Void Traversal for Guaranteed Delivery in Geometric Routing

Geometric routing algorithms like GFG (GPSR) are lightweight, scalable algorithms that can be used to route in resource-constrained ad hoc wireless networks. However, such algorithms run on planar graphs only. To efficiently construct a planar graph, they require a unit-disk graph. To make the topology unit-disk, the maximum link length in the network has to be selected conservatively. In practical setting this leads to the designs where the node density is rather high. Moreover, the network diameter of a planar subgraph is greater than the original graph, which leads to longer routes. To remedy this problem, we propose a void traversal algorithm that works on arbitrary geometric graphs. We describe how to use this algorithm for geometric routing with guaranteed delivery and compare its performance with GFG

Reliable data delivery in low energy ad hoc sensor networks

Reliable delivery of data is a classical design goal for reliability-oriented collection routing protocols for ad hoc wireless sensor networks (WSNs). Guaranteed packet delivery performance can be ensured by careful selection of error free links, quick recovery from packet losses, and avoidance of overloaded relay sensor nodes. Due to limited resources of individual senor nodes, there is usually a trade-off between energy spending for packets transmissions and the appropriate level of reliability. Since link failures and packet losses are unavoidable, sensor networks may tolerate a certain level of reliability without significantly affecting packets delivery performance and data aggregation accuracy in favor of efficient energy consumption. However a certain degree of reliability is needed, especially when hop count increases between source sensor nodes and the base station as a single lost packet may result in loss of a large amount of aggregated data along longer hops. An effective solution is to jointly make a trade-off between energy, reliability, cost, and agility while improving packet delivery, maintaining low packet error ratio, minimizing unnecessary packets transmissions, and adaptively reducing control traffic in favor of high success reception ratios of representative data packets. Based on this approach, the proposed routing protocol can achieve moderate energy consumption and high packet delivery ratio even with high link failure rates. The proposed routing protocol was experimentally investigated on a testbed of Crossbow's TelosB motes and proven to be more robust and energy efficient than the current implementation of TinyOS2.x MultihopLQI

AN IMPROVEMENT OF AODV PROTOCOL BASED ON THREADED ROUTING IN MOBILE AD HOC NETWORKS

The Mobile Ad hoc NETworks (MANETS) are suitable to be utilized in the context of an extreme emergency conditions such as battle field and disaster recovery because less requirement of infrastructure and dynamic nature. These, along with applications of these networks in military, government and in commercial area, MANETs are being researched by many organizations and institutes. Many protocols have been developed for data link layer and network layer. Many researchers have been conducted numerous simulations for comparing the performance of these protocols under varying conditions and constraints. The widely-used protocol in Mobile Ad hoc Network (MANET) achieves a dynamic, self-organizing and on-demand multi-hop routing by means of the AODV routing protocol. MANETs are characterized by self-organized, dynamic changes of network topology, limited bandwidth, and instability of link capacity, etc. The reliability of data transmission in the network cannot be guaranteed, in some special application conditions with harsh requirements on Packet Delivery Ratio (PDR) and link quality, higher criteria for routing protocol will have been laid out. This paper presents an AODV with threaded routing (AODV-FLTR) for security purpose. To reduce routing overhead and to increase packet delivery ratio, local route discovery process is used when link breaks during transmission. The performance comparison of AODV-FLTR with DSR and AODV is also carried out