A monitoring system is provided with a two tier communication network. Multiple first tier nodes comprising wireless or RF sensors are each equipped with transceivers operating at a first, low power level. Multiple second tier nodes are spaced to communicate with selected sensors at the lower bandwidth level, and also communicate with each other at a higher power level and higher bandwidth, to route sensor communications to a central controller. The sensors comprise standard home and small business sensors such as motion detectors, glass breakage, pressure, temperature, humidity and carbon monoxide sensors to name a few, each equipped with a transceiver. The sensors are placed throughout a structure to be protected or monitored. Since such structures can be quite large, several second tier routers are provided such that at least one is within range of each sensor to receive its low power signals. A routing table is dynamically generated to direct communications between routers and the controller