With the advent of cloud computing,over-the-top on-demand video (Netflix, YouTube, Hulu etc.), high definition TVthere has been immense rise in the IP traffic with most aggressive rise seen infinancial sector thus demanding huge scalability and availability of the datacenters. The standardization of 100G has been a massive success for opticalindustry and with the collaboration of ITU-T and IEEE, has led to thecommercial availability of products featuring 100G in the market.
But the strive forimproving the bandwidth need and network capacity has required to look what’sahead 100G. As 40G and 100G are already standardized, the next Ethernet ratewith OTN is supposed to be 400G or 1T.The Task Force that has been appointedfor 400G are going through many architectures based on advanced modulationformats including 16 channels x 25Gb/s NRZ, 8 channels × 50 Gb/s duo binary andPAM-4, 4 channels × 100 Gb/s PAM4, hybrid CAP-16/QAM- 16, and QAM-16-OFDM. Amongthese, all except 16 channels x 25 Gb/s NRZ shows greater power efficiencyimprovement while 16 channels x 25 Gb/s NRZ provides best optical power budgetmargin. In order to make 400G commercially feasible, there is a need for denserphotonic integration as the optical parallelization will increase compared tothe standards set by 100G Ethernet. The issues with high lane rates can be addressedusing advance format of modulation with photonic integration.
Looking at 1T Ethernetand OTN, it requires great extent of parallel transport in LAN and moderatespectral efficiencies in WAN. There have been experiments with results of 1.2Tb/soptical super channels, but solutions to such results needs substantial opticalparallelization. Under WAN, a move from 8bit/s/Hz (which is for 400G) to ahigher value is extremely difficult, but nevertheless not impossible.
Resultslike this makes 400G much more achievable as the next target for LAN and WAN.The growing needs ofoperators and end users requires network change in terms of addition ofstations/ improved reliability and cost-efficiency. Ethernet requires to copeup with situations, thus adapting and evolving to all the levels of network changes.Ethernet has its widespread use in transport, data centers, data connectivityservices which asks for new improved standards to address market demands. Wehave seen Ethernet evolving from shared CSMA/CD to switched point-to-point Ethernetand then bringing multi-lane technology over shared media of passive opticalnetworks. Now Ethernet has undertaken new brand by providing common transport platformfor control and multimedia applications.
The introduction of 40Gband 100Gb Ethernet standards for the very first time, saw the Ethernet networkat 40G and 100G. This was called High-Speed Optical Point-to Point Links. Keepinginto account the huge demand of customers and the network providers, theoptical standards for 40G and 100G aims at reducing the cost and complex natureof broad deployment of 100G Ethernet.
Then we had EPON which provided low costdeployment of optical access lines from carrier’s central office to customersite. Even though EPON was hugely successful, there were issues in addressingproblems such as deployment of EPON architecture in rural areas in costeffective manner, how to decrease the cost of connection per subscriber,serving more people at longer distance. To address all these issues cameExtended EPON Taskforce.Next there was a shift from MPEG-2to MPEG-4 video distribution over IP Ethernet.
This aimed at mixing EPON and EPoCwhile reusing existing coaxial distribution infrastructure along withfiber-deep access technologies. Metro Ethernet Forum (MEF) service performanceand competitive service level agreements (SLAs), are all being managed by Dataover Cable Service Interface Specification (DOCSIS) Provisioning of EPON technology,which is jointly developed by operators, vendors, and CableLabs. This was howEPON Protocol was tied together to work with coaxial.Ethernet continues to evolve by providingsupport to new media types, addressing new application space. It has nowentered in the new market of Automotive Industry as it has variety of solutionsfor optical media and electrical backplanes. The modern cars have infotainment,auto braking, collision avoidance, GPS which creates huge traffic for in carnetwork, all of which was not managed in the previous automotive networks.Having new standards for 40G and 100G already in the market, Ethernet now hasbroader market for products that are more cost effective, decreases complexityand power consumption.