Cisco ONS 15454 40Gbps CP-DQPSK Full C-Band Tuneable Transponder Card

Product Overview

The Cisco^® ONS 15454 Multiservice Transport Platform (MSTP) supports a 40-Gbps Full C-Band Tunable CP‑DQPSK Transponder Card, which simplifies the integration and transport of 40 Gigabit Ethernet and OC‑768/STM-256 interfaces and services into enterprises or service provider optical networks (Figure 1).

Cisco ONS 15454 MSTP Release 9.2.1 extends the overall data bandwidth that can be transported by the system with a factor of four, allowing transmission across Cisco ONS15454 MSTP dense wavelength-division multiplexing (DWDM) networks up to 3.20 Tbps over 80 wavelengths at 40 Gbps.

Challenge and Solution

The bandwidth carried on core and metropolitan (metro) DWDM networks is growing exponentially, while operators’ revenues are not growing as quickly. The Cisco ONS 15454 40 Gbps solution can dramatically lower the cost to carry bandwidth, helping to maintain and improve customers’ profitability. Internet growth is still exponential, mainly due to demand for next-generation services such as quadruple play (data, voice, video, and mobility), video distribution, Internet Protocol Television (IPTV), and other high-bandwidth services.

This growth slows transmission in DWDM networks that require technology advances to support such large bandwidth. The scale of 10 Gbps to 40 Gbps is the perfect solution for this problem; it quadruples the bandwidth that can be transported over existing fiber networks.

New modulation techniques now support ultra-long-haul (ULH) networks with more than 2000 km of unregenerated optical links. The Cisco ONS 15454 MSTP 40 Gbps Full-Band Tunable CP-DQPSK Transponder Card is designed to satisfy the following requirements.

●   40-Gbps signals must work in fully uncompensated networks up to more than 2000 km.

●   40-Gbps signals must work with very low-quality fiber with very high polarization mode dispersion (PMD) coefficients.

●   40-Gbps technology must work on 50-GHz systems with negligible filtering penalty.

●   40-Gbps units must fit mechanically and thermally with existing installed shelves with no effect on existing units, allowing full back-compatibility and no restriction rules for where the units can be placed.

●   40-Gbps units must support the widest variety of signals without impairments and with full compliance to international standards.

Product Features and Benefits

The The Cisco 40-Gbps Full-Band CP-DQPSK Transponder Card can transport SONET OC-768, SDH STM-256, optical transport network (OTN) Optical Transport Unit Level 3 (OTU3), 40 GbE WAN PHY and constant bit rate (CBR) signals at 40 GbE LAN PHY rate over a 50-GHz spaced, 50-GHz stabilized, ITU-compliant wavelength. The transponder card is a plug-in module to the Cisco ONS 15454 MSTP, providing a cost-effective architecture for delivering high-rate 40-Gbps services as well as low-rate services down to 1.5 Mbps. The transponder card architecture contains a single client interface that is mapped to a single line interface, without accessing the Cisco ONS 15454 shelf cross-connect fabric.

The client interface supports a standard VSR2000-3R2(F) SONET OC-768, SDH STM-256, OTN OTU3, 40-GbE WAN PHY, and CBR signals at 40 GbE LAN PHY rate.

The DWDM line interface provides a configurable 43.018-Gbps to 44.570-Gbps G.709 OTU3 digital wrapper, long-reach/long-haul, ITU-compliant, 50-GHz spaced optical interface using LC connectors supporting G.709 OTU3 digital wrapper interfaces. The DWDM output line interface is tuneable across the full optical C band, dramatically reducing inventories for spares. When operated within the outlined specifications, each card will transport the 40-Gbps signals with a maximum bit error rate (BER) of 10E-15.

The Cisco 40 Gbps Full-Band Tuneable CP-DQPSK Transponder Card provides many carrier-class features and advanced capabilities necessary to deliver 40-Gbps services, including protocol transparency, wavelength tuneability, flexible protection mechanisms, flow-through timing, and management and performance monitoring capabilities (Figure 2).

Enhanced FEC Capability

The card can support a forward error correction mechanism on trunk and client interfaces.

The trunk port supports FEC and enhanced FEC (EFEC); you cannot disable such mechanisms. The output bit rate does not depend on the selected algorithm, but you can provision the error coding performance.

●   FEC: Standard G.975 Reed-Salomon algorithm

●   EFEC: Standard G.975.1 (Subclause I.7); two orthogonally concatenated BCH super FEC code. This FEC scheme contains three parameterizations of the same scheme of two orthogonally interleaved block codes (BCH). The constructed code is decoded iteratively to achieve the expected performance. EFEC provides 2 to 3 dB of additional reach compared to standard FEC pending OH redundancy (10 percent to 13 percent).

The client port supports an FED mechanism that you can disable:

●   FEC: Standard G.975 Reed-Salomon algorithm

Advanced Modulation Scheme

Cisco 40 Gbps Full-Band Tunable CP-DQPSK Transponders feature an advanced modulation scheme that aims to reach performance beyond industry-standard 10-Gbps equivalent units.

Cisco selected a Coherent Polarization Differential Quadrature Phase Shift Keying (CP-DQPSK) modulation format to optimize 40-Gbps Transmission in terms of optical signal-to-noise ratio (OSNR), chromatic dispersion robustness, and PMD robustness.

The CP-DQPSK modulation scheme consists of multiplexing two DQPSK signals over two different orthogonal polarizations, as shown in Figures 3 and 4.

The core of the 40-Gbps PM DQPSK modulation scheme is the receiver that is based on coherent detection, where a digital signal processor (DSP) calculates the inverse of the optical system matrix, allowing the receiver to recover the original transmitted signals (Figure 5).

The main benefits of CP-DQPSK are:

●   Strong OSNR performance (better than 10-Gbps units)

●   Outstanding chromatic dispersion robustness for performance in a completely uncompensated network

●   Very strong PMD robustness (three times better than 10-Gbps units)

●   Very good spectral density that allows traffic to cross a long cascade of reconfigurable optical ad-drop multiplexers (ROADMs) with negligible penalty

Transponder Card Versions

Two versions of the Cisco 40-Gbps Full-Band Tunable CP-DQPSK Transponder Cards are offered to support different application requirements:

●   An extended performance version offering full performances targeting ULH application, where the network is optimized for CP-DQPSK transmission (no 10-Gbps channels and Dispersion Compensation Units [DCUs])

●   A metro edge performance version with differential mode only (CP-DQPSK), cost-optimized for metro application and 10-Gbps installed networks

Protocol Transparency and Card Configuration

The Cisco 40-Gbps Full-Band Tuneable CP-DQPSK Transponder can deliver transparently any 40-Gbps services for cost-effective, point-to-point networking for the Cisco ONS 15454 platform.

The card can be provisioned in two operational modes: OTU3 or OTU3e.

In OTU3 mode, the card can transparently transport STM-256, OC-768 40 GbE WAN-PHY signals. In OTU3e mode, to the card can transparently transport a 40 GbE LAN PHY Constant Bit Rate (CBR) signal on a serial interface, as shown in Table 1.

Table 1.       Transponder Client Configurations and Mapping

 

The card can also process provisionable SONET/SDH overhead bytes. It is possible to pass the bytes transparently or to terminate the line and section overhead. In transparent mode, client terminal equipment interconnected over a transponder-based circuit can communicate over the section (or multiplexer section) data communications channel (SDCC/MSDCC), can signal 1+1 and bidirectional line switched ring or multiplex section-shared protection ring (BLSR/MS-SPR) protection switching using the K1 and K2 bytes, and can support provisionable section trace capabilities over the J0 byte.

In addition, the transponder circuit, whether provisioned in transparent or terminating mode, can support client circuits based on unidirectional-path switched ring (UPSR) or subnetwork connection protection (SNCP). The transponder card is transparent to the embedded payload and does not access the Cisco ONS 15454 platform’s cross-connection. It can carry any type of concatenated SONET/SDH payloads (STS-Nc or VC-4-Mc), or nonconcatenated payloads on an STS-1, VC-4, VC-3, VC-12, or VT1.5 basis.

Wavelength Tuneability

The transponder card operates on the 50-GHz ITU grid and it is tuneable across the full C-band, on 50-GHz channels. Tuneability reduces the customer’s inventory required to cover all of the wavelengths for deployment and spares. Tuneability is software-provisionable.

Flexible Protection Mechanism Support

You can deploy the 40-Gbps Full-Band Tunable CP-DQPSK Transponder card, depending on your network requirements, to support the many protection mechanisms found in optical transport networks. Table 2 outlines the supported protection options that help to deliver the service-level agreements (SLAs) required by the application.

Table 2.       Protection Formats

Flow-Through Timing

The transponder card allows the timing to flow through from client to line optical interfaces. The receive timing from one interface (client or line) is used to time the other transmitter interface (line or client). This flow-through timing allows the transported signal to remain independent of the node timing.

Management

The Cisco ONS 15454 MSTP provides comprehensive management capabilities to support the operations, administration, monitoring, and provisioning (OAM&P) capabilities through the integrated Cisco Transport Controller craft interface with support from the Cisco Transport Manager element management system. The 40-Gbps Full-Band Tunable CP-DQPSK Transponder Card incorporates provisionable digital wrapper (G.709) functions, providing per-wavelength performance management capabilities, especially for services transported transparently across the network. Without the digital-wrapper functions, a carrier transporting a service transparently would be unable to identify network impairments that may degrade the transported signal and exceed SLA requirements. The digital wrapper’s generic communication channel (GCC) provides a separate communications channel on a per-wavelength basis, other than the SDCC or regenerator SDCC (RSDCC) in SONET/SDH signals, to be used by the platform when transparent signals are transported. This GCC allows the Cisco ONS 15454 system to extend its advanced network autodiscovery capabilities to DWDM-based services. The integrated Cisco ONS 15454 Transport Controller craft manager and the Cisco Transport Manager provide the user with OAM&P access for the system.

Far-End-Laser-Off Behavior

The Cisco 40-Gbps Full-Band Tunable CP-DQPSK Transponder Card can provision the far-end-laser-off behavior in case of ONSET/SDH payloads. Customers can use the Cisco Transport Controller to configure how the remote client interface will behave following a fault condition. It is possible to configure the remote client to squelch or to send an alarm indication signal (AIS).

For data signals (40 GbE CBR), the behavior is squelching.

Performance Monitoring

The performance monitoring capabilities of the transponder card provide support for both transparent and nontransparent signal transport. For SONET/SDH signals, standard performance monitoring, threshold-crossing conditions, and alarms are supported per Telcordia GR-253, GR-474, and GR‑2918; ITU G.828; and ETS 300 417-1 standards. The digital wrapper channel is monitored per G.709 (OTN), G.8021. Optical parameters on the client and DWDM line interfaces support loss of signal (LOS), laser bias current, transmit optical power, and receive optical power. Calculation and accumulation of the performance-monitoring data are in 15-minute and 24-hour intervals as per G.7710.

A detailed list of performance monitors is given in Table 8.

The transponder card incorporates faceplate-mounted LEDs to provide a quick visual check of the operational status of the card. An orange circle is printed on the faceplate, indicating the shelf slot in which you can install the card.

Regenerator Configuration

The Cisco 40-Gbps Full-Band Tunable CP-DQPSK Transponder Card supports the OTU3 Regeneration function. You can configure two cards to work in back-to-back mode, allowing the transponder to perform the OTN O-E-O regeneration function as depicted in Figure 6.

The client can be OC768, STM-256, or OTU3. Regeneration is performed through the OTU3 client-to-client interconnection, where OTU3 overhead is terminated, allowing ODU3 to transparently pass through. GCC0 are properly terminated, and GCC1 and GCC2 are properly passed through.

In case of failure on one side, ODUk-AIS is generated and propagated and an OTUk-BDI is sent back as defined by the ITU G.709 standard.

Application Description

The Cisco ONS 15454 MSTP 40-Gbps Full-Band Tunable CP-DQPSK Transponder Card adds the capability to cost-effectively transport 40-Gbps services. Two main applications are expected.

●   40-Gbps router interconnection for business services and research networks: Cisco research indicates that the total volume of worldwide IP traffic is doubling every two years, requiring an increase in transfer rate from 10 Gbps to 40 Gbps. The transponder solution aims to provide DWDM interconnection between 40-Gbps interfaces among routers across DWDM metro, regional, or long-haul networks. The advanced modulation scheme is designed to cope with long-distance application performance requirements, allowing the extension of 40-Gbps service over 1500 km.

●   OTU3 links in national carrier backbone networks: OTN technology is vital to backbone carrier networks. It is the baseline method that offers intercarrier or interdomain transfer to any next-generation transport network at 2.5-Gbps (OTU1), 10-Gbps (OTU2), or 40-Gbps (OTU3) rates. The Cisco 40-Gbps Full-Band Tunable CP-DQPSK Transponder supports a fully standard OTU3 interface that can cope with signals from any G.709-based OTU3 interface from an OTN cross-connection, a 40-Gbps router Interface, or other 40-Gbps transponder interfaces.

Product Specifications

Compact Design

●   Double-width card slot design for high-density, 40-Gbps solutions

●   Up to 6 transponder cards per shelf assembly supports up to 24 40-Gbps interfaces per bay frame

Flexible Restoration Options

●   Transparent support for UPSR/SNCP, BLSR/MSP, and 1+1 APS/MSP

●   Client Y-protection

●   OCH-trail protection through PSM

●   Unprotected (0+1)

Tables 3 and 4 list the regulatory compliance and system requirements for the transponder card. Table 5 lists the client-side specifications, Table 6 provides the DWDM specifications, Table 7 provides DWDM receive-side optical performance information, Table 8 gives performance-monitoring parameters, Table 9 gives card specifications, and Table 10 gives ordering information for the card.

Regulatory Compliance

Note that all compliance documentation may not be completed at the time of product release. Please check with your Cisco sales representative for countries other than Canada, the United States, and the European Union.

Table 3.       Regulatory Compliance

Table 4.       System Requirements

Table 5.       Client Side Specifications

1. Fiber distance of <FD_smf28>km in SMF28 of equivalent <SR_olb>dB optical link budget. Assumes D₁₅₅₀ = 17ps/nm/km, D₁₃₁₀ = 3.3 ps/nm/km; fiber+splice+connector loss at 1550 nm = 0.275 dB/km and 1310 nm = 0.55 dB/km; includes <P^o>dB dispersion penalty at <D_{LRlong-reachmax}>ps.

2. A receiver in compliance with application VSR2000-3R2(F) will operate in either of the application codes VSR2000-3R3 or VSR2000-3R5. It will also operate in the application code VSR2000‑3R1 if its operating wavelength range includes 1290-1330 nm.

3. A receiver in compliance with this application is required to operate in any of the application codes VSR2000-3R1, VSR2000-3R3 or VSR2000-3R5. It shall, as a minimum, operate over the wavelength range of 1290-1330 nm as well as the range 1530-1565 nm.

4. The BER for this application is required to be met only after the error correction (if used) has been applied. The BER at the input of the FEC decoder can, therefore, be significantly higher than 10–12.

5. This application can also be used on G.653 and G.655 fiber.

6. If passive optical devices in the main optical path introduce additional chromatic dispersion, the achievable link distance may be reduced. Alternatively, an application with a higher chromatic dispersion tolerance may be used to overcome this restriction.

7. The method used to verify this penalty is ffs.

Table 6.       DWDM Specifications

Table 7.       DWDM Receive-Side Optical Performances

Table 8.       Performance Monitoring Parameters

Table 9.       Card Specifications

1. Short-term refers to a period of not more than 96 consecutive hours and a total of not more than 15 days in 1 year (a total of 360 hours in any given year, but no more than 15 occurrences during that 1-year period). The values shown are valid for M6 or M2 chassis. M12 chassis will support maximum of 50ºC.

Table 10.     Ordering Information

For More Information

For more information about the ONS15454 MSTP, visit http://www.cisco.com/en/US/products/hw/optical/ps2006/ps5320/index.html.