Research On Optical Buffer Based Contention Resolution Scheme In OBS Networks

As the development of the IP internet technology and the emergence of the newnetwork services, internet develops rapidly all over the world, at the same time, puttingforword a higher demand on the transmission network. Hundreds of wavelength channelare carried on single fiber with advances in dense wavelength division multiplexing,channel bandwidth of Tbit magnitude, dramatically improves the transmission speed.Howover, existing network switching architectures are unable to support bursty IPservices, and will not fully utilize the massive bandwidth of the fiber. Optical burstswitching(OBS) has been proposed as a new paradigm to achieve a practical balance, itcombines the merits of optical circuit switching(OCS) and optical packetswitching(OPS) while avoiding their defects, OBS has been an attractive subject withgood prospects.As OBS using one-way reservation, the probability of contention between the burstdata packet(BDP) is larger than the traditional switching, resulting in more BDP loss,and a BDP contains more than one IP packet, once contends will lead the loss ofnumbers of IP packet directly effecting the overall network performance. Therefore,contention resolution scheme is one of the key issues in the OBS network.Targeted low transmission efficiency caused by the BDP contention, the thesisresearchs on optical buffer based contention resolution scheme in optical burstswitching networks. On this basis, presents single business and multi-business classifieddiscussion method. Given analysis of burst packet loss probability、burst packet averagedelay and other performance data equipped with different numbers of fiber delayline(FDL) in detail. The analysis of single business contention shows that, when singlewavelength channel load is0.1、0.6and0.9respectively, the burst packet lossprobability reduces about25、5and1.5magnitude while equipped with6FDLscompared with no FDL. When single wavelength channel load is greater than0.8, thenumber of FDL changing from2to6, when adds2FDLs, the number of burst packetsper unit time into the system inreases7%and10%. When single wavelength channelload is0.9, the number of FDL changing from2to4into6, the burst packet averagedelay time of the system increases80%and140%. The analysis of multi-business contention shows that, while the volume of five type business is equal, the number ofFDL changing from0to2, the burst packet loss probability of five type business,changing from the highest priority business to the lowest priority business, reducesabout14、13、11、9and8magnitude. When single wavelength channel load is0.1、0.4、0.8、0.9and1respectively, the burst packet average delay of the lowest prioritybusiness is2.5、3.1、8、12.5and17times respectively compared with the burst packetaverage delay of the highest priority business.