Researches On MAC Scheduling In Novel OFDMA-PON Systems

To meet the demands of longer distance and larger bandwidth in the fast developingoptical network in recent years, Passive Optical Network (PON) is becoming a promisingmethod to solve the fiber-to-the-home (FTTH) problem in access network. In2008, NEClaboratories, Princeton, introduced Orthogonal Frequency Division Multiplexing (OFDM)technology into PON for the first time on the European Conference on OpticalCommunication (ECOC). Because of its high utilization in frequency domain and gooddispersive resistance, OFDMA-PON can achieve larger capacity than TDM/WDM-PONwhich is used today.Recent years, researches on OFDMA-PON are mainly focused on the physical layer, notMAC layer. To study the MAC layer in OFDMA-PON is crucial in improving networktransmission and system performances. Therefore, it is meaningful for both commercialapplications and scientific researches. Various MAC scheduling techniques in novelOFDMA-PON are studied in this paper, including subcarrier assignment inservice-differentiated OFDMA-PON, sleep mechanism in ROF-OFDMA-PON and thetransmission effect of switch latency in stacked WDM-OFDMA-PON.The main contents of this paper could be divided into the following aspects:(1) Introducethe development of OFDMA-PON, the importance of its MAC scheduling and some of theresearches about MAC scheduling in OFDMA-PON, including resource allocation algorithms,sleep mode and switch latency;(2) Study the application of differentiated services inOFDMA-PON about its necessity and the service levels. Based on the service-differentiated system, we propose fixed and dynamic subcarrier allocation algorithms and compare themthrough simulations;(3) Propose new sleep mechanism in ROF-OFDMA-PON and useMarkovian chain models to analyze its performances;(4) Study how the switch latency oftunable optical filter affects the transmission delay and make improvement to the transmissionalgorithm in the experimental stacked WDM-OFDMA-PON;(5) Conclude this paper andraise some problems for future researches.