Nortel Networks Corporation

Northern Telecom Limited

Wei Yuan

Sairam Subramanian

Hee C Lee

Payam Maveddat

Surnjani Djoko

Will A Egner

Kalyan K Basu

Hua Jiang

Sheng-Chou Lin

Seshu R Madhavapeddy

Shun Hua Zhou

Edith Yeh

In a LEO satellite system with the implementation of a virtual network, a method and a system are proposed for arranging an optimal route for data packets to travel. The method and system will diversify the traffic between satellites, and accordingly enhance the efficient use of the entire satellite system. An intermediary satellite is first selected between a source satellite and a destination satellite. Further, an optimal route is found among a plurality of shortest paths between the source satellite and the intermediary satellite, and subsequently another optimal route is found between the intermediary satellite and the destination satellite. Once an optimal route is determined, the route information can be encoded in the header segment of data packets. The data packets will travel from the source satellite, via the intermediary satellite, and eventually to the destination satellite without requiring any satellite to transfer routing tables, and without unnecessarily over burdening the traffic along the way between the source satellite and the destination satellite. By doing so, more communication connections can be made for billable wireless services. Moreover, a randomized selection of an intermediary satellite provides an optimal route, and consequently reduces, if not eliminates, the need for traffic congestion control.

Optimal packet routing method and system for low earth orbit satellite communication system

A personal mobility system determines a terminal address corresponding to a called user based upon a personal identifier of the called user. The personal mobility system operates in conjunction with a plurality of heterogeneous networks to provide the terminal address corresponding to the called user, independent of the particular network within which the called user currently operates. The personal mobility system includes a personal mobility user application and a personal mobility server application. The personal mobility user application receives a request from a calling user, the request including the personal identifier of a called user. The personal mobility server application couples to the personal mobility user application and includes a plurality of user records. Each user record is respective to a user and is indexed by a respective personal identifier. Further, each user record includes a plurality of terminal records with each of the terminal records including a respective terminal address. The personal mobility server application accesses the user record for the called user based upon the personal identifier, selects a terminal record of the plurality of terminal records based upon the personal identifier, and returns a respective terminal address to the personal mobility user application. The user record may also include a network usage profile and a user profile for the user which are both employed in selecting the terminal identifier.

Personal mobility and communication termination for users operating in a

A method for distributing paging load in a multicell wireless communication system establishes a plurality of location areas, with each location area including at least one cell. A load limit is based upon the greatest number of pages that may be transmitted in a particular cell over a given time period for cells of the multicell wireless communication system is determined. A paging load for the cellular wireless communication system is determined based upon historical loading and/or simulations and projections. A plurality of location areas are determined so that the paging load is distributed among the plurality of location areas such that a partial paging load respective to each cell of the multicell wireless communication system is less than a respective load limit. Boundaries of the location areas are then chosen to substantially minimize registration load within the multicell wireless communication system. In reducing registration loading, the location areas may be created so that some of the cells of the multicell wireless communication system reside in a plurality of location areas. A graph partitioning algorithm, such as a modified KL algorithm may be used to create the location areas and set the boundaries. In such operation, weights are determined for each node (cell) and edge in the graph, such weights based upon respective paging loads, non-paging loads and expected mobility between cells for the respective cell. Once these weights have been assigned, a modified KL graph partition is performed to find the location area boundaries which reduce registration loading. A multicell wireless communication system constructed according to the present invention includes a plurality of location areas having boundaries selected to reduce registration loading.

Method for distributing paging load in a cellular wireless communication

A wireless communication system includes a plurality of base stations, a plurality of base station controllers and a plurality of mobile switching centers. The plurality of base stations each support wireless communications within a respective cell and service load therein relating to subscribing units operating therein. Each of the base station controllers couples to a plurality of base stations and each of the mobile switching centers couples to at least one base station controller. The plurality of base station controllers and the plurality of mobile switching centers are managed to dynamically route load between the base station controllers and the mobile switching centers in an effort to equalize load on the plurality of mobile switching centers. At least one base station controller of the plurality of base station controllers may route its load to a first mobile switching center during a first period and route its load to the second mobile switching center during a second period. The first period and the second period may correspond to differing time periods and/or differing days. Such periods may be determined based upon historical loadings of the wireless communication system and simulation results. However, in other operations, the load is switched based upon actual system loading and the periods are determined according to the actual system loading. In other operations of the wireless communication system, a base station controller routes its load concurrently to both a first mobile switching center and a second mobile switching center of the plurality of mobile switching centers. In such operations, a first amount of load is routed to the first mobile switching center and a second amount of load routed to the second mobile switching center, such levels determined based upon loading of at least one of the first mobile switching center and the second mobile switching center.

Dynamic load distribution in a wireless communication system to equalize

A data processing system implements a load balancing methodology which recognizes the effects that multiple, mobile subscribers have within a wireless communications network. During execution of this load balancing methodology, a rehoming operation is executed at a telephone central office to move some subscribers in a network to a new home mobile switching center with a minimum number of rehoming steps. To perform this rehoming operation, a mobile switching center in a network which has a highest load is selected first. Mobile switching centers which have a load lower than a network average load are considered to be candidates for a rehome destination. All subscriber groups homed to the highest loaded mobile switching center are evaluated to determine whether or not a rehoming operation using this subscriber group would provide a highest benefit and give a lowest standard deviation of loads among mobile switching centers after the rehome operation is selected. This operation is iterative and searches for the best directory number to be homed in each candidate mobile switching center. A resulting balanced load of network resources will serve to increase the effectiveness and longevity of a current wireless communications network before additional equipment is required.

Growing community of inventors

Plano, TX, United States of America

Wei Yuan