Cost-effective scalable and robust star-cross-bus PON architecture using a centrally controlled hybrid restoration mechanism

With traffic carried by fiber access networks continuously increasing, the survivability and scalability of networks have become critical for their applicability. In this paper, a low-redundancy passive optical network (PON) architecture using a star-cross-bus topology is presented along with a scale-differentiated, centrally controlled hybrid failure localization and restoration procedure. The network can provide protections for the feeder and distribution fibers as well as the optical line terminal transceivers, where multiple failures can be restored within 2.1–8.2 μs with local failures restored locally. Analyses show that the network is highly survivable and that its expected survivability for a 128-ONU PON with 16 failures can be 8%, 9 times, and 8 times higher than those of dualfeeder-star, ring, and dual-ring networks, respectively. In addition, the network is also scalable such that hundreds of to a thousand optical network units (ONUs) can be accessed for loss budgets of 30–40 dB.