AT&T says second version of Gfast offers better powering, bandwidth capabilities


AT&T has set an aggressive plan to roll out Gfast across 22 markets outside of its wireline territory, but the service provider is already keen to take advantage of bandwidth and powering elements that are being integrated into the second generation of Gfast. It is expected that the second generation of the Gfast standard will emerge sometime in 2018. 

Today, AT&T is going to deliver asymmetrical 500/100 Mbps speeds to consumers mainly located in MDU environments.

When it migrates to the second generation of Gfast, the service provider will be able to deliver up to 1.5 Gbps over existing coax cable and copper.

“In generation 2, you get about 1.5 Gbps of throughput,” said Eric Small, VP of Commercial and MDU Solutions AT&T, in an interview with FierceTelecom. “Not that you would use more than a gig in either direction, but it gives you the flexibility to use a gig in one direction and 500 Mbps in the other direction.”

Additionally, the second generation of Gfast will enable what’s known as reverse power feeding (RPF). RPF allows sending power from the customer premises to a distribution point (DP), to power the distribution point unit (DPU).

While service provider plans will vary, there are four main powering scenarios for telcos related to Gfast deployments:  

Fiber to the curb: In this configuration, a service provider will extend fiber to a remote terminal (RT) cabinet located close to an MDU or neighborhood. Because power is already present at these locations, there is little need for RPF.

Fiber to the distribution point (FTTdp): Reverse power feed is required in most cases.

Fiber to the building: While there is generally power located when a service provider extends fiber into a building, there are situations where it is not present. In some cases, buildings units are installed on the outside of the building, meaning RPF is required.

Wireless to the rooftop (WTTR): In this scenario, there’s a mixture of local power and sometimes no local power.

Small said that the additional powering options in the second generation of Gfast will be of great value as it scales its service footprint.

“The really interesting part of the second generation of Gfast is it allows for reverse powering, which means the power could come from the individual subscribers,” Small said. “This becomes helpful depending on where we end up with FCC rules for battery backup on the network side backup.”

Michael Weissman, chairman of the Broadband Forum's Gfast Council and a co-founder and vice president of marketing for Sckipio Technologies, agreed.

“Reverse power feed (RPF) is a highly sought-after feature,” Weissman said. “It will be important for the second-generation solutions and these solutions need to be well tuned to RPF needs.”