Behind the numbers
CIR’s report key findings
The global market for active optical cable (AOC) is forecast to grow to US $1.5bn by 2014, with the linking of datacenter equipment being the largest single market valued at $835m. Other markets for the cabling technology include digital signage, PC interconnect and home theatre.
CIR’s report entitled Active Optical Cabling: A Technology Assessment and Market Forecast notes how AOC emerged with a jolt. Two years on and the technology is now a permanent fixture that will continue to nimbly address application as they appear. This explains why CIR views AOC as an opportunistic and tactical interconnect technology.
AOC: "Opportunistic and tactical"
Loring Wirbel
What is active optical cable?
An AOC converts an electrical interface to optical for transmission across a cable before being restored to the electrical domain. Optics are embedded as part of the cabling connectors with AOC vendors using proprietary designs. Being self-contained, AOCs have the opportunity to become a retail sale at electronics speciality stores.
A common interface for AOC is the QSFP but there are AOC products that use proprietary interfaces. Indeed the same interface need not be used at each end of the cable. Loring Wirbel, author of the CIR AOC report, mentions a MergeOptics’ design that uses a 12-channel CXP interface at one end and three 4-channel QSFP interfaces at the other. “If it gets traction, everyone will want to do it,” he says.
Origins
AOC products were launched by several vendors in 2007. Start-up Luxtera saw it as an ideal entry market for its silicon photonics technology; Finisar came out with a 10Gbps serial design; while Zarlink identified AOC as a primary market opportunity, says Wirbel.
Application markets
AOC is the latest technology targeting equipment interconnect in the data centre. Typical distances linking equipment range from 10 to 100m; 10m is where 10Gbps copper cabling starts to run out of steam while 100m and above are largely tackled by structured cabling.
“Once you get beyond 100 meters, the only AOC applications I see are outdoor signage and maybe a data centre connecting to satellite operations on a campus,” says Wirbel.
AOC is used to connect servers and storage equipment using either Infiniband or Ethernet. “Keep in mind it is not so much corporate data centres as huge dedicated data centre builds from a Google or a Facebook,” says Wirbel.
AOC’s merits include its extended reach and light weight compared to copper. Servers can require metal plates to support the sheer weight of copper cabling. The technology also competes with optical pluggable transceivers and here the battleground is cost, with active optical cabling including end transceivers and the cable all-in-one.
To date AOC is used for 10Gbps links and for double data rate (DDR) and quad data rate (QDR) Infiniband. But it is the evolution of Infiniband’s roadmap - eight data rate (EDR, 20Gbps per lane) and hexadecimal data rate (HDR, 40Gbps per lane) - as well as the advent of 100m 40 and 100 Gigabit Ethernet links with their four and ten channel designs that will drive AOC demand.
The second largest market for AOC, about $450 million by 2014, and one that surprised Wirbel, is the ‘unassuming’ digital signage.
Until now such signs displaying video have been well served by 1Gbps Ethernet links but now with screens showing live high-definition feeds and four-way split screens 10Gbps feeds are becoming the baseline. Moreover distances of 100m to 1km are common.
PC interconnect is another market where AOC is set to play a role, especially with the inclusion of a high-definition multimedia interface (HDMI) interface as standard with each netbook.
“A netbook has no local storage, using the cloud instead,” says Wirbel. Uploading video from a video camera to the server or connecting video streams to a home screen via HDMI will warrant AOC, says Wirbel.
Home theatre is the fourth emerging application for AOC though Wirbel stresses this will remain a niche application.
