{"id":835,"date":"2020-03-24T11:48:30","date_gmt":"2020-03-24T18:48:30","guid":{"rendered":"https:\/\/sierra.ece.ucdavis.edu\/?p=835"},"modified":"2020-03-25T10:56:13","modified_gmt":"2020-03-25T17:56:13","slug":"programmable-flexible-transceivers","status":"publish","type":"post","link":"https:\/\/sierra.ece.ucdavis.edu\/index.php\/2020\/03\/24\/programmable-flexible-transceivers\/","title":{"rendered":"Programmable Flexible Transceivers: Sliceable bandwidth variable transponders for elastic optical networks"},"content":{"rendered":"\n

Technology Overview<\/strong><\/p>\n\n\n\n

Elastic optical networking (EON)\n[1] enables efficient spectrum utilization by allocating variable bandwidth to\neach user according to their actual needs. Unlike WDM networks, EON utilizes\nthe optical spectrum divided into arbitrary or smaller frequency units (e.g.,\n12.5 or 25 GHz, also known as spectral slices). This allows various connections\n(flexpaths) to be set up using an arbitrary bandwidth of spectral slices of\narbitrary modulation format depending on the bandwidth, the distance, and the\nlink condition requests of the spectral slices for transmission. The\nflexibility in spectrum and bandwidth allocation together with variable\nmodulation formats allows for more optimized utilization of network resources\naccording to the given traffic demand and the link conditions. The network\nresource optimization spans temporal and spectral domains, and efficient and\neffective algorithms need to be part of the network control and management to\nallocate the available resources optimally. For instance, dynamic adaptation to\nthe varying traffic demand can lead to stranded and fragmented [2,3] spectral\nresources in EON, where there is no fixed spectral grid. Recent studies\ninvestigated spectral and temporal domain solutions for fragmentation-aware\nrouting, spectrum, and modulation format assignment (RSMA) [4,5] in 2D EON with\ntime and spectrum flexibility.<\/p>\n\n\n\n

 A major challenge for realizing transmitters\nand receivers for high-capacity flexible bandwidth networking is overcoming the\nelectronic bottleneck to enable scaling of single channel bandwidths using\nexisting electronics. A more general method for broadband waveform generation\nis based on dynamic optical arbitrary waveform generation (OAWG). The generated\narbitrary optical waveforms can include data waveforms in both single carrier\nmodulation formats and multicarrier modulation formats such as CoWDM and OFDM.\nHere, dynamic refers to continuous waveform generation, as opposed to\nlineby-line pulse shaping, which has time duration limitations typically on the\norder of tens of picoseconds. Spectral-slice based dynamic OAWG can create\ncontinuous, high-fidelity waveforms that overcome the limitations of rapidly\nupdating the modulations to a line-byline pulse shaper. Spectral-slice dynamic\nOAWG utilizes the parallel synthesis and coherent combination of many lower\nbandwidth spectral slices to create broadband data waveform. In contrast to\nmulticarrier systems, the spectral slice bandwidth is not related to the\nsubcarrier bandwidth of generated waveforms. This removes any restrictions on\nthe subcarrier bandwidth and its modulation format and is only limited by the\ntotal operational bandwidth of the OAWG transmitter. The parallel nature of\nthis transmitter structure enables bandwidth scalability without increasing the\nbandwidth demand on the supporting electronics. The complementary receiver is\noptical arbitrary waveform measurement (OAWM), in which a broadband, continuous\nbandwidth waveform is divided into many spectral slices for parallel\nmeasurement using independent digital coherent receivers.<\/p>\n\n\n\n

Current Research Activities<\/strong><\/p>\n\n\n\n

This\nproject pursues DOAWG\/DOAWM based bandwidth-variable optical transceiver\nrealized by high speed field programmable gate array (FPGA)-based digital\nsignal processing (DSP) techniques. In particular, UC Davis research team has\nbeen pursuing the following research efforts: <\/p>\n\n\n\n

  1. Design and implementation of real-time DOAWG\/DOAWM algorithms on FPAG. To migrating from the conventional offline DSP based DOAWG\/DOAWM, novel slicing and de-slicing algorithms which suitable for parallel realization on FPGA are required. On top of the DSP building blocks that can be found on traditional coherent receivers, such as adaptive equalizer, frequency offset estimators, and carrier phase recoveries. <\/li><\/ol>\n\n\n\n
    \"\"
    Figure 1. (a) Experiment setup for a novel FOE valiadation; (b) FPGA floorplan of the proposed FOE; (c) DSP implementation of the proposed FOE; (d) Experimentally results of the proposed FOE.<\/figcaption><\/figure>\n\n\n\n

    <\/p>\n\n\n\n

    References<\/strong><\/p>\n\n\n\n

    [1] P. J. Winzer, \u00e2\u20ac\u0153Making Spatial Multiplexing A Reality,\u00e2\u20ac\u009d\nNature Photonics, vol. 8, 2014, pp. 345\u00e2\u20ac\u201c48. [2] R. Essiambre et al., \u00e2\u20ac\u0153Capacity\nLimits of Optical Fiber Networks,\u00e2\u20ac\u009d J. Lightwave Tech., vol. 28, 2010, pp.\n662\u00e2\u20ac\u201c701. <\/p>\n\n\n\n

    [3] D. Richardson, J. Fini, and L. Nelson, \u00e2\u20ac\u0153Space-Division\nMultiplexing in Optical Fibres,\u00e2\u20ac\u009d Nature Photonics, vol. 7, 2013, pp. 354\u00e2\u20ac\u201c62. <\/p>\n\n\n\n

    [4] B. Guan et al., \u00e2\u20ac\u0153Free-Space Coherent Optical Communication\nwith Orbital Angular, Momentum Multiplexing\/Demultiplexing Using a Hybrid 3D\nPhotonic Integrated Circuit,\u00e2\u20ac\u009d Optics Express, vol. 22, 2014\/01\/13 2014, pp.\n145\u00e2\u20ac\u201c56. <\/p>\n\n\n\n

    [5] N. Bozinovic et al., \u00e2\u20ac\u0153Terabit-Scale Orbital Angular\nMomentum Mode Division Multiplexing in Fibers,\u00e2\u20ac\u009d Science, vol. 340, June 28,\n2013 2013, pp. 1545\u00e2\u20ac\u201c48.<\/p>\n","protected":false},"excerpt":{"rendered":"

    Technology Overview Elastic optical networking (EON) [1] enables efficient spectrum utilization by allocating variable bandwidth to each user according toContinue Reading<\/a><\/span><\/p>\n","protected":false},"author":1,"featured_media":836,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[44,35],"tags":[],"class_list":["entry","author-hluucdavis-edu","post-835","post","type-post","status-publish","format-standard","has-post-thumbnail","category-programmable-flexible-transceivers","category-technologies"],"_links":{"self":[{"href":"https:\/\/sierra.ece.ucdavis.edu\/index.php\/wp-json\/wp\/v2\/posts\/835","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sierra.ece.ucdavis.edu\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sierra.ece.ucdavis.edu\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sierra.ece.ucdavis.edu\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sierra.ece.ucdavis.edu\/index.php\/wp-json\/wp\/v2\/comments?post=835"}],"version-history":[{"count":1,"href":"https:\/\/sierra.ece.ucdavis.edu\/index.php\/wp-json\/wp\/v2\/posts\/835\/revisions"}],"predecessor-version":[{"id":837,"href":"https:\/\/sierra.ece.ucdavis.edu\/index.php\/wp-json\/wp\/v2\/posts\/835\/revisions\/837"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/sierra.ece.ucdavis.edu\/index.php\/wp-json\/wp\/v2\/media\/836"}],"wp:attachment":[{"href":"https:\/\/sierra.ece.ucdavis.edu\/index.php\/wp-json\/wp\/v2\/media?parent=835"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sierra.ece.ucdavis.edu\/index.php\/wp-json\/wp\/v2\/categories?post=835"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sierra.ece.ucdavis.edu\/index.php\/wp-json\/wp\/v2\/tags?post=835"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}