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About this book

This book constitutes the proceedings of the Third International Conference on Smart Grid and Innovative Frontiers in Telecommunications, SmartGIFT, held in Auckland, New Zealand, in April 2018. The 28 revised full papers presented were carefully reviewed and selected from 44 submissions. They focus on smart grid as the next generation of electrical grid, which will enable the smart integration of conventional, renewable and distributed power generation, energy storage, transmission and distribution, and demand management. The benefits of smart grid include enhanced reliability and resilience, higher intelligence and optimized control, decentralized operation, higher operational efficiency, more efficient demand management, and better power quality.

Table of Contents


Temporary Internet Access for Authentication and Key Agreement for LTE Networks

Evolved Packet System-Authentication and Key Agreement (EPS-AKA) is the security protocol in Long-Term Evolution (LTE). However, it is still vulnerable to user identity attacks and fake eNBs. Efficient EPS-AKA (EEPS-AKA) was proposed with some improvements. Nevertheless, the EEPS-AKA is vulnerable to denial-of-service (DoS) attacks and fake eNBs, despite of some minor flaws in its procedures. In this paper, we propose Temporary Internet Access (TIA)-AKA to: (1) prevent user identity disclosure by implementing some additional steps, which allows a user equipment (UE) to request a temporary UE identity to access Internet; and (2) authenticate the Mobility Management Entity (MME) through the validity of the assigned IP address. Physical address and simple password exponential key exchange (SPEKE) method are combined into the proposed TIA-AKA. Efficiency analysis suggests the TIA-AKA provides a fully protection on the user identity and prevent the DoS attack, at the expense of increased bandwidth consumption and processing delay.
Xue Jun Li, Maode Ma, Jiecheng Xie

A Smartphone-Assisted Device-to-Device Communication for Post-disaster Recovery

Natural disasters like earthquakes often cause partial or complete breakdown of existing telecommunication infrastructure leaving the helpless people in the affected areas without means of exchanging emergency messages. Under such situations, a temporary ad-hoc system to help in exchanging emergency communication messages and post-disaster recovery can be set up utilising the smartphones of affected victims and the IoT devices of the smarthomes in the affected areas and this paper proposes a method to do that. In the proposed method, smarthome IoT devices are set up to act as relay nodes to communicate emergency messages in absence of a fully functioning telecommunication network. A relay node is chosen based on multiple independent parameters like the residual lifetime of an IoT device and its degree of connectivity. MATLAB-based simulations conducted prove the efficiency of the method.
Md. Akbar Hossain, Sayan Kumar Ray

Heuristics-Based Detection of Abnormal Energy Consumption

This paper presents two methods for detecting abnormal electricity consumption by utilizing usage patterns in the vicinity. The methods use contextual and factual information including, energy consumption patterns, nature of supply and category of day to logically group meters and find abnormalities. Using heuristics proposed in the paper, data collected from fifty smart meters deployed inside hostels of IIIT-Delhi were investigated for abnormal electricity consumption. Multiple abnormalities were found and their causes were verified after discussion with campus administrators. Our results show that the proposed heuristics successfully found abnormal energy consumption behavior. Therefore, these methods could be used for real-time abnormality detection. This will result in reducing operating costs by automatically detecting and reporting abnormalities without human intervention.
Ankur Sial, Amarjeet Singh, Aniket Mahanti, Mingwei Gong

Real-Time CPU Scheduling Approach for Mobile Edge Computing System

Mobile edge computing (MEC) system has outstanding advantages of providing smart city applications with relatively low latency and immediately response. How to guarantee the QoS of the services in MEC system is consequently becoming a hot issue. This work focuses on solving the problem by real-time CPU scheduling. The proposed scheduling algorithm considers different services arrival profiles, computation time consumption and deadline requirements simultaneously. Specifically, the combination and optimization of support vector machine (SVM) and earliest deadline first (EDF) algorithm is designed, which could automatically classify services type and efficiently allocate the computation time in real-time manner. By deploying the traffic trace from the real world, the proposed scheduling algorithm could reduce \(45\mathrm{{\% }}\) latency and improve the reliability of transmission, comparing with popular fixed-priority CPU scheduling algorithm.
Xiaoyi Yu, Ke Wang, Wenliang Lin, Zhongliang Deng

Optimal Placement and Sizing of DG and Shunt Capacitor for Power Loss Minimization in an Islanded Distribution System

Active power loss of transmission lines in a distribution system has been a frequent concern for a great number of researchers. Various approaches have been proposed to minimize active power loss. In this research, two approaches, optimal placement and sizing of distributed generation (DG) and shunt capacitor, are used to reduce the active power loss in a distribution system. Particle Swarm Optimization (PSO) and Newton-Raphson method are integrated to find the optimal location and size of DG and shunt capacitor while maintaining operation constraints. The proposed technique is tested on a radial distribution system based on Vava’u island’s distribution system in Tonga. The algorithm is implemented in MATLAB and the results are verified with DIgSILENT PowerFactory. Three case scenarios of the optimal placement and sizing, namely: DG only, shunt capacitor only, and DG & shunt capacitor, were tested. The technique successfully found the optimal location and size of DG and shunt capacitor in three case scenarios and further found the most optimal solution among these three cases.
Mingu Kang, Ramon Zamora

Applications of Temporal Network Coding in V2X Communications

Due to network dynamics and channel fading, multi-hop communication in vehicular networks usually suffers from much higher packet loss rate than the conventional static or single-hop networks. By encoding over packets received at different time slots at the intermediate nodes, temporal network coding (TNC) is a promising technique to avoid erasure accumulation with communication hops. In this paper, we present different strategies of TNC schemes to meet the decoding and delay requirements of different V2X (vehicle to everything) applications. Specifically, for applications with stringent delay requirement, such as live video streaming, we propose to use chunked TNC without precoding. For multi-hop communications with high throughput requirement, we propose to apply carefully designed precoding on top of the TNC to enhance the end-to-end throughput. Different from the conventional TNC code designs, we apply TNC design with overhearing, exploiting the broadcast nature of wireless communication. Specifically, we assume that a vehicle can not only receive the packets from its immediate upstream vehicle, but also overhear some packets from further-upstream vehicles. The number of network coded packets generated at the intermediate nodes is designed by considering the packets received via both the upstream and overheard transmission, which helps to maximize the communication throughput delivered to the destination node.
Xiaoli Xu, Yumeng Gao, Yong Liang Guan

Blockchain Based Energy Trading Model for Electric Vehicle Charging Schemes

The electricity market is undergoing a transformation with increasing number of electric vehicles (EV). This paper studies the current charging and discharging schemes for EV and the feasibility of the decentralized transactional energy market. In order to adapt the high volume of EV integration and fully decentralize the grid system, the blockchain technology is introduced to serve as an envision for the next generation grid. Furthermore, we propose a blockchain technology enabled electricity exchange market to enable EVs’ autonomy in trading energy with secured distributed energy transactions. The constructed exchange market is price competitive platform where the best bid price is modelled via the jump-diffusion process to enable users to participate in the trading process. We demonstrate that our proposed distributed energy exchange system can perform the peer-to-peer transaction with the real-time electricity price aligning with the EV power demand trend without requiring a third-party intermediary.
Chao Liu, Kok Keong Chai, Eng Tseng Lau, Yue Chen

Energy-Efficiency Maximisation in Random Cognitive Radio Networks

Energy-efficient cognitive radio network has received considerable attention recently because of improving spectrum and energy efficiency. In light of such observations, we present a model for cognitive radio network based on stochastic geometry theory where transmitters and receivers are distributed according to Poisson point process. In this paper, we focus on the optimization problem where energy efficiency is maximized under the constraint of outage probability for primary network and secondary network. We show that the energy efficiency is increased with the increment of threshold for primary network. However, the energy efficiency is maximum for a certain value of threshold in secondary network.
Saifur Rahman Sabuj, Md Akbar Hossain, Edmund Lai

Opportunistic Fog Computing for 5G Radio Access Networks: A Position Paper

Fog-based radio access networks (F-RAN) are posed to play a pivotal role in the much-anticipated 5th Generation (5G) cellular networks. The philosophy of F-RAN is to harness the distributed resources of collaborative edge devices to deliver localized RAN services to the end users. The current F-RAN is implemented mainly utilizing dedicated hardware and do not leverage on the available large number of distributed edge devices. This paper introduces the idea of opportunistic fog RAN (OF-RAN) which comprises of virtual fog access points (v-FAPs). The v-FAPs are formed opportunistically by one or more local edge devices also referred to as service nodes, such as WiFi access points, femtocell base stations and more resource rich end user devices under the coverage and management of the physical FAP, which can be dedicated fog server, fog-enabled remote radio heads (RRHs) or macrocell base stations. The proposed OF-RAN can be a low latency and high scalable solution for 5G cellular networks.
Jofina Jijin, Boon-Chong Seet

A Sustainable Connectivity Model of the Internet Access Technologies in Rural and Low-Income Areas

The Internet has evolved as a critical booster for the economic, social and technical development of human society. Almost half of the world’s population is unfortunately missing out due to the lack of access to the Internet. Such users are mainly those living in rural and low-income areas. Various strategies and approaches for improving the Internet’s accessibility are available, each with a different set of benefits, costs, and risks. It is important to choose solutions from these feasible options that promise to promote the efficiency as well as the sustainability of the ‘Internet Ecosystem’. In this paper, we propose a new model of sustainable connectivity that integrates three factors (affordability, social shareability, and geographical network coverage) that must be considered in the selection and design of Internet access solutions. In addition, we develop a hypergraph-based network graph solution that illustrates the relationship among the three factors. Then, we use Coloured Petri Nets (CPNs) to model and simulate the possible Internet access solutions and also interplay those three factors to study how they impact the overall network connectivity performance. Our initial results have revealed how sustainable Internet connectivity behaves as a function of the affordability, social interaction, and geographical network coverage and investigates how these factors could be leveraged to provide different network connectivity and Internet access solutions.
Maria Elena Villapol, William Liu, Jairo Gutierrez, Junaid Qadir, Steven Gordon, Jin Tan, Luca Chiaraviglio, Jinsong Wu, Wenjun Zhang

E-Mobility: Smart Grid and Charging Session of Electric Vehicles

This research stresses upon the importance of electric mobility in modern age as sales of Electric Vehicles (EV) have crossed one million cars and current number of charging stations are rapidly growing. In this context, we propose a novel smart connection called DriWe between the EV, the charging point and the environment to improve and consolidate the development of smart grids vs the charging enhancement. In DriWe, performance of the monophasic environment is optimized, providing support to the owner of the EV in order to (i) always achieve maximum power, (ii) easily reach the charging facilities through a special application that can be installed in tablet, smartphone or pc, and identify the various charge points (iii) guarantee the absence of electric blackout, thanks to a combination and an interaction of three elements: smart device, an intelligent framework, namely a DriWe cloud server and charge point. A dynamic load control method based on an Application Programming Interface (API) with a 10 s frame rate update, is applied. The program runs within the end-user smart phone, acquires data from DriWe cloud server, and allows to coordinate the recharge column by allowing the Electric Vehicle (EV) supply equipment’s control and variation.
Gabriele Corzato, Luca Secco, Arslan Rasheed, Atulya Kumar Nagar, Emanuele Lindo Secco

Optimizing Sliding Performance in iOS

How to improve iOS sliding performance has always been the focus of iOS application optimization. This paper analyzes the principle of AutoLayout and Frame view layout, the opportunity of network loading, CPU and GPU performance consumption during sliding process. First, we provide the appropriate solution to avoid using AutoLayout, and adjust the time of network loading by preloading to reduce the waiting time dynamically. Pre-cache and asynchronous rendering to reduce the main thread CPU consumption is implemented to reduce the main thread CPU consumption, and at the same time, GPU consumption is reduced by asynchronous rendering. Finally, verify the feasibility and effectiveness of the optimization scheme by experiments. It is verified that the percentage of the main thread CPU consumption decreases by 17.2% and FPS increases from 37 Hz to 60 Hz.
Qin Zhao, Qi Qi, Lejian Zhang, Qiwei Shen

A Dialog Robot Based on WeChat

WeChat is one of the most popular instant messaging applications in the world. It has now become an important access to variety business systems for billions of users. The vast majority of companies want to provide their business services onto WeChat in order to gain advantage in fierce market competitions. However, as far as we know, today it is not easy to access WeChat with business service. In this paper, we propose a framework to integrate business services and WeChat. On the basis of this framework, companies or entrepreneurs can provide their business services on WeChat easily. Finally, we use a case study to demonstrate how our service can be used in helping tickets sells and statistical analysis.
Xiaoyi Chen, Jing Wang, Qiwei Shen, Qi Qi, Jingyu Wang

NO-V2X: Non-orthogonal Multiple Access with Side Information for V2X Communications

We study a vehicle-to-everything (V2X) communication scenario where multiple vehicles coming from different road segments converge at a road junction and exchange their information via a road side unit. The high-mobility of vehicles determines that the communication is time-critical. If conventional orthogonal multiple access (OMA) is applied, not only the orthogonal resource allocation but also the scheduling overheads will incur significant delay. In addition, orthogonal domain may not be identified within short contact time among vehicles and the road-side unit. In contrast, non-orthogonal multiple access (NOMA) can provide low-delay and reliable communication by exploiting the overlapped or collided signals. In this paper, we investigate the application of NOMA with side information in V2X communications as the Non-orthogonal V2X (NO-V2X) scheme. NO-V2X takes the advantage of side information and physical-layer network coding (PNC) to increase the decoding success rate in the uplink phase and to reduce the required transmission power in the downlink phase. Our simulation results show that NO-V2X outperforms OMA and the conventional NOMA with successive interference cancellation (SIC).
Zhenhui Situ, Ivan Wang-Hei Ho

Connecting Makaraka - A Case Study to Provide Connectivity in the Rural Area of New Zealand

Broadband availability is an important asset for deriving change in the societal and economic development of a country. New Zealand’s rural areas have limited broadband connectivity and there are some beautiful tourist destinations which do not have broadband availability on site. In this paper, we aim to provide a broadband connectivity model for basic and high speed data services for the area of Makaraka in the Gisborne region of New Zealand. The model proposes the placement of the access points, their channel selection scheme, transmit power requirements and appropriate installation height in detail for different frequency bands and data rate requirements. It is evident from the simulated results that outdoor area of Makaraka is able to get broadband connectivity which will help NZ to drive towards the theme of highly-connected society.
Syeda Kanwal Zaidi, Ali Abdul Adheem, Syed Faraz Hasan, Xiang Gui

A New Energy Efficient Big Data Dissemination Approach Using the Opportunistic D2D Communications

The emerging cyber-physical paradigm endeavours to unite all the physical objects embedded with electronics, software, sensors, and network connectivity to allow more direct interactions and information sharing between the physical and cyber worlds. While these massively connected devices and their associated communications can exponentially increase the data generation, transmission, and processing which consume a huge amount of energy and finally end up with harming the environment seriously. In this paper, we propose a solution for energy efficient data dissemination by using the opportunistic device-to-device (D2D) communications. Each sender can decide either use network infrastructure or through encountering the end-users according to the quality of service (QoS) requirements of each data demand and also the mobility behaviors of the users. These decisions are based on the time and location- traces of daily mobility routines and related activities of users and their social relationship. The case study, based on the similarity analysis of the mobility traces, has confirmed the rich opportunities for encountering among people, thus the proposed approach has great promises to reduce the energy consumption of big data dissemination.
Ambreen Memon, William Liu, Adnan Al-Anbuky

Prediction of Electricity Consumption for Residential Houses in New Zealand

Residential consumer’s demand of electricity is continuously growing, which leads to high greenhouse gas emissions. Detailed analysis of electricity consumption characteristics for residential buildings is needed to improve efficiency, availability and to plan in advance for periods of high electricity demand. In this research work, we have proposed an artificial neural network based model, which predicts the energy consumption of a residential house in Auckland 24 h in advance with more accuracy than the benchmark persistence approach. The effects of five weather variables on energy consumption was analyzed. Further, the model was experimented with three different training algorithms, the levenberg-marquadt (LM), bayesian regularization and scaled conjugate gradient and their effect on prediction accuracy was analyzed.
Aziz Ahmad, Timothy N. Anderson, Saeed Ur Rehman

Physical-Layer Network Coding with High-Order Modulations

Physical-Layer Network Coding (PNC) can double the throughput of a Two-Way Relay Network (TWRN) by reducing packet exchanging timeslots. In a multi-user wireless communication system, time domain phase shift can inevitably lead to deterioration of PNC performance. In previous studies, there have been many studies result to enhance the performance of some low-order modulation techniques such as BPSK and QPSK, but fewer studies are designed for high-order modulation such as 16-QAM. It is known that high-order modulation is the only way to improve the spectrum utilization rate. This paper uses simulation to explain that the time domain phase shift will greatly affect the performance of 16-QAM PNC, and its’ performance couldn’t be improved even polar code is used. To address this phase penalty problem, we propose a half-symbol asynchronous algorithm to introduce correlations using belief propagation (BP). Simulation results show that the time domain phase shift problem of 16-QAM modulated PNC systems can be solved effectively using our proposed half-symbol asynchronous BP algorithm.
Xuesong Wang, Lu Lu

Non-orthogonal Multiple Access for Similar Channel Conditions

Non-orthogonal multiple access (NOMA) is considered as promising multiple access (MA) scheme for upcoming fifth generation (5G) systems. The performance of NOMA is highly dependent upon having significant channel gain difference among users. In this paper, we focus on the situation of similar channel conditions and propose a channel gain stretching (CGS) strategy to apply NOMA more effectively under these conditions. In order to evaluate the performance, we derive a closed-form expression of the outage probability. Numerical results are also presented to validate the accuracy of the derived results and also to compare the performance of NOMA with and without CGS, and orthogonal MA (OMA).
Asim Anwar, Boon-Chong Seet, Xue Jun Li

IoT Based Experimental Study to Modify Water Consumption Behavior of Domestic Users

In this paper, we present the results of a small experimental study to understand and quantify the impact of real time feedback on water consumption behavior inside buildings. We develop a low cost water monitoring node, which can be conveniently installed without plumbing requirements on water fixtures found in typical households and commercial buildings. In our experiment, we installed the developed Internet of Things (IoT) node on a kitchen sink in a commercial building. The sink was used primarily for washing mugs, plates, and making tea & coffee. We collected, analyzed and compared the data of different users for different activities (e.g., washing mugs and plates) to understand their water consumption pattern. Then, we provided real time feedback for three weeks to two major water consumers after every activity about potential water wastage. We observed a significant improvement in the water consumption behavior of these users (water wastage reduction up to 50%). This study clearly demonstrates the utility of low cost IoT based solutions and real time feedback in modifying water consumption behavior of domestic users.
Aneeq-ur Rehman, Reeba Raza, Naveed Ul Hassan, Yuren Zhou, Rui Liu, Benny Kai Kiat Ng, Chau Yuen

A Sustainable Marriage of Telcos and Transp in the Era of Big Data: Are We Ready?

The emerging smart city paradigm e.g., intelligent transport, smart grid and participatory sensing etc. is to advance the quality, performance and experience of urban citizten services through greater connectivity. This paradigm needs to collect data from citizens, various devices and assets that could be monitored, processed and analysed for the city governers to make better decision and also more efficiently manage those assests and resources. While the telecommunication and Internet are progressively being over-burdened and congested by the growing data transmission demands. To keep expanding the telecommunications and Internet infrastructures to accomodate these intensive data demands is costly and also the associated energy consumptions and carbon emissions could at long last wind up genuinely hurting the environment. To face this issue in the coming era of big data, we envision it will be best to utilize the established urban transport and road infrastructure and existing daily massive vehicular trips, to complement traditional option for data transmission. After detailing the current state-of-the-art, we consider the main challenges that need to be faced. Moreover, we define the main pillars to integrate the telecommunications and transport infrastructures, and also a proposal for the future urban network architecture.
Salman Naseer, William Liu, Nurul I. Sarkar, Peter Han Joo Chong, Edmund Lai, Maode Ma, Rangarao Venkatesha Prasad, Tran Cong Danh, Luca Chiaraviglio, Junaid Qadir, Yue Cao, Jinsong Wu, Raymond Lutui, Shahid Manzoor

Review of Cost Optimization of Electricity Supply by Using HOMER and a Case Study for a Big Commercial Customer in Brazilian Amazon Area

Renewable energy utilization for electricity supply has increased significantly. Technology maturity, cost reduction, and environmental friendliness are significant factors that encourage this increase. The expansion of distributed generation is increasing significantly due to the concern of many householders and entrepreneurs in minimizing the energy costs at residential and commercial properties due to the high significance of the energy costs at total expenses of most families and business. This study focuses on exploring optimization process of energy costs of a grid-connected hybrid PhotoVoltaic (PV)/Battery/Grid. The profile of a big commercial load located in Brazilian Amazon area is used as an optimization example. The system performance and optimization results are verified by using Hybrid Optimization of Multiple Energy Resources (HOMER).
Abdulrahim Hamed S. Alghamdi, Carlos Henrique Marciano Rodrigues Castro, Ramon Zamora

Efficient Fault Identification Protocol for Dynamic Topology Networks Using Network Coding

This paper considers the problem of fault identification in dynamic topology networks using the time-free comparison model. Here, we introduce an efficient self-diagnosis protocol that can identify faulty nodes in dynamic networks. This protocol can correctly diagnose various fault types including permanent, dynamic, and soft faults. The protocol consists of a testing stage and a disseminating stage. During the testing stage, each node identifies the state of a part of nodes using the time-free comparison model. Afterward, nodes share their views employing a random linear network coding (RLNC) technique in the disseminating stage. The design of the disseminating stage is crucial for diagnosis efficiency. Using RLNC obviates the need for disseminating the views individually, and hence it reduces the number of messages required to diagnose the network. The OMNeT++ simulation has been used to evaluate the performance of the proposed protocol regarding the communication complexity. Results show that the proposed protocol is robust, scalable and energy-efficient.
Hazim Jarrah, Peter H. J. Chong, Nurul I. Sarkar, Jairo Gutierrez

Performance Evaluation of Handover Protocols in Software Defined Networking Environment

Smooth handovers of Mobile Nodes (MN) between different points of attachments to the network ensures seamless connectivity when users move from one place to another. In IP based wireless networks, Mobile IPv6 (MIPv6) protocol manages handover issues, which has evolved with time to take many different forms. In this paper, we explore the softwarization of wireless networks with special regard to mobility management. We modify the legacy mobility management protocols to accommodate Software Defined Networking (SDN) features and measure their performance using simulations. The considered performance indicators include time to complete the handover process and the number of steps required for the same.
Dong-Ru Lee, Shan Jaffry, Syed Faraz Hasan, Yaw-Wen Kuo, Xiang Gui

Dynamic Spectrum Management in 5G: Lessons from Technological Breakthroughs in Unlicensed Bands Use

This paper discusses a number of issues associated with the increasing need to improve the utilization of unlicensed spectrum as a number of new technological advances provide an opportunity to share scarce resources in a dynamic fashion in the future 5G networks. The growth in connected devices via cellular and Wi-Fi networks is being complemented with a significant increase in networked “things” and this proliferation of devices presents a challenge to Spectrum Authorities. We propose that the ultimate purpose of Dynamic Spectrum Management (DSM) is to improve spectrum usage efficiency by fully exploiting spectrum sharing while assuring minimum undesired interference. Our aim is the identification of economic issues that impact the development of efficient markets for 5G networks that rely on dynamic spectrum technologies in the unlicensed spectrum. The paper covers how technological breakthroughs in spectrum access technologies challenge our current understanding of spectrum management. In each case, the contribution of the paper includes policy proposals or more focused regulatory instruments while the concluding section sums up the paper’s key message about the interplay between technology and policy that helps lay out elements that regulators and policy-makers need to attend to when adopting practices that implement Dynamic Spectrum Management in the unlicensed spectrum.
Fernando Beltrán, Sayan Kumar Ray, Jairo Gutiérrez

Dual Sensing Scheduling Algorithm for Wireless Sensor Network Based Road Segment Surveillance

In this paper, a dual sensing scheduling algorithm is proposed which is a modified version of VISA technique for sensing scheduling in road networks where targets can enter from both sides of the road. VISA and similar algorithms are based on the idea of designated entrance points and protection points and are very suitable for military scenarios. In comparison, civilian applications mostly use two-way roads and dual carriageways with entrance points on both ends of the roads calling for a modification of the VISA technique to make it suitable for two-way detection. The proposed algorithm achieves detection on a two-way road by using two parallel scan waves originating from the midpoint sensor on the road segment but in opposite directions. The proposed modification of the VISA algorithm improves the detection time by reducing it to half as compared to VISA but at the cost of decreased network lifetime. The proposed algorithm is also compared to Duty Cycling and Always-Awake schemes.
Farhan Khan, Sing Kiong Nguang

A Clique Based Asymmetric Rendezvous Scheme for Cognitive Radio Ad-Hoc Networks

Cognitive Radio (CR) is a promising technique to enhance the spectrum utilisation by enabling the CR users to opportunistic access the spectrum holes or channels. To exchange spectrum information most of the existing research have utilised a Common Control Channel (CCC). This results channel saturation, extreme transmission overhead of control information, and a point of vulnerability. To address this problem, Channel Hopping (CH) protocols have proposed for enabling Rendezvous (RDV). This paper presents a CH protocol based on clique system, called clique based channel hopping (CCH) for the purpose of RDV establishment. The proposed CCH is a role based blind RDV CH system where sender and receiver generates CH sequence based on h-clique and v-clique respectively. The CCH protocol satisfies the following requirements: (i) guaranteed RDV; (ii) no synchronisation; and (iii) symmetric and asymmetric channel model. Simulation results show that the proposed clique based channel hopping (CCH) scheme outperforms similar CH schemes in terms of average time-to-rendezvous (ATTR) and the degree of overlap in both symmetric and asymmetric channel scenario.
Md Akbar Hossain, Nurul I. Sarkar

The Blockchain Marketplace as the Fifth Type of Electricity Market

This paper tackles today’s unprecedented challenges of enabling and stimulating multiple energy stakeholders to have a more active participation in the smart grid electricity market. The research extends the existing four archetypes of orchestrator-driven business models for the electricity market and proposes a fifth type of electricity market, the Blockchain Marketplace. The key novelty of the paper is to expand the electricity market architecture and design from centralization and pseudo-decentralization to full decentralization, enabled by the blockchain. The study not only broadens the smart grid and electricity market literature but also contributes to the theoretical development of the business model and organization study domains with a systemic approach.
Yueqiang Xu, Petri Ahokangas, Seppo Yrjölä, Timo Koivumäki


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