ULPW technology

ULPW (Ultra Low Power Wireless) technology allows for data radio communication amongst two or more electronic devices with the following features:

• minimal data volume exchange;
• the power consumption of the radio, and often of the whole electronic device, is very low (non-rechargeable battery expected life is measured in years);
• ranges vary from roughly a hundred feet, for non-amplifier radio, to more than one thousand feet for amplified ones; coverage can be further extended using special radio techniques or packet bouncing on intermediate nodes.

ULPW technology is particularly suitable for the implementation of radio sensors' networks (Wireless Sensor Network) in which sensored, battery-powered nodes have a very long operative life thanks to power consumption reduction techniques. Often it can be compared to the product's life in the specific application.

In more common applications, a heterogeneous set of sensored nodes placed in the most suitable locations, acquire the required information and transmit them by radio to the collecting node which, depending on the application, can be:

• a wall-mount processor or desktop console which autonomously processes the information received from the sensors
• a wall-mount processor or desktop console which operates as a bridge and passes the received information to the user system via LAN or wide area network
• a handheld terminal with which information provided by the sensors are collected, when needed.

Other type of applications exist where the sensored nodes are mobile, while the collecting nodes can be in turn either stationary or mobile. In these applications, usually, mobile nodes' power consumption is not negligible. Therefore it is preferred to use rechargeable, bigger batteries.

Thanks to the availability of the battery, sensored nodes can operate as data loggers, thus acquiring and storing data even when the radio network is not present or operative.

In some applications (remote control and home automation) nodes are supplied by the mains network, therefore they can operate as actuators or sensors/actuators nodes.

 

IEEE 802.15.4 and ZigBee standards

In the scenario of the various ULPW solutions for RF circuitry and antennas, used frequencies, modulation techniques, low-level protocols and channel access, network protocols, network lock-in policies, consumption policies, we highlight two very interesting standards for adopted solutions but just for the fact they are internationally recognized standards.

IEEE 802.15.4 is a standard emitted by the Institute of Electrical and Electronics Engineers (IEEE) which defines the physical layer and the low-level protocols for digital radios – low power and low baud rate – which operate in the radio frequency ranges assigned to industrial, scientific and medical usage (ISM bands): 868MHz in Europe, 915MHz in United States and 2.4GHz in almost all the world.

ZigBee is a standard by ZigBee Alliance which includes a set of high-level communication protocols for digital radios based upon IEEE 802.15.4 standard. Its purpose is to reduce nodes' complexity and cost in a WPAN (Wireless Personal Area Network).

There are several ULPW applications based upon IEEE 802.15.4 and Zigbee technologies. These are for example (from experience and concepts by TERTIUM Technology):

• monitoring of cracking or other similar damages in buildings showing similar crisis areas
• check for presence in port, and correct moorage, of yachts during wintering
• remote control of anti-trespassing systems in homes
• back-order of meals and beverages by customers in fast-foods