Mobile Fronthaul over Latency-Optimized Time Division Multiplexed Passive Optical Networks

Transport of fronthaul traffic has a tight latency requirement of about 250us one-way. Currently, the main solution for fronthaul is based on point-to-point (PtP) fiber links and PtP WDM, but these are expensive. A time division multiplexed passive optical network (TDM-PON) is simpler and more commonly available; however, a standard TDM-PON (e.g., GPON, XGPON) has latency around 1ms. Guidelines are suggested to design an optimized TDM-PON with minimal latency for transport of constant bit rate fronthaul traffic. The total latency is mathematically analyzed using queuing theory providing closed-form formulas allowing to study the trade-offs between different parameters. Feasibility of low latency is established in several application scenarios.