The Research Of Upstream Bandwidth Resource Management In NG-EPON

With the rise of new industries such as cloud computing,big data processing,ultra high definition video service and video conference,as well as the rapid increment of network users,industry and academia are exploring network equipment with excellent performance constantly to satisfy the request of the users' traffic.Passive Optical Network(PON)has been widely adopted because of the high network capacity,low cost,wide coverage and so on.It has become the most popular solution in access network.EPON,GPON,10G-EPON and XG(S)-PON provide users high rate access experience.However,as the increment of users' high bandwidth request and the rapid development of new industries business,PON technology cannot satisfy the need of bandwidth.To support the upgrade of PON technology,IEEE and ITU-T are working for the standardization of the NG-EPON and XGS-PON.This research mainly focuses on the NG-EPON.IEEE 802.3ca charges for the standard of NG-EPON.NG-EPON provides several wavelengths for Optical Network Unit(ONU)to transmit,each wavelength provides 25 Gbps transmission rate.By introducing the wavelength-division multiplexing technology on the basis of time-division multiplexing,ONUs equipped with multiple transceivers can transmit on several wavelengths or single wavelength.It improves the transmission rate significantly.Although NG-EPON provides multiple wavelengths could enhance the capacity of the access network,it truly incurs many technology problems such as the efficient bandwidth resources allocation,the wavelengths allocation and the disorder problems of data frame on several wavelengths.In this paper,we consider the efficient schedule of NG-EPON upstream channel bandwidth resource,combining NG-EPON multiple wavelengths allocation and the large geographic coverage.We research the schedule mechanism of OLT in NG-EPON,and then propose novel DWBA algorithms named agile wavelength DWBA(AW-DWBA)to improve the upstream channel bandwidth utilization.We take the schedule order of ONUs,which wavelengths should allocate to ONUs and the size of transmission windows in each wavelength for ONU into account.AW-DWBA algorithm based on the offline schedule framework.After the analysis of AW-DWBA,we develop this algorithm and propose two stages DWBA(TS-DWBA)algorithm to get the higher performance.As there will be some network business which request low delay,the network operators have to consider the impact of delay when adopting schedule strategy.We study further and propose a novel algorithm named DWBA Just In Time(DWBA-JIT)based on Online Just-in-Time schedule framework,which could improve the average packet delay while use the bandwidth resources efficiently.Finally,we simulate the proposed algorithms respectively.And the simulation result shows the validity of the proposed algorithms which perform better than the existing algorithms in average packet delay and upstream channel bandwidth utilization,especially when network load is high.