Academic Positions

  • Present 2014

    Assistant Professor

    Federal University of Ceará, Department of Computing

  • 2014 2011

    Senior Researcher

    Federal University of Ceará, Department of Teleinformatics Engineering

Education & Training

  • Ph.D. 2011

    Ph.D. in Signal Theory and Communications

    Universitat Politècnica de Catalunya (UPC/BarcelonaTech), Departament de Teoria del Senyal i Comunicacions

  • M.Sc.2004

    Masters in Electrical Engineering

    Federal University of Ceará (UFC), Department of Electrical Engineering

  • B.Sc.2001

    Graduation in Electrical Engineering

    Federal University of Ceará (UFC), Department of Electrical Engineering

Honors, Awards and Grants

  • 2011-2014
    PostDoctoral Scholarship Grant
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    National Council of Scientific and Technological Development (CNPq) / State of Ceará's Foundation for the Support of Scientific and Technological Development (FUNCAP)
  • 2007-2011
    Ph.D. Scholarship Grant
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    Coordination for the Improvement of Superior Level Personnel (CAPES)
  • 2002-2004
    Masters Scholarship Grant
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    Coordination for the Improvement of Superior Level Personnel (CAPES)
  • 2000
    Motorola PCT Grant
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    Technological Capacitation Program (PCT) by Motorola / Eldorado Institute
  • 1998-1999
    Scientific Initiation Scholarship Grant
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    National Council of Scientific and Technological Development (CNPq) / Federal University of Ceará (UFC)

Research Groups

João César M. Mota

Professor (GTEL)

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Rodrigo P. Cavalcanti

Director/Professor (GTEL)

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Emanuel B. Rodrigues

Professor (GTEL/GREat)

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Rossana M. de C. Andrade

Director/Professor (GREat)

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José Neuman de Souza

Professor (GREat)

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Miguel F. de Castro

Professor (GREat)

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Danielo G. Gomes

Professor (GREat)

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Fernando A. M. Trinta

Professor (GREat)

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Windson V. de Carvalho

Professor (GREat)

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Lincoln S. Rocha

Professor (GREat)

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Atslands R. da Rocha

Professor (GREat)

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Ligia Maria Carvalho Sousa

Professor (GTEL)

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Elvis Stancanelli

Professor (GTEL)

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Rafael M. Lima

Professor (GTEL)

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Carlos Estevão Rolim

Professor (GTEL)

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Tarcisio F. Maciel

Professor (GTEL)

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Yuri Carvalho B. Silva

Professor (GTEL)

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André L. Férrer

Professor (GTEL)

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Walter F. Cruz

Professor (GTEL)

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Charles C. Cavalcante

Professor (GTEL)

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Wireless Telecom Research Group (GTEL)

GTEL is associated with the Department of Teleinformatics Engineering (DETI), located at UFC’s Campus do Pici. The group was created in June 2000 with a mission of developing wireless communications technology through academic research performed by DETI’s Professors, undergraduate, Master and Doctor of Science students and external consultants. The GTEL’s objective is to offer research, consulting and technical cooperation services in wireless telecommunications technologies through independent research and partnerships with the academia and the industry. Web site: www.gtel.ufc.br.

Group of Computer Networks, Software Engineering and Systems (GREat)

GREat is composed of professors and students (graduate and undergraduate) of the Federal University of Ceará (UFC) and other Institutions. GREat was founded in 2002 and its main research areas are Computer Networks (management, security, sensor networks, and so on), Software Engineering (e.g., reuse, ubiquitous computing), and Systems (for example, multimedia, design, education). Web site: www.great.ufc.br.

Research Projects

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    UFC.40: Quality of Service Provision and Control for 5th Generation Wireless Systems

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    UFC.33: Radio Resource Management for QoS Control and Device-to-Device Communications in Next Generation Wireless Systems

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    UFC.30: Radio Resource Management for Quality of Service Provision and Device-to-Device Communications

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    NEWCOM++: Network of Excellence in Wireless Communications

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    UFC.18: Radio Resource Allocation for OFDMA-Based Multi-Cell and Multi-User Wireless Systems

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    UFC.17: Radio Resource Management for Emerging Services in Evolved UMTS Networks

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    UFC.10: Advanced and Global Radio Resource Management for Multi-Service and Multi-Access Networks

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    Admission Control for Streaming Services over HSDPA

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    UFC.08: Extended Research in Radio Resource Management for the Efficient Provision of 3G Services

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    UFC.07: Radio Resource Management for the Efficient Provision of 3G Services

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    UFC.01: Advanced Algorithms of Spatial-Temporal Processing for the Evolution of the EDGE System Towards the Third Generation

Filter by type:

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Maximization of User Satisfaction in OFDMA Systems Using Utility-Based Resource Allocation
Emanuel B. Rodrigues, Francisco R. M. Lima, Tarcisio F. Maciel and Francisco R. P. Cavalcanti
Journal Paper Wireless Communications and Mobile Computing, Volume 1, September 2014, Pages 1-17

Abstract

In order to keep and/or expand its share of the wireless communication market and decrease churn, it is important for network operators to keep their users (clients) satisfied. The problem to be solved is how to increase the number of satisfied non-real time (NRT) and real time (RT) users in the downlink of the radio access network of an orthogonal frequency division multiple access system. In this context, the present work proposes a method to solve the referred problem using a unified radio resource allocation (RRA) framework based on utility theory. This unified RRA framework is particularized into two RRA policies that use sigmoidal utility functions based on throughput or delay and are suitable for NRT and RT services, respectively. It is demonstrated by means of system-level simulations that a step-shaped sigmoidal utility function combined with a channel-aware opportunistic scheduling criterion is effective toward the objective of user satisfaction maximization.

Rate Adaptive Resource Allocation and Utility-Based Packet Scheduling in Multicarrier Systems
Emanuel B. Rodrigues, Ferran Casadevall
Journal Paper Majlesi Journal of Electrical Engineering, Volume 5, 2011, Pages 38-49

Abstract

Control of the Trade-off Between Resource Efficiency and User Fairness in Wireless Networks Using Utility-Based Adaptive Resource Allocation
Emanuel B. Rodrigues, Ferran Casadevall
Journal Paper IEEE Communications Magazine, Volume 49, Issue 9, 2011, Pages 90-98

Abstract

This work addresses the fundamental problem of the trade-off between resource efficiency and user fairness in wireless networks that use opportunistic radio resource allocation. The concept of managing the trade-off by controlling the system fairness index is applied. In order to do that, two adaptive utility-based resource allocation frameworks consisting of subcarrier assignment and power allocation algorithms are proposed. These frameworks are named utility-based alpha-rule and beta-rule, and are suitable for non-real-time and real-time services, respectively. Not only can both frameworks be designed to work as wellknown classic policies found in the literature, but also as adaptive policies, which are able to meet a desired system fairness target. System level simulations show that the proposed frameworks are powerful tools to the network operator, since they can decide in which trade-off point of the efficiency-fairness plane they want to operate the system.

QoS-driven Adaptive Congestion Control for Voice over IP in Multiservice Wireless Cellular Networks
Emanuel B. Rodrigues, Francisco R. P. Cavalcanti, Stefan Wänstedt
Journal Paper IEEE Communications Magazine, Volume 46, Issue 1, 2008, Pages 100-107

Abstract

This work establishes a QoS-driven adaptive congestion control framework that provides QoS guarantees to VoIP service flows in mixed traffic scenarios for wireless cellular networks. The framework is composed of three radio resource management algorithms: admission control, packet scheduling, and load control. The proposed framework is scalable to several services and can be applied in any current or future packet-switched wireless system. By means of dynamic system-level simulations carried out in a specific case study where VoIP and Web service flows compete for shared access in an HSDPA wireless network, the proposed framework is able to increase the overall system capacity twofold depending on the traffic mix, while keeping the system operating optimally in its target QoS profile.

Resource Allocation for Improved User Satisfaction with Applications to LTE

Francisco R. M. Lima, Emanuel B. Rodrigues, Tarcisio F. Maciel, Mats Nordberg
Book Chapter Springer New York, 2013, Pages 63-104 | ISBN-13: 978-1-4614-8056-3
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Book: Resource Allocation and MIMO for 4G and Beyond

Abstract

Cellular networks have experienced a strong development in the past decades and the technology evolution to meet the continued steep increase of mobile traffic expected for the next years is an important challenge. In this context, cellular operators have as objective to increase the number of satisfied users in the system whereas users or subscribers aim at having fulfilled their expected quality of service. In order to increase the number of satisfied users in the system we identify radio resource allocation as a key functionality. Radio resource allocation is responsible for managing and distributing the available scarce resources of the radio interface to the active connections. In this chapter, we present radio resource allocation strategies with multiple antennas at the transmitter and/or receivers to increase the number of satisfied users in cellular networks based on two approaches: heuristic and utility-based strategies. While the heuristic design provides simple and quick solutions to the radio resource allocation problems, the utility-based approach is a flexible and general tool for radio resource allocation design. Simulation results show that the proposed algorithms following these design guidelines are able to achieve high number of satisfied users in modern networks..

Capacity, Fairness, and QoS Trade-Offs in Wireless Networks with Applications to LTE

Emanuel B. Rodrigues, Francisco R. M. Lima, Ferran Casadevall, Francisco R. P. Cavalcanti
Book Chapter Springer New York, 2013, Pages 157-211 | ISBN-13: 978-1-4614-8056-3
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Book: Resource Allocation and MIMO for 4G and Beyond

Abstract

Wireless mobile network optimization is a complex task that consists in achieving different design objectives such as spectral efficiency, energy efficiency, fairness, and quality of service. Radio resource allocation is responsible for managing the available resources in the radio access interface and, therefore, is an important tool for optimizing networks and achieving the designed objectives mentioned previously. However, in general all these network design objectives cannot be achieved at the same time by resource allocation strategies. In fact, different resource allocation strategies can be designed to maximize one objective in detriment of the other as well as to balance the objectives. In this chapter we deal with important trade-offs between contradicting objectives in modern wireless mobile networks: capacity versus fairness and capacity versus satisfaction. We present resource allocation strategies that can achieve static and adaptive performances when the previously mentioned trade-offs are considered. In order to design the resource allocation strategies we consider heuristics and utility-based solutions. System-level simulations show that the proposed techniques are powerful tools to the network operator, since they can decide in which trade-off point of the capacity-fairness or capacity-satisfaction planes they want to operate the system.

On the Influence of Packet Scheduling on the Trade-Off between System Spectral Efficiency and User Fairness in OFDMA-Based Networks

Emanuel B. Rodrigues, Michael L. Walker, Ferran Casadevall
Book Chapter Springer Berlin Heidelberg, 2009, Pages 128-137 | ISBN-13: 978-3-642-03699-6
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Book: The Internet of the Future

Abstract

System spectral efficiency and user fairness are crucial aspects for resource allocation in multi-user OFDM-based cellular networks. This work intends to investigate the influence of the performance of packet scheduling algorithms on the trade-off between these two objectives in scenarios with non real-time and real-time services. By means of system-level simulations, we were able to create a didactic map of the relation between these two aspects and propose ways to exploit this trade-off efficiently.

Congestion Control for Wireless Cellular Systems with Applications to UMTS

Emanuel B. Rodrigues, Francisco R. P. Cavalcanti, Stefan Wänstedt
Book Chapter Springer US, 2009, Pages 141-185 | ISBN-13: 978-1-4419-0154-5
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Book: Optimizing Wireless Communication Systems

Abstract

A wireless cellular network operates normally when the offered traffic load stays around or below a target point efined in the network planning phase. The network is able to work in an optimized way thanks to the operation of RRM algorithms, which meet the contracted QoS requirements for the majority of users causing few service outages, and maintain the planned coverage. However, there can be a mismatch between the network capacity and the users’ current demands due to system dynamics, which can cause network overload and service outage (congestion situations). Network congestion can be caused by some factors, such as voice and data traffic dynamics, network utilization pattern during specific periods of the day (busy hours), random behavior of the external interference, subscribers’ profiles (commercial and residential areas) and their call distributions, different mobility profiles, and geographical location of mobile terminals. These factors can cause variations on the QoS experienced by the users and the cell load. In order to guarantee the resources necessary for the provision of real-time (RT) services despite load/QoS fluctuations, a congestion control (CC) technique must be employed.

Evaluation of Fixed Thresholds for Allocation and Management of Dedicated Channels Transmission Power in WCDMA Networks

Carlos H. M. Lima, Emanuel B. Rodrigues, Vicente A. Sousa, Francisco R. P. Cavalcanti
Book Chapter Springer Berlin Heidelberg, 2004, Pages 1122-1127 | ISBN-13: 978-3-540-22571-3
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Book: Telecommunications and Networking - ICT2004

Abstract

The major goal of this contribution is to evaluate strategies for allocation and management of the Dedicated Traffic Channels (DCH) transmission power in a WCDMA radio access network. The power allocation and control solution is tested aiming power consumption saving while the system QoS requirements are kept in acceptable levels. We focus on multi-cellular dynamic system-level simulations of the WCDMA radio access network in the forward link for the conversational service class. From these investigations we address the feasibility of our solution.

Utility-Based Resource Allocation with Spatial Multiplexing for Real Time Services in Multi-User OFDM Systems

Emanuel B. Rodrigues, Francisco H. C. Neto, Tarcisio F. Maciel, Francisco R. M. Lima, Francisco R. P. Cavalcanti
Conference Paper IEEE 79th Vehicular Technology Conference (VTC2014-Spring), May 2014, Seoul, Pages 1-5.

Abstract

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.

Fairness-Based Dynamic Sub-carrier Assignment for Real Time Services in OFDMA Networks

Emanuel B. Rodrigues, Ferran Casadevall
Conference Paper 20th European Wireless Conference, 2014, Barcelona, Pages 1-6

Abstract

Utility-Based Scheduling and Fixed Switching Beamforming for User Satisfaction Improvement in OFDMA Systems

Emanuel B. Rodrigues, Francisco H. C. Neto, Tarcisio F. Maciel, Francisco R. M. Lima, Francisco R. P. Cavalcanti
Conference Paper 20th European Wireless Conference, 2014, Barcelona, Pages 1-6

Abstract

Evaluation of Utility-Based Adaptive Resource and Power Allocation for Real Time Services in OFDMA Systems

Yuri V. L. Melo, Emanuel B. Rodrigues, Francisco R. M. Lima, Tarcisio F. Maciel, Francisco R. P. Cavalcanti
Conference Paper International Telecommunications Symposium (ITS), 2014, São Paulo, Pages 1-5

Abstract

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).

Optimal Distributed Frequency Planning for OFDMA Femtocell Networks

Emanuel B. Rodrigues, Ferran Casadevall
Conference Paper IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC), 2013, London, Pages 2914-2918

Femtocell networks have gained momentum due to their important benefits, such as improved indoor coverage, higher areal spectral efficiency, enhanced signal quality, among others. Those benefits are only achievable if adequate deployment decisions and efficient resource allocation techniques are able to assure the seamless co-existence among Femtocell Access Points (FAPs) within the femtocell tier and between FAPs and macrocell users. In this work, we study the frequency planning problem on the femtocell tier deployed on a closed access mode and using a dedicated spectrum. A novel radio resource allocation technique that performs a mid/long-term frequency planning for the FAPs in the femtocell tier is proposed. It is concluded in this paper that the Dynamic Frequency Planning (DFP) algorithm based on the Branch and Bound technique is able to find the optimal frequency planning according to any desired criterion and that the proposed algorithm is suitable for implementation in a distributed 4G femtocell network regarding signaling overhead and latency aspects.

Rate Adaptive Resource Allocation with Fairness Control for OFDMA Networks

Conference Paper 18th European Wireless Conference, 2012, Poznan, Pages 1-8

Method and Apparatus for Resource Allocation Satisfying Multiple Performance Constraints

Francisco R. M. Lima, Tarcisio F. Maciel, Walter C. F. Júnior, Francisco R. P. Cavalcanti, Níbia S. Bezerra, Emanuel B. Rodrigues
Patent WIPO - World Intellectual Property Organization, 2013 | Patent number WO2014077769A1

Abstract

A low-complexity, efficient Radio Resource Allocation method performed by a base station of a wireless communication network allocates a first plurality of frequency resources among a second plurality of requesting mobile terminals. Each mobile terminal employs a service such that two or more services are represented in the second plurality. The RRA method satisfies all of an exclusivity constraint that each frequency resource is allocated to only one mobile terminal, an adjacency constraint that all frequency resources allocated to any given mobile terminal are contiguous in a frequency domain, and a minimum service requirement constraint that a predetermined number of the mobile terminals employing each service be granted a required data rate. The RRA method comprises two phases: Unconstrained Maximization and Reallocation. In the Unconstrained Maximization phase, frequency resources are iteratively allocated to mobile terminals in an opportunistic way, obeying the exclusivity and adjacency constraints but without concern for the minimum service requirement constraint; the resulting allocation is tested for fulfillment of the minimum service requirement constraint; and one or more mobile terminals are removed from the allocation based on the minimum service requirement constraint test. In the Reallocation phase, frequency resources from one or more mobile terminals that have their required data rate fulfilled are reallocated to one or more mobile terminals that do not have their required data rate fulfilled.

Currrent Teaching

  • Present

    Computer Science Undergraduate Course / Federal University of Ceará

    Data Transmission (CK0170)

    Advanced Topics in Computer Networks (CK0158)

  • Present

    Computer Science Postgraduate Program / Federal University of Ceará

    Wireless and Mobile Networks (CKP8222)

Teaching History

  • Present 2014.1

    Computer Science Undergraduate Course / Federal University of Ceará

    Computer Networks (CK0061)

    Data Transmission (CK0170)

    High-Speed Networks (CK0162)

    Computer Programming for Enginners (CK0174 / CK0179)

    Numerical Calculus (CK0012)

  • Present 2015.1

    Computer Science Postgraduate Program / Federal University of Ceará

    High-Speed Networks (CKP7566)

At My Office

Av. Mister Hull, s/n

Federal University of Ceará (UFC)

Department of Computing (DC)

Campus do Pici - Building 910 (1st floor)

Zip code: 60440-900

Fortaleza/CE, Brazil

At GTEL Lab

Av. Mister Hull, s/n

Campus do Pici - Building 722

PO Box: 6005

Zip code: 60455-760

Fortaleza/CE, Brazil

At GREat Lab

Av. Mister Hull, s/n

Campus do Pici - Building 942-A

Zip code: 60455-760

Fortaleza/CE, Brazil