The Cross-layer Adaptation of TCP-Friendly Rate Control to 3G Wireless Links

Abstract— Existing transmission control protocol (TCP) and
TCP-Friendly flows suffer from unpredictable losses and delay
over wireless links because such factors may cause sending rate
throttling and lower the reactivity of transmission control. This
paper presents a cross-layer approach to adapt TCP-Friendly rate
control (TFRC) to these two factors of 3-rd generation (3G)
wireless links. For effective adaptation, we classify the causes of
packet losses and delay observed in transport layer as:
Capacityrelated and Erroneous-channel-related, and recognize them by
using layer 2 automatic repeat-request (ARQ) information. The
proposed approach takes into account hybrid ARQ (HARQ),
adaptive modulation and coding (AMC), and layer 2 ARQ and is
simulated over the high-speed downlink packet access (HSDPA)
links. Simulation results show that our approach outperform the
standard TFRC and one other improved TFRC scheme. Besides, it
is shown that erroneous-channel-related delay adaptation makes it
possible to increase the throughput of TFRC effectively even in
cases where no erroneous-channel-related loss occurs.