[WSN] Which wireless technologies are used in Wireless Sensor Networks?

There are many different wireless technologies used for Wireless Sensor Networks (WSN) in the world today, based on the specific needs, availability of power (battery driven or not), local radio frequency regulations, density of sensors, distance to the sensor, how often sensors need to be read, the amount of data, the infrastructure, etc.

Radiocrafts offer a broad range of solutions for WSN, each with their unique properties to fit the needs of each particular situation. Some solutions are based on proprietary communication protocols, and others are based on industry standards. Among the standardized protocols we find Wireless M-Bus, KNX RF Multi, ZigBee and 6LoWPAN-based solutions (Wi-SUN and ZigBee IP). As for proprietary protocols we offer point-to-point, point-to-multipoint, multi-hop (RC232) and mesh (Tinymesh).

Wireless M-Bus and KNX RF Multi are standards optimized for battery operation. The most common operating frequency is 868 MHz, giving better range than solutions based on 2.45 GHz. KNX RF can also be operated at 433 MHz, while Wireless M-Bus also offer a narrowband option at 169 MHz giving the best range of any technology. The data rate is limited (2.4 – 67 kbps depending on mode) and not intended for large data transfer. Wireless M-Bus can be used with single hop repeaters, and KNX RF with multi-hop repeaters.

RC232 is a transparent protocol that can be used for any UART based communication as a “cable replacement”. Because this protocol can run on all module platforms, there is a wide choice of radio frequencies and data rates to meet any specific application. A static multi-hop feature can be used to extend the range.

ZigBee and Tinymesh are mesh protocols that increase coverage by using the mesh nodes as “step-stones”. ZigBee operates at 2.45 GHz, which gives a shorter range than sub-1GHz, but because of the mesh the coverage can be good and reliable with redundant paths, as long as there are enough nodes in the network. An advantage is that 2.45 GHz is a world-wide license free frequency. Tinymesh can run on most module platforms, so there is a wide choice of radio frequencies and data rates to meet any specific application. These mesh protocols need constant power for the routers, and are therefore not suitable for battery operation.

IEEE 802.15.4 based protocols in combination with 6LoWPAN will give a standard based IPv6 system. The well-known concepts used in Internet IP communication is then extended all the way to the sensor nodes, providing a seamless operation with the rest of the IP world. Implementation of an IP stack takes more resources, and hence these solutions tend to be higher cost than the simpler protocols.

Unique features such as pulse counting inputs and sensor interfaces makes it very easy to build a complete wireless sensor. Our family of ultra narrowband modules provides the best performance in terms of radio range and noise immunity, which can be of importance in industrial environments. Our multi-hop (RC232) and mesh solutions (Tinymesh and ZigBee) can be used to cover a large area with multiple sensors. 6LoWPAN is a technology that enables IPv6 communication all the way to the end node, for seamless integration with the internet. And the Sigfox modules are the solution for mobile sensors, or sensors that are installed throughout a city or even larger geographical areas.

Last Update: November 2, 2017  

February 20, 2017   6315    Wireless Sensor Networks