Looking to optimize applications such as virtual reality and online gaming, CableLabs has quietly released an annex to DOCSIS 3.1 that can support sub-1 millisecond latencies.

According to CableLabs, existing DOCSIS 3.1 equipment will be able to support low-latency DOCSIS (LLD) with just a software upgrade.

"Although VR is still struggling to gain widespread adoption, that low and reliable DOCSIS latency will be a boon to gamers in the short term and will enable split renderings of VR and augmented reality (AR) in the longer term," Steve Glennon, distinguished technologist of the Advanced Technology Group at CableLabs, explained in this blog item posted Thursday about the relatively new capability.

A CableLabs official said LLD was included in an update to D3.1 (for the MAC and upper layer protocols interface portion of the spec) in January and has been updated since, most recently in April.

Low-latency gaming is already being eyed as a potential broadband service enhancement and potential new revenue driver. Cox Communications, for example, is testing a low-latency gaming tier for PCs in Arizona that costs an extra $14.99 per month.

Low-latency DOCSIS is a component of the cable industry's broader "10G" initiative, which is focused on next-gen capabilities, such as symmetrical speeds of up to 10 Gbit/s. Although low-latency DOCSIS focuses on HFC networks, CableLabs has stressed that 10G is aimed at a wide range of access network technologies, including FTTP and wireless. Per a new "timeline" for 10G, the current version of DOCSIS 3.1 is considered version 1, with future versions -- 10Gv2 and 10Gv3 -- poised to add Full Duplex DOCSIS and low-latency capabilities, as well as the use of capacity at frequencies well above 1.2 GHz.

In a deeper dive into the LLD effort, CableLabs notes that people tend to detect delays at about 20 milliseconds. So network latency needs to be cut down to near-zero to enable real-time digital experiences and to support apps where low latencies are critical, such as VR, gaming and even telesurgery.

CableLabs says its angle with low-latency DOCSIS involves the optimization of traffic flows, giving latency-sensitive applications a higher priority without slowing down all other traffic.

CableLabs also claims that LLD can be enabled with a "cost-effective software update" (it's not talking exact costs) without "overhauling" the existing HFC network. The organization notes that DOCSIS 3.1 networks already support an Active Queue Management (AQM) feature that improves latency, but LLD aims to take that capability to a new (and lower) level.

According to Glennon, CableLabs launched its low-latency journey more than four years ago as it started to look at apps that will drive the need for sustained speeds of 60 Mbit/s and higher, leading to an examination of "immersive video content" and emerging holographic-based content.

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— Jeff Baumgartner, Senior Editor, Light Reading