Local synchronous bandwidth allocation in a token ring network
AssigneeThe Texas A&M University System
InventorsWei Zhao, Biao Chen, Gopal Agrawal
Life of this patent
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Abstract
A method for real time message transmission in a token ring network is provided. The method initializes each node in the network, including setting a maximum message transmission time H.sub.i for node i such that ##EQU1## where C.sub.i is the transmission time of a message in a message stream, P.sub.i is the period length of the message stream, and a is a non-negative constant between zero and one. The messages are then transmitted when a token arrives at a node for the duration of H.sub.i. Using this method with the timed token protocol, the synchronous messages are guaranteed to be transmitted before their deadlines if the utilization of synchronous messages is no more than ##EQU2## of available utilization.
Claims10
A method for real time message transmission in a token ring network having a plurality of nodes, comprising the steps of:
- initializing each node in the network, including setting a maximum message transmission time H.sub.i for each node i, ##EQU25## where C.sub.i is a transmission time of a message in a message stream, P.sub.i is the period length of the message stream, TTRT is a target token rotation time, and a is a non-negative constant;
- and
- transmitting said message stream when a token arrives at a node for duration of H.sub.i.
In a token ring network connecting a plurality of nodes, said nodes communicating with one another by transmitting messages, and said nodes transmit said messages only when a token is received, a method for allocating a maximum message transmission time H.sub.i for each node i, the method comprising the steps of:
- computing for H.sub.i, such that:
- ##EQU26## where C.sub.i is a transmission time of a message in a message stream, P.sub.i is a period length of the message stream, a is a non-negative constant;
- and TTRT is a target token rotation time;
- initializing each node i with respective computed H.sub.i ;
- and
- transmitting said messages when said token is captured by node i for the duration of respective computed H.sub.i.
Apparatus for allocating a maximum message transmission time H.sub.i for node i in a token ring network connecting a plurality of nodes, said nodes communicating with one another by transmitting messages, and said nodes transmit said messages only when a token is received, the apparatus comprising:
- a processor computing for H.sub.i, such that:
- ##EQU27## where C.sub.i is a transmission time of a message in a message stream,P.sub.i is the period length of the message stream, TTRT is a target token rotation time, and a is a non-negative constant;
- means for initializing each said nodes with respective computed H.sub.i ;
- and
- means for transmitting said messages for the duration of respective computed H.sub.i when said token is received at node i.
Apparatus for allocating a maximum message transmission time H.sub.i for node i in a token ring network connecting a plurality of nodes, said nodes communicating with one another by transmitting messages, and said nodes transmit said messages only when a token is received, the apparatus comprising:
- a processor computing for H.sub.i, such that:
- ##EQU28## where C.sub.i is a transmission of a message in a message stream, TTRT is a target token rotation time, and P.sub.i is the period length of the message stream;
- means for initializing each said nodes with respective computed H.sub.i ;
- and
- means for transmitting said synchronous messages for the duration of respective computed H.sub.i when said token is received at node i.
Dependencies are inferred from the claim text.