Review of Field Trials of Terrestrial 400G and Other Higher Data Rate Systems Beyond 100G


Over the past five years, many operators and service providers have been trialing 400G technologies on their live networks. In this article, we summarize findings from the review of over 80 trials throughout the world. The review focuses on operators, system vendors, technology options and reach achieved.

Why 400G?

Internet traffic continues to approximately double every year driven by innovative digital applications, video streaming and other online activities.  Such historical data rate demands detected that the industry develop 400Gb/s systems and beyond for current and future bandwidth requirements. 100G coherent systems, which came across as an overkill when engineers first initiated their R&D, are now becoming widely deployed. Although many operators will upgrade their capacity by adding 100G DWDM channels to their networks, eventually it will cost less per bit deploying 400G compared to 4x100Gb/s DWDM, for example.

Evidence of the relevance of 400G is already starting to show as suppliers like CIENA are already shipping gear to some customers. According to Cignal AI’s forecast, both 100G and 400G coherent systems will be widely deployed at the edge of the network by the end of 2021.

Market Reality Check for 10G to 400G Transmission Systems

By addressing 400G we are in no way suggesting that every network will have to migrate to 400G anytime soon. 10G DWDM systems will remain relevant in some networks for many years to come.  In some emerging markets, operators are only just starting to migrate from SDH systems to 10G DWDM systems. Others are planning to migrate from 10G to 100G which is expected to be more widely deployed over the years. Some will opt to use 100G and/or 400G in high traffic links and maintain 10G systems elsewhere. Some service providers who were expected to be early adopters of 400G are opting instead to migrate to 200G first.

What is important is for network planners and designers to be cognizant of network trends and the challenges of deploying higher data rate systems on existing infrastructure. Since fiber optic infrastructure is intended to last for decades, it is important that designers of network infrastructure intended of 10G or 100G today, design with upgradeability requirements in mind. If history is anything to go by, it is highly unlikely that infrastructure installed today for 10G or 100G will be used for the same data rates 20 to 30 years from now.

400G and Other High Transmission Systems

In all deployed coherent 100G systems, polarization division multiplexed-quadrature phase shift keying (PDM-QPSK) modulation is used to improve the system spectral efficiency. Without a change in modulation format from 10G to 100G, 16x100Gb/s DWDM channels would consume the same spectrum as 160x10Gb/s DWDM channels, thereby defeating the whole purpose of migrating to higher data rates. By using QPSK in 100G systems over NRZ-OOK used in 10G systems, the spectral efficiency is improved form 0.2 bit/s/Hz to 2 bit/s/Hz over 50GHz DWDM spacing.

In migrating from 100G to 400G, spectral efficiency should also be improved. Quadrature amplitude modulation QAM in the form 2n-QAM, where n > 2 is the constellation order, is one option that is being used. Thus, modulation formats of 8-QAM, 16-QAM, 32-QAM… are being used in 400G and other transmission rates beyond 100G.

Unfortunately, these modulation schemes require more system optical signal to noise ratio (OSNR) and have a profound impact on the system reach because they are more prone to laser phase noise and fiber optic non-linearities. For example, a single carrier 16-QAM 400Gb/s signal over standard G.652 fiber with EDFAs and no Raman amplification could be limited in reach to only 200km. This does not meet the requirements for metro networks, let alone long-haul and ultra-long-haul networks. For a more detailed analysis, review the OIF article – Technology Options for 400G Implementation.

To improve OSNR and reach, a combination of several approaches is used. This includes the use of ultra-low loss fiber, Raman amplification and superchannels. In a superchannel, several optical carriers are combined to achieve a composite signal of the desired data rate. For example, 2x200Gb/s signals are combined to achieve 400Gb/s. For ultra-long reach, 4x100Gb/s signals are combined and PDM-QPSK modulation is used. Superchannels differ from DWDM signals because to the user, a superchannel is not distinguishable from a single carrier of the same data rate.

Summary of 400G Trials

In order to evaluate the upgradeability of their fiber optic data transmission networks, many operators and service providers have been trialing 400G and other higher data rate systems on their live networks. We have reviewed over 80 of these trials with the aim of answering the following questions:

  1. What progress has been made towards the widespread deployment of 400G and other higher data rate systems?
  2. Considering the spectral efficiency – reach (OSNR) trade-off in 400G, what modulation schemes are being used?
  3. Whose vendor equipment is mostly being used in the 400G trials?
  4. Which operators are trialing 400G?

Our review has demonstrated that 400G technology is now well developed and ready for widespread deployment by those who require it. In addition to 400G, 150G, 200G, 300G, 500G, 800G, 1T, 1.4T and 1.5T have also been successfully trialed.

In most 400G implementations, superchannels and several modulation formats are being used. 2×200 Gb/s using 16-QAM modulation is mostly used for links and data center interconnects less than 500km in reach while 4x100Gb/s with QPSK modulation is used for longer reach. Similarly, 1T is implemented using 5x200Gb/s or 10x100Gb/s carriers.

Most leading vendors have partnered with one or more operators or service providers to successfully trial 400G or other higher data rates. Adva, Alcatel Lucent, CIENA, Coriant, Huawei and Infinera are some of the leading 400G system vendors.

All leading telecommunication operators, data center operators and IXPs throughout the world have trialed 400G and/or other higher data rate systems beyond 100G. The list of trials is provided in the table below.

Most technical concepts mentioned in this article are discussed in detail in the CONA and CONE optical networking classes.

Carrier/Service providerPlatformData RateImplementationModulationReachYear
PSNCADVA Optical FSP 3000 CloudConnect400 Gb/s2x200Gbps16-QAM385km2016
City of Cape TownADVA Optical FSP 3000 CloudConnect400 Gb/s1x400Gbps8-QAM100km2016
City of Cape TownADVA Optical FSP 3000 CloudConnect300 Gb/s1x300Gbps8-QAM100km2016
City of Cape TownADVA Optical FSP 3000 CloudConnect200 Gb/s1x200Gbps8-QAM100km2016
Telefonica GermanyADVA Optical FSP 3000 CloudConnect200 Gb/s1x200Gbps16-QAM290km2017
NetnodADVA Optical FSP 3000 CloudConnect400 Gb/s2x200Gbps16-QAM100km2017
InterNexaADVA Optical FSP 3000 CloudConnect200 Gb/s1x200Gbps16-QAM1040km2017
InterNexaADVA Optical FSP 3000 CloudConnect200 Gb/s1x200Gbps16-QAM370km2017
BTAlcatel-Lucent PSE1.4Tb/s7x200Gbps16-QAM410km2014
Ontario Research and Innovation Optical Network (ORION)Alcatel-Lucent PSE400 Gb/s2x200Gbps16-QAM15km2014
Telekom AustriaAlcatel-Lucent PSE400 Gb/s2x200Gbps16-QAM140km2014
T-Mobile Czech RepublicAlcatel-Lucent PSE400 Gb/s2x200Gbps16-QAM320km2015
OrangeAlcatel-Lucent PSE400 Gb/s2x200Gbps16-QAM465km2013
SaskTelAlcatel-Lucent PSE400 Gb/s2x200Gbps16-QAM250km2013
TelefonicaAlcatel-Lucent PSE400 Gb/s2x200Gbps16-QAM650km2013
Shaw CommunicationsAlcatel-Lucent PSE400 Gb/s2x200Gbps16-QAM400km2013
NextgenAlcatel-Lucent PSE400 Gb/s2x200Gbps16-QAM350km2016
Vodafone SpainAlcatel-Lucent PSE400 Gb/s2x200Gbps16-QAM400km2015
AlestraAlcatel-Lucent PSE400 Gb/s2x200Gbps16-QAM2014
BTAlcatel-Lucent PSE1.4Tb/s7x200Gbps16-QAM60km2014
T-SystemsAlcatel-Lucent PSE400 Gb/s2x200Gbps16-QAM2013
ZainAlcatel-Lucent PSE400 Gb/s2x200Gbps16-QAM2013
AT&TCiena WaveLogic Ai400 Gb/s1x400Gbps32-QAM300km2017
Vodafone New ZealandCiena WaveLogic Ai400 Gb/s1x400Gbps32-QAM2017
KVHCiena 6500 Packet-Optical Platform400 Gb/s2x200Gbps16-QAM660km2015
SprintCiena 6500 Packet-Optical Platform400 Gb/s2x200Gbps16-QAM2013
ESnet and NERSCCiena 6500 Packet-Optical Platform400 Gb/s2x200Gbps16-QAM16km2015
ComcastCiena 6500 Packet-Optical Platform1 Tb/s5x200Gbps16-QAM1,000 km2017
MobilyCiena 6500 Packet-Optical Platform1 Tb/s5x200Gbps16-QAM2014
CenturyLinkCiena 6500 Packet-Optical Platform1 Tb/s5x200Gbps16-QAM2015
BTCiena 6500 Packet-Optical Platform800 Gb/s4x200Gbps16-QAM410km2013
CANARIECiena 6500 Packet-Optical Platform300 Gb/s1x300Gbps8-QAM1440km2016
TDFCiena 6500 Packet-Optical Platform1 Tb/s5x200Gbps16-QAM188km2014
Reliance Jio InfocommCiena 6500 Packet-Optical Platform200 Gb/s1x200Gbps16-QAM2017
OrangeCoriant CloudWave Optics1 Tb/s5x200GbpsQPSK, 8-QAM, 16-QAM, 32-QAM, 64-QAM762km2015
NTT ComCoriant Groove G30400 Gb/s2x200Gbps16-QAM2017
Telefonica GermanyCoriant Groove G30200 Gb/s1x200Gbps16-QAM 290km2017
AT&TCoriant Groove G30400 Gb/s2x200Gbps 150G 8-QAM, 200G 16-QAM364km2017
A1 TelekomCoriant Groove G30400 Gb/s2x200Gbps8-QAM660km2013
FunetCoriant CloudWave Optics400 Gb/s2x200Gbps 150G 8-QAM, 200G 16-QAM475km2016
NBNCoriant Coriant hiT 7300 DWDM1 Tb/s5x200Gbps 150G 8-QAM, 200G 16-QAM1066km2014
TeliaSoneraCoriant Coriant CloudWave400 Gb/s2x200Gbps8-QAM/16-QAM1634km2015
Allied FiberCoriant hiT 73001 Tb/s5x200Gbps16-QAM1700km2014
NetiaCoriant hiT 7300400 Gb/s2x200Gbps16-QAM2013
Telia CarrierCoriant hiT 7300200 Gb/s1x200Gbps16-QAM1089km2017
Netcom ECI Apollo400 Gb/s2x200Gbps16-QAM204km2017
CESNET ECI Apollo400 Gb/s2x200GbpsFlexible, various2000km2015
Atman ECI Apollo400 Gb/s2x200GbpsFlexible, various2016
Comlink ECI Apollo1 Tb/s5x200Gbps16-QAM286km2014
DFR (German Research Network) ECI Apollo1 Tb/s5x200Gbps16-QAM and OFDM4600km2014
DeiCECI Apollo and Ericsson400 Gb/s2x200Gbps16-QAM2017
TelstraEricsson SPO 14001 Tb/s5x200Gbps16-QAM995km2013
Telefonica SpainEricsson MHL 3000400 Gb/s2x200Gbps16-QAM280 km2012
Bright House NetworksFujistu Fujitsu FLASHWAVE 9500800 Gb/s4x200Gbps16-QAM, QPSK,  DPSK2014
Mid-Atlantic Crossroads (MAX)Fujistu Fujitsu FLASHWAVE 9500800 Gb/s4x200GbpsQPSK and 16-QAM2014
BTHuawei (Platform not provided)400 Gb/s2x200Gbps16-QAM200km2015
KPN InternationalHuawei (Platform not provided)400 Gb/s2x200Gbps16-QAM540km2012
Vodafone TurkeyHuawei OptiX OSN9800400 Gb/s2x200Gbps16-QAM570km2015
EXATELHuawei (Platform not provided)400 Gb/s2x200Gbps16-QAM2013
China TelecomHuawei (Platform not provided)400 Gb/s2x200Gbps16-QAM2017
Telefonica ChileHuawei (Platform not provided)400 Gb/s2x200Gbps16-QAM2013
China MobileHuawei (Platform not provided)400 Gb/s2x200Gbps16-QAM and QPSK2014
EtisalatHuawei (Platform not provided)400 Gb/s2x200Gbps16-QAM170km2014
TeliaSoneraInfinera DTN-X500Gb/s5x500Gbps16-QAM1105km2011
MBCInfinera DTN-X1 Tb/s10x100GbpsQPSK2014
DANTEInfinera DTN-X1 Tb/s10x100GbpsBPSK, QPSK, 16-QAM and 8QAM2014
FacebookInfinera DTN-X1 Tb/s10x100GbpsQPSK3998km2015
GlobeNetInfinera DTN-X1 Tb/s10x100GbpsQPSK23500km2014
FSUE ZNIISInfinera DTN-X500 Gb/s5x100GbpsQPSK1175km2013
XO CommunicationsInfinera500 Gb/s5x100GbpsQPSK1348km2010
NTTNEC and Fujitsu400 Gb/s2x200GbpsQPSK, 8-QAM, 16-QAM1500km2014
Deutsche TelekomNokia 1830 PSS Portfolio1 Tb/s10x100GbpsProbabilistic Constellation Shaping (PCS)2016
Ooredoo AlgeriaNokia 1830 PSS Portfolio1 Tb/s10x100GbpsQPSK200km2016
Orange PolandNokia 1830 PSS Portfolio250 Gb/s1x250Gbps16-QAM870km2016
Orange PolandNokia 1830 PSS Portfolio1.5 Tbb/s6x250Gbps16-QAM870km2016
AT&TOpen source router platform400 Gb/s2x200Gbps16-QAM2017
NTTunknown400 Gb/s2x200Gbps16-QAM2015
China Unicomunknown400 Gb/s2x200Gbps16-QAM2016
Deutsche TelekomZTE WASON solution1 Tb/s10x100GbpsQPSK and 16-QAM2150km2012
T-Mobile AustriaZTE WASON solution400 Gb/s2x200Gbps16-QAM475km2016
China TelecomZTE WASON solution1 Tb/s10x100GbpsQPSK3200km2013
TRUEZTE WASON solution400 Gb/s2x200GbpsQPSK and 16-QAM2017
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