HF radio communication systems with frequency management
US4980924A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 19, 1988 |
| Grant date | Dec 25, 1990 |
| Priority date | — |
| Expiry date | Sep 19, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L5/1438
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An HF communications system comprising a plurality of radio stations, each radio station including a transceiver and a control means therefor, the control means including a processor and a memory, the memory storing a model of the ionosphere of a designated region in digital form, wherein the order to establish reliable communications channels between the stations, the system undergoes the following procedure: a first station computes from its stored model a propagation frequency window and determines a set of communications channels within the frequency window, the transceiver of the station thereafter monitoring the noise and interference present in the set of channels in order to reject channels having noise and interference levels higher than a predetermined level, and the first station establishing communications with one or more second stations on communication channels of the set in order to actively sound the channels in order to establish which channels are suitable for message transmission. In order to cater for disturbed ionospheric conditions a maximum usable frequency may be determined experimentally in a network setting up procedure or prior to any conversation betwee…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.