We need to talk about G.fast. Or rather, we need to talk about the way we’ve been talking about G.fast.
It seems to me that operators do not always consider the advantages of G.fast, a state-of-the-art fixed access technology using twisted-pair or coax cables, when designing fiber-to-the-home (FTTH) networks. Maybe the industry hasn’t helped itself here – perhaps G.fast could have, and should have, been positioned a little differently.
Now is the perfect time to reframe the conversation: G.fast has really found its perfect use case, perhaps even what it was born to do. It addresses major pain points in FTTH rollouts because it’s a technology that extends the reach of fiber.
Before we delve in to this further, let’s take a step back a moment and look at the bigger picture.
Accelerating fiber deployments
The world is going gigabit. Whether it’s FTTH or 5G mobile, we’re entering an era of enhanced connectivity and enhanced bandwidth, everywhere we go. Customers are demanding it, regulators are mandating it, and operators are doing their absolute best to deliver it.
It is fiber that first brought gigabit to the home, creating a unique differentiator for operators that deploy it. The number of subscribers served by fiber access is increasing in each region of the world. In North America in the last 6 years, that figure has grown by 142%.1 Everyone agrees that the desired end goal of service providers is connecting everyone with fiber in their service areas, not just passing them. Most also agree that it will take quite a bit of time—and quite a lot of money—to get there. The operators tasked with deploying fiber are, of course, commercially minded businesses; the deployments they are going to prioritize are, logically, the ones where the commercial payback is quickest.
This means certain areas are at risk of being left behind – those where it is physically, technically, or administratively challenging to take fiber to every property in a service area. In these scenarios, not only is the payback at risk, but the operator leaves a portion of customers underserved, increasing the likelihood of churn and leaving the door ajar to competitors. To make a compelling case, operators need to connect every property. But how?
This is where G.fast plays an absolutely critical role.
Operators can run fiber to most premises in a deployment and use G.fast where fiber is not possible or not practical. They can provide the same service levels— symmetrical gigabit bandwidth and low latency—for both FTTH and G.fast connections. 100% service coverage is a powerful argument to use with regulators demanding fiber as it surpasses their requirements. 100% service coverage is also an invaluable marketing tool for operators. Higher bandwidth leads directly to increased ARPU through premium services, further accelerates ROI, and protects the installed base.
So when we view G.fast like this, as a way to de-risk investment, it’s clear that G.fast is a powerful enabler of fiber deployments. And it’s this precise use case that sees market forecasts for G.fast ports growing to about 2.6 million by 2025; in North America the forecasted growth rate is above 20% in the period from 2018 to 2025.2
Why G.fast?
Let’s take a typical urban environment as an example use case, which is often the priority area for fiber deployments. There are likely to be many apartment buildings and other types of multiple dwelling units (MDU). It’s often hard to get permits to replace internal wiring with fiber in these buildings, and subscribers can also be reluctant to let technicians into their homes. In addition to MDUs, G.fast offers deployment flexibility in other cases like for row houses where twisted-pair connections to a manhole are available and a sealed G.fast distribution point unit (DPU) can connect to the fiber network.
In fact, G.fast is an option in any cases where twisted-pair or coax is available but fiber drops are, for whatever reason, not feasible. Nokia’s operator customers are indicating that, in urban areas, up to 20% of premises present a challenge for a full FTTH connection. That’s a lot of subscribers going underserved and a potential hammer blow to ROI.
The options for plugging these coverage gaps are to use existing twisted-pair or point-to-point coaxial cabling or add a fixed wireless access (FWA) technology. Each has their advantages and disadvantages but crucial factors in favor of G.fast are that work permits can usually be avoided, the impact on the fiber plant and OSS is minimal, and customers can usually self-install their new service.
In these circumstances, G.fast becomes a de facto fiber technology.
- G.fast offers the same downstream sustained rates by avoiding overbooking on the passive optical network (PON) by using the same split ratio for G.fast ports on a DPU as there would be on an ONT.
- G.fast introduces less than 1 ms latency in the downstream.
- G.fast is proven in the field; customers get the same quality of experience as with GPON.
- G.fast and GPON service configuration is identical.
- G.fast DPUs can easily be integrated into any OSS environment.
MDUs are a particular sweet spot for G.fast deployments, especially if a DSLAM already exists on the premises. But G.fast can and should be considered for many places where a twisted-pair exists. Using the 212-MHz G.fast profile enables operators to deliver gigabit broadband up to 150 m. Premium services of hundreds of megabits per second can be provided with up to 300 m of twisted-pair.
Firstly, G.fast DPUs typically have GPON or XGS-PON uplinks, and other uplink technologies like point-to-point fiber, Gigabit Ethernet, or 10 Gigabit Ethernet can also be supported. G.fast DPUs come in a wide variety of form factors, from 4 to 96 subscriber ports in indoor, outdoor, and hardened outdoor variations. Reverse power feeding (RPF) is an important feature of G.fast. RPF enables the DPU to draw power from end-users, meaning operators can install a G.fast DPU even in a location without a local power source.
When it comes to service configurations for quality of service and bandwidth parameters, they’re identical for G.fast and PON connections. This operational simplification mustn’t be underestimated as it removes another barrier to deployment. G.fast platforms also are available that leverage cloud networking to further simplify operations. G.fast systems also are on that market that are compatible with zero touch provisioning, which eliminates the need for technician site visits. Such DPUs are pre-provisioned in the cloud-deployed access network controller so that, once they’re installed, powered up, and connected to the network, the DPU is automatically identified, provisioned, and ready to go.
G.fast around the world
Commercial G.fast deployments are increasing all the time, which gives us some good examples we can replicate elsewhere. For example, the Japanese model tends to be a rack-mounted DPU in the basement with backwards compatibility enabling a graceful service upgrade by simply swapping the CPE. In Germany, we’re seeing sealed DPUs deployed in basements with RPF keeping costs down. And in Australia, four-port DPUs with RPF, with seamless switchover from existing PSTN connection to G.fast service, are being deployed.
So it really is time we changed the conversation with regards to G.fast. It’s a fiber enabler, a fiber extension, with a vital role in bringing full-fiber, gigabit connectivity, to more people, more quickly.
Maybe we should even change its name. G.fiber, anyone?
References
1. OMDIA, Total Fixed Broadband Subscription and Revenue Forecast: 2020-25 (June 2020).
2. OMDIA, Wireline Broadband Access Equipment Forecast (PON, xDSL + Gfast): 2019–25 (February 2020).
Zsolt Adamy is product marketing manager at Nokia Fixed Networks, responsible for FTTx product marketing.