Cognitive Wireless Router (CWR) system developed by NICT using the cognitive radio technologies were deployed in the disaster area of the great earthquake hit east of Japan in March 11, 2011. Totally 68 units of the CWR were deployed in evacuation sites, volunteer centers, hospitals, disaster headquarters, temporary housings, and so on. The system was operated for 2 years according to strong requests from the local governments. During the operation, the CWRs continuously and automatically selected the best Wide Area Network (WAN) at its location to access the Internet and provided Wireless LAN (WLAN) to people there. The authors themselves went to the disaster area, installed the CWRs, saw their utilization and asked opinions. Based on these experiences through the restoration activity, this paper notes the lessons from the earthquake. Also, a wide area mesh network WLAN infrastructure which has been newly developed according to the lessons is introduced.