METHOD FOR TRANSMISSION CONTROL PROTOCOL (TCP) RATE CONTROL WITH LINK-LAYER ACKNOWLEDGEMENTS IN A WIRELESS POINT TO MULTI-POINT (PtMP) TRANSMISSION SYSTEM

摘要

A method for modifying operation of a transmission control protocol (TCP) sliding window algorithm in a wireless point to multi-point (PtMP) transmission system. The method includes ensuring that transport of a packet over a wireless telecommunications link is occurring reliably; and modifying operation of a TCP sliding window algorithm if transport is not occurring reliably in order to control a TCP transmission rate. The ensuring step includes awaiting acknowledgement of wireless transmission of the packet at a link layer over the wireless link; and retransmitting at the link layer a lost one of the packets. The link layer can be a packet-centric QoS aware media access control (MAC) layer. The modifying step includes suppressing transmission of a TCP layer communication that would cause the TCP sliding window algorithm to modify the TCP transmission rate. The suppressing step can include preventing a source TCP from retransmitting the packet. The suppressing step can include avoiding modification of a source TCP layer and a destination TCP layer. The source and destination TCP layers can be unaware of operation modification. The suppressing can include intercepting retransmission requests between a destination TCP layer of a subscriber workstation coupled to a subscriber CPE station which is in wireless communication with a wireless base station, and a source TCP layer of a host workstation coupled to the wireless base station. The method can include detecting real congestion and permitting transmission of a TCP layer communication that would cause the TCP sliding window algorithm to modify the TCP transmission rate if real congestion is detected. Here, the detecting step can include determining from the link layer whether the wireless transmission of the packet was acknowledged.