Low-latency high-efficiency mobile fronthaul with TDM-PON (mobile-PON)

To meet the capacity requirements of the exponential increase in mobile traffic and to continue to drive down the per-bit cost for mobile service providers, the cloud radio access network (C-RAN) has become a crucial step toward 5G. However, the current C-RAN architecture has some major drawbacks in terms of scalability, cost, and efficiency. In this paper, we propose and numerically demonstrate a novel mobile fronthaul architecture based on functional split and time-division multiplexed (TDM) passive optical networks (PONs) with a unified mobile and PON scheduler known as Mobile-PON. The optimal functional split distributes lower physical layer hardware toward remote radio sites. The new interface that divides the remote radio processing, and centralized baseband processing requires less bandwidth, also opens the possibility of sharing and multiplexing the bandwidth with multiple remote sites. Our combined mobile and PON scheduler is mainly based on the more complex wireless scheduling that translates its results into the TDM-PON system through LTE resource block mapping, eliminating additional scheduling delay at the PON. Without the additional scheduling delay, the cost-effective TDM-PON becomes applicable for mobile fronthaul, while the optimal fronthaul interface increases bandwidth efficiency by ∼10× over CPRI.