• A realization of integrated satellite-terrestrial communication networks for aeronautical services via joint radio resource management

      Cheng, Yongqiang; Xu, Kai J.; Pillai, Anju; Pillai, Prashant; Hu, Yim Fun; Ali, Muhammad; Ahmed, Adeel (2013)
      Despite air travel has not grown as predicted, air travel is still expected to rise to just less than doubling the current figure by 2030. This creates an urging need to develop more efficient Air Traffic Management (ATM) solutions. Around the globe, research and development initiatives have been launched to modernize the air traffic control infrastructures. These modernized infrastructures will be built around continuous information gathering, sharing and transferring of data between aircraft and air navigation service providers and airports ground infrastructure, which will be difficult for current aeronautical communications systems to handle. As a result, new communication infrastructures are required to manage future aeronautical communication traffic demand. This paper proposes an integrated aeronautical communication architecture consisting of four radio access technologies for communications between aircrafts and ground Aeronautical Telecommunication Network (ATN). The design and implementation of a Joint Radio Resource Management (JRRM) framework to manage these radio resources are discussed. The design is verified by a proof-of-concept JRRM prototype which is developed for the management of radio resource between the Inmarsat Broadband Global Area Network (BGAN) and the Aeronautical Mobile Airport Communication System (AeroMACS).
    • A survey of architectures and scenarios in satellite-based wireless sensor networks: system design aspects

      Celandroni, N.; Ferro, E.; Gotta, A.; Oligeri, G.; Roseti, C.; Luglio, M.; Bisio, I.; Cello, M.; Davoli, F.; Panagopoulos, A.D.; et al. (2013-01)
      This paper is not a survey related to generic wireless sensor networks (WSNs), which have been largely treated in a number of survey papers addressing more focused issues; rather, it specifically addresses architectural aspects related to WSNs in some way connected with a satellite link, a topic that presents challenging interworking aspects. The main objective is to provide an overview of the potential role of a satellite segment in future WSNs. In this perspective, requirements of the most meaningful WSN applications have been drawn and matched to characteristics of various satellite/space systems in order to identify suitable integrated configurations. Copyright (c) 2012 John Wiley & Sons, Ltd.
    • Active distribution networks planning with high penetration of wind power

      Mokryani, Geev; Hu, Yim Fun; Pillai, Prashant; Rajamani, Haile S. (2017-04)
      In this paper, a stochastic method for active distribution networks planning within a distribution market environment considering multi-configuration of wind turbines is proposed. Multi-configuration multi-scenario market-based optimal power flow is used to maximize the social welfare considering uncertainties related to wind speed and load demand and different operational status of wind turbines (multiple-wind turbine configurations). Scenario-based approach is used to model the abovementioned uncertainties. The method evaluates the impact of multiple-wind turbine configurations and active network management schemes on the amount of wind power that can be injected into the grid, the distribution locational marginal prices throughout the network and on the social welfare. The effectiveness of the proposed method is demonstrated with 16-bus UK generic distribution system. It was shown that multi-wind turbine configurations under active network management schemes, including coordinated voltage control and adaptive power factor control, can increase the amount of wind power that can be injected into the grid; therefore, the distribution locational marginal prices reduce throughout the network significantly.
    • Aggregated sensor payload submission model for token-based access control in the Web of Things

      Amir, Mohammad; Pillai, Prashant; Hu, Yim Fun (2015-10-26)
      Web of Things (WoT) can be considered as a merger of newly emerging paradigms of Internet of Things (IoT) and cloud computing. Rapidly varying, highly volatile and heterogeneous data traffic is a characteristic of the WoT. Hence, the capture, processing, storage and exchange of huge volumes of data is a key requirement in this environment. The crucial resources in the WoT are the sensing devices and the sensing data. Consequently, access control mechanisms employed in this highly dynamic and demanding environment need to be enhanced so as to reduce the end-to-end latency for capturing and exchanging data pertaining to these underlying resources. While there are many previous studies comparing the advantages and disadvantages of access control mechanisms at the algorithm level, vary few of these provide any detailed comparison the performance of these access control mechanisms when used for different data handling procedures in the context of data capture, processing and storage. This study builds on previous work on token-based access control mechanisms and presents a comparison of two different approaches used for handling sensing devices and data in the WoT. It is shown that the aggregated data submission approach is around 700% more efficient than the serial payload submission procedure in reducing the round-trip response time.
    • Call admission control in cloud radio access networks

      Sigwele, Tshiamo; Pillai, Prashant; Hu, Yim Fun (2014)
      Over the past decade, wireless communications has experienced tremendous growth, and this growth is likely to multiply in the near future. The proliferation of mobile users and an ever increasing demand for multimedia services has resulted in greater capacity requirements. Radio frequency spectrum is scarce and cannot meet this ever increasing demand and the required Quality of Service (QoS) will no longer be achieved if efficient Radio Resource Management (RRM) solutions are not found. Conventional Radio Access Networks (RAN) have standalone Base Stations (BS) with capacity preconfigured for peak loads. These RANs have high call blocking and dropping rates since BSs resources cannot be shared. Cloud based RANs (C-RAN) have been proposed as a cost and energy efficient way of meeting high capacity demand of future wireless access networks by consolidating BSs to the cloud. Instead of relying on rejection of new call requests due to limited BS resources, C-RAN takes benefit of the cloud elasticity, which allows dynamic provisioning of cloud BS resources. This paper presents a novel C-RAN Call Admission Control (C-RAN CAC) to ensure Grade of Service (GoS) by improving blocking probability and improvement of call waiting times. Call blocking probability, call average waiting time and system utilization are used to evaluate the performance of the proposed CAC algorithm.
    • Cascading permissions policy model for token-based access control in the web of things

      Amir, Mohammad; Pillai, Prashant; Hu, Yim Fun (2014)
      The merger of the Internet of Things (IoT) with cloud computing has given birth to a Web of Things (WoT) which hosts heterogeneous and rapidly varying data. Traditional access control mechanisms such as Role-Based Access schemes are no longer suitable for modelling access control on such a large and dynamic scale as the actors may also change all the time. For such a dynamic mix of applications, data and actors, a more distributed and flexible model is required. Token-Based Access Control is one such scheme which can easily model and comfortably handle interactions with big data in the cloud and enable provisioning of access to fine levels of granularity. However, simple token access models quickly become hard to manage in the face of a rapidly growing repository. This paper proposes a novel token access model based on a cascading permissions policy model which can easily control interactivity with big data without becoming a menace to manage and administer.
    • Elastic call admission control using fuzzy logic in virtualized cloud radio base stations

      Sigwele, Tshiamo; Pillai, Prashant; Hu, Yim Fun (2015)
      Conventional Call Admission Control (CAC) schemes are based on stand-alone Radio Access Networks (RAN) Base Station (BS) architectures which have their independent and fixed spectral and computing resources, which are not shared with other BSs to address their varied traffic needs, causing poor resource utilization, and high call blocking and dropping probabilities. It is envisaged that in future communication systems like 5G, Cloud RAN (C-RAN) will be adopted in order to share this spectrum and computing resources between BSs in order to further improve the Quality of Service (QoS) and network utilization. In this paper, an intelligent Elastic CAC scheme using Fuzzy Logic in C-RAN is proposed. In the proposed scheme, the BS resources are consolidated to the cloud using virtualization technology and dynamically provisioned using the elasticity concept of cloud computing in accordance to traffic demands. Simulations shows that the proposed CAC algorithm has high call acceptance rate compared to conventional CAC.
    • An energy-efficient and scalable slot-based privacy homomorphic encryption scheme for WSN-integrated networks

      Verma, Suraj; Pillai, Prashant; Hu, Yim Fun (2015-04)
      With the advent of Wireless Sensor Networks (WSN) and its immense popularity in a wide range of applications, security has been a major concern for these resource-constraint systems. Alongside security, WSNs are currently being integrated with existing technologies such as the Internet, satellite, Wi-Max, Wi-Fi, etc. in order to transmit data over long distances and hand-over network load to more powerful devices. With the focus currently being on the integration of WSNs with existing technologies, security becomes a major concern. The main security requirement for WSN-integrated networks is providing end-to-end security along with the implementation of in-processing techniques of data aggregation. This can be achieved with the implementation of Homomorphic encryption schemes which prove to be computationally inexpensive since they have considerable overheads. This paper addresses the ID-issue of the commonly used Castelluccia Mykletun Tsudik (CMT) [12] homomorphic scheme by proposing an ID slotting mechanism which carries information pertaining to the security keys responsible for the encryption of individual sensor data. The proposed scheme proves to be 93.5% lighter in terms of induced overheads and 11.86% more energy efficient along with providing efficient WSN scalability compared to the existing scheme. The paper provides analytical results comparing the proposed scheme with the existing scheme thus justifying that the modification to the existing scheme can prove highly efficient for resource-constrained WSNs.
    • Energy-Efficient Cloud Radio Access Networks by Cloud Based Workload Consolidation for 5G

      Sigwele, Tshiamo; Alam, Atm S.; Pillai, Prashant; Hu, Yim Fun (2017-01-15)
      Next-generation cellular systems like fth generation (5G) is are expected to experience tremendous tra c growth. To accommodate such tra c demand, there is a need to increase the network capacity that eventually requires the deployment of more base stations (BSs). Nevertheless, BSs are very expensive and consume a lot of energy. With growing complexity of signal processing, baseband units are now consuming a signi cant amount of energy. As a result, cloud radio access networks (C-RAN) have been proposed as anenergy e cient (EE) architecture that leverages cloud computing technology where baseband processing is performed in the cloud. This paper proposes an energy reduction technique based on baseband workload consolidation using virtualized general purpose processors (GPPs) in the cloud. The rationale for the cloud based workload consolidation technique model is to switch o idle baseband units (BBUs) to reduce the overall network energy consumption. The power consumption model for C-RAN is also formulated with considering radio side, fronthaul and BS cloud power consumption. Simulation results demonstrate that the proposed scheme achieves an enhanced energy performance compared to the existing distributed long term evolution (LTE) RAN system. The proposed scheme saves up to 80% of energy during low tra c periods and 12% during peak tra c periods compared to baseline LTE system. Moreover, the proposed scheme saves 38% of energy compared to the baseline system on a daily average.
    • Energy-efficient privacy homomorphic encryption scheme for multi-sensor data in WSNs

      Verma, Suraj; Pillai, Prashant; Hu, Yim Fun (2015-05-04)
      The recent advancements in wireless sensor hardware ensures sensing multiple sensor data such as temperature, pressure, humidity, etc. using a single hardware unit, thus defining it as multi-sensor data communication in wireless sensor networks (WSNs). The in-processing technique of data aggregation is crucial in energy-efficient WSNs; however, with the requirement of end-to-end data confidentiality it may prove to be a challenge. End-to-end data confidentiality along with data aggregation is possible with the implementation of a special type of encryption scheme called privacy homomorphic (PH) encryption schemes. This paper proposes an optimized PH encryption scheme for WSN integrated networks handling multi-sensor data. The proposed scheme ensures light-weight payloads, significant energy and bandwidth consumption along with lower latencies. The performance analysis of the proposed scheme is presented in this paper with respect to the existing scheme. The working principle of the multi-sensor data framework is also presented in this paper along with the appropriate packet structures and process. It can be concluded that the scheme proves to decrease the payload size by 56.86% and spend an average energy of 8-18 mJ at the aggregator node for sensor nodes varying from 10-50 thereby ensuring scalability of the WSN unlike the existing scheme.
    • Evaluating energy-efficient cloud radio access networks for 5G

      Sigwele, Tshiamo; Alam, Atm S.; Pillai, Prashant; Hu, Yim Fun (2016-02-04)
      Next-generation cellular networks such as fifth-generation (5G) will experience tremendous growth in traffic. To accommodate such traffic demand, there is a necessity to increase the network capacity that eventually requires the deployment of more base stations (BSs). Nevertheless, BSs are very expensive and consume a significant amount of energy. Meanwhile, cloud radio access networks (C-RAN) has been proposed as an energy-efficient architecture that leverages cloud computing technology where baseband processing is performed in the cloud, i.e., the computing servers or baseband processing units (BBUs) are located in the cloud. With such an arrangement, more energy saving gains can be achieved by reducing the number of BBUs used. This paper proposes a bin packing scheme with three variants such as First-fit (FT), First-fit decreasing (FFD) and Next-fit (NF) for minimizing energy consumption in 5G C-RAN. The number of BBUs are reduced by matching the right amount of baseband computing load with traffic load. In the proposed scheme, BS traffic items that are mapped into processing requirements, are to be packed into computing servers, called bins, such that the number of bins used are minimized and idle servers can then be switched off to save energy. Simulation results demonstrate that the proposed bin packing scheme achieves an enhanced energy performance compared to the existing distributed BS architecture.
    • Evaluation of community virtual power plant under various pricing schemes

      Okpako, O.; Rajamani, Haile S.; Pillai, Prashant; Anuebunwa, U.R.; Swarup, K.S. (2016-10-13)
      Technological advancement on the electricity grid has focused on maximizing its use. This has led to the introduction of energy storage. Energy storage could be used to provide both peak and off-peak services to the grid. Recent work on the use of small units of energy storage like battery has proposed the vehicle to grid system. It is propose in this work to have energy storage device embedded inside the house of the energy consumer. In such a system, consumers with battery energy storage can be aggregated in to a community virtual power plant. In this paper, an optimized energy resource allocation algorithm is presented for a virtual power plant using genetic algorithm. The results show that it is critical to have a pricing scheme that help achieve goals for grid, virtual power plant, and consumers.
    • Flight trial demonstration of seamless aeronautical networking

      Plass, S.; Hermenier, R.; Lücke, O.; Depoorter, D.G.; Tordjman, T.; Chatterton, M.; Amirfeiz, M.; Scotti, S.; Cheng, Yongqiang; Pillai, Prashant; et al. (2014-05-19)
      This article presents the in-flight demonstration of a new integrated aircraft communications system combining legacy and future radio technologies. This system, developed and validated under real environmental conditions during flight trials, integrates all the aeronautical service domains within a common IPv6-based aeronautical network. The flight trials were held within the framework of the European SANDRA project at Oberpfaffenhofen, Germany, in June 2013. The presented outcomes emphasize the flexibility and scalability of the developed network and demonstrate the seamless service coverage of the given architecture across different airspace domains.
    • Fusion of Digital Television, Broadband Internet and Mobile Communications Part I: Enabling Technologies

      Chan, Pauline M.L.; Liang, X.; Ong, Felicia Li Chin; Pillai, Prashant (2007)
      It is the first part of a tutorial which aims to provide an introduction to the current state-of-the art of Digital Video Broadcasting standards over satellite and its fusion with mobile and Internet technologies. It provides an overview of the different technologies and issues that facilitates better understanding of the current and future operational scenarios, focusing on the available DVB and IP technologies.
    • Fuzzy based CRRM for load balancing in heterogenous wireless networks

      Ali, Muhammad; Pillai, Prashant; Hu, Yim Fun; Xu, Kai J.; Cheng, Yongqiang; Pillai, Anju (2013)
      The ever increasing user QoS demands and emergence of new user applications make job of network operators and manufacturers more challenging for efficiently optimisation and managing radio resources in radio the radio resources pools of different wireless networks. A group of strategies or mechanisms which are collectively responsible for efficient utilisation of radio resources available within the Radio Access Technologies (RAT) are termed as Radio Resource Management (RRM). The traditional RRM strategies are implemented independently in each RAT, as each RRM strategy considers attributes of a particular access technology. Therefore traditional RRM strategies are not suitable for heterogeneous wireless networks. Common Radio Resource Management (CRRM) or joint radio resource management (JRRM) strategies are proposed for coordinating radio resource management between multiple RATs in an improved manner. In this paper a fuzzy algorithm based CRRM strategy is presented to efficiently utilise the available radio resources in heterogeneous wireless networks. The proposed CRRM strategy balances the load in heterogeneous wireless networks and avoids the unwanted congestion situation. The results such as load distribution, packet drop rate and average throughput at mobile nodes are used to demonstrate the benefits of load balancing in heterogeneous wireless networks using proposed strategy.
    • Fuzzy-Logic Based Call Admission Control in 5G Cloud Radio Access Networks with Pre-emption

      Sigwele, Tshiamo; Pillai, Prashant; Alam, Atm S.; Hu, Yim Fun (2017-09-21)
      Fifth generation (5G) cellular networks will be comprised of millions of connected devices like wearable devices, Androids, iPhones, tablets and the Internet of Things (IoT) with a plethora of applications generating requests to the network. The 5G cellular networks need to cope with such sky-rocketing tra c requests from these devices to avoid network congestion. As such, cloud radio access networks (C-RAN) has been considered as a paradigm shift for 5G in which requests from mobile devices are processed in the cloud with shared baseband processing. Despite call admission control (CAC) being one of radio resource management techniques to avoid the network congestion, it has recently been overlooked by the community. The CAC technique in 5G C-RAN has a direct impact on the quality of service (QoS) for individual connections and overall system e ciency. In this paper, a novel Fuzzy-Logic based CAC scheme with pre-emption in C-RAN is proposed. In this scheme, cloud bursting technique is proposed to be used during congestion, where some delay tolerant low-priority connections are pre-empted and outsourced to a public cloud with a penalty charge. Simulation results show that the proposed scheme has low blocking probability below 5%, high throughput, low energy consumption and up to 95% of return on revenue.
    • A generic and extensible asset model for a semantic collaboration framework

      Amir, Mohammad; Hu, Yim Fun; Pillai, Prashant (2014-02-25)
      Analysis of existing literature reveals the growing need to tackle the issue of unified data dissemination. Where this issue has been given some focus, the outreach has been more or less limited to similar systems (i.e. cross-instance collaboration) and no particular focus has been applied on the problem of exposing this data or knowledge to third parties (i.e. cross-vendor collaboration). This paper proposes an integration of semantic technologies within the Web of Things based on the concept and principles of the Service-Oriented Architecture to realize a distributed and semi-autonomous collaboration framework that is capable of offering cross-vendor information exchange and collaboration facilities. Powered by a semantic engine and exposed as a web application with a RESTful API, the generic framework realizes an extensible knowledge management and exchange system that accounts for the dynamic landscape in business-centric Web of Things applications. Disaster management is taken as a potential application scenario to critically analyse and evaluate the system prototype and show that the asset model for the proposed framework is sufficiently capable of meeting the modern-day and next-generation collaboration needs in a world of ever-increasing cross-vendor information sharing.
    • Improved discrete cuckoo search for the resource-constrained project scheduling problem

      Bibiks, Kirils; Hu, Yim Fun; Li, Jian-Ping; Pillai, Prashant; Smith, A. (2018-08)
      An Improved Discrete Cuckoo Search (IDCS) is proposed in this paper to solve resource-constrained project scheduling problems (RCPSPs). The original Cuckoo Search (CS) was inspired by the breeding behaviour of some cuckoo species and was designed specifically for application in continuous optimisation problems, in which the algorithm had been demonstrated to be effective. The proposed IDCS aims to improve the original CS for solving discrete scheduling problems by reinterpreting its key elements: solution representation scheme, Lévy flight and solution improvement operators. An event list solution representation scheme has been used to present projects and a novel event movement and an event recombination operator has been developed to ensure better quality of received results and improve the efficiency of the algorithm. Numerical results have demonstrated that the proposed IDCS can achieve a competitive level of performance compared to other state-of-the-art metaheuristics in solving a set of benchmark instances from a well-known PSPLIB library, especially in solving complex benchmark instances.
    • Interaction models for profiling assets in an extensible and semantic WoT framework,

      Amir, Mohammad; Hu, Yim Fun; Pillai, Prashant; Cheng, Yongqiang; Bibiks, Kirils (2013)
      This paper addresses interoperability issues in an IoT-based cloud environment consisting of multiple WSN clusters made up of connected objects embedded with smart devices which are fully integrated to the Web, forming the Web-ofThings (WoT). Two levels of interoperability are considered: Device-level interoperability and semantic-level interoperability. Eminent issues relating to device heterogeneity and platform dependencies are resolved by using an OSGi (Open Service Gateway initiative) framework as the software fabric for IoT deployment. However, OSGi alone is not enough to resolve data heterogeneity issues, and even less in providing a semantic mapping of devices and their data streams in a generic deployment. To enable this level of interoperability, a novel system that envisages an all-purpose collaboration framework for the WoT to deliver Sensing and Collaboration as a Service (SeaaS/CaaS) is presented.