Mobile Ad-Hoc Networks

Being infrastructure-less and without central administration control, wireless ad-hoc networking is playing a more and more important role in extending the coverage of traditional wireless infrastructure (cellular networks, wireless LAN, etc). This book includes state-of-the-art techniques and solutions for wireless ad-hoc networks. It focuses on the following topics in ad-hoc networks: quality-of-service and video communication, routing protocol and cross-layer design. A few interesting problems about security and delay-tolerant networks are also discussed. This book is targeted to provide network engineers and researchers with design guidelines for large scale wireless ad hoc networks

Implementation and analysis of location-based routing protocols for manets

This thesis concerns routing protocols for MANETs with a particular focus on location-based ones. After a deep overview of the literature, one regular routing protocol, DYMO, and two location-based (LB) ones, DYMOselfwd and AODV-Line, have been selected for further study. To this end, they have been implemented and simulated with the OMNET++ simulator. The scenarios are chosen to evaluate the impact of the node density, the nodes' mobility behaviour and of the ping payload on the performance of the routing protocols, in terms of scalability and ability to recover from route disruptions in a mobile scenario. In addition, the impact of an error in the location information is also analysed in the case of the two LB protocols

Enhancing Performance by Salvaging Route Reply Messages in On-Demand Routing Protocols for MANETs

Researchers prefer on-demand routing protocols in mobile ad hoc networks where resources such as energy and bandwidth are constrained. In these protocols, a source discovers a route to a destination typically by flooding the entire or a part of the network with a route request (RREQ) message. The destination responds by sending a route reply (RREP) message to the source. The RREP travels hop by hop on the discovered route in the reverse direction or on another route to the source. Sometimes the RREP can not be sent to the intended next hop by an intermediate node due to node mobility or network congestion. Existing on-demand routing protocols handle the undeliverable RREP as a normal data packet - discard the packet and initiate a route error message. This is highly undesirable because a RREP message has a lot at stake – it is obtained at the cost of a large number of RREQ transmissions, which is an expensive and timeconsuming process. In this paper, we propose the idea of salvaging route reply (SRR) to improve the performance of on-demand routing protocols. We present two schemes to salvage an undeliverable RREP. Scheme one actively sends a one-hop salvage request message to find an alternative path to the source, while scheme two passively maintains a backup path to the source. Furthermore, we present the design of two SRR schemes in AODV and prove that routes are loop-free after a salvaging. We conduct extensive simulations to evaluate the performance of SRR, and the simulation results confirm the effectiveness of the SRR approach

ROUTING IN MOBILE AD-HOC NETWORKS: SCALABILITY AND EFFICIENCY

Mobile Ad-hoc Networks (MANETs) have received considerable research interest in recent years. Because of dynamic topology and limited resources, it is challenging to design routing protocols for MANETs. In this dissertation, we focus on the scalability and efficiency problems in designing routing protocols for MANETs. We design the Way Point Routing (WPR) model for medium to large networks. WPR selects a number of nodes on a route as waypoints and divides the route into segments at the waypoints. Waypoint nodes run a high-level inter-segment routing protocol, and nodes on each segment run a low-level intra-segment routing protocol. We use DSR and AODV as the inter-segment and the intra-segment routing protocols, respectively. We term this instantiation the DSR Over AODV (DOA) routing protocol. We develop Salvaging Route Reply (SRR) to salvage undeliverable route reply (RREP) messages. We propose two SRR schemes: SRR1 and SRR2. In SRR1, a salvor actively broadcasts a one-hop salvage request to find an alternative path to the source. In SRR2, nodes passively learn an alternative path from duplicate route request (RREQ) packets. A salvor uses the alternative path to forward a RREP when the original path is broken. We propose Multiple-Target Route Discovery (MTRD) to aggregate multiple route requests into one RREQ message and to discover multiple targets simultaneously. When a source initiates a route discovery, it first tries to attach its request to existing RREQ packets that it relays. MTRD improves routing performance by reducing the number of regular route discoveries. We develop a new scheme called Bilateral Route Discovery (BRD), in which both source and destination actively participate in a route discovery process. BRD consists of two halves: a source route discovery and a destination route discovery, each searching for the other. BRD has the potential to reduce control overhead by one half. We propose an efficient and generalized approach called Accumulated Path Metric (APM) to support High-Throughput Metrics (HTMs). APM finds the shortest path without collecting topology information and without running a shortest-path algorithm. Moreover, we develop the Broadcast Ordering (BO) technique to suppress unnecessary RREQ transmissions

Reliable on-demand routing protocols for mobile ad-hoc networks

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University London.Mobile Ad-Hoc Network (MANET) facilitates the creation of dynamic reconfigurable networks, without centralized infrastructure. MANET routing protocols have to face high challenges like link instability, node mobility, frequently changing topologies and energy consumption of node, due to these challenges routing becomes one of the core issues in MANETs. This Thesis mainly focuses on the reactive routing protocol such as Ad-Hoc On-Demand Distance Vector (AODV) routing protocol. Reliable and Efficient Reactive Routing Protocol (RERRP) for MANET has been proposed to reduce the link breakages between the moving nodes. This scheme selects a reliable route using Reliability Factor (RF); the RF considers Route Expiration Time and Hop Count to select a routing path with high reliability and have less number of hops. The simulation result shows that RERRP outperforms AODV and enhance the packet delivery fraction (PDF) by around 6% and reduces the network routing load (NRL) by around 30%. Broadcasting in MANET could cause serious redundancy, contention, and collision of the packets. A scheme, Effective Broadcast Control Routing Protocol (EBCRP) has been proposed for the controlling of broadcast storm problem in a MANET. The EBCRP is mainly selects the reliable node while controlling the redundant re-broadcast of the route request packet. The proposed algorithm EBCRP is an on-demand routing protocol, therefore AODV route discovery mechanism was selected as the base of this scheme. The analysis of the performance of EBCRP has revealed that the EBCRP have controlled the routing overhead significantly, reduces it around 70% and enhance the packet delivery by 13% as compared to AODV. An Energy Sensible and Route Stability Based Routing Protocol (ESRSBR) have also been proposed that mainly focuses on increasing the network lifetime with better packet delivery. The ESRSBR supports those nodes to participate in the data transfer that have more residual energy related to their neighbour nodes. The proposed protocol also keeps track of the stability of the links between the nodes. Finally, the ESRSBR selects those routes which consist of nodes that have more residual energy and have stable links. The comparative analysis of ESRSBR with AODV and recently proposed routing protocol called Link Stability and Energy Aware (LSEA) routing protocol revealed that the proposed protocol ESRSBR has a significantly affect the network lifetime, increases it around 10% and 13% as compared to LSEA and AODV protocols respectively. The ESRSBR also decreases the routing overhead by 22% over LSEA and by 38% over AODV.Higher Education Commission of Pakistan and NED University of Engineering and Technology Karach