BACKOFF SHEME FOR ACCESS COLLISION ON LOCAL AREA NETWORK

摘要

PROBLEM TO BE SOLVED: To avoid continuous access collisions between nodes which simultaneously access a network by postponing the transmission of a 1st message on a LAN only by a delay value. ;SOLUTION: A timer value generator-comparator logical block 34 outputs two bits in high order which are stored in a backoff counter 32, and a random number register 35 outputs backoff timer values 41 and 42. When a timer value of a timer 33 is equal to the timer values 41 and 42, the block 34 notifies it to a state machine 31 through a signal line 46. After the timer 33 is cleared, it counts up to fifteen in a prescribed pace. If a collision counter 48 value and a delay counter 47 value are increased, a counter 32 value is also increased. A random element is offered to a backoff scheme by using the register 35 value. The random element repeatedly avoid collision when more than two nodes are repeatedly undergone backoff at the same time and are tried to resend.;COPYRIGHT: (C)1996,JPO