HYBRID ARQ SYSTEM USING A SLIDING PURGE WINDOW FOR WIRELESS NETWORKS

摘要

An IP packet transmission system is disclosed and more specifically it is a system using a hybrid ARQ method that includes a sliding purge window to reduce packet losses and improve TCP throughput thus ensuring data integrity, improving reliability, and to some extent guaranteeing in-order delivery of packets at the receiver.

主权项

1. A sliding purge window method to reduce packet losses and improve transport control protocol throughput in a wireless network between a receiver having a receive window, fed by a fragmentation buffer and a re-assembly buffer to re-assemble fragments of packets received, and a transmitter having a transmission window and that monotonically assigns each packet sent by the transmitter with a packet ID number up to a maximum packet ID number, said wireless network using a Hybrid Automatic Repeat Request transmission scheme having a re-transmission logic that ensures an oldest unacknowledged packet is re-transmitted first wherein the sliding purge method ensures that the packets in the receiver window match the packets in the transmission window such that if there is a transmission error the transmission scheme recovers and the receiver and transmitter remain in synchronization comprising;
said receiver having a sliding purge window; setting a threshold packet number for said sliding purge window that is less than the maximum packet ID number; and, said receiver purging an oldest received packet from said receiver's re-assembly buffer and fragmentation buffer each time a fragment is received by said receiver that belongs to a packet having a packet ID number that is greater than the packet ID number of a packet in the fragmentation buffer and re-assembly buffer by said threshold packet number.