Proximity aware routing in ad hoc networks

Most of the existing routing protocols for ad hoc networks are designed to scale in networks of a few hundred nodes. They rely on state concerning all links of the network or links on the route between a source and a destination. This may result in poor scaling properties in larger mobile networks or when node mobility is high. Using location information to guide the routing process is one of the most often proposed means to achieve scalability in large mobile networks. However, locationbased routing is difficult when there are holes in the network topology. We propose a novel positionbased routing protocol called Proximity Aware Routing for Ad-hoc networks (PARA) to address these issues. PARA selects the next hop of a packet based on 2-hops neighborhood information. We introduce the concept of “proximity discovery”. The knowledge of a node’s 2-hops neighborhood enables the protocol to anticipate concave nodes and helps reduce the risks that the routing protocol will reach a concave node in the network. Our simulation results show that PARA’s performance is better in sparse networks with little congestion. Moreover, PARA significantly outperforms GPSR for delivery ratio, transmission delay and path length. Our results also indicate that PARA delivers more packets than AODV under the same conditions

Enabling architectures for QoS provisioning

Nowadays, new multimedia services have been deployed with stringent requirements for Quality of Service (QoS). The QoS provisioning is faced with the heterogeneity of system components. This thesis presents two research: on architectures for QoS management at the application layer, fulfilled mainly by software components; and on distributed software architectures for routing devices providing desired QoS at the underlying communication layer. At the application layer, the QoS architecture we propose, based on the Quality Driven Delivery (QDD) framework, deals with the increasing amount of QoS information of a distributed system. Based on various QoS information models we define for key actors of a distributed system, a QoS information base is generated using QoS information collecting and analysis tools. To translate QoS information among different components, we propose mechanisms to build QoS mapping rules from statistical data. Experiments demonstrate that efficient QoS decisions can be made effectively regarding the contribution of all system components with the help of the QoS information management system. At the underlying layer, we investigate distributed and scalable software architectures for QoS-enabled devices. Due to the huge volume of traffic to be switched, the traditional software model used for current generation routers, where the control card of the router performs all the processing tasks, is no longer appropriate in the near future. We propose a new scalable and distributed architecture to fully exploit the hardware platforms of the next generation routers, and to improve the quality of routers, particularly with respect to scalability and to a lesser extent to resiliency and availability. Our proposal is a distributed software framework where control tasks are shared among the control and line cards of the router. Specific architectures for routing, signaling protocols and routing table management are developed. We investigate the challenges for such distributed architectures and proposed various solutions to overcome them. Based on a general distributed software framework, an efficient scalable distributed architecture for MPLS/LDP and different scalable distributed schemes for the routing table manager (RTM) are developed. We also evaluate the performance of proposed distributed schemes and discuss where to deploy these architectures depending on the type of routers (i.e., their hardware capacity