Wireless communication system with dynamic channel allocation

• US 6,023,622 A
• Filed: 03/05/1997
• Issued: 02/08/2000
• Est. Priority Date: 03/05/1997
• Status: Expired due to Fees

• Current Assignee: WJ Communications, Inc. (Qorvo, Inc.)
• Original Assignee: Watkins Johnson Co. (Qorvo, Inc.)
• Inventors: Plaschke, John, Kline, Paul A., Vucetic, Jelena
• Primary Examiner(s): LE, THANH C
• Application Number:
  US08/811,574
• Time in Patent Office: 1,070 Days
• Field of Search: 455/422, 455/450, 455/452, 455/453, 455/62, 455/63, 455/446, 455/67.1, 455/67.3
• US Class Current: 455/452.2
• CPC Class Codes: H04W 16/10 Dynamic resource partitioning
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 28/16 Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service]

Abstract

A plurality of base stations communicate with a plurality of mobile units. Each base station includes a base station transceiver that receives inbound information from the mobile units and transmits outbound information to the mobile units. A mobile switching center (MSC) is coupled to the base stations and communicates the inbound information and outbound information with the base stations. The base stations each include signal detectors that detect signal strength of the inbound information, co-channel information and adjacent channel information. The MSC maintains a table of signal strength per communication channel and allocates communication channels to the base stations based on the signal strength information. The inventive dynamic channel allocation includes several channel allocation algorithms that can be active at the same time. Only one of the algorithms is active at a time. The choice of the algorithm is based on current interference conditions and traffic load. The invention is implemented in the MSC and base stations of a digital cellular network using wideband technology for its air interface. While the decision-making mechanism and the channel allocation algorithms are implemented in the MSC, the protocol between the MSC and base stations is extended to support the proposed concept for dynamic channel allocation. Advantages of the invention includes improved communication and reduced interference.

Claims

1. A wireless communication system for use with a plurality of base stations each having a cell and configured to communicate with a plurality of mobile units in each respective cell, said base stations coupled to a mobile switching center, said system comprising:

a memory configured to store a transform table containing information regarding a physical layout of a plurality of cells, a neighbors table containing information regarding adjacent cells, an interference table containing information regarding interference conditions among said cells, an allowed channels table containing information regarding channels that are allowed for utilization, and a used channels table containing information regarding channels that are used;

a detector configured to detect an inbound channel strength and an adjacent channel strength to generate a detector signal; and

a processor coupled to said memory and said detector and configured to receive said detector signal and assign communication channels to said base stations to avoid interference based at least in part on said detector signal and said tables.

2. The wireless communication system of claim 1, wherein:

said processor is configured to periodically update at least one if said tables in response to said detector signal.

3. The wireless communication system of claim 1, wherein:

said detector is configured to scan a plurality of received channels and to generate a detector signal for each of said received channels; and

said processor is configured to periodically update at least one if said tables in response to said detector signal.

4. A method of communicating between a plurality of base stations and a plurality of mobile units, where each base station has a cell and is configured to communicate with a plurality of mobile units in each respective cell, and where said base stations are coupled to a mobile switching center, said method comprising the steps of:

storing a transform table containing information regarding a physical layout of a plurality of cells;

storing a neighbors table containing information regarding adjacent cells;

storing an interference table containing information regarding interference conditions among said cells;

storing an allowed channels table containing information regarding channels that are allowed for utilization;

storing a used channels table containing information regarding channels that are used;

detecting an inbound channel strength and an adjacent channel strength and generating a detector signal; and

assigning communication channels to said base stations to avoid interference based at least in part on said detector signal and said tables.

5. The method of claim 4, further comprising the step of:

periodically updating at least one if said tables in response to said detector signal.

6. The wireless communication system of claim 4, wherein:

periodically scanning a plurality of received channels and generating a detector signal for each of said received channels; and

periodically updating at least one if said tables in response to said detector signal.