OFDMA-based LAN emulation in long-reach hybrid PON system

A novel long-reach, hybrid wavelength-division multiplexing (WDM) and time-division multiplexing (TDM) passive optical network (PON) architecture which supports local area network (LAN) emulation among customers is proposed. Orthogonal frequency division multiplexing access (OFDMA) technology is used in optical network units (ONUs) to transmit the LAN data. The optical LAN data from an ONU is converted into the electrical signal and combined with TDM downstream access data in the extended box for delivery to other ONUs. This scheme has many advantages on LAN emulation, such as dynamic allocation of LAN bandwidth, no bandwidth cost of TDM business, supporting multiple concurrent LAN services and so on. Simulations are performed to verify the scheme. Tolerance of dispersion and factors that influence the performance of various independent services are all investigated and analyzed. ►A novel long-reach (80km), high-bandwidth (80Gbps in back-haul fiber), high-split (8x32), hybrid WDM and TDM PON system which supports LAN emulation is proposed. ►The LAN traffic from an ONU is converted to the electrical signal and then combined with downstream traffic in the extended box for delivery to ONUs. In this way, the low cost and efficient LAN emulation among ONUs directly on the optical layer are established. ►By using the RF subcarrier multiplexed transmission, the LAN traffic will not occupy the bandwidth of the up/downstream traffics. ►The bandwidth of the LAN traffic could be flexibly adjusted and multiple LAN traffics could be simultaneously transmitted due to the use of OFDMA protocol.