Transactions on Emerging Telecommunications Technologies

Cover image for Vol. 26 Issue 6

Early View (Online Version of Record published before inclusion in an issue)

Edited By: Mischa Dohler

Impact Factor: 1.354

ISI Journal Citation Reports © Ranking: 2013: 31/78 (Telecommunications)

Online ISSN: 2161-3915

VIEW

  1. 1 - 100
  2. 101 - 116
  1. Research Articles

    1. Heterogeneous access class barring with QoS guarantee in machine-type communications

      Xiao Han, Teng Joon Lim and Jie Xu

      Article first published online: 3 JUL 2015 | DOI: 10.1002/ett.2959

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      This paper presents an enhancement to the access class barring (ACB) method of regulating channel access requests in wireless networks with a large number of wireless nodes, such as an M2M network. The basic idea is to give a higher access priority to nodes nearing the end of their packet delivery deadline. The proposed protocol is both simple and practical.

    2. An M2M cognitive MAC protocol for overlaid OFDMA environments

      Daniele Tarchi, Romano Fantacci and Dania Marabissi

      Article first published online: 19 JUN 2015 | DOI: 10.1002/ett.2955

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      Machine to machine (M2M) communications have gained in the last years an increasing interest due to ever growing number of machine-type devices. Even if M2M protocols need of dedicated resources, a new paradigm called cognitive M2M has been recently introduced in order to exploit cognitive/opportunistic radio communications. We propose here a cognitive M2M mechanism, where the primary network is based on the orthogonal frequency division multiple access technique, while the M2M communication-based secondary network uses a novel medium access control technique, named data-aided cognitive technique.

    3. Wireless network power optimisation using relay stations blossoming and withering technique

      Aida Al-Samawi, A. Sali, Liyth Nissirat, Nor Kamariah Noordin, Mohamed Othman and Fazirulhisyam Hashim

      Article first published online: 8 JUN 2015 | DOI: 10.1002/ett.2954

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      This paper investigates the optimal relay station (RS) switching profile in HetNet. Analytical model is developed to identify the necessary parameters to achieve optimal RS switching profile. A simplified fuzzy logic RS sleeping mode is introduced as a solution to the RS optimal switching function. The results show that a significant power saving up to 46 per cent in the HetNet can be achieved by switching on/off the RS only.

    4. Reduction of downlink delay time for heterogeneous users in Fi-Wi indoor networks

      D. DebBarma

      Article first published online: 7 JUN 2015 | DOI: 10.1002/ett.2952

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      Centralized hybrid Fibre-Wireless (Fi-Wi) architecture for indoor has been proposed to combine the benefits of a huge bandwidth availability of fibre with the mobility offered by wireless access. The ubiquitous deployment of Wi-Fi access points (AP) in indoor locations leads to a massive degradation in effective data rates acquired by the users. Thus, a centralized Fi-Wi IEEE 802.11x (where x = a, b, g, n and ac) implementation renders dynamic efficient radio resource management of all the APs co-located at a residential gateway (namely, home communication controller). In this paper, we study the problem of dynamically assigning distributed antennas (namely, cell access nodes) to different APs, such that the network performance measured by the metric of total downlink delay for heterogeneous users is improved significantly. In this paper, we propose a centralised association (CA) algorithm for assigning CANs to APs and prove that the CA algorithm achieves efficient Nash equilibrium solution using coalition game theory approach.

    5. A temporal compressive resource allocation technique for complexity reduction in PLC transceivers

      Guilherme R. Colen, Hugo Schettino, Diogo Fernandes, Lucas M. Sirimarco, Fabrício P. V. de Campos, Weiler A. Finamore, Haniph A. Latchman and Moises V. Ribeiro

      Article first published online: 31 MAY 2015 | DOI: 10.1002/ett.2951

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      A novel resource allocation technique for power line communication is addressed on this paper. It makes use of the high correlation between microslots, existing in the normalized signal to noise ratio, in order to decrease the resource allocation computational complexity. The proposed technique is divided in two blocks: (i) set partition block is responsible to grouping microslots with high correlation and (ii) bit-loading block runs the bit-loading algorithm once for each set.

    6. Request routing through collaborative in-network caching for bandwidth optimization: a methodology

      Yuemei Xu, Zihou Wang, Yang Li, Fu Chen, Tao Lin and Wenjia Niu

      Article first published online: 26 MAY 2015 | DOI: 10.1002/ett.2947

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      A distributed in-network caching model is built to formulate the content placement and request routing in content-centric network, aiming at minimizing the bandwidth cost with strict storage and bandwidth constraints. Simulations evaluated on a real ISP network topology and traffic traces show the proposed model and scheme are superior than the ProbCache and leave copy everywhere schemes.

    7. Delay-aware resource control for device-to-device underlay communication systems

      Junchao Li, Weiwei Xia and Lianfeng Shen

      Article first published online: 26 MAY 2015 | DOI: 10.1002/ett.2949

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      We study delay-aware resource control in device-to-device underlay communication systems with multiple source-destination pairs. We focus on the stability robustness of time-varying system and the guarantee of bounded worst-case delay. Two algorithms respectively based on the large deviation approach and the Lyapunov drift approach are thus presented.

    8. Cubic spline extrapolation for uplink channel quality prediction in LTE-A with carrier aggregation

      Maria A. Lema, Mario García-Lozano and Silvia Ruiz

      Article first published online: 25 MAY 2015 | DOI: 10.1002/ett.2950

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      To assure the correct functioning of other radio resource management procedures, channel state information must be reliable. In the uplink, this is a difficult task. This paper proposes the use of cubic splines and interference cancellation techniques to improve the channel quality information of the user at the evolved node B.

    9. Optimal iSINR-based power control for cognitive satellite terrestrial networks

      Stavroula Vassaki, Marios I. Poulakis and Athanasios D. Panagopoulos

      Article first published online: 15 MAY 2015 | DOI: 10.1002/ett.2945

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      This article deals with the problem of power management for the innovative architecture of cognitive satellite terrestrial networks. A power control scheme for the cognitive satellite terminal is proposed along with a novel interference-based constraint to safeguard the primary terrestrial communication. Both the cases of perfect and imperfect channel estimation are considered, and a protection mechanism is proposed that offsets the channel estimation's uncertainty. Simulation results verify the superiority of the proposed mechanism compared with the well-known water-filling based power control scheme.

    10. Performance analysis of spatial OFDM for pixelated optical wireless systems

      M. Rubaiyat H. Mondal and Kusha Panta

      Article first published online: 14 MAY 2015 | DOI: 10.1002/ett.2948

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      Pixelated optical wireless systems can transmit at high speed by encoding data in transmitted images using spatial orthogonal frequency division multiplexing(spatial OFDM) but are susceptible to a number of limiting factors including defocus, linear fractional misalignment and vignetting. This paper introduces mathematical models to investigate the simultaneous effects of these impairments on the performance of both forms of spatial-OFDM: spatial DC-biased optical OFDM(SDCO-OFDM) and spatial asymmetrically clipped optical OFDM(SACO-OFDM).

    11. Throughput, energy efficiency and interference characterisation of 802.11ac

      Yunze Zeng, Parth H. Pathak and Prasant Mohapatra

      Article first published online: 13 MAY 2015 | DOI: 10.1002/ett.2946

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      In this paper, we present a comprehensive performance characterization of 802.11ac using real experiments. In particular, we identify the impact of utilizing larger channel width on throughput (indoor and outdoor), energy efficiency, and interference. We show that using larger channel width is less energy efficient in general. We also show the throughput unfairness issues in heterogeneous channel width environment. Our findings provide numerous insights on benefits and challenges associated with using 802.11ac in practice.

    12. Outage performance of a network coding aided multi-user cooperative secondary network

      S. B. Mafra, R. D. Souza, J. L. Rebelatto, G. Brante and O. K. Rayel

      Article first published online: 5 MAY 2015 | DOI: 10.1002/ett.2943

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      We evaluate the performance of a network-coded cooperative secondary network in a cognitive radio system under spectrum sharing constraints. The outage probability is analyzed under a given maximum interference constraint set by the primary network as well as by the maximum transmit power limit of the secondary sources. Moreover, we also obtain a closed-form equation for theϵ-outage capacity, that is, the maximum information rate achieved by the secondary sources given a target outage probability.

    13. Introducing a handshake for data dissemination using rateless codes in vehicular ad hoc networks

      Nadia H. Khiadani, Sayed Mostafa Safavi Hemami and Faramarz Hendessi

      Article first published online: 5 MAY 2015 | DOI: 10.1002/ett.2944

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      In this paper, we introduce a non-complicated protocol for data dissemination. The protocol's handshake is based on mathematical calculation of communication time between two vehicles. This protocol has high performance such as low collision and high throughput and can be applied in different types of vehicle traffics (low and dense.)

    14. Performance analysis of space modulation techniques over αμ and κμ fading channels with imperfect channel estimation

      Osamah S. Badarneh and Raed Mesleh

      Article first published online: 28 APR 2015 | DOI: 10.1002/ett.2940

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      Space modulation techniques and their performance over generalized αμ and κμ fading channels with imperfect channel estimation are discussed in this paper. The influence of the fading parameters and the channel estimation error on the system performance are analysed and discussed through representative numerical examples.

    15. Dynamic frame aggregation scheduler for multimedia applications in IEEE 802.11n networks

      Emna Charfi, Cédric Gueguen, Lamia Chaari, Bernad Cousin and Lotfi Kamoun

      Article first published online: 28 APR 2015 | DOI: 10.1002/ett.2942

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      We propose a new scheduler called Dynamic Frame Aggregation (DFA) scheduler for IEEE 802.11n network to achieve a best trade-off in terms of realizing the maximum throughput with the minimum delay for different traffic loads. DFA defines new scheduling metrics such as Urgency delay (UD) and Waiting delay (WD). High priority is given for packets having the lowest UD. Then, the payload size of aggregated frame will be adjusted based on UD of the first sub-frame.

    16. Adaptive workflow scheduling for diverse objectives in cloud environments

      Haoran Ji, Weidong Bao and Xiaomin Zhu

      Article first published online: 23 APR 2015 | DOI: 10.1002/ett.2941

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      An adaptive workflow scheduling algorithm in clouds is proposed to meet the challenge of multi-objectives. The algorithm presents good performance for different objectives, even if the weights of objectives change. The overlaps among multiply objectives are taken into account.

    17. Cloud broker service-oriented resource management model

      Mohammad Aazam and Eui-Nam Huh

      Article first published online: 23 APR 2015 | DOI: 10.1002/ett.2937

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      This work presents cloud broker resource management model. Implemented on Google Cluster trace of 12 000 machines, the model presents resource allocation, pricing and refunding according to the historical record of cloud customers.

    18. Fast object identification with mode switching for coexistence of NFC and RFID

      Chul Wan Park, Ji Hyoung Ahn and Tae-Jin Lee

      Article first published online: 22 APR 2015 | DOI: 10.1002/ett.2939

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      We propose a fast identification protocol for the coexistence of Near Field Communication (NFC) and radio-frequency identification (RFID) systems. When an RFID reader identifies an NFC device in the tag mode, the RFID reader stops identifying RFID tags and reserves the next slot for the NFC device in the proposed scheme. The NFC device changes its mode to the reader mode and identifies an RFID tag nearby at the allocated slot.

    19. Space-interweaving-time-convolutional space–time codes for full-duplex MIMO relay networks

      Yi Liu, Hailin Zhang and Yongzhao Li

      Article first published online: 14 APR 2015 | DOI: 10.1002/ett.2938

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      A space-interweaving-time-convolutional space–time coding scheme is proposed to collect cooperative diversity gain for full-duplex multiple-input multiple-output relay systems. This scheme only needs to cancel partial interference signals and then amplify together with interweaving in space by a power control matrix, where the innovative idea is that the loop signals are not directly cancelled but used for space–time coding. Simulations results show that it can collect most of the diversity gain in multiple-input multiple-output relay networks.

    20. Congestion and overload control techniques in massive M2M systems: a survey

      Lilatul Ferdouse, Alagan Anpalagan and Sudip Misra

      Article first published online: 27 MAR 2015 | DOI: 10.1002/ett.2936

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      The survey presents a critical review of various solution techniques for massive access request problem in cellular machine-type-communication (MTC) systems. A general overview of a typical MTC system, its various applications, architectural requirements, functionalities, services, and features are first discussed. Then, the scenario of overload problem and comparative analysis of different solution methods applicable for radio access and core network of the cellular MTC systems are elaborately described and classified. Lastly, some improvement areas of the existing solutions and possible research directions are presented.

    21. On the impact of user segmentation and behaviour analysis over traffic generation in beyond 4G networks

      Luís Carlos Gonçalves, Pedro Sebastião, Nuno Souto and Américo Correia

      Article first published online: 17 MAR 2015 | DOI: 10.1002/ett.2933

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      An impact model on traffic generation considering subscribers' behaviour beyond 4G is presented. Splitting subscribers into user segments based on traffic behaviour and data-centric services enables mobile operators to predict segment dispersion, stability and churn risk. By considering behavioural grouping, capacity planning over-dimensioning could be reduced, enabling segment-based service differentiation and resource allocation prioritization. The model enables overall reduction of operational and capital expenditure while maximizing return of investment, bringing subscribers additional advantages such as customized services and cost reduction.

    22. A massive MIMO terminal concept based on small-size multi-mode antennas

      P. A. Hoeher and N. Doose

      Article first published online: 12 MAR 2015 | DOI: 10.1002/ett.2934

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      This tutorial proposes a massive MIMO terminal concept based on novel multi-mode antennas that facilitate the chassis or printed circuit board itself as the radiator. Anticipated advantages of the concept besides size reduction are multi-stream processing and beamforming capabilities in mobile terminals. Fundamental examination of the antennas correlation and numerical performance results for link-level simulations support the feasability of the proposed concept.

    23. Maximal flow-level stability of best-rate schedulers in heterogeneous wireless systems

      P. Jacko, E. Morozov, L. Potakhina and I. M. Verloop

      Article first published online: 12 MAR 2015 | DOI: 10.1002/ett.2930

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      We investigate flow-level stability of schedulers in parallel-service wireless systems. We model such system as a multi-class queueing system with multiple preemptive servers, in which flows of different classes randomly arrive and depart once their flow is completed. The channel condition of a flow varies randomly over time. The evolution of the channel condition is assumed to be Markovian and class dependent. We prove that any best-rate scheduler achieves maximal stability.

    24. Towards a smart city based on cloud of things, a survey on the smart city vision and paradigms

      Riccardo Petrolo, Valeria Loscrì and Nathalie Mitton

      Article first published online: 9 MAR 2015 | DOI: 10.1002/ett.2931

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      Cloud-of-thing (CoT) paradigm is expected to play a significant role in the context of smart city. This novel paradigm allows a better management of physically distributed resources to be accomplished. In the context of smart city, CoT can really play the role of enabler of a horizontal integration of various (vertical) silos (i.e. other IoT platforms). The VITAL platform embraces exactly this philosophy, by interpreting the role of a CoT platform.

    25. Multilayer diffusion-based molecular communication

      Saizalmursidi Md Mustam, Sharifah Kamilah Syed Yusof and Samad Nejatian

      Article first published online: 4 MAR 2015 | DOI: 10.1002/ett.2935

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      This paper presents the derivation of a closed-form expression for the mean molecular concentration, channel impulse response, mean number of received molecules, channel time delay, and channel attenuation in a multilayer diffusion-based molecular communication channel. The results show that the higher the diffusion coefficient, the smaller the dispersion of channel impulse response and the shorter the time delay. Doubling the transmission distance increases the time delay fourfold but decreases the channel attenuation by eightfold.

    26. Fast and upper bounded Fano decoding algorithm: queuing analysis

      Khalid A. Darabkh

      Article first published online: 27 FEB 2015 | DOI: 10.1002/ett.2929

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      In this paper, we propose a novel queuing model that describes not only frame arriving and departing processes after getting decoded according to how worse the channel condition is or what is the remaining system power, but also a decoder with a double speed compared with what is the best scrutinized in the literature.

    27. A novel low complexity energy-efficient resource allocation for OFDM systems

      Jafar Kazemi, Mohammad Javad Omidi and Keivan Navaie

      Article first published online: 27 FEB 2015 | DOI: 10.1002/ett.2932

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      For an OFDM system, we propose a novel low complexity energy efficient radio resource allocation scheme based on convex optimization programming. The low complexity scheme provides optimal transmission power of the source and its distribution among subcarriers. The simulation results also indicate that using our proposed method results in a significant improvement in the computational complexity.

    28. A dynamic channel access strategy for underlay cognitive radio networks: Markov modelling and performance evaluation

      Elmira Jalali, Indika A. M. Balapuwaduge, Frank Y. Li and Vicent Pla

      Article first published online: 23 FEB 2015 | DOI: 10.1002/ett.2928

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      This paper proposes a novel underlay channel access strategy for multi-channel cognitive radio networks to enhance secondary network's performance, however, subjected to an interference constraint by the primary network. In the proposed strategy, we consider channel assembling and spectrum adaptation together with partial-channel occupancy, which is characterised by a system configurable parameter, inline image. The system performance is evaluated through Markov modelling for both primary and secondary networks in terms of several system-centric parameters together with a cost against gain assessment.

    29. Interference mitigation and D2D parameter estimation for distributed-control D2D underlay systems

      Minjoong Rim, Seungyeob Chae and Chung G. Kang

      Article first published online: 23 FEB 2015 | DOI: 10.1002/ett.2927

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      Although centralized-control schemes for device-to-device (D2D) underlay communications can produce satisfactory results, they may require a large amount of feedbacks from devices. Such a burden can be alleviated by a distributed-control mechanism in which each D2D selects its own resource without a small-scale control of the cellular network. This paper addresses interference issues in distributed-control D2D underlay systems and presents an interference mitigation technique based on frequency spreading.

    30. Energy efficiency optimisation in full-duplex relay systems

      Yunxiang Jiang, Francis C. M. Lau, Hongbin Chen and Feng Zhao

      Article first published online: 17 FEB 2015 | DOI: 10.1002/ett.2926

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      In this letter, energy efficiency of a full-duplex relay system under the total power constraint and fixed circuitry power consumption is studied. An optimisation problem is formulated towards maximising the system energy efficiency. An algorithm called sequential parametric convex approximation-Dinkelbach is proposed to solve the problem.

    31. Lowest-density MDS array codes for reliable Smart Meter networks

      Magnus Sandell and Filippo Tosato

      Article first published online: 16 FEB 2015 | DOI: 10.1002/ett.2925

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      We introduce a lowest density maximum-distance separable array code that is applied to a Smart Meter network to introduce reliability with low overhead. We show the minimum amount of overhead required to be able to recover from node erasures and explicitly design an optimal array code with lowest density. Furthermore, we consider incomplete networks where all nodes are not connected to each other, and we derive conditions on the minimum node degree that allow lowest density maximum-distance separable codes to exist.

    32. On the ergodic secrecy capacity and secrecy outage probability of the MIMOME Rayleigh wiretap channel

      Andre Saito Guerreiro, Gustavo Fraidenraich and Richard Demo Souza

      Article first published online: 12 FEB 2015 | DOI: 10.1002/ett.2924

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      In this paper, we study the multiple-input multiple-output multiple-eavesdropper wiretap channel in the nonergodic and ergodic scenarios, both with stationary Rayleigh distributed fading channels. For the ergodic scenario, we derive a new closed-form expression for the ergodic secrecy capacity with full channel state information at the transmitter in the high signal-to-nose ratio limit. For the nonergodic scenario, we derive a new closed-form expression for the secrecy outage probability also in the high signal-to-nose ratio limit.

    33. Location-based information transmission systems using visible light communications

      Siu-Wai Ho, Jialong Duan and Chung Shue Chen

      Article first published online: 30 JAN 2015 | DOI: 10.1002/ett.2922

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      We propose a location-based broadcast system facilitating information flow to users. Papers in literature talk about either the security applications of visible light communication or how to build a positioning system. We propose a novel authentication system jointly using them. A mathematical framework is also developed. This paper is the first in using an information-theoretic approach to analyze a positioning system and has charted a new way to look at localization significantly different from the existing literature. Some experimental results are also provided.

    34. Resource allocation and power control based on user grouping for underlay device-to-device communications in cellular networks

      Son Dinh-Van, Yoan Shin and Oh-Soon Shin

      Article first published online: 29 JAN 2015 | DOI: 10.1002/ett.2920

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      We propose novel resource allocation and power control methods for device-to-device (D2D) communications underlaying cellular networks. The proposed method divides D2D pairs into several groups and allows spatially separated D2D users to belong to the same group, so that they can exploit the same resource. An appropriate cellular device is selected to share its uplink resources with the D2D pairs in each group in such a way that an adequate signal-to-interference-plus-noise ratio for both cellular and D2D links can be guaranteed.

    35. Graph-based hybrid hyper-heuristic channel scheduling algorithm in multicell networks

      Bei Dong, Licheng Jiao and Jianshe Wu

      Article first published online: 27 JAN 2015 | DOI: 10.1002/ett.2923

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      This paper proposes a novel graph based hyper-heuristic approach to solve the channel scheduling problem in multicell networks. Effectiveness and superiority of this algorithm are demonstrated by a set of benchmark problems.

    36. Capacity investigation of on–off keying in noncoherent channel settings at low SNR

      Peng Zhang, Frans M. J. Willems and Li Huang

      Article first published online: 18 JAN 2015 | DOI: 10.1002/ett.2921

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      In this work, we investigate the capacity per unit-cost of noncoherent on-off keying for both cases of using soft and hard decisions. It is demonstrated that in phase fading using hard decisions cannot destroy the capacity only if extremely asymmetric inputs are used with a proper threshold. By considering a quasi-static Rayleigh fading scenario where the transceiver has no access to channel, throughput per unit-cost results are developed to explore the tradeoff between power efficiency and channel quality.

    37. QoS-aware ant-based route, wavelength and timeslot assignment algorithm for optical burst switched networks

      Yahaya Coulibaly, George Rouskas, Muhammad Shafie Abd Latiff, M. A. Razzaque and Satria Mandala

      Article first published online: 8 JAN 2015 | DOI: 10.1002/ett.2919

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      Quality of service (QoS)-aware ant-based route, wavelength and timeslot assignment was proposed and evaluated. The results demonstrate that QoS constraints have led to better performance compared with non-QoS constraint ant algorithm. Furthermore, ant algorithm outperforms shortest path algorithm that chooses based on physical distance between source and destination pair.

    38. Bayesian inference and fuzzy inference for spectrum sensing order in cognitive radio networks

      Ahmed Mohamedou, Aduwati Sali, Borhanuddin Ali, Mohamed Othman and Hafizal Mohamad

      Article first published online: 16 DEC 2014 | DOI: 10.1002/ett.2916

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      This research employed Fuzzy Inference and Statistical Inference concepts to generate the most appropriate sensing order decision for cognitive radio systems. The proposed solutions were able to capture intrinsic information to improve scheduling quality. Simulation experiments showed great performance of suggested mechanisms.

    39. LAOF: location-aware opportunistic forwarding scheme in mobile Ad hoc networks

      Jun Tao, Yifan Xu, Le Chang, Chengwei Tan and Xiaoxiao Wang

      Article first published online: 15 DEC 2014 | DOI: 10.1002/ett.2918

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      Considering the random waypoint (RWP) model and Manhattan model, we explore the probabilistic characteristics of the node contact provided by the mobile nodes. Moreover, we propose a location-aware opportunistic forwarding scheme, which exploits the location information of the messages and the node mobility to conduct message forwarding. Then, we construct a simulation environment, integrated with the RWP mobility trace and the city taxis traces.

    40. Kronecker product-based codebook design and optimisation for correlated 3D channels

      Ying Wang, Lisi Jiang and Yongce Chen

      Article first published online: 5 DEC 2014 | DOI: 10.1002/ett.2914

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      This paper first demonstrates that, for correlated 3D channels, the distribution of an optimal beamforming vector is approximately 2D uniform distribution and further proves the matching between the Kronecker product based codebook and the correlated 3D channels. Then a criterion is found to construct the optimal codebook which achieves the lowestImax. Finally, a modified discrete stochastic approximation algorithm is proposed to construct a near-optimal codebook with low complexity and fast convergence.

    41. New results on the sum of Gamma random variates with application to the performance of wireless communication systems over Nakagami-m fading channels

      Imran Shafique Ansari, Ferkan Yilmaz, Mohamed-Slim Alouini and Oğuz Kucur

      Article first published online: 4 DEC 2014 | DOI: 10.1002/ett.2912

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      The probability density function (PDF) and the cumulative distribution function of the sum of L independent but not necessarily identically distributed Gamma variates, applicable to the output statistics of maximal ratio combining receiver operating over Nakagami-m fading channels, are presented in closed form in terms of well-known Meijer's G and Fox's H̄ functions. Further analysis, particularly on bit error rate via a PDF-based approach, is also offered in closed form in terms of Meijer's G, Fox's H̄, and extended Fox's H̄(inline image) functions.

    42. A vehicular network for social services using data dissemination

      Rasool Esmaeilyfard, Nadia H. Khiadani, Faramarz Hendessi and Sayed Mostafa Safavi Hemami

      Article first published online: 4 DEC 2014 | DOI: 10.1002/ett.2911

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      In this study, we focus on the idea of establishing a dynamic vehicular network to manage the social groups and the information of social applications. The design principles and patterns used enable our strategy to manage social groups and handles pivotal functions of information management and dissemination quickly and extensively using different communication schemes. Through this approach, we evaluate this infrastructure based on groups with common spatio-temporal properties and analysing the constant speed mobility in our data dissemination scheme.

    43. Capacity region of the Gaussian doubly dirty two-way channel in the presence of partial side information

      Narges Monemizadeh and Ghosheh Abed Hodtani

      Article first published online: 27 NOV 2014 | DOI: 10.1002/ett.2910

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      This paper presents the capacity region of the Gaussian doubly dirty two-way channel with partial side information known non-causally at the users. In particular, an adaptive outer bound is first derived, followed by a non-adaptive inner bound using lattice strategies and Costa's dirty paper coding. The bounds are then shown to coincide, thus characterizing the capacity of the considered channel.

    44. PBMP: priority-based multi-path packet routing for vehicular ad hoc network system in city environment

      Wei Kuang Lai, Chih Kun Tai, Tin-Yu Wu, Alagan Anpalagan and Jian Zhi Chen

      Article first published online: 25 NOV 2014 | DOI: 10.1002/ett.2909

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      PBMP is a geographic routing protocol. The goal is to achieve high delivery ratio and low end-to-end delay. By collecting real-time traffic flow information, we derive a connectivity probability function to select road intersections efficiently for transmissions. In addition, the data loads are also referred to assist with intersection selections and avoid packet congestions. Furthermore, packets are classified with three priority levels for different transmission strategies. To enhance reliability, multiple paths are constructed to achieve high probability of robust receptions.

    45. Signal and interference alignment via message passing for MIMO interference channels

      Ali Mohammad Fouladgar, Osvaldo Simeone, Seok-Hwan Park, Onur Sahin and Shlomo Shamai (Shitz)

      Article first published online: 20 NOV 2014 | DOI: 10.1002/ett.2907

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      The proposed algorithm tackles the problem via the application of the min-sum message passing algorithm to a factor graph constructed on the interference graph of the network. The approach inherits the advantages of the schemes of returning unitary precoding and equalisation matrices, hence simplifying the task of low-rate feedback to the transmitters and receivers, and of allowing a distributed implementation.

    46. Frame size selection in CSMA-based cognitive radio wireless local area networks

      Najam ul Hasan, Waleed Ejaz and Hyung Seok Kim

      Article first published online: 20 NOV 2014 | DOI: 10.1002/ett.2904

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      In this paper, a CSMA based MAC protocol for Cognitive WLAN based on collision between SUs and collision between SUs and PUs is presented. Based on this protocol, we derive an expression for goodput calculation. We perform optimization to select the frame size to maximize the goodput of the system.

    47. A novel quantized time-domain compressed feedback scheme in coordinated multipoint LTE-advanced systems

      Ying Wang, Jing Xu and Wenxuan Lin

      Article first published online: 18 NOV 2014 | DOI: 10.1002/ett.2906

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      In this paper, we exploit the channel sparsity in time-domain and propose a quantized time-domain compressed feedback scheme. A theoretic upper bound on the rate gaps, with respect to the total feedback overhead, is also derived for our scheme. Furthermore, considering the asymmetry characteristic of the global channel, a branching and bounding based bit allocation strategy among all cooperating cells is designed. Simulation results show that our scheme can significantly reduce the feedback overhead and greatly improve the channel state information reconstruction quality compared with existing feedback schemes.

    48. Multiple-access relay channels with non-causal channel state information at the relay

      Mohammad Osmani-Bojd and Ghosheh Abed Hodtani

      Article first published online: 18 NOV 2014 | DOI: 10.1002/ett.2900

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      In this paper, state-dependent multiple-access relay channel (MARC) with non-causal channel state information is investigated. For the discrete memoryless and Gaussian structures of this model, we develop inner and outer bounds on the capacity region. Next, we show numerically that the achievable rate region of Gaussian MARC with cognition of the relay about interference is larger than the achievable rate region of Gaussian MARC without any knowledge about interference. Also, by numerical examples, we investigate the capacity-achieving cases.

    49. Analogue joint source-channel coding for multiple input multiple output–orthogonal frequency division multiplexing systems

      O. Fresnedo, F. J. Vazquez-Araujo, L. Castedo and J. Garcia-Frias

      Article first published online: 12 NOV 2014 | DOI: 10.1002/ett.2908

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      Different transmission techniques based on analogue joint source-channel coding are explored for the transmission of analogue data over multiple input multiple output frequency-selective channels using orthogonal frequency division multiplexing. Three different alternatives for system optimization are proposed to approach the optimal distortion-cost trade-off depending on the channel knowledge at transmission.

    50. Computationally effective sampling frequency-offset estimation for OFDM-based LTE downlink systems

      Young-Hwan You, Won-Jae Shin, Hyoung-Kyu Song and Jong-Ho Paik

      Article first published online: 9 NOV 2014 | DOI: 10.1002/ett.2903

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      In this paper, we present a low-complexity sampling frequency-offset (SFO) estimation scheme suitable for the 3GPP long-term evolution (LTE) system. To achieve low complexity, the proposed estimation scheme uses a central conjugate-symmetric primary synchronization signal specified in the LTE standard, which eases the SFO estimation at the receiver. Simulations show that the proposed frequency estimation scheme can detect the SFO with higher accuracy and much lower complexity, compared with the conventional estimation schemes.

    51. Quadrature spatial modulation–performance analysis and impact of imperfect channel knowledge

      Raed Mesleh, Salama S. Ikki and Hadi M. Aggoune

      Article first published online: 6 NOV 2014 | DOI: 10.1002/ett.2905

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      In quadrature spatial modulation, the spatial constellation symbols are expanded to in-phase and quadrature components. One component transmits the real part of a signal constellation symbol and the other transmits the imaginary part. As such, inter-channel interference is avoided entirely because the two transmitted data are orthogonal and modulated on the real part and the imaginary part of the carrier signal but with the additional transmission of base-two logarithm of the number of transmit antenna bits.

    52. Investigation of cell association techniques in uplink cloud radio access networks

      Shi Yan, Wenbo Wang, Zhongyuan Zhao and Abana Ahmed

      Article first published online: 4 NOV 2014 | DOI: 10.1002/ett.2894

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      In this paper, we study the cell association techniques in uplink cloud radio access networks. Three received power based cell association techniques are presented and analyzed. To characterize the random deployment of remote radio heads with multiple antenna configuration, stochastic geometry is used to evaluate the proposals' ergodic capacity, and the corresponding closed-form expressions are derived.

    53. Maximum likelihood TOA and OTDOA estimation with first arriving path detection for 3GPP LTE system

      W. Xu, M. Huang, C. Zhu and A. Dammann

      Article first published online: 3 NOV 2014 | DOI: 10.1002/ett.2871

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      The Cramér-Rao lower bounds of the LTE time of arrival and time difference of arrival measurements are computed using the different pilots of the LTE system. The achievable performance of the LTE system is compared with the Federal Communications Commission and 3GPP requirements, and the impact of mobile multipath channels on the measurements is analysed. The proposed adaptive threshold-based first arriving path detection method showed robust performances and can fulfil all 3GPP LTE reference signal time difference and received-transmit (Rx-Tx) time difference measurement requirements under various realistic mobile channels.

    54. Optimisation of cooperative spectrum sensing for cognitive radio networks in the presence of smart primary user emulation attack

      Mohammad Javad Saber and Seyed Mohammad Sajad Sadough

      Article first published online: 31 OCT 2014 | DOI: 10.1002/ett.2885

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      One of common threats to cooperative spectrum sensing is primary user emulation attack. Here, we optimize main parameters involved in cooperative energy detection spectrum sensing. We aim at minimizing the probability of error when energy detection is corrupted by malicious user's attack.

    55. The max–min fair approach on dynamic bandwidth allocation for XG-PONs

      I. Gravalos, K. Yiannopoulos, G. Papadimitriou and E. A. Varvarigos

      Article first published online: 30 OCT 2014 | DOI: 10.1002/ett.2893

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      An XG-PON-oriented dynamic bandwidth allocation (DBA) mechanism is proposed. The DBA implements the max–min fair approach along with an iterative granting scheme that ensures portions of bandwidth for every ONU at each upstream frame. The algorithm aims to minimise the total average packet latency and latency jitter while being fair among the ONUs, irrespectively of their spatial separation.

    56. Kernel canonical correlation analysis for robust cooperative spectrum sensing in cognitive radio networks

      J. Manco-Vásquez, S. Van Vaerenbergh, J. Vía and I. Santamaría

      Article first published online: 30 OCT 2014 | DOI: 10.1002/ett.2896

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      In this paper, we propose a kernel canonical correlation analysis scheme for cooperative spectrum sensing in a cognitive radio scenario where not only noise but also interference is taken into account. It exploits the non-linear correlation among the received signals of each secondary user at the fusion centre. The simulations and experimental results show that our proposal is robust under the presence of interference and obtains a considerable advantage over a conventional energy detector.

    57. A distributed interference alignment algorithm using min-maxing strategy

      M. El-Absi, M. El-Hadidy and T. Kaiser

      Article first published online: 27 OCT 2014 | DOI: 10.1002/ett.2897

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      In this paper, a new iterative interference alignment algorithm is developed to improve the sum-rate performance of K-user MIMO channels. The proposed algorithm is performed by minimizing the interference leakage and maximizing the desired power concurrently, which is called Min-Maxing strategy. The numerical simulations show that the proposed algorithm proffers significant sum-rate improvement in K-user MIMO interference channels compared with the existing algorithms at high SNR regime.

    58. Vehicle to Internet communications using the ETSI ITS GeoNetworking protocol

      Victor Sandonis, Ignacio Soto, Maria Calderon and Manuel Urueña

      Article first published online: 23 OCT 2014 | DOI: 10.1002/ett.2895

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      The GeoNetworking protocol has been standardised by the European Telecommunications Standards Institute Technical Committee Intelligent Transport System to route packets inside vehicular ad hoc networks. This paper analyses the performance of the GeoNetworking protocol focusing on the provision of Internet connectivity to vehicles. We identify sources of performance losses when using the GeoNetworking protocol in this kind of communication and propose different mechanisms to improve its performance.

    59. Designing interference-aware network selection protocol for WLAN mobile devices

      Hyunsoon Kim and Hwangnam Kim

      Article first published online: 23 OCT 2014 | DOI: 10.1002/ett.2890

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      In this paper, interference aware selection mechanism is proposed, which is proved to be well performing compared to other traditional selection schemes in terms of both connection delay and throughput performance after the connection. To evaluate the performance of APs prior to the connection, the mechanism additional uses BSS Load information and takes account of both adjacent and completely overlapping channels to catch the effect of interference of multiple APs.

    60. Tradeoff between storage cost and repair cost in heterogeneous distributed storage systems

      Quan Yu, Kenneth W. Shum and Chi Wan Sung

      Article first published online: 14 OCT 2014 | DOI: 10.1002/ett.2887

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      We propose a heterogenous model for distributed storage systems in which storage nodes have different storage costs and download cost and jointly consider the storage allocation problem, the repair problem and the data retrieval problem. In such a heterogenous distributed storage system, we establish the fundamental tradeoff between system storage cost and system repair cost.

  2. Research Article

    1. A novel contact prediction-based routing scheme for DTNs

      Lichen Zhang, Xiaoming Wang, Junling Lu, Meirui Ren, Zhuojun Duan and Zhipeng Cai

      Article first published online: 10 OCT 2014 | DOI: 10.1002/ett.2889

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      The encounters and separations of two mobile nodes in delay/disruption tolerant networks are modelled by an alternating renewal process model. Based on the model, a novel contact prediction-based routing scheme is proposed, in which the prediction of future contacts of two nodes can be computed with the consideration of the instant contact information such as the previous encounter time and separation time. The extensive simulations validate the efficiency of the proposed routing scheme.

  3. Research Articles

    1. Traffic-aware two-dimensional dynamic network provisioning for energy-efficient cellular systems

      Md. Farhad Hossain, Kumudu S. Munasinghe and Abbas Jamalipour

      Article first published online: 8 OCT 2014 | DOI: 10.1002/ett.2872

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      This paper proposes a novel traffic-aware two-dimensional dynamic network provisioning mechanism for enhancing the energy efficiency in OFDMA-based cellular systems. Proposed scheme, named as joint dynamic sectorisation and switching of base station, adaptively reconfigures cellular access networks by switching BSs as well as sectors between active mode and sleep mode. Effectiveness of the proposed scheme is demonstrated, indicating a substantial energy savings.

    2. Entropy-based opportunistic spectrum access for cognitive radio networks

      Mahdi Pirmoradian, Olayinka Adigun and Christos Politis

      Article first published online: 8 OCT 2014 | DOI: 10.1002/ett.2886

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      The proposed scheme maximum entropy channel access selects appropriate spectrum opportunities based on the usefulness of the idle-channel remaining lifetime estimated through the weighted residual entropy function for the unoccupied channels. The performance of the proposed spectrum decision scheme is evaluated using a wealth of efficiency metrics, namely channel utilisation, channel collision, spectrum handoff rate and collision probability in perfect and imperfect spectrum sensing environments.

  4. Research Article

    1. On prioritised opportunistic spectrum access in cognitive radio cellular networks

      Yong Yao, Alexandru Popescu and Adrian Popescu

      Article first published online: 8 OCT 2014 | DOI: 10.1002/ett.2866

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      The paper is reporting theoretical studies on inter-cell handoff in cellular networks enhanced with cognitive radio communication facility. Markov chains-based modelling approach and simulation validation are reported, and a fuzzy logic-based decision-making algorithm to select the best solution for dealing with the inter-cell handoff of secondary users is suggested as well. The reported results show the feasibility of the suggested solution approach.

  5. Research Articles

    1. Medium access control techniques in M2M communication: survey and critical review

      Fatima Hussain, Alagan Anpalagan and Rath Vannithamby

      Article first published online: 30 SEP 2014 | DOI: 10.1002/ett.2869

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      This article reviews and analyses channel access techniques and resource allocation for emerging Long-Term Evolution-based machine-to-machine networks from medium access point of view. It covers both scheduling and random access methods for massive access of machine-type communication (MTC) devices from various performance metrics perspectives. As the choice of medium access control has a strong influence on the energy efficiency of the network, it is discussed and analysed in detail.

    2. Combining super-orthogonal space-frequency trellis coding, constellation shaping by shell mapping, and OFDM for high data rate broadband mobile communications

      Călin Vlădeanu, Ion Bănică, Bjørn Olav Hogstad, Matthias Pätzold and Corneliu Eugen D. Sterian

      Article first published online: 30 SEP 2014 | DOI: 10.1002/ett.2888

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      We proposed a particular combination of transmission techniques in order to improve the performance of broadband mobile communications systems. We have improved the constellation shaping algorithm by pairing two adjacent orthogonal frequency division multiplexing (OFDM) carrier frequencies in order to apply it only to the OFDM frame transmitted by the first antenna. This automatically results in an equal reduction of the peak-to-average power ratio of the OFDM frame transmitted by the second antenna. Superorthogonal space-frequency trellis coding contributes a coding gain of 4 dB or more.

    3. Joint allocation of uplink and downlink resources for interactive mobile cloud applications

      Jiadi Chen, Kan Zheng, Hang Long and Wenbo Wang

      Article first published online: 22 SEP 2014 | DOI: 10.1002/ett.2867

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      In this paper, the joint uplink and downlink resource allocation problem for interactive mobile cloud applications is considered. The objective is minimizing the application response time subject to the drop rate constraint. A novel traffic model for interactive mobile cloud applications is constructed, on the basis of which the problem is formulated as a constrained Markov decision process and solved with the Q-learning algorithm and value iteration algorithm. In addition, a two-step scheme is proposed to achieve a near-optimal solution with acceptable complexity.

    4. Optimum multi-service access selection over heterogeneous wireless networks

      Johnny Choque, Luis-Francisco Díez, Alberto-Eloy García, Ramón Agüero and Luis Muñoz

      Article first published online: 21 SEP 2014 | DOI: 10.1002/ett.2870

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      This paper proposes a methodology to analyse connectivity over highly heterogeneous wireless networks. We consider a scenario comprising a large number of access elements and services. The framework that has been implemented takes periodic snapshots, each of them used to pose a different optimization problem. We take into account the intention of end users to have a connection, as well as the outcome of the previous problems. This work is assessed with a scenario over which we study different access selection strategies.

    5. Relay selection for two-way opportunistic relaying with outdated Nakagami-m estimates

      Xiaochen Xia, Kui Xu, Wei Xie and Youyun Xu

      Article first published online: 19 AUG 2014 | DOI: 10.1002/ett.2865

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      This paper dedicates on the relay selection (RS) strategies, which aim to optimize the system outage performance of two-way opportunistic relaying protocol with outdated Nakagami-m estimates of channels. The RS schemes with outdated channel state information and the statistical knowledge of channels during the RS procedure are developed and analyzed theoretically. The results show that the proposed schemes not only can provide improvement in outage probability but also can harvest diversity gain compared with the traditional schemes.

    6. Performance evaluation of bluetooth low energy in indoor positioning systems

      David Contreras, Mario Castro and David Sánchez de la Torre

      Article first published online: 17 AUG 2014 | DOI: 10.1002/ett.2864

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      The appearance of the new Bluetooth specification, named Bluetooth low energy (BLE), and the emergence of new popular devices that incorporate it, opens the door to new local positioning system(LPS) wireless solutions based on BLE. We evaluate the viability of BLE for indoor positioning scenarios. In addition, we develop a framework to analyze, understand, and help migrate the previous local positioning system systems, based on other technologies, to BLE. We show experimentally that great performance can be obtained in terms of discovery time and energy consumption.

    7. Energy-efficient resource allocation for amplify-and-forward relaying in OFDM systems

      Jafar Kazemi, Mohammad Javad Omidi and Keivan Navaie

      Article first published online: 17 AUG 2014 | DOI: 10.1002/ett.2862

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      For a multicarrier two-phase amplify-and-forward relaying protocol, we propose an energy-efficient radio resource allocation scheme based on mixed binary integer programming. The proposed scheme provides suboptimal transmit power of the source, a suboptimal set of subcarriers for relaying and optimal transmit power of each subcarrier at the source and relay in the first and second time slots. Simulations indicate that using the proposed method results in a significant improvement in energy efficiency.

    8. Analysis and modelling of resources shared in the BitTorrent network

      Rafael A. Rodríguez-Gómez, Gabriel Maciá-Fernández, Leovigildo Sánchez-Casado and Pedro García-Teodoro

      Article first published online: 12 AUG 2014 | DOI: 10.1002/ett.2859

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      We use a monitoring methodology to extract the time evolution of a sample of 1/256 of all the resources shared in BitTorrent network. We discuss the data obtained from a monitoring process carried out during 3 months, and as a result, we analyse the information of more than 70 000 resources. This analysis is based on four features: geographic dispersion, popularity, sharing duration and availability. Finally, we outline an example application to identify anomalous BitTorrent resources.

    9. Smart primary user emulation in cognitive radio networks: defence strategies against radio-aware attacks and robust spectrum sensing

      M. Haghighat and S. M. S. Sadough

      Article first published online: 12 AUG 2014 | DOI: 10.1002/ett.2848

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      In this paper, we analyze and formulate the destructive effect primary user emulation (PUE) attacker imposes to the CR network, and then, we derive robust cooperative spectrum sensing rules for energy detection spectrum sensing under PUE attacks. We propose a scheme to combat fake signals by maximizing the average cognitive signal to interference plus noise ratio. Numerical results show the superiority and robustness of our proposed method in the presence of smart attackers compared with conventional methods.

    10. A demand-based spectrum orthogonalisation scheme for interference avoidance in LTE-Advanced heterogeneous networks

      Siti M. Mohamad Maharum, Norsheila Fisal, Anthony Lo, Aimi S. A. Ghafar, Faiz Asraf Saparudin and Norshidah Katiran

      Article first published online: 11 AUG 2014 | DOI: 10.1002/ett.2860

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      A centralised and dynamic orthogonal spectrum assignment scheme is proposed to address cross-layer and co-layer interference when deploying closed-access mode femtocells within a macrocell site. Simulation results show that when compared with other spectrum assignments in the literature, the proposed scheme performs remarkably in terms of system throughput and spectrum efficiency because the interference is avoided. The proposed scheme manages to support the entire UEs' transmission in both macrocell and femtocell network layers at the expense of full spectrum utilisation.

    11. QoS-based power allocation for cognitive radios with AMC and ARQ in Nakagami-m fading channels

      Leila Musavian and Tho Le-Ngoc

      Article first published online: 11 AUG 2014 | DOI: 10.1002/ett.2853

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      This paper presents power allocation schemes to maximize the effective capacity of a secondary user communications link using adaptive modulation and coding in an underlay cognitive radio Nakagami-m block-fading environment to meet target quality-of-service requirements in terms of delay-outage probability and packet error rate constraints. The results indicate that automatic repeat request is helpful to significantly reduce the packet loss rate for loose delay constraint. However, automatic repeat request increases the delay and is not effective for stringent delay-outage requirements.

    12. Busy tone-based channel access control for cooperative communication

      Kun Xie, Kexin Xie, Shiming He, Daqiang Zhang, Jigang Wen and Jaime Lloret

      Article first published online: 11 AUG 2014 | DOI: 10.1002/ett.2856

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      To increase the channel utilization, we propose a request to send/clear to send + busy tone media access control scheme. In the scheme, three busy tones are proposed to coordinate the nodes in the network to transmit packets, which is further utilized to solve the hidden terminal and exposed terminal problems in cooperative communications. Based on the proposed busy tone, we propose a distributed relay selection algorithm to select the best relay among candidate relays.

    13. Energy-efficient opportunistic forwarding in multi-hop cellular networks using device-to-device communications

      B. Coll-Perales, J. Gozalvez and V. Friderikos

      Article first published online: 11 AUG 2014 | DOI: 10.1002/ett.2855

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      This work investigates how the adoption and design of opportunistic store, carry and forward mechanisms in multi-hop cellular networks (MCNs) can help importantly decrease the energy consumption for delay tolerant traffic. The study derives an analytical framework to identify optimum configurations of opportunistic MCN forwarding, which is used as a benchmark for the design of a novel context-based opportunistic MCN forwarding scheme that exploits context information provided at low cost by the cellular network.

    14. Energy management strategies for base stations in a smart grid environment

      J. Leithon, S. Sun and T. J. Lim

      Article first published online: 5 AUG 2014 | DOI: 10.1002/ett.2861

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      This paper presents an optimisation framework to minimise the energy bill incurred by a cellular base station in a smart grid environment. The base station is equipped with a limited-capacity battery and a renewable-energy harvester. Offline and online strategies are proposed to minimise its energy expenditures. Simulation results show that these strategies can achieve significant cost savings. Related performance bounds and trade-offs are also derived and validated.

    15. Energy-efficiency maximisation for cooperative and non-cooperative OFDMA cellular networks—a survey

      Álvaro Ricieri Castro e Souza, José Roberto de Almeida Amazonas and Taufik Abrão

      Article first published online: 5 AUG 2014 | DOI: 10.1002/ett.2850

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      This survey deals with techniques for energy efficiency optimisation for non-cooperative and cooperative OFDM(A)-based cellular communication networks. Those EE optimisation techniques have the potential to integrate fourth-generation and fifth-generation (4G and 5G) energy-efficient and spectral-efficient communication systems. Furthermore, research trends in energy efficiency optimisation for cellular systems have been put in perspective, aided by standards and documents for 4G network systems, including specifications and parameters.

    16. Energy efficient resource allocation for quantity of information delivery in parallel channels

      Jean-Yves Baudais, Andrea M. Tonello and Abdallah Hamini

      Article first published online: 5 AUG 2014 | DOI: 10.1002/ett.2858

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      We focus on the transmission of a given number of bits over a set of parallel Gaussian channels with energy constraint, and we minimise either the highest transmission time or the average channel occupancy time. This is a resource allocation problem that is formulated by targeting a certain energy consumption factor, beta, defined as the ratio between the energy required in the asymptotic regime and the energy required to transmit a certain quantity of information with limited resources.

    17. Novel protection strategies for passive optical networks based on ring and bus topologies

      Lafata Pavel

      Article first published online: 25 JUL 2014 | DOI: 10.1002/ett.2846

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      Research ArticleNovel protection strategies for passive optical networks based on ring and bus topologiesLafata Pavel This paper is focused on increasing the network resilience of passive optical networks. The most critical components are usually the optical line termination and optical fibres, the main motivation presented within this paper is focused to improve their resistance. Both presented solutions are based on using dual parenting and the application of asymmetric splitters in order to balance the optical signal levels throughout the entire network, while the main innovation consists in the application of ring and bus topologies.

    18. IQ imbalance estimation and compensation schemes based on time-frequency interferometry for OFDM

      Hikaru Oka, Chang-Jun Ahn, Tatsuya Omori and Ken-ya Hashimoto

      Article first published online: 25 JUL 2014 | DOI: 10.1002/ett.2852

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      A direct-conversion receiver (DCR) can reduce the power consumption and cost. However, a DCR with orthogonal frequency-division multiplex (OFDM) suffers from IQ imbalance. Until this time, many algorithms have been proposed to compensate IQ imbalance. However, the calculation complexity is still a considerable work to achieve the implementation of a DCR. Moreover, an accurate channel identification is also necessary for a DCR. Recently, time-frequency interferometry-OFDM (TFI-OFDM) system has been proposed to achieve an accurate channel identification property with small number of pilot symbols. In this paper, we focus on the feature of TFI and propose a novel IQ imbalance estimation and compensation schemes using TFI-OFDM system. In the proposed system, by using the feature of the TFI pilot symbols, we can identify an IQ imbalance without high calculation complexity. Furthermore, by using subcarrier selection, the influence of the noise power can be reduced. From the simulation results, the proposed scheme can achieve the low complexity for IQ imbalance estimation and compensation without a degradation of the bit error rate performance.

    19. Capacity analysis of power line communication point-to-point and relay channels

      Mohsen Sheikh-Hosseini, Ghosheh Abed Hodtani and Mohammad Molavi–Kakhki

      Article first published online: 25 JUL 2014 | DOI: 10.1002/ett.2843

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      In this paper, we present the capacity analysis of broadband power line communication (PLC) channels exploiting orthogonal frequency division multiplexing and single carrier frequency-domain equalisation techniques in the presence of the impulsive noise. For point-to-point PLC, the tight bounds for differential entropy of the non-Gaussian noise samples, capacity bounds, and a certain capacity theorem were obtained. For PLC relay channel, the achievable rate using partial decode and-forward strategy, max-flow min-cut upper bound and the capacity in two special cases of degraded and reversely degraded were obtained.

    20. Capacity bounds for a Gaussian optical wireless relay channel

      A. D. Raza and S. Sheikh Muhammad

      Article first published online: 9 JUL 2014 | DOI: 10.1002/ett.2847

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      This paper presents the original results for the lower and upper bounds on the capacity of a mean and peak power- constrained Gaussian optical wireless relay channel. The asymptotic behaviour of the bounds is also discussed in high and low signal conditions. It is shown that the gap between the upper and lower bounds does not exceed half a bit when signal- to- noise ratio is high.

    21. A simple near-optimal path selection scheme for multi-hop wireless relay networks based on Viterbi algorithm

      Qimin You, Yonghui Li, Zhuo Chen and Md Shahriar Rahman

      Article first published online: 3 JUL 2014 | DOI: 10.1002/ett.2849

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      In this paper, we proposed a near-optimal path selection scheme for multi-hop wireless relay networks. It draws on the analogy between the distribution of relay nodes of a commonly used relay network model and that of a convolutional code trellis and applies the Viterbi algorithm in selecting a path to maximise the end-to-end signal-to-noise ratio. The proposed scheme can be implemented with low complexity and small-storage requirement and is efficient for large-scale networks with a large number of hops and relays per cluster.

    22. Interference-tolerating transmission protocol design for three-cell systems

      Chunguo Li, Peng Wang, Fan Sun, John M. Cioffi and Luxi Yang

      Article first published online: 17 JUN 2014 | DOI: 10.1002/ett.2844

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      An interference-tolerating protocol is proposed for the multi-cell transmission, where one of the three time slots is successfully saved as compared with the conventional TDMA protocol. In order to tackle the new interference introduced by the proposed protocol, the SINR-based precoder is designed for each base station in the two time slots. Moreover, an adaptive receiver based on the linear MMSE and MMSE-SIC is also applied to further suppress the interference.

    23. You have full text access to this OnlineOpen article
      Coexistence of FTTC and FTTDp network architectures in different VDSL2 scenarios

      F. Mazzenga, M. Petracca, F. Vatalaro, R. Giuliano and G. Ciccarella

      Article first published online: 20 MAY 2014 | DOI: 10.1002/ett.2825

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      In this paper, we evaluate the Very high speed Digital Subscriber Line type 2 (VDSL2) performance in scenarios of coexistence between Fibre–To–The–Cabinet (FTTC) with vectoring and Fibre–To–The–Distribution point (FTTDp) architectures, this latter referred to as 'pre–G.fast' solution. Results show that, to protect VDSL2 FTTC systems, Downstream Power Back Off must be implemented at FTTDp, whereas the investment required to bring the optical fibre to the distribution point could be justified by the improved performance achievable with the FTTDp architecture, even with the VDSL2 band profiles currently used.

    24. On the effect of neural network compensation on MIMO-STBC systems in the presence of HPA nonlinearity

      Oussama Ben Haj Belkacem, Mohamed Lassaad Ammari, Rafik Zayani and Ridha Bouallegue

      Article first published online: 19 MAY 2014 | DOI: 10.1002/ett.2837

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      In this paper, we consider a multiple-input-multiple-output systems with space-time block codes in the presence of high-power amplifier nonlinearity. In order to compensate the high-power amplifier nonlinearity, we propose a new receiver scheme based on a neural network algorithm in conjunction with the maximal-ratio combining technique. By assuming that the residual nonlinearity at the neural network output is Gaussian, we have derived the expression of the effective signal-to-noise ratio. The proposed scheme was analyzed in terms of symbol error rate, error vector magnitude and system capacity.

    25. A low-complexity iterative MIMO detection and decoding scheme using dimension reduction

      Sang-Sik Shin, Hongsoo Choi, Jae-Eun Jang and Ji-Woong Choi

      Article first published online: 16 MAY 2014 | DOI: 10.1002/ett.2839

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      This paper proposed an iterative detection and decoding receiver that can be implemented with low complexity based on spatial stream separation into soft and hard streams when all ordering successive interference cancellation with the modified slicing is employed for hard detection while exhaustive search is used for soft streams. It can provide better trade-off between complexity and performance.

    26. Resource management in indoor hybrid Fi-Wi network

      Q. Bien, R.V. Prasad, K. Chandra, I. Niemieegers and H. Nguyen

      Article first published online: 6 MAY 2014 | DOI: 10.1002/ett.2836

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      The combination of radio-over-fiber and 60 GHz wireless links, which is known as hybrid Fi-Wi, is a promising solution to offer high data rate indoor networking. Because of smaller overlapping area between neighbouring cells, guaranteeing quality of service in this network is highly difficult. In this article, we propose a handoff scheme that utilises movement prediction to reserve bandwidth in only potential target cells before each handoff is initiated. The simulation results show that the proposed scheme performs better than the two other schemes from the literature in terms of the call dropping probability and the call blocking probability.

    27. Efficient multiple antenna–relay selection algorithms for MIMO unidirectional–bidirectional cognitive relay networks

      Ahmad Alsharoa, Hakim Ghazzai and Mohamed-Slim Alouini

      Article first published online: 29 APR 2014 | DOI: 10.1002/ett.2834

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      This paper studies the problem of multiple antenna-relay selection for both unidirectional and bidirectional transmissions under cognitive radio set-up. Practical approaches based on iterative and genetic algorithms are proposed. We investigate the increase of the mutual interference caused by primary transmitter on the system performance in addition to the impact of an erroneous channel state information.

    28. On multiple-access relay channel with common message

      Mohammad Osmani-Bojd and Ghosheh Abed Hodtani

      Article first published online: 21 APR 2014 | DOI: 10.1002/ett.2821

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      In this article, we obtain a general achievable rate region of discrete memoryless multiple-access relay channel (DM-MARC) with common message, via partial DF strategy and regular block Markov encoding/backward decoding. Also, by applying Fano's inequality, we derive an outer bound for DM-MARC with common message. By extending the discrete alphabet results to the continuous alphabet, an inner bound for Gaussian MARC is achieved.

    29. A compressive sensing-based approach to end-to-end network traffic reconstruction utilising partial measured origin-destination flows

      Laisen Nie, Dingde Jiang and Lei Guo

      Article first published online: 21 APR 2014 | DOI: 10.1002/ett.2826

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      In this paper, we propose a novel compressive sensing-based approach to estimate end-to-end network traffic using partial measured origin-destination flows. As a purely data-driven method, we first propose a strategy to select a small subset of the measured origin-destination flows. We then propose an optimal greedy adaptive dictionary learning algorithm in order to make the traffic matrix sparse. Furthermore, we model the traffic matrix estimation problem by a fundamental inference problem and compute this problem by compressive sensing reconstruction algorithms.

    30. You have full text access to this OnlineOpen article
      Self organising cloud cells: a resource efficient network densification strategy

      Talal Alsedairy, Yinan Qi, Ali Imran, Muhammad Ali Imran and Barry Evans

      Article first published online: 14 APR 2014 | DOI: 10.1002/ett.2824

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      Network densification is envisioned as the key enabler for 2020 vision that requires cellular systems to grow in capacity by hundreds of times to cope with unprecedented traffic growth trends being witnessed since advent of broadband on the move. This paper proposes and evaluates a novel dense network deployment strategy for increasing the capacity of future cellular systems without sacrificing energy efficiency and compromising mobility performance. Our deployment architecture consists of smart small cells, called cloud nodes, which provide data coverage to individual users on a demand bases while taking into account the spatial and temporal dynamics of users.

    31. A decision theoretic approach for clustering and rate allocation in coordinated multi-point (CoMP) networks with delayed channel state information

      Yegui Cai, F. Richard Yu and Shengrong Bu

      Article first published online: 13 APR 2014 | DOI: 10.1002/ett.2831

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      We present a decision theoretic approach to the clustering and rate allocation problem in coordinated multi-point with delayed channel state information. Specifically, we model such a system in the framework of networked Markov decision process with delays. We derive an optimal policy with low computation complexity.

    32. QoS-driven spectrum sharing game in cognitive radio systems: a variational inequality approach

      Marios I. Poulakis, Stavroula Vassaki, Athanasios D. Panagopoulos and Philip Constantinou

      Article first published online: 26 MAR 2014 | DOI: 10.1002/ett.2823

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      This paper proposes a quality of service (QoS)-driven spectrum sharing scheme for interweave cognitive radio systems. The problem of licensed spectrum sharing among secondary users (SUs) with different QoS requirements is formulated as a non-cooperative game with a view of maximising each SU's effective capacity, subject to the coupled constraint of the available bandwidth. This leads to a generalised Nash equilibrium problem, which is solved by applying the variational inequality framework. Simulation results confirm the importance of incorporating the QoS factor in spectrum sharing studies.

    33. Power-aware routing in networks with quality of services constraints

      Gongqi Lin, Sieteng Soh, Kwan-Wu Chin and Mihai Lazarescu

      Article first published online: 25 MAR 2014 | DOI: 10.1002/ett.2822

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      In this paper, we propose a new approach, that is, Multiple Paths by Shortest Path First, to find the minimum set of operational devices, that is, routers and cables, which can be used to route a given set of traffic demands while satisfying users' maximum link utilization and path length constraints. Simulation results show that Multiple Paths by Shortest Path First runs on average 99% faster while improving its power savings by 5% on tested topologies and traffic demands, as compared to GreenTE.

    34. Design of a medical-grade QoS metric for wireless environments

      Kyung-Joon Park, Hyung-Ho Lee, Sunghyun Choi and Kyungtae Kang

      Article first published online: 24 MAR 2014 | DOI: 10.1002/ett.2819

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      In this letter, we introduce medical-grade quality of service (QoS) for wireless healthcare applications. As a prevailing application, we present a medical-grade QoS metric for wireless electrocardiogram(ECG) transmission. The introduced QoS metric, called weighted diagnostic distortion, can properly evaluate medical-grade QoS by reflecting the main diagnostic features of an ECG signal.

    35. Reciprocally opportunistic spectrum access

      Xianfu Chen, Honggang Zhang, Marko Höyhtyä, Mika Lasanen and Jacques Palicot

      Article first published online: 10 MAR 2014 | DOI: 10.1002/ett.2810

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      This paper studies opportunistic spectrum access in cognitive radio networks. The non-cooperative secondary users are enabled to conjecture how other competing secondary users behave. Based on the conjectural belief model, the best response learning and the gradient ascent learning algorithms are proposed for achieving the optimal spectrum access strategies. Simulation results show that the performance of the proposed algorithms outperforms the existing multi-agent Q-learning scheme the and Nash equilibrium scheme.

    36. p-Cycle configuration possibilities over DRDA networks

      Jerzy Domżał, Robert Wójcik, Andrzej Jajszczyk, Pedro M. Santiago del Río, José Alberto Hernández and Javier Aracil

      Article first published online: 10 MAR 2014 | DOI: 10.1002/ett.2813

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      A resilience analysis of p-cycle configurations for Double Rings with Dual Attachment (DRDAs) architectures is presented in this work. DRDAs are composed of two rings with corresponding nodes connected by two separated links. There are several possible configurations of p-cycles, which may be used in DRDAs for improving link or node protection upon link failure. The values of the parameters Mean Time To Failure and Mean Time To Disconnection are analysed in the paper to show the best choice of p-cycles in DRDAs architectures.

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