Patent ID: 8351602

Claim:
A dual-mode wireless sensor network system, comprising: at least one local wireless sensor, for detecting an abnormal state of an environmental event and transmitting an abnormal event message; a local event processing device, for receiving the abnormal event message from the local wireless sensor, wherein the local wireless sensor cooperates with the local event processing device to establish a regular mode key; and at least one remote event processing device, for receiving the abnormal event message from the local wireless sensor, wherein the local wireless sensor cooperates with the remote event processing device to establish a special mode key, wherein the local wireless sensor encrypts the abnormal event message related to the abnormal state with the regular mode key and transmits the encrypted abnormal event message to the local event processing device when the local wireless sensor detects the abnormal state, and the local wireless sensor encrypts the abnormal event message related to the abnormal state with the special mode key and transmits the encrypted abnormal event message to the remote event processing device when the local wireless sensor does not receive a response message from the local event processing device, wherein the remote event processing device comprises a plurality of neighbor event processing devices and the special mode key comprises a cooperative mode key, the local wireless sensor initiates the establishing of the cooperative mode key with the neighbor event processing devices by issuing a key establishing request to the communicable neighbor event processing devices via the local event processing device, sequentially cooperates with the neighbor event processing devices to establish the cooperative mode key according to the numbers of communicable neighbor wireless sensors between the local wireless sensor and the neighbor event processing devices; and when the local wireless sensor does not receive a response message from the local event processing device, the local wireless sensor encrypts the abnormal event message related to the abnormal state with the cooperative mode key and transmits the encrypted abnormal event message to the neighbor event processing devices based on an order of establishing the cooperative keys between the local wireless sensor and the neighbor event processing devices.