Network coding aware queue management in multi-rate wireless networks

In this thesis we focus on network coding for unicast flows, in particular we take into consideration the COPE architecture. We study what happens when two nodes transmit with different rates and we propose a Markov chain to model this scenario. Furthermore, we propose a queue management algorithm to increase the coding opportunity and the throughput of the network. In COPE, a node codes two or more packets together when packets are headed to different nexthops. When there are just packets for the same nexthop, a node loses a coding opportunity. The queue management algorithm increases the coding opportunity prioritizing the channel access of sender nodes based on the queue information and on PER of the links. We simulate this algorithm on top of COPE in a multi rate scenario with NS 2 and we show that our algorithm yields throughput gains of up to 57\% compared to COP

Network and Traffic Design Aspects in Network-Coding-Enabled Wireless Networks

Practical experience of using opportunistic network coding has already been gained in several real network deployments, indicating the influence of some of the fundamental characteristics of the network and the traffic load. However, these aspects have not been systematically investigated in the scope of the construction of efficient and robust large-scale network-coding-enabled wireless mesh networks. In this paper we focus on these aspects using an example of two opportunistic networkcoding procedures: the well-known COPE and the Bearing Opportunistic Network coding (BON). In addition, the design aspects for network-coding-enabled wireless mesh networks and applications are discussed. We have shown that opportunistic network coding can improve the performance of different networks and supported applications in terms of throughput, delay and jitter, although the benefits are not significant in all the cases. Thus, the use of opportunistic network coding should be considered upfront during the wireless network design phase in order to obtain the greatest benefits

Network coding aware queue management in multi-rate wireless networks

In this thesis we focus on network coding for unicast flows, in particular we take into consideration the COPE architecture. We study what happens when two nodes transmit with different rates and we propose a Markov chain to model this scenario. Furthermore, we propose a queue management algorithm to increase the coding opportunity and the throughput of the network. In COPE, a node codes two or more packets together when packets are headed to different nexthops. When there are just packets for the same nexthop, a node loses a coding opportunity. The queue management algorithm increases the coding opportunity prioritizing the channel access of sender nodes based on the queue information and on PER of the links. We simulate this algorithm on top of COPE in a multi rate scenario with NS 2 and we show that our algorithm yields throughput gains of up to 57\% compared to COP

Network Coding Aware Queue Management in Multi-Rate Wireless Networks

While network coding can potentially provide significant throughput benefits by combining packets prior to forwarding them, the achievable gains are directly related to the coding opportunities at a relay that performs encoding. If the relay does not have packets destined for distinct destinations, that can be encoded together, the network coding gains could be marginal. Towards increasing the opportunities for network coding, in this paper we propose a queue management scheme, that arbitrates the rate at which distinct transmitters send packets to a common relay which applies network coding. Our queue management approach prioritizes the channel access of nodes that do not have enough enqueued packets at the common relay, thereby essentially attempting to balance the number of packets from the distinct senders at the relay. We perform extensive simulations of our approach (built as a wrapper on top of the popular network coding approach COPE) in multi-rate scenarios. We find that our approach yields throughput gains of up to 57% compared to COPE due to enhanced opportunities towards encoding packets