ONT SFP GPON: End-customer solution

gpon solutionsWith the deployment of fiber to the home (FTTH), telecommunications operators put their main focus on the residential market. This is logical, since it is where there is volume and where a small increase or decrease in revenue per subscriber is converted into outstanding results on their financial accounts.

As with almost any other access technology, once the number of households with the possibility to receive the service is steadily increasing and the network is stable and running, many operators also choose to use this deployment to offer their services to the business market.

PON (passive optical network) technologies, that enable the deployment of FTTH networks in a cost-effective manner for the residential market, are evolving at a high speed. Not only as far as protocols and standards are concerned, which are constantly enabling further increases in speed, but also at “chip” level, since it manages to implement the mentioned protocols and standards in forever smaller and more efficient integrated circuits.

GPON services

Until now, to offer GPON services, currently one of the most used PON variants, the service provider had to typically install three devices at the customer’s home: (1) the “optical modem”, known in the “official” terminology as ONT, (2) the IP access router, which allows the connection of multiple devices and also typically includes a Wi-Fi access point, and optionally (3) Set-Top-Box or video decoder, if television services (IPTV) are required.

In the majority of cases, the ONT and the access router are really two different devices, when they could be only one device, as is the case with ADSL routers, which include internally an ADSL modem. Apart for using one modem in MTU (multi-user) topologies, in which several routers “hang” from one “optical modem”, this lack of integration is a sign of the lack of technological / GPON service maturity, compared for example with the mentioned ADSL technology.

An “internal type” reason for this separation between the ONT and router is due to the organizational structure within the telecom operators, whereby the ONT is considered as equipment that belongs to the operator’s own network, but located at the customer’s home, while the router is considered as customer’s network equipment and therefore managed by different departments within the operator. However, the end customer does not care and the only thing that he/she sees, is that for a FTTH service, the operator has put two boxes when the ADSL service only requires one box.

ONT GPON devices in SFP format: Convincing solution

The technological advances mentioned above are allowing the emergence of ONT devices with a SFP format (Small Form-factor Pugglable), which are normally used for other more simple optical transceivers. The SFP format allows you to provide communication equipment with fiber interfaces in a modular way, so that in a common “chassis” you can insert or connect different types of fiber. So far using the SFP ONT format devices had been residual, due to the inherent complexity of GPON and the impossibility of implementing all the necessary processing capacity into the small size of the SFP connector. It had reached the SFP ONT device market, but with a special mechanical format “backpack type”, which has consumption and heating problems.

However a new generation of chips, which have a very small size and low power consumption, is making possible the emergence of GPON ONT devices in a standard SFP format. Now the question is whether the operators will be able to organize themselves internally to transfer to the customer the advantages of a much more convenient deployment. This will indicate whether the GPON technology is “maturing”.

At Teldat we hope that this does occur, since we think that the SFP format for a GPON ONT  is a very attractive and convenient solution for the end customer, since it means a lower cost, lower consumption and the reduction or integrating of devices.

Eduardo Tejedor: