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In the Internet of Things (IoT) context, the massive proliferation of wireless devices implies dense networks that require cooperation for the multihop transmission of the sensor data to central units. The altruistic user behavior and the isolation of malicious users are fundamental requirements for the proper operation of any cooperative network. However, the introduction of new communication techniques that improve the cooperative performance (e.g., network coding) hinders the application of traditional schemes on malicious users detection, which are mainly based on packet overhearing. In this paper, we introduce a non-parametric statistical approach, based on the Kruskal-Wallis method, for the detection of user misbehavior in network coding scenarios. The proposed method is shown to effectively handle attacks in the network, even when malicious users adopt a smart probabilistic misbehavior. ; Grant numbers : This work has been supported by the research projects CellFive (TEC2014-60130-P) and AGAUR the Catalan Government (2014-SGR-1551).© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

The current and envisaged increase of cellular traffic poses new challenges to mobile network operators (MNO), who must densify their radio access networks (RAN) while maintaining low capital expenditure and operational expenditure to ensure long-term sustainability. In this context, this paper analyzes optimal clustering solutions based on device-to-device communications to mitigate partially or completely the need for MNOs to carry out extremely dense RAN deployments. Specifically, a low-complexity algorithm that enables the creation of spectral efficient clusters among users from different cells, denoted as enhanced clustering optimization for resources' efficiency is presented. Due to the imbalance between uplink and downlink traffic, a complementary algorithm, known as clustering algorithm for load balancing, is also proposed to create nonspectral efficient clusters when they result in a capacity increase. Finally, in order to alleviate the energy overconsumption suffered by cluster heads, the clustering energy efficient algorithm (CEEa) is also designed to manage the tradeoff between the capacity enhancement and the early battery drain of some users. Results show that the proposed algorithms increase the network capacity and outperform existing solutions, while, at the same time, CEEa is able to handle the cluster heads energy overconsumption. ; Grant numbers : This work has been funded by the CellFive (TEC2014-60130- P) projects as well as the AGAUR project the Catalan Government (2014 SGR 1551).© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

Energy harvesting brings a key solution to the increasing energy bill and environmental concerns but, at the same time, potential energy shortage may deteriorate the network availability. In this paper, we analyze the performance of off-grid small-cell base stations (scBS) with finite battery capacity and design a new power-availability-aware cell association based on periodical broadcast of the scBS battery level. Each mobile terminal (MT) targets its own set of available scBSs before association, i.e., the set of scBSs that can guarantee service provided 1) the scBS battery level; 2) the power required to satisfy a received power constraint at each MT, given the scBS-MT distance and the shadowing attenuation; and 3) the estimated power consumed to serve other MTs potentially associated to the same scBS, which is computed using stochastic geometry tools. Next, we develop for it a tractable performance analysis and derive closed-form expressions for the probability of power outage and the coverage probability. By dynamically adapting to the fluctuations of the base station battery and the MT received power requirement, the proposed cell association allows a more even distribution of the available energy in the network, brings robustness against harvesting impairment and thereby, significantly outperforms conventional strategies. ; Grant numbers : This work was supported in part by the Catalan Government 2014-SGR-1551, CellFive (TEC2014-60130-P).© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

In this paper we propose novel and more realistic analytical models for the determination of the peak demand under four power demand control scenarios. Each scenario considers a finite number of appliances installed in a residential area, with diverse power demands and different arrival rates of power requests. We develop recursive formulas for the efficient calculation of the peak demand under each scenario, which take into account the finite population of the appliances. Moreover, we associate each scenario with a proper real-time pricing process in order to derive the social welfare. The proposed analysis is validated through simulations. Moreover, the performance evaluation of the proposed formulas reveals that the absence of the assumption of finite number of appliances could lead to serious peak-demand over-estimations. ; Grant numbers : This work has been funded by the project of the Catalan Government 2014-SGR-1551.

The present paper studies fair sharing possibilities of stored renewable energy (RE) in densely populated areas among multiple mobile network operators (MNOs). The main objective is to enable MNOs, who already share their infrastructure in terms of a green network operation, to further reduce their power consumption by fairly sharing (i) the solar power harvested during daylight and (ii) the harvested energy that is stored in storage devices, e.g. batteries, during night hours. To this end, a bankruptcy game is designed so as to capture the energy sharing interactions among MNOs. Taking into consideration the energy deficits of each MNO for a studied period of time, Shapley Value (SV) is employed to fairly determine the amounts of energy to be allocated to each MNO. Focusing on night hours, it is shown that the proposed scheme provides all cooperative MNOs with long store-energy-based network operation during night in comparison to baseline schemes. Moreover, we display that the proposed scheme outperforms its counterparts in terms of needed grid support and allocation fairness among the cooperative MNOs for different MNO traffic patterns and volumes. ; Grant numbers : This work was supported by the Catalan Government (2014-SGR-1551), and CellFive (TEC2014-60130-P).© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

The anticipated explosion in the total data traffic load will impose to mobile network operators (MNOs) the necessity to densify their networks to provide coverage. At the same time, since MNOs plan their networks according to their high-peak traffic load, base station (BS) underutilization during the low traffic hours raises the issue of unnecessary power consumption and excessive cost. In this paper, we plan to study the energy and cost efficiency of a heterogeneous network (HetNet) that is a cooperation result of many MNOs. Each MNO is owner of a HetNet, composed of eNodeBs and small cells and they cooperate by sharing their infrastructure and by switching off a part of it. BS type and traffic load constitute switching off criteria and a roaming-cost-based user association scheme is used to roam traffic to neighboring BSs. We assess the cost alterations created by the possible MNO coalitions and we propose a bankruptcy game to allocate the obtained cost to the cooperative MNOs and to motivate them thus to maintain their sharing agreement instead of following a non-cooperative tactic. The bankruptcy game uses Shapley Value to portray each MNO's contribution to cost savings. The MNOs' satisfaction from their payoffs (i.e., the allocated cost) and the overall fairness of the method are evaluated. According to the extracted results, the proposed switching off scheme achieves significant improvement of energy efficiency for the studied network, while the proposed bankruptcy game achieves a balanced and satisfactory cost allocation for different MNO traffic loads. ; Grant numbers : This work has been funded by the Catalan Government (2014-SGR-1551), CellFive (TEC2014-60130-P).© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted ...

The fifth generation wireless networks are expected to offer high capacity and accommodate numerous over-the-top applications, relying on users' Internet connectivity, thus involving different stakeholders, that is, network service providers and over-the-top service providers. For the efficient management of over-the-top application flows, the implementation of service functions and their interconnection in service chains, namely network service chaining, should consider the over-the-top service providers' performance goals and user management strategies. However, in current wireless network deployments, the network service providers have full control of network service chaining. Considering that user satisfaction from the offered services is a common interest for both types of stakeholders, the over-the-top service providers need to participate in network service chaining, and apply QoS and user prioritization policies to network service chain resource management, which involves users connected at different network points, in a distributed manner. In this article, we describe 5G network management architectures and propose virtualization components that enable over-the-top service-provider- oriented network service. We also outline the arising issues for over-the-top service providers in network service chaining and introduce a distributed prioritization network service chain management scheme for over-the-top application flows, based on matching theory. The evaluation results indicate the performance gains in over-the-top service providers' service levels that stem from the proposed scheme, demonstrating the benefits of introducing prioritization in network service chain deployment. ; Grant numbers : This work has been funded by the Catalan Government (2014-SGR-1551), CellFive (TEC2014-60130-P).© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or ...

The rise of third-party content providers and the introduction of numerous applications has been driving the growth of mobile data traffic in the past few years. The applications' various Quality of Service (QoS) requirements as well as the use of multiple devices per user have increased the traffic heterogeneity, pressing the telecommunications industry to the deployment of dense Heterogeneous Networks (HetNets). At the same time, the content providers' rise has also led to the decrease of the Mobile Network Operators' (MNOs) revenues. Under these circumstances, the MNOs need to guarantee the users' Quality of Experience (QoE) requirements, while ensuring the sustainability of HetNet investments. To this end, we consider a HetNet deployment where MNOs offer a multitude of services with diverse pricing. We propose a heuristic, joint QoE-aware resource allocation and dynamic pricing algorithm with overall user satisfaction constraints to maximize the MNO profit, while providing high QoE. Simulation results show that the proposed algorithm can handle traffic heterogeneity by achieving substantial profit and QoE gains, compared to a state of the art algorithm. Moreover, we demonstrate the benefits of our dynamic pricing scheme and its applicability on other resource allocation algorithms. ; Grant numbers : This work has been funded by the Project CellFive (TEC2014- 60130- P), anb by the Catalan Government (2014-SGR-1551).© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

The reduction of energy consumption and the people's well-being, in smart buildings, rely on an accurate monitoring of the air quality. Thereby, herein an experimental platform is proposed to achieve this aim, which is inspired on an Internet of Things paradigm. The proposed approach is characterized by its scalability and its energy efficiency. Moreover, it is an end-to-end platform, as it permits to take measurements of the air quality, to store and process the information in a fusion center and to display in real-time the air quality in the Internet users' devices. ; Grant numbers : This work has been partially supported by the Generalitat de Catalunya (2014 SGR 1551) and the Spanish Government under project CellFive (TEC2014-60130-P).© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

The latest impressive technological advancements in the telecommunications domain have entailed the involvement of new network operators and over-the-top (OTT) providers that offer their services over the existing networks. This entry of new stakeholders has changed the Internet dynamics and triggered a long-standing conversation on whether different types of data in the network should be prioritized, also known as the network neutrality debate. On the one hand, OTT providers benefit from the current neutral Internet policy of not discriminating against any application or content in order to transfer their data for free, whereas network providers would like to seize the business opportunity and create revenues by supporting the prioritized delivery of data. In this article, we want to shed light on the emerging Internet ecosystem and the conflicting interests of its stakeholders. To that end, we first identify the different Internet players and describe their interrelationships. Furthermore, in an effort to offer a new perspective on the network neutrality debate, we propose two novel econometric models that employ recent financial data to capture the relationship between the OTT revenues and the financial gains and investments of the telecommunication operators. Our empirical results provide tangible answers to fundamental questions that had not been answered before, showcasing that OTT and telecommunication providers have aligned interests and their collaboration could be beneficial to both parties. ; Grant numbers : This work has been supported by the Catalan Government (2014-SGR-1551) and CellFive (TEC2014-60130-P).© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

The rise of Over The Top (OTT) content providers and the introduction of numerous applications has been driving the growth of mobile data traffic in the past few years. The applications' various Quality of Service (QoS) requirements as well as the use of multiple devices per user have increased the traffic heterogeneity, pressing the telecommunications industry to the deployment of 5G networks in 2020. At the same time, the rise of OTT providers has also led to the decrease of the Mobile Network Operators' (MNOs) revenues. Under these circumstances, the MNOs need to guarantee the users' Quality of Experience (QoE) requirements, while ensuring the sustainability of a 5G investment. To this end, we consider a 5G Heterogeneous Network (HetNet) deployment where MNOs use a QoE-based charging scheme. We propose a heuristic, QoE-aware user association algorithm to maximize the MNO profit, while providing high QoE. Simulation results show that the proposed algorithm can handle traffic heterogeneity by achieving substantial profit and QoE gains, compared to a baseline SINR-based scheme. ; Grant numbers : This work has been funded by the Project CellFive (TEC2014- 60130-P), and the Catalan Government (2014-SGR-1551).© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

Wireless network virtualization enables efficient network sharing in Long Term Evolution Advanced (LTE-A) networks. For the accommodation of ever-increasing user demands, Mobile Virtual Network Operators (MVNOs) can lease and operate virtual resources in network infrastructure that belongs to Mobile Network Operators (MNOs). The coexistence of multiple MVNOs that serve users with different Quality of Service (QoS) requirements and spatial distribution in an LTE-A cell further complicates the arising resource allocation problem. Moreover, the MVNOs aim to satisfy the QoS demands for the maximum possible number of users with the minimum possible cost. This multifaceted context renders centralized optimization approaches for virtual resource allocation in shared LTE-A networks unsuitable. As an alternative, the framework of matching theory, thanks to its distributed nature, can achieve a proper allocation through a stable matching between resources and MVNOs. In this context, we introduce a matching-theoretic formulation for the virtual resource allocation problem and propose a distributed algorithm that properly matches the MVNOs with the available resources. Our simulation results show that the proposed algorithm reaches a stable matching that satisfies the QoS demands for more users in comparison with other approaches. ; Grant numbers : This work has been funded by the Research Project CellFive (TEC2014-60130-P), AGAUR the Catalan Government (2014-SGR-1551).© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

Smart Grid (SG) is considered as the future of the electrical power distribution system, where Advanced Metering Infrastructure (AMI) will let utilities to acquire and analyze the consumption data and access and control several home appliances for power balancing purposes through special devices, known as Smart Meters (SMs). Long Term Evolution (LTE) appears as a promising solution to handle the SMs traffic due to its high bandwidth and flexibility. However, given that SMs need to periodically send measurements to the eNodeB (eNB), the network uplink could be a potential bottleneck, thus affecting the users running real-time applications, such as voice calls. To overcome this problem, in this paper, we present a scheduling policy that jointly considers the channel quality, the traffic prioritization and the AMI Packet Delay Budget (PDB) in order to provide the SMs with the required resources and reduce the impact on the real-time traffic. Extensive simulation experiments have been carried out, indicating the smooth coexistence between the SMs and the voice users, since the proposed scheduler achieves higher percentage of served users compared to widely employed schedulers. ; Grant number : This work has been partially supported by the Catalan Government 2014-SGR-1551.© 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

We study the performance of Machine-to-Machine (M2M) communications in Long Term Evolution Advanced (LTE-A) networks. The proposed analysis is applied to the random access procedure within LTE-A for the calculation of the average overall delay, by considering multiple classes of M2M devices with diverse Quality-of-Service (QoS) requirements. The QoS differentiation is expressed through different Access Class Barring (ACB) parameters and backoff times for the various QoS classes. For the packet arrival process of M2M devices we consider an ON-OFF arrival process, which is a realistic approach, especially for M2M communications in Smart Grid environments. Furthermore, the proposed analysis is suitable for smart grid communication networks, where multiple M2M gateways are installed in different points of the network. The comparison of analytical results with simulations reveals the high accuracy of the proposed analysis. ; Grant numbers : This work has been partially funded by the project AGAUR by the Catalan Government 2014-SGR-1551 and by the project CellFive (TEC2014-60130-P).© 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

In this paper, we demonstrate an analytical model for computing the end-to-end packet delay of a converged optical/wireless 60 GHz Radio-over-Fiber (RoF) network operating under the medium-transparent MAC (MT-MAC) protocol. For the calculation of the cycle times, this model considers the protocol time consumed for contention and data exchange over both optical and wireless media, a feature of the MT-MAC that effectively enables it to provide direct and seamless interaction between the RoF Central Office and the end users. This new analytical model enables us to conduct an extensive delay performance analysis of the various performance aspects of hybrid RoF networks operating under the fixed service paradigm, such as various optical capacity availability scenarios, varying load conditions, optical network ranges, transmission window lengths, and data packet sizes. The derived theoretical results present an excellent match with the respective simulation findings, providing sub millisecond latency values for a plethora of network conditions, confirming that the MT-MAC scheme can effectively be incorporated into the upcoming mm-wave 5G era. ; Grant numbers : This work was supported by the research projects the Catalan Government (2014-SGR-1551), CellFive (TEC2014-60130-P).© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.