Reliable broadcast is an essential functionality for disseminating messages to all nodes in a multi-hop wireless network. Ensuring broadcast reliability while minimizing communication overhead is a challenging task when error-prone links are considered. In this paper, we introduce and analyze techniques to address this challenge, and propose an overall algorithm encompassing a combination of the investigated techniques as an efficient solution for reliable broadcasting in multi-hop wireless networks. Simulations are conducted to validate the analytical results and to further evaluate the performance of the algorithm.

In wireless multi-hop networks, broadcasting is required for many purposes to disseminate a message to all hosts in the network, such as routing and data dissemination. Flooding is the simplest form of broadcasting, however it causes the 'broadcast storm' problem in which redundant broadcast and scheduling are two core subproblems to be solved. In this paper, we address the problem of redundant broadcast and design a new completely localized algorithm, i.e, the decision is made based on the local topology information only. The advantage of this algorithms is that it can adapt to the topology change quickly than other non-localized algorithms due to its locality while achieve even better performance in efficiency than the best known non-localized algorithm does.

A simulation study of an enhanced version of optimized link state routing is presented in this paper. Instead of periodic link state updating as in optimized link state routing (OLSR), a new form of event driven link state updating, namely delayed event driven link state updating is deployed. In this paper, the protocol is evaluated by detailed simulation experiments. The simulation results show the superiority of the proposed scheme with respect to the adaptability to mobility. The scheme combines the advantages of both periodic updating and event driven updating.

Frequent changes in network topologies caused by mobility in mobile ad hoc networks (MANETs) impose great challenges to designing routing schemes for such networks. Various routing schemes each aiming at particular type of MANET (e.g., flat or clustered MANETs) with different mobility degrees (e.g., low, medium, and high mobility) have been proposed in the literature. However, since a mobile node should not be limited to operate in a particular MANET assumed by a routing scheme, an important issue is how to enable a mobile node to achieve routing performance as high as possible when it roams across different types of MANETs. To handle this issue, a quantity that can predict the link status for a time period in the future with the consideration of mobility is required. In this paper, we discuss such a quantity and investigate how well this quantity can be used by the link caching scheme in the dynamic source routing protocol to provide the adaptability to variable topologies caused by mobility through computer simulation in NS-2.

With on-demand routing protocols for mobile ad hoc networks (MANETs), for example, dynamic source routing (DSR), a source node tries to find a route to the destination node only when it has a packet addressed to that destination node. And the source node can find a route either from its own route cache or by initializing a route discovery. To reduce the traffic generated by such route discoveries, caching of routing information is necessary. And in the design of caching schemes, cache timeout (i.e., the time period that a link would stay in the cache) is a critical parameter. However, only a few works have been done on how to set it. In this paper, we propose a new link caching scheme with adaptive timeouts. In this scheme, the cache timeout of a link is decided based on the estimation of the link's lifetime. Simulation results show that the proposed scheme can adapt to scenario changes and hence improve the performance of on-demand routing for MANETs.