Throughput-Energy Efficiency Performance of TCP with Link Layer FEC/ARQ on Wireless Links

Abstract

In this paper, we investigate the throughput-energy efficiency performance of TCP Tahoe and Reno on wireless links using a FEC/ARQ protocol at the link layer. The effect of link layer (LL) parameters like the LL packet size, number of LL retransmission attempts, and FEC code rate on the TCP performance is evaluated. It is shown that the retransmissions at the link layer must persist long enough to outlast the average bad state duration of the multipath Rayleigh fading process in order to achieve throughput performance better than TCP without ARQ at the link layer. We also evaluate the energy consumption performance of TCP Tahoe and Reno with and without LL FEC/ARQ by defining energy efficiency as the average number of successful TCP packet transmissions per unit energy consumed. It is shown that without LL ARQ, using TCP Reno instead of TCP Tahoe leads to some degradation in throughput and a much more significant degradation in energy efficiency. However, with a suitable LL ARQ in place, TCP Reno performs as good as TCP Tahoe.

Indexing terms:

• Energy efficiency
• TCP
• FEC/ARQ
• Wireless

Additional information

Notes on contributors

A Chockalingam

A Chockalingam born in Raja-palayam, Tamilnadu State, India. He received the BE (Honours) degree in Electronics and Communication Engineering from the PSG College of Technology, Coimbatore, India, in 1984, the MTech degree with specialization in satellite communications from the Indian Institute of Technology, Kharagpur, India, in 1985, and the PhD degree in Electrical Communication Engineering (ECE) from the Indian Institute of Science (IISc), Bangalore, India, in 1993.

During 1986 to 1993, he worked with the Transmission R&D division of the Indian Telephone Industries Ltd., Bangalore. From December 1993 to May 1996, he was a Postdoctoral Fellow and an Assistant Project Scientist at the Department, of Electrical and Computer Engineering, University of California, San Diego (UCSD), where he conducted research in DS-CDMA wireless communications. From May 1996 to December 1998, he served Qualcomm, Inc, San Diego, CA, as a Staff Engineer/Manager in the systems engineering group, in December 1998, he joined the faculty of the Department of ECE, IISc, Bangalore, India, where he is an Assistant Professor, working in the area of wireless communications, and directing research at the Wireless Research Lab (WRL), IISc. He was a visiting faculty to UCSD during summer 1999 and 2000. Dr Chockalingam is a recipient of the CDIL (Communication Devices India Ltd) award and Prof S K Chatterjee research grant award. His research interest lie in the area of DS-CDMA systems and wireless networks and protocols.