Data collection

Data collection is used for gathering facts, statistics and details from different sensor. During each round of data collection, the system collects data from all sensor nodes. The starting of data collection, the system and all the sensor nodes are all set in their initial State 1. Starting with the first node in the network, the system queries each node for the availability of data by sending the ‘Inquiry’ command. If the data is not ready, the sensor replies ‘Not Ready command back’; otherwise, the node replies ‘Data Ready’ and transits to State 2. After the system confirms that the data from this sensor node is ready for collection, the system transits to State 3. To request a data segment from a node, the system sends a ‘Pls Send’ command that contains a packet sequence number. One round of data collection from one sensor node is ended with a two-way handshake, where the system and the sensor exchange ‘End Transmit’ and ‘Ack End Transmit’ commands. The system then moves on to the next node and continuously collects sensor data round-by-round.