Downstream Data Demand Shows Signs of Slowing

DENVER — Though 1 Gigabit per second is the new billboard speed for broadband, the growth rate in downstream data speeds shows signs of slowing, though the precise reasons why have yet to be pinpointed.

That’s according to several top cable engineering executives who spoke at the SCTE•ISBE Rocky Mountain Chapter’s annual “Tech Exec It Out” panel. The panel followed the daylong Tech It Out conference held Nov. 16 by the Women in Cable Telecommunications (WICT) Rocky Mountain chapter.

Downstream data speeds had been getting about 50% faster per year, but that number has dropped to about 40% in some cases, panelists said in a session moderated by Leslie Ellis, president of Ellis Edits and Multichannel News technology columnist.

That trend suggests that downstream demand is shifting from exponential growth to linear growth, Tom Cloonan, chief technology officer of network solutions at Arris, said.

Building in Growth Potential
Matt Petersen, vice president of access architecture at Charter Communications, said the MSO is seeing a slight decrease in downstream demand. Nevertheless, Charter is pushing ahead with plans to roll out DOCSIS 3.1. Even if downstream data demands have begun to drop, though, the current pace of growth isn’t weak by any stretch.

“Forty percent is not slow,” Cloonan said, predicting that the industry’s hybrid fiber/coax networks will be equipped to deliver speeds of 10 Gbps in the 2020s.

Jorge Salinger, vice president of access architecture at Comcast, said data demands have ebbed and flowed before. “We’ve seen this time and time again,” he said.

Downstream trends aside, the industry is starting to key on new technologies and techniques that can help MSOs drive more capacity into the upstream. A big part of that centers on Full Duplex DOCSIS (FDX), an emerging CableLabs spec that envisions multi-gigabit symmetrical speeds.

The industry is making progress with FDX. CableLabs issued the physical layer specs for Full Duplex DOCSIS last month, a milestone that gives suppliers what they need to push ahead more rapidly with product development.

Related: Full Duplex DOCSIS Plows Ahead

“Gigabit in the upstream is an important addition,” Salinger said. Demand for upstream data isn’t being led so much by consumer activity as by machine-to-machine communications — such as cameras that record 24 hours a day, store content locally and then transmit that data upstream — and the all-encompassing Internet of Things.

“It’s something we can’t ignore,” Bill Warga, vice president of technology for Liberty Global, said.

Knittle said CableLabs is preparing to start interoperability tests of FDX-based nodes in Q1 of 2018, and the current plan is to be ready for full-on testing by the start of 2019. The timing is gauged on the availability of silicon, he said. “But it’s all starting right now.”

Pivoting to ‘Remote PHY’
Also underway is a pivot to more distributed, “remote PHY” architectures that place more electronics at the edge of the network and can bring more fidelity and capacity to the network while also relieving power and space requirements at the headend. “The node is getting smarter,” Warga said.

Distributed architectures will also enable cable operators to virtualize the network, and put more functions in software and lessen the reliance on purpose-built hardware.