Method and apparatus for use in a network of the ethernet type, to improve fairness by controlling collision backoff times and using stopped backoff timing in the event of channel capture
US5436903A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 22, 1994 |
| Grant date | Jul 25, 1995 |
| Priority date | — |
| Expiry date | Jun 22, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L12/413
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A technique for modifying the IEEE 802.3 standard for selecting backoff times in a Carrier Sense Multiple Access with Collision Detection (CSMA/CD) network, in the event that a collision is sensed by a node that has captured the network communication channel. If there is a small number of active nodes on the network, one node may capture the channel and the standard backoff algorithm makes it increasingly unlikely for another node to transmit. The new technique provides for less aggressive, i.e. longer, backoff times before at least the first retransmission attempt made by a node that has captured the channel, and in addition provides for the use of a stopped backoff algorithm. Three specific examples of methods to choose a backoff time and two methods of using a stopped backoff algorithm are disclosed. Even though the invention represents a departure from the standard CSMA/CD backoff algorithm, the overall average backoff times provided by the invention can be selected to be consistent with the average times provided by the standard. Moreover, nodes using the invention interoperate successfully with nodes that do not use the invention.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.