A Multiple-Collision Domain Model for Multi-Channel MACs

Abstract

This Project describes a multiple-collision domain model for multi-channel MACs and compares the behavior of that model and a single-collision domain model. First of all, a system model is used based on distances among nodes to establish if a link is possible or not between two nodes. Two ranges are defined to determine the possible links and/or conflicts among them: the transmission range and the interference range using the parameter (b). Next, a conflict graph is defined indicating the conflicts among links, with other words, it defines if a link can be established based on the links already established and links that are going to start at the same time. The model is an extension of the singlecollision domain model of (Mo et al.)[9] for multiple-collision domain. The project is focused on parallel rendezvous approach which allows to make agreements on different channels at the same time. The model uses the McMAC protocol as an example of that approach likes in single-collision domain and its hopping scheme is random hopping without control channel. The performance of the multiple-collision domain model is examined among scenarios and compared with single-collision domain model using different values of parameters. The throughput per link has been obtained numerically. The models are compared in some scenarios by varying the number of channels, probability that a node transmits p and the probability that a link ends q. The most important conclusions of the project are: To indicate that a multiple-collision domain can be modeled using set of links and the conflict graph can be used to remove the points of conflict if one link shares a certain number of single-collision domains. To show the differences between multiple-collision domain model and single-collision domain model: the first one based on links and the second one based on nodes, the size of state space of multiple-collision domain model is longer than the singlecollision domain model, unique links are going to be established and/or ended, continue inactive, continue active for multiple-collision domain model and however, a number of active pairs are going to be established and/or ended for single-collision domain and the last difference is for the points of conflict, take care with them is very important for multiple-collision domain and however, there are no points of conflict in single-collision domain. To show the behavior of the models in different scenarios. Obtaining that the links that are in the same collision domain have the same throughput but links that share a certain number of collision domains have a throughput lower than links above.