Multipoint to point radiocommunications network
US5717718A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 16, 1994 |
| Grant date | Feb 10, 1998 |
| Priority date | — |
| Expiry date | Jun 16, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2001/0093
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A data collection system in which a number of remote terminals (RT) transmit data packets for reception by one or more fixed data collectors (FDC) or a portable data collector (PDC). Each remote terminal (RT) transmits data in two frequency sub-bands to which the fixed and portable data collectors are respectively tuned. Channel capacity is improved in at least the fixed data collector (FDC) sub-band by the use in the remote terminal of minimum shift keying (MSK) encoding and pseudo-random variation of a frequency error applied to the packet transmission frequency for successive packets. In the fixed data collectors dual fast-Fourier transform signal processing enables the interpretation of simultaneous packets with different error frequencies. The use of a single design of remote terminal (RT) in conjunction with portable data collectors (PDC) simplifies system set-up, with the portable collectors providing coverage for those areas where a fixed data collector (FDC) network has yet to be established. The system has particular application to the monitoring of devices such as gas and electricity meters and security systems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.