Sharif Digital Repository

By occurring failures in computer networks, routing protocols are triggered to update routing and forwarding tables. Because of invalid tables during update-time, transient loop may occur and packet-drop rate and end-to-end delay increase which means that the quality of service decreases. This paper proposes a parallel architecture for a router to recalculate and update routing table. Simulation results show that with dual-processor architecture, this update time could be up to 40% improved, depending on the network topology and the size of tables. This paper also studies the effect of this speed-up on networks' performability, i.e. the ability to deliver services at predefined level. A... 

A wireless sensor network with a large number of small sensor nodes can be used as an effective tool for gathering data in various situations. Energy is a critical resource in wireless sensor networks and system lifetime needs to be prolonged through the use of energy-aware strategies during system operation. Routing protocols in WSNs might differ depending on the application and network architecture. Many routing protocols have been specifically designed for WSNs where energy awareness is an essential design issue. The aim of this paper is to evaluate the efficiency of a routing protocol named directed flooding which is a fault-tolerant and energy efficient routing protocol for wireless... 

The authors investigate the content distribution among the vehicles of a cluster in a vehicular ad-hoc network, exploiting network coding. The vehicles collaborate to disseminate the coded data packets, received from a roadside info-station based on IEEE 802.11 medium access control (MAC) protocol. Two types of network coding are considered: random linear network coding (RLNC) over a large finite field and random XORed network coding (RXNC). An analytical model is proposed to address the effect of random access MAC as well as the correlation among received coded packets on the performance of content distribution. First, a p-persistent carrier sense multiple access approximation for IEEE... 

A Mobile Ad hoc Network (MANET) is a collection of wireless mobile nodes forming a self-configuring network without using any existing infrastructure. Since MANETs are not currently deployed on a large scale, research in this area is mostly simulation based. Among other simulation parameters, the mobility model plays a very important role in determining the protocol performance in MANET. Thus, it is essential to study and analyze various mobility models and their effect on MANET protocols. In this paper we introduce a new framework for simulation of mobility models in mobile Ad-Hoc networks. This simulator can generate mobility traces in various mobility models. The mobility traces can be... 

A Mobile Ad hoc Network (MANET) is a collection of wireless mobile nodes forming a self-configuring network without using any existing infrastructure. Network nodes in a mobile Ad-hoc network move in some motion patterns called mobility models. The mobility models play a very important role in determining the protocol performance in MANET. Thus, it is essential to study and analyze various mobility models and their effect on MANET protocols. If we can recognize the mobility pattern of motion of mobile nodes in our environment we can customize our network protocols to deal with that existing mobility model. In this paper we introduce a new method for classification and pattern recognition of... 

Mobile Ad Hoc Networks (MANETs) are networks with selforganizing capabilities and without a fixed infrastructure. Wireless nodes communicate among themselves using multi-hop radio relaying, without requiring the packets to pass through a central access point or a base station. In a highly mobile and infrastructure-less scenario, pre-configuration of addresses is not possible. Therefore node addresses need to be configured dynamically with minimum delay and packet loss. Existing solutions for IP address auto-configuration do not address security issues. In this paper we propose a secure address autoconfiguration for Mobile Ad hoc Networks (MANET) based on Virtual Address Space Mapping [1]....