Checking connectors: is it necessary during FTTH activation?
In recent years, the deployment of fiber-to-the-home (FTTH) networks has skyrocketed across the globe, underlining the critical attention that must be given to the health of network components—especially optical connectors—during the activation phase.
FTTH applications in today’s context
One diverging aspect of FTTH service activation is that the requirements around connector inspection do not seem as stringent as those in central offices or the data center space. This stems from the type of connections involved (e.g., multi-hundred-gigabit connections in a central office) and from the nature and number of applications served by these two distinct areas in telecommunication.
Central offices and data centers must meet very strict service-level agreements (SLAs) in terms of high availability and ultra-low latency. These SLAs guarantee a high level of uptime and performance because data centers service many critical applications such as remote surgery, self-driving cars, financial services, cloud hosting and computing, AI, etc.
In the case of FTTH, the applications are mostly centered around entertainment (e.g., a wide range of over-the-top or OTT services, gaming), smart homes or remote work. Though these applications are not as critical in comparison, they are nevertheless core to our daily lives, especially teleworking and the growing array of connected devices at home.
From the infrastructure and application perspective, we can understand that requirements relating to connector health may differ. “Good enough” connector health that might do for FTTH will be systematically failed by fiber inspection designed around central office and data center needs. However, we can also observe that in today’s current context (i.e., working from home and the popularity of streaming services), FTTH applications also tend to be bandwidth hungry while necessitating strong reliability.
So, what gives? To inspect or not to inspect? Let’s see in the next section what happens when we don’t inspect.
Most common cause of network failures: faulty connectors
It’s a well-documented fact in the industry, but always worth reminding: the leading cause of network failure is still dirty or damaged connectors1.
Optical connectors are the Achilles’ heel of fiber-optic networks. They interlink the FTTH mesh while being, prior to mating during installation and activation, vulnerable to a wide variety of contaminants. These include dust, dirt, isopropyl alcohol, oil or lotion from hands, mineral oils, index matching gel, epoxy resin, oil-based black ink and gypsum2. When it comes to connector endfaces, even micron-sized impurities can lead to signal loss as light gets reflected and poorly transmitted, if at all. Connector contamination can thus severely impact signal transmission with degradations that cascade into network issues, ultimately impacting subscriber experience.
The importance of cleaning connectors prior to mating is thus not just a technical requirement but the keystone of best practices for ensuring the high-speed, reliable internet service that FTTH networks promise.
There’s no way around connector inspection in today’s context where high-speed broadband is considered an essential service. However, that does not mean to say that the same type of connector inspection should apply everywhere in the network, from cloud-hosting up to customer premises.
What about connector inspection that’s adapted for FTTH?
Clean connectors matter. But the level of cleanliness may vary. Connectors in strategic locations where fiber runs dense and deep must be spic and span as per industry standards (e.g., IEC, TIA) that ensure strict SLAs are met, but connectors in last-mile FTTH just have to be clean enough.
This is an important distinction as the more a connector gets handled, the more likely it is of becoming contaminated. In other words, if the FTTH connection is good enough there is no point in trying to meet standards designed for data centers and run the risk of actual contamination that will put the signal quality in jeopardy.
Technicians activating FTTH services need a way to inspect connectors that is adapted to their context. Such an adapted approach to connector inspection for FTTH service activation will need to cover the following:
- Provide pass/fail diagnostics that reflect real conditions for the subscriber. Ideally, a graded rating would indicate the level of acceptability or not of the connection as to signal loss.
- Avoid need to interpret endface images, as this can be a source of delay and confusion.
- Be easy and quick to implement given the high turnover and needs in training for FTTH technicians, added to the fact that field crews are already heavily equipped for service activation.
Indicating only what really requires intervention, an adapted approach to connector inspection would be based on pass/fail verdicts that are designed specifically for last-mile FTTH to reflect the operational reality of broadband field crews.
Stay tuned for more handy information on this topic with our upcoming blogpost:
Flip your mindset about connection inspection!
Sources
- NTT Advanced Technology research, 2010
- Application note 191, Connector inspection and maintenance
