OTN
OTN
OTN
Talk Agenda
Background
Drivers for 40 & 100G Is the technology ready? Does it cost in? What are we doing in BT? Aims Key technologies Trial infrastructure and designs Location/system configuration Evaluation areas Results and findings
Requirement for Transport platforms to support high bit-rate (40/100GigE) client ports
IEEE 802.3 BA standards were ratified June 2010 Appropriate support for transparent transport of 40GbE and 100GbE over standard OTN rates Leading router/switch vendors now support 40/100 GigE interfaces and need transport
Typically DWDM systems support up to ~80 10Gbit/s ls i.e. ~800Gbit/s per fibre 100Gbit/s wavelengths gives us up to 8Tbit/s per fibre!
We have been trialling and evaluating 100G technology to understand its performance in BTs networks
BT Strategic vendors
Understand strategic vendor capabilities and influence their product development and specification Demonstrate and develop BTs technical capability in high speed network technology
British Telecommunications plc
CD tolerance
PMD tolerance Nonlinearity Cost Power consumption
Very High
Very High Medium High High
Latest 100G technology exploits coherent detection together with powerful digital processing High Chromatic Dispersion and PMD tolerance Essential for long haul and fibres with high PMD Coherent performance will likely come with a higher cost
DCM-less network operation is now possible since dispersion compensation is performed within the transponders
Simplified node design with lower loss (better OSNR) Simplified fibre planning (no need to deploy DCMs) Lower latency link How to support standard 10G (non-coherent) and alien wavelengths ?
Ipswich
Bishops 57.08km Wood green 14.7km 53.6km BT Tower 58.1km 87.2km Basildon Colchester
All fibres are G.652 fibres typical of BTs optical fibre network infrastructure
All fibres are characterised (length, loss and PMD) some have very high PMD All nodes can accommodate optical amplifiers if required
British Telecommunications plc
terminal here
Ipswich
Bishops 57.08km Wood green 14.7km 53.6km BT Tower 58.1km 87.2km Basildon Colchester
410km
loopback here
Trial fibre route from Adastral Park to BT Tower 410km (round-trip) WDM terminal at Adastral Park, intermediate amplifier (and DCM) sites at Colchester, Basildon and BT Tower
British Telecommunications plc
Fibre routes are selected for the demonstration and evaluation of the 100G transmission performance
Note measurements above are for coherent link (high PMD) Other links low PMD
loopback
11.7dB 49.23km
Adastral park Colchester
optical amplifier
PMD tolerance
Using PMD emulator to add DGD
Multi-line Rate operation - co-existence of 10G/40G/100G signals Ethernet Transport Latency, throughput and jitter Application demonstration of HDTV/IPTV
Single channel optical performance in field trial over 410km from Adastral park to BT Tower (with DCM in link)
Total DGD value includes PMD from field fibre system and additional PMD generated from PMD emulator Coherent 100G has very high PMD tolerance with error free performance for DGD ~100ps
Coherent 100G and 40G have error free performance in DCM-less DWDM system
British Telecommunications plc
Tx Rx
40/100G
Tx Rx
Tx Rx
To Tester
Summary
We have successfully demonstrated operation of ??????G over BT 21CN infrastructure designed for 10G
Mixing technologies Stable long term operation
Coherent is powerful and the choice for ultimate performance and reach
High PMD tolerance means that poor fibre links can be utilised, optimising asset usage
Enables new DCM-less network operation with simpler planning and design, enhanced OSNR performance
But support for conventional 10G and alien waves needs to be considered
Acknowledgements
BT Team: Yu-Rong Zhou, Kevin Smith, Mark Wilkinson, Paul Wright