Topic: Converting Media To Fiber Optics
|Converting Other Media To Fiber Optics
Most computer hardware comes with an Ethernet port for connecting to the Internet or LANs that requires a Category 5/5e/6/6A unshielded twisted pair (UTP) cable connection. Laptops will generally include a wireless (WiFi) connection also. Video cameras usually have a coaxial cable connection. All of these often require connections into fiber optic networks also.
Sometimes that connection is done with dedicated hardware like LAN switches that connect to PCs over UTP and the LAN backbone over dedicated fiber ports. Some wireless access points connect over UTP, others have fiber optic ports. Some video cameras now come with dedicated fiber connections instead of coax. But often, it's necessary to convert other media to fiber or even sometimes multimode fiber to singlemode or vice versa.
This conversion is accomplished with a device called a "media converter." A media converter does what its name says - converts from one media to another. The most widely used converters are probably the ones used to convert computers UTP Ethernet ports to fiber for a "fiber to the desk" (FTTD) system using centralized fiber architecture. (For more on FTTD, see the TIA Fiber Optic Lan Section website: http://fols.org/. )These same converters can be used to connect wireless access points to a LAN.
A fiber optic media converter is very similar to a fiber optic transceiver, except it is intended to be used external to connected hardware rather than be built into the equipment. It consists of a interface on one end that matches a standardized interface (e.g. copper 1000base-T or Gigabit Ethernet over Cat 5e), some internal electronics that convert the signals to be compatible with optical fiber and fiber transceivers.
The fiber compatibility required will determine the type of fiber transmitters used, LEDs for slow multimode systems, VCSELs for faster gigabit multimode systems and lasers for singlemode systems. The conversion electronics will be determined by the interface type. Digital signals in LANs require different conversions than analog CCTV cameras or CATV broadcast systems, for example.
Not all media converters convert copper signals to fiber. Some convert multimode to singlemode where the user needs to connect signals over longer distances or only has singlemode fiber available on a link cable run. Some convert analog signals to digital, some may multiplex several signals over one fiber pair, or perform other signal processing.
Since most applications require replacing copper cabling with fiber, the link will include media converters at each end of the link connected with fiber. At either end, the hardware can connect with compatible copper ports and the transmission can be over fiber.
Media converters may require outside power sources or may operate from signal power or standard interfaces (Power over Ethernet, USB, etc.)
Table of Contents: The FOA Reference Guide To Fiber Optics