Ad hoc communication system
US8462691B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 28, 2008 |
| Grant date | Jun 11, 2013 |
| Priority date | — |
| Expiry date | Apr 26, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W84/18
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A number of data relay devices, e.g. mobile telephones, (10, 20, 30, 40, 50, 60, 70, 80), are conveyed by vehicles and move relative to each other. They form a vehicular ad hoc wireless network (19, 29, 39, 49), etc in which data stored by a device (20) (either own-generated or relayed from another device (10) is transmitted either directly or by means of one or more other devices (30) to a network access point (90) which interfaces with a cellular network. When two devices (20, 30) come into proximity to each other, they use an opportunistic routing algorithm to determine a forwarding direction for the data. A retransmit timer is triggered on transmission of data, and messages which are unacknowledged at the expiry of the timer period are retransmitted. The timer period dynamically follows local congestion conditions and is recalculated at each transmission by the expression, timer minimum period/recent forwarding success(t). The current recent forwarding success at time t, RFS(t), is calculated from the RFS(t−1) calculated for the immediately preceding transmission and from the current forwarding success, CFS, by the expression RFS(t)=4/5 RFS(t−1)+1/5 CFS(t) where CFS is the squa…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.