Performance evaluation of adjusted probabilistic broadcasting in MANETs

Appropriate use of a probabilistic broadcasting method in MANETs can decrease the number of rebroadcasts, and as a result reduce the opportunity of contention and collision among neighbouring nodes. In this paper we evaluate the performance of adjusted probabilistic flooding by comparing it to "simple" flooding as used with the ad hoc on demand distance vector (AODV) routing protocol as well as a fixed probabilistic approach. The results reveal that the adjusted probabilistic flooding exhibits superior performance in terms of both reachability and saved rebroadcast

EZ-AG: Structure-free data aggregation in MANETs using push-assisted self-repelling random walks

This paper describes EZ-AG, a structure-free protocol for duplicate insensitive data aggregation in MANETs. The key idea in EZ-AG is to introduce a token that performs a self-repelling random walk in the network and aggregates information from nodes when they are visited for the first time. A self-repelling random walk of a token on a graph is one in which at each step, the token moves to a neighbor that has been visited least often. While self-repelling random walks visit all nodes in the network much faster than plain random walks, they tend to slow down when most of the nodes are already visited. In this paper, we show that a single step push phase at each node can significantly speed up the aggregation and eliminate this slow down. By doing so, EZ-AG achieves aggregation in only O(N) time and messages. In terms of overhead, EZ-AG outperforms existing structure-free data aggregation by a factor of at least log(N) and achieves the lower bound for aggregation message overhead. We demonstrate the scalability and robustness of EZ-AG using ns-3 simulations in networks ranging from 100 to 4000 nodes under different mobility models and node speeds. We also describe a hierarchical extension for EZ-AG that can produce multi-resolution aggregates at each node using only O(NlogN) messages, which is a poly-logarithmic factor improvement over existing techniques

An Adaptive Probabilistic Model for Broadcasting in Mobile Ad Hoc Networks

Ad hoc peer-to-peer mobile phone networks (phone MANETs) enable cheap village level telephony for cash-strapped, off-the-grid communities. Broadcasting is a fundamental operation in such manets and is used for route discovery. This paper proposed a new broadcast technique that is lightweight, efficient and incurs low latency. Using extensive simulations, we compare our proposed technique to existing lightweight protocols. The results show that our technique is successful in outperforming existing lightweight techniques on the criteria that are critical for a phone-MANET.

MANET Network Management and Performance Monitoring for NHDP and OLSRv2

Mobile Ad Hoc NETworks (MANETs) are generally thought of as infrastructureless and largely ``un-managed'' network deployments, capable of accommodating highly dynamic network topologies. Yet, while the network infrastructure may be ``un-managed'', monitoring the network performance and setting configuration parameters once deployed, remains important in order to ensure proper ``tuning'' and maintenance of a MANET. This memorandum describes a management framework for the MANET routing protocol OLSRv2, and its constituent protocol NHDP. It does so by presenting considerations for ``what to monitor and manage'' in an OLSRv2 network, and how. The approach developed is based on the Simple Network Management Protocol (SNMP), and thus this paper details the various Management Information Bases (MIBs) for router status monitoring and control -- as well as a novel approach to history-based performance monitoring. While SNMP may not be optimally designed for MANETs, it is chosen due to it being the predominant protocol for IP network management -- and thus, efforts are made in this paper to ``adapt'' the management tools within the SNMP framework for reasonable behavior also in a MANET environment

Flooding control in route discovery for reactive routing in mobile ad hoc networks

Routing is a very important function in the network layer of the OSI model for wired and wireless networks. Mobile Ad hoc Networks (MANETs) are a collection of wireless nodes forming a temporary network that is supposed to be constructed on the fly without infrastructure and prior setup. This fashion of setup demands that the nodes act as routers for other nodes. This necessitates the need of a robust dynamic routing scheme. Routing protocols are classified into three main categories: proactive, reactive, and hybrid. Reactive routing has been the focus of research in recent years due to its control traffic overhead reduction. Reactive routing operation involves three main steps: route discovery, packet delivery, and route maintenance. If a source node, initiating the message, knows the route to the destination, this route is used to transmit the message; otherwise, the source node will initiate a route discovery algorithm to build the route, which highlights the importance of this phase of the on-demand routing process. This thesis work will present a route discovery algorithm that will try to find the route between the sender and the intended receiver in relatively short periods of end-to-end delay, least amount of control traffic overhead, and a loop free path between the two communicating parties. Furthermore, performance comparison between the proposed algorithm and other standard algorithms, namely basic flooding and flooding with self-pruning, will be conducted. The proposed route discovery algorithm can be used in several approaches serving ad hoc network setup, where connectivity establishment and maintenance is important