Abstract: Provided are a time synchronizing method and apparatus based on a time stamp. The time synchronizing method includes: transmitting a local time stamp based on a free-running local clock to a master node; receiving a response time stamp from the master node; calculating a delta time value based on the response time stamp; filtering the delta-time using a digital low pass filter running at the free-running local clock rate; and adjusting a local clock time based on the filtered delta time value.

Abstract: Disclosed is a clock recovery method and apparatus for CBR traffic in the packet switching network so as to recover the clock of the CBR traffic upon transmission by inserting a small amount of random packets to the CBR traffic stream which has arrived in a receiver. According to the present inventive concept, the CBR streams are added with the random traffic streams in the packet switching network, so that the clock of the CBR streams upon transmission can be recovered, and jitter and wander according to clock recovery can be reduced.

Abstract: A method, core node, ingress edge node, and egress edge node for matching a bit rate of data input into an optical burst switching network with that of data output from the optical burst switching network are provided. The method includes calculating a difference between a frequency of optical data received on a node and a natural frequency of the node; including the calculated difference into control information; and transmitting the control information. The core node includes a calculator to calculate a difference between frequency of optical data and the natural frequency of the optical data; and a controller to add the difference and a difference included in control information, and output the added difference. The ingress edge node includes a data processor; and a controller. The egress edge node includes an ingress edge node clock recovery phase lock loop; a de-mapper; and a storage unit.

Abstract: An apparatus and method for adjusting a receiving time point of burst data in an optical burst switching network is provided. The method includes comparing a reference time point of a node with a time slot boundary of the burst data; and adjusting the time slot boundary of the burst data in accordance with the reference time point. The apparatus includes a sync detection section which is configured to detect a difference between a time slot boundary of the burst data and a reference time point; and a sync control section which is configured to control shifting and re-aligning the received burst data with the reference time point according to the difference detected by the sync detection section.

Abstract: A time-slotted optical burst switching system and method therefor can support data transmissions for a constant bit rate (CBR) and at a variable bit rate (VBR) and improves a data transmission method at an edge node and a core node. Accordingly, it is possible to perform a data service for the constant bit rate and for a variable bit rate and to substantially prevent a delay due to a scheduling for a slot assignment at the core node by transmitting a burst control packet before the data burst to be transmitted at the edge node is generated in case of transmitting the data burst at the constant bit rate.