Efficient Distribution of Large Files in UMTS Supported by Network Coded M2M Data Transfer with Multiple Generations

Abstract

Abstract. This paper is a sequel of previous work, in which we have studied the traffic management problem in UMTS. The main objective was to improve the spectral efficiency of cellular networks by employing network coding supported direct mobile-to-mobile communication on usually underloaded uplink channels for the distribution of a delay insensitive popular content in multicast manner. Simulations demonstrate the noticeable performance enhancement in terms of file download times and at the same time a substantial reduction of the number of necessary transmissions in both uplink and downlink directions. However, popular content is often too large to be processed with a straightforward realization of network coding; combining the entire file to construct a single encoded block is impractical due to high encoding and decoding costs. To circumvent this problem, a novel concept is proposed in this paper. The scheme is based on processing popular content of virtually arbitrary size by embedding multiple generations into network coding.Key words: improvement in information distribution, direct mobile-tomobile communication, network coding, multiple generations. Related Previous WorkThe aim of the analysis performed in the previous paper [PSGK07] was to improve the interaction between cellular and peer-to-peer networks by generalizing the traditional scheduling paradigm. A network coding technique [ACLY00, FBW05] was embedded as a solution to the scheduling problem in the distributed dynamic environment of wireless large-scale networks. We have investigated the performance of the Universal Mobile Telecommunication System (UMTS) in terms of improvement in information distribution and dependability of information distribution among users by using direct mobile-to-mobile (m2m) data transmission mode. We have shown how, and in which terms network coding can thereby help. We have been especially interested in the distribution of the file download times for m2m users in different states of the download progress.