Enormous and long-term data is crucial to make structural health monitoring practical. To collect huge and high-quality data for structural health monitoring, we are constructing a wireless communication system featuring: (1) low-jitter distributed synchronized sampling which enables users to accurately compare data from different points, (2) high-throughput collection which reduces data collection time, and (3) low-power multi-hop communication which enables permanent deployment with no external power supply. In addition, we are working on implementing several monitoring systems where we comprehensively consider not only the communication method, but also sensor selection, casing, and event detection schemes. Specifically, we are developing an elevated highway monitoring system which has recorded acceleration data over several years, a cable-stayed bridge monitoring system which estimates cable tension, and an earthquake monitoring system which estimates building story drift. Also, we are analyzing a cumulative total of about 1,500 days of the acceleration data in six bridges.