Results 1  10
of
49
The Node Distribution of the Random Waypoint Mobility Model for Wireless Ad Hoc Networks
, 2003
"... The random waypoint model is a commonly used mobility model in the simulation of ad hoc networks. It is known that the spatial distribution of network nodes moving according to this model is, in general, nonuniform. However, a closedform expression of this distribution and an indepth investigation ..."
Abstract

Cited by 372 (11 self)
 Add to MetaCart
The random waypoint model is a commonly used mobility model in the simulation of ad hoc networks. It is known that the spatial distribution of network nodes moving according to this model is, in general, nonuniform. However, a closedform expression of this distribution and an indepth investigation is still missing. This fact impairs the accuracy of the current simulation methodology of ad hoc networks and makes it impossible to relate simulationbased performance results to corresponding analytical results. To overcome these problems, we present a detailed analytical study of the spatial node distribution generated by random waypoint mobility. More specifically, we consider a generalization of the model in which the pause time of the mobile nodes is chosen arbitrarily in each waypoint and a fraction of nodes may remain static for the entire simulation time. We show that the structure of the resulting distribution is the weighted sum of three independent components: the static, pause, and mobility component. This division enables us to understand how the models parameters influence the distribution. We derive an exact equation of the asymptotically stationary distribution for movement on a line segment and an accurate approximation for a square area. The good quality of this approximation is validated through simulations using various settings of the mobility parameters. In summary, this article gives a fundamental understanding of the behavior of the random waypoint model.
Adaptive demanddriven multicast routing in multihop wireless ad hoc networks
, 2001
"... The use of ondemand techniques in routing protocols for multihop wireless ad hoc networks has been shown to have significant advantages in terms of reducing the routing protocol’s overhead and improving its ability to react quickly to topology changes in the network. A number of ondemand multicast ..."
Abstract

Cited by 160 (3 self)
 Add to MetaCart
(Show Context)
The use of ondemand techniques in routing protocols for multihop wireless ad hoc networks has been shown to have significant advantages in terms of reducing the routing protocol’s overhead and improving its ability to react quickly to topology changes in the network. A number of ondemand multicast routing protocols have been proposed, but each also relies on significant periodic (nonondemand) behavior within portions of the protocol. This paper presents the design and initial evaluation of the Adaptive DemandDriven Multicast Routing protocol (ADMR), a new ondemand ad hoc network multicast routing protocol that attempts to reduce as much as possible any nonondemand components within the protocol. Multicast routing state is dynamically established and maintained only for active groups and only in nodes located between multicast senders and receivers. Each multicast data packet is forwarded along the shortestdelay path with multicast forwarding state, from the sender to the receivers, and receivers dynamically adapt to the sending pattern of senders in order to efficiently balance overhead and maintenance of the multicast routing state as nodes in the network move or as wireless transmission conditions in the network change. We describe the operation of the ADMR protocol and present an initial evaluation of its performance based on detailed simulation in ad hoc networks of 50 mobile nodes. We show that ADMR achieves packet delivery ratios within 1 % of a floodingbased protocol, while incurring half to a quarter of the overhead. 1.
MinimumEnergy Asynchronous Dissemination to Mobile Sinks in Wireless Sensor Networks
, 2003
"... Data dissemination from sources to sinks is one of the main functions in sensor networks. In this paper, we propose SEAD, a Scalable Energye#cient Asynchronous Dissemination protocol, to minimize energy consumption in both building the dissemination tree and disseminating data to mobile sinks. SEAD ..."
Abstract

Cited by 98 (0 self)
 Add to MetaCart
Data dissemination from sources to sinks is one of the main functions in sensor networks. In this paper, we propose SEAD, a Scalable Energye#cient Asynchronous Dissemination protocol, to minimize energy consumption in both building the dissemination tree and disseminating data to mobile sinks. SEAD considers the distance and the packet tra#c rate among nodes to create nearoptimal dissemination trees. The sinks can move without reporting their location to the tree while receiving data updates successfully. Our evaluation results illustrate that SEAD consumes less energy on building and maintaining a dissemination tree to multiple mobile sinks compared to other approaches such as directed di#usion, TTDD, and mobile ad hoc multicast.
Group and swarm mobility models for ad hoc network scenarios using virtual tracks
 In Proceedings of MILCOM
, 2004
"... The mobility model is one of the most important factors in the performance evaluation of a mobile ad hoc network (MANET). Traditionally, the random waypoint mobility model has been used to model the node mobility, where the movement of one node is modeled as independent from all others. However, in ..."
Abstract

Cited by 55 (10 self)
 Add to MetaCart
The mobility model is one of the most important factors in the performance evaluation of a mobile ad hoc network (MANET). Traditionally, the random waypoint mobility model has been used to model the node mobility, where the movement of one node is modeled as independent from all others. However, in reality, especially in large scale military scenarios, mobility coherence among nodes is quite common. One typical mobility behavior is group mobility. Thus, to investigate military MANET scenarios, an underlying realistic mobility model is highly desired. In this paper, we propose a “virtual track ” based group mobility model (VT model) which closely approximates the mobility patterns in military MANET scenarios. It models various types of node mobility such as group moving nodes, individually moving nodes as well as static nodes. Moreover, the VT model not only models the group mobility, it also models the dynamics of group mobility such as group merge and split. Simulation experiments show that the choice of mobility model has significant impact on network performance. I.
The critical transmitting range for connectivity in mobile ad hoc networks
 IEEE Transactions on Mobile Computing
, 2005
"... this paper, we study the critical transmitting range (CTR) for connectivity in mobile ad hoc networks. We prove that ln n rM c n for some constant c 1, where rM is the CTR in the presence of Mlike node mobility and n is the number of network nodes. Our result holds for an arbitrary mobility model ..."
Abstract

Cited by 50 (3 self)
 Add to MetaCart
(Show Context)
this paper, we study the critical transmitting range (CTR) for connectivity in mobile ad hoc networks. We prove that ln n rM c n for some constant c 1, where rM is the CTR in the presence of Mlike node mobility and n is the number of network nodes. Our result holds for an arbitrary mobility model M such that: 1) M is obstacle free and 2) nodes are allowed to move only within a certain bounded area. We also investigate in detail the case of random waypoint mobility, which is the most common mobility model used in the simulation of ad hoc networks. Denoting with rw p the CTR with random waypoint mobility when the pause time is set to p and node velocity is set to v, we prove that rw qffiffiffiffiffi pþ0:521405 v ln n p p n if p>0 and that rw qffiffiffiffiffi ln n 0 n. The results of our simulations also suggest that if n is large enough (n 50), rw r 0 is well approximated by 4 ln n, where r is the critical range in case of uniformly distributed nodes. The results presented in this paper provide a better understanding of the behavior of a fundamental network parameter in the presence of mobility and can be used to improve the accuracy of mobile ad hoc network simulations. Index Terms—Critical transmitting range, connectivity, random waypoint model, mobility modeling, ad hoc networks. æ 1
Realworld environment models for mobile network evaluation
 IEEE Journal on Selected Areas in Communications
"... Simulation environments are an important tool for the evaluation of new concepts in networking. The study of mobile ad hoc networks depends on understanding protocols from simulations, before these protocols are implemented in a realworld setting. To produce a realworld environment within which an ..."
Abstract

Cited by 35 (1 self)
 Add to MetaCart
(Show Context)
Simulation environments are an important tool for the evaluation of new concepts in networking. The study of mobile ad hoc networks depends on understanding protocols from simulations, before these protocols are implemented in a realworld setting. To produce a realworld environment within which an ad hoc network can be formed among a set of nodes, there is a need for the development of realistic, generic and comprehensive mobility and signal propagation models. In this paper we propose the design of a mobility and signal propagation model that can be used in simulations to produce realistic network scenarios. Our model allows the placement of obstacles that restrict movement and signal propagation. Movement paths are constructed as voronoi tessellations with the corner points of these obstacles as voronoi sites. Our mobility model also introduces a signal propagation model that emulates properties of fading in the presence of obstacles. As a result, we have developed a complete environment in which network protocols can be studied on the basis of numerous performance metrics. Through simulation, we show that the proposed mobility model has a significant impact on network performance, especially when compared to other mobility models. In addition, we also observe that the performance of ad hoc network protocols is effected when different mobility scenarios are utilized. 1
Recent advances in mobility modeling for mobile ad hoc network research
 In Proc. of the ACM Southeast Regional Conf
, 2004
"... In this paper, we survey recent advances in mobility modeling for mobile ad hoc network research. The advances include some new mobility models and analysis of older mobility models. First we classify mobility models into three categories according to the degree of randomness. We introduce newly pro ..."
Abstract

Cited by 35 (1 self)
 Add to MetaCart
(Show Context)
In this paper, we survey recent advances in mobility modeling for mobile ad hoc network research. The advances include some new mobility models and analysis of older mobility models. First we classify mobility models into three categories according to the degree of randomness. We introduce newly proposed mobility models in each of these categories. Next we discuss analysis for existing mobility models. We describe the analysis work in three parts. The first part is the statistical properties of the most widely used Random Waypoint Model. The second part describes the mobility metrics that aim to capture the characteristics of different mobility patterns. The last part is the impact of mobility models on the performance of protocols. We also describe some possible future work.
Random waypoint mobility model in cellular networks,” Wireless Networks
, 2007
"... Abstract. In this paper we study the socalled random waypoint (RWP) mobility model in the context of cellular networks. In the RWP model the nodes, i.e., mobile users, move along a zigzag path consisting of straight legs from one waypoint to the next. Each waypoint is assumed to be drawn from the u ..."
Abstract

Cited by 20 (4 self)
 Add to MetaCart
(Show Context)
Abstract. In this paper we study the socalled random waypoint (RWP) mobility model in the context of cellular networks. In the RWP model the nodes, i.e., mobile users, move along a zigzag path consisting of straight legs from one waypoint to the next. Each waypoint is assumed to be drawn from the uniform distribution over the given convex domain. In this paper we characterise the key performance measures, mean handover rate and mean sojourn time from the point of view of an arbitrary cell, as well as the mean handover rate in the network. To this end, we present an exact analytical formula for the mean arrival rate across an arbitrary curve. This result together with the pdf of the node location, allows us to compute all other interesting measures. The results are illustrated by several numerical examples. For instance, as a straightforward application of these results one can easily adjust the model parameters in a simulation so that the scenario matches well with, e.g., the measured sojourn times in a cell.
Eventdriven, rolebased mobility in disaster recovery networks
 In CHANTS ’07: Proceedings of the second ACM workshop on Challenged networks
, 2007
"... One of the most important tools in understanding the complex characteristics of disaster recovery networks is simulation. While many mobility models exist for simulating ad hoc networks, they do not realistically capture the behavior of objects in disaster scenarios. We propose a high level event & ..."
Abstract

Cited by 17 (5 self)
 Add to MetaCart
(Show Context)
One of the most important tools in understanding the complex characteristics of disaster recovery networks is simulation. While many mobility models exist for simulating ad hoc networks, they do not realistically capture the behavior of objects in disaster scenarios. We propose a high level event & rolebased mobility paradigm in which objects’ movement patterns are caused by environmental events. The introduction of roles allows different objects to uniquely and realistically react to events. For instance some roles, such as civilian, may flee from events, whereas other roles, such as police, may be attracted to events. Furthermore, to incorporate reaction from multiple events in a realistic fashion, we propose a lowlevel gravitybased mobility model in which events apply forces to objects. Simulation results show that our disaster mobility paradigm coupled with our gravitational mobility model creates a network topology that differs from the popular Random Walk mobility model. This new disaster mobility model opens up the door for more realistic simulation of communication and routing protocols for disaster recovery networks.