Flow Allocation for Maximum Throughput and Bounded Delay on Multiple Disjoint Paths for Random Access Wireless Multihop Networks

In this paper, we consider random access, wireless, multi-hop networks, with multi-packet reception capabilities, where multiple flows are forwarded to the gateways through node disjoint paths. We explore the issue of allocating flow on multiple paths, exhibiting both intra- and inter-path interference, in order to maximize average aggregate flow throughput (AAT) and also provide bounded packet delay. A distributed flow allocation scheme is proposed where allocation of flow on paths is formulated as an optimization problem. Through an illustrative topology it is shown that the corresponding problem is non-convex. Furthermore, a simple, but accurate model is employed for the average aggregate throughput achieved by all flows, that captures both intra- and inter-path interference through the SINR model. The proposed scheme is evaluated through Ns2 simulations of several random wireless scenarios. Simulation results reveal that, the model employed, accurately captures the AAT observed in the simulated scenarios, even when the assumption of saturated queues is removed. Simulation results also show that the proposed scheme achieves significantly higher AAT, for the vast majority of the wireless scenarios explored, than the following flow allocation schemes: one that assigns flows on paths on a round-robin fashion, one that optimally utilizes the best path only, and another one that assigns the maximum possible flow on each path. Finally, a variant of the proposed scheme is explored, where interference for each link is approximated by considering its dominant interfering nodes only.Comment: IEEE Transactions on Vehicular Technolog

A New MPLS-Based Forwarding Paradigm for Multi-Radio Wireless Mesh Networks

Routing in multi-radio wireless mesh networks is a very challenging problem. In this paper, we propose a forwarding paradigm based on MPLS (Multi Protocol Label Switching) which makes use of a novel mechanism, denoted as MPLS splitting policy. Such mechanism allows to configure multiple next hops at an intermediate node, so that the incoming traffic is partitioned among the next hops according to predefined coefficients named split ratios. The MPLS splitting policy has been designed to allow for load balancing and fast local restoration. With such a mechanism, it is crucial to properly determine the set of split ratios, as they determine how the traffic is routed across the network. We present an approach to compute a set of split ratios that guarantee high performance under different traffic loads. To this end, we adopt the hose traffic model, according to which we only have knowledge of the maximum amount of traffic entering or leaving the network at each edge node. A thorough simulation study is conducted to show that our approach outperforms other routing protocols in terms of throughput and robustness against traffic load variations and single node failures