Method and system for increasing capacity and improving performance of a cellular network

• US 6,112,089 A
• Filed: 04/09/1999
• Issued: 08/29/2000
• Est. Priority Date: 07/09/1997
• Status: Expired due to Term

• Current Assignee: Apple Inc.
• Original Assignee: Northern Telecom Limited (Nortel Networks Corporation)
• Inventors: Satarasinghe, Prasanna Jayaraj
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): APPIAH, CHARLES NANA
• Application Number:
  US09/288,886
• Time in Patent Office: 508 Days
• Field of Search: 455/436, 455/437, 455/438, 455/439, 455/442, 455/525, 370/331, 370/332
• US Class Current: 455/437
• CPC Class Codes: H04W 36/00835 Determination of neighbour cell lists
• CPC Class Codes: H04W 36/0085 Hand-off measurements
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection

Abstract

A method and system for increasing capacity and improving performance of a cellular network. The method includes maintaining and analyzing matrices of a cell in the network. Once matrix stores performance values and statistics concerning the cell and optimizing conditions for handoff from the cell in response to the performance values. Another matrix stores status values and statistics concerning the cell and optimizing conditions for handoff in response to the status values. A third matrix stores information about cells that should be considered as potential handoff cells.

Claims

1. A method of optimizing a first list of potential handoff cells for a dominant cell of a cellular telephone network, the method comprising:

maintaining dynamically on a per call basis a second list of cells that are not in the first list but have had their pilot signals reported by a mobile unit operating in the dominant cell;

tracking a signal strength for the reported pilot signals of the cells in the second list; and

tracking a number of times that the pilot signals have been reported for the cells in the second list.

2. The method of claim 1 wherein, after a period of time, the tracked signal strength and tracked number of times for each pilot signal of the second list is analyzed to determine whether the corresponding cell should be included in the first list.

3. A system for optimizing a first list of potential handoff cells for a dominant cell of a cellular telephone network, the system comprising:

a second list of cells maintained dynamically on a per call basis that are not in the first list but have had their pilot signals reported by a mobile unit operating in the dominant cell;

means for tracking a signal strength for the reported pilot signals of the cells in the second list;

means for tracking a number of times that the pilot signals have been reported for the cells in the second list; and

means for analyzing the tracked signal strength and tracked number of times for each cell of the second list to determine whether that cell should be included in the first list.