Bamidele Adebisi

High-speed narrowband PLC in Smart Grid landscape — State-of-the-art

The prospect of Smart Grid (SG) is becoming a reality in the recent years, covering different areas like smart metering, demand side management, or distributed generation. Communications play a central role in the SG architecture, because the power utilities need to collect important information to make optimal decisions for efficient power generation, transmission and distribution. This paper discusses the state-of-the-art of narrow-band high-speed power line communications (PLC) - a promising communication platform for SG which offers advantages in coverage, costs and availability. Further, the paper presents an overview of DLC+VIT4IP (Distribution Line Carrier: Verification, Integration and Test of PLC Technologies and IP Communication for Utilities) a EU funded project under the 7th Framework Programme (FP7) that aims to extend the existing PLC technologies by developing efficient transport of IPv6 protocol, automatic measurement, configuration and management, and security. In addition, the project is exploiting frequency ranges up to 500 kHz, to support systems serving larger smart grid applications.

IP-centric high rate narrowband PLC for smart grid applications

The Internet Protocol version 6 is expected to be a strong enabler for the smart grid, promising seamless communication and network technology independence. However, IP has to be delivered to the last node in the field in order to become the lingua franca of the future smart grid. This article presents a novel approach in power line communication that delivers high resilient communication capable of efficiently transmitting IPv6. Based on the requirements of smart grid applications, the architecture of the communication system developed in the DLC+VIT4IP project is presented. New techniques for integrating IPv6, IPsec security, robust header compression, and end-to-end QoS are described, demonstrating the capability of PLC to efficiently handle IPv6 in the field level of the smart grid.

Dynamic clustering and management of mobile wireless sensor networks

In Wireless Sensor Networks (WSNs), routing data towards the sink leads to unbalanced energy consumption among intermediate nodes resulting in high data loss rate. The use of multiple Mobile Data Collectors (MDCs) has been proposed in the literature to mitigate such problems. MDCs help to achieve uniform energy-consumption across the network, fill coverage gaps, and reduce end-to-end communication delays, amongst others. However, mechanisms to support MDCs such as location advertisement and route maintenance introduce significant overhead in terms of energy consumption and packet delays. In this paper, we propose a self-organizing and adaptive Dynamic Clustering (DCMDC) solution to maintain MDC-relay networks. This solution is based on dividing the network into well-delimited clusters called Service Zones (SZs). Localizing mobility management traffic to a SZ reduces signaling overhead, route setup delay and bandwidth utilization. Network clustering also helps to achieve scalability and load balancing. Smaller network clusters make buffer overflows and energy depletion less of a problem. These performance gains are expected to support achieving higher information completeness and availability as well as maximizing the network lifetime. Moreover, maintaining continuous connectivity between the MDC and sensor nodes increases information availability and validity. Performance experiments show that DCMDC outperforms its rival in the literature. Besides the improved quality of information, the proposed approach improves the packet delivery ratio by up to 10%, end-to-end delay by up to 15%, energy consumption by up to 53%, energy balancing by up to 51%, and prolongs the network lifetime by up to53%.

A Wireless Sensor Network Border Monitoring System: Deployment Issues and Routing Protocols

External border surveillance is critical to the security of every state and the challenges it poses are changing and likely to intensify. Wireless sensor networks (WSN) are a low cost technology that provide an intelligence-led solution to effective continuous monitoring of large, busy, and complex landscapes. The linear network topology resulting from the structure of the monitored area raises challenges that have not been adequately addressed in the literature to date. In this paper, we identify an appropriate metric to measure the quality of WSN border crossing detection. Furthermore, we propose a method to calculate the required number of sensor nodes to deploy in order to achieve a specified level of coverage according to the chosen metric in a given belt region, while maintaining radio connectivity within the network. Then, we contribute a novel cross layer routing protocol, called levels division graph (LDG), designed specifically to address the communication needs and link reliability for topologically linear WSN applications. The performance of the proposed protocol is extensively evaluated in simulations using realistic conditions and parameters. LDG simulation results show significant performance gains when compared with its best rival in the literature, dynamic source routing (DSR). Compared with DSR, LDG improves the average end-to-end delays by up to 95%, packet delivery ratio by up to 20%, and throughput by up to 60%, while maintaining comparable performance in terms of normalized routing load and energy consumption.

Space-Frequency and Space-Time-Frequency M3FSK for Indoor Multiwire Communications

This paper investigates the multiple emitting multiple receiving points diversity technique as one of the ways of meeting the tripartite conditions of high data rate, less transmit power, and low unwanted electromagnetic radiations of the frequency-selective power-line channels. To be resilient to the intersymbol interference present in frequency-selective fading, the diversity technique must be used in conjunction with wideband multicarrier modulation. We propose an efficient space-frequency and space-time-frequency (STF)-coded multitone M-ary multilevel frequency-shift keying (M3FSK) for high-rate indoor communications over the multiwire power-line channels. We show that coding by using three dimensions of space, frequency, and time, the STF system is capable of achieving up to 8-dB diversity gain. Simulation results are provided to demonstrate the performance improvement of the STF over other diversity schemes as well as over single-wire M3FSK systems in a highly impulsive power line.

Comparisons of Indoor PLC Emissions Measurement Results and Regulation Standards

Measurements of emissions are carried out over a low voltage (LV) indoor power line system in the frequency range of 1 MHz - 30 MHz. In the measurement setups, efforts are made to comply with the setup specified in the existing standards. The results obtained are compared to the current regulations/proposed limits. It is shown that the measured emissions do not currently meet all the specified limits. It is also suggested that future power line communications systems will have to transmit at lower radiation power levels in order to meet those limits

Channel characterisation of cooperative relaying power line communication systems

Power line communication (PLC) technology offers a promising platform for numerous communication applications. The power lines however can significantly attenuate communication signals operating in high frequency band. For this reason, multi-hop PLC systems become desirable. In this paper, we investigates the effect of multi-hop relaying on the power line channel transfer function. Measured results are compared with results obtained from sumulations in Matlab. Results show that the presence of relays between a transmitting and a receiving PLC nodes can intensify the attenuation and frequency selectivity. Measurements show that maximum attenuation increases with number of relays.

Location prediction optimisation in WSNs using Kriging interpolation

Many wireless sensor network (WSN) applications rely on precise location or distance information. Despite the potentials of WSNs, efficient location prediction is one of the subsisting challenges. This study presents novel prediction algorithms based on a Kriging interpolation technique. Given that each sensor is aware of its location only, the aims of this work are to accurately predict the temperature at uncovered areas and estimate positions of heat sources. By taking few measurements within the field of interest and by using Kriging interpolation to iteratively enhance predictions of temperature and location of heat sources in uncovered regions, the degree of accuracy is significantly improved. Following a range of independent Monte Carlo runs in different experiments, it is shown through a comparative analysis that the proposed algorithm delivers approximately 98% prediction accuracy.

Performance evaluation of MAC backoff algorithm in Narrowband PLC

This paper investigates the backoff algorithm for Narrowband Power Line Communications (PLC) Medium Access Control (MAC) protocol. Specifically, the paper considered the MAC designed by Yitran and implemented within its Differential Code Shift Keying (DCSK) technology. In this algorithm width of the contention window is calculated based on the estimated number of active nodes in the network. Further the performance of the algorithms were evaluated under different saturated throughput conditions and varying number of active nodes, in a fully meshed network. Comparison were also made between the simulated and the polynomial backoff algorithms dynamic characteristics. Simulation results show that the algorithm under investigation has an excellent performance under the saturated throughput, although its dynamic characteristic can be further improved.

Wire integrity testing using intermodulation product processing

This paper investigates wire integrity testing using intermodulation product processing. In many practical scenarios, especially in wireless systems, intermodulation products are considered inimical to effective communications. However, this paper demonstrates that the location of faults on electrical wires can be discovered by detecting and processing the intermodulation products that arise when faulty wires are excited at different frequencies. Furthermore, by characterising these faults; it is possible to determine whether they are progressively getting worse. This makes the use of the system as a feasible diagnostic tool, in which case, ageing wiring is detected and replaced before it becomes a safety hazard This method can be used for fault detection on overland electrical transmission lines, nuclear power plants, ships, in-house wiring, Digital Subscriber Line (DSL) and onboard aircraft. The system when fully developed is expected to use the powerline communication (PLC)