Access Network

Another specific use case within the telecoms network where TXO Optics is gaining customers is in the area of the access network. TXO Optics is producing compatible modules for the end point in a passive optical network, the so-called OLT or optical line terminal. TXO Optics has experience across a wide range of vendor’s equipment for use in the GPON environment. For convenience some customers also require transceivers with dual compatibility with the router that is used in conjunction with the access equipment such as the Alcatel/Nokia 7750 device.



GPON stands for Gigabit Passive Optical Network. The passive part comes from the fact that passive elements such as splitters and combiners are used rather than active elements like amplifiers and repeaters and so on. This type of technology is commonly deployed by the operator to deliver internet, VoIP (Voice over Internet Protocol), and TV to residential customers. Some of the traditional downsides such as limited reach (typically 20km) have recently been overcome by Google Fiber which claims to be achieving 50km by using custom optics. See Google Fiber for more details.

In this architecture we see a central office node called the Optical Line Terminal (OLT) and user nodes called optical network terminal (ONT) in the subscribers’ premises with the network comprised of fibres and splitters in between. Production of BiDi transceivers for use in GPON environments tested in Alcatel ISAM are available as well as Calix.