Nazmus S. Nafi

A VANET based Intelligent Road Traffic Signalling System

Road Traffic Information System is a key component of the modern intelligent transportation system. Road signaling systems can be made more efficient if real time information from different road sensors and vehicles can be fed in to a wide area controller to optimize the traffic flow, journey time, as well as safety of road users. The VANET architecture provides an excellent framework to develop an advanced road traffic signaling system. In this paper we present a unique VANET based road traffic signaling system that could significantly improve traffic flow, energy efficiency and safety of road users. The VANET based system has been developed using a distributed architecture by incorporating the distributed networking feature. In this paper we first introduce a new Intelligent Road Traffic Signaling System (IRTSS) system based on the VANET architecture. The paper presents some initial simulation results which are obtained by using an OPNET based simulation model. Simulation results show that the proposed architecture can efficiently serve road traffic using the 802.11p based VANET network.

A survey of smart grid architectures, applications, benefits and standardization

The successful transformation of conventional power grids into Smart Grids (SG) will require robust and scalable communication network infrastructure. The SGs will facilitate bidirectional electricity flow, advanced load management, a self-healing protection mechanism and advanced monitoring capabilities to make the power system more energy efficient and reliable. In this paper SG communication network architectures, standardization efforts and details of potential SG applications are identified. The future deployment of real-time or near-real-time SG applications is dependent on the introduction of a SG compatible communication system that includes a communication protocol for cross-domain traffic flows within the SG. This paper identifies the challenges within the cross-functional domains of the power and communication systems that current research aims to overcome. The status of SG related machine to machine communication system design is described and recommendations are provided for diverse new and innovative traffic features.

A predictive road traffic management system based on vehicular ad-hoc network

With an increasing number of vehicles on the road, demand for intelligent transportation systems is on the rise. In this paper, we present a predictive road traffic management system (PRTMS) based on the Vehicular Ad-hoc Network (VANET) architecture. The proposed PRTMS uses a novel communications scheme to estimate the future traffic intensities at different intersections based on a modified linear prediction algorithm. Based on the prediction, a central controller reduces the congestion level by re-routing the vehicles and adaptively changing the signaling cycles. An IEEE 802.11p based vehicle to-infrastructure communications system is used to collect trip information and transmit control signals to enforce multi-junction traffic flow control. Simulations are conducted using an integrated OPNET model comprised of road infrastructure, vehicular mobility management and communications networking to jointly examine the performances of the proposed PRTMS and the VANET. The results indicate that the proposed scheme provides a significant performance improvement in terms of total journey time and waiting time of the vehicles. In addition, the performance of the prediction algorithm is also investigated.

Software defined neighborhood area network for smart grid applications

Abstract Information gathered from the Smart Grid (SG) devices located in end user premises provides a valuable resource that can be used to modify the behavior of SG applications. Decentralized and distributed deployment of neighborhood area network (NAN) devices makes it a challenge to manage SG efficiently. The NAN communication network architecture should be designed to aggregate and disseminate information among different SG domains. In this paper, we present a communication framework for NAN based on wireless sensor networks using the software defined networking paradigm. The data plane devices, such as smart meters, intelligent electronic devices, sensors, and switches are controlled via an optimized controller hierarchy deployed using a separate control plane. An analytical model is developed to determine the number of switches and controllers required for the NAN and the results of several test scenarios are presented. A Castalia based simulation model was used to analyze the performance of modified NAN performance.

Enhanced Distributed Dynamic Skyline Query for Wireless Sensor Networks

Dynamic skyline query is one of the most popular and significant variants of skyline query in the field of multi-criteria decision-making. However, designing a distributed dynamic skyline query possesses greater challenge, especially for the distributed data centric storage within wireless sensor networks (WSNs). In this paper, a novel Enhanced Distributed Dynamic Skyline (EDDS) approach is proposed and implemented in Disk Based Data Centric Storage (DBDCS) architecture. DBDCS is an adaptation of magnetic disk storage platter consisting tracks and sectors. In DBDCS, the disc track and sector analogy is used to map data locations. A distance based indexing method is used for storing and querying multi-dimensional similar data. EDDS applies a threshold based hierarchical approach, which uses temporal correlation among sectors and sector segments to calculate a dynamic skyline. The efficiency and effectiveness of EDDS has been evaluated in terms of latency, energy consumption and accuracy through a simulation model developed in Castalia.

A novel Zigbee based pilot protection scheme for smart distribution grid

Protective relays have become a vital component in power grids due to their multi functionality and crucial role in protecting the distribution network. Usually, a two terminal line could use a pair of protective relays to deliver a fast response when a fault is detected. In this paper an IEEE 802.15.4 Zigbee based wide area smart grid communication network has been developed and a proposed Demand Based Priority Queuing technique is used to provide reliable and high speed delivery of the pilot protection signals. A test bed model was developed to test the communication model feasibility. For high speed machine to machine communication between protection relays, the IEC 61850-90-5 based Generic Object Oriented Event (GOOSE) protocol has been considered. Simulation was carried out utilising Castalia and test bed experiments were conducted using a network of CC2530 chips (Zigbee protocol stack). The results demonstrate that the proposed communication model can operate within guaranteed delay bounds for the pilot signals.

Traffic flow model for vehicular network

Intelligent Traffic Management (ITM) system promises to reduce the traffic congestion, intelligent intersection management as well as the smart dissemination of the informatics to control the traffic flow. Development of any Intelligent Transportation System (ITS) applications requires realistic road traffic model to analysis the performance. Service rate or service time is one of the most important components of any vehicular traffic model to analyze its properties. Traffic flow model which is based on any existing queuing methods have different properties to analyze such delay, queuing length, saturation flow (for fixed cycle of signaling period) etc. Depending on the on road traffic capacity and the intensity of the vehicle the service rate will determine and also the mentioned properties. In this paper, the model involves the analysis of the traffic parameters of an intersection with MM1 queuing system to optimize the service rate that is needed to develop the long term evaluation (LTE) based intersection management system (IMS).

Inter-cluster synchronization scheme for femtocell network

Femtocell is for indoor coverage, and cannot use a GPS antenna for time synchronization. High-precision crystal oscillators can solve the timing problem, but they are often too expensive for consumer grade devices. Since fBS and macrocell Base Station (mBS) network operate on the same frequency under a licensed spectrum fBS network can interfere with the macrocell network. In addition, fBSs can also interfere with each other if multiple units are in close proximity. In some cases, conflicting base stations may simultaneously raise transmit power in order to improve signal quality, thereby creating some interference. Furthermore, in a flat fBS structured network using IEEE 1588 synchronization algorithm and fBS-fBS synchronization scheme creates offset and frequency error which results inaccurate synchronization. However, in this paper an inter-cluster synchronization scheme is proposed in order to reduce offset and frequency error (skew) to achieve precise synchronization in fBS neighbor nodes. The analytical result shows that the proposed scheme is able to reduce the offset and skew significantly through inter-cluster synchronization ultimately increases synchronization accuracy. Therefore, achieved synchronization accuracy is 90% higher than the existing MS-assisted schemes.

A novel software defined wireless sensor network based grid to vehicle load management system

This paper proposes a novel software defined wireless sensor network (SDWSN) based grid to vehicle (G2V) load management scheme to initiate off peak hour valley filling of the daily power supply curve. In particular, this paper focuses on domestic Plug-in Electric Vehicles (PEVs) charging that adopts smart energy allocation technique to maximize the number of charging vehicles and uses a Software Defined Network (SDN) to enable adaptive energy supply. A novel energy scheduling algorithm is proposed based on a linear prediction algorithm that suits the network model built upon a SDN paradigm. To demonstrate the proof of concept, an SDN based Smart Grid Neighborhood Area network (SGNAN) operating onto Wireless Sensor Network (WSN) is developed using Castalia. Simulation results show that the proposed SDWSN network architecture can efficiently support the G2V load management scheme and enables smart valley filling of the daily load curve for maximum utilization of power generation capacity.

A novel vehicle to grid load management scheme based on WiMAX-WLAN in smart grids

Challenges associated with Vehicle to Grid (V2G) power transmission in Smart Grids include dealing with a large number of Plug-in Electric Vehicles (PEVs) and establishment of a robust and reliable communication network for short burst transmissions. This paper proposes an end-to-end load management scheme to enable V2G power transmission based on a WiMAX WLAN hybrid network architecture in Smart Grids and considers the case of peak power via discharging PEVs with small energy bursts while WiMAX-WLAN network efficiently deals with flexible data aggregation to reduce signaling and protocol overheads. A novel energy scheduling algorithm is presented for an efficient admission control process and to deal with variable energy budgeting within a specific timeframe. A wide area heterogeneous network based on WiMAX and WLAN was modelled to examine the performance of the energy scheduling algorithm and the communications network for large-scale V2G power management. Results presented show that the proposed scheme can successfully manage the V2G power supply with a very low signaling overhead.