The IMPORTANT framework for analyzing the Impact of Mobility on Performance Of RouTing protocols for Adhoc NeTworks

doi:10.1016/S1570-8705(03)00040-4

Ad Hoc Networks

Volume 1, Issue 4, November 2003, Pages 383-403

https://doi.org/10.1016/S1570-8705(03)00040-4 Get rights and content

Abstract

A Mobile Ad hoc Network (MANET) is a collection of wireless mobile nodes forming a temporary network without using any existing infrastructure. Since not many MANETs are currently deployed, research in this area is mostly simulation based. Random Waypoint is the commonly used mobility model in these simulations. Random Waypoint is a simple model that may be applicable to some scenarios. However, we believe that it is not sufficient to capture some important mobility characteristics of scenarios in which MANETs may be deployed. Our framework aims to evaluate the impact of different mobility models on the performance of MANET routing protocols. We propose various protocol independent metrics to capture interesting mobility characteristics, including spatial and temporal dependence and geographic restrictions. In addition, a rich set of parameterized mobility models is introduced including Random Waypoint, Group Mobility, Freeway and Manhattan models. Based on these models several ‘test-suite’ scenarios are chosen carefully to span the metric space. We demonstrate the utility of our test-suite by evaluating various MANET routing protocols, including DSR, AODV and DSDV. Our results show that the protocol performance may vary drastically across mobility models and performance rankings of protocols may vary with the mobility models used. This effect can be explained by the interaction of the mobility characteristics with the connectivity graph properties. Finally, we attempt to decompose the reactive routing protocols into mechanistic “building blocks” to gain a deeper insight into the performance variations across protocols in the face of mobility.

Introduction

A Mobile Ad hoc NETwork (MANET) is a collection of wireless nodes communicating with each other in the absence of any infrastructure. Classrooms, battlefields and disaster relief activities are a few scenarios where MANETs can be used. MANET research is gaining ground due to the ubiquity of small, inexpensive wireless communicating devices. Since, not many MANETs have been deployed, most of this research is simulation based. These simulations have several parameters including the mobility model and the communicating traffic pattern. In this paper, we focus on the impact of mobility models on the performance of MANET routing protocols. We acknowledge that the communicating traffic pattern also has a significant impact on the routing protocol performance and merits a study on its own. However, as in most studies in this area, in order to isolate the effect of mobility, we fix the communicating traffic pattern to consist of randomly chosen source–destination pairs with long enough session times.

Mobility pattern, in many previous studies was assumed to be Random Waypoint. In the current network simulator (ns-2) distribution, the implementation of this mobility model is as follows: at every instant, a node randomly chooses a destination and moves towards it with a velocity chosen uniformly randomly from [0,V_max], where V_max is the maximum allowable velocity for every mobile node [1]. Most of the simulations using the Random Waypoint model are based on this standard implementation. For the rest of the paper, we refer to this basic implementation as the Random Waypoint model.

In the future, MANETs are expected to be deployed in myriads of scenarios having complex node mobility and connectivity dynamics. For example, in a MANET on a battlefield, the movement of the soldiers will be influenced by the commander. In a city-wide MANET, the node movement is restricted by obstacles or maps. The node mobility characteristics are very application specific. Widely varying mobility characteristics are expected to have a significant impact on the performance of the routing protocols like DSR [5], DSDV [6] and AODV [7]. Random Waypoint is a well-designed and commonly used mobility model, but we find it is insufficient to capture those characteristics, such as

1.
Spatial dependence of movement among nodes.
2.
Temporal dependence of movement of a node over time.
3.
Existence of barriers or obstacles constraining mobility.

In this study, we focus on the impact of the above-mentioned mobility characteristics on protocol performance. While doing so, we propose a generic framework to systematically analyze the impact of mobility on the performance of routing protocols for MANETs. This analysis attempts to answer the following questions:

1.
Whether and to what degree mobility affects routing protocol performance?
2.
If the answer to 1 is yes, why?
3.
If the answer to 1 is yes, how?

To answer Whether, the framework evaluates the performance of these routing protocols over different mobility patterns that capture some of the characteristics listed above. The mobility models used in our study include the Random Waypoint, Group Mobility [8], Freeway and Manhattan. To answer Why, we propose some protocol independent metrics such as mobility metrics and connectivity graph metrics. Mobility metrics aim to capture some of the aforementioned mobility characteristics. Connectivity graph metrics aim to study the effect of different mobility patterns on the connectivity graph of the mobile nodes. It has also been observed in previous studies that under a given mobility pattern, routing protocols like DSR, DSDV and AODV perform differently [9], [10], [11]. This is possibly because each protocol differs in the basic mechanisms or “building blocks” it uses. For example, DSR uses route discovery, while DSDV uses periodic updates. To answer How, we want to investigate the effect of mobility on some of these “building blocks” and how they impact the protocol performance as a “whole”.

In order to conduct our research and answer the above questions systematically, we propose a framework for analyzing the Impact of Mobility on the Performance Of RouTing protocols in Adhoc NeTworks (IMPORTANT). Through this framework we illustrate how modeling mobility is important in affecting routing performance and understanding the mechanism of ad hoc routing protocols. As shown in Fig. 1, our framework focuses on the following aspects: mobility models, the metrics for mobility and connectivity graph characteristics, the potential relationship between mobility and routing performance and the analysis of impact of mobility on building blocks of ad hoc routing protocols.

The rest of this paper is organized as follows. Section 2 gives a brief description of the related work and elaborates our contribution. Section 3 discusses some limitations of the Random Waypoint model and motivates part of our framework. Section 4 presents our proposed metrics to capture characteristics of mobility and the connectivity graph between the mobile nodes. Section 5 describes the mobility models used and introduces two new models, the Freeway mobility model and the Manhattan mobility model. Results of our simulation experiments are presented and discussed in Section 6. The analysis of the impact of mobility on protocol building blocks is discussed in Section 7. Finally, our conclusions from this study and planned future work are listed in Section 8.

Section snippets

Related work

Extensive research has been done in modeling mobility for MANETs. In this section, we mainly focus on experimental research in this area. This research can be broadly classified as follows based on the methodology used.

Limitations of Random Waypoint

Random Waypoint model was introduced in [9] and is among the most commonly used mobility models in the MANET research community. In this model, at every instant, each mobile node chooses a random destination and moves towards it with a speed uniformly distributed in [0,V_max], where V_max is the maximum allowable speed for a node. After reaching the destination, the node stops for a duration defined by the “pause time” parameter. After this duration, it again chooses a random destination and

Metrics

To quantitatively and qualitatively analyze the impact of mobility on routing protocol performance, we make use of several protocol independent metrics and protocol performance metrics. The protocol independent metrics attempt to extract the characteristics of mobility and the connectivity graph between the mobile nodes. These metrics are then used to explain the impact of mobility on the protocol performance metrics. Those metrics can be broadly classified as

1.
Mobility metrics.
2.
Connectivity graph

Mobility models

As mentioned in Section 1, Random Waypoint does not seem to capture the mobility characteristics of spatial dependence, temporal dependence and geographic restrictions. In the previous section, we defined mobility metrics that either qualitatively or quantitatively define these characteristics. To thoroughly study the effect of mobility on MANET protocol performance, we seek to evaluate the protocols over a rich set of mobility models that span the design space of the mobility metrics. Thus,

Experiments

As a first step, we wanted to validate if our proposed metrics differentiate the mobility models. Once this was done, we focused on answering the following questions: Whether mobility affects protocol performance?, if yes, we attempt to answer the questions Why? and How? mentioned in Section 1.

How mobility affects protocol performance? Analysis of building blocks

Unlike the conventional evaluation studies [16], [17], [18], we pursue our analysis beyond the “whole protocol” level and attempt to answer How mobility affects protocol performance by looking into the “parts” that constitute the MANET routing protocols. We propose an approach to systematically decompose a protocol into its functional mechanistic “building blocks”. Each building block can be thought of as a parameterized “black box”. The parameter settings define the behavior of each block,

Conclusions and future work

In this paper, we proposed a framework to analyze the impact of mobility pattern on routing performance of mobile ad hoc network in a systematic manner. In our study, we observe that the mobility pattern does influence the performance of MANET routing protocols. This conclusion is consistent with the observation of previous studies. But unlike previous studies that compared different ad hoc routing protocols, there is no clear winner among the protocols in our case, since different mobility

Uncited references

[2], [3], [4].

Fan Bai received B.S. in Automation Engineering from Tsinghua University, Beijing, China in 1999. Since 1999, he has been pursuing the Ph.D. degree at Department of Electrical Engineering at University of Southern California, California.

His current research interests include protocol design for mobile ad hoc network and wireless sensor network. URL: http://www-scf.usc.edu/~fbai.

References (19)

L. Breslau et al.
Advances in network simulation
IEEE Computer
(2000)
F. Bai, N. Sadagopan, A. Helmy, Important: a framework to systematically analyze the impact of mobility on performance...
N. Sadagopan, F. Bai, B. Krishnamachari, A. Helmy, Paths: analysis of path duration statistics and their impact on...
F. Bai, N. Sadagopan, A. Helmy, Brics: a building-block approach for analyzing routing protocols in ad hoc networks––a...
D.B. Johnson et al.
DSR: the dynamic source routing protocol for multi-hop wireless ad hoc networks
C.E. Perkins, P. Bhagwat, Highly dynamic destination sequenced distance vector routing (DSDV) for mobile computers, in:...
C. Perkins, Ad hoc on demand distance vector (AODV) routing, internet draft,...
X. Hong, M. Gerla, G. Pei, C.-C. Chiang, A group mobility model for ad hoc wireless networks, in: ACM/IEEE MSWiM,...
J. Broch, D.A. Maltz, D.B. Johnson, Y.-C. Hu, J. Jetcheva, A performance comparison of multi-hop wireless ad hoc...

There are more references available in the full text version of this article.

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His current research interests include protocol design for mobile ad hoc network and wireless sensor network. URL: http://www-scf.usc.edu/~fbai.

Narayanan Sadagopan is a Ph.D. student in the Computer Science Department at the University of Southern California (USC) since Summer 2001. He completed his M.S. in Computer Science at USC (2001) and B.E. in Computer Science and Engineering from National Institute of Technology (NIT), Trichy, India (1998).

He is interested in mathematical modeling and algorithms. Currently, he is applying these techniques to routing in adhoc and sensor networks. URL: http://www-scf.usc.edu/~nsadagop.

Ahmed Helmy received his Ph.D. in Computer Science (1999), M.S. in Electrical Engineering (1995) from the University of Southern California, M.S. in Engineering Mathematics (1994) and B.S. in Electronics and Communications Engineering (1992) from Cairo University, Egypt.

Since 1999, he has been an Assistant Professor of Electrical Engineering at the University of Southern California. In 2002, Dr. Helmy received the National Science Foundation (NSF) CAREER Award, in 2000 he received the USC Zumberge Award, and in 2002 he received the best paper award from the IEEE/IFIP International Conference on Management of Multimedia Networks and Services (MMNS). In 2000, he founded––and is currently directing––the wireless networking laboratory at USC. His current research interests lie in the areas of protocol design and analysis for mobile ad hoc and sensor networks, mobility modeling, design and testing of multicast protocols, IP micro-mobility, and network simulation. URL: http://ceng.usc.edu/~helmy.

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