Wireless Sensor Networks

My friend asked me to publish this article. He does not have an account on Habré, but he would very much like to receive an invite. The author received an invite - axel2001 All the pluses to him.
Thanks for the invite - tar

I want to devote my article to wireless sensor networks technologies, which, as it seems to me, are undeservedly deprived of the attention of the habr community. The main reason for this, I see, is that the technology has not yet become widespread and, for the most part, is more interesting to academic circles. But I think in the near future we will see many products, one way or another based on the technologies of such networks. I have been engaged in research on sensor networks for several years, wrote a dissertation on this topic and a number of articles in Russian and foreign journals. I also developed a course on wireless sensor networks, which I taught at the Nizhny Novgorod State University (I don’t provide a link to the course, if you are interested, I can give a link in private). Having experience in this field,

General information

Wireless sensor networks have been greatly developed recently. Such networks, consisting of many miniature nodes equipped with a low-power transceiver, microprocessor and sensor, can connect global computer networks and the physical world together. The concept of wireless sensor networks has attracted the attention of many scientists, research institutes and commercial organizations, which has provided a large flow of scientific work on this topic. Great interest in the study of such systems is due to the wide possibilities of using sensor networks. Wireless sensor networks, in particular, can be used to predict equipment failure in aerospace systems and building automation. Due to its ability to organize itself, autonomy and high fault tolerance, such networks are actively used in security systems and military applications. The successful use of wireless sensor networks in medicine for health monitoring is associated with the development of biological sensors compatible with integrated circuits of sensor nodes. But the most widespread wireless sensor networks are in the field of environmental monitoring and living things.

Iron

Due to the lack of clear standardization in sensor networks, there are several different platforms. All platforms meet the basic basic requirements for sensor networks: low power consumption, long operating time, low-power transceivers and the presence of sensors. The main platforms include MicaZ, TelosB, Intel Mote 2.

MicaZ

• Microprocessor: Atmel ATmega128L
• 7.3728 MHz frequency
• 128 KB flash memory for programs
• 4 kb SRAM for data
• 2 UART's
• SPI bus
• I2C bus
• Radio: ChipCon CC2420
• External flash memory: 512 Kb
• 51-pin additional connector
• eight 10-bit analog I / O
• 21 digital I / O
• Three programmable LEDs
• JTAG port
• Powered by two AA batteries

TelosB

• Microprocessor: MSP430 F1611
• 8 MHz frequency
• 48 KB flash memory for programs
• 10 KB RAM for data
• UART
• SPI bus
• Built-in 12-bit ADC / DAC
• DMA controller
• Radio: ChipCon CC2420
• External flash memory: 1024 Kb
• 16-pin additional connector
• Three programmable LEDs
• JTAG port
• Optional: Sensors of light, humidity, temperature.
• Powered by two AA batteries

Intel Mote 2

• 320/416/520 MHz PXA271 XScale microprocessor
• 32 MB Flash
• 32 MB RAM
• Mini-USB interface
• I-Mote2 connector for external devices (31 + 21 pin)
• Radio: ChipCon CC2420
• LED indicators
• Powered by three AAA batteries

Each platform is interesting in its own way and has its own characteristics. Personally, I had experience working with TelosB and Intel Mote 2 platforms. Also, our own platform was developed in our laboratory, but it is commercial and I can’t talk about it in detail.

The most common 3 years ago was the use of the CC2420 chipset as a low-power transceiver.

Software and data transfer

The main data transmission standard in sensor networks is IEE802.15.4, which was specially developed for wireless networks with low-power transceivers.

There are no software standards for sensor networks. There are several hundred different protocols for processing and transmitting data, as well as node management systems. The most common operating system is the open source system - TinyOs (being at Stanford University, I personally met one of the developers). Many developers (especially commercial systems) write their control system, often in Java.

The touch node management program running the TinyOs operating system is written in nesC.

It should be noted that due to the high cost of equipment and the complexity of setting up sensor networks, various modeling systems, in particular the TOSSIM system, specially designed to simulate the operation of nodes running TinyOs, are widely used.

Conclusion

Sensor networks are becoming increasingly common in Russia. When I started to deal with them in 2003, the number of people in Russia who were familiar with this technology could be counted on the fingers. Including in Russia, the well-known Luxsoft Labs was engaged in this.

I have been working with sensor networks for 6 years and I can tell a lot about these technologies. If the Habrasociety is interested and I have the opportunity, then I will be happy to write a series of articles on this topic. I can touch upon such things as: real work with the TmoteSky platform, features of programming for the TinyOs system in nesC, original results of studies obtained in our laboratory, impressions of 1.5 months of work at Stanford University, in the project on touch networks.

Thank you all for your attention, I will be happy to answer your questions.