With the rapid development of broadband

mobile data

special line

IPTV and other services

the existing local transport network equipment type and plane is too much

the function is simple

the need for a variety of transport equipment stack

combined to carry various types of services. As the ultimate goal of the long-term development of the local delivery network

all optical transport network is a unifi ed all optical transmission network with multiple functions

large capacity

flat

high reliability

and more intelligent. The through the advantages and disadvantages of the analysis of long-term business development

the existing of different types of transmission equipment

research and analysis two transport network evolution route

evolution from OTN to all optical transport network and evolution of over OTN PTN to all optical transport network.