System and method for CDMA handoff using telemetry to determine the need for handoff and to select the destination cell site
US6061337A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 2, 1996 |
| Grant date | May 9, 2000 |
| Priority date | — |
| Expiry date | Dec 2, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W36/326
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A system and method for measuring the approximate distance and direction of a mobile unit from a plurality of cells in order to determine whether and how to handoff the mobile unit and which cell may be the best serving cell. The CDMA timing system is used to provide an estimate of the subscriber's location to be determined by a CDMA base station. A distance calculation is made by the serving cell site sending a request for signal strength message to a mobile unit. The mobile unit measures pilot signal strength and a time offset from the expected time of such pilot signals. The signal strength and time offsets are returned to the cell site. a processor in the system can then determine if a handoff is really desirable, and with which of the cell sites is the best serving all for the mobile unit the mobile unit with a high degree of confidence that the call will be maintained. Also, an adaptive database may be implemented wherein a mobile unit is tracked to the edge of the coverage area and, a database is kept of successful handoffs to another carrier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.