Telecommunications – Radiotelephone system – Zoned or cellular telephone system
Patent
1996-01-26
1998-09-01
Chin, Tommy P.
Telecommunications
Radiotelephone system
Zoned or cellular telephone system
455450, 455456, 455 671, 455 674, 4552261, 4552262, H04Q 700
Patent
active
058024735
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
This invention relates to low-power wireless systems and more particularly to pico-cellular wireless systems which make use of co-located zones to permit mobility traffic.
DESCRIPTION OF THE PRIOR ART
A pico-cellular wireless system is composed of a number of wireless radio base stations which are distributed throughout a coverage area. To make effective use of these radio resources the radio base stations are physically co-located into zones of coverage known as cells. Such a pico-cellular wireless system is disclosed in applicant's co-pending application entitled "Low-Power Wireless System for Telephone Services" and having Ser. No. 07/961,769, now abandoned.
In order to provide effective wireless service in this wireless environment, an understanding of the topology of the cellular configuration is necessary. Once an understanding of the cells is in place, operations such as mobility handoff and portable location can be made to operate the system more efficiently.
In current wireless systems the manual deployment process determines the most effective placement of the wireless basestations. For example, radio base stations are placed according to estimate of traffic densities at specific locations. Once this process is complete, the grouping of radio base stations into cells must be manually entered into the system through the administration interface. That is, there are instances where two or more base stations may be required in the same zone to provide service in an area with a higher than expected traffic density. Also the information detailing the location of cells with respect to each other must be determined and entered into the system.
The cell concept allows radio channels in the allocated spectrum to be re-used provided that the cells are sufficiently far enough apart to prevent their signals from interfering. The cell concept also provides a mechanism for efficiently locating portable terminals since only one radio in the cell need be actively engaged in the search process.
This type of wireless system requires knowledge of the cell patterns in order to efficiently perform the functions of mobility handoff, arbitration and location. For example, when a portable terminal with an active radio link is about to leave the radio coverage of a cell, the manager of that cell will request neighbouring cells to pickup the radio link. Typical cell patterns include cell membership i.e. mapping of radios to a cell, and cell relationships such is as a list of neighbouring cells for a given cell.
Initially the system is geographically laid out and hard wired manually using a portable signal strength measuring device, and moving away from a fixed base station (that is transmitting a known test signal) until the received signal strength measurement from it indicates another base station is required. After installation of this next unit, the procedure is repeated until radio coverage of the desired area (e.g.: an entire building or group of buildings) is fully achieved using this layout technique. Then the whole system is mapped manually by recording, one at a time, the signal strength measurements of the various base stations at selected distances and directions from them again using the portable signal strength measuring unit.
Presently the cell mappings can be specified using a manual administration process for which the system size is no more than 36 cells. In practice all cells are defaulted to belong to the immediate neighbour list, because the provisioning task is complex and error prone.
Since this process of manual determination of cellular topologies is both tedious and error prone, it is desirable to provide a more efficient mechanism for determining cell patterns.
Even once the cell pattern is determined, the system must still be able to perform mobility operations effectively. Wireless mobility operations are concerned with providing the best link possible at all times. This is performed by allowing the portable user to stay in communication with the cell which provi
REFERENCES:
patent: 5175867 (1992-12-01), Wejke et al.
patent: 5212831 (1993-05-01), Chuang et al.
patent: 5425076 (1995-06-01), Knippelmier
patent: 5465390 (1995-11-01), Cohen
patent: 5613205 (1997-03-01), Dufour
patent: 5625889 (1997-04-01), Chikkaswamy et al.
patent: 5640414 (1997-06-01), Blakeney, II et al.
Reinink Kasper
Rutledge Philip Antony
Smith Roland A.
Wong Jin Kue
Chin Tommy P.
Fortin Jean-Pierre
Le Vu
Northern Telecom Limited
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