3 research outputs found
Joint Rate Selection and Wireless Network Coding for Time Critical Applications
In this paper, we dynamically select the transmission rate and design
wireless network coding to improve the quality of services such as delay for
time critical applications. With low transmission rate, and hence longer
transmission range, more packets may be encoded together, which increases the
coding opportunity. However, low transmission rate may incur extra transmission
delay, which is intolerable for time critical applications. We design a novel
joint rate selection and wireless network coding (RSNC) scheme with delay
constraint, so as to minimize the total number of packets that miss their
deadlines at the destination nodes. We prove that the proposed problem is
NPhard, and propose a novel graph model and transmission metric which consider
both the heterogenous transmission rates and the packet deadline constraints
during the graph construction. Using the graph model, we mathematically
formulate the problem and design an efficient algorithm to determine the
transmission rate and coding strategy for each transmission. Finally,
simulation results demonstrate the superiority of the RSNC scheme.Comment: Accepted by 2012 IEEE Wireless Communications and Networking
Conference (WCNC
Error Correction for Cooperative Data Exchange
This paper considers the problem of error correction for a cooperative data
exchange (CDE) system, where some clients are compromised or failed and send
false messages. Assuming each client possesses a subset of the total messages,
we analyze the error correction capability when every client is allowed to
broadcast only one linearly-coded message. Our error correction capability
bound determines the maximum number of clients that can be compromised or
failed without jeopardizing the final decoding solution at each client. We show
that deterministic, feasible linear codes exist that can achieve the derived
bound. We also evaluate random linear codes, where the coding coefficients are
drawn randomly, and then develop the probability for a client to withstand a
certain number of compromised or failed peers and successfully deduce the
complete message for any network size and any initial message distributions