Alan Ott, founder of Signal 11 Software, gives a presentation dealing with wireless networking for the internet of things in Linux, especially with 802.15.4 and 6LoWPAN standards at the Embedded Linux Conference in Barcelona, Spain on November 5, 2012.
With the rise of the internet of things, low-power wireless devices will become increasingly prevalent. IEEE 802.15.4 is a wireless networking protocol designed for low-power and low-data-rate devices, such as those used in wireless sensor networks. While some higher layer protocols based on 802.15.4 are proprietary, an open standard called 6LoWPAN enables IPv6 traffic over 802.15.4. This presentation will give overviews of 802.15.4, its status in the Linux kernel, hardware support, comparison with other wireless protocols, and a demonstration of a simple 802.15.4/6loWPAN network.
This presentation is targeted toward developers who wish to create low-power, low-data-rate wireless networks for sensors or other applications. Attendees can expect to gain a basic understanding of 802.15.4 and 6loWPAN and also gain some ideas for use in their own systems. Technical expertise required is low.
Alan talk covers the following main items:
- IEEE 802.15.4 Introduction:
- Standard for low-power, low data rate wireless communication between small devices.
- It’s not Zigbee which sits on top of 802.15.4 (OSI Level 3 vs OSI Levels 1 & 2). Zigbee license conflicts with the GPL and can’t be implemented in the Linux kernel.
- 802.15.4 can operate on 2.4 GHz, 915 MHz and 865 MHz bands depending on local regulations.
- Uses – Industrial control and monitoring, wireless sensor networks, intelligent agriculture, security systems, smart grid…
- Technical details – Frame type, security, PANs, addressing, etc…
- 6LoWPAN Overview – IPv6 over IEEE 802.15.4 can provide an IP address to all small devices.
- Linux Support for IEEE 802.15.4 and 6LoWPAN with 2 kernel trees and independent projects:
- Linux-Zigbee project – 802.15.4 and partial 6LoWPAN implementation. No updates of the kernel for 6 months. The project includes user space tools (iz, izcoordinator, and izchat) and support for multiple drivers for chips from Atmel, TI, Analog Devices and Redwire.
- Linux-wsn project – Project up-to-date in mainline kernel with support for raw 802.15.4 sockets and 6LoWPAN. It uses the same user space tools as Linux-Zigbee, and provides drivers for Atmel AT86RF230, Microchip MRF24J40 and Redwire Econotag. Many things currently work, but there’s still more things to do for both 802.15.4 and 6LoWPAN implementations.
- Other Support for IEEE 802.15.4 and 6LoWPAN – Contiki OS and TinyOS,
The presentation also includes a security system demo (Alarm) with 2 nodes: A Beaglebone + Microchip MRF24J40MA + Maxbotix Ultrasonic Range Finder (HRLV-EZ0) and a laptop + Redwire Econotag.