Performance improvement in wireless networks using cross-layer ARQ

Abstract

This paper presents a novel cross-layer approach (LLE-TCP) designed for performance enhancement of TCP over a large variety of wireless networks. LLE-TCP avoids TCP ACK packet transmission over the wireless channel. As a result, the saved time can be utilized by the nodes for data packet delivery. The proposed scheme enhances the protocol stacks of the wireless sender (or a base station) and the receiver with cross-layer ARQ agents which support ACK suppression. ARQ agent suppresses the outgoing ACKs at the receiver side and generates them locally at the sender or base station.The performance evaluation of the proposed approach is performed via simulations as well as IEEE 802.11 testbed experiments for single-hop and infrastructure network scenarios. LLE-TCP demonstrates the performance improvement in the range of 20-100% depending on the transmitted TCP/IP datagram size.Among the factors contributing to performance enhancement are: medium busy time reduction, reduced sensibility to link errors, reduced round trip time (RTT), and improved congestion control.A good level of throughput fairness as well as a fair coexistence with state-of-the-art TCP modifications ensures proper functionality of the proposed approach, while performance advantages extended even on non-LLE-TCP users favor an incremental deployment of the technique in existing networks.

Reliable Transmission Mechanism for safety-critical information in vehicular wireless networks

“…The sender relies on an FEC encoder module to encode the byte-level FEC redundancy. The receiver does not check the CRC error on the MAC layer and bypasses the packet to the upper layer, relying on the Datagram Congestion Control Protocol (DCCP) [11] [12]. The FEC decoder module recovers the error bytes.…”

QoS aware transmission control scheme for multihop WiMAX network

“…In [25], the retransmission priorities and the maximum number of retransmission are determined considering the TCP timing information gathered from the transport layer. Lastly, cross layer ARQ that eliminates sending TCP ACKs from the receiver was proposed in [26][27][28]. Instead, after all the link layer protocol data units (PDUs) belonging to the same TCP segment are positively acknowledged by the receiver, the TCP ACK is generated by ARQ proxy at the BS and delivered to the sender.…”

Loss Discrimination Algorithm for Wired/Wireless Networks

“…Meanwhile, in (Kliazovich et al, 2007) proposes a cross layer approach (LLE-TCP) to improve a congestion control using TCP over large variety of wireless networks. This is achieved by avoiding TCP ACK packet transmission over the wireless channel.…”

“…End-to-end TCP connection is first considered by (Kliazovich et al, 2007) over wireless links and satellite links. Instead of setting congestion window size and slow start threshold based on packet drop information as in conventional TCP, TCP Westwood (TCPW) estimates available bandwidth from the TCP sender and sets congestion window size and slow start threshold accordingly.…”