A testbed for MANETs: Implementation, experiences and learned lessons

In this paper, we present the implementation, experiences and lessons learned of our tesbed for Ad-hoc networks and Mobile Ad hoc Networks (MANETs). We used OLSR protocol for real experimental evaluation. We investigate the effect of mobility and topology changing in the throughput of a MANET. We study the impact of best-effort traffic for Mesh Topology and Linear Topology. In this work, we consider eight experimental models and we assess the performance of our testbed in terms of throughput, round trip time and packet loss. We found that some of the OLSR's problems can be solved, for instance the routing loop, but this protocol still has the self-interference problem. Also, there is an intricate interdependence between MAC layer and routing layer. We carried out the experiments considering stationary nodes of an Ad-hoc network and the node mobility of MANETs. We found that throughput of TCP was improved by reducing Link Quality Window Size (LQWS). For TCP data flow, we got better results when the LQWS value was 10. Moreover, we found that the node join and leave operations increase the packet loss. The OLSR protocol has a good performance when the source node is moving. However, the performance is not good when the relay nodes are moving.Peer ReviewedPostprint (published version

Usability of legacy p2p multicast in multihop ad hoc networks: an experimental study

There has recently been an increasing interest in convergence of p2p and ad hoc network research. Actually, p2p systems and multihop ad hoc networks share similar features, such as self-organisation, decentralisation, self-healing, and so forth. It is thus interesting to understand if p2p systems designed for the wired Internet are suitable also for ad hoc networks and, if they are not, in which direction they should be improved. In this paper, we report our experience in running p2p applications in real multihop ad hoc network testbeds. Specifically, we used group-communication applications that require p2p systems made up of an overlay network and a p2p multicast protocol. In this paper, we present experimental results specifically related to the performance of a well-known p2p shared-tree multicast protocol (Scribe). Our results show that such a solution is far from being efficient on ad hoc networks. We emphasize that the structured multicast approach is one of the main causes of inefficiency, and suggest that stateless solutions could be preferable

Mobility effects of wireless multi-hop networks in indoor scenarios

A Mobile Ad hoc Network (MANET) is a collection of wireless mobile terminals that are able to dynamically form a temporary network without any aid from fixed infrastructure or centralized administration. In recent years, MANETs are continuing to attract the attention for their potential use in several fields such as military activities, rescue operations and time-critical applications. In this paper, we present the implementation and analysis of our implemented wireless multi-hop network testbed considering the Optimized Link State Routing (OLSR) protocol for wireless multi-hop networking. We investigate the effect of mobility and topology changing in MANET. We study the impact of best-effort traffic for non line of sight communication. In this work, we consider three models: stationary, mobility and non line of sight communication models. We assess the performance of our testbed in terms of throughput and packet loss. From the experimental results, we found that OLSR has not a good performance when the relay node is moving. Also, the performance deteriorates when the CBR is higher.Peer ReviewedPostprint (published version

Data driven wireless network design : a multi-level modeling approach

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Performance analysis of OLSR and BATMAN protocols considering link quality parameter

In this paper, we present the implementation and analysis of our testbed considering the link quality window size (LQWS) parameter of optimized link state routing (OLSR) and better approach to mobile ad-hoc networking (B.A.T.M.A.N.) protocols. We investigate the effect of mobility in the throughput of a mobile ad-hoc network (MANET). The mobile nodes move toward the destination at a regular speed. When the mobile nodes arrive at the corner, they stop for about three seconds. In our experiments, we consider two cases: only one node is moving (mobile node)and two nodes (intermediate nodes) are moving at the same time. We assess the performance of our testbed in terms of throughput, round trip time, jitter and packet loss. From our experiments, we found that throughput of TCP was improved by reducing LQWS.Peer ReviewedPostprint (published version

Mobility effects on the performance of mobile ad hoc networks

In this paper, we present the implementation and analysis of our implemented testbed considering the Optimized Link State Routing (OLSR) protocol for Mobile Ad hoc Networks (MANET). We investigate the effect of mobility and topology changing in the throughput of MANETs. We study the impact of best-effort traffic for Mesh Topology. Experimental time is 150 seconds. In this work, we consider 6 experimental models and we assess the performance of our testbed in terms of throughput, round trip time and packet loss. From our experiments, we found that the OLSR protocol has a good performance when the source node is moving. However, the performance is not good when the three relay nodes are moving.Peer ReviewedPostprint (published version

Experimental evaluation of a MANET testbed in indoor stairs scenarios

In recent years, Mobile Ad hoc Networks (MANETs) are continuing to attract the attention for their potential use in several fields. Mobility and the absence of any fixed infrastructure make MANETs very attractive for mobility and rescue operations and time-critical applications. In this paper, we present the implementation and analysis of our implemented MANET testbed considering the Optimized Link State Routing (OLSR) protocol. We consider two models. One when all the nodes are static and another one when one node is moving. The mobile node moves toward the destination at a regular speed and when arrives at the corner of stairs is stops for about three seconds. In this work, we assess the performance of our MANET testbed in terms of throughput and packet loss. From our experiments, we found that the OLSR protocol has a good performance when nodes are in stationary state. However, when the node moves the throughput is decreased. We observed that the number of packet loss increases after 2-hops for static model and after 1-hop for moving model. But, when the node is moving, the packet loss for 2-hops to 4-hops is almost the same.Peer ReviewedPostprint (published version

FloorNet: Deployment and Evaluation of a Multihop Wireless 802.11 Testbed

A lot of attention has been given to multihop wireless networks lately, but further research—in particular, through experimentation—is needed. This attention has motivated an increase in the number of 802.11-based deployments, both indoor and outdoor. These testbeds, which require a significant amount of resources during both deployment and maintenance, are used to run measurements in order to analyze and understand the limitation and differences between analytical or simulation-based figures and the results from real-life experimentation. This paper makes two major contributions: (i) first, we describe a novel wireless multihop testbed, which we name FloorNet, that is deployed and operated under the false floor of a lab in our Computer Science building. This false floor provides a strong physical protection that prevents disconnections or misplacements, as well as radio shielding (to some extent) thanks to the false floor panels—this later feature is assessed through experimentation; (ii) second, by running exhaustive and controlled experiments we are able to analyze the performance limits of commercial off-theshelf hardware, as well as to derive practical design criteria for the deployment and configuration of mesh networks. These results both provide valuable insights of wireless multihop performance and prove that FloorNet constitutes a valuable asset to research on wireless mesh networks.European Community's Seventh Framework ProgramPublicad

Model validation through experimental testbed: the fluid flow behavior example

This testbed practice paper presents our efforts to validate an analytical model for fluid flow behavior in wireless mesh networks with an experimental evaluation. We have developed a fluid model for multihop communication in wireless mesh networks and analyzed it with simulations. Now, we describe our efforts to reproduce the modeled and simulated network with an indoorWiFi mesh network and to measure flow parameters that allow us to verify that the underlying assumptions and the flow behavior can be matched in real networks. Our experiences emphasize the need to gap the bridge between simulations and experimental validation as well as the lack of tools to efficiently validate results. These findings are particularly true in wireless mesh networks where interference is beyond the control of the experiment and where nodes are distributed such that an easy coordination and monitoring of the nodes is not possible