Feeding power starved modems and taking DOCSIS upstream to a gigabit per second highlighted the “Capacity for Change: Capacity Expansion in Theory and Practice” session during the cable show’s spring technical forum.

Finding the right solution and cost to accomplish both are a work in progress, panelists agreed, but there is movement.

“The stage is being set to accommodate upstream service growth. And there is opportunity for 128- and 256 QAM to grow,” said panelist Robert Thompson, principal staff engineer for Motorola, Inc.

With the growing appetite for upstream bandwidth, Cisco’s CMTS chief architect, John Chapman, unveiled a solution that includes a low-split to top-split approach, with the end game being above 1 gigabit.

“We’ll be seeing hundreds of megabits per second in downstream, but there’s a shortage of bandwidth in upstream. Ultimately, more bandwidth is needed. But what’s the right solution and cost?” he said.

For panelist Dave Urban, a distinguished engineer for Comcast, the upstream capacity issue is real, and high on the company’s radar screen.

“We’re looking at techniques to get more capacity upstream and lessen upstream interference to digital video scenarios. Capacity upstream is a real problem,” he admitted.

WiMax could be the beneficiary of increased upstream capacity, suggested Ayham Al-Banna, staff systems architect for Arris.

“WiMax is a good candidate to support future networks because of flexible channel widths, security and QoS. But we need new resources for upstream capacity.”

He also detailed a promising solution to add power to existing cable modems. “Dynamic steering of power-starved CMS, DSG, STBs and MTAs through DOCSIS 3.0 and channel bonding and linking WiMax to HFC networks will allow more bandwidth.”