Multi-Gigabit CO-OFDM System over SMF and MMF Links for 5G URLLC Backhaul Network

The 5G cellular network aims at providing three major services: Massive machine-type communication (mMTC), ultra-reliable low-latency communications (URLLC), and enhanced-mobile-broadband (eMBB). Among these services, the URLLC and eMBB require strict end-to-end latency of 1 ms while maintaining 99.999% reliability, and availability of extremely high data rates for the users, respectively. One of the critical challenges in meeting these requirements is to upgrade the existing optical fiber backhaul network interconnecting the base stations with a multigigabit capacity, low latency and very high reliability system. To address this issue, we have numerically analyzed 100 Gbit/s coherent optical orthogonal frequency division multiplexing (CO-OFDM) transmission performance over 400 km single-mode fiber (SMF) and 100 km of multi-mode fiber (MMF) links. The system is simulated over optically repeated and non-repeated SMF and MMF links. Coherent transmission is used, and the system is analyzed in a linear and non-linear regime. The system performance is quantified by bit error ratio (BER). Spectrally efficient and optimal transmission performance is achieved for 400 km SMF and 100 km MMF link. The results designate that MMF links can be employed beyond short reach applications by using them in the existing SMF infrastructure for long haul transmission. In particular, the proposed CO-OFDM system can be efficiently employed in 5G backhaul network. The multi-gigabit capacity and lower BER of the proposed system makes it a suitable candidate especially for the eMBB and URLLC requirements for 5G backhaul network.