Adding Upstream Capacity Carries Technical Challenges: Cable Panel

Cable operators' effort at boosting their networks' upstream capacity is driven in large part by fallout from the COVID-19 pandemic, operators and suppliers said Thursday. During an SCTE webinar, cablers said boosting upstream capacity also carries with it a variety of technical and spectrum challenges. The workplace changes the pandemic has driven, with more people working hybrid or fully remote, are pushing demand for additional upstream capacity, said Chris Topazi, Cox Communications principal architect. Also driving upstream demand is that people are increasingly prone to video chatting as opposed to phone calls, he said. Between 2020 and today, Midco saw average users' upstream usage go from 17-20 Mbps to 120-150 Mbps, said Vice President-Network Engineering Pao Lo. Competition also is a driver of upstream capacity supply, said Karthik Sundaresan, CableLabs director-hybrid fiber coaxial solutions. When cable competes in markets with fiber deployments, there often is pressure to offer higher upstream services even when actual upstream usage isn't close to what peak capacity allows, he said. Cable has multiple options for boosting upstream spectrum and capacity. DOCSIS 3.1 broadband delivery specifications can deliver up to 1 Gbps upstream, Sundaresan said. Operators' move to DOCSIS 4.0 in coming years opens the door to be closer to symmetrical service, with upstream capacity close to downstream, he said. But as operators focus on upstream, they must consider upstream "noise" problems. The noise comes from modems and active network components, as well as sources ranging from broadcast signals to wireless devices, he said. Vecima Chief Technology Officer Colin Howlett said freeing spectrum for upstream capacity might necessitate moving to internet protocol video. Lo said Midco is about 60% through an IP TV conversion. A year from now Cox will be heavily focused on field trials of DOCSIS 4.0, Topazi said.