US 6,611,529 B1 · Priority access for real-time traffic in contention-based networks

Abstract

In a contention-based network, a station, whose transmission is colliding with the transmission of another station and which heretofore would have transmitted a data packet immediately following its colliding transmission—as, for example, in a blackburst contention—suspends transmission immediately upon termination of the collision and, if necessary, at a particular point(s) in time during the collision. The station recommences transmission after a predetermined non-zero duration of time, or “time notch”, during which the medium is idle. In particular, a station that has won a blackburst contention separates its blackburst signal from its subsequent data transmission by a certain amount of time during which the medium is idle. Moreover, a station participating in a blackburst contention may cause the occurrence of a time notch at particular points in time during the contention in order that its access priority vis-a-vis other stations be determined.

Claims34

Dependent claims

A real-time communication station (RT Station) for use with a contention-based network having a plurality of said RT Stations and a communications medium, comprising:

said RT Station adapted to contend for access to said medium upon detection of a collision on said medium by transmitting a blackburst signal for a duration that is a function of at least a desired level of priority access to said medium as compared to others of said plurality of said RT Stations;
and
said RT Station further adapted to cease the transmission of said blackburst signal upon detecting said blackburst signal is the only signal being transmitted over said medium, and commence transmitting desired real-time signals upon elapse of a predetermined first non-zero duration of time after the end of the transmission of said blackburst signal.

A contention-based communications network, comprising:

a communications medium having a conventional hub, said hub enforcing at least one rule;
real-time communication stations (RT Stations), wherein ones of said RT Stations are couplable to said hub;
at least one of said RT Stations contends for access to said medium upon detection of a collision on said medium by transmitting a blackburst signal for a duration that is a function of at least a desired level of priority access to said medium as compared to others of said RT Stations;
said at least one of said RT Stations ceases transmission of said blackburst signal for a predetermined first non-zero duration of time before said at least one of said RT Stations violates said at least one rule during said transmission of said blackburst signal and then recommences said transmission of said blackburst signal;
and
said at least one of said RT Stations ceases the transmission of said blackburst signal upon detecting said blackburst signal is the only signal being transmitted over said medium, and commences transmitting desired real-time signals upon elapse of a predetermined second non-zero duration of time after the end of the transmission of said blackburst signal.

3 more elements

Dependencies are inferred from the claim text.

Priority access for real-time traffic in contention-based networks

Life of this patent

Priority access for real-time traffic in contention-based networks

Life of this patent

Abstract

Claims34