Preferred carrier selection method
US6016427A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 18, 1998 |
| Grant date | Jan 18, 2000 |
| Priority date | — |
| Expiry date | Mar 18, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W84/042
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method and an apparatus for selecting a cellular carrier frequency for accessing cellular airtime services based upon a list of preferred system identification codes (SIDs). A cellular telephone is programmed to accept into memory a list of preferred SIDs corresponding to carriers through which service is preferred. While any SID remains in a preferred list, the standard A/B system selection function is replaced by a substitute system selection function which includes only three carrier selection modes including the Home Only mode, the SID Only mode, and a Roam Saver mode. With the Roam Saver carrier selection mode, the cellular telephone first prefers service through a home carrier and then through a carrier broadcasting a SID matching a SID on the preferred list, but never denies service to emergency or non-emergency destinations if any SID is detected. Status indicators are used to, among other purposes, differentiate between no service being available, service being available through a carrier broadcasting a home SID, a preferred SID, or a non-preferred available SID. Also, in addition to multiple number assignment modules (NAMs) being included to support subscriptions to ser…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.