Use of cellular digital packet data (CDPD) communications to convey system identification list data to roaming cellular subscriber stations
US5920821A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 4, 1995 |
| Grant date | Jul 6, 1999 |
| Priority date | — |
| Expiry date | Dec 4, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02D30/70
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An analog cellular voice telephone system and subscriber stations associated therewith are controlled to conserve power and to provide alternate service carriers. Acquisition of all of the service carriers is facilitated through the use of system identification numbers (SIDs) associated with each service carrier. A roaming subscriber will tune to a cellular digital packet data (CDPD) frequency to obtain a list of service carriers operating within that geographical area. Based upon a comparison with a preferred SID list stored in the subscriber station, an available service carrier will be selected by the subscriber station, and registration with the selected service carrier will take place. Usually, analog voice communication is suspended until the selection process takes place.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.