Showing papers by "Rafidah Md Noor published in 2018"

Adaptive Beaconing Approaches for Vehicular Ad Hoc Networks: A Survey

Abstract: Vehicular communication requires vehicles to self-organize through the exchange of periodic beacons. Recent analysis on beaconing indicates that the standards for beaconing restrict the desired performance of vehicular applications. This situation can be attributed to the quality of the available transmission medium, persistent change in the traffic situation and the inability of standards to cope with application requirements. To this end, this paper is motivated by the classifications and capability evaluations of existing adaptive beaconing approaches. To begin with, we explore the anatomy and the performance requirements of beaconing. Then, the beaconing design is analyzed to introduce a design-based beaconing taxonomy. A survey of the state of the art is conducted with an emphasis on the salient features of the beaconing approaches. We also evaluate the capabilities of beaconing approaches using several key parameters. A comparison among beaconing approaches is presented, which is based on the architectural and implementation characteristics. The paper concludes by discussing open challenges in the field.

A Multivariant Stream Analysis Approach to Detect and Mitigate DDoS Attacks in Vehicular Ad Hoc Networks

Abstract: Vehicular Ad Hoc Networks (VANETs) are rapidly gaining attention due to the diversity of services that they can potentially offer. However, VANET communication is vulnerable to numerous security threats such as Distributed Denial of Service (DDoS) attacks. Dealing with these attacks in VANET is a challenging problem. Most of the existing DDoS detection techniques suffer from poor accuracy and high computational overhead. To cope with these problems, we present a novel Multivariant Stream Analysis (MVSA) approach. The proposed MVSA approach maintains the multiple stages for detection DDoS attack in network. The Multivariant Stream Analysis gives unique result based on the Vehicle-to-Vehicle communication through Road Side Unit. The approach observes the traffic in different situations and time frames and maintains different rules for various traffic classes in various time windows. The performance of the MVSA is evaluated using an NS2 simulator. Simulation results demonstrate the effectiveness and efficiency of the MVSA regarding detection accuracy and reducing the impact on VANET communication.

Shapely Value Perspective on Adapting Transmit Power for Periodic Vehicular Communications

Abstract: Periodic beacons in vehicular ad hoc networks are transmitted with high message frequency to achieve the higher level of awareness required for the vehicular safety applications. Currently, the existing 10-MHz control channel in the dedicated short range communication (DSRC) standard is not compliant with the communication requirements in vehicular safety applications, i.e., the stipulated amendments in the DSRC offer little relief to congestion caused by the periodic beacon transmissions on the control channel, which adversely affects the message reception. In this paper, we seek to address the problem of congestion with a transmit power adaptation approach, based on the principles of cooperative game theory. The proposed approach, Adaptive transmit power Cooperative Congestion Control (AC3), is designed to allow vehicles to select their transmit power autonomously with respect to their local channel congestion. Since the number of neighbours of each vehicle and their corresponding transmit power levels vary, AC3 requires that each vehicle reduces its transmit power fairly during congestion. Explicitly, the proposed approach introduces the notion of marginal contributions of vehicles towards congestion and determines a fair power decrease for vehicles using a shapely value system model. This model requires the vehicles with the highest marginal contributions to reduce the most transmit power and vice versa. The simulation results demonstrate the utility of the proposed approach (i.e., capability to determine fair power decrease for an effective congestion control).

Coverage Differentiation Based Adaptive Tx-Power for Congestion and Awareness Control in VANETs

Abstract: The use of Information and Communication Technology (ICT) as a copilot for the drivers has a potential to improve traffic safety and efficiency. A key challenge in integrating ICT in vehicular networks is to provide the mechanisms for the delivery of safety messages called beacons. In particular, finding the trade-off between providing sufficient coverage and controlling channel congestion remains the focus in the stipulated amendments for safety message transmissions. In this paper, we handle this trade-off by proposing a Multi-metric Power Control (MPC) approach, which uses application requirements and channel states to determine a transmit power for safety messages. The MPC gives a best-effort approach to satisfy the coverage range requirement of a message as specified by the application. Moreover, the concept distinguishes among message types to provide coverage differentiation. We show that the best-effort approach of providing coverage for different messages can control congestion and as a result improve awareness by minimizing beacon collisions. The performance analysis of MPC using discrete event simulation confirms its practicality.

Towards a Better Approach for Link Breaks Detection and Route Repairs Strategy in AODV Protocol

Abstract: This paper describes a parameterized approach to the Ad Hoc On-Demand Distance Vector (AODV) routing protocol using a network-simulator 2 (ns2). By utilizing two AODV’s protocol functions, which are HELLO messages and local route repair, we explore the more flexible approach on these two important functions, rather than a fixed setting within the default AODV protocol. HELLO message is used to detect the broken link, while the local route repair in AODV is used to fix and discover alternative routes in the event of route failure. In this paper, two functions to optimize AODV performance have been utilized. The first is link break detection time ( ), using the HELLO message to detect link failure, and the second is link break position parameter ( ) for AODV’s local route repair. The results show that the default AODV setting does not yield the best results for most defined network scenarios. In some cases, improvement compared to the default setting can be as high as 38%, for local route repair strategies. This paper presents a potential flexible and parameterized approach for dealing with link breaks and route repairing strategies for AODV protocol.

Handover Schemes for Vehicular Ad-Hoc Networks Over Long Term Evolution Advanced: A Survey

Abstract: Next generation Vehicular Ad Hoc Network (VANET) needs seamless connectivity with high level of quality of services (QoS) and high data rates services. The complexity of VANET raises concern about the QoS and the reliability of the communication handover which refer to the connectivity and operation of conveying an ongoing call or data session between Vehicles to Vehicles (V2V) and Vehicles to Infrastructure (V2I) in VANET communication mode. This communication faces a huge challenge. The vehicles are moving so fast and highly dynamic that may cause frequent handover which may cause signal delay and communication loss. This paper provides an up-to-date literature of handover schemes for VANET over LTE-A wireless network. A discussion on thumbnail of the key decision parameters to be used in the handover algorithm and comparative summary of selected scheme for VANET over LTE-A concludes this work. This study, thus contributes to the understanding of the available options and gaps for further studies and standardization activities to this area of research.

Effect of Increasing Number of Nodes on Performance of SMAC, CSMA/CA and TDMA in MANETs

Abstract: The importance of Wireless Sensor Network (WSN) increases due to deployment for geographical, environmental and surveillance purpose in war fields. WSN facing several challenges due to its complex nature including key problems, such as routing and medium access control protocols. Several approaches were proposed for the performance evaluation of WSN on the basis of these issues due to the fact that MAC layer access protocols have a great impact on the performance of WSN. In this paper, we investigated the performance evaluation of three well known MAC Access protocols, i.e. sensor medium access control protocol (SMAC), carrier sense multiple access with collision avoidance (CSMA/CA), and time division multiple access (TDMA) over adhoc on demand distance vector (AODV) routing protocol. The number of simulation scenarios were carried out by using NS- 2, the simulation metrics used are throughput, end-to-end delay and energy consumed. Simulation results showed that SMAC out perform CSMA/CA and TDMA by consuming less energy, less end to end delay and high throughput due to contention based approach to access the medium for transmission.

Quality of Service Impact on Deficit Round Robin and Stochastic Fair Queuing Mechanism in Wired-cum-Wireless Network

Abstract: The deficient round robin (DRR) and stochastic fair queue (SFQ) are the active queue mechanism (AQM) techniques. These AQM techniques play important role in buffer management in order to control the congestion in the wired-cum-wireless network by dropping packets during the buffer overflow or near to overflow. This research study focus on the performance evaluation of the DRR and SFQ using different scenarios such as increasing number of node scenario, pause time scenario and mobility scenario. We evaluate the performance of DRR and SFQ based on two parameters such as average packet delay and average packet dropped. In case of increasing number of nodes, the SFQ has outperformed than DRR by having comparatively low per packet delay. DRR has higher packet dropped ratio as compare to SFQ. In mobility and pause time scenario, SFQ has less per packet delay while DRR has less packet dropped ratio These results revealed that DRR performance was affected by an increase in the number of nodes in a network. The DRR send the packet in a round-robin fashion without caring about the bandwidth of a path due to which the packet dropped ratio was high. On another hand, the SFQ has comparatively outperformed in all scenarios by having less per packet delay. SFQ become aggressive by dropping more data packets during buffer overflow. In short, SFQ will be preferred for a network where the congestion occurred more frequently.

Towards Energy-Efficient RF-Enabled Sensor Networks in Internet of Things

Abstract: A crucial conduct norm for a sensor network is to avoid network failures and packet drop. One of the other essential requirements is to effectively manage the energy levels of the nodes according to the states of the operation required for an application. This paper proposes an energy management model with the aim of allowing energy optimization of Radio Frequency (RF) enabled Sensor Networks (RSN) through Energy Harvesting (EH) and Energy Transfer (ET) techniques. The harvested and transferred energy is used by the RSN tags to maintain the energy levels of the network and prevent dead state of a node. It is observed that these Energy Management (EM) techniques are different from the existing solutions in the literature, where managing the energy consumption by the transceivers and the radio is tedious in integrated systems of sensors and tags. Stochastic Backscattering Algorithm (SBA) based on the trade-off between EH rate and transmission range is also proposed. Performance analysis of the proposed EM model is carried out by characterizing the RSN nodes using Semi Markov Decision Process (SMDP). Numerical results show that through RF-based EH and SBA based ET, the lifetime of the network can be improved by around 25%, comparatively to conventional sensor networks. The results are quantified empirically for Internet of Things (IoT) contexts in terms of energy costs, lifetime of sensors and successful packet transmission.

Impact of multipath fading on spectrum sensing in vehicular communication environment

Abstract: Dynamic spectrum access (DSA) has received much attention in research community recently. DSA is the concept in which communication devices of unlicensed users are allowed to access underutilized spectrum in licensed frequency bands. DSA relies on cognitive radio (CR) technology to identify the free spectrum bands in licensed channels through spectrum sensing. In vehicular communications, spectrum sensing is affected by the speed of vehicles, multipath fading and shadowing. In this paper, we show the impact of fading on spectrum sensing in vehicular communications. Understanding how the fading environment affects spectrum sensing will help in developing sensing techniques that can prevent interference in licensed channels while allowing for utmost reuse of radio frequency through DSA.