The Santander testbed is composed currently of around 2000 (projected to grow to 12,000) IEEE 802.15.4 devices deployed in a 3-tiered architecture:
•IoT node: Responsible for sensing the corresponding parameter (temperature, CO, noise, light, car presence,etc.).
•Repeaters: These nodes placed high above ground in
street lights, semaphores, information panels, etc, in order to behave
as forwarding nodes to transmit all the information associated to the
different measured parameters.
•Gateway: Devices that gather all the information
retrieved by IoT nodes and repeaters, acting as intermediate nodes
between the sensor networks and the SmartSantander backbone.