Lluís Gutierrez

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Ethernet-based passive optical networks (EPON) are being considered as the best candidates for the next generation broadband access networks. Several algorithms for dynamic bandwidth allocation in EPON have been proposed, as this is an open issue that was left out of the scope of the standard IEEE 802.3ah. Very few of those works address the possibilities(More)
The Next Generation Access Networks (NGAN) are the new step forward to deliver broadband services and to facilitate the integration of different technologies. The real challenge faced by 10GEPON new standard IEEE 803.3av is to upgrade the channel capacity for both upstream and downstream channels gracefully, while maintaining the logical layer intact(More)
Even if Passive Optical Networks (PONs) have proven to be more energy-efficient that other access solutions, energy consumption minimization is becoming an important research target also in PON. In particular, to sustain the increased bandwidth demand of emerging applications in the access section of the network, new hybrid PON solutions employing WDM/TDM(More)
The access network infrastructure plays an important role in the overall performance of the network, next generation access networks (NGA) must be able to access diverse services, and should incorporate adequate architectures that include mechanisms for the integration of different technologies. New optical access technologies trends are: WDM, 10 Gb/s, and(More)
may communicate in a multihop fashion, forming mesh networks. To maintain cost and resource efficiency, we propose the introduction of Quality of Service (QoS) proxies at the border between different link technologies. These entities handle QoS requirements and aid to the support of mobility. The architecture requires no modification of the Medium Access(More)
CANDLE (Cooperative And Network Distributed Learning Environment) is a new European project supported by European Telecommunications Schools members of EUNICE, and others partners The objective of this project is to use the Internet to improve the quality and reduce the cost of ICT teaching in Europe by using web and multimedia technology, and to enable(More)
Random Multi-access Protocols has been used as the MAC protocol over Multi-access channels. They are specially recommended when there are a large population of users with low and bursty traffic as for example it will be in HFC (Hybrid Fiber-Coax) networks with multimedia services, we should be sure that the access to the network copes with the QoS. each(More)
This paper presents a new dual mode nonlinear model predictive controller (NMPC) that is based on the combination of the finite horizon NMPC with the infinite horizon predictive controller (IHMPC). The resulting nonlinear controller is shown to be stable when the IHMPC is globally stabilizing. The main advantage of the proposed controller in comparison to(More)