Modeling the Effect of Forwarding in a Multi-hop Ad Hoc Networks with Weighted Fair Queueing
Consider a wireless ad hoc network with random access channel. We present a model that takes into account topology, routing, random access in MAC layer (governed by IEEE 802.11orslotted aloha) and forwarding probability. In this paper , we are focusing to
- PDF / 670,683 Bytes
- 14 Pages / 430 x 660 pts Page_size
- 51 Downloads / 194 Views
tract. Consider a wireless ad hoc network with random access channel. We present a model that takes into account topology, routing, random access in MAC layer (governed by IEEE 802.11orslotted aloha) and forwarding probability. In this paper , we are focusing to study the effect of cooperation on the stability and throughput of ad-hoc network. Forwarding packets of other nodes is an example of activity that requires such a collaboration. Hence, it may not be in interest of a node to always forward the requesting packet. We propose a new approach (based on cycle of transmissions) to derive throughput of multi-hop routes and stability of forwarding queues. With this cycle approach, we correct the analytical expressions derived in [2] and discover that their results are valid only in particular cases such as symmetric networks. However, in this paper, we get extended results for general network case. Moreover, we confirm that (i) the forwarding queues in a system of weighted fair queues has a special property and (ii) the end to end throughput of a connection does not depend on the load of the intermediate forwarding queues between a source and a destination. We perform extensive simulations and verify that the analytical results exactly match the results obtained from simulations.
1
Introduction
A multi-hop wireless ad hoc network is a collection of nodes that communicate with each other without any established infrastructure or centralized control. Each of these nodes is a wireless transceiver that transmits and receive at a single frequency band which is common to all the nodes. These nodes can communicate with each other, however, they are limited by their transmitting and receiving capabilities. Therefore, they cannot directly reach all of the nodes in the network as most of the nodes are outside of direct range. In such a scenario, one of the possibilities for the information transmission between two nodes that are not in position to have a direct communication is to use other nodes in the network. To be precise, the source device transmits its information to one of the devices which is within transmission range of the source device. In order to overcome this, the network operates in a multi-hop fashion. Nodes route traffic for each other. Therefore, in a connected ad hoc network, a packet can travel from any source to its destination either directly, or through some set of intermediate packet forwarding nodes. H. Zhang et al. (Eds.): MSN 2007, LNCS 4864, pp. 5–18, 2007. c Springer-Verlag Berlin Heidelberg 2007
6
R. El Khoury and R. El-Azouzi
Clearly, a judicious choice is required to decide on the set of devices to be used to assist in the communication between any two given pair of devices. This is the standard problem of routing in communication networks. The problem of optimal routing has been extensively studied in the context of wire-line networks where usually a shortest path routing algorithm is used: Each link in the network has a weight associated with it and the objective of the routing algorithm i
Data Loading...
