Arbitration mechanism for statistically multiplexed frame relay switching system
First Claim
1. For use with a frame relay switching system having a plurality of frame relay channel units coupled to respective access lines for associated user equipments, and multiplexing data from said access lines onto an aggregate data communication link having a limited bandwidth less than the cumulative data capacity of said access lines, and an arbitration link through which said frame relay channel units share arbitration information representative of their right to transmit over said limited bandwidth aggregate data communication link, a method of arbitrating the allocation of said limited bandwidth aggregate data communication link among said access lines comprising the steps of:
- (a) in response to a request from an access line to transmit data supplied thereby over said limited bandwidth aggregate data communication link, generating an arbitration code that includes information representative of whether its associated access line has data to be transmitted, and an arbitration value based upon queuing delay of data supplied by said associated access line and information customized for said associated access line;
(b) coupling said arbitration codes generated in step (a) to said arbitration link;
(c) determining which channel unit has priority to transmit data over said limited bandwidth aggregate data communication link in accordance with arbitration codes coupled to said arbitration link; and
(d) selectively granting said channel unit the right to transmit data provided by its associated access line over said limited bandwidth aggregate data communication link, in response to its arbitration code being representative that said associated access line has transmission priority over all other access lines of said plurality.
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Accused Products
Abstract
An arbitration mechanism is distributed among channel units of a statistically multiplexed frame relay switching system serving a plurality of access lines, the cumulative bandwidth of which exceeds that of an aggregate data link over which data is to be transported. For each access line, an arbitration code is generated. This code includes a transmit request or start bit, a calculated multibit arbitration value based upon a combination of parameters, including queuing delay and the configuration and traffic rate of the line, and an address code that identifies the physical location of the respective channel unit. All arbitration codes are readable by each frame relay channel unit via a wire-ORed bus. A channel unit participating in an arbitration cycle compares the value of its arbitration code with those of the other participants. That channel unit whose arbitration code is uniquely the largest of all arbitration participants takes ownership of the aggregate data link, transmits data, and then releases the link.
32 Citations
18 Claims
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1. For use with a frame relay switching system having a plurality of frame relay channel units coupled to respective access lines for associated user equipments, and multiplexing data from said access lines onto an aggregate data communication link having a limited bandwidth less than the cumulative data capacity of said access lines, and an arbitration link through which said frame relay channel units share arbitration information representative of their right to transmit over said limited bandwidth aggregate data communication link, a method of arbitrating the allocation of said limited bandwidth aggregate data communication link among said access lines comprising the steps of:
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(a) in response to a request from an access line to transmit data supplied thereby over said limited bandwidth aggregate data communication link, generating an arbitration code that includes information representative of whether its associated access line has data to be transmitted, and an arbitration value based upon queuing delay of data supplied by said associated access line and information customized for said associated access line;
(b) coupling said arbitration codes generated in step (a) to said arbitration link;
(c) determining which channel unit has priority to transmit data over said limited bandwidth aggregate data communication link in accordance with arbitration codes coupled to said arbitration link; and
(d) selectively granting said channel unit the right to transmit data provided by its associated access line over said limited bandwidth aggregate data communication link, in response to its arbitration code being representative that said associated access line has transmission priority over all other access lines of said plurality. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A frame relay switching system comprising:
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a plurality of frame relay channel units, coupled to respective access lines for associated user equipments, and being operative to multiplex data from said access lines onto an aggregate data communication link whose bandwidth is less than the cumulative data capacity of said access lines; and
an arbitration link through which said frame relay channel units share arbitration information representative of their right to transmit over said limited bandwidth aggregate data communication link; and
an arbitration mechanism through which said aggregate data communication link is allocated among said access lines, by performing the steps of;
(a) in response to a request from an access line to transmit data supplied thereby over said limited bandwidth aggregate data communication link, generating an arbitration code that includes information representative of whether its associated access line has data to be transmitted, and an arbitration value based upon queuing delay of data supplied by said associated access line and information customized for said associated access line;
(b) coupling said arbitration codes generated in step (a) to said arbitration link;
(c) determining which channel unit has priority to transmit data over said aggregate data communication link in accordance with arbitration codes coupled to said arbitration link; and
(d) selectively granting said channel unit the right to transmit data provided by its associated access line over said aggregate data communication link, in response to its arbitration code being representative that said associated access line has transmission priority over all other access lines of said plurality. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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Specification