Passive optical network system for realizing protection switching and protection switching method

Abstract

A passive optical network with protective switching over consists of ring network formed by OLT and passive mating node, ONU branch connected on mating node, two sets of light receiving / transmitting modules set in OLT, 2x2 coupler and 2x N coupler set in mating node. It is featured as connecting a pair port 1 and 3 of 2 x 2 coupler to said ring network and another pair port 2 and 4 to port 5 and 6 of 2 x N coupler, connecting the other N numbers of ports at 2 x N coupler to ONU, enabling to switching over two said sets from one set to another set when one is fault.

Description

technical field [0001] The invention relates to the technical field of optical communication, in particular to a passive optical network system capable of realizing protection switching and a protection switching method based on the system. Background technique [0002] At present, in the planning of urban access optical networks, the laying methods of optical cables generally used can be found in figure 1 As shown, the thick solid line in the figure indicates the optical cable on the metro ring network, the thin solid line indicates the optical cable connected to the backbone ring, the dotted line indicates the access chain optical cable, and the dotted line indicates the access branch optical cable. Install active sub-office computer rooms on the metropolitan area ring network, lay optical cables in a ring along the road from the sub-office computer room to the user direction, and place several passive optical transfer boxes along the way. Usually, the optical cables arra...

AI Technical Summary

Problems solved by technology

However, this protection switching method requires dual routing of branch optical cables, which requires each ONU to provide two sets of branch optical cables with different routes, and the cost is relatively high for the access network environment with a large number of user nodes.

And in the actual access network planning, the branch optical cable from the transfer box to the ONU is usually set as a single route. If it is applied in practice, the existing network must be modified on a large scale, and the cost is very high; otherwise, if only in the existing Adding a branch optical cable to the optical cable path between the ONU and the OLT will easily cause the two branch optical fibers of the ONU with protection requirements to fail at the same time, and the protection switching of the ONU branch cannot be truly realized.

Images