Fiberoptic.com is excited to annouce Huawei Technologies Co Ltd.’s prototype optical transceiver with embedded optical time-domain reflectometer (eOTDR) functionality, which the company claims could significantly reduce the cost of troubleshooting in fiber-to-the-home (FTTH) networks. An OTDR detects backscattered light in optical fibers and uses this information to compute the location of faults.
Traditionally, FTTH maintenance and troubleshooting has to be performed through external OTDR equipment, which requires the test kit to be connected to the fibers under test – a complex and costly operation. There can also be problems “seeing” the network on the other side of the splitters in passive optical networks (PONs) because splitters add attenuation to the optical signal. Using emulation tests on live networks, Huawei says it has demonstrated that its eOTDR prototype can accurately locate faults to within 5 meters in networks with a split ratio of up to 1:64.
The eOTDR technology is ready for commercial use, the company claims. Chris LaBonge, CEO of Fiberoptic.com, commented on the incredible potential of this new technology. “I expect this technology will redefine the way OTDRs are used in the industry. We are now looking for OTDR technology to report proactively within an active network environment. It’s fast and very efficient – eOTDRs give operators a level of physical layer management that just hasn’t been available up until now.” The OTDR functionality is embedded into an optical transceiver inside the PON optical line terminal (OLT), operating at the same wavelength as the user data. These optical modules are the same size as common optical modules and can be easily deployed in the central office. This approach eliminates the need to reconfigure optical fibres and doesn’t interrupt services, making the troubleshooting process more efficient and less expensive, according to Huawei.
Last year, Alcatel-Lucent also announced embedded OTDR functionality in an SFP module, which plugs into the Intelligent Services Access Manager (ISAM) platform. Its technology can locate fiber cuts anywhere within 20 km in the shared part of the network, but the insertion of a 1:4 splitter reduces the visibility to just 5km from the central office, according to technical documents.
Although Huawei claims that its embedded OTDR module can work with higher density splitters, it’s not yet clear how much the technology is restricted in terms of distance.
