Bjarke Skjoldstrup Project Manager, TDC A/S, Denmark Business Potentials and Practical Operational Aspects of Alien Wavelength Services TNC16, 12-16 June 2016, Prague, Czech Republic Bjarke Skjoldstrup Project Manager, TDC A/S, Denmark Calibration of the size of the window for the presentation notes --

Concept behind use of Alien Wavelengths in the TDC network Router-to-router transmission Relevant scenario: Capacity and reach demands equal the maximum achievable per wavelength in the optical network Transport Network Router A Router B 100G grey interface Optical Network 100G coherent interface Traditional POP solution: Engine Interface Transponder Multiplexer Router A OTN node 100G coherent interface Optical Network POP solution using Alien Wavelength: Engine Interface Besides bringing the cost down AW simplifies the network AW is the preferred method used for transport in the IP/MPLS core network of TDC Multiplexer Router A OTN node

Current use of Alien Wavelengths in TDCs network TDCs IP/MPLS core network 100 Gbit/s Alien Wavelengths 21 Alien Wavelength trails OTN managed OCh trails OCh termination divided between two vendors Physical path: 14-1.019 km 100G links with AW using PM QPSK modulation and SD FEC. Our experience in TDC is that the AWs are easy to operate within the company. We have found that the organisational structure is important for facilitating the use of AWs. Based on “TDCs new IP Core, 2015: Introducing 100G interfaces and Alien Wavelengths” Martin Skafte, TDC A/S From TDC meeting 12th of June, 2015

Interworking in the organizational structure (traditional workflow) Routing Transport Operation ODNB ODND Capacity Planning OTKI OTKI System Planning OTVB OTVB Optical Network Engine Interface Transponder Multiplexer Router A OTN node Workflow is traditionally organized by using a line structure with boundaries defined by the interfaces of the technological platforms. Great structure if the network functionallity to be managed is clearly confined within the platforms. Well-defined demarcation between departments responsibilities (defined by the physical network) Clear processes for how things are done Flexibility is a soft spot in this structure

Cross-functional teamwork (Alien Wavelengths) Routing Transport Optical power level alarms Re-tuning of VOAs Operation ODNB ODND Capacity Planning OTKI WSS pixel adjustments OA gain tilt adjustments System Planning OTVB Change of optical TX power Optical Network Optical Network Engine Interface Multiplexer Router A OTN node When AW are provided from outside the Transport platform the line organisation is challenged. The actions on the Routing or the Transport side can have crucial implication on the performance of the other. Each individual staff member need to have a more detailed knowledge of the other platform when using AW. As an example: the maintenance procedure for the optical interface … In general an excellent team work is required between the responsible for the AW source and the responsible for the host Transport network. Excellent teamwork experience – but no clear demarcation point for responsibilities Assistance across the organizational borders is required Very few TelCos have successfully done this

Work flow comparison example IP/MPLS link capacity expansion or new deployment Allocation of the responsibility of specific process steps Task\Organisation Traditional Alien Wavelength Routing Transport Identification of demand Link interface Transport path ● (trigger) (resources) Analysis & design of transport path Upgrade and configuration of AW has an impact on many parts of the organisation. … In the Traditional configuration the Routing department focus on upgrading the grey interface in the routers, and the Transport department focus on providing the required capacity for the transport path. The AW configuration offloads the Transport department by moving the responsibility for the end-to-end design and implementation of the path to the Routing department. In general the main work flow change by introducing the AW is a move of the responsibility from the Transport organisation to the owner of the Alien wavelength in the Routing organisation.

Monitoring of Alien Wavelength trail performance For each ROADM along the OCh trail: Optical line receive power Optical line transmit power Optical signal-to-noise ratio on line receive port Optical signal-to-noise ratio on line transmit port For each termination point of the OCh trail: Router interface up/down Traffic load in/out via the interface BER before and after FEC Optical input and output power Estimated cromatic dispersion Q-value and Electrical Signal-to-Noise Ratio A major issue for the operation of the AW in the Transport department is the reduction in the service and network performance management of the full trail. The full trail information is made available for the Transport department in TDC, by extracting the relevant data from the Routing management system and presenting it on a web interface to the operator of the Transport network. Brings the operation of the AW in TDC on par with the native wavelengths of the host network in the Transport department. Sufficient solution for supporting the fault and maintenance procedures … the basic operational foundation for creating a managed AW service is not complicated.

Alien Wavelength as a commercial service offer from TDC 100G coherent Alien Wavelength service evolution time line Introduction of OTN network Host network support Technical Launch  2006 Early 2015 2015 Commercial ? From a technological and operational point of view 100G AWs based on coherent technology can without any major efforts be offered to end customers as a new low cost type of transparent transport service. The time line … We are currently collecting experience from the operation in order to develop the technology to become a commercial product. Lack of a common reference for how to specify an AW service – and also the lack of interest from the market currently. But for now we can list a number of factors which influence the business potential.

Alien Wavelengths – pros and cons for commercial use Significant cost reduction for the operator Fewer components Less complicated upgrade procedures for the equipment Improved data transmission integrity for the customer New type of service offering in the Whole Sale market Cons Significant cost increase of customers interface Co-location required Customer/Operator Trail management split Cannibalization of current service offerings AW agreement impact the physical network planning Customer responsible for data performance Customer behavior may impact other services Cost and the simplicity. Improvement of the integrity between the end terminals. Facilitates proactive fault management by the customer. The customer need to invest in a more advanced optical line interface. Optical power requirement between the host and the AW equipment dictates that the equipment must be co-located. AW service is moving requests from the existing broadband services rather than creating new demands. Agreement on how to handle the shared customer-operator responsibility for ensuring the performance of the customers service as well as the performance of the operators network. AW service is strongly dependend on the specific physical parameters for the particular demand and therefore it is not straight forward to introduce an AW service and to sell it off the shelf …

PM BPSK, PM QPSK and PM DQPSK It is not straight forward for the operator: Key parameters for an Alien Wavelength Service Agreement The host network operator should as minimum disclose data like these Parameter Unit Value Wavelength range accepted (50 GHz ITU-T grid) THz 192.1 – 196.1 Modulation format accepted - PM BPSK, PM QPSK and PM DQPSK Input Power range accepted dBm -5.0 – 0.0 Output Power range delivered -16.0 – 0.0 Site A Stockholm Site B Malmö Length of the wavelength path km 812.6 Transmission fiber type ITU-T G 652 Launch power per wavelength +1.0 Number of ROADM sites in the wavelength path 6 Optical Bandwidth of each ROADM (Gaussian, -1 dB) nm 0.2 Chromatic Dispersion of the wavelength path ps/nm 12,654 – 15,288 Mean Differential Group Delay of wavelength path ps 3.6 Optical Signal to Noise Ratio of received signal dB >21.8 The technical challenge can be illustrated by the set of key parameters which should be part of a Service Specification and a Service Level Agreement for an AW service type. The operator must disclose data for the optical network segment in question to make it possible for the customer to evaluate the transparancy and performance of the AW transport. Some of these parameters are usually considered business sensitive and many operators may find it difficult to disclose these network details to the customer, which may be a competing operator in the Whole Sale marked.

It is not straight forward for the customer: Key parameters for an Alien Wavelength Service Agreement The Alien Wavelength customer should as a minimum specify data like these: Parameter Class Unit Value Transmitter launch power range Mandatory dBm Receiver input power range Minimum (at given dispersion and OSNR tolerance values) Maximum allowable Line Rate  Gbit/s Modulation format  - Transmitter Side-Mode Suppression Ratio (30-300 GHz from carrier) dB Differential Group Delay tolerance, maximum Optional ps Polarisation Dependent Loss tolerance, maximum Bandwidth of Optical Passband centered on ITU grid Minimum and maximum tolerable GHz Wavelength Excursion off ITU grid, maximum tolerable pm Manufacturer and the model/type of the Wavelength source/sink   The customer should disclose data for the parameters which characterize the AW in the optical network. The AW service requires an openness between the operator and the customer which for many reasons is uncommon in the existing Whole Sale marked. It also requires unusual commitments from both parties with respect to maintenance and fault management.

Current status is … 100G coherent AW are easy to operate inside the company A flexible organisation is required The technological foundation for operating an Alien Wavelength service is simple to establish Converting the Alien Wavelength technology to a service offered to external customers is a serious challenge The main issues are non-technical Involves unusual commitments from the customer and the operator regarding maintenance and fault management Lack of standardization and support from a number of transport system vendors has hindered a technology push Alien Wavelengths offered as a commerciel service will need a market pull to become a reality for an operator as TDC