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Optical Telephony Systems (FWL)


The FWL family of optical voice transmission systems uses an advanced digital communication technique for voice communication through a single fiber. It can be configured for singlemode or multimode fiber operation, in any of the 1550nm, 1310nm or 850nm windows, with high performance LASER's or LED's. Standard singlemode fiber and 1550nm operation yields long distance reach, typically up to 200 km. Applications include: private telephony, service channel, communication between field technicians during maintenance of telecom networks etc. It is also recommended for applications in hazardous environment (explosion risk, high electromagnetic field interference etc). The FWL family can fast return your investment, reduce operational costs with telecom services etc. It is divided in three product lines, serving different applications and market needs:

FWL211 Digital Optical Talk System

Application: Voice communication between field technicians

The "FWL211 Digital Optical Talk System" is designed for high quality voice communication over optical fibers. It is a compact and portable equipment with interface to PBX and Public Switched Telephone Networks (PSTN). FWL211 uses advanced digital communication techniques for voice communication through a single fiber.

It finds several applications and differentials, such as:

  • Communication between field technicians during installation, testing and maintenance of fiber networks
  • Communication between field sites and company offices
  • Communication in electrical power transmission lines and other utility companies whose right-of-way are equipped with fiber cables (OPGW cables etc.)
  • Communications in hazardous environments (explosion risk classified areas, high electromagnetic field interference environments etc)
  • Remote connection to PBX and PSTN
  • Dial-up telephone extension
  • Private telephony
  • Fiber identifier
  • Fiber continuity tester
  • 2KHz tone transmission and detection
  • Head-set as well as hand-se operation.

Additional useful FWL 211 functionalities inclue:

  • Computer data communication
  • Remote instruments access and control via RS interface

The FWL211 can also be used to replace radio communication, walkie-talkies, mobile and satellite telephony which are affected by RF interference and low QoS. It fast return its investment, through greatly reducing operational costs. The option of local and remote connection to PBX and Public Switched Telephone Networks brings advantages as:

  • Conference calls between field operators and company offices
  • External remote calls
  • Mobile and satellite phone bill savings
  • Service quality improvement

Its high sensitivity allows clip-on communication without cutting the fiber. Click here to see the FWL211 technical specifications. The FWL211 is a unique instrument. However, for the specific application of voice communication between field technicians during installation, testing and maintenance of fiber networks, it does have some competitors.

FWL220 Optical Telephone System

Application: Private enterprise telephony

The "FWL220 Optical Telephone" is a telephony system for high quality voice communications through optical fibers. It allows communication between telephone extensions located up to 180 km apart, using just one optical fiber. Widely spread offices, buildings, industrial plants and road emergency points can then be integrated into a single private telephony system, without the need of leasing electrical channels from telecom carriers or investing in acquisition of layers and sub-layers of expensive telecom equipment. The customer can use its own fiber or lease/buy dark fiber, which has become largely available at decreasing costs. The FWL220 can be connected to PABX systems, thus expanding the customer plant of telephone extensions. It also allows connection to the Public Switched Telephone Network and thus external remote calls.

FWL250 Optical Service Channel

Application: Voice communication between fiber network sites

The "FWL250 Optical Service Channel" was developed for voice communication between fiber network sites. It replaces, with superior performance and lower cost, the electrical service channels available in the market. It offers integration with Public Switched Telephone Network and PABX systems. These features allow field engineers and technicians to communicate not only between network sites but also with the company's offices and external Public Telephone Network. FiberWork's FWL250 operates as an open channel, where all network nodes have access to the same conversation simultaneously (multiple access). It can also be configured as a private channel, where the signal passes through every node except the destination node (P2P communication). The FWL250 is an ideal solution where dark fibers are abundant. However, it can be used with active fibers as well, using a different wavelength from the working optical channels. In this case, it will be necessary to employ the FiberWork’s ACTIVE Solution. For ultra-long-reach applications, the FWL251 Regenerator may be used for signal regeneration.

* Contact FiberWork for additional information.