Browsing by Author "Cerutti, Isabella, 1973-"
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Item An automatic repeat request protocol for cooperative slotted radio networks(The University of Texas at Dallas, 2013-06-18) Cerutti, Isabella, 1973-; Fumagalli, Andrea; Gupta, Puja, 1980-; Eric Jonsson School of Engineering and Computer Science. Open Networking Advanced Research (OpNeAR) Laboratory.In conventional (non-cooperative) radio networks, the data frames, that are corrupted by errors during the transmission in a fading environment, are retransmitted by the source. In cooperative radio networks, frame retransmission may be performed by a neighboring node that has successfully overheard the source’s frame transmission. The advantage of the latter is the spatial diversity that is provided by the cooperative node. In addition, the retransmitted frame may have incremental redundancy for improved performance. In this paper a simple automatic repeat request (ARQ) protocol is specified that takes advantage of coded cooperative communication in slotted, single-hop radio networks. An exact analytical formulation is presented to compute the delay experienced by Poisson arriving frames whose retransmission (when needed) is performed by one cooperative node. The study reports significant quantitative advantages of the coded cooperation ARQ protocol in terms of both throughput and latency, when compared to non-cooperative ARQ protocols.Item Chromatic dispersion and self-phase modulation in multi-hop multi-rate WDM rings(The University of Texas at Dallas, 2013-06-18) Cerutti, Isabella, 1973-; Fumagalli, Andrea; Potasek, Mary J.; Eric Jonsson School of Engineering and Computer Science. Open Networking Advanced Research (OpNeAR) Laboratory.; New York University. Courant Institute.When compared to first generation and single-hop optical networks, multi-hop and multirate (M & M) network architectures have the advantage of significantly reducing network design cost under a variety of wavelength-to-terminal cost ratios. This report investigates how fiber chromatic dispersion and self-phase modulation may affect such cost reduction in M & M WDM rings.Item Cooperative ARQ protocols in slotted radio networks(The University of Texas at Dallas, 2013-06-18) Cerutti, Isabella, 1973-; Fumagalli, Andrea; Gupta, Puja, 1980-; Eric Jonsson School of Engineering and Computer Science. Open Networking Advanced Research (OpNeAR) Laboratory.In conventional (non-cooperative) automatic repeat request (ARQ) protocols for radio networks, the corrupted data frames that cannot be correctly decoded at the destination are retransmitted by the source. In cooperative ARQ protocols, data frame retransmissions may be performed by a neighboring node (the relay) that has successfully overheard the source’s frame transmission. One advantage of the latter group of ARQ protocols is the spatial diversity provided by the relay. The first delay model for cooperative ARQ protocols is presented in this paper. The model is analytically derived for a simple set of retransmission rules that make use of both uncoded and coded cooperative communications in slotted radio network. The model estimates the delay experienced by Poisson arriving frames, whose retransmissions (when required) are performed also by a single relay. Saturation throughput, frame latency and buffer occupancy at the source, and relay are quantified and compared against two non-cooperative ARQ protocols.Item Destination-initiated wavelength-weighted reservation protocol in WDM rings(The University of Texas at Dallas, 2013-06-03) Pitchumani, Sudhakar, 1978-; Cerutti, Isabella, 1973-; Fumagalli, Andrea; Eric Jonsson School of Engineering and Computer Science. Open Networking Advanced Research (OpNeAR) Laboratory.In networks that require dynamic assignment of wavelengths, it is known that destination initiated reservation protocols lower the blocking robability - caused by unavailable wavelengths or convergence problems of the network status information -, when compared to source initiated reservation protocols [1]. Choosing the wavelength using weights based on past performance may further lower such blocking probability, when compared to random selection strategies [2]. This paper presents a Destination initiated Weighted-Wavelength Reservation DW2R protocol that improves the performance of destination initiated reservation protocol and does not require any additional signaling messages. Wavelength weights are computed based on past blocking probabilities and stored at the source. A meticulous simulation study carried out on ring networks reveals for the first time a number of interesting properties of the proposed DW2 R protocol: a reduced (backward) blocking probability when compared to other reservation protocols, a good scalability in the number of ring nodes (links) and in the number of wavelengths, and a contained performance degradation due to an increase of either the ring signaling latency or the frequency of traffic changes.Item High-speed self-configuring networks based on cost-effective plug-and-play optical (PPO) nodes(The University of Texas at Dallas, 2013-06-18) Fumagalli, Andrae; Hui, Rongqing; Maloberti, F. (Franco); Gregori, Stefano; Cerutti, Isabella, 1973-; Tacca, Marco, 1973-; Eric Jonsson School of Engineering and Computer Science.This proposal visualizes a future ad-hoc multi-gigabit network infrastructure connecting a very large number of inexpensive optical nodes. Such nodes will look like today’s Fast Ethernet switches, providing however, 2-3 orders of magnitude higher bandwidth, and larger geographical network coverage. Users will connect nodes using already installed fibers by a simple plug-and-play operation. Once connected, the Plug-and-Play Optical (PPO) nodes will continuously communicate with other nodes for a self-configuration of both network and nodes. An on-board optical micro-lab, advanced transmission models and an intensive signal processing are the key components to build a system that is able to intelligently adjust optical data flows and wavelength selection. The PPO node configuration will account for varying traffic patterns and changing conditions of the optical physical layer, e.g., introduction and removal of PPO nodes, aging of optical components, temperature changes, soft failure of network elements. The objective of this proposal is to identify the required technologies, to study protocols and algorithms, to develop suitable transmission models, to design and fabricate critical parts of an integrated optical micro-lab that will make the envisioned scenario a reality, and to amalgamate all the achieved results for proving the PPO node concept feasibility.Item Multi-rate and multi-hop optical carriers in WDM ring(The University of Texas at Dallas, 2013-04-18) Cerutti, Isabella, 1973-; Fumagalli, Andrea; Tacca, Marco, 1973-; Lardies, Ana; Jagannathan, Rajesh Shanmugavel, 1971-; Eric Jonsson School of Engineering and Computer Science. Center for Advanced Telecommunications Systems and Services (CATSS); Texas Higher Education Coordinating BoardTransparency of the optical layer offers the possibility to design a network that operates at varying transmission bit rates. While variable bit rate interfaces are being tested and will soon provide the possibility to optimally select the transmission rate for each lightpath, the potential advantages of relying upon multiple transmission rates in the optical network are ready yet to be fully explored. In this paper we define the concept of Multi-hop and Multi-rate (M&M) network in which the tributary signal is transmitted over a sequence of lightpaths, with each lightpath operating at its own transmission rate, which is determined by a number of factors including the end node's interface, amount of multiplexed traffic and cost of the network components. The potential advantages provided by the M&M network when compared to first generation optical networks (i.e., SONET/SDH), single- and multi-hop (constant bit rate) optical networks, are discussed in general and demonstrated numerically in a WDM ring. Presented results show that the network cost reduction achieved by the M&M design is a function of the cost ratio between the optical bandwidth (wavelengths) and the optical terminals.Item Plug and play optical (PPO) nodes: network functionalities and built-in fiber characterization techniques(The University of Texas at Dallas, 2007-05-07) Cerutti, Isabella, 1973-; Fumagalli, Andrea; Hui, Rongqing; Monti, Paolo, 1973-; Paradisi, Alberto; Tacca, Marco, 1973-; Eric Jonsson School of Engineering and Computer Science.Plug and play optical (PPO) nodes may be used to facilitate the deployment of optical networks. PPO nodes must be able to learn about the signal propagation properties of the surrounding optical fibers and make their wavelength routing decisions based on the collected data. This paper discusses what are the open challenges that must be overcome to provide cost effective and performing ad hoc networking solutions based on PPO nodes. Three possible PPO node hardware architectures trading off complexity, cost and functionalities are presented along with their built-in fiber characterization techniques.Item A practical perspective in designing mesh networks based on 1 : N self-healing wavelength division multiplexing rings(The University of Texas at Dallas, 2013-06-18) Fumagalli, Andrea; Tacca, Marco, 1973-; Cerutti, Isabella, 1973-; Masetti-Placci, Francesco; Jagannathan, Rajesh Shanmugavel, 1971-; Eric Jonsson School of Engineering and Computer Science. Department of Electrical Engineering.; US Army Space and Strategic Defense CommandA fundamental task of the optical layer in modern telecommunication systems consists of providing a fast protection mechanism against possible faults in the network. A particularly attractive protection technique in the optical layer is the so called shared line protection, in which network lines are protected using shared resources. A previous work of the authors formally describes the problem of minimizing the total wavelength mileage necessary in a Wavelength Routing mesh network to provide shared line protection. However, two practical issues remain to be addressed: the solution feasibility in presence of design constraints and the problem complexity in large size networks. This paper presents an approach to addressing the above two issues based on: 1) an algorithm that identifies a feasible solution with the minimal, possibly null, violation of the design constraints, 2) an intelligent pruning technique of the search space that reduces the complexity of the optimization problem. Using the proposed approach, a study on the total wavelength mileage is carried out for the European network (19 nodes) and the Pan American network (79 nodes) to assess the influence that some design constraints have on this cost function.Item Single-source single-relay cooperative ARQ protocols in TDM radio networks(The University of Texas at Dallas, 2013-06-18) Cerutti, Isabella, 1973-; Fumagalli, Andrea; Gupta, Puja, 1980-; Eric Jonsson School of Engineering and Computer Science. Open Networking Advanced Research (OpNeAR) Laboratory.; Scuola Superiore Sant’Anna. Center of Excellence for Communication Networks Engineering (CEIRC).In conventional (non-cooperative) automatic repeat request (ARQ) protocols for radio networks, the corrupted data frames that cannot be correctly decoded at the destination are retransmitted by the source. In cooperative ARQ protocols, data frame retransmissions may be performed by a neighboring node (the relay) that has successfully overheard the source’s frame transmission. One advantage of the latter group of ARQ protocols is the spatial diversity provided by the relay. The first delay model for cooperative ARQ protocols is derived in this paper. The model is analytically derived for a simple set of retransmission rules that make use of both uncoded and coded cooperative communications in slotted radio networks. The model estimates the delay experienced by Poisson arriving frames, whose retransmissions (when required) are performed also by a single relay. Saturation throughput, data frame latency, and buffer occupancy at both the source and relay are quantified and compared against two non-cooperative ARQ protocols.Item Single-source single-relay cooperative ARQ protocols in TDM radio networks(The University of Texas at Dallas, 2013-06-18) Cerutti, Isabella, 1973-; Fumagalli, Andrea; Gupta, Puja, 1980-; Eric Jonsson School of Engineering and Computer Science.In conventional (non-cooperative) automatic repeat request (ARQ) protocols for radio networks, the corrupted data frames that cannot be correctly decoded at the destination are retransmitted by the source. In cooperative ARQ protocols, data frame retransmissions may be performed by a neighboring node (the relay) that has successfully overheard the source’s frame transmission. One advantage of the latter group of ARQ protocols is the spatial diversity provided by the relay. The first delay model for cooperative ARQ protocols is derived in this paper. The model is analytically derived for a simple set of retransmission rules that make use of both uncoded and coded cooperative communications in slotted radio networks. The model estimates the delay experienced by Poisson arriving frames, whose retransmissions (when required) are performed also by a single relay. Saturation throughput, data frame latency, and buffer occupancy at both the source and relay are quantified and compared against two non-cooperative ARQ protocols.Item Threshold-based blocking differentiation in circuit switched WDM networks(The University of Texas at Dallas, 2013-06-11) Pitchumani, Sudhakar, 1978-; Cerutti, Isabella, 1973-; Fumagalli, Andrea; Eric Jonsson School of Engineering and Computer Science. Open Networking Advanced Research (OpNeAR) Laboratory.This paper introduces a centralized admission control mechanism, referred to as Threshold-based Blocking Differentiation (TBDijf), to differentiate the blocking probability experienced by various service classes in a circuit switched WDM network. The mechanism is based on multiple class-thresholds that indicate the minimum amount of capacity that must be available, prior to accommodating a request for a given service class. The performance of TBDiff is studied by means of an analytical framework and also an event-driven simulator. The results show a thorough matching of the analytical and simulation results and also demonstrate that high blocking differentiation among service classes can be obtained, without excessively increasing the overall (average) network blocking probability.