光通信研究最新文献

{"title":"High speed optical wireless demonstrators in the OMEGA project: Summary and conclusions","authors":"D. O’brien","doi":"10.1109/NOC-OCI.2013.6582883","DOIUrl":"https://doi.org/10.1109/NOC-OCI.2013.6582883","url":null,"abstract":"Two high-speed optical wireless demonstrators were produced within the EU funded framework 7 OMEGA project. One of these operates at 1.25Gbit/s demonstrating high data rates, and the other offering `room scale' coverage at 280 Mbits/s. Details of design, implementation and testing of each are reviewed, together with the challenges of such systems and future directions for work in this area.","PeriodicalId":57196,"journal":{"name":"光通信研究","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77979198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atmospheric turbulence on FSO at 785 nm","authors":"L. Csurgai-Horváth, I. Frigyes, J. Bitó, P. Kantor","doi":"10.1109/NOC-OCI.2013.6582892","DOIUrl":"https://doi.org/10.1109/NOC-OCI.2013.6582892","url":null,"abstract":"The atmospheric turbulence is one of the cause of channel impairments of the free space optical links. This phenomenon appears even in case of clear sky conditions and according to the literature it may affect the availability of the connection. In this paper the atmospheric turbulence will be studied, based on longterm measurement data. The measurements were performed on a 930m long free space optical link that operates at 785 nm wavelength.","PeriodicalId":57196,"journal":{"name":"光通信研究","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86245775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analytical expression of FSO link misalignments considering Gaussian beam","authors":"J. Poliak, P. Pezzei, E. Leitgeb, O. Wilfert","doi":"10.1109/NOC-OCI.2013.6582874","DOIUrl":"https://doi.org/10.1109/NOC-OCI.2013.6582874","url":null,"abstract":"In the paper, an optical wireless link for point-to-point communication is analyzed. Its main focus is the analysis of the influence of various misalignments on the received power. Analysis includes influence of the tilt of the transmitter and the receiver as well as their mutual misalignment respecting the Gaussian intensity distribution of the transmitted beam in terms of geometrical optics. As a result of the analysis, expression for influence of the various misalignments on the received power are presented. For the simulation of the link, a MATLAB environment was used. The conclusion contains synthesis of the simulations results. The main contribution is in consideration of the Gaussian beam distribution of the transmitted beam and its analysis for precise prediction of geometrical losses for individual free-space optical links.","PeriodicalId":57196,"journal":{"name":"光通信研究","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75293595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Large data center interconnects employing hybrid optical switching","authors":"M. Fiorani, M. Casoni, S. Aleksic","doi":"10.1109/NOC-OCI.2013.6582869","DOIUrl":"https://doi.org/10.1109/NOC-OCI.2013.6582869","url":null,"abstract":"Current data centers (DCs) networks rely on electronic switching and point-to-point interconnects. When considering future DC requirements, point-to-point interconnects will lead to poor network scalability and large power consumption. For this reason several optical switched interconnects for DCs have been recently proposed. However, the proposed optical switching solutions suffer from low flexibility and are not able to provide service differentiation. Furthermore, very few studies evaluate possible improvements in energy efficiency offered by optical switching solutions. In this paper we introduce a novel architecture of interconnects for DCs based on hybrid optical switching (HOS). HOS combines three different optical switching paradigms, namely circuit, burst and packet switching within the same network. Furthermore, HOS envisages the use a two parallel optical switches, a slow and low power consuming switch for the transmission of data using circuits and long bursts, and a fast switch for the transmission of packets and short bursts. The possibility of choosing between circuits, bursts and packets ensures the flexibility required by future DCs. At the same time, the option to select the most suitable switch technology for each data flow guarantees high transmission efficiency and low power consumption.","PeriodicalId":57196,"journal":{"name":"光通信研究","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72926867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An all-optical Sampler for digitising Radio-over-Fibre transceivers","authors":"R. Ribeiro, Frédéric Lucarz, B. Fracasso","doi":"10.1109/NOC-OCI.2013.6582864","DOIUrl":"https://doi.org/10.1109/NOC-OCI.2013.6582864","url":null,"abstract":"In this paper it is proposed and designed an all-optical Sampler (o-Sampler) intended to be part of future optical Digitising Radio-over-Fibre (o-DRoF) transceivers. It is based on the Semiconductor Laser Amplifier Loop Mirror (SLALOM) configuration thus using the nonlinearities of a semiconductor optical amplifier (SOA) in cross-switching regime. The proof-of-principle is established by computer simulations using 500 MHz analogue signal and 2.5 GS/s sampling pulses both in the C-band. The proposed o-Sampler outputs real-time generated optical samples from an analogue RoF signal. The simulated device is rather compact, polarisation independent, potentially optically integrable and requires few mW of sampling peak power.","PeriodicalId":57196,"journal":{"name":"光通信研究","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75187444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of the atmospheric turbulence on the laser beam","authors":"P. Barcik, L. Hudcová, O. Wilfert","doi":"10.1109/NOC-OCI.2013.6582872","DOIUrl":"https://doi.org/10.1109/NOC-OCI.2013.6582872","url":null,"abstract":"Free space optical (FSO) communication links offer a number of advantages over radio frequency links. Main advantages of FSO communication links are electromagnetic compatibility, license-free band and high data rate. However, reliability of these links is highly dependent on atmospheric and weather conditions. An optical wave propagating through the atmospheric transmission media is very sensitive on variety of atmospheric effects, e.g. beam wander, fluctuation of optical intensity and loss of spatial coherence. The purpose of this paper is to present the measurement of the distribution of the relative optical intensity variance in the Gaussian beam. The measurement of the spatial coherence is also presented.","PeriodicalId":57196,"journal":{"name":"光通信研究","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88864197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multipath routing in Path Computation Element (PCE): Protocol extensions and implementation","authors":"Xiaomin Chen, Yuesheng Zhong, A. Jukan","doi":"10.1109/NOC-OCI.2013.6582871","DOIUrl":"https://doi.org/10.1109/NOC-OCI.2013.6582871","url":null,"abstract":"The Path Computation Element (PCE) and PCE communication Protocol (PCEP) have been standardized by the IETF. The scalability of PCE and its capability of constrained path computation make it especially attractive to carriers. Considering the latest extensions on related protocols, PCE has become the de-facto standard in connection service provisioning, especially in the carrier grade networks with strict QoS requirements. Whereas the PCE frameworks proposed to date have exclusively considered single path computation, the increasing demand for flexible services with high bandwidth requirement is driving PCE towards multipath techniques. This paper proposes the first implementation and protocol extensions of PCE with capability of multipath computation in line with PCE standards. We show that the overhead, i.e., signaling delay, caused by the multipath extensions in the PCEs is acceptable, while the blocking ratio of connection requests can be significantly reduced. We also suggest that the number of paths can be limited in the multipath routing algorithms to reduce the overhead caused by multipath extensions at a price of slight increase of blocking ratio. The results show that the presented multipath PCE system is scalable in large networks, with average signaling delay in the order of milliseconds. Therefore, it is feasible in practice and it can be beneficial for transport networks with emerging new applications, such as optical and Carrier Ethernet networks.","PeriodicalId":57196,"journal":{"name":"光通信研究","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83194505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Virtual ring based protection for Time-Domain Wavelength Interleaved Network","authors":"L. Sadeghioon, Ion Popescu, B. Uscumlic, P. Gravey, A. Gravey","doi":"10.1109/NOC-OCI.2013.6582877","DOIUrl":"https://doi.org/10.1109/NOC-OCI.2013.6582877","url":null,"abstract":"We propose a protection scheme for Time-Domain Wavelength Interleaved Network (TWIN), an optical burst switching technology for transport networks, where each destination node uses a dedicated wavelength, while sources are equipped with fast tunable lasers. TWIN is composed from several multipoint-to-point trees built on top of a mesh network linking sources and destinations. Each multipoint-to-point tree in TWIN has its root in a destination node, and is thus used for the reception at a single, unique wavelength. In the proposed method resource allocation is centrally performed in order to avoid contention on the multipoint-to-point trees while optimizing source activity. We propose using a virtual ring joining all sources and destinations in order to support both an out-of-band control channel and all protection paths. The control channel may be used in particular to carry messages related to network discovery, synchronization and protection issues. Synchronization and failure notifications (generated by standard optical layer monitoring procedures) are processed by the central element in charge of resource allocation. The proposed TWIN layer protection approach avoids using lower layer protection techniques, which may strongly impact the fiber length distribution, and thus the associated scheduling mechanism, inside the different multipoint-to-point trees. The use of a single virtual control ring is well suited to networks with a limited extension such as metro networks. Our approach can however be extended to larger scale networks by using several control rings. We describe an algorithm to cover a large network operated by TWIN with minimum number of interconnected rings, taking into account the maximum transparent reach for protection paths.","PeriodicalId":57196,"journal":{"name":"光通信研究","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83920302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The priority wavelength release protocol for dynamic wavelength allocation in WDM-TDMA PONs supporting random and quasi-random bursty traffic","authors":"I. Moscholios, M. Logothetis, V. Stylianakis, J. Vardakas","doi":"10.1109/NOC-OCI.2013.6582876","DOIUrl":"https://doi.org/10.1109/NOC-OCI.2013.6582876","url":null,"abstract":"Passive Optical Networks (PONs) are attractive fiber-based access systems providing broadband access solutions at a low cost. A hybrid Wavelength Division Multiplexing (WDM) - Time Division Multiple Access (TDMA) PON is a favorite PON configuration, in which the researchers have drawn much attention. We have analysed and proposed several protocols for dynamic wavelength allocation in a WDM-TDMA PON, by separately considering random or quasi-random input-traffic. By modelling the bursty in-service traffic as an ON-OFF model, we have proposed three protocols for random call arrivals. The same protocols have also been proposed for quasi-random call arrivals, resulting however in different evaluation conclusions (than in the case of random arriving calls). This fact gave rise to a fourth protocol, the Priority Wavelength Release (Pr-WR) Protocol, suitable for quasi-random input-traffic. According to this protocol, the service-classes accommodated in the PON are distinguished in two groups: the high and low priority groups. A connection between an Optical Node Unit (ONU) and the Optical Line Terminal (OLT) (the common link of the PON) can be terminated and the occupied wavelength is released, only when the common link is empty or holds low priority calls in state OFF. In this paper, we examine the Pr-WR protocol in the WDM-TDMA PON under a mixture of quasi-random and random arriving calls. The ON-OFF teletraffic model for the mixture of random and quasi-random arrivals is presented. We evaluate the behaviour of this protocol in comparison with the other three protocols in respect of: a) the Connection Failure Probability (due to the unavailability of a wavelength), and b) the Delay (low priority calls may delay in state OFF, until a new wavelength becomes available upon a new call arrival). For the Pr-WR Protocol, we also calculate the Call Blocking Probability (due to the restricted bandwidth of the wavelength) and the Burst Blocking Probability (burst of calls delays in state OFF, due to temporal unavailability of wavelength bandwidth). We come to safe conclusion which is favourite for the Pr-Wr protocol.","PeriodicalId":57196,"journal":{"name":"光通信研究","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89302307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Online artificial neural network equalization for a visible light communications system with an organic light emitting diode based transmitter","authors":"P. Haigh, Zabih Ghassemlooy, I. Papakonstantinou, S. Rajbhandari","doi":"10.1109/NOC-OCI.2013.6582882","DOIUrl":"https://doi.org/10.1109/NOC-OCI.2013.6582882","url":null,"abstract":"This paper presents the use of a digital signal processor (DSP) to implement an artificial neural network (ANN) equalizer in an organic light emitting diode (OLED) based visible light communications (VLC) system for the first time. The ANN is used to counteract the inter-symbol interference (ISI) experienced when the transmission rate exceeds the system modulation bandwidth. The link is made up of an OLED as transmitter with a silicon photodetector as receiver. The bandwidth off the OLED is 93 kHz, enforcing a low pass transfer function on the system. The bit rate achieved is 500 kb/s, which agrees well with similar systems that have been processed with MATLAB.","PeriodicalId":57196,"journal":{"name":"光通信研究","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77192287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}