Ribbon Communications has started working with operators to trial its latest Apollo 9408 optical transport platform that supports 1.2 terabits per second (Tbps) optical wavelengths.
The company's modular platform can also send 800 gigabit-per-second (Gbps) wavelengths over 1,000km and 400Gbps wavelengths over ultra-long-haul networks.
Jonathan Homa
"We have conducted trials, including one with a Tier 1 European provider," says Jonathan Homa, senior director of solutions marketing at Ribbon. "You can get 1.2 terabits within major cities, 800 gigabits covering major states or regions, and 400 gigabits for about as long as you want to go."
"The Apollo 9408 is Ribbon's first disaggregated transponder unit or compact modular box using the CIM 8 for up to 1.2Tbps of wavelength speed," says Jimmy Yu, vice president at market research firm Dell'Oro Group.
Yu believes the product has shipped to a customer this quarter and is likely the first commercial shipment of a 1.2Tbps wavelength system for network deployment.
Acacia's CIM 8 pluggable coherent modem
The Apollo 9408 uses Acacia's pluggable Coherent Interconnect Module (CIM 8) coherent modem. The CIM 8 uses Acacia's 5nm CMOS Jannu digital signal processor (DSP) and its silicon photonics-based coherent optics operating at a symbol rate of up to 140 gigabaud.
"The advantage of this smaller transistor geometry is not only the higher density per die but also lower power and faster processing speed," says Yu. "All the things needed to help service providers achieve cost and power efficiencies." This is why the market looks forward to the next generation of coherent DSPs, says Yu.
Acacia started shipping the CIM 8 at the year's start, and Ribbon says the module's availability enables the company to leapfrog existing 7nm CMOS-based coherent optical transport solutions.
Before 1.2 Tbps-capable wavelengths, the highest speed was 800Gbps, delivered by Ciena, Huawei, and Infinera, says Yu.
"Ciena was first to market and captured the lion's share of shipment volumes," says Yu. "We peg Ciena's market share of 800 Gbps-capable wavelengths at approximately 70 per cent of the cumulative shipments through 2Q 2023. That is a huge share, benefiting from being first to market."
Compact modular platform
The compact modular platform format was developed to meet the large-scale data centre operators' computing needs. The platform is used for data centre interconnect applications while the large communications service providers are become interested in the platform form factor.
Jimmy Yu
Compact modular platforms are 600mm deep and use front-to-back airflow for cooling. In contrast, standard telecom equipment is 300mm deep and uses a left-to-right airflow. The compact modular format thus suits data centres with alternate hot and cold aisles of equipment. The platforms face each other, so the air in a cold aisle is blown through each platform, exiting in the adjacent hot aisles. The efficient cooling scheme enables the equipment to be run hotter.
"With the compact modular platform's front and back airflow, we can run the CIM 8 to 1.2 terabits," says Homa. "In our standard [telecom] platform [the Apollo 9600 series], we're using the same CIM 8 pluggable, but from a power dissipation point of view, we can only run it to 800 gigabits."
The 9408 supports different channel plans depending on how the platform is used. For a cost-optimised transmission, a 400Gbps wavelength fits in a 75GHz channel, and a performance-optimised 800Gbps or 1.2Tbps wavelength fits in a 150GHz channel.
"With continuous baud rate control from 68-140Gbaud, the CIM 8 can accommodate any channel width such as 112.5GHz with networks that have flexible grid ROADMs [reconfigurable optical add/drop multiplexers]," says Homa. "It also uses probabilistic constellation shaping to maximise the line rate for that channel width."
Configurations
The Apollo 9408 is a two rack unit (2RU) platform. For high-performance optical transport, it holds four MPJ1200_2 sleds. The sleds slot into the compact modular platform, with each sled hosting two CIM 8 modules. The power consumption of the double CIM 8 sled is 270W or less than 0.12W/gigabit. The total transport capacity is thus 9.6 terabits.
Ribbon plans to double the CIM 8s within the 2RU capacity platform to offer 19.2 terabits of capacity.
Alternatively, the 2RU rack can hold up to four MPQ_8 sleds hosting eight 400-gigabit coherent optical modules for a total capacity of 12.8 terabits. Ribbon uses 64 gigabaud 400-gigabit QSFP-DDs that use a transmit power of 0dBm and are OpenROADM MSA compliant.
Source: Ribbon
"The MPQ_8 is also designed to accept a new generation of 124Gbaud 800Gbps QSFP-DD pluggables currently in development and expected to be available in early 2025," says Homa.
Ribbon also offers its standard telecom Apollo 9600 series platforms, from the smallest 2RU 9603 to the 5RU 9608 to the largest 15RU 9624 chassis. The Apollo 9600 modular platforms can use two CIM 8s in the TM800_2 double-slot card for performance-optimised transmission to 800 gigabits, or two CFP2-DCO modules in the TM400_2 single-card slot card for cost-optimised transmission to 400 gigabits.
Industry timing
Optical system vendors that don't develop their own coherent DSP chips or modems, such as Ribbon, have several supply options. The leading merchant DSP suppliers include Acacia, NEL and Marvell. There are also competitor optical transport providers that source their coherent modem solutions. Ribbon discussed with several coherent modem suppliers but chose Acacia's CIM 8 for the 9408. Ribbon has worked with Acacia for a decade.
The CIM 8's 5nm Jannu DSP leapfrogs the 90-100GBd 7nm CMOS generation of coherent DSPs now deployed. This year, 5nm CMOS coherent DSPs have been announced by Nokia and Infinera. Merchant suppliers NEL and Marvell have also detailed their latest coherent DSPs. All these devices operate at symbol rates in the region of 130-150GBd.
Acacia also supplies the CIM 8 to other optical transport vendors such as Cisco, Acacia's parent company, ZTE, and Adtran. Cisco has announced its Network Convergence System (NCS) 1014 compact modular platform that includes a 2.4Tbps transponder Line using the CIM 8. In March, Adtran reported sending an 800-gigabit signal over 2,200km using the CIM 8 as part of a networking trial. The route included 14 route-and-select flexible-grid ROADMs.
"It will be interesting to see the market dynamics unfold over the next year. There will be more system suppliers of 1.2 Tbps-capable wavelengths," says Dell'Oro's Yu. "Many system vendors will use the CIM 8, and some will use NEL's ExaSpeed GAIA DSP. Some will also develop in-house DSPs such as Huawei and Nokia."
Every dense wavelength division multiplexing (DWDM) system vendor will have a 1.2 Tbps-capable line card available for sale before the end of 2024, except for Ciena, says Yu: "This is because Ciena will come out with a 1.6 Tbps-capable DSP on a 3nm process node in 2024, one to two years ahead of any other vendors."
Earlier this year, Ciena announced its WaveLogic 6, the first coherent DSP that operates at 200GBd. Ciena says it will offer its optical transport systems using its 3nm CMOS coherent DSP in the second half of 2024.
Homa believes that the next jump will be 240-plus GBd coherent DSPs, likely implemented using an even smaller 2nm CMOS process node.
The OIF's 1600ZR 1.6-terabit coherent pluggable module standard will use a 240GBd symbol rate DSP.