Abstract In this era of capricious Infobesity, every technology demands advancement in the form of increased bandwidth and lower latency, which can be provided by wireless optical broadband access network. Wireless Optical Broadband Access Network (WOBAN), conflating the benefits of both optical networks by providing higher data bandwidth, low latency, long communication lines, low loss, high reliability, high performance-to-cost ratio, etc. and wireless networks by providing greater accessibility, flexibility, easy networking. Due to various advantages of WOBAN as compared to the contemporary broadband networks, WOBAN has been a recent attraction for various researchers. Survivability is one of the critical issue in WOBAN due to its high speed characteristics. To handle this failure particularly distribution fiber failure, we present this work to identify critical wireless routers and their optimum positions. Here critical wireless routers are necessary to transfer disrupted traffic from affected ONU to its backup ONU in case of failure.