Comcast said today that it expects to launch its latest Xfinity 10G network upgrade to 10 million homes and locations by the end of this month. The company said those locations had received “foundational network enhancements” required to begin deploying DOCSIS 4.0. When coupled with the newly completed enhancements, DOCSIS 4.0 will enable the company to support multi-gigabit symmetrical speeds.
A Comcast spokesperson confirmed that the 10 million locations are in more than 40 markets. Among the 40 markets are Atlanta, Boston, Chicago, Denver Houston, Miami, Philadephia, Salt Lake City, Seattle, San Francisco, and Washington D.C.
The company stopped short of saying it was launching 10 Gbps service. The word “10G” is a broad cable industry term for a group of initiatives aimed at eventually supporting speeds of 10 Gbps downstream and 6 Gbps upstream.
The company also stopped short of saying it has begun deploying DOCSIS 4.0. Equipment supporting DOCSIS 4.0 is not expected to be commercially available in volume until later this year.
Comcast has not detailed what its multi-gigabit symmetrical speeds will be when it deploys DOCSIS 4.0, but the company has achieved 6 Mbps downstream and 4 Gbps upstream in real world tests. Achieving speeds in that range requires not only DOCSIS 4.0 but also certain other network upgrades.
Those other network upgrades are the focus of today’s news.
Comcast 10G Network Upgrades
What Comcast means by “foundational network enhancements” and “network improvements” was laid out in September, when the company announced that it planned to upgrade its entire network to support multi-gigabit symmetrical speeds by the end of 2025.
At that time, the company noted plans for “finalizing transition to a cloud-based, virtualized network” and “a network architectural update that enables greater upload and download capacity.”
A Comcast spokesperson confirmed that the reference to the “cloud-based, virtualized network” is a reference to distributed access architecture (DAA), an essential upgrade to maximize speeds on cable company hybrid fiber coax (HFC) infrastructure.
Deploying DAA involves installing Remote PHY and/or remote MAC PHY devices in the node where optical signals are converted for transmission over coax. It also involves converting to digital optics between the headend and the node.
The reference to the “network architectural update that enables greater upload and download capacity” is a reference to Comcast’s plan to expand the amount of spectrum used within the coaxial portion of its network and to use a full-duplex approach.
Traditionally, cable companies used no more than 860 MHz of spectrum within the coax, but Comcast plans to expand that to 1.2 GHz. As it does so, it also plans to dedicate a substantial portion of that spectrum to full-duplex communications, meaning that the spectrum can support upstream or downstream communications.
Expanding the amount of spectrum that can be used for upstream communications is critical to being able to support multi-gigabit symmetrical connectivity.
The traditional HFC design dedicates substantially more spectrum within the coax to downstream communications than to upstream communications, limiting the upstream speeds that cable companies can support.
That limitation has been problematic for cable companies as customers make increasing use of upstream communications to support videoconferencing, gaming and other applications.
It’s important to note that network upgrades such as DAA and expanding coax spectrum can boost speeds on existing DOCSIS 3.1 networks, so potentially speed upgrades could be part of the launch that Comcast is planning for later this month.
The company also has talked about rolling out certain Wi-Fi enhancements this year, which also may be part of the launch news.
Additional information can be found in this press release.
Updated with information from a Comcast spokesperson