A Lightweight Service Placement Approach for Community Network Micro-Clouds

Community networks (CNs) have gained momentum in the last few years with the increasing number of spontaneously deployed WiFi hotspots and home networks. These networks, owned and managed by volunteers, offer various services to their members and to the public. While Internet access is the most popular service, the provision of services of local interest within the network is enabled by the emerging technology of CN micro-clouds. By putting services closer to users, micro-clouds pursue not only a better service performance, but also a low entry barrier for the deployment of mainstream Internet services within the CN. Unfortunately, the provisioning of these services is not so simple. Due to the large and irregular topology, high software and hardware diversity of CNs, a "careful" placement of micro-clouds services over the network is required to optimize service performance. This paper proposes to leverage state information about the network to inform service placement decisions, and to do so through a fast heuristic algorithm, which is critical to quickly react to changing conditions. To evaluate its performance, we compare our heuristic with one based on random placement in Guifi.net, the biggest CN worldwide. Our experimental results show that our heuristic consistently outperforms random placement by 2x in bandwidth gain. We quantify the benefits of our heuristic on a real live video-streaming service, and demonstrate that video chunk losses decrease significantly, attaining a 37% decrease in the packet loss rate. Further, using a popular Web 2.0 service, we demonstrate that the client response times decrease up to an order of magnitude when using our heuristic. Since these improvements translate in the QoE (Quality of Experience) perceived by the user, our results are relevant for contributing to higher QoE, a crucial parameter for using services from volunteer-based systems and adapting CN micro-clouds as an eco-system for service deployment

A New Multicast Opportunistic Routing Protocol for Wireless Mesh Networks

Part 1: - PE-CRN 2011 WorkshopInternational audienceOpportunistic Routing (OR) has been proposed to improve the efficiency of unicast protocols in wireless networks. In contrast to traditional routing, instead of preselecting a single specific node to be the next-hop forwarder, an ordered set of nodes (referred to as candidates) is selected as the next-hop potential forwarders. In this paper, we propose a new multicast routing protocol based on OR for wireless mesh networks, named Multicast OR Protocol (MORP). We compare our proposal with the well known ODMRP Multicast protocol. Our results show that Multicast-OR outperforms ODMRP, reducing the number of transmissions and increasing the packet delivery ratio

Simulation of multi-radio multi-channel 802.11-based mesh networks in ns-3

In the context of wireless network simulation, many simulators are capable of evaluating the performance of single-channel network protocols, but they need many modifications to be able to simulate multi-radio multi-channel networks. We address the problem of simulating channel assignment protocols for multi-radio wireless mesh networks in ns-3 simulator, providing the essential steps needed to simulate a channel assignment protocol. In addition, we explain the details of simulating the Semi-dynamic Interference aware Channel Assignment (SICA) protocol as an example. We use SICA as a reference to address the challenges of validating and verifying the simulation model. To validate the channel assignment model in SICA, we use mathematical validation based on Markov chains. Furthermore, we propose a novel automated test module to verify the simulation process.This work has been partially supported by the Spanish Government under project TEC2012-32354 (Plan Nacional I+D) and TIN2013-47272-C2-2, and by the Catalan Government (SGR-2014-1173 and SGR-2014-881