An OBTN is an optical transmission technology of which a granularity is between Optical Circuit Switching (OCS) and Optical Packet Switching (OPS). A key idea is to separate a control channel from a data channel by fully utilizing the huge bandwidth of an optical fibre and the flexibility of electronic control. The data channel conducts an all-optical switching technology by adopting data frames, wherein for the data frames, an Optical Burst (OB) is taken as a switching unit. The control frames in the control channel corresponds to the data frames in an one-to-one manner, and the control frames are also transmitted in an optical domain, and are, however, converted, at a node, to a circuit domain to be processed so as to receive and update corresponding control information. It can be understood that: there may be more than one data channel and more than one control channel. When bursts on a plurality of data channels compete in output, a burst in each data channel may be delayed by using a segment of Fibre Delay Line (FDL), and delay time is exactly equal to time for processing a control frame by each node, thereby making up for a time delay difference between the control channels and the data channels to solve the problem of competitions. Thus, the OBTN can achieve dynamic adaption and good support to various traffic scenarios, can improve the utilization efficiency of resources and the network flexibility, retains the advantages of high speed, high capacity and low cost of an optical layer, and is applied to various star/tree/ring-shaped network topologies.
However, in a current OBTN technology, high cost will be brought by using the FDL. Meanwhile, such a time slot synchronization method is not simple and easy, it is necessary to fix an optical fibre distance between the adjacent nodes and to fix a distance relationship between the control channel and the data channel, and establishment and adjustment are not facilitated when the ring length of the network changes.