Reliability considerations of the emerging PON-based 4G mobile backhaul RAN architecture

This work proposes a fully distributed protection mechanism for a ring-based wavelength-division-multiplexed passive optical network (PON) broadband access architecture that can be utilized as an all-packet-based converged fixed-mobile access networking transport infrastructure for backhauling mobile traffic. Such an architecture will enable the true integration of PON-based and fourth-generation mobile broadband access technologies into the envisioned fixed-mobile platform. Specifically, this paper proposes two different fault detection and recovery schemes, namely, fully distributed and hybrid (distributed/centralized). In this ring-based architecture, each optical network unit can independently detect, manage, and recover most of the networking failure scenarios. The proposed protection schemes are capable of protecting against both node and distribution/trunk fiber failures and enable the recovery of all network traffic including upstream, downstream, and LAN data. In addition, these schemes can also protect against any combination of concurrent double failures including trunk/distribution fiber breaks and node failures. The hybrid architecture delivers these efficient resilience capabilities and incurs almost no additional power loss compared to that of the normal working architecture.