Method and apparatus for optimal hand-offs in a satellite cellular communication system
USRE37757E1 · kind E1 · reissue
Assignee
Inventors
Key dates
| Filing date | Jul 6, 1998 |
| Grant date | Jun 18, 2002 |
| Priority date | — |
| Expiry date | Jul 6, 2018 |
Classification
- Technology area (CPC —)General
Abstract
A subscriber unit (26) communicates with a satellite communication system (10) that projects cells. The satellites (12) and cells move relative to the earth. During every other TDMA frame, a subscriber unit (26) measures the signal strength of all candidate hand-off beams. The signal strength of the current beam is compared to the signal strength of the candidate hand-off beams. When the signal strength of the current beam is not the strongest, a counter is incremented (108). A hand-off is requested to the beam with the greatest signal level when the counter exceeds a predetermined threshold. Accordingly, only after the current antenna beam has not been the strongest beam for a certain period of time, is a hand-off requested. A different counter threshold is used for candidate hand-off beams from other satellites (12).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.