Nortel Networks Corporation

Andrew Sendonaris

Nikhil Jain

Venugopal Veeravalli

Sairam Subramanian

Mohamed A Landolsi

Chang Yu

Stone H Tseng

Sheng-Chou Lin

Seshu R Madhavapeddy

Abdel-Ghani Daraiseh

Hongyi Chen

Seshagri Madhavapeddy

Seshu Madhava Peddy

A method for designing a soft handoff region in a wireless communications system. An inner region having an outer edge defined by a first radius is selected, wherein a mobile station communicates only with the base station within the inner region and has a selected outage probability at the outer edge of the inner region. Next, a soft handoff region having an outer edge defined by a second radius and an inner edge defined by the first radius is selected, wherein the mobile station within the soft handoff region has the selected outage probability. Actual coverage region having an outer edge defined by a third radius, wherein the third radius is selected to match soft handoff regions of other cells adjacent to the cell.

Method an apparatus for designing soft handoff regions in a wireless

The mobility of mobile subscribers within a wireless digital communications system is estimated based on highway maps and traffic data. Cells within the network are modelled as nodes connected by edges where neighboring cells are connected by roads. Each edge has two edge weight components representing traffic flow from one cell to the other and vice versa. The edge weight components are calculated from terrain factors based on the size or capacity of the roads connecting the two cells and the total traffic within the subject cell, which information may be obtained from commercial geographic databases and/or government agencies. The resulting edge weight represents an expected number of handoffs between the two cells. The problem of partitioning cells among available switches within the network is thus reduced to the purely mathematical problem of minimizing the total edge weights of edges intersected by the partition boundaries. Existing mathematical optimization techniques for optimizing node-edge systems may therefore be applied to reduce the total number of expected inter-switch handoffs as mobile subscribers pass from cell to cell within the network.

Estimation of mobility for network planning based on highway maps and

Accurate calculation of the probability of outage for a cell within a CDMA network is utilized to relate cell coverage to cell capacity. Based on a desired probability of outage, the coverage of the cell may be calculated for an average number of users within the cell. The calculation is independent of the admission policy employed to achieve the specified average number of users. The resulting closed form expression for the tradeoff between coverage and carried traffic allows an optimal design of a CDMA network.

Accurate calculation of the probability of outage for the CDMA reverse

Provided herein is a computer-implemented method for generating an optimized cellular-network cell-site plan for an area. A plurality of cellular-traffic demand nodes distributed across the area is provided. Each cellular-traffic demand node of the plurality of cellular-traffic demand nodes has an associated weighting characteristics set. The plurality of nodes are consolidated into a plurality of centroids. Each centroid represents a number of nodes that come within a traffic threshold. A potential cell site is positioned on each of the centroids. Each potential cell site has an associated base-transmitter-station parameter characteristics set. The demand node coverage of each potential cell site is determined with respect to a signal strength of the potential cell site. From the plurality of potential cell sites a minimized cell-site subset is selected while maintaining sufficient cellular service coverage of the plurality of demand nodes.

Method for optimizing cell-site placement

The optimal power allocation process of the present invention allocates power between two base stations, serving a given mobile radiotelephone, during soft hand-off. A minimum total transmit power is chosen initially. The minimum total transmit power level, the path losses for each base station, the maximum transmit power for each base station, and the minimum allowed received power are all used to generate a range of values for a transmit power level multiplier, .alpha.. The multiplier is used to allocate the total transmit power among the base stations. This process is performed until the probability of bit error is less than a maximum threshold.

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Houston, TX, United States of America

Andrew Sendonaris