A group of professionals has teamed up to form ‘Sardana project’, which intends developing key techniques to hone the strength and scalability of the widely used fibre-to-home networks.
The project titled 'Scalable advanced ring-based passive dense access network architecture' is being carried out by a group consisting of one telecom operator and experts from equipment vendors, research institutes, and universities. The project is based on existing fibre infrastructure and off-the-shelf components. The European Commission has granted € 2.6 million for this project.
Conventional Passive Optical Networks (PONs) resemble a tree-like structure, wherein their root includes telephone exchange central office. Optical splitters requiring no extra power is used and this passive structure divides into components of homes and businesses. Conventional tree PONs is based on Time Division Multiplexing (TDM), where a 5 Gbps connection in the central office is transformed into a 30 Mbps downstream connection on reaching the destination.
The Sardana researchers are devising a new approach. Here, a main ring replaces the single big tree and the signals are bidirectionally transmitted from the central office using the ring. The transmission application of the ring is based on Wave Division Multiplexing (WDM), with different wavelengths of laser light. Based on TDM technology, the signals divide to homes and businesses onto single fibre trees at Remote Nodes present along the ring. Even if the cable is broken at any location on the WDM ring, the bidirectional ring transmits the signal from the other direction, thereby increasing connection speed.
Finnish equipment vendor, Tellabs conducted a field trial in Brittany, France, and demonstration at Milan’s Fibre to the Home Council (FTTH). Based on emulation technology, the network is able to serve over 4,000 users within the main ring of 20 km, with symmetric internet of speeds up to 300 Mbps. The technology enables optical signals up to 100 km for 250 homes with asymmetrical 10 Gbps downstream and 2.5 Gbps upstream connections.