WLAN AP in the form of the WLAN SSID.

The UE can map each SSID to the backbone network. The UE can then choose which of the available backbone networks it wishes to connect to. [The selection can be automatic, user assisted or manually done by the user. ] After selection, the UE associates with the access network, such as visited PLMN2, using the SSID corresponding to the selected backbone network.

The SSID can use "wildcards" in the specification of country and/or network type. A wildcard means selecting any network with a characteristic from a set of characteristics, such as a set of countries of a particular type or a set of countries or network types within a set of networks. For example, the designation could be "any type 1 PLMN in Finland", where the PLMN type and country code are fixed, but the mobile network code is replaced by a wildcard, which designates any mobile network. In text form, "wildcards" can be various characters, such as "?", "+" or "*", which have a negotiated wildcard-designated meaning, enabling their use in place of networks with characteristic-indicating characteristics, such as countries and/or network type designations indicate any country and/or any network within a set of networks of a particular type that may be used in a particular country. For example, the country code can be replaced with a wildcard to indicate that this SSID represents "any Orange PLMN" in any country.

The access network (visited PLMN2 illustrated) further routes the connection to the correct backbone, eg visited PLMN1 or home PLMNs 4 or 5, based on the selected SSID. For example, for each SSID associated with the backbone network, tunneling technology can be used to transmit all data between the access network and the backbone network. Therefore, the routing to and from the backbone network can be thought of as tunnel mapping. The tunnel can be, for example, a GRE tunnel, a virtual LAN, L2TP, a dedicated layer-3 connection or any other similar transport mechanism.

In another exemplary embodiment, each SSID associated with the backbone network may be automatically transformed into an Authentication, Authorization, and Accounting (AAA) realm name, such as a Remote Authentication Dial-In (RADIUS) realm name in a user server, Or point to the DIAMETER domain name of the AAA server in the backbone network. The domain name entity exists in the visited PLMNs 1-3 and the home PLMN5 acts as an AAA proxy. In the following examples, RADIUS is used as the example AAA method.

When the UE selects an SSID, the UE creates a RADIUS realm from the selected SSID and adds this realm to the end of the user identity in Network Access Identifier (NAI) format. Since the linked user identity conforms to the NAI format, the authentication is first routed to the selected backbone network. The backbone network strips the link part from the original NAI and forwards the signaling further to at least one additional network to which the UE wishes to connect, such as a connection from visited PLMN2 to visited PLMN1 and one of the home PLMNs 4 or 5.

1. Use of identifiers

A. Set the SSID value

1. SSID for PLMN backbone network:

If the PLMN is the backbone network for the WLAN access area, the SSID pointing to this PLMN may, for example, follow the following format:

[reserved words for network SSIDs of type PLMN][version number][MCC][MNC][free text]

in

● Reserved words for network SSIDs of type PLMN to distinguish this type of SSID from other SSIDs

● Version numbers enable future format changes

●Mobile country code (MCC) is PLMN country code

●Mobile Network Code (MNC) is PLMN Network Code

● Free text can be used, for example, to indicate user-friendly network names

The actual content of the SSID field can vary from what is suggested above, and what is indicated is only intended as an example of how to implement the SSID field configuration.

2. SSID for non-PLMN backbone network:

If the backbone network is not a PLMN, the SSID pointing to the network can be in the following format:

[Reserved words for non-PLMN type network SSIDs][version number][network name]

in

● Reserved words for non-PLMN type network SSIDs to distinguish this type of SSID from other SSIDs

● Version numbers enable future format changes

●The network name is the name of the backbone network

The actual content of the SSID information field can vary, and what is indicated is intended only as an example of how to implement the configuration of the SSID field, without any limitation.

II. SSID configuration

A. National WLAN roaming between backbone networks

If the backbone has a national roaming agreement with another backbone that is not directly connected to the same WLAN AZ, then:

●The provider of the backbone network that is not connected can provide its SSID for the provider of the connected backbone network

• The connected backbone network can modify its SSID and the received SSID of any national roaming partner network roaming to the WLAN Access Zone (AZ).

WLAN AP can store all supported SSIDs in the SSID list in WLAN AP.

B. Shared WLAN Access Zone:

A shared WLAN AZ may include all SSIDs offered by all backbones with which the WLAN AZ provider has an interconnection agreement to provide WLAN access services.

WLAN AP can store all supported SSIDs in the SSID list in WLAN AP.

The SSID information may be delivered to the UE as follows:

In 802.11b beacon frames, the WLAN UE only receives the beacon SSID. The SSID can be in the above format, so it can already be used for the UE's backbone network selection. The UE may also store preferred networks based on the broadcast SSID for facilitating out-of-the-box association with the network.

If the UE supports valid scanning for SSID information, the UE may start scanning for available networks in a preferred order.

First, the UE may scan for its home PLMN SSID. If there is no response from the WLAN AP, the WLAN UE may start scanning for preferred roaming partners. To facilitate guessing available roaming partners, the UE may guess the country it is in.

It is possible to do the following:

The UE may always first assume it is in its home country, thus scanning for the country roaming SSID

●UE can store the most frequently visited countries and use this information for selecting SSIDs to scan

A dual-mode UE can check the attached cellular network and use this information for selecting an SSID to scan

The UE may request the user to indicate which country the WLAN UE is located in

●UE can randomly start scanning for available SSIDs

WLAN UEs can also use wildcards when searching for an appropriate SSID. For example, the WLAN UE may request the availability of an SSID comprising a specific string followed by any string. The WLAN UE may also request the WLAN AP to indicate all supported SSIDs.

Select a WLAN Access Network (AN)

UE may select WLAN AN based on signal strength and based on availability of home PLMN or preferred backbone roaming network SSID.

The home network PLMN ID can be derived from the subscriber's International Mobile Subscriber Identity (IMSI) obtained from the SIM or USIM.

To select a preferred roaming PLMN, a preferred list of PLMNs stored in the SIM or USIM can be used.

Select backbone and store by UE

UEs that support network selection can implement automatic and/or manual selection of roaming networks. The identity of the roaming network may be sent from the radio access network to the UE for storage, and may be in response to a request by the user equipment to identify the roaming network. The identification of the roaming network may be included in the service set identifier according to parts a and b of IEEE802.11.

User ID NAI domain part set by UE

Before sending an Extensible Authentication Protocol (EAP) Identity Response, the UE may select a backbone network to connect to.

If the UE does not support this feature, the UE uses its home network realm, and depending on the implementation, to determine RADIUS routing towards the identity of the home PLMN AAA proxy server.

If the WLAN UE supports network selection for roaming, the UE can select which available backbone network the WLAN AN can direct the user to. The results of this selection can be displayed in the Exploited Domains section as follows:

Not the original user ID assigned by the home network:

〔userid〕@〔homeASrealm〕,

The UE may utilize the following User IDs in the EAP Identity Response:

〔userid〕@〔homeASrealm〕.[Selected backbone network SSID].〔OWLAN.ORG〕

RADIUS Routing by Network Radius Proxy

RADIUS proxies receiving the above user NAI check from their "RADIUS Routing Tables" whether the message is forwarded. The routing is based on the "most significant bit" of the field, ie, according to the inserted [Selected Backbone SSID].[OWLAN.ORG] section.

When a RADIUS access request arrives at the RADIUS server identified by the [chosen backbone SSID].[OWLAN.ORG] realm, the RADIUS server strips off the inserted portion and performs authentication of the user based on the remaining NAI.

Alternatively, the UE can choose independently of the backbone network, always using its home network NAI as its user identity. In this case, the WLAN UE indicates the selected SSID when connecting to this access network. The access network then routes the connection further to the backbone network associated with the utilized SSID. This could, for example, be accompanied by pre-configured tunnels between the access network and each backbone network.

User authentication to be performed may still involve AAA roaming (proxy) or Mobile Application Part (MAP) roaming to the user's home network. However this further roaming is not affected by the new PLMN selection feature.

The present invention provides a mechanism of how to provide a UE with a PLMN-ID (identifying a mobile operator network) by using the SSID field.

When the PLMN ID is included in the SSID field, the cellular network selects a public WLAN network that may be used for interconnection with the cellular system. This enables global scalability and automatic network selection for WLANs.

With the present invention, the PLMN ID is included in the SSID field, allowing identification by accessing the UE's PLMN ID information for the UE or its user's network selection.

If the UE contains the selected SSID with EAP signaling between the UE and the home network, the home network has the ability to check if the WLAN AZ and the roaming partner have followed the UE network selection and have not routed the connection to the network, e.g. for Roaming partners give the highest roaming charges. The home network can compare the PLMNID derived from the UE inserted SSID with the origin of the received authentication request, if there is no match, the WLAN access network or roaming partner is determined not to be functioning correctly.

Claims (46)

1. one kind is used to reside in the method that the interior subscriber equipment of wireless access network is inserted at least one other network, comprising:

The sign of described at least one other network of storage in subscriber equipment;

From subscriber equipment send one with one of described at least one other network connection requests to described wireless access network, described request comprises at least one the sign in described at least one other network; And

Receive described sign in response to described wireless access network, subscriber equipment is connected at least one other network of described sign by described wireless access network.

2. according to the process of claim 1 wherein:

The storage that is identified at of described at least one other network is sent to subscriber equipment from wireless access network before.

3. according to the method for claim 1-2, wherein:

Subscriber equipment is in request and the sign of imploring described at least one network before one of described at least one other network are connected from described wireless access network.

4. according to the method for claim 1-3, wherein:

Described at least one other network are home network.

5. according to the method for claim 1-3, wherein:

Described at least one other network are roaming networks.

6. according to the method for claim 1-5, wherein:

The sign of described at least one other network is included in the services sets identifier according to IEEE 802.11 (a or b), and described at least one other network of its sign are public land mobile net.

7. according to the method for claim 6, wherein:

Described services sets identifier comprises a plurality of fields, wherein comprises the field of marked network type, and identifying described network type is public land mobile net; The field of sign country code, described at least one public land mobile net is positioned at described country; And the field that identifies at least one public land mobile net that described connection request will be routed to.

8. according to the method for claim 1-5, wherein:

The sign of described at least one network is included in the services sets identifier according to IEEE 802.11 (a or b), and described at least one other network of its sign are the network type beyond the public land mobile net.

9. method according to Claim 8, wherein:

Described services sets identifier comprises a plurality of fields, wherein comprises the field that limits described at least one other network of network type, and the field that identifies described at least one other network.

10. one kind is used for UE and is inserted the method for at least one other network via Access Network, and described at least one other network can insert via described Access Network, and described method comprises:

Provide described Access Network at least one Access Network sign relevant with described at least one other network; And

UE derives the sign of described at least one other network according to described at least one Access Network sign.

11. according to the method for claim 10, wherein:

Described subscriber equipment uses at least one Access Network to identify when setting up with being connected of described at least one other network.

12. according to the method for claim 10-11, wherein:

Described Access Network is routed to the connection of described UE and at least one relevant other network of described at least one Access Network sign.

13. according to the method for claim 10-12, wherein:

Before UE was connected to Access Network, at least one Access Network sign was sent to UE from Access Network.

14. according to the method for claim 13, wherein:

Before UE was connected to Access Network, UE obtained at least one Access Network sign that described Access Network utilizes.

15. according to the method for claim 14, wherein:

Described Access Network sign comprises at least one field.

16. according to the method for claim 10-15, wherein:

Described at least one other network are PLMN networks.

17. according to the method for claim 10-15, wherein:

Described at least one other network are the roaming PLMN networks that link to each other with the Home PLMN network.

18. according to the method for claim 10-15, wherein:

Described Access Network is WLAN.

19. according to the method for claim 10-18, wherein:

Described Access Network identifies among a or b services sets identifier partly that is included in according to IEEE 802.11.

20. according to the method for claim 10-19, wherein:

Described Access Network sign is mapped to the PLMN ID of described at least one other network.

21. a services sets identifier transmits in the Access Network of at least one identifier that comprises backbone network, described services sets identifier comprises:

The indication of backbone network type,

The version number of services sets type of identifier, and

The sign of backbone network.

22. according to the services sets identifier of claim 21, wherein:

When backbone network was public land mobile net, the sign of backbone network comprised the pairing country code of the residing country of described backbone network, and the network code that identifies described backbone network.

23. according to the services sets identifier of claim 21-22, wherein:

Described Access Network is a wireless lan (wlan).

24. a services sets identifier that transmits in Access Network comprises:

The sign that is used for the embedding of the backbone network that is connected with Access Network.

25. according to the services sets identifier of claim 24, wherein:

Described services sets identifier is followed predetermined structure.

26. according to the services sets identifier of claim 24-25, wherein:

At backbone network is under the situation of public land mobile net, and the sign of backbone network comprises the pairing country code of the residing country of described backbone network, and the network code that identifies described backbone network.

27. according to the services sets identifier of claim 24-26, wherein:

Described Access Network is a wireless lan (wlan).

28. according to the method for claim 3, wherein:

The described imploring asterisk wildcard that comprises is as the part of the sign of described at least one other network or network type.

29. a system comprises:

Wireless access network;

At least one other network that can insert via described wireless access network, and

Reside in the subscriber equipment of described wireless access network; And wherein

The sign of described at least one other network is stored among the subscriber equipment, be used for being sent to wireless access network from subscriber equipment with one of described at least one other network connection requests, described request comprises at least one sign of described at least one other network, and receiving described sign in response to described wireless access network, described subscriber equipment is connected at least one other network of described sign by described wireless access network.

30. according to the system of claim 29, wherein:

Being identified at before the storage of described at least one other network is sent to described subscriber equipment from described wireless access network.

31. according to the system of claim 29-30, wherein:

Subscriber equipment is in request and the sign of imploring described at least one network before one of described at least one other network are connected from described wireless access network.

32. according to the system of claim 29-31, wherein:

Described at least one other network are home network

33. according to the system of claim 29-31, wherein:

Described at least one other network are roaming network.

34. the system according to claim 33 comprises:

The services sets identifier, described services sets identifier comprises a plurality of fields, the field that wherein comprises the marked network type, identifying described network type is public land mobile net, the field of sign country code, described at least one public land mobile net is positioned at described country, and the field that identifies at least one public land mobile net that described connection request will be routed to.

35. according to the system of claim 34, wherein:

The sign of described at least one network is included in according in a of IEEE 802.11 or the b services sets identifier partly, and described at least one other network of its sign are the network type beyond the public land mobile net.

36. according to the system of claim 35, wherein:

Described services sets identifier comprises a plurality of fields, wherein comprises the field that limits described at least one other network of network type, and the field that identifies described at least one other network.

37. a system comprises:

Wireless access network;

At least one other network that can insert via described wireless access network;

Subscriber equipment; And wherein

Provide described Access Network at least one Access Network sign relevant with described at least one other network; And UE derives the sign of described at least one other network according to described at least one Access Network sign.

38. according to the system of claim 37, wherein:

Described subscriber equipment uses at least one Access Network to identify when setting up with being connected of described at least one other network.

39. according to the system of claim 37-38, wherein:

Described Access Network is routed to the connection of described UE and at least one relevant other network of described at least one Access Network sign.

40. according to the system of claim 37-39, wherein:

Before UE is connected to described Access Network, transmit at least one Access Network sign from described Access Network.

41. according to the system of claim 37-40, wherein:

Described at least one Access Network sign comprises at least one field.

42. according to the system of claim 37-41, wherein:

Described at least one other network are PLMN networks.

43. according to the system of claim 37-41, wherein:

Described at least one other network are the roaming PLMN networks that are connected with the Home PLMN network.

44. according to the system of claim 37-41, wherein:

Described Access Network is WLAN.

45. according to the system of claim 37-44, wherein:

Described Access Network identifies among a or b services sets identifier partly that is included in according to IEEE 802.11.

46. according to the system of claim 37-41, wherein:

Described Access Network sign is mapped as the PLMN ID of described at least one other network.