On Energy Efficiency and Delay Minimization in Reactive Protocols in Wireless Multi-hop Networks

In Wireless Multi-hop Networks (WMhNs), routing protocols with energy efficient and delay reduction techniques are needed to fulfill users demands. In this paper, we present Linear Programming models (LP_models) to assess and enhance reactive routing protocols. To practically examine constraints of respective LP_models over reactive protocols, we select AODV, DSR and DYMO. It is deduced from analytical simulations of LP_models in MATLAB that quick route repair reduces routing latency and optimizations of retransmission attempts results efficient energy utilization. To provide quick repair, we enhance AODV and DSR. To practically examine the efficiency of enhanced protocols in different scenarios of WMhNs, we conduct simulations using NS- 2. From simulation results, enhanced DSR and AODV achieve efficient output by optimizing routing latencies and routing load in terms of retransmission attempts

Optimisation of Mobile Communication Networks - OMCO NET

The mini conference “Optimisation of Mobile Communication Networks” focuses on advanced methods for search and optimisation applied to wireless communication networks. It is sponsored by Research & Enterprise Fund Southampton Solent University. The conference strives to widen knowledge on advanced search methods capable of optimisation of wireless communications networks. The aim is to provide a forum for exchange of recent knowledge, new ideas and trends in this progressive and challenging area. The conference will popularise new successful approaches on resolving hard tasks such as minimisation of transmit power, cooperative and optimal routing

Performance Evaluation of Reactive Routing Protocols for IEEE 802.11

The progress of communication technology has made wireless devices smaller, less expensive and more powerful. This has initiated everyone to use various wireless network technologies such as 3G, 4G of cellular network, Ad-Hoc, IEEE 802.11 based Wireless Local Area Network (WLAN) and Bluetooth. The performance of the routing protocols AODV, DSR and LAR are compared using Qualnet 5.0.2.Network Simulator with the metrics like average jitter, throughput, end-to-end delay, total number of bytes received and packet delivery ratio successfully routed to their destination

Reliable load-balancing routing for resource-constrained wireless sensor networks

Wireless sensor networks (WSNs) are energy and resource constrained. Energy limitations make it advantageous to balance radio transmissions across multiple sensor nodes. Thus, load balanced routing is highly desirable and has motivated a significant volume of research. Multihop sensor network architecture can also provide greater coverage, but requires a highly reliable and adaptive routing scheme to accommodate frequent topology changes. Current reliability-oriented protocols degrade energy efficiency and increase network latency. This thesis develops and evaluates a novel solution to provide energy-efficient routing while enhancing packet delivery reliability. This solution, a reliable load-balancing routing (RLBR), makes four contributions in the area of reliability, resiliency and load balancing in support of the primary objective of network lifetime maximisation. The results are captured using real world testbeds as well as simulations. The first contribution uses sensor node emulation, at the instruction cycle level, to characterise the additional processing and computation overhead required by the routing scheme. The second contribution is based on real world testbeds which comprises two different TinyOS-enabled senor platforms under different scenarios. The third contribution extends and evaluates RLBR using large-scale simulations. It is shown that RLBR consumes less energy while reducing topology repair latency and supports various aggregation weights by redistributing packet relaying loads. It also shows a balanced energy usage and a significant lifetime gain. Finally, the forth contribution is a novel variable transmission power control scheme which is created based on the experience gained from prior practical and simulated studies. This power control scheme operates at the data link layer to dynamically reduce unnecessarily high transmission power while maintaining acceptable link reliability

Improving The Fault Tolerance of Ad Hoc Routing Protocols using Aspect-oriented Programming

[ES] Las redes ad hoc son redes inalámbricas distribuidas formadas por nodos móviles que se ubican libremente y dinámicamente, capaces de organizarse de manera propia en topologías arbitrarias y temporales, a través de la actuación de los protocolos de encaminamiento. Estas redes permiten a las personas y dispositivos conectarse sin problemas rápidamente, en áreas sin una infraestructura de comunicaciones previa y con un bajo coste. Muchos estudios demuestran que los protocolos de encaminamiento ad hoc se ven amenazados por una variedad de fallos accidentales y maliciosos, como la saturación de vecinos, que puede afectar a cualquier tipo de red ad hoc, y el ruido ambiental, que puede afectar en general a todas las redes inalámbricas. Por lo tanto, el desarrollo y la implementación de estrategias de tolerancia a fallos para mitigar el efecto de las fallos, es esencial para el uso práctico de este tipo de redes. Sin embargo, los mecanismos de tolerancia a fallos suelen estar implementados de manera específica, dentro del código fuente de los protocolos de encaminamiento que hace que i) ser reescrito y reorganizado cada vez que una nueva versión de un protocolo se libera, y ii) tener un carácter completamente remodelado y adaptado a las nuevas versiones de los protocolos. Esta tesis de máster explora la viabilidad de utilizar programación orientada a aspectos (AOP), para desarrollar e implementar los mecanismos de tolerancia a fallos adecuados para toda una familia de protocolos de encaminamiento, es decir, las versiones actuales y futuras de un protocolo determinado (OLSR en este caso). Por otra parte, se propone una nueva metodología para ampliar estos mecanismos a diferentes familias de protocolos proactivos (OLSR, BATMAN y Babel) con un nuevo concepto de AOP, el metaaspecto. La viabilidad y efectividad de la propuesta se ha evaluado experimentalmente, estableciendo así un nuevo método para mejorar la implementación de la portabilidad y facilidad de mantenimiento de los mecanismos de tolerancia a fallos en los protocolos de enrutamiento ad hoc y, por lo tanto, la fiabilidad de las redes ad hoc.[EN] Ad hoc networks are distributed networks consisting of wireless mobile nodes that can freely and dynamically self-organize into arbitrary and temporary topologies, through the operation of routing protocols. These networks allow people and devices to seamlessly interconnect rapidly in areas with no pre-existing communication infrastructure and with a low cost. Many studies show that ad hoc routing protocols are threatened by a variety of accidental and malicious faults, like neighbour saturation, which may affect any kind of ad hoc network, and ambient noise, which may impact all wireless networks in general. Therefore, developing and deploying fault tolerance strategies to mitigate the effect of such faults is essential for the practical use of this kind of networks. However, those fault tolerance mechanisms are usually embedded into the source code of routing protocols which causes that i) they must be rewritten and redeployed whenever a new version of a protocol is released, and ii) they must be completely redeveloped and adapted to new routing protocols. This master thesis explores the feasibility of using Aspect-Oriented Programming (AOP) to develop and deploy fault tolerance mechanisms suitable for a whole family of routing protocols, i.e. existing and future versions of a given protocol (OLSR in this case). Furthermore, a new methodology is proposed to extend these mechanisms to different families of proactive protocols (OLSR, B.A.T.M.A.N and Babel) using a new concept in AOP, the meta-aspect. The feasibility and effectiveness of the proposal is experimentally assessed, thus establishing a new method to improve the deployment, portability, and maintainability of fault tolerance mechanisms for ad hoc routing protocols and, therefore, the dependability of ad hoc networks.Bustos Rodríguez, AJ. (2012). Improving The Fault Tolerance of Ad Hoc Routing Protocols using Aspect-oriented Programming. http://hdl.handle.net/10251/18421Archivo delegad