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Dahab, Yasser A.
- A Load Aware Routing Protocol for Mobile Ad Hoc Networks
Authors
1 Information Technology Department, Cairo University, Cairo, EG
2 Information Technology Department, Cairo University, Cairo, IN
Source
Wireless Communication, Vol 3, No 4 (2011), Pagination: 254-260Abstract
The Ad hoc On-Demand Distance Vector (AODV) routing protocol is an efficient Mobile Ad hoc NETworks (MANETs) routing protocol. It uses hop count as a metric for the path selection. AODV does not support Quality of Service (QoS) and neither any load-balancing mechanism. The performance of the network can be improved by using a load balancing mechanism. Such a mechanism transfers jobs from overloaded nodes to under loaded nodes. In this paper, we propose a new protocol called “Load-Aware AODV” (LA-AODV), to provide QoS and load-balancing features. LA-AODV is based on AODV, where protocol messages extensions are used to accomplish QoS and load-balancing features. LA-AODV is a cross-layer solution that works in conjunction with a QoS-based MAC layer. It uses only local information and does not require any additional communication or co-operation between nodes.
The path selection in LA-AODV is based on the current MAC load of the nodes. The proposed protocol selects the path with the minimum MAC load based on a metric called “MAC load indicator”. We show through simulations that LA-AODV outperforms AODV in terms of received packets, delay, and routing overhead.
Keywords
Ad hoc Networks, MANET, AODV, LA-AODV, Load balance, QoS, DCF, EDCA, DAA-EDCA, Cross Layer.
- Improving the Performance of IEEE 802.11e using A Dynamic Adaptation Approach
Authors
1 Information Technology Department, Cairo University, Cairo, EG
Source
Wireless Communication, Vol 2, No 9 (2010), Pagination: 276-280Abstract
Providing Quality of Service (QoS) for real time applications in mobile Ad hoc networks is a challenging task, due to the characteristics of the wireless links and networks. These Characteristics include: dynamic nature, infrastructure less architecture, and time varying unstable links and topology.
Features as: low cost, ease of deployment, increased coverage, and enhanced capacity make IEEE 802.11 distributed coordination function (DCF) more popular in wireless applications. However, DCF is unsuitable for real time applications which have strict demands on QoS. IEEE 802.11e Medium Access Control (MAC) was introduced to support QoS in Wireless Local Area Networks (WLANs).
Many researches have been proposed to enhance IEEE 802.11e such as Gentle Decrease, and SCW.
In this paper, we propose a new approach called “Dynamic Adaptive Approach for enhancement of EDCA” (DAA_EDCA). The proposed approach was inspired from the Gentle Decrease Scheme.
Keywords
Ad hoc Networks, MANET, QoS, DCF, EDCA, Gentle Decrease, SCW, DAA-EDCA.- A Navigation Approach for Configuring Distributed Hexagonal Metamorphic Autonomous Mobile Robots
Authors
1 Computer Engineering Department, Arab Academy for Science and Technology (AAST), Alexandria, EG
2 Electronics & Communication Engineering Department, Arab Academy for Science and Technology (AAST), South Valley branch, EG
Source
Artificial Intelligent Systems and Machine Learning, Vol 6, No 7 (2014), Pagination: 256-262Abstract
In this paper, the navigation problem for a metamorphic robotic system is addressed. The metamorphic robotic system is a composition of any number of two dimensional hexagonal autonomous mobile robots (modules), which aims to form the desired configurations.
The proposed algorithm consists of two parts, which act in centralized and decentralized form. The centralized part is utilized by the leader robot for the selection process of the local robots and for the communication with the local robots. The decentralized part is the navigation part used by each local robot to choose the next cell to be chosen in the robot movement path. This next cell is called sub-goal cell, which is one of the cells adjacent to the robot. Local robots fill in the sub-goals and then they are moving through the path to reach their goal destinations without collisions or deadlock.
As overall, the desired configuration is achieved while local robots reach their goal destinations and connect to each other. Extensive simulations are carried to show the effectiveness of the proposed algorithm.