Performance analysis of realistic optical time division multiplexed wavelength routed networks

Application of optical time division multiplexing (OTDM) in wavelength routed optical networks greatly enhances the flexibility of bandwidth assignment because OTDM provides time division sub-channels in a wavelength to match the processing speed of electronic devices. Different types of such OTDM wavelength-routed (OTDM-WR) networks, assuming different levels of sophistication of the OTDM technology, have been proposed. The performance of these OTDM-WR networks improves with the time-slot routing capability of the intermediate nodes of the network. However, as the transmission rate increases up to hundreds of gigabits per wavelength channel, electronic processing of the time slots limits the achievable performance of the OTDM-WR networks. All-optical signal processing can overcome the electronics bottleneck, but the available all-optical signal processing capability is rather limited and cannot yet utilize the full potential of time-slot routing. Even with such limitations, current technologies, such as fast wavelength converters and micro-electromechanical system (MEMS) optical switches, can significantly enhance the performance of existing wavelength-routed networks by adding the OTDM capability, albeit limited. We develop time-slot routing schemes that require fast wavelength converters only and study the performance of these schemes by simulations on Manhattan street networks and a network with the topology of the AT&T North America OC-48 fiber network.published_or_final_versio

Performance model of deflection-routed multi-slot batch-transfer networks

published_or_final_versionWith the recently proposed multi-slot batch-transfer (MSBT) architecture, we can build optical packet switches using slow switching fabrics with reconfiguration time larger than the guard time between packets. Since MSBT switches can provide multichannel capability with no additional hardware, we propose to combine the multichannel and deflection routing approaches for packet contention resolution in MSBT networks. As there is no analytical performance model available, we derive the required model in this paper. Simulations show that the model is very accurate. © 2008 IEEE.link_to_subscribed_fulltextThe IEEE Global Telecommunications Conference (GLOBECOM 2008), New Orleans, LO., USA, 30 November-4 December 2008

Novel resource reservation schemes for optical burst switching

We propose to improve the throughput performance of optical burst switching by using regional controller nodes and window-based reservation. Both methods increase the information available to the intermediate nodes during scheduling decisions. Simulations show that the proposed reservation schemes provide significant improvement in the throughput performance compared with the original optical burst switching when the network is heavily loaded. © 2005 IEEE.published_or_final_versio

Deflection routing in slotted self-routing networks with arbitrary topology

A deflection routing algorithm that can be applied to a novel self-routing address scheme for networks with arbitrary topology is proposed. The proposed deflection routing algorithm can be implemented all-optically using bitwise optical logic gates. Besides the primary output link selection, alternate output link choices by a packet at each node in case of deflection are also encoded in the address header. Priority classes can also be defined in the proposed address scheme. The performance of the deflection routing algorithm is studied using the AT&T North America OC-48 optical fiber network topology.published_or_final_versio

Analysis of power line communications for last-hop backhaul in small cells deployment

Publicado en: :(2019-04-05),(José A. Cortes, Francisco J. Cañete, Matías Toril, Luis Díez, Alicia García-Mozos, "Analysis of power line communications for last-hop backhaul in small cells deployment", in Proceedings of the IEEE International Symposium on Power Line Communications and its Applications, 2019.),yEditor(IEEE)The purpose of this work is to study the feasibility of using power line communications (PLC) over outdoor public lighting networks (OPLN) for last-hop backhaul in small cell deployment. The analysis is based on actual noise measurements performed in two OPLN in the city of Málaga (Spain) and on a bottom-up channel simulator, which has been designed according to the physical characteristics and the common practices in such kind of networks. Estimations of the bit-rate achieved by PLC systems following the ITU-T Rec. G.9960 (G.hn) standard, are performed and discussed. Results indicate that PLC is a promising solution for this application.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Performance improvement methods for burst-switched networks

In this paper, we present a performance model of optical burst switching (OBS) that can explain the degradation of OBS throughput performance when the control packet processing time increases. We then use the proposed performance model to investigate three feasible methods to improve OBS performance without significantly increasing the implementation complexity: addition of simple fiber delay lines (FDLs), random extra offset time, and window-based channel scheduling (WBS). Additional FDLs can eliminate the negative impact caused by the variation of the offset time between control packets and data bursts. The random extra offset time approach does not require any additional hardware and computational capability in the nodes. If higher computational capability is available, WBS in general can provide better throughput improvement than that of random extra offset time when FDLs are used in the nodes to compensate the processing time. Simulation results show that a combination of the proposed methods can significantly improve OBS performance. © 2011 Optical Society of America.published_or_final_versio

Wavelength-routed networks with lightpath data interchanges

We observe that tunable wavelength converters (TWCs) that are traditionally installed in wavelength-routed (WR) networks for wavelength contention resolution can be further utilized to provide fast data switching between lightpaths. This allows us to route a data unit through a sequence of lightpaths from source to destination if a direct single lightpath connection is not available or if we want to minimize the overhead of setting up new lightpaths. Since TWCs have a tuning time of picoseconds, it may be possible to use the installed TWCs as lightpath data interchanges (LPIs) to improve the performance of WR networks without significant optical hardware upgrade. Compared with the multihop electronic grooming approach of lightpath networks, the LPI approach has a simpler WR node architecture, does not need expensive high-speed electrical multiplexers/routers, and does not sacrifice the bit-rate/format transparency of data between the source and destination. Our simulation results show that WR networks with LPIs can have much lower blocking probability than WR networks without LPIs if the traffic duration is short. We show that LPIs can also be used to provide new data transportation services such as optical time division multiplexing access (OTDMA) time-slotted service in WR networks. © 2010 OSA.published_or_final_versio

Performance Model of Multichannel Deflection-Routed All-Optical Networks With Packet Injection Control

Deflection routing is a feasible approach to resolve the output contention problem in packet-switched networks when buffering of packets is not practical. In this paper, we investigate the performance of multichannel deflection-routed networks with no packet injection control, strict packet injection control, and a simple token-bucket-based packet injection control. The analytical performance models of multichannel deflection-routed networks with strict packet injection control are derived. Simulation results show that the analytical models can accurately predict the performance regardless of the network topology, number of channels, and packet injection control methods. We observed that the end-to-end throughput-delay and the packet re-transmission performance at sources can be largely improved by using simple packet injection control mechanisms such as the proposed token-bucket-based method.postprin