Online ISSN
1751-8636
Print ISSN
1751-8628
IET Communications
Volume 5, Issue 18, 16 December 2011
Volumes & issues:
Volume 5, Issue 18
16 December 2011
-
- Author(s): Tzung-Shi Chen ; Yuh-Shyan Chen ; Chih-Yung Chang ; Cho-Li Wang
- Source: IET Communications, Volume 5, Issue 18, p. 2595 –2597
- DOI: 10.1049/iet-com.2011.0852
- Type: Article
- + Show details - Hide details
-
p.
2595
–2597
(3)
- Author(s): H. Kim ; X. Yang ; M. Venkatachalam
- Source: IET Communications, Volume 5, Issue 18, p. 2598 –2605
- DOI: 10.1049/iet-com.2011.0103
- Type: Article
- + Show details - Hide details
-
p.
2598
–2605
(8)
In this study, the authors consider the benefits of mobile terminals (MTs) with different access points (APs) for uplink and downlink transmission to conserve MTs’ energy. In traditional cellular networks, an MT is typically associated with a single AP. However, as wireless networks evolve, heterogeneous and/or overlay deployment scenario become viable and an MT can be associated with different APs for uplink and downlink transmission. The authors call this ‘dual APs association’. The authors show that allowing dual APs association provides a significant gain on the uplink system capacity and/or the uplink transmit power savings. As a specific example of the use of dual APs, the authors focus on relay networks and show that considering the relay cost further increases the benefits of this approach. Based on extensive simulations using IEEE 802.16m relay network Evaluation Methodology, the authors demonstrate that dual APs can improve the uplink harmonic capacity by 350% or reduce the uplink transmit power by 7 dB. The authors note, however, that there exists a signalling cost in implementing dual APs association, which needs be overcome to achieve these substantial performance improvements. - Author(s): R. Wang ; J.S. Thompson ; H. Haas ; P.M. Grant
- Source: IET Communications, Volume 5, Issue 18, p. 2606 –2616
- DOI: 10.1049/iet-com.2011.0104
- Type: Article
- + Show details - Hide details
-
p.
2606
–2616
(11)
In this study, the potential of reducing radio base station operational energy consumption is discussed in terms of deploying sleep modes. By periodically switching off the base station transmission, or using fewer transmit antennas, the energy consumption of base station hardware decreases. By delivering less control signalling overhead, the radio frequency energy consumption can also be reduced. Taking the long-term evolution system as an example, up to 90% radiated energy reduction can be obtained in low traffic conditions by employing time-domain optimisation in each radio frame. The optimum on/off duty cycle is derived, enabling the energy consumption of the base station to scale with traffic load. In the spatial domain, an antenna selection criterion is proposed, indicating the most energy-efficient antenna configuration as a function of users' locations and quality of service requirements. Without time-domain sleep modes, using fewer transmitter antennas could outperform full antenna transmission. However, with time-domain sleep modes, using all available antennas is generally the most energy-efficient choice. - Author(s): C. Khirallah ; J.S. Thompson ; H. Rashvand
- Source: IET Communications, Volume 5, Issue 18, p. 2617 –2628
- DOI: 10.1049/iet-com.2011.0111
- Type: Article
- + Show details - Hide details
-
p.
2617
–2628
(12)
In long-term-evolution-advanced (LTE-advanced), heterogeneous deployments of relays, femtocells and conventional macrocells are expected to provide coverage extension and throughput enhancement, while significantly lowering the energy consumption and total-cost-of-ownership (TCO) in cellular networks. This study presents a methodology for estimating the total energy consumption, taking into account the total operational power and embodied energy, and TCO of wireless cellular networks, and in particular provides a means to compare homogeneous and heterogeneous network (HetNets) deployments. The authors introduce realistic energy models and energy metrics based on information available from mobile-network operators (MNOs) and base stations manufacturers. Additionally, up-to-date operational and capital expenditure (OPEX and CAPEX) models are used to calculate TCO of candidate networks. The authors evaluate two scenarios for HetNets, namely a joint macro-relay network and a joint macro–femtocell network, with different relay and femtocell deployments densities. The results obtained show that compared to macro-centric networks, joint macro-relay networks are both energy and cost efficient, whereas joint macro–femtocell networks reduce the networks TCO at the expense of increased energy-consumption. Finally, it is observed that energy and cost gains are highly sensitive to the OPEX model adopted. - Author(s): C. Han and S. Armour
- Source: IET Communications, Volume 5, Issue 18, p. 2629 –2639
- DOI: 10.1049/iet-com.2011.0113
- Type: Article
- + Show details - Hide details
-
p.
2629
–2639
(11)
Mobile communication industries are increasingly contributing to the worldwide energy consumption and CO2 emission. This study addresses a number of key radio resource management (RRM) strategies across PHY and MAC layers for reducing base station energy consumption, as measured by a ‘Joules per bit’ metric. These strategies including power efficient link adaptation, exploitation of multi-user diversity and trading bandwidth for energy efficiency. By collectively taking advantage of those RRM strategies, a multi-user adaptive power and resource allocation algorithm is proposed to ease the power requirements of a base station, while maintaining the same levels of service to the user. The scheduling algorithm is applied to an LTE downlink simulator and its performance is evaluated for various traffic load conditions. The results show that the proposed algorithm achieves a significant energy saving (up to 86%) over a conventional non-energy aware resource allocation scheme. Furthermore, the energy efficiency performance of various multiple antenna techniques is evaluated along with the impact of control signalling overhead. These multiple antenna schemes are then incorporated into the proposed scheduling algorithm and the additional achievable energy savings are quantified. - Author(s): A. Phasouliotis ; D.K.C. So ; W. Prawatmuang
- Source: IET Communications, Volume 5, Issue 18, p. 2640 –2647
- DOI: 10.1049/iet-com.2011.0116
- Type: Article
- + Show details - Hide details
-
p.
2640
–2647
(8)
Energy efficiency has become increasingly important in wireless communications nowadays. Saving energy will not only reduce operating cost but also reduces greenhouse gas emissions, which is important for combating climate change. The authors propose energy-efficient user grouping algorithms to provide power minimisation of grouped multi-carrier code division multiple access (MC-CDMA) and space–time block coding MC-CDMA systems in a cellular environment. Depending on the channel fading conditions, power control is utilised to minimise the total transmitted power under a bit error rate constraint. When the allocation is performed without a fair data rate requirement, the authors provide the optimal solution to the minimisation problem. However, when some fairness is considered, the optimal solution requires high computational complexity. Thus, the authors solve the problem by proposing two suboptimal algorithms. Simulation results illustrate a significantly reduced power consumption in comparison with other techniques. - Author(s): S. Kim
- Source: IET Communications, Volume 5, Issue 18, p. 2648 –2655
- DOI: 10.1049/iet-com.2011.0093
- Type: Article
- + Show details - Hide details
-
p.
2648
–2655
(8)
In view of the remarkable growth in the number of users and the limited network resource, an efficient network management is very important and has been an active area of research over the years. Especially, during wireless network operations, adaptive power control is an effective way to enhance the network performance. In this study, a new online power control scheme is proposed based on the evolutionary game theory. To converge a desirable network equilibrium, the proposed scheme adaptively adjusts a transmit power level in a distributed online manner. For the efficient network management, the online approach is dynamic and flexible that can adaptively respond to current network conditions. With a simulation study, the author demonstrates that the proposed scheme improves the network performance under widely diverse network environments. - Author(s): S. Jeon and Y. Kim
- Source: IET Communications, Volume 5, Issue 18, p. 2656 –2661
- DOI: 10.1049/iet-com.2011.0109
- Type: Article
- + Show details - Hide details
-
p.
2656
–2661
(6)
As Wi-Fi handheld devices providing a variety of data and multimedia services become more widespread, and as the global demand for internet access everywhere rapidly increases, energy-efficient network mobility (NEMO) technology is attracting great attention with respect to the latest research in mobile networking. The previous research relating to energy-efficient networks in mobile networking has focused on routing protocol or topology control. In NEMO, cost-efficient protocol design reduces unnecessary costs because of mobility signalling and packet delivery, and saves limited network bandwidth in both wired and especially wireless, which is one of the important issues of energy efficiency. In this study, the authors propose a cost-efficient proxy router-based NEMO scheme (PR-NEMO) providing efficient mobility management and packet delivery method. In PR-NEMO, a mobile network is formed with a unique ID and the information of mobile network nodes (MNNs) within the mobile network anchored at local mobility anchor (LMA) are distributed to attached mobile access gateway (MAG). The authors analyse the performance of the PR-NEMO with the N-PMIPv6 and the rNEMO in terms of total cost; that is, sum of location update cost and packet-tunnelling cost. Numerical results demonstrate that the PR-NEMO is the most cost-efficient scheme, under various conditions, among the three schemes evaluated. - Author(s): T.-H. Hsu and P.-Y. Yen
- Source: IET Communications, Volume 5, Issue 18, p. 2662 –2672
- DOI: 10.1049/iet-com.2011.0088
- Type: Article
- + Show details - Hide details
-
p.
2662
–2672
(11)
Traditional time division multiple access (TDMA)-based medium access control (MAC) protocols for wireless sensor networks (WSNs), for example, low-energy adaptive clustering hierarchy (LEACH), allocate one time slot for each node within a cluster. For nodes that have no data to send, the radio module is still active. Such approaches drain the precious battery energy. In this study, the authors propose a novel TDMA-based MAC protocol to conserve energy and increase data transmission efficiency of sensors in a cluster-based WSN. In the proposed scheme, nodes that have no data to send can go into sleep mode for energy conserving. On the other hands, nodes that have more data to send can ask the cluster head to allocate more time slots for data transmission. Experiments show that the proposed MAC protocol can have better performance than traditional TDMA-based MAC protocols. - Author(s): N. Erratt and Y. Liang
- Source: IET Communications, Volume 5, Issue 18, p. 2673 –2683
- DOI: 10.1049/iet-com.2011.0118
- Type: Article
- + Show details - Hide details
-
p.
2673
–2683
(11)
In this study, the authors present an energy-efficient data compression protocol for data collection in wireless sensor networks (WSNs). WSNs are essentially constrained by motes’ limited battery power and networks bandwidth. The authors focus on data compression algorithms and protocol development to effectively support data compression for data gathering in WSNs. Their design of compressed data-stream protocol (CDP) is generic in the sense that other lossless or lossy compression algorithms can be easily ‘plugged’ into the proposed protocol system without any changes to the rest of the CDP. This design intends to support various different WSN applications where users may prefer more specific compression algorithms, tailored to the sensing data characteristics in question, to their general algorithm. CDP is not only able to significantly reduce energy consumptions of data gathering in multi-hop WSNs, but also able to reduce sensor network traffic and thus avoid congestion accordingly. The proposed CDP is implemented on the tinyOS platform using the nesC programming language. To evaluate their work, the authors conduct simulations via TOSSIM and PowerTOSSIM-z with real-world sensor data. The results demonstrate the significance of CDP. - Author(s): N.-C. Wang and Y.-K. Chiang
- Source: IET Communications, Volume 5, Issue 18, p. 2684 –2691
- DOI: 10.1049/iet-com.2011.0102
- Type: Article
- + Show details - Hide details
-
p.
2684
–2691
(8)
In wireless sensor networks (WSNs), sink mobility has been drawing more and more attention in recent years. Some approaches suggest that mobile sinks repeatedly propagate packets to notify the potential sources of their latest location information. As a result, frequent location updates from multiple sinks introduce both increased transmission traffic and rapid power expenditure. In order to reduce power consumption and minimise the overhead of frequently propagating packets, the authors propose a power-aware data dissemination (PADD) protocol for grid-based WSNs with mobile sinks. Rather than propagate the query messages from each sink to all sensor nodes to establish data forwarding information, a source constructs a grid structure beforehand so that only the dissemination nodes located at grid points need to acquire forwarding information. A properly grid cell size is determined to ensure that a dissemination node can directly communicate each other with its eight neighbouring dissemination nodes. As a result, a message can traverse not only vertically or horizontally but diagonally as well. Besides, dissemination nodes with the most residual energy are selected for forwarding query and disseminating data to evenly distribute energy load in the sensor field. Simulation results demonstrate the effectiveness of PADD in reducing the energy consumption and prolonging the network lifetime. - Author(s): H. Huang ; G. Hu ; F. Yu ; Z. Zhang
- Source: IET Communications, Volume 5, Issue 18, p. 2692 –2702
- DOI: 10.1049/iet-com.2011.0154
- Type: Article
- + Show details - Hide details
-
p.
2692
–2702
(11)
Energy conservation and interference reduction are the two ultimate goals in the design of network protocols for wireless sensor networks (WSNs). Energy-aware geographic routing has been considered as an attractive routing scheme for energy conservation in WSNs owing to its desirable scalability and simplicity. However, most energy-aware geographic routing protocols seldom consider interference reduction. The authors present an energy-aware interference-sensitive geographic routing (EIGR) protocol, which focuses on minimising the total network energy consumption and reducing interference. EIGR adaptively uses an anchor list to guide data delivery, and selects the minimum-interference link from energy-optimal relay region for data delivery. To further reduce the energy consumption and interference, EIGR adjusts the transmission power of each forwarding node so as just to reach the selected next forwarding node. Simulation results demonstrate that the proposed approach exhibits noticeably higher energy efficiency, shorter end-to-end delay and higher packet delivery ratio compared with other geographic routing protocols. - Author(s): M.-Y. Hsieh
- Source: IET Communications, Volume 5, Issue 18, p. 2703 –2711
- DOI: 10.1049/iet-com.2011.0140
- Type: Article
- + Show details - Hide details
-
p.
2703
–2711
(9)
This study addresses a data aggregation model in hierarchical sensor networks, which provides centralised and distributed clustering mechanisms with evenly distributed heads. The model includes intra-cluster and inter-cluster network operations, whereas nodes report data and residual energy to a sink. Additionally, an energy merging scheme reduces node's storage and communication overheads during the collection of node residual energy. The distributed clustering and data reporting with location-based propagation and cluster-based aggregation delay schemes decrease the probability of communication collision, and increase node energy-saving effects. Based on analyses and simulation results, the energy overhead of the model is sensible, given the current state of sensor nodes, and the network lifetime is prolonged with adaptive multi-hop clusters.
Editorial: Green technologies for wireless communications and mobile computing
Dual access points association in relay networks to conserve mobile terminals' energy
Sleep mode design for green base stations
Energy and cost impacts of relay and femtocell deployments in long-term-evolution advanced
Energy efficient radio resource management strategies for green radio
Energy-efficient user grouping algorithms for power minimisation in multi-carrier code division multiple access systems
Adaptive online power control scheme based on the evolutionary game theory
Cost-efficient network mobility scheme over proxy mobile IPv6 network
Adaptive time division multiple access-based medium access control protocol for energy conserving and data transmission in wireless sensor networks
Compressed data-stream protocol: an energy-efficient compressed data-stream protocol for wireless sensor networks
Power-aware data dissemination protocol for grid-based wireless sensor networks with mobile sinks
Energy-aware interference-sensitive geographic routing in wireless sensor networks
Data aggregation model using energy-efficient delay scheduling in multi-hop hierarchical wireless sensor networks
-
- Author(s): X. Bao ; P. Martins ; T. Song ; L. Shen
- Source: IET Communications, Volume 5, Issue 18, p. 2712 –2720
- DOI: 10.1049/iet-com.2011.0236
- Type: Article
- + Show details - Hide details
-
p.
2712
–2720
(9)
The concept of cognitive radio is to exploit efficiently the spectrum resources by allowing the coexistence of the primary and secondary users in the same bandwidth without interfering the performance of primary users. Three coexisting models (overlay, underlay and interleave) were presented in recent literature. In this study, the authors propose a hybrid cognitive network model with overlay and underlay models, whereby a primary link leases its fractions of transmission time to the secondary users for their cooperation (i.e. these nodes form as a virtual multiple input multiple output (VMIMO) group) under the outage constraints of the primary and secondary systems. A new cooperative protocol between primary and secondary users is presented. The authors attempt to achieve the maximum transmission capacity of the secondary users under the primary and secondary outage constraints, which depend on the secondary density in the cognitive network. This study gives the upper bound density of the secondary transmitters that are modelled as a homogeneous marked Poisson point process. The maximum density is achieved by computing an optimal set of system parameters such as power control factor of the secondary user and the dirty paper coding (DPC) parameter. Simulation results illustrate that the maximum secondary density obtained using VMIMO is superior to that obtained by direct primary transmission. - Author(s): F. Buiati ; L.J.G. Villalba ; D. Corujo ; S. Sargento ; R.L. Aguiar
- Source: IET Communications, Volume 5, Issue 18, p. 2721 –2729
- DOI: 10.1049/iet-com.2010.1012
- Type: Article
- + Show details - Hide details
-
p.
2721
–2729
(9)
In the future mobile Internet, a key challenge is how the content is delivered to the mobile user, especially when there are multiple networks belonging to distinct operators. Knowing the network services and conditions available at each one becomes crucial. In order to store information from several networks and operators, the new IEEE 802.21 standard specifies a Media Independent Information Service (MIIS) supporting various information elements (IEs) that provide network information within a geographical area, with the aim of optimising the handover process. Since next-generation wireless devices are expected to support multiple radio access networks, users will be able to maintain connections when switching from one network to another. This article addresses a general approach towards the deployment of a Hierarchical 802.21 Information Service management infrastructure in a heterogeneous mobile environment. Through an NS-2-based simulation, it is shown that the proposed scheme improves the user experience in terms of MIIS server access time and number of optimal handovers in a random mobility scenario. - Author(s): D. Li
- Source: IET Communications, Volume 5, Issue 18, p. 2730 –2735
- DOI: 10.1049/iet-com.2011.0216
- Type: Article
- + Show details - Hide details
-
p.
2730
–2735
(6)
In this study, the author investigates the outage performance of cognitive relay networks, in which the best relay is selected based on full and partial channel state information, respectively. The author derives exact closed-form expressions for both relay selection schemes, and study their asymptotic performance in terms of the diversity order based on the performance bound analysis. Simulation results are provided to confirm the accuracy of the analytical results, and highlight performance gains provided by the relay selection in cognitive radio networks. - Author(s): A. Mahani ; Y.S. Kavian ; M. Naderi ; H.F. Rashvand
- Source: IET Communications, Volume 5, Issue 18, p. 2736 –2743
- DOI: 10.1049/iet-com.2010.0697
- Type: Article
- + Show details - Hide details
-
p.
2736
–2743
(8)
Study the effects of concurrent voice connections on the performance metrics of communication network such as queue length, waiting time, packets service time and is very important. Mathematical analysis of such network especially with long-tail traffic will help us for a good capacity planning and also lead to an accurate admission control algorithms. In this study a mathematical model of a communication network supporting VoIP and back-ground traffic with long-tail service time is considered. Some problems of previous mathematical models are identified and a new queueing system is proposed in which specifically the coexisting of heavy-tail and voice flows is addressed. The long-tail service time is approximated via hyper-Erlang distribution and also to achieving an accurate performance model a Markov reward model is introduced. The available bandwidth for long-tail distribution varies according to the Markov chain, describing the utilisation factor of voice connection. Numerical results show a comparison between exponential and heavy-tail service time and finally the effects of concurrent voice connections on the service time of heavy-tailed back-ground packets is shown. - Author(s): N.Y. Ermolova and O. Tirkkonen
- Source: IET Communications, Volume 5, Issue 18, p. 2744 –2750
- DOI: 10.1049/iet-com.2010.0777
- Type: Article
- + Show details - Hide details
-
p.
2744
–2750
(7)
This study addresses the problem of theoretical characterisation of memory polynomial systems driven by complex-valued Gaussian signals with real and imaginary components imbalanced with respect to those of the original information signal. In various practical applications, both effects are observed jointly. The authors prove a theorem about a representation of the distorted signal in the form of the sum of two uncorrelated components, one of which is a linearly distorted version of the information signal. The derived results are applied to orthogonal frequency division multiplexing error rate analysis. - Author(s): F. Nadeem ; B. Geiger ; E. Leitgeb ; S.S. Muhammad ; M. Loeschnig ; G. Kandus
- Source: IET Communications, Volume 5, Issue 18, p. 2751 –2759
- DOI: 10.1049/iet-com.2009.0469
- Type: Article
- + Show details - Hide details
-
p.
2751
–2759
(9)
The great potential of free space optics (FSO) communication motivates to use it for future requirement of high bandwidth links. However, the widespread use of this technology has been hampered by the reduced availability because of weather effects. To overcome these shortcomings a back-up link can be used so that the combined hybrid network may achieve carrier class availability. A hybrid, FSO/wireless LAN (WLAN) self-synchronising architecture is presented, which provides transparent connectivity without protocol overhead. The switching from one link to another needs efficient algorithms to achieve the optimal bandwidth utilisation while maintaining availability. Generally, the received signal strength is considered as a parameter for switching between the links. In this study, link selection has been analysed for a variety of algorithms, including filtering and hysteresis, using measured data of fog events. The combination of time and power hysteresis is found to be the optimum solution.
Capacity of hybrid cognitive network with outage constraints
IEEE 802.21 Information Services deployment for heterogeneous mobile environments
Outage probability of cognitive radio networks with relay selection
Heavy-tail and voice over internet protocol traffic: queueing analysis for performance evaluation
Theoretical characterisation of memory polynomial systems with in-phase–quadrature imbalanced Gaussian inputs: application to orthogonal frequency division multiplexing error rate analysis
Comparison of link selection algorithms for free space optics/radio frequency hybrid network
Most viewed content for this Journal
Article
content/journals/iet-com
Journal
5
Most cited content for this Journal
-
A review on security threats, vulnerabilities, and counter measures of 5G enabled Internet‐of‐Medical‐Things
- Author(s): Mohammad Kamrul Hasan ; Taher M. Ghazal ; Rashid A. Saeed ; Bishwajeet Pandey ; Hardik Gohel ; Ala’ A. Eshmawi ; S. Abdel‐Khalek ; Hula Mahmoud Alkhassawneh
- Type: Article
-
Compressive sensing-based coprime array direction-of-arrival estimation
- Author(s): Chengwei Zhou ; Yujie Gu ; Yimin D. Zhang ; Zhiguo Shi ; Tao Jin ; Xidong Wu
- Type: Article
-
Massive MIMO: survey and future research topics
- Author(s): Daniel C. Araújo ; Taras Maksymyuk ; André L.F. de Almeida ; Tarcisio Maciel ; João C.M. Mota ; Minho Jo
- Type: Article
-
Performance analysis of non-orthogonal multiple access in downlink cooperative network
- Author(s): Jinjin Men and Jianhua Ge
- Type: Article
-
Non-orthogonal multiple access schemes with partial relay selection
- Author(s): Sunyoung Lee ; Daniel Benevides da Costa ; Quoc-Tuan Vien ; Trung Q. Duong ; Rafael Timóteo de Sousa Jr.
- Type: Article
