Minimum-Energy Wireless Real-Time Multicast by Joint Network Coding and Scheduling Optimization

Guoping Tan,Yueheng Li,Jing Xu,Yandan Zhu,Lili Zhang

doi:10.1155/2015/390457

Abstract

For real-time multicast services over wireless multihop networks, to minimize the energy of transmissions with satisfying the requirements of a fixed data rate and high reliabilities, we construct a conflict graph based framework by joint optimizing network coding and scheduling. Then, we propose a primal-dual subgradient optimization algorithm by random samplingKmaximal stable sets in a given conflict graph. This method transforms the NP-hard scheduling subproblem into a normal linear programming problem to obtain an approximate solution. The proposed algorithm only needs to adopt centralized technique for solving the linear programming problem while all of the other computations can be distributed. The simulation results show that, comparing with the existing algorithm, this algorithm can not only achieve about 20% performance gain, but also have better performance in terms of convergence and robustness.

Highlights

Since Ahlswede et al proposed network coding (NC) [1], many studies have shown that NC can increase the throughput significantly and achieve better robustness
Lun et al proposed to decompose the multicast optimization problem into two subproblems [3]: one is to search for a NC subgraph with minimum cost by modelling as a linear or convex program problem, which can be solved by a distributed primal-dual subgradient optimization algorithm; the other is to design a network coding scheme for the optimal subgraph obtained from the first subproblem; a simple random network coding (RNC) solution can be employed for this subproblem
Wu et al proposed a distributed NC optimization algorithm over mobile ad hoc networks to minimize the energy for multicast services [4]

Summary

Introduction

Since Ahlswede et al proposed network coding (NC) [1], many studies have shown that NC can increase the throughput significantly and achieve better robustness. Using interference graph model, Jaramillo et al have studied an optimization problem on resource scheduling when realtime and non-real-time services coexist in wireless multihop networks [7]. They have studied the optimal rate allocation problem under heterogeneous delay constraints [8]. By addressing the problems mentioned above, to minimize the energy with satisfying the requirements of realtime multicast services in wireless multihop networks, we will construct a conflict graph based framework for designing joint NC subgraph and scheduling optimization algorithms.

Network Model

Optimization Framework

Optimization Algorithm

Simulation Results

Conclusions