Patent Application
20050288016
The present disclosure relates generally to communications networks, and more particularly to communications between wireless communications devices and wireless communications networks having divided into logical portions, for example, multiple location areas, messages and methods.
Public Land Mobile Network (PLMN) wireless communications networks generally comprise one or more location areas, which are defined arbitrarily by the network operator. A location area (LA) generally comprises a plurality of cells controlled by a Base Station Controller (BSC) which itself is within a Mobile Switching Center (MSC) service area in the PLMN.
Wireless communications network operators generally control network access on a Public Land Mobile Network (PLMN) or a Location Area (LA) basis or both. 3GPP TS 22.011, 23.122 and 24.008 describe network registration procedures and TS 24.008 describes the procedure for the network to reject mobile stations on an individual location area basis during a registration attempt. For example, the network can send the mobile station a registration rejection requiring the mobile station to search for another suitable cell in a different location area within the same PLMN.
Typically any new communications network is rolled out in a phased manner. For example, the rollout of 3rd Generation (3G) wireless communications networks is being performed in a phased manner that will create islands of 3G service areas in a sea of 2G networks. Meanwhile, 3G network operators will provide access to 2G networks until 3G networks are deployed in all areas. While many network operators rolling out newer 3G network services have already deployed 2G networks, other 3G network operators do not have 2G spectrum licenses.
3G network operators without 2G licenses must rely on roaming agreements with 2G network operators in order to provide contiguous service for subscribers. A 2G/3G network operator having a roaming agreement to provide service to subscribers of 3G only operators however will want to exclude the 3G only operators' subscribers from using the 3G portion of its network.
The 3GPP specifications recognize the concept of Equivalent PLMNs, whereby a mobile terminal is provided an indication of which PLMNs are to be considered as equivalent for the purpose of network registration. Mobile terminals receive the equivalent PLMN list on successful completion of the location update procedures. However, if the PLMN identity of both the 3G and 2G networks of the same operator are identical, then a roaming mobile terminal cannot be sent a location update reject indicating that the PLMN is forbidden, since the 2G network would also then become forbidden to the roaming subscriber.
The various aspects, features and advantages of the disclosure will become more fully apparent to those having ordinary skill in the art upon careful consideration of the following Detailed Description thereof with the accompanying drawings described below.
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Generally, the communications system or PLMN may comprise multiple core network entities each of which is coupled to multiple radio access networks. In some communications systems or PLMNS, multiple core network entities share the same radio access network or networks and its corresponding radio spectrum. For example, different service providers may operate different core networks identified by corresponding core network identities, for example, by a corresponding Public Land Mobile Network (PLMN) identity (ID), sharing one or more common access networks.
As technology advances, it is common for communications networks to support different communications technologies or protocols, wherein newer generation technologies are compatible with older legacy technologies. In
Wireless communications systems are often divided into multiple smaller location areas defined by relatively small operational coverage areas, for example, multiple cellular coverage areas. The network operators are free to define location areas in any desired manner. In one embodiment, the communications technology is one of the criteria used to define location areas. In
In some applications, it may be desirable to limit roaming agreements by or to particular communications technologies. For example, a 3G network operators without a 2G license must rely on roaming agreements with 2G network operators in order to provide contiguous service for its subscribers, since 3G service is not yet fully deployed in all geographic areas. A 2G/3G network operator having a roaming agreement with a 3G only operator however may want to exclude the 3G only operator's subscribers from using the 3G portion of the 2G/3G operator's network.
Consider two wireless communications network operators A and B. Operator A has only 3G networks, and operator B has 2G/3G networks. Operator A would like a roaming agreement for use of the 2G network of operator B. Operator B would however like to prohibit 3G subscribers of operator A from accessing the 3G network of operator B.
Generally, network access may be prohibited to roaming mobile subscriber terminals either on PLMN or location area basis using the registration procedure. Particularly, when a terminal attempts to register on a PLMN, the terminal may either be accepted or rejected with a cause value. Some cause values allow the entire PLMN to be indicated as forbidden and so stored on the communications device, for example, in a subscriber identification module (SIM). In some embodiments, a mobile subscriber may have a regional subscription and may therefore have restricted access privileges to different location areas of a PLMN, i.e., certain location areas can be forbidden whereas other are not. A network operator having both 2G and 3G networks may preclude roaming on its 3G networks by defining location areas based on technology, as discussed above. If a roaming mobile terminal attempts to register in a forbidden location area, e.g., some or all 3G location areas of operator B, the network of operator B may reject the registration attempt by sending a registration reject message. The roaming mobile will then select another location area and again attempt registration. However, the registration attempt will be rejected again if roaming mobile selects another forbidden location area. In some applications, the additional signaling associated with failed register attempts is undesirable.
In some embodiments, an equivalent list of location area identities can be provided to the mobile individually identifying each and every prohibited location area. The list may identify only prohibited location areas or permissible location areas. The 3GPP specifications recognize the concept of Equivalent PLMNs, whereby a mobile terminal is provided an indication of which PLMNs are to be considered as equivalent for the purpose of registration. The equivalent list concept can be extended in the specifications to apply to location areas as well, through individual listing of all the permitted or prohibited location areas. In some applications, however, long lists identifying permitted or prohibited location areas may unduly increase the size of the message, for example, the registration reject message that transports the list. Thus in some embodiments, it may be desirable for the message from the network to identify a range of permitted or prohibited location areas, thereby reducing the message size and speeding up the process of successful registration.
In one embodiment, a mobile communications device sends a communication to a communications network, and in response the communications device receives from the network a message including information identifying at least one of a network portion to which the wireless communications device is prohibited from attaching, or a network portion to which the wireless communications device is permitted to attach.
In the exemplary communications diagram 300 of
In embodiments where the mobile station or terminal 310 attempts to connect or attach to the network, generally, the terminal sends a connection or attachment request, which may include the identity of the device, e.g., an MSID, location area information. A communications specification specifies the protocol, criteria and procedures for connecting to any particular network.
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In one embodiment, the message received from the network includes information identifying one or more network location areas to which the wireless communications device is prohibited from attaching. In the exemplary roaming agreement between a 3G only network operator and a 2G/3G network operator, the prohibited location areas could be those supported by 3G communications technology in the 2G/3G operator's network. In another embodiment, the message received from the network includes identifies a range of location areas where the wireless communications device is prohibited from attaching. In some embodiments, upon receiving information identifying portions of the network to which the terminal is prohibited from attaching, the terminal does not attempt to attach or register in the portions of the network identified in the message, thereby reducing network traffic that would otherwise result from unsuccessful attempts to attach to the network. In other embodiments, upon receiving information identifying portions of the network to which the terminal is allowed attaching, the terminal attempts to attach or register only in the portions of the network identified in the message, thereby reducing network traffic that would otherwise result from unsuccessful attempts to attach to the network.
In one embodiment, when the network receives an attachment request from the terminal, the network identifies any portions of the communications network where terminal operable within the communications network is or is not permitted to attach or register. In
While the present disclosure and what are presently considered to be the best modes thereof have been described in a manner establishing possession by the inventors and enabling those of ordinary skill in the art to make and use the same, it will be understood and appreciated that there are many equivalents to the exemplary embodiments disclosed herein and that modifications and variations may be made thereto without departing from the scope and spirit of the inventions, which are to be limited not by the exemplary embodiments but by the appended claims.
