Syed Masud Mahmud

A novel algorithm to form stable clusters in vehicular ad hoc networks on highways

Clustering in vehicular ad hoc networks (VANET) is one of the control schemes used to make VANET global topology less dynamic. Many of the VANET clustering algorithms are derived from mobile ad hoc networks (MANET). However, VANET nodes are characterized by their high mobility, and the existence of VANET nodes in the same geographic proximity does not mean that they exhibit the same mobility patterns. Therefore, VANET clustering schemes should take into consideration the degree of the speed difference among neighboring nodes to produce relatively stable clustering structure. In this paper, we introduce a new clustering technique suitable for the VANET environment on highways with the aim of enhancing the stability of the network topology. This technique takes the speed difference as a parameter to create relatively stable cluster structure. We also developed a new multi-metric algorithm for cluster-head elections. A simulation was conducted to evaluate our method and compare it with the most commonly used clustering methods. The simulation results show that our technique provides more stable cluster structure on the locale scale which results in a more stable network structure on the global scale. The proposed technique reduces the average number of clusters changed per vehicle by 34-46%, and increases the average cluster lifetime by 20-48% compared to the existing techniques.

An intelligent light control system for power saving

Saving energy has become one of the most challenging issues these days. The most waste of energy comes from the inefficient use of the electrical energy consumed by artificial light devices (lamps or light bulbs). This paper presents a system with detailed design for saving electrical energy by controlling the intensity of artificial light to a satisfactory level and getting use of the day light when possible with the best effort for energy saving. An improvement to daylight harvesting and controlled dimming systems is introduced while counting for over illumination cases. The idea behind is to control the venetian blinds or curtains in such a way to make use of the daylight if it is available. Otherwise, it uses the artificial internal building light. Controlling the amount of daylight passing inside is via controlling the opening angle of the venetian blinds while controlling the intensity of artificial light is by controlling the amount of power delivered to the lamp via Pulse Width Modulation (PWM) for DC lamps or clipping the AC wave for AC light bulbs. The system uses Controller Area Network (CAN) as the media of communication with the sensors and the actuators. The system is modular and can be expanded to span large buildings. The advantage of the design is that it gives the user a single point of operation which is the amount of desired light. The controller is responsible to determine a way to satisfy the amount of light desired with the least energy consumption. One of the major issues considered is the ease of installation and the low cost of the system components. The system shows a significant amount of energy saved and feasibility in practical implementation.

High precision phase measurement using adaptive sampling

The conventional phase measurement techniques introduce error in the phase when the input signals are distorted by harmonics. A novel technique, known as adaptive sampling, for high-precision phase measurement is introduced. A digital signal-processing approach is used in this technique. The maximum sampling rate required for this technique is h+2 samples/cycle of the input signals, i.e. (h+2)f sampless, where h, is the highest harmonic present in the signals and f is the fundamental frequency of the signals. This sampling rate is way below the Nyquist sampling rate (more than 2hf samples/s) when h is a large number. In the adaptive sampling technique the sampling rate is started from three samples/cycle and then is gradually increased until the phase is correctly measured. This phase measurement technique has been verified using synthesized signals. >

Analysis of attacks against the security of keyless-entry systems for vehicles and suggestions for improved designs

Remote control of vehicle functions using a handheld electronic device became a popular feature for vehicles. Such functions include, but are not limited to, locking, unlocking, remote start, window closures, and activation of an alarm. As consumers enjoy the remote access and become more comfortable with the remote functions, original equipment manufacturers (OEMs) have started looking for new features to simplify and reduce the user interface for vehicle access. These new features will provide users with an additional level of comfort without requiring them to touch or press any button on any remote devices to gain access to the vehicle. While this extra level of comfort is a desirable feature, it introduces several security threats against the vehicles keyless-entry system. This paper describes a number of attacks against the security of keyless-entry systems of vehicles and also presents analyzes of several attacks and compares the vulnerability of the system under different attacks. At the end, some suggestions for improved design are proposed.

Media Access Technique for Cluster-Based Vehicular Ad Hoc Networks

We propose a hybrid media access technique for cluster-based vehicular networks. This technique integrates the centralization approach of cluster management and the universal way of forwarding data, where the farthest vehicle forwards data in an effort to maximize the opportunity of advanced notification. This method leverages contention-free and contention-based MAC, to support the different requirements of safety and non-safety messages. Inter-cluster interference avoidance is also supported. The analysis and simulation show that using this scheme, for inter-cluster communications, provides an early notification compared to other existing clustering methods.

Secure software upload in an intelligent vehicle via wireless communication links

The demand for drive-by-wire, telematics, entertainment, multimedia, pre-crash warning, highway guidance, remote diagnostic, etc. will significantly increase the complexity of a vehicles software modules. From time to time, the vehicles software may need to be updated due to many reasons such as the introduction of new features in vehicles, changing the navigation map, fixing software bugs, etc. Software updates must be done in secure modes to avoid any future disasters due to malfunctions of the vehicle. In this paper, we propose an architecture for secure software uploads in vehicles. We provide a detailed description of the secure software upload process.

Error analysis of digital phase measurement of distorted waves

An analysis of errors associated with the digital measurement of phase angle between two signals, one of which may be distorted by a harmonic, is presented. All the results were found by running a simulation program on a VAX 11/780 computer. The results are very useful for the users of the phase meters. This technique may introduce large errors for some particular types of input waves. The main purpose of this work is to explain how large the error could be under certain conditions on the input waves. >

In-vehicle secure wireless personal area network (SWPAN)

During the last several years, the interest in wireless networking has grown significantly due to the availability of many wireless products, such as cell phones, wireless enabled mice, keyboards, modems, and many other products. Bluetooth-enabled cell phones, personal digital assistance (PDAs), and laptops are becoming common. Wireless fidelity (Wi-Fi) products are growing at a rapid rate. Several companies have already started developing WiMax products. The reason for the rapid growth of wireless technology is that it provides the users with additional convenience over the wired technology. General Motors Corporation introduced a Bluetooth network in its 2003 Saab 9-3 model car. Having a wireless personal area network (WPAN) in a vehicle will allow the driver to control the various operations within the vehicle without taking his hands off the steering wheel. For example, the driver will be able to make a phone call through a Bluetooth-enabled headset and a Bluetooth-enabled cell phone using voice-activated dialing features. If the Bluetooth network is connected to the vehicles wired network through an appropriate gateway device, then the driver will be able to control the lights, windshield wipers, air flow, heat, and various other features of the vehicle through a Bluetooth-enabled headset and voice-activated features. An in-vehicle WPAN will also allow the users to use their PDAs as electronic car keys. Though an in-vehicle WPAN can provide the users with many convenient features, it can also make the vehicle system vulnerable to many types of security attacks unless it is properly designed. In this paper, the authors present a technique for building an in-vehicle secure WPAN (SWPAN). The technique is user friendly and easy to use

Some attacks against vehicles' passive entry security systems and their solutions

Recently, several companies have introduced passive entry systems for automotive applications. These systems are intended to increase user comfort by eliminating the requirement that the user has to reach for the customer identification device (CID), a credit card like tool, to gain access to the vehicle compartment. While this extra level of comfort is a desirable feature, especially in luxury vehicles, it introduces several key attacks against the system. This paper describes several techniques of potential attacks against the passive entry system and proposes solutions to protect the vehicle from such attacks.

In-Vehicle Network Architecture for the Next-Generation Vehicles

The demand for drive-by-wire, telematics, entertainment, multimedia, pre-crash warning, remote diagnostic and software update, etc. will significantly increase the complexity of the future in-vehicle communication networks. New types of communication networks will also be necessary to satisfy the requirements of safety and fuel efficiency, and meet the demand for new features. Different sets of vehicle electronic modules will require different types of networks. For example, drive-by-wire and active collision avoidance systems need fault tolerant networks with time-triggered protocols, to guarantee deterministic latencies; multimedia systems need networks with high bandwidth to transfer video files; and body control electronics need low-bandwidth networks to keep the cost down. As the size and complexity of these networks increase, ease of integration has become a major challenge for design engineers. In todays vehicles, there are mainly two networks: a high-speed network for the power train and a low-speed network for the body electronics. Since the complexity of the network is increasing and the demand for bandwidth is growing, future vehicles will require many partitioned networks. The partitioning of the networks will be done based on the locality as well as the functionality of the modules. One of the challenging issues will be the selection of topology to interconnect various in-vehicle partitions of the network. Interconnection among all in-vehicle partitions of the network is necessary for diagnostics and software updates in various modules. One logical approach for interconnecting various partitions of the network would be via a hierarchical bus. This paper shows various types of hierarchical connections among the partitions of in-vehicle networks. Different partitions may use different protocols. For example, one partition may use the CAN protocol, the second partition may use the TTCAN protocol, the third partition may use the LIN protocol, and so on. The hierarchical bus will be using intelligent switches to facilitate the translation of messages from one protocol to another protocol while the messages will be moving from one partition to another partition. This paper discusses the advantages and disadvantages of various types of hierarchical connections in terms of cost, bandwidth, latency, fault tolerance, and many other features. The paper also presents simulation models that can be used to determine the performance of various types of partitions and network topologies.