By ITU News

Demand for higher-capacity networks keeps rising with no end in sight.

As people communicate in high-definition video and gain ever more immersive experiences with virtual reality and cloud gaming, the need for more bandwidth keeps growing. Machines, too, rely on high-speed, low-latency connectivity, especially with increasingly automated industrial processes.

The capabilities widely enjoyed today, along with those envisioned for the future, all depend on technical standards developed by the International Telecommunication Union (ITU) and its standardization arm, known as ITU-T.

ITU-T Study Group 15 defines the “networks, technologies and infrastructures for transport, access, and home.” The extent to which we rely on these standards is hard to overstate.

“We can start in your home,” says the group’s new Chairman, Glenn Parsons from Ericsson. “You may extend your Internet access in your home across your power lines, and the Internet access for your home may be provided over copper or fibre access from your service provider.”

Breaking speed and capacity records

Standards developed by Study Group 15 enable multi-gigabit broadband access. The latest standards in the access arena provide for speeds up to 8 gigabits per second (Gbit/s) over traditional telephone wires and 50 Gbit/s per wavelength for fibre to the home.

Study Group 15 standards also define the extremely high capacity ‘backbone’ transport networks that line modern cities and traverse the world’s oceans. The group’s experts modestly refer to themselves as the world’s ‘bit truckers’, building information superhighways and the vehicles travelling over them.

“Between cellular towers or between network operators, all of these connections are provided with fibre and copper transport mechanisms and protocols that we define in Study Group 15,” explains Parsons, adding: “Our standards provide the framing and rates for fibre networks, and we’re looking at moving this to towards multi-Terabit for the long haul.”

Study Group 15 helped introduce wavelength-division multiplexing, which puts multiple signals simultaneously onto a single fibre cable. It now aims to lay the foundations for the cost-effective global rollout of space-division multiplexing, which boosts optical data transmission with multiple channels.

Promising applications include submarine telecoms, another area where standards from Study Group 15 are key. “We’re looking at wavelength-division multiplexing, a common mechanism to increase the capacity on fibre, and evolving that towards space-division multiplexing.”

While always working to enable faster networking speeds, the group is just as focused on lower latency. “Lower latency is required for a lot of applications that we’re now seeing in the market, from 5G cellular to industrial automation,” says Parsons.

Starting in 2018, the study group focused on meeting the demands of emerging fifth generation (5G) mobile services on transport networks. This is an area where ITU standardization (ITU-T) and radiocommunication (ITU-R) work complement each other closely.

“Wireless is, of course, the responsibility of ITU-R, but we are fundamental to 5G networks because we provide the transport to connect all the towers together,” explains Parsons.

Enabling synchronization and fronthaul

ITU-T Study Group 15 provides for transport networks with the necessary capacity and management-control functions to support 5G. Parsons also emphasizes the importance of meeting new requirements for synchronization and mobile fronthaul.

“We have synchronization activities that support packet timing,” he says, referring to multiple ITU standards describing network synchronization for both frequency and precision time. Timing has grown in importance immeasurably with advances through 4G and 5G and is expected to become even more important in future. “Fronthaul” refers to the new latency and synchronization demands that 5G places on mobile networks.

“From a 5G perspective, backhaul is the more generalized higher bandwidth, but it’s that fronthaul – the connection directly from the antennas on the tower down to the baseband unit – that requires the lower-latency, higher bandwidth facilities that that we’re looking to provide with the physical fibre technologies in Study Group 15.”

Building consensus for the market

ITU standards are developed collaboratively – primarily by the same industry players that subsequently rely on them.

“It’s a consensus-building exercise,” says Parsons. “Companies want to make sure that the latest features that they’ve designed are included in the standard.”

“Our September meeting in Geneva was a welcome return to in-person meetings, bringing back efficiency to our work of building consensus.”

Standardization allows interoperability among vendors, reduces costs, and assures the customer of a certain level of quality and reliability.

“If you can rally the industry, the market, around a particular standard, that enables multiple vendors to compete for business based on this one standard,” he adds. “If you have one standard that we can all agree on, then that’s a benefit to the market and a benefit to the customer. It’s really a way to grow the market.”