Evaluating Mobility Predictors in Wireless Networks for Improving Handoff and Opportunistic Routing

We evaluate mobility predictors in wireless networks. Handoff prediction in wireless networks has long been considered as a mechanism to improve the quality of service provided to mobile wireless users. Most prior studies, however, were based on theoretical analysis, simulation with synthetic mobility models, or small wireless network traces. We study the effect of mobility prediction for a large realistic wireless situation. We tackle the problem by using traces collected from a large production wireless network to evaluate several major families of handoff-location prediction techniques, a set of handoff-time predictors, and a predictor that jointly predicts handoff location and time. We also propose a fallback mechanism, which uses a lower-order predictor whenever a higher-order predictor fails to predict. We found that low-order Markov predictors, with our proposed fallback mechanisms, performed as well or better than the more complex and more space-consuming compression-based handoff-location predictors. Although our handoff-time predictor had modest prediction accuracy, in the context of mobile voice applications we found that bandwidth reservation strategies can benefit from the combined location and time handoff predictor, significantly reducing the call-drop rate without significantly increasing the call-block rate. We also developed a prediction-based routing protocol for mobile opportunistic networks. We evaluated and compared our protocol\u27s performance to five existing routing protocols, using simulations driven by real mobility traces. We found that the basic routing protocols are not practical for large-scale opportunistic networks. Prediction-based routing protocols trade off the message delivery ratio against resource usage and performed well and comparable to each other

Impacts of Mobility Models on RPL-Based Mobile IoT Infrastructures: An Evaluative Comparison and Survey

With the widespread use of IoT applications and the increasing trend in the number of connected smart devices, the concept of routing has become very challenging. In this regard, the IPv6 Routing Protocol for Low-power and Lossy Networks (PRL) was standardized to be adopted in IoT networks. Nevertheless, while mobile IoT domains have gained significant popularity in recent years, since RPL was fundamentally designed for stationary IoT applications, it could not well adjust with the dynamic fluctuations in mobile applications. While there have been a number of studies on tuning RPL for mobile IoT applications, but still there is a high demand for more efforts to reach a standard version of this protocol for such applications. Accordingly, in this survey, we try to conduct a precise and comprehensive experimental study on the impact of various mobility models on the performance of a mobility-aware RPL to help this process. In this regard, a complete and scrutinized survey of the mobility models has been presented to be able to fairly justify and compare the outcome results. A significant set of evaluations has been conducted via precise IoT simulation tools to monitor and compare the performance of the network and its IoT devices in mobile RPL-based IoT applications under the presence of different mobility models from different perspectives including power consumption, reliability, latency, and control packet overhead. This will pave the way for researchers in both academia and industry to be able to compare the impact of various mobility models on the functionality of RPL, and consequently to design and implement application-specific and even a standard version of this protocol, which is capable of being employed in mobile IoT applications

The impact of mobility models on the performance of mobile Ad Hoc network routing protocol

A mobility model represents nodes distribution and movement over the network. Several research works have shown that a selection of mobility model can affect the outcome of routing performance simulation in Mobile Ad Hoc Networks. Thus, a routing protocol may only be effective in a particular mobility model or scenario but performs inferiorly in another. As a result, analyses of routing protocol performance are often based on inadequate information leading to inaccurate argument and conclusion. In this paper, three different mobility models have been selected, where each of them is highly distinctive in terms of nodes movement behavior. In addition, a new measurement technique called probability of route connectivity is introduced. The technique is used to quantify the success rate of route established by a routing protocol. Extensive simulation runs are done and results are compared between each mobility model

A performance study of routing protocols for mobile grid environment

Integration of mobile wireless consumer devices into the Grid initially seems unlikely due to limitation such as CPU performance,small secondary storage, heightened battery consumption sensitivity and unreliable low-bandwidth communication. The current grid architecture and algorithm also do not take into account the mobile computing environment since mobile devices have not been seriously considered as valid computing resources or interfaces in grid communities. This paper presents the results of simulation done in identifying a suitable ad hoc routing protocol that can be used for the target grid application in mobile environment. The simulation comparing three ad hoc routing protocols named DSDV, DSR and AODV

A study of the Destination Guided Mobility models.

Mobility models play a critical role in the simulation studies of Mobile Ad hoc Networks (MANETs). They greatly influence the performance of MANET routing protocols. For MANET simulations, random mobility models have been used in nearly all research studies in the past. In recent times, several studies have criticised the use of random mobility models in the performance studies of MANETs for the lack of realism in modelling mobility. Therefore, questions have been raised regarding the credibility of MANET simulation studies. Realism and simplicity are two attractive properties of mobility models achieving both together in modelling mobility has been a challenging task. Recently, a framework of mobility models called Destination Guided Mobility (DGM) models for MANETs with a basic software tool was proposed. This framework can be used to develop several simple DGM models with improved realism. This thesis is primarily interested in studying DGM models for their suitability in modelling mobility in various MANET scenarios. Our study requires a suitable simulation testbed for DGM models. Designing such a tool, referred to as DGMGen, with suitable functionality to study DGM models is the secondary objective of this thesis. More specifically, after the design and implementation of DGMGen, we study: i) the generality of the DGM models by modelling different real world scenarios ii) the connectivity analysis of three basic DGM models in comparison with the widely used Random Waypoint (RWP) mobility model iii) how to model a real life scenario using DGM models, based on the trace collected from that scenario and iv) the impact of DGM models on the Ad hoc On-demand Distance Vector (AODV) routing protocol using NS2. Our study shows that i) the DGM framework is powerful in capturing various MANET scenarios simply and more accurately, ii) DGM models confirm higher level connectivity prevailed in most real world scenarios, iii) DGM models can generate approximately the similar trace based on the insights of a real traceThe original print copy of this thesis may be available here: http://wizard.unbc.ca/record=b180785