Understanding the network.pdf - Back to Home

Multimode's larger size permits multiple pulses to be carried across the strand. With
this larger size, it is more forgiving of transport errors, which commonly occur at the
media interconnects. The "forgiveness" factor of multimode makes it better suited
for LAN applications, where multiple path interconnections are the norm. The
downside of multimode is that it suffers from modal dispersion. As different light
pulses reflect at different angles off the fiber core, there is a possibility that pulses
sent at the same time will reach the end at different times due to the number of
times the pulse has been reflected. This delay can result in signal misinterpretation.
Single-mode, with its smaller core diameter, can only carry one signal, so it does not
suffer from modal dispersion and can therefore transfer data farther without any
regeneration assistance. Figure 4.3 illustrates the differences between multimode
and single-mode.
Figure 4.3. Light paths in multimode and single-mode
fiber.