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With the evolution of communication technologies, new applications have emerged aiming to improve the processes of information exchange and innovation, at the forefront of this evolution is the fifth generation of mobile networks (5G), which should provide the infrastructure for these new applications that have high capacity, reliability, energy efficiency and latency requirements. In this context, there are a number of changes that must be made to the network infrastructure, including Core Network (CN) and Radio AccessNetwork (RAN) to support these new applications. In this work we demonstrate the implementation of Quality of Service (QoS) control through the Software Defined Network (SDN) paradigm in an abstract (CN) infrastructure, with the objective of investigating the benefits of using SDN for new scenarios and challenges for 5G network. Experiments carried out with the Ryu SDN controller, demonstrated that the application of QoS through the SDN can bring benefits to the performance of these new applications.

Given the advance of the Smart Grid technology, the electrical grid is now in a process of transformation never seen in history. This new grid model allows customers and providers to generate and manage electrical power efficiently. To support such transformation, a key element of the model is the communication network responsible for delivering measurement data from sensors on the grid to the applications that analyze and adapt distribution according to demands. This work proposes and evaluates a system architecture that copes with reliability and latency demands that are of much importance for a successful Smart Grid deployment, also considering the internal design of distributed applications in the context of Smart Grids. The architecture adopts a Mobile Edge Computing based infrastructure that is suitable for 4G and 5G mobile cellular networks. Experiments made on NS-3 shows that the proposed system architecture is capable of handling a realistic number of smart meters while providing low latency and network reliability, supporting many use cases of a Smart Grid deployment.

This paper analyzes the performance of Adaptive Power Allocation (APA) based on (multi-level) water filling as a novel extension of a utility-based Radio Resource Allocation (RRA) framework designed for Real Time (RT) service provision in Orthogonal Frequency Division Multiple Access (OFDMA)-based systems. We evaluate capacity, satisfaction and fairness improvements that originate from exploiting the high degree of flexibility of RRA in the context of OFDMA systems and particularly, concentrate on optimal power allocation combined with utility-based scheduling. Results show that Delay-based Satisfaction Maximization (DSM) presents the best performance to maximize user satisfaction in comparison with classical algorithms and conclude also that benefit of APA is marginal compared to Equal Power Allocation (EPA).

In order to expand its market share and decrease churn, cellular network operators want to achieve the maximum possible number of satisfied clients. In this paper, we propose to solve the problem of user satisfaction maximization using an utility- based dynamic resource assignment algorithm that uses a sigmoidal utility function combined with either Orthogonal Random Beamforming (ORB) or Fixed Switching Beamforming (FSB). System-level evaluations of the downlink of an Orthogonal Frequency Division Multiple Access (OFDMA) system with real-time services demonstrate that there is an optimal number of spatial beams to be used by ORB and FSB, that FSB outperforms ORB with lower complexity, and also that the proposed joint resource assignment and beamforming outperforms other classical techniques found in the literature.

In this paper a study on different Radio Resource Management (RRM) methods employed in a multi-carrier cellular system is presented. This work focuses on the rate-adaptive resource allocation (sub-carriers and power), as well as the utilitybased packet scheduling algorithms. The objective of the paper is to study the trade-off between system spectral efficiency and fairness among the users when the considered algorithms are used.

Spectral efficiency, fairness and user satisfaction are crucial aspects for resource allocation in multi-user Orthog- onal Frequency Division Multiplexing (OFDM)-based cellular networks. Classical Radio Resource Allocation (RRA) strategies, such as Max-Rate (MR), Proportional Fairness (PF) and Max- Min Fairness (MMF), show different performances regarding the three aforementioned aspects. In this work, we present an adap- tive RRA framework that joins the criteria of the three classical strategies in a unified manner and can be dynamically configured according to the cellular operator's objectives. We exemplify the flexible use of this general framework by proposing two adaptive RRA algorithms that provide strict fairness among users and maximizes the users' satisfaction, respectively. Simulation results show that the two proposed algorithms can efficiently achieve their respective objectives by means of the adaptation of the general RRA framework.

By means of dynamic system level simulations, this work evaluates the performance of two proposed Load Control algorithms that are capable of guaranteeing the QoS of the VoIP service in a mixed traffic scenario in the HSDPA network. It was shown that the LC algorithms are efficient at maximizing the VoIP satisfaction, and therefore the overall system capacity, by means of a soft and controlled degradation of the QoS of the WWW service.

By means of dynamic system-level simulations, this work evaluates whether the studied Packet Scheduling (PS) algorithms are capable of guaranteeing the Quality of Service (QoS) of the Voice over IP (VoIP) on a scenario where the VoIP and web browsing services will compete for the same resources. Two sets of algorithms were considered: QoS-differentiated and non-QoS-differentiated algorithms. It can be concluded that, in general, the PS algorithms able to perform QoS differentiation presented better performance in terms of system capacity and QoS compared to those non-QoS-differentiated algorithms. Among the former category, those that take into consideration delay requirements of the VoIP service presented the best overall capacity for all traffic mixes.

This article introduces a software development framework, which amasses object-oriented programming (OOP) concepts and designed procedures, intended to systematize the implementation of link-level simulation tools. This development framework is fully implemented in C++ programming language providing modularity and reusability (improving the coding activity). This framework then constitutes remarkable tool for quickly creating link-level applications. Aiming to evaluate the applicability of this software structure, the conversational service class transmitting at 12.2 kbps and over the Wideband CDMA (WCDMA) Downlink (DL) dedicated channel (DCH) is addressed as a case-study and therefore potential benefits of utilizing such development library are identified. It is shown that the development framework provides flexibility for the software development of link-level simulators remarkably reducing the design, programming and testing stages.

By means of dynamic system-level simulations, this work evaluates whether the studied Packet Scheduling (PS) algorithms are capable of guaranteeing the quality of service (QoS) of the voice over IP (VoIP) on a scenario where the VoIP and Web browsing services will compete for the same resources and there is a maximum allowed end-to-end delay for VoIP packets. Two sets of algorithms were considered: QoS-differentiated and non-QoS-differentiated algorithms. It was verified the system capacity gains when the VoIP delay budget is increased. Regarding the PS performance, those algorithms able to perform QoS differentiation presented better performance in terms of system capacity and QoS compared to those non-QoS-differentiated algorithms. Among the former category, those that take into consideration delay requirements of the VoIP service presented the best overall capacity for all traffic mixes and delay budgets.

The growth in the number of voice over IP (VoIP) users on the Internet makes it the service with the highest interest to be provided by cellular operators. On the other hand, it demands very strict QoS control, which becomes even more complicated in wireless networks, because packets can be lost due to radio link transmission errors, as well as network congestion. Within this paradigm, scheduling strategies appear as the most suitable solution to cope with QoS guarantees under high loads, where the resources should be carefully distributed among the users in order to fulfill their QoS requirements. This work comprises the proposal and evaluation of some scheduling algorithms aiming to improve system capacity and QoS guarantees for speech users in HSDPA. The results show that the scheduling algorithms that mix fairness with channel information to get improvements of the multi-user diversity provide the best performance.

The paper specifies congestion resolution (action) and recovery (reaction) procedures within a load control (LC) functionality in the WCDMA downlink air interface. By means of dynamic system level simulations, it is verified that, in soft overload situations, it is advantageous to give lower priority to those radio links that have worse channel quality, so that the system can return to its stable state in a gradual and controlled manner.

In this contribution we evaluate the utilization of fixed thresholds for allocation and management of downlink dedicated channels (DCH) transmission power in WCDMA mixed service scenarios. We have made use of system-level dynamic simulation approach. We assess modified versions of the call admission control (CAC) and the power control (PC) algorithms. The system performance is evaluated taking into consideration the quality of service (QoS) experienced by connected users and the utilization of available power resources.

The paper proposes and evaluates an efficient power and code based admission control algorithm that is capable of fulfilling the QoS demands of the streaming users mapped on the HS-DSCH (high speed downlink shared channel). A mixed traffic scenario, where streaming users have to coexist with speech users mapped on dedicated channels (DCH) and Web browsing users mapped on HS-DSCH, is considered. By means of system level dynamic simulations, it is concluded that our proposed algorithm is able to improve the satisfaction of streaming users with minor impact on the QoS of speech and Web browsing users.

The major purpose of this contribution is to analyze an hierarchical cell structure with a hot spot embedded in a WCDMA macrocellular system. Particular attention is paid to the impact of the introduction of smart antennas in this context. A system-level simulation approach is employed where we consider two main solutions to deal with the hot spot traffic: the placement of a microcell antenna or the adoption of smart antenna technology at the macrocell. Relative gains in signal-to-interference ratio (SIR) are then evaluated. Distinct scenarios are defined based on the proportion of users of different service classes. An evaluation of which solution is better suited for each scenario is then carried out.