Capacity evaluation of multi-channel multi-hop ad hoc networks

Proceedings of the 4th …, 1998

An ad hoc network is a collection of wireless mobile nodes dynamically forming a temporary network without the use of any existing network infrastructure or centralized administration. Due to the limited transmission range of wireless network interfaces, multiple network "hops" may be needed for one node to exchange data with another across the network. In recent years, a variety of new routing protocols targeted specifically at this environment have been developed, but little performance information on each protocol and no realistic performance comparison between them is available. This paper presents the results of a detailed packet-level simulation comparing four multi-hop wireless ad hoc network routing protocols that cover a range of design choices: DSDV, TORA, DSR, and AODV. We have extended the ns-2 network simulator to accurately model the MAC and physical-layer behavior of the IEEE 802.11 wireless LAN standard, including a realistic wireless transmission channel model, and present the results of simulations of networks of 50 mobile nodes.

2010

Wireless ad hoc network is one of the most popular network types these days. The reason for this is the advantages that wireless ad hoc networks provide for users or group of users. The most important characteristic of wireless ad hoc networks that make them more popular when compared with any other network type is that they do not need any infrastructure to be setup in advance. This characteristic of wireless ad hoc networks make the research on this topic more valuable due to increasing number of people using wireless ad hoc networks. The fact that no fixed router is used in the network ensures that network nodes are adaptable to the topology changes in a mobile wireless ad hoc network. This advantage makes wireless ad hoc networks useful in battlefield areas where there is need for networks that have a dynamic working strategy, which does not increase the complexity of setting a network. Other possible application areas of wireless ad hoc networks are disaster areas, rescue emergency operations and in vehicles that satisfies the required mobility and fast deployment network need. This thesis provides extensive real-world experimental investigation of wireless ad hoc networks with mobile and stationary nodes in different outdoor environments. The performance of wireless ad hoc networks is measured under various scenarios. For the experimental investigations, more than one network configuration and different parameters were used in real-world outdoor environment. Conducting such experiments and gathering information regarding the results of these experiments will yield very valuable information since investigation of such networks requires iv two aspects to take into account. One of them is the simulation and modeling of these networks and the other is the conducting of real-world experiments by using testbed programs. The most popular performance metrics for wireless ad hoc networks, delivery ratio, average round trip time or average end to end delay, and average number of hops were investigated in this study. It is seen that delivery ratio decreases with the distance between the nodes. The average round trip time is not affected by the distance; hence it increases with respect to application data size and the number of intermediate nodes in the network. The average number of hops changes if the distance between the source and the destination decreases since there will be no need for intermediate nodes for forwarding the packets.

Electrical Engineering Handbook, 2002

With the growing importance of wireless ad hoc networks (particularly, in applications such as wireless local area networks, and ad hoc sensor networks) it is important to develop an understanding of their performance. Performance analysis of wireless ad hoc networks is a challenging task owing to the fact that such analysis must take into account the interactions between the wireless physical layer, radio propagation, multiple access, random topology, routing, and the characteristics of the application that generates the traffic carried by the network. In this paper we discuss the major issues in the performance of wireless ad hoc networks in the light of recent research in this area. Among the topics surveyed are capacity scaling results, stochastic capacity, Bluetooth performance, and the performance of TCP.

2009

This paper presents the study of the performance study of five protocols that represent various routing categories in MANET. The set of applications for MANET's is diverse, ranging from small, static networks that are constrained by power sources, to large-scale, mobile, highly dynamic networks. The design of network routing for these networks is a complex issue. Irrespective of application, MANET's need efficient distributed algorithms to determine network organization, link scheduling, and routing. Overall, it is analyzed from the reported research papers that protocols performed much better with the group mobility model than with the random waypoint model.

Journal of Electronics (China), 2003

In this paper, we evaluate the capacity of multi-channel, multi-hop ad hoc network. In particular, we show the performance of multi-hop ad hoc network with single channel IEEE 802.11 MAC utilizing different topologies. We also introduce scaling laws of throughputs for large-scale ad hoc networks and propose the theoretical guaranteed throughput bounds for multi-channel grid topology systems. We expect that the results presented in this work will help researchers to choose the proper parameters settings in evaluation of protocols for multi-hop ad hoc networks.

2009 International Conference on Telecommunications, 2009

In this paper we examine the behavior of Ad Hoc networks through simulations, using different routing protocols and various topologies. We examine the difference in performance, using CBR application, with packets of different size through a variety of topologies, showing the impact node placement has on networks performance. We show that the choice of routing protocol plays an important role on network's performance. We also quantify node mobility effects, by looking into both static and fully mobile configurations. Our paper presents a systematic analysis of a variety of different ad hoc network topologies in terms of node placement, node mobility and routing protocols through several simulated scenarios.

IEEE/ACM Transactions on Networking, 2007

In multi-hop ad hoc networks, stations may pump more traffic into the networks than can be supported, resulting in high packet-loss rate, re-routing instability and unfairness problems. This paper shows that controlling the offered load at the sources can eliminate these problems. To verify the simulation results, we set up a real 6-node multi -hop network. The experimental measurements confirm the existence of the optimal offered load. In addition, we provide an analysis to estimate the optimal offered load that maximizes the throughput of a multi-hop traffic flow. We believe this is a first paper in the literature to provide a quantitative analysis (as opposed to simulation) for the impact of hidden nodes and signal capture on sustainable throughput. The analysis is based on the observation that a large-scale 802.11 network with hidden nodes is a network in which the carrier-sensing capability breaks down partially. Its performance is therefore somewhere between a carrier-sensing network and an Aloha network. Indeed, our analytical closed-form solution has the appearance of the throughput equation of the Aloha network. Our approach allows one to identify whether the performance of an 802.11 network is hidden-node limited or spatial-reuse limited.

The paper presents the results of a detailed packet-level simulation comparing four multi-hop wireless ad hoc network routing protocols under the load of different probability distributions, that cover a range of design choices having different protocol viz. Dynamic Source Routing Protocol (DSR), Ad-hoc On Demand Vector (AODV), Optimized Link State Routing (OLSR) and Global State Routing (GSR). We have extended the OPNET network simulator to accurately model the MAC and physical-layer behavior of the IEEE 802.11 wireless LAN standard, including a realistic wireless transmission channel model. Simulation of 100 mobile nodes has been carried out and the performance optimization is determined.

2014

In this work, we investigate the performance of Mobile Ad Hoc networks (MANETs) in terms of the throughput achieved in transferring packets from source to destination. First, we study the relationship between mobility and routing and define metrics that enable us to derive an analytical expression for the throughput. Secondly, we validate this expression, via simulations, as a function of several mobility patterns, as well as routing protocols, for various nodes speeds. Eventually, we propose the use of additional fixed relays so as to enhance the throughput performance in case of ill-behaved mobility schemes