Nortel Networks Corporation

Northern Telecom Limited

Jim Xu

Joseph S M Ho

Hakan Ernam

Christopher S Reece

Hua Jiang

Joseph S Ho

Joseph Ho

Julie Y C Liu

Sirin Tekinkay

A method and system for improving overall system capacity in GSM networks by reducing the number of home location register and visitor location register queries is disclosed. The method and system allows the reuse of the MSRN by allocating the MSRN to a mobile terminal and using it for future calls. The method of the present invention allows the GMSC to cache the MSRN for a called mobile terminal. During a first call setup, an entry is recorded at a cache register that maps the Mobile Subscriber ISDN Number (MSISDN) of the mobile terminal to a previously allocated MSRN. Additionally, the Bearer Capability (BC) associated with this MSRN is also recorded in the cache register. When the next call arrives, the GMSC first checks if a MSRN for that called mobile terminal already exists in its cache register. If a cached MSRN is available and the BC associated with the cached MSRN matches the BC requested by the current call, then the GMSC uses the cached MSRN to route the call to the VMSC. The method and system of the present invention makes it unnecessary to query the HLR and VLR when a land-to-mobile call arrives thereby increasing network capacity while reducing processing load.

Method and system for reducing call setup by roaming number caching

A method is illustrated for reducing the call setup time of high priority calls such as voice or high speed user generated data without unduly wasting RF frequency resources on non priority calls such as short message calls. This is accomplished by ascertaining the call priority at the base station controller (BSC) level in a GSM system soon after call initiation and immediately changing the channel assignment for use by the remaining signalling type messages to a different operational speed where appropriate. The concept is further extended by supplying the call priority data to a called party's BSC such that all signalling messages after initial contact can be at the operational speed appropriate to the priority of the call.

Method and apparatus for enhanced call setup

A method for ordering subscriber records in a location database stored in at least one of a Visitor Location Register (VLR) or a Home Location Register (HLR) of a wireless communications network by ordering the subscriber records in subsets according to the access rates of the records. Records within the respective subsets are then ordered in a middle-rootage order based on the subscriber ID of each subscriber record. The subscriber records are then inserted into a binary tree in subset order beginning with the subset containing subscriber records having the highest access rate. This method enables subscriber records to be more economically stored and used than is possible using conventional binary trees and, thereby, increases network capacity.

Method for ordering subscriber records of wireless communication networks

A wireless communication system constructed according to the present invention assigns mobile units to equalize loading among a plurality of mobile switching centers. The wireless communication system includes the plurality of mobile switching centers and a base station system which includes a plurality of base station controllers, each of which couples to a plurality of base stations. A plurality of mobile units served by the system are assigned to the mobile switching centers so that loading is equalized. In one particular construction of the wireless communication system, a dispatching switch couples the base station system to the plurality of mobile switching centers and performs the assignments of the mobile units. In an example of operation, upon attachment of a mobile unit, the dispatching switch determines loading of each of the mobile switching centers. Then, based upon the loading, the dispatching switch assigns the mobile unit to one of the mobile switching centers, the 'serving' mobile switching center. During subsequent calls, the dispatching switch establishes a transparent path between a base station controller servicing the call and the serving mobile switching center. Thus, once the serving mobile switching center is determined, operation is transparent to the serving base station controller and the serving mobile switching center. In another particular construction, each of the base station controllers couple to each of the mobile switching centers via a network. In such case, each of the base station controllers and each of the mobile switching centers includes additional equipment which performs at least a portion of the operations of the dispatching switch. The network may be dissimilar to a conventional data structure supported by the wireless communication system.

Scalable wireless network architecture based on subscriber distribution

A method and apparatus for scaling a wireless telecommunications network having an architecture based upon subscriber distribution includes providing a base station subsystem (BSS) and a pool of mobile switching centers (MSCs) interconnected with one another. The mobile switching centers include visitor location registers (VLRs). Lastly, a dispatcher mobile switching center (DMSC) is provided, the dispatcher mobile switching center being coupled between the base station subsystem (BSS) and the pool of mobile switching centers (MSCs) for establishing communication between the base station subsystem (BSS) and the pool of mobile switching centers (MSCs). The dispatcher mobile switching center (DMSC) further provides for distributing mobile station subscribers and call related work among the pool of mobile switching centers (MSCs).

Method and apparatus for wireless network architecture based on

A method and apparatus in a communications system for tracking mobile stations. The length and identify of the path of the mobile station is tracked at the mobile station. The path is monitored for a presence of a loop. In response in identifying the presence of a loop, the loop is removed from the path, wherein the length of the path is reduced. Additionally, the length of the path is compared to a threshold and a location update is performed in response to the length of the path being greater than the threshold. The threshold may also be updated at a MSC and then sent to the mobile station.

Method and apparatus for tracking mobile stations in a wireless

A method and system for handing over on-going communications to a target cell including a plurality of low power channels, for handling ongoing calls, and a plurality of higher power channels for handoff. The ongoing call is switched from a low to a higher power channel upon receiving a handoff request. The on-going call is using the higher power channel until a determination is made that the handoff is necessary or unnecessary. The quality of reception of the serving cell and target cell is compared to determine the necessity.

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Plano, TX, United States of America

Jim Xu