Polling system for multiple terminal units
US4466001A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 4, 1981 |
| Grant date | Aug 14, 1984 |
| Priority date | — |
| Expiry date | Dec 4, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W28/14
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A semi-duplex communication system provides high channel efficiency by having the base station transmit a reference signal which each terminal uses as a sync signal. Each unit having data to send to the base responds with a very brief signal such as a burst of silent carrier transmission during an assigned time slot in a queue of slots. Only those units which responded thus are polled during the subsequent polling cycle. During the transmission time slots, the base can be sending acknowledgments to those terminal units having sent messages during the previous polling cycle. While polling for data or acknowledgments or sending acknowledgments, the base can also be listening for the respective responses. The address code of a terminal unit is further encoded to carry other required information in both directions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.