Communication networks beyond the capacity crunch Ellis, A. D.; Suibhne, N. Mac; Saad, D. ...
Philosophical transactions of the Royal Society of London. Series A: Mathematical, physical, and engineering sciences,
03/2016, Volume:
374, Issue:
2062
Journal Article
Peer reviewed
Open access
This issue of Philosophical Transactions of the Royal Society, Part A represents a summary of the recent discussion meeting 'Communication networks beyond the capacity crunch'. The purpose of the ...meeting was to establish the nature of the capacity crunch, estimate the time scales associated with it and to begin to find solutions to enable continued growth in a post-crunch era. The meeting confirmed that, in addition to a capacity shortage within a single optical fibre, many other 'crunches' are foreseen in the field of communications, both societal and technical. Technical crunches identified included the nonlinear Shannon limit, wireless spectrum, distribution of 5G signals (front haul and back haul), while societal influences included net neutrality, creative content generation and distribution and latency, and finally energy and cost. The meeting concluded with the observation that these many crunches are genuine and may influence our future use of technology, but encouragingly noted that research and business practice are already moving to alleviate many of the negative consequences.
With the advent of future generation mobile communication technologies (5G), there is the potential to allow mobile users to have access to big data processing over different clouds and networks. The ...increasing numbers of mobile users come with additional expectations for personalized services (e.g., social networking, smart home, health monitoring) at any time, from anywhere, and through any means of connectivity. Because of the expected massive amount of complex data generated by such services and networks from heterogeneous multiple sources, an infrastructure is required to recognize a user’s sentiments (e.g., emotion) and behavioral patterns to provide a high quality mobile user experience. To this end, this paper proposes an infrastructure that combines the potential of emotion-aware big data and cloud technology towards 5G. With this proposed infrastructure, a bimodal system of big data emotion recognition is proposed, where the modalities consist of speech and face video. Experimental results show that the proposed approach achieves 83.10 % emotion recognition accuracy using bimodal inputs. To show the suitability and validity of the proposed approach, Hadoop-based distributed processing is used to speed up the processing for heterogeneous mobile clients.
The rapid evolution in mobile wireless communication networks has generated Heterogeneous Wireless Networks (HWNs), which cover a diverse range of networks (e.g., 2G, 3G, and LTE-A). In HWNs, a ...mobile device supports multiple network interfaces that use different access methods for wireless links. In such an environment, the main challenge is Always Best Connected (ABC), which means that the mobile nodes rank the network interfaces and select the best one at anytime and anywhere according to multiple criteria (application-related criteria, network-related criteria, terminal-related criteria, user-related criteria). In this context, Multi Attribute Decision Making (MADM) techniques present a promising solution for the network interface selection problem. The Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) is one widely adopted MADM method. TOPSIS suffers from ranking abnormalities, e.g., if a low-ranking network (alternative) is disconnected or a new network is discovered, then the order of the higher-ranking networks will change abnormally. These abnormalities can potentially decrease the quality of the results. In this paper, we propose new TOPSIS-based approaches for network interface selection that efficiently tackle the ranking abnormality problem in HWNs. The performance of our methods is evaluated through simulations. The results show that the proposed approaches reduce or completely eliminate the rank reversal, either when networks are disconnected or new networks are connected.
Nowadays, although the data processing capabilities of the modern mobile devices are developed in a fast speed, the resources are still limited in terms of processing capacity and battery lifetime. ...Some applications, in particular the computationally intensive ones, such as multimedia and gaming, often require more computational resources than a mobile device can afford. One way to address such a problem is that the mobile device can offload those tasks to the centralized cloud with data centers, the nearby cloudlet or ad hoc mobile cloud. In this paper, we propose a data offloading and task allocation scheme for a cloudlet-assisted ad hoc mobile cloud in which the master device (MD) who has computational tasks can access resources from nearby slave devices (SDs) or the cloudlet, instead of the centralized cloud, to share the workload, in order to reduce the energy consumption and computational cost. A two-stage Stackelberg game is then formulated where the SDs determine the amount of data execution units that they are willing to provide, while the MD who has the data and tasks to offload sets the price strategies for different SDs accordingly. By using the backward induction method, the Stackelberg equilibrium is derived. Extensive simulations are conducted to demonstrate the effectiveness of the proposed scheme.
The future saturation of the electromagnetic spectrum currently allocated for mobile communications has led the scientific and technical communities to consider the use of the vast millimeter-wave ...frequency band. However, there are technical obstacles limiting the immediate use of this band. In the radio propagation area, there is a research effort to characterize the outdoor urban channel. The developed model described here uses a 2.5 D ray-tracing algorithm based on geometrical optics and uniform theory of diffraction concepts in outdoor environments. The model implements several techniques that could be considered by a future standard of fifth-generation mobile communications for the transmission of ultrawideband signals through line-of-sight (LOS) and non-LOS channels with a high density of scatterers, such as trees, poles, and diffuse scattering by rough building walls. In addition, simulations and comparisons are performed in environments where measurement campaigns were carried out, considering the following metrics: received power, mean delay, root mean square delay spread, and cross-polar discrimination. The comparison between simulation and experimental results shows a good agreement. Possible model impairments are also discussed.
The efficacy of a mobile application to increase connectedness to nature and impart flora/fauna/ecological knowledge was assessed in 747 children in three separate and distinctive parks: a wetland, a ...prairie grassland, and an indoor tropical garden. The mobile application was developed with place-based education in mind. At each park, children were randomly assigned to one of three groups. One group of children toured the park using an application on a mobile device with their chaperones, another group toured the park with an environmental educator and their chaperones, and a third group toured the parks with a paper map and their chaperones. Results showed that the mobile application was just as effective at connecting children to nature as more traditional ways of non-formal environmental education, but the mobile application offered additional benefits such as higher ratings of fun.
Tagging wildlife with transmitters is one of the most widely used techniques for research and monitoring. Knowing the possible impact of attaching transmitters to an animal has always concerned ...researchers; however, most assessments have been directed at the effects of transmitters on behaviour and fitness, and fewer have addressed possible injuries to the individuals. The present study evaluated the physical status of birds tagged with transmitters mounted with a Garcelon‐type backpack harness, from five species of large and medium‐sized soaring raptors in western Europe. The study also assessed the factors determining their duration and outcomes. We sent a survey to the managers of projects involving tagged raptors over a 24‐year period, concerning tracking results and veterinary analyses. We obtained information on 659 birds, of which 196 included clinical evaluation from birds in hand. None of the birds showed marks, injuries or abrasions on their feathers or skin caused by the harness or the transmitter. Therefore, this deployment technique is recommended for soaring birds in general and for others in which the use of a backpack harness is chosen. The duration of the system on the bird depended on the traits of the transmitter, being greater in platform transmitter terminal (PTT) satellites. The device lasted longer in larger species and for a shorter time when tagging nestlings. We propose the need for nestlings to be fitted with harnesses corresponding to the size of their adult conspecifics, distinguishing between males and females. Otherwise, the differential growth between sexes could cause discomfort and more frequent removal attempts of the harness. Our results are especially useful for managers and ethics committees to assess bird welfare risks before issuing official permits.
This paper presents a new adaptive algorithm for joint beamforming and antenna selection in mobile communication systems. Such an algorithm is of particular interest for massive multiple-input ...multiple-output (mMIMO) antenna systems along with limited number of available radio-frequency chains. The proposed algorithm is based on introducing an ℓ0-norm constraint to an established adaptive-projection beamforming optimization scheme. In doing so, a real-time beamforming optimization can be carried out, resulting in a beamforming vector that tends to be sparse. The higher-magnitude elements of such a vector point out to the antenna-array elements that have the largest contribution to the output signal-to-interference-plus-noise ratio (SINR). Consequently, an effective antenna selection can be achieved directly by considering the magnitude of the beamforming coefficients. Simulation results confirm the effectiveness of the proposed algorithm in enhancing the output SINR.
•A new adaptive algorithm for joint beamforming and antenna selection is proposed.•The proposed algorithm is targeted for massive MIMO antenna systems.•A limited number of RF chains is considered.•An ℓ0-norm constraint is used for developing the proposed algorithm.•Simulation results show the effectiveness of the proposed algorithm.
Two bandwidth-enhanced broadband dual-polarized antennas (BEBDPAs) are proposed for 2G/3G/4G wireless communication systems and international mobile telecommunication services. The first BEBDPA is ...composed of two perpendicularly crossed dipoles. Its bandwidth is enhanced by introducing a parasitic loop below the two crossed dipoles and a parasitic disk with four parasitic strips above. The BEBDPA achieves an impedance bandwidth of 64% for reflection coefficients <;-15 dB (1.4-2.75 GHz) with an isolation of 30 dB. The second BEBDPA is based on a pair of crossed dual-dipole elements with a parasitic disk above for bandwidth enhancement, featuring a reduced antenna size. The impedance bandwidth of the second BEBDPA is about 63% (1.4-2.7 GHz) with an isolation of 30 dB.
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