Passive Optical Networks

restoration time. This time period should be kept small, say less than a few tens

of milliseconds [8], to reduce the amount of data loss during service disruptions.

In most cases, such traffic restoration time greatly depends on the intrinsic

response of the optoelectronic detection and the optical switching devices used

in the APS, as well as the possible induced additional latency of the protection

lightpath. Sometimes, higher-layer protocols are employed to retransmit the lost

data.

6.2.9 Complexity

The design of survivable PON architectures should require the least amount

of additional fiber link or equipment duplication to keep the complexity and cost

low. For example, a backup transceiver may be employed at the OLT for 1:N

protection of all other ...