The cable should be longer than either of the following specifications, Event Dead Zone or Loss Dead Zone and the pulse length being used. The length of launch cable used can very depending on the measurement needs. But there are some general rules to follow. The better of the two to select is Loss. Premises cabling, which is short and often lower speed, is often multimode fiber, unless the network speed is >10Gb/s as in data centers, uses a GPON passive optical LAN or is shared with a cellular distributed antenna system. As the components like fiber, connectors, splices, LED or laser sources, detectors and receivers are being developed, testing confirms their performance specifications and helps. This test will measure the loss of an installed fiber optic cable plant, singlemode or multimode, including the loss of all fiber, splices and connectors. ) All multimode (MM) optical fibers stably propagate a plurality of guided optical modes. Practically, these may be thought of as paths which. Other than for short-reach single-mode applications that are more susceptible to reflections and take connector reflectance into consideration, insertion loss testing, length, and polarity are really all you need for Tier 1 certification testing. Measured in decibels (dB), insertion loss is the.