Study On The Sheduling Algorithm In OBS Network And The Implementation Of The OBS Edge Node

Optical burst switching (OBS) is a transitional optical switching technology between optical circuit switching (OCS) and optical packet switching (OPS). One typical feature of OBS is the separate transmission of data channels and control channels. Besides, one way resource reservation protocols are widely adopted in the OBS networks. Therefore, the optical buffers are not required at the OBS core nodes (compared with OPS) and the wavelength utilization is higher (compared with OCS). In this dissertation, the data channel scheduling algorithms are analyzed. Moreover, the ARM9 (Advanced RISC Machines 9) is used to implement the basic functions in the OBS edge node.Author's works are as follow:1. LAUC (Latest Available Unscheduled Channel) and LAUC-VF (Latest Available Unscheduled Channel with Void Filling) which are two typical data channel scheduling algorithms are firstly analyzed. And H-PPJET (Hops based Preemptive Prioritized Just Enough Time) scheduling algorithm that supports the Quality of Service (QoS) is proposed as a novel data channel scheduling algorithm, which based on the PPJET and LAUC-VF. Not only different data channels are assigned according to QoS by H-PPJET, but also the hop number and burst size are taken into consideration when discards the conflict bursts. Both the flow chart and illustrations of H-PPJET are given. Besides, simulations concerning the performance of H-PPJET are also done.2. Basic functions of the OBS edge node are accomplished by modifying the source code of Linux Kernel. Both the framework of burst data packet and burst control packet are devised based on the standard structure of the Ethernet frame and IP frame. In addition, the burst assembly algorithm and data channel scheduling algorithm are analyzed and corresponding processing flow are proposed.3. Kernel Module is adopted to modify the Linux kernel and acquires the information of IP packets from the Linux stack. What's more, basic functions of OBS edge node such as burst assembly, data channel scheduling and data transmission are implemented according to Kernel Module methods.