Random Waypoint Model Research Articles

Influence of node mobility on virus spreading behaviors in multi-hop network

Multi-hop network has received growing attention recently with the widely use of wireless network communication technology. At the same time, the security of multi-hop network is facing more serve challenges. Unfortunately, classic techniques for computer virus spreading model cannot be applied to multi-hop network because of ignoring dynamic topology of network. In this paper, classic susceptible-infected (SI) model, susceptible-infected-susceptible (SIS) model and susceptible-infected-removed (SIR) model are applied to multi-hop network based on random way-point (RWP) model, and contact duration of virus is introduced. Virus spreading behaviors are examined through contact duration of virus, communication radius of node, distribution density of node, and the number of initial infected nodes. Simulation results show that node mobility has significant effect on virus spreading behaviors. In particular, a special node speed that can lead network to appear the fastest-spreading virus phenomenon is found. The special speed is approximately equal to the ratio of communication radius of node to contact duration of virus. Distribution density of node and the number of initial infected nodes almost do not affect the special speed.

BETA random waypoint mobility model for wireless network simulation

It is widely known that the instantaneous average node speed for the random waypoint (RWP) mobility model may not reach a steady state regime due to velocity gradual decaying which can cause inaccurate results in simulations and communication protocol validations for wireless networks. This paper presents a modification to the RWP model, in which we propose to choose node speeds from a BETA(α, β) distribution, demonstrating analytically and by simulations that depending on the values of α and β parameters the instantaneous average node speed and consequently other important network metrics, like control overhead and number of dropped data packets may reach (or not) a steady state regime. Therefore, by allowing α and β to vary, a multitude of probability distributions for speed choice is obtained and the resulting limiting state behavior for the mobility model can straightforwardly be determined, offering to the research community a generalized BETA random waypoint mobility model. Accordingly, the generic analytical closed form for the instantaneous average node velocity V¯ as Vmin → 0 is obtained as a function of α and β to be given by limVmin→0V¯=Vmaxα−1β+α−1 in which Vmin and Vmax are the minimum and maximum velocities, respectively, that a node can select.

A Robust Security Algorithm for VANETs

The VANETs carry several security considerations. One in every of the popular and dangerous attacks is launched within the variety of Sybil, connectivity holes or cut-up attack, wherever associated in Nursing assaulter inserts a faux position inside within the cluster. The inserted faux node data is used by the hackers within the case of inconsiderate driver, traffic jams, selective collisions and different similar dangerous things. To avoid such things the VANETs should be protected against such attacks. During this paper, a completely unique answer has been projected to beat the Sybil and cut-up attacks on the VANETs. The new answer is capable of police work the faux data injections by confirmatory the VANET node behavior within the cluster. The behavior of the node includes the direction, speed and pattern. The projected model has been developed mistreatment the random waypoint model. The random waypoint model has been compared against the point of reference cluster model. The experimental results have shown the effectiveness of the projected model and also shows that RWPM is better than RPGM.

Applying location estimation for reliable routing in tactical unmanned ground vehicle networks

An unmanned ground vehicle (UGV) network operates as an ad hoc autonomous tactical network. In this paper, we study the deployment of a UGV network and its ability to use location estimation to provide reliable data forwarding. This analysis involves (1) location estimation to obtain realistic estimates of the node’s (UGV) spatial positions and (2) real-time path planning to obtain reliable routing among nodes using the estimates of the node positions. Conventional approaches commonly use the popular Random Waypoint (RWP) model (or its variants) as the mobility model. The RWP approach uses randomly selected node positions and has no way to cope with nodes moving in and out of transmission range. These deficiencies cause the route reliability to suffer. Our approach (1) uses an Extended Kalman Filter (EKF) for node mobility/location estimation and (2) uses a modified Ad Hoc On Demand Distance Vector (AODV) algorithm for route selection using a new routing parameter called contact time. We refer to this combined approach as the AODV-LocPred algorithm. We compare the AODV-LocPred algorithm with AODV using the RWP model. This is referred to as AODV-RWP. Our simulations show that the AODV-LocPred algorithm significantly outperforms the AODV-RWP algorithm in terms of packet delivery ratio (PDR), because it provides realistic node position estimates and it copes in a reasonable way with nodes moving in and out of transmission range. However, the AODV-LocPred incurs an increase in end-to-end delay. Nonetheless, we expect that in many real-world settings, this tradeoff is acceptable.

Energy Efficiency and Contact Opportunities Tradeoff in Opportunistic Mobile Networks

To discover neighbor nodes, nodes in opportunistic mobile networks (OppNets) have to probe their environment continuously. This can be an extremely energy-consuming process. If nodes probe very frequently, a lot of energy will be consumed in the contact probing process and might be inefficient. On the other hand, infrequent contact probing might cause nodes to miss many of their contacts. Therefore, there exists a tradeoff between energy efficiency and contact opportunities in OppNets. To investigate this tradeoff, we first propose a model to investigate the contact probing process based on the random-waypoint model and obtain the expressions of the single detecting probability and the double detecting probability. Moreover, we also demonstrate that among all contact probing strategies with the same average probing interval, which do not have preknowledge of the contact process, the strategy that probes at a constant interval performs better than any arbitrary probing strategy in expectation in the single contact probing process. Then, extensive simulations are conducted to validate the correctness of our proposed model. Finally, based on the proposed model, we analyze the tradeoff between energy efficiency and the total number of effective contacts in the single and double contact probing processes. Our results show that the total number of effective contacts in the single and double contact probing processes has a lower bound and an upper bound, and the good tradeoff points are obviously different when the speed of nodes is different.

ELDP: Extended Link Duration Prediction Model for Vehicular Networks

Link duration between two vehicles is considered an important quality of service metric in designing a network protocol for vehicular networks. There exist many works that study the probability density functions of link duration in a vehicular network given various vehicle mobility models, for example, the random waypoint model. None of them, however, provides a practical solution to estimating the link duration between two vehicles on the road. This is in part because link duration between vehicles is affected by many factors including the distance between vehicles, their turning directions at intersections, and the impact of traffic lights. Considering these factors, we propose the extended link duration prediction (ELDP) model which allows a vehicle to accurately estimate how long it will be connected to another vehicle. The ELDP model does not assume that vehicles follow certain mobility models; instead, it assumes that a vehicle's velocity follows the Normal distribution. We validate the ELDP model in both highway and city scenarios in simulations. Our detailed simulations illustrate that relative speed between vehicles plays a vital role in accurately predicting link duration in a vehicular network. On the other hand, we find that the turning directions of a vehicle at intersections have subtle impact on the prediction results.

User Mobility Evaluation for 5G Small Cell Networks Based on Individual Mobility Model

With small cell networks becoming core parts of the fifth generation (5G) cellular networks, it is an important problem to evaluate the impact of user mobility on 5G small cell networks. However, the tendency and clustering habits in human activities have not been considered in traditional user mobility models. In this paper, human tendency and clustering behaviors are first considered to evaluate the user mobility performance for 5G small cell networks based on individual mobility model (IMM). As key contributions, user pause probability, user arrival, and departure probabilities are derived in this paper for evaluating the user mobility performance in a hotspot-type 5G small cell network. Furthermore, coverage probabilities of small cell and macro cell BSs are derived for all users in 5G small cell networks, respectively. Compared with the traditional random waypoint (RWP) model, IMM provides a different viewpoint to investigate the impact of human tendency and clustering behaviors on the performance of 5G small cell networks.

Connection times in large ad-hoc mobile networks

We study connectivity properties in a probabilistic model for a large mobile ad-hoc network. We consider a large number of participants of the system moving randomly, independently and identically distributed in a large domain, with a space-dependent population density of finite, positive order and with a fixed time horizon. Messages are instantly transmitted according to a relay principle, that is, they are iteratively forwarded from participant to participant over distances smaller than the communication radius until they reach the recipient. In mathematical terms, this is a dynamic continuum percolation model. We consider the connection time of two sample participants, the amount of time over which these two are connected with each other. In the above thermodynamic limit, we find that the connectivity induced by the system can be described in terms of the counterplay of a local, random and a global, deterministic mechanism, and we give a formula for the limiting behaviour. A prime example of the movement schemes that we consider is the well-known random waypoint model. Here, we give a negative upper bound for the decay rate, in the limit of large time horizons, of the probability of the event that the portion of the connection time is less than the expectation.

Identification of the Optimum Relocalization Time in the Mobile Wireless Sensor Network using Time-Bounded Relocalization Methodology

Contrary to the static sensor network that requires one-time localization, a mobile wireless sensor network (MWSN) requires an estimation of the optimum time to retrigger the localization of the network to accurately identify the sensor location after certain movements. However, triggering relocalization at predefined time intervals without proper consideration of the dynamic movement of sensors is insubstantial and results in poor resource management. In this paper, a new algorithm called time-bounded relocalization is proposed to identify the optimum relocalization time for the entire MWSN using the time-bounded localization method based on the analysis of the sensors' mobility pattern. In the proposed algorithm, the optimum retriggering time across the entire network can be calculated in two phases: local and global relocalizations. In the first phase, an island-based clustering method is used to estimate the local relocalization time. Next, the estimated local times are then used to decide on the optimum global relocalization time based on the statistical property of the estimated local times. For these calculations, a probabilistic model of the random waypoint (RWP) is selected. The soundness of the proposed algorithm is initially validated by deriving the probabilistic model of the optimum retriggering time, and its accuracy is checked by the Cramer–Rao lower bound (CRLB). The proposed algorithm is then extensively tested by computer simulation using practical network parameters, including the number of nodes, the size of the network, and various sizes of islands, depending on the sensor mobility, to yield the respective optimum relocalization time. The simulation results show that by using the identified optimum relocalization time, the location estimation error can be reduced by up to 32% for the RWP model, as compared with the case of using fixed relocalization time.

Movement Abnormality Evaluation Model in the Partially Centralized VANETs for Prevention Against Sybil Attack

The VANETs carry many security concerns. One of the popular and dangerous attacks can be launched in the form of Sybil or Prankster attack, where an attacker inserts a fake position within in the cluster. The inserted fake node information can be utilized by the hackers in the case of selfish driver, traffic jams, selective collisions and other similar hazardous situations. To avoid such things the VANETs must be protected against such attacks. In this paper, a novel solution has been proposed to overcome the Sybil and prankster attacks on the VANETs. The new solution is capable of detecting the fake information injections by verifying the VANET node behaviour in the cluster. The behaviour of the node includes the direction, speed, pattern, etc. In case a node is found malicious, the whole cluster is reported against that node, and node is ordered to stop by the central control system. The proposed model has been developed using the random waypoint model. The random way point model is much closer to the real time VANETs. The random waypoint model has been compared against the reference point group model. The experimental results have shown the effectiveness of the proposed model.

On Delay Constrained Multicast Capacity of Large-Scale Mobile Ad Hoc Networks

This paper studies the delay constrained multicast capacity of large-scale mobile ad hoc networks (MANETs). We consider a MANET that consists of $n_{s}$ multicast sessions. Each multicast session has one source and $p$ destinations. Each source sends identical information to the $p$ destinations in its multicast session, and the information is required to be delivered to all the $p$ destinations within $D$ time-slots. Assuming the wireless mobiles move according to a 2-D independently and identically distributed mobility model, we first prove that the capacity per multicast session is $O(\min \{1, (\log p)(\log (n_{s}p)) ({{D}/{n_{s}}})^{1/2}\})$ . 1 We then propose a joint coding/scheduling algorithm achieving a throughput of $\Theta (\min \{1,{({D}/{n_{s}})}^{1/2}\})$ . Our simulation results suggest that the same scaling law also holds under random walk and random waypoint models. 1 Given non-negative functions $f(n)$ and $g(n)$ : $f(n)=O(g(n))$ means there exist positive constants $c$ and $m$ such that $f(n) \leq cg(n)$ for all $ n\geq m;~f(n)=\Omega (g(n))$ means there exist positive constants $c$ and $m$ such that $f(n)\geq cg(n)$ for all $n\geq m;~f(n)=\Theta (g(n))$ means that both $f(n)=\Omega (g(n))$ and $f(n)=O(g(n))$ hold; $f(n)=o(g(n))$ means that $\lim _{n\rightarrow \infty } f(n)/g(n)=0$ ; and $f(n)=\omega (g(n))$ means that $\lim _{n\rightarrow \infty } g(n)/f(n)=0$ .

Optimization of Heterogeneous Network Performances Based on the Signal Interferences Noise Ration(SINR)

Integration of wireless and mobile networks to new generations constitutes a heterogeneous system, this is the case of LTE and WiFi networks. In this paper, we study and analyze the optimal performances of this system regarding the SINR(Signal Interference Noise Ration), the blocking probability and the user communication loss. The user mobility is represented by random wayPoint(RWP) model and users terminals equipped with multiple accesses interfaces. We have established a Markov chain to assess and analyze the performances obtained from the heterogeneous networks system. So we have proposed an average value of the signal power emitted in down-ling voice, the blocking probability of system connections.

An Investigation on the Impact of Weather Modelling on Various MANET Routing Protocols

The objective of the work is to analyze the impact of weather conditions on different types of MANET routing protocols. The influence of weather on the performances of MANET protocols such as AODV, STAR, RIP and ZRP are compared with and without considering weather conditions. Most of the works are not considering the effect of weather, when analysing the performances of MANET protocols. The simulations are carried out using Qualnet 5.0 with 100 nodes. The mobility model used for simulation is the Random waypoint model, where each node is moving independently to reach the destination with a random velocity. The velocity of each mobile node varies from 10 m/s to 50 m/s with the weather intensity of 1000 deg/m2. The performance metrics such as end to end delay, jitter, through put and packet delivery ratio are analysed and compared. The simulation results reveals that AODV provides better throughput and high packet delivery ratio compared to other protocols under with and without considering weather. STAR protocol yields good performance with respect to end to end delay and jitter under both conditions.

IRF-NMB: Intelligent Route Formation Technique in Ad Hoc Network Using Node Mobility Behaviour

A mobile ad hoc network (MANET) is a self-configuring network of mobile devices connected with wireless link. The topology of an ad hoc network changes due to the movement of mobile hosts. In MANETs, the data packet may fail to be delivered or a route is to be established again for various reasons including packet collision, nodes movement and bad channel conditions. The proposed research work intelligent route formation technique in ad hoc networks using node mobility behaviour (IRF-NMB) modifies ad hoc on demand distance vector (AODV) to improve its performance by selecting nodes in a route to destination on the basis of past mobile behavior of nodes. The mobility behavior of nodes in proposed method is modeled using random waypoint model. The performed simulation compares packet delivery ratio versus number of nodes, packet delivery ratio versus node max speed (m/s), end to end delay versus number of nodes, end to end delay node max speed (m/s) of stability routing base on reverse AODV (Hua and Li in International conference on ICCSNT, 2011) and IRF-NMB. Simulation result shows that our scheme improves the routing protocols.

Aggregate Interference in Random Waypoint Mobile Networks

In this work, we characterize the wireless interference of a mobile ad hoc network, where the nodes move according to the Random Waypoint model. The interferers are assumed to be located within an interference region, which is defined as a circular region centered in a fixed node located in the center of the mobility scenario. The main contribution of this letter is the characterization of the aggregate interference caused to the fixed node by the mobile interferers located within the interference region. The distribution of the interference is analyzed taking into account the stochastic nature of the path loss due to the mobility of the nodes. The theoretical approach is validated through simulations, which confirm its effectiveness.

QOS - Guaranteed Neighbour Selection &Distributed Packet Scheduling Algorithm byUsing MANET Wireless Networks

The number of Wifi capable mobile devices including laptops and handheld devices (e.g., smart phone and tablet PC) has been increasing rapidly. A Mobile Ad hoc Network (MANET) is consisting of a collection of wireless mobile nodes, which form a temporary network without relying on any existing infrastructure or centralized administration. The emergence and the envisioned future of real time and multimedia applications have stimulated the need of high Quality of Service (QoS) support in wireless and mobile networking environments. The QoS support reduces end-to-end transmission delay and enhances throughput to guarantee the seamless communication between mobile devices and wireless infrastructures. we propose a QoS-Oriented Distributed routing protocol (QOD) to enhance the QoS support capability of hybrid networks. Analytical and simulation results based on the random waypoint model and the real human mobility model show that QOD can provide high QoS performance in terms of overhead, transmission delay, mobility-resilience, and scalability.

LAOF: location‐aware opportunistic forwarding scheme in mobile Ad hoc networks

AbstractDue to the high mobility of the nodes, the mobile ad hoc networks are expected to provide many opportunities for message forwarding in delay tolerant networks. Considering the typical mobility models, for example, the random waypoint (RWP) model and Manhattan model, we explore the probabilistic characteristics of the node contact provided by the mobile nodes. Following a progressive approach, we propose a location‐aware opportunistic forwarding scheme, which exploits the location information of the messages and the node mobility to conduct message forwarding. In order to provide a stable delivery ratio and avoid the extra network overhead, the message is forwarded to its destination regions or neighbor regions, which offer a better chance to reach the destination node. We construct a simulation environment, integrated with the RWP mobility trace and the Shanghai city taxis traces. Through extensive simulations, our scheme is demonstrated to outperform the best known opportunistic forwarding algorithms in terms of both delivery ratio/latency and transmission overhead. Copyright © 2014 John Wiley & Sons, Ltd.

The Impact of Rate Adaptation on Capacity-Delay Tradeoffs in Mobile Ad Hoc Networks

In this paper, we focus on the asymptotic capacity and delay, and their tradeoffs in mobile ad hoc networks (MANETs). As we all know, some fixed rate communication models such as the protocol model and the physical model have been studied in the past. However, our work aims to investigate the impact of an adaptive rate communication model on capacity-delay tradeoffs in MANETs under classical mobility models. Specifically, we adopt a well-known adaptive rate model called the generalized physical model (GphyM). The mobility of nodes is characterized by two broad classes of practical mobility models and they are hybrid random walk models and discrete random direction models. The two models generalize many mobility models studied in the literature, including the random walk, i.i.d., Brownian, and random way point models. For each mobility model, we derive the optimal delay for the optimal per-session unicast capacity (that of constant order Θ(1)) under the generalized physical model, depending on the individual parameters of mobility models. In particular, we show that for the i.i.d. model, compared with those under the protocol and physical models, the adaptive feature of link rate under the generalized physical model results in a significant decrease in the optimal delay for the optimal capacity; more precisely, both the optimal capacity and optimal delay can be simultaneously achieved, while there is no improvement for the random way-point model.

Investigation of an Analytical Model Based on Resource Factor for Vertical Handoffs

In order to optimize the utilization of limited resources, the operators have already addressed to deploy their services in heterogeneous networks integrated different Radio Access Technologies (RAT), e.g. WLAN/WiMAX/WCDMA. Vertical handoffs (VHO) as a key problem should be overcome while mobile users are moving in heterogeneous networks. In existing works, resource assignment depends on the packet’s size, which is usually defined a fix length. This paper proposes an analytical model for evaluating the VHO performance. In the model, resources are proportionally assigned to real-time services (RS) and to non realtime services (NRS) by a resource factor m, which can be defined as any value. The performances on blocking probability and on throughput are derived and evaluated with different values of m under the restriction of resources. For enhancing the effect of VHO, the Random Waypoint Model on the border (RWPB) is implemented in the simulation, which enforces the mobile users residing near the border of networks. Simulation results demonstrate that with a greater value of m, the blocking probability slightly increases while the total throughput is significantly improved.

A Novel Data Centric Information Retrieval Protocol for Queries in Delay Tolerant Networks

Information Retrieval (IR) systems aim to retrieve data that satisfies certain requirements and constitute an important service in many types of networks, including Delay/Disruption Tolerant Networks (DTNs). In current DTN based IR systems, the data that satisfies a query is assumed to be stored on a single node. Therefore, once a node receives a query in which it has the corresponding data, the query can be resolved completely. However, in scenarios where a query requires data from multiple nodes, these IR systems may fail. Henceforth, in this paper, we propose Distributed Data-Centric Information Retrieval (DDC-IR), a data centric IR system that supports all query types; e.g., continuous and complex. More importantly, it is designed specifically to operate in DTNs. It also incorporates a new packet, aka Query Reply Packet, that includes both a query and one or more replies. We show how this packet facilitates efficient query resolution and enables data centric routing. In addition, it uses caching so that nodes store popular queries that has the effect of speeding up query resolution. We have conducted an extensive simulation study to compare DDC-IR to state of the art IR systems using the popular Random Waypoint model and a trace-file containing student movements on a campus. The results show that DDC-IR is able to resolve 50 % more queries and has an 80 % lower buffer occupancy level than existing IR systems. We also tested DDC-IR in networks with varying sizes. For networks with 100 nodes, DDC-IR is able to resolve queries while current IR systems fail to resolve any queries. In particular, when the number of nodes increases, current IR systems fail to resolve any queries, whilst DDC-IR is able to resolve complex and continuous queries. The influence of the number of sub-queries on query resolution time is also studied. Specifically, when the number of sub-queries in a complex query increases from five to nine, DDC-IR uses 50 % more time to resolve a query. In comparison, prior IR systems fail to resolve any queries.