Wireless sensor network

A method of updating a building sensor node of a sensor network system, the method comprising:

• executing, by the building sensor node, a first function to provide a first functionality, wherein the first function is associated with a next function identifier of a next function;
• transitioning, by the building sensor node, between a plurality of states of a state machine based on the next function identifier;
• verifying, by the building sensor node, execution of the next function by comparing the next function identifier to a table of allowed transitions;
• receiving, by the building sensor node, an additional function from a server;
• and
• updating the building sensor node to provide a second functionality to the building sensor node without rebooting the building sensor node based on the additional function received from the server.

A system of sensor nodes comprising:

• one or more sensor devices, the one or more sensor devices comprising memory configured to store instructions thereon, that, when executed by one or more processors, cause the one or more processors to:
• execute a first function to provide a first functionality, wherein the first function is associated with a next function identifier of a next function;
• transition between a plurality of states of a state machine based on the next function identifier;
• verify execution of the next function by comparing the next function identifier to a table of allowed transitions;
• receive an additional function from a server;
• and
• update the sensor device to provide a second functionality to the sensor device without rebooting the sensor device based on the additional function received from the server.