Nortel Networks Corporation

Michael John McCarthy

Srinivas Eswara

Shalini Suresh Periyalwar

Keith S Wilson

James Eric Wilson

Daniel Thomas Carter

A method and system for minimizing transmitter power levels within a cellular telephone communications network is disclosed. The method and system of the present invention are implemented within a cellular communications network which includes a cellular base station and a cellular telephone. A signal strength measurement is performed between the cellular base station and the cellular telephone. A determination is made periodically as to whether or not the measured signal strength is higher than a first threshold. In response to each determination that the measured signal strength is higher than the first threshold, the transmitter power at the cellular base station is reduced by one step such that the transmitter power levels within the cellular communications network are minimized.

Method and system for minimizing transmitter power levels within a cellular telephone communications network

Disclosed is an apparatus for reducing the number of control signal channels required in a wireless communication system by using a umbrella control signal to initially communicate with an MS (mobile station) within the umbrella and to assign the MS to a traffic frequency corresponding to one of a plurality of antenna used to cover the area covered by said umbrella control signal. Logic is used in combination with measured relative signal strengths to determine the position of the MS relative to the reliable reception coverage area of each of the plurality of antennas before the assignment is made.

Narrow beam traffic channel assignment method and apparatus

A Dynamic Frequency Association (&ldquo;DFA&rdquo;) techniques comprising fixed channel allocation (&ldquo;FCA&rdquo;) and distributed channel borrowing techniques using a segregation scheme is described. The DFA technique can be used autonomously to dynamically determine the best channels for a cell cluster. Additionally, a method of minimizing search delays at channel assignment by employing a channel usage history is disclosed. In one aspect, as in FCA, each cell is assigned its nominal channels, if any, from the available frequency spectrum, with a fixed radio assigned to each of these frequencies, respectively. Additionally, in accordance with the teachings of the present invention, each cell is equipped with one or more radios designated as &ldquo;DFA radios&rdquo;. In operation, idle DFA radios scan channels that may be borrowed in order to build a probability matrix. This enables the cell to determine which channels to use for traffic prior to actual channel request by a mobile. This reduces the search delay experienced in classic segregation schemes.

System and method of integrating dynamic frequency association with channel borrowing techniques

A method and system, for use with wireless communications systems having a cellular architecture, for achieving near real time reservation of channels in a first cell for servicing call-in-progress handoffs from other cells such that blocked calls originating within a first cell and blocked handoff of calls-in-progress from other cells are held within acceptable levels. The method and system specify that a minimum number of unutilized channels in a first cell be reserved for servicing call-in-progress handoffs. In the event that a request for a call-in-progress handoff from one of the other cells into the first cell cannot be serviced due to a lack of unutilized channels, the specified minimum number of reserved channels is dynamically adjusted upward and the request for a call-in-progress handoff that could not be serviced is enqueued. Enqueued requests are serviced in a first in first out fashion as unutilized channels become available. In the event that a request for a call-in-progress handoff from one of the other cells into the first cell can be serviced without being enqueued, the specified minimum number of reserved channels is dynamically adjusted downward such that a number of unutilized channels sufficient to service requests for handoff of calls-in-progress is dynamically maintained in a fashion that does not unduly restrict requests for call access from mobile subscriber units within the first cell.

Method of integrating handoff queuing with adaptive handoff reserve channels

A method and system for use with wireless communication systems having a cellular architecture with at least a first and a second cell. The method and system provided ensure near uniform capacity and quality of channels within the second cell via the following steps. The noise signal power in unused data channels within the second cell is monitored. When a request for channel access is received, a determination is made whether the request for channel access is either a request for handoff from the first cell into the second cell, or not. In the event that the request is not a request for handoff, a determination is made whether idle channels exist to satisfy the request for channel access. In the event of a determination either that the request for channel access is a request for handoff, or both that the request is not a request for handoff and that idle channels exist to satisfy the request, a measured received signal power of a mobile unit subscriber unit making the request is determined. One of the unused channels in the second cell is then preferentially assigned to the mobile subscriber unit where such preference in assigning is to assign a channel, provided that a signal to noise ratio calculated upon the monitored received signal power and the monitored noise signal power of the preferentially assigned noisy channel meets or exceeds a required signal to noise ratio.

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University Park, TX, United States of America

Michael John McCarthy