Cognitive radio-enabled Internet of Vehicles (IoVs): a cooperative spectrum sensing and allocation for vehicular communication

Internet of Things (IoTs) era is expected to empower all aspects of Intelligent Transportation System (ITS) to improve transport safety and reduce road accidents. US Federal Communication Commission (FCC) officially allocated 75MHz spectrum in the 5.9GHz band to support vehicular communication which many studies have found insufficient. In this paper, we studied the application of Cognitive Radio (CR) technology to IoVs in order to increase the spectrum resource opportunities available for vehicular communication, especially when the officially allocated 75MHz spectrum in 5.9GHz band is not enough due to high demands as a result of increasing number of connected vehicles as already foreseen in the near era of IoTs. We proposed a novel CR Assisted Vehicular NETwork (CRAVNET) framework which empowers CR enabled vehicles to make opportunistic usage of licensed spectrum bands on the highways. We also developed a novel co-operative three-state spectrum sensing and allocation model which makes CR vehicular secondary units (SUs) aware of additional spectrum resources opportunities on their current and future positions and applies optimal sensing node allocation algorithm to guarantee timely acquisition of the available channels within a limited sensing time. The results of the theoretical analyses and simulation experiments have demonstrated that the proposed model can significantly improve the performance of a cooperative spectrum sensing and provide vehicles with additional spectrum opportunities without harmful interference against the Primary Users (PUs) activities

Timely and reliable packets delivery over Internet of Vehicles (IoVs) for road accidents prevention: a cross-layer approach

With the envisioned era of Internet of Things (IoTs), all aspects of Intelligent Transportation Systems (ITS) will be connected to improve transport safety, relieve traffic congestion, reduce air pollution, enhance the comfort of transportation and significantly reduce road accidents. In IoVs, regular exchange of current position, direction, velocity, etc., enables mobile vehicles to predict an upcoming accident and alert the human drivers in time or proactively take precautionary actions to avoid the accident. The actualization of this concept requires the use of channel access protocols that can guarantee reliable and timely broadcast of safety messages. This paper investigates the application of network coding concept to increase content of every transmission and achieve improved broadcast reliability with less number of retransmission. In particular, we proposed Code Aided Retransmission-based Error Recovery (CARER) scheme, introduced an RTB/CTB handshake to overcome hidden node problem and reduce packets collision rate. In order to avoid broadcast storm problem associated with the use of RTB/CTB packet in a broadcast transmission, we developed a rebroadcasting metric used to successfully select a vehicle to rebroadcast the encoded message. The performance of CARER protocol is clearly shown with detailed theoretical analysis and further validated with simulation experiments

Use of Information Centric Network (ICN) as a viable Alternative to Traditional IP Network in Forwarding Mechanism: A Practical Approach to Preventing DoS using Bloom Filter Packet Forwarding

This paper focuses on identifying the benefits of using ICN network as an alternative to forwarding mechanism in place of the traditional IP network. The ICN network uses an In-packet Bloom filter as the forwarding identifier, where a complete analysis of the false positive probability is carried out. The formulas used in the false positive analysis include the classical formula, Bose formula and the experimental formula. However, this work does not involve the actual implementation of the Bloom filters on the router, but rather an explanation of the possibility is given. In the experimental program, we used MATLAB to generate a set of links and encode them as Bloom filters and used a function known as setdiff, which extracts the number of links to be tested from the actual links array. Keywords: Information Centric Network (ICN), IP Network, DoS, DDoS, TCP/IP Protocol Suite

Improved QoS Support for WiMAX Networks: A Survey

Quality of Service (QoS) is considered as the backbone of any Broadband media access network of which WiMAX is not an exception. Immense work is being carried out in the academia in this area. The goal is to come up with improved QoS to support different traffics in WiMAX network. This work presents a survey of the various current states-of-the-art QoS schemes that could be utilised to realise a guaranteed QoS necessary for effective general high WiMAX access network performance. We concentrate on three approaches. The approaches include Hierarchical Scheduling Framework for QoS in WiMAX point-to-point Networks, this approach divides scheduling scheme into three different Tiers. Others are Cross-layer Optimization Framework and Resource Allocation for Improved QoS in WiMAX; and On-demand Bandwidth Allocation for WiMAX. Keywords: WiMAX, QoS, Scheduling, Broadband, Bandwidth, Throughput

Investigating the QoS of Voice over IP using WiMAX Access Networks in a Campus Network

VoIP is a very rapid evolving communication technology which supports transportation of voice data via IP based networks. In parallel, IEEE 802.16e standard based WiMAX is a new emerging access technology and the first generation of 4G broadband access wireless technology with an enhanced in-built quality of service (QoS) provision with many benefits including cost reduction, high quality as well as other value added network service solutions especially for communications Service Providers with emphasis on real time services. WiMAX promises manifold benefits in terms of optimal network performance across a long distance in contrast to other wireless technologies such as Wi-Fi and 3G cellular technologies. Hence, this research attempts to identify some of the network performance parameters that Service Providers will focus on to develop a VoIP over WiMAX communication tool that will serve as a voice communication broadband replacement technology to old circuit-switch voice communication. This study adopted a simulation-based network performance analysis to investigate the effects of the application of different voice encoder schemes on QoS of VoIP system deployed with IEEE 802.16e standard WiMAX network. Through different network simulation experiments using realistic network scenarios in OPNET environment, this research provided an in-depth network performance comparative analysis of VoIP over WiMAX using performance parameters which indicate QoS such as voice jitter, voice packet ETE delay, packet-sent-packet-received, WiMAX network delay, voice packet delay variation and throughput. The obtained simulation experiment results indicated that choice of suitable codec scheme can affect the QoS of VoIP traffic over WiMAX network. The results also indicated that the choice of suitable voice encoder scheme with a small number of voice frame-size per packet have a significant impact over VoIP traffic performance when deployed with WiMAX access technology. Keywords: WiMAX, QoS, End-to-End delay, Jitter, IEEE 802.16e, PSTN, OPNET, Simulation, Wi-Fi, Code

Reliable and enhanced cooperative cross-layer medium access control scheme for vehicular communication

In an unreliable cluster-based, broadcast vehicular network setting, we investigate the transmission reliability and throughput performance of random network coding (RNC) as a function of the percentage of packet generation rate and transmit power to noise ratio. In the paper, a novel scheme called reliable and efficient cooperative cross-layer MAC (RECMAC) is proposed. The proposed scheme consists of a source vehicle broadcasting packets to a set of receivers (i.e. one-to-many) over independent broadcast erasure channels. The source vehicle performs RNC on N packets and broadcasts the encoded message to a set of receivers. In each hop, several vehicles form a cluster and cooperatively transmit the encoded or re-encoded packet. The combination of RNC, cluster based, and cooperative communications enables RECMAC to optimally minimize data redundancy, which means less overhead, and improve reliability as opposed to coding-based solutions. Theoretical analyses and simulation results show that under the same conditions RECMAC scheme can achieve improved performance in terms of transmission reliability and throughput

Denial of Service (DoS) in Internet Protocol (IP) Network and Information Centric Network (ICN): An Impediment to Network Quality of Service (QoS).

This paper compares and analyses the Denial-of-Service attacks in the two different Network architectures. The two architectures are based on different routing approaches: Hop-by-Hop IP routing and source-routing using Bloom filters. In Hop-by-Hop IP routing, the packet header contains the address, and the route is decided node by node. Forwarding in this method requires a node to have a routing table which contains the port through which the packet should traverse depending on the address of the destination. Instead in source-routing, the forwarding identifier is encoded with the path a packet should take and it is placed in the packet header. The forwarding identifier in this approach does not require a forwarding table for look ups like the IP routing; it relies on Line Speed Publish/Subscribe (LIPSIN) forwarding solution that focuses on using named links not nodes or interfaces. The forwarding identifier encompasses a set of Link ID’s which specifies the path to the recipient and they are encoded in a Bloom filter. The In-packet Bloom filters serve as both path selectors and as capabilities, and they are generated dynamically. However, this thesis is going to focus on the latter network technology by looking at both its benefits and drawbacks as well as analysing the possibilities of having a Denial of service attack. Keywords: DoS, DDoS, TCP/IP Protocol Suite, ICMP flood, E-mail Bomb, Ping of Death, TCP and UD

Comparative Analysis of QoS Guarantee on IEEE 802.11e and IEEE 802.11g Wireless Local Area Networks

For this project, we propose to compare the 802.11g and the 802.11e Wireless Local Area Networks (WLANs). The 802.11g WLAN standards are good for data applications. However, the 802.11g standard is not well-equipped to deal with the intended delay and bandwidth requirements of multimedia applications, such as video and voice over wireless IP. For this reason, an approved amendment (802.11e) was added to the IEEE 802.11 standard. The 802.11e implements Quality of Service (QoS), which enables features through changes in the Medium Access Control (MAC) layer. The performance of 802.11e will be evaluated using OPNET simulation and compared with the 802.11g WLAN standard.   Keyword: QoS, IEEE 802.11, WLAN, MAC, OPNET, WiFi, CSMA/CA

Qualitative Investigation of the Performance of Real-Time Application of IEEE 802.16e standard WiMAX Relay Networks

The ability of an application to adapt its behavior to changing network conditions depends on the available bandwidth, throughput, delay and packet loss in a network path. These are of major importance in congestion control, streaming applications, quality of service verification, relay selection and many other areas in WiMAX relay stations. Mobile WiMAX, which is based on the IEEE 802.16e standard, provides support for and enables full mobility to users. In an effort to optimize and enhance the overall network throughput, this paper will propose a mobile relay framework. WiMAX is based on the IEEE 802.16e standard, and can support various types of handovers, while allowing for full mobility from the user endpoint. Different methodologies were used to compare different aspects of WiMAX relay stations including throughput, delay, SNR and network load. OPNET modular was used to develop and measure these set of network performance metrics. To accurately measure and evaluate the aforementioned network parameters we employed techniques that were able to process large amounts of data, this aided in provision of much more informed recommendations as to the type of relay station modes that should be installed engender enhanced, improved and optimal Quality of Service (QoS) within the network perimeter. This paper measured the overall network throughput, delay, SNR and network load of relay networks comprising mainly of multimedia applications. Keywords: WiMAX, QoS, Relay Station, Simulation, Topology, Throughput, Delay, Packet Los

Advances in Vehicular Ad-hoc Networks (VANETs): challenges and road-map for future development

Recent advances in wireless communication technologies and auto-mobile industry have triggered a significant research interest in the field of vehicular ad-hoc networks (VANETs) over the past few years. A vehicular network consists of vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications supported by wireless access technologies such as IEEE 802.11p. This innovation in wireless communication has been envisaged to improve road safety and motor traffic efficiency in near future through the development of intelligent transportation system (ITS). Hence, governments, auto-mobile industries and academia are heavily partnering through several ongoing research projects to establish standards for VANETs. The typical set of VANET application areas, such as vehicle collision warning and traffic information dissemination have made VANET an interesting field of mobile wireless communication. This paper provides an overview on current research state, challenges, potentials of VANETs as well as the ways forward to achieving the long awaited ITS