We introduce an intelligent optical cross connect (OXC) structure based on our lambda-group model, as well as a dynamic algorithm of configuration helpful to complicated optical traffic grooming, which presents a distinctive approach of dividing granularities into specific tunnels for effective treatment. Results and figures from experiments show that the particular channel partition not only is helpful to port reduction significantly, but also improves the channel and blocking performance for dynamic connection requests.
Traditional burst assembly method only differ service class priority by increasing extra offset time so as to assure QoS at Optical Burst Switching (OBS) core node which increases all network delay extremely, especially for optical network with many hops and large radius. In order to take full advantage of flexible buffer and control function of electronics device and optical large capacity predominance, it is desired to process real-time traffic at edge ingress node and guarantee delay fairness under small enough delay and QoS based on offset time differentiation for various classes. To
achieve lower assembly delay at OBS edge node and offset time based QoS guarantee at core node, this paper proposes an approach called Prediction and Offset QoS Assembly (POQA) to improve existing burst assembly mechanism at edge node. POQA method takes into account the delay fairness and QoS-based offset time adequately. The ratios of assembly time and offset time are introduced to make a delay and offset differentiation among various traffic classes. Assembly delay, burst size, burst utilization and length error of various classes are compared under different offered load. Moreover, in contrast with traditional time assembly method, simulation results show that POQA method can achieve a significant improvement in terms of burst delay and utilization and realize the delay fairness and offset time QoS differentiation under different traffic offered load.
A kind of optical coarse packet switching based on optical label routing is intrduced. In the switching, the swapping granularity is coarse compared to common optical packet switching, and the header of optical packet is labeled by multi-wavelengths. Some realization techniques on core switching node and edge node with terminator are studied. A principle experiment system is established to perform the optical coarse packet transmitting, switching, and receiving, and verify the feasibility of such optical coarse packet switching.
A multi-wavelength optical label switching test-bed is introduced. The optical label is constructed by a series of optical pulses with different wavelengths that are in the same WDM optical channel. High speed optical switches and DSP chips are used to process the optical label signal. The four-node programmable optical label switching network is demonstrated by transmitting PC capture signal and multimedia video flow with standard Gigabit Ethernet frame.
Furthermore, an optical packet assembly and segmentation method is proposed for Gigabit Ethernet Optical Label Switching networks. Two timers are used to realize the exact timing on microsecond magnitude between optical label and programmable optical Ethernet packet. The experimental system executes the real time process and the Gigabit
Ethernet data packets with optical label are switching and transmitting successfully. The optical packet programmable method enhances bandwidth utilization and throughput, increases the intelligence, flexibility and multi-service bearing ability of the Optical Label Switching network.
The current edge assembly granularity preserved beforehand in optical burst switched (OBS) networks lacks flexibility to actual network traffic and increases assembly overhead and delay. Offset time generating mechanism after traffic shaping increase network delay and cut down its robustness. Consequently, it is significant to present an effective dynamic burstification scheme to process real-time traffic, reduce assembly delay and provide QoS guarantee for different priority traffic at edge node. This paper focuses on dynamic burst assembly at edge node in optical burst switching networks, which can be implemented to improve the performance of the whole network. Based on traffic prediction, a new dynamic adaptive assembly mechanism on load estimate, termed Dynamic Adaptive Assembly (DAA), is proposed to reduce assembly delay, estimate real-time network traffic character and dynamically adjust Burst Assembly Time (BAT) at edge node. The dynamic range of BAT for four traffic classes is introduced to make compare among current and previous prediction with different prediction time under QoS based offset time. We investigate the influence of current and previous offered load with different prediction time and offset time. Simulation studies are
carried out for various traffic classes. The results show that DAA can achieve little delay and provide adaptivity, flexibility and delay fairness for burst assembly.
A kind of optical multi-wavelength label switching adopting Gigabit Ethernet technology is introduced. In this switching, optical header is labeled by several optical pulses at different wavelengths in the same optical communication channel band as optical payload, and a specific Gigabit Ethernet adapter is used as the optical payload sender and receiver. The principle of optical switching is explained, and a demonstration experiment is described.
The rapid increase of IP service and large capacity in DWDM layer request the all-optical packet delineation and process. Optical burst switching is a promising technology in the future IP/DWDM networks, which provide a feasibility to realize the optical packet switching without optical buffer. Presently the QoS guarantee of OBS depends on the bandwidth control protocol. JET based on RFD generally applied in OBS network is considered in this letter. According to the queuing theoretical model, the performance of one node is studied using simulations. Besides the traditional exponential arriving and service traffic, we analysis the general and self-similar traffic under the same average service time. The analysis and simulating results for different class have important effects on networking performance by comparing the queuing service models.