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It has been a significant issue to satisfy the rapidly growing data traffic with the limited wireless radio resources. Licensed-assisted access to unlicensed spectrum (e.g., LAA) brings hope for the service provider (SP) to mitigate the deficiency of radio resources. This work contributes on designing a pricing model in a licensed and unlicensed coexisting network, modelled as a two-sided market with content providers (CPs) and end users (EUs) at the SP's two sides. A premium content delivery deal is further designed via the optimal auction in order to efficiently allocate the scarce radio resources for the CPs with higher traffic load and QoS requirement. Thus, the SP and CPs form a prioritized spectrum game, and the SP and EUs form a radio access subscription game. By backward induction, we derive the basic delivery price and the premium delivery price to CPs, the reservation price, and the LTE-only and LAA subscription prices to EUs. Analysis shows that all players benefit from the premium delivery deal and co-existence of unlicensed LTE. When the unlicensed spectrum becomes reliable, all players’ payoffs and the subscription ratio increase. In addition, the impact of the subsidies and technology heterogeneity are also addressed in this article. [ABSTRACT FROM AUTHOR]

A user changes its serving cell if the quality of experience (QoE) provided by the current serving cell is not satisfactory. Since users reselect cells to increase their QoEs selfishly, the system resource efficiency can be deteriorated and a system can be unstable if users are not driven to cooperate appropriately. In this paper, inspired by the minority game (MG) model, we design a UE-initiated cell reselection policy. The MG has a salient characteristic that the number of players who win the game converges to a prespecified value even though players act selfishly without knowing the actions taken by the other players. Using the MG model, we devise a rule by which each UE plays a cell reselection game. We also design a criterion that a system controller uses to determine the result of a game and public information sent by a system controller to induce implicit cooperation among UEs. The simulation results show that compared with noncooperative method the proposed method increases not only the system performance, such as cell load balance index and system utility, but also the performance of UEs in terms of a downlink data rate and an outage probability received from a system. [ABSTRACT FROM AUTHOR]

This article presents a converged 5G network infrastructure and an overarching architecture to jointly support operational network and end-user services, proposed by the EU 5G PPP project 5G-XHaul. The 5G-XHaul infrastructure adopts a common fronthaul/backhaul network solution, deploying a wealth of wireless technologies and a hybrid active/passive optical transport, supporting flexible fronthaul split options. This infrastructure is evaluated through a novel modeling. Numerical results indicate significant energy savings at the expense of increased end-user service delay. [ABSTRACT FROM AUTHOR]

Considering a multicell network for the secure wireless information and power transfer, this paper studies the joint design of transmit beamformers at the base stations (BSs) and receive signal splitting ratios at the end users’ equipment (UE). The primary concern in this work is the network internal security, where there may be a single multiantenna eavesdropper or there is a risk that any near user may accidentally eavesdrop on the received signal of any far user. The objective is to maximize the minimum secrecy user rate under BS transmit power and UE minimum harvested energy constraints. New path-following algorithms are proposed for computational solutions of these difficult nonconvex optimization problems. Each iteration involves one simple convex quadratic program. Numerical results confirm that the proposed algorithms converge quickly after few iterations having a low computational complexity. [ABSTRACT FROM AUTHOR]

Near Field Communication (NFC) enables bidirectional wireless proximity communication between mobile handsets. From an end user point of view, mobile NFC services are expected to replace plastic cards (for payment, ticketing, transport, etc.) by bringing improved convenience and functionality. SIM cards have been used to secure the data and applications that implement mobile NFC services. A total of 300 commercial and pilot SIM-based mobile NFC service initiatives have been reported in 2015. However, their deployment is so complex that no commercial solution has succeeded in reaching out the mass market with few exceptions in special institutional settings (e.g. Japan). Although particularly urgent to the telecom industry, existing scientific research provides limited explanations to why these initiatives are not succeeding. We present a framework that identifies twenty-six factors that hinder the success of SIM-based mobile NFC service deployments. [ABSTRACT FROM AUTHOR]

Web Service Mismatch is a major aspect of web mashup problem. To reduce burden of resolving the mismatch for end-users, the approaches proposed in the literature used a mapping solution to resolve service mismatch. However, without structural information, these approaches would lead to inaccuracy. Here, we propose a structure-based data-mediation approach to improve accuracy. We model service mismatch problem as sub-tree homeomorphism problem and use approximate labelled sub-tree homeomorphism algorithm to resolve the mismatch. The paper presents a case to explain how data-mediation works and solves ambiguity caused by other approaches. We also conduct related tests to evaluate our work. [ABSTRACT FROM AUTHOR]

To this date, although a rich surge of research studies have been conducted on Wireless Mesh Networks (WMNs), still impartial distribution of network resources is one of the open issues in this area. In WMNs, stations that are more hops away from the gateway nodes generally suffer from higher throughput degradation and delay. One of the key reasons for the occurrence of such an incident is the existing limitations in MAC layers of wireless technologies. In this paper, a thorough solution based on an adaptive rate allocation mechanism is proposed to alleviate the fairness issues of WMNs. It is important to note that the presented solution is independent from MAC and underlying layers. This property differentiates it from many other related works on addressing fairness problems in WMNs. Furthermore, the ability of traffic control over UDP and TCP streams, supporting multi-radio mesh routers and restriction of internal greedy traffic within WMNs can be regarded as the main advantages of the offered solution in comparison to the earlier related works. For assessment and evaluation of the proposed scheme, several experiments have been carried out through real testbed environment. The consistency of the represented results substantiates the efficiency of the proposed mechanism in terms of addressing starvation issues and fairness provisioning for end-users of WMNs. [ABSTRACT FROM AUTHOR]

Wireless communication is a trend nowadays for the industrial environment. A number of different technologies have emerged as solutions satisfying strict industrial requirements (e.g., WirelessHART, ISA100.11a, WIA-PA). As the industrial environment presents a vast range of applications, adopting an adequate solution for each case is vital to obtain good performance of the system. In this context, the routing and scheduling schemes associated with these technologies have a direct impact on important features, like latency and energy consumption. This situation has led to the development of a vast number of routing and scheduling schemes. In the present paper, we focus on the WirelessHART technology, emphasizing its most important routing and scheduling aspects in order to guide both end users and the developers of new algorithms. Furthermore, we provide a detailed literature review of the newest routing and scheduling techniques for WirelessHART, discussing each of their features. These routing algorithms have been evaluated in terms of their objectives, metrics, the usage of the WirelessHART structures and validation method. In addition, the scheduling algorithms were also evaluated by metrics, validation, objectives and, in addition, by multiple superframe support, as well as by the redundancy method used. Moreover, this paper briefly presents some insights into the main WirelessHART simulation modules available, in order to provide viable test platforms for the routing and scheduling algorithms. Finally, some open issues in WirelessHART routing and scheduling algorithms are discussed. [ABSTRACT FROM AUTHOR]

In a wireless world, users can establish ad hoc virtual connections between devices that are unhampered by cables. This process is known as spontaneous device association. A wide range of interactive protocols and techniques have been demonstrated in both research and practice, predominantly with a focus on security aspects. In this article, we survey spontaneous device association with respect to the user interaction it involves. We use a novel taxonomy to structure the survey with respect to the different conceptual models and types of user action employed for device association. Within this framework, we provide an in-depth survey of existing techniques discussing their individual characteristics, benefits, and issues. [ABSTRACT FROM AUTHOR]

Wireless multimedia sensor networks (WMSNs) have an increasing variety of multimedia-based applications including image and video transmission. In these types of applications, multimedia sensor nodes should ideally maximize perceptual quality and minimize energy expenditures in communication. For the required perceptual quality to be obtained, quality-aware routing is a key research area in WMSNs. However, mapping the system parameters to the end user's perceptual quality-of-service measures is a challenging task because of incomplete identification metrics. Unfortunately, unless disputable assumptions and simplifications are made, optimal routing algorithm is not tractable. In this paper, we propose a novel image transmission framework to optimize both perceptual quality and energy expenditure in WMSNs. Our framework aims to provide acceptable perceptual quality at the end user by using an analytical distortion prediction model that is able to predict the image distortion resulting from any given error pattern. The innovation of the proposed scheme lies in the combined use of a content-aware packet prioritization with an energy-aware and quality-aware routing protocol, named as image quality-aware routing. Additionally, it does not only propose an energy-efficient route selection policy but also manages the network load according to the energy residues of nodes, thus leading to a great energy economy. The results reveal that the framework is capable of identifying true metrics for mapping required image quality to network parameters. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In Broadband Wireless Access (BWA) networks, provisioning of Quality of Service (QoS) is absolutely essential for real time and non real time services. Congestion in these networks can lead to deterioration in QoS experienced by the network users. Congestion avoidance is rarely considered to ensure the QoS of wireless connections. Efforts are mainly aimed at reducing the overload once it has occurred. To avoid congestion at the base station in WiMAX networks, the WiMAX Fair Intelligent Congestion Control (WFICC) was proposed to ensure the traffic is scheduled in such a way that the base station output buffer operates around a target operating point without violating the QoS requirements of connections. The aim of this paper is to investigate WFICC thoroughly and evaluate its performance in terms of throughput, delay and jitter for different Classes of Services (CoSs) under various parameter settings of the algorithm. A detailed and comprehensive simulation study on various settings of parameters is performed in ns-2. The results show that WFICC performs excellently in allocating resources fairly among Class of Services (CoSs) and also preserves their QoS requirements. Furthermore, WFICC is robust and easily adapted to various traffic conditions. [ABSTRACT FROM AUTHOR]

New 3D video applications and services are emerging to fulfill increasing user demand. This effort is well supported by the increasing 3D video content including user generated content (e.g., through 3D capture/display enabled mobile phones), technological advancements (e.g., HD 3D video capture and processing methods), affordable 3D displays, and standardization activities. However, not much attention has been given to how these technologies, along the end-to-end chain from content capture to display, affect user perception and whether the overall experience of 3D video users is satisfactory or not. 3D video streaming also introduces artifacts on the reconstructed 3D video at the receiver end, leading to inferior quality and user experience. In this article we present and discuss in detail how artifacts introduced during 3D video streaming affect the end-user perception and how we could use realtime quality evaluation methodologies to overcome these effects. The observations presented can underpin the design of future QoE-aware 3D video streaming systems. [ABSTRACT FROM PUBLISHER]

Cognitive radio networks hold the key to achieving better radio bandwidth utilization and improving the quality of wireless applications. The next step in this fast emerging paradigm is the multi-hop cognitive radio network. Well designed multi-hop cognitive radio networks can provide high bandwidth efficiency by using dynamic spectrum access technologies as well as provide extended coverage and ubiquitous connectivity for the wireless end users. However, the special features of multi-hop cognitive radio networks also raise several unique design challenges. In this article, we survey these unique challenges and open research issues in the design of multi-hop cognitive radio networks as well as discuss potential approaches to address these challenges. This article specifically focuses on the medium access control (MAC) and network layers of the multi-hop cognitive radio protocol stack. Issues considered include efficient spectrum sharing, optimal relay node selection, interference mitigation, end-to-end delay, etc. [ABSTRACT FROM PUBLISHER]

With the diffusion of cloud services, they are becoming an alternative to traditional information technology (IT). Despite the importance of cloud services, relatively few studies have been devoted to an empirical examination of the switching behavior from traditional IT to cloud services at the individual level. Therefore, this study attempts to explore the switching factors (i.e. switching enablers and switching inhibitors) and to empirically examine the relationships between those and users’ intention to switch to cloud services, based on the two-factor theoretic perspective. This study uses a longitudinal design to get survey data from undergraduate students at two universities in Korea in the context of IT switching to Google Apps settings. According to our findings, this study found that users’ switching intention to cloud services was not only positively influenced by expected switching benefits whose antecedents are omnipresence of cloud services and collaboration support, but also negatively influenced by expected switching costs whose antecedents are satisfaction with incumbent IT and breath use of inclement IT. The impacts of switching benefits and costs on switching intention were also positively moderated by end users’ personal innovativeness. [Copyright &y& Elsevier]

Mobile broadband has opened the possibility of a rich variety of services to end users. Broadcast/multicast of multimedia data is one such service which can be used to deliver multimedia to multiple users economically. However, the radio channel poses serious challenges due to its time‐varying properties, resulting in each user experiencing different channel characteristics, independent of other users. Conventional methods of achieving reliability in communication, such as automatic repeat request and forward error correction do not scale well in a broadcast/multicast scenario over radio channels. Fountain codes, being rateless and information additive, overcome these problems. Although the design of fountain codes makes it possible to generate an infinite sequence of encoded symbols, the erroneous nature of radio channels mandates the need for protecting the fountain‐encoded symbols, so that the transmission is feasible. In this article, the performance of fountain codes in combination with convolutional codes, when used over radio channels, is presented. An investigation of various parameters, such as goodput, delay and buffer size requirements, pertaining to the performance of fountain codes in a multimedia broadcast/multicast environment is presented. Finally, a strategy for the use of ‘convolutional fountain’ over radio channels is also presented. [ABSTRACT FROM PUBLISHER]

Abstract: The inherent complexity of modern communication networks, whose performance depends on a variety of aspects, makes almost impossible the assessment of the quality of service experienced by the final user by means of analytical investigations. Apart from the realization of real testbeds (which has often prohibitive costs), simulation is the only feasible way to gain an insight into the performance provided to the final user. Unfortunately, publicly available network simulators generally adopt simplified approaches to model the physical layer behavior of supported technologies. On the other hand, the realization of a home made simulator is quite a difficult task, especially when wireless technologies are concerned, which require an accurate modelling of propagation phenomena. In this paper several strategies are presented which are aimed at reducing the burden of physical layer simulations within the context of network simulations; their characteristics, with advantages and lacks are thoroughly discussed. [Copyright &y& Elsevier]

The usability of mobile technology has been found to affect the attitudes of users and their willingness to use it, and furthermore to influence the effectiveness of communication. Accordingly, when mobile technology is developed as a communication medium, the product should be designed to be easy to operate and fit into users' everyday lives. This would mean that more people would be willing to adopt the technology, resulting in more effective communication. [ABSTRACT FROM AUTHOR]

We consider a scheduled orthogonal frequency division multiplexed (OFDM) wireless cellular network where the channels from the base-station to the mobile users undergo flat fading. Spectral resources are to be divided among the users in order to maximize total user utility. We show that this problem can be cast as a nonlinear convex optimization problem, and describe an O(n) algorithm to solve it. Computational experiments show that the algorithm typically converges in around 25 iterations, where each iteration has a cost that is O(n), with a modest constant. When the algorithm starts from an initial resource allocation that is close to optimal, convergence typically takes even fewer iterations. Thus, the algorithm can efficiently track the optimal resource allocation as the channel conditions change due to fading. We also show how our techniques can be extended to solve resource allocation problems that arise in wideband networks with frequency selective fading and when the utility of a user is also a function of the resource allocations in the past. [ABSTRACT FROM AUTHOR]

Late last autumn, automation end-users in the US were asked in an Internet poll which new technologies they think will have the greatest impact for their businesses in the next few years. Far and away the leading contender cited by about 20 per cent of respondents was the adoption of wireless, with cable-free I/O, Ethernet, control, networking and Fieldbus among the specific examples. This is an explicit indication of industry's growing appetite for wireless, which is increasingly being seen as a strategic enabling technology: doing away with wires offers greater workforce mobility, better network flexibility and access to remote or difficult locations. There are also potentially huge savings in cabling costs a key issue for the process industry, for example, which has been one of the earliest adopters of wireless technology. [ABSTRACT FROM AUTHOR]

The increased demand for multimedia services by mobile end users in recent years have driven both Broadcast and Wireless Network operators to develop new systems and architectures for the deployment of such services. The proposed solutions are nonetheless limited either in terms of QoS or Capabilities to deliver new interactive services. This paper highlights strengths and drawbacks of the existing technologies in terms of QoS, Security and Mobility. In order to fill the gap between current solutions we propose a new architecture that builds itself on the synergies created by a heterogeneous network made of existing delivering technologies, such as 3GPP/MBMS and DVB, where services can be delivered to end-users in the most appropriate way for end-users and operators alike. A prototype implementation is further described. [ABSTRACT FROM AUTHOR]

The wireless mesh network is an emerging technology that provides high quality service to end users as the "last mile" of the Internet. Furthermore, multicast communication is a key technology for wireless mesh networks. Multicast provides efficient data distribution among a group of nodes. However, unlike other wireless networks, such as sensor networks and MANETs, where multicast algorithms are designed to be energy efficient and to achieve optimal route discovery among mobile nodes, wireless mesh networks need to maximize throughput. This paper proposes two multicast algorithms: the Level Channel Assignment (LCA) algorithm and the Multichannel Multicast (MCM) to improve the throughput for multichannel and multi-interface mesh networks. The algorithms build efficient multicast trees by minimizing the number of relay nodes and total hop count distances of the trees. The algorithms use dedicated channel assignment strategies to reduce the interference to improve the network capacity. We also demonstrate that using partially overlapping channels can further diminish the interference. Furthermore, additional interfaces help to increase the bandwidth, and multiple gateways can further shorten the total hop count distance. Simulations show that those algorithms greatly outperform the single-channel multicast algorithm. We also observe that MCM achieves better throughput and shorter delay while LCA can be realized in distributed manner. [ABSTRACT FROM AUTHOR]

The concept of a hybrid wireless-optical broadband access network (WOBAN) is a very attractive one. This is because it may be costly in several situations to run fiber to every home (or equivalent end-user premises) from the telecom central office (CO); also, providing wireless access from the CO to every end user may not be possible because of limited spectrum. Thus, running fiber as far as possible from the CO toward the end user and then having wireless access technologies take over may be an excellent compromise. How far should fiber penetrate before wireless takes over is an interesting engineering design and optimization problem, which we address in this paper. We propose and investigate the characteristics of an analytical model for network planning, namely optimum placements of base stations (BSs) and optical network units (ONUs) in a WOBAN (called the primal model, or PM). We develop several constraints to be satisfied: BS and ONU installation constraints, user assignment constraints, channel assignment constraints, capacity constraints, and signal-quality and interference constraints. To solve this PM with reasonable accuracy, we use "Lagrangean relaxation" to obtain the corresponding "Lagrangean dual" model. We solve this dual problem to obtain a lower bound (LB) of the primal problem. We also develop an algorithm (called the primal algorithm) to solve the PM to obtain an upper bound (UB). Via simulation, we compare this PM to a placement heuristic (called the cellular heuristic) and verify that the placement problem is quite sensitive to a set of chosen metrics. [ABSTRACT FROM AUTHOR]

The article discusses the design and trial deployments of indoor navigation with camera phones. The indoor navigation system associates locations with markers to offer a building orientation guide that relies on camera phones. A marker-based tracking suitability for continuous navigation in mobile phones has been examined through a controlled user study comparing system with a map without localization and with a global positioning system (GPS)-like real-time localization. Thus, the subjective experiences of users about ease of use and locate awareness have been evaluated.

This paper provides the economical tradeoffs for supporting multiple services over an OFDMA cellular network. These tradeoffs are related to two conflicting goals: (1) maximizing coverage so as to lower the system cost; and (2) maximizing the number of end users so as to maximize revenues. This problem is formulated in terms of coverage spectral efficiency, which directly determines the system capacity. We will analyze how the coverage geometry and the service requirements affect the coverage spectral efficiency, which determines the revenue generation. This paper also shows how the channel impairments (shadow fading, fast fading, and co-channel inference) affect the economics of the OFDMA system. [ABSTRACT FROM AUTHOR]

B3G (Beyond 3rd Generation) networks is the next step in the wireless world. It will enable the delivery of services to end-users, on different underlying wireless access networks and customised to users’ context. Furthermore, seamless mobility between networks and switch of devices will be handled in a transparent way. In this paper, a Context-Aware Network Equipment (CANE) is introduced, that is able to dynamically adapt multimedia services according to the users’ context. The term context includes the users’ device, the users’ preferences, the network conditions as well as the service provider adaptation policies. As a proof of concept, an implementation of a CANE is given for a 802.11 network use-case. An evaluation of the prototype as well as simulations of the proposed solution, both for an audio streaming service and a video streaming service, are presented. The results show that adapting multimedia services in case of network overload can enable to maintain an acceptable quality of service delivered to end-users and even to allow more users to enjoy the services, which will not be possible without the CANE. [ABSTRACT FROM AUTHOR]

WSNs typically comprise of sensing nodes with limited computational capability and onboard power. The sensed data in a WSN is transmitted from an individual node to a network sink in a multi-hop fashion. Since transmission costs are often several orders of magnitude larger than computational costs, the efficiency of the WSN can be improved by in-network data aggregation techniques. This is, however, problematic because the aggregation to be performed depends on the requirements of the end user / application, and is either unknown at the time of deployment or changes over time. Implementation of fixed aggregation algorithms limits the utility of the network. Software-based implementation of dynamic aggregation techniques offers the required flexibility but has significant processing overhead, especially when the size of the network increases. In this paper, we reduce the processing overhead by implementing dynamic data aggregation using reconfigurable cluster heads (RCHs) based on Field Programmable Gate Arrays (FPGAs). Such an implementation provides the necessary flexibility in data aggregation techniques demanded by real-time applications, while resulting in significant reduction in the query processing time and the overall power consumption in the network. The objective of the paper is to address the performance improvement in Wireless Sensor Networks (WSNs) through the use of reconfigurable cluster heads. Our results demonstrate that different data aggregation algorithms can be dynamically and efficiently implemented on the RCHs in run-time. The proposed approach is a crucial first-step towards the implementation of programmable WSNS. [ABSTRACT FROM AUTHOR]

Researches and development efforts in wireless networking and systems are progressing at an incredible rate. Among them, measurement and analysis of performance achieved at network layer and perceived by end users is an important task. In particular, recent advances concerning IEEE 802.11b-based networks seem to be focused on the measurement of key parameters at different protocol levels in a cross-layered fashion, because of their inherent vulnerability to in-channel interference. By adopting a cross-layer approach on a real network set-up operating in a suitable experimental testbed, packet loss against signal-to-interference ratio in IEEE 802.11b-based networks is hereinafter assessed. Results of several measurements aimed at establishing the sensitivity of IEEE 802.11b carrier sensing mechanisms to continuous interfering signals and evaluating the effects of triggered interference on packet transmission. [ABSTRACT FROM AUTHOR]

We consider the problem of allocating resources (time slots, frequency, power, etc.) at a base station to many competing flows, where each flow is intended for a different receiver. The channel conditions may be time-varying and different for different receivers. It is well-known that appropriately chosen queue-length based policies are throughput-optimal while other policies based on the estimation of channel statistics can be used to allocate resources fairly (such as proportional fairness) among competing users. In this paper, we show that a combination of queue-length-based scheduling at the base station and congestion control implemented either at the base station or at the end users can lead to fair resource allocation and queue-length stability. [ABSTRACT FROM AUTHOR]

Wireless networking is making major inroads into industry, but with it comes the inevitable issue of how to integrate such a 'game changing' technology with existing wired networks. End users who are still undecided over whether to take the plunge into the wireless networks route are looking for assurance in four principal areas standards, implementation, management and security. [ABSTRACT FROM AUTHOR]

User-centric networks (UCNs) are a recent architectural trend of self-organizing autonomic networks where the Internet end user cooperates by sharing network services and resources. UCNs are spontaneous and grassroots deployments of wireless architectures, ad hoc or infrastructured, often involving low-cost equipment. [ABSTRACT FROM PUBLISHER]

The convergence of emerging real-time multimedia services, the increasing coverage of high-speed wireless networks, and the evergrowing popularity of mobile devices are leading to an era of user-centric multimedia wireless services. In this scenario, heterogeneous wireless communications will coexist and ensure that the end user is always best connected. However, the quality of experience supported for highquality applications in multi-operator environments remains a significant challenge and is crucial for the success of wireless multimedia systems. This article proposes a quality of experience handover architecture for heterogeneous mobile wireless multimedia networks. The architecture extends the media independent handover/ IEEE 802.21 proposal with QoE-aware seamless mobility, video quality estimator, dynamic class of service mapping, and a set of content adaptation schemes. The proposed architecture always provides the best connection and considers the QoE needs of mobile clients and available wireless resources in IEEE 802.11e and IEEE 802.16e service classes. Simulation experiments were performed to show the impact and benefits of the proposed solution from the user?s perception, by using both objective and subjective QoE metrics. [ABSTRACT FROM PUBLISHER]