ZigBee & TinyOS TinyOS and ZigBee are not competitive TinyOS – Operating System, Tool Chain, Component Library ZigBee – Hybrid-Mesh Protocol on Top of 802.15.4 Recently Ratified Home-Automation Oriented Powered Backbone I.e., Hybrid-Mesh Crossbow is active member of ZigBee Alliance Crossbow is developing ZigBee stack on-top of X-Mesh built in nesC/TinyOS

TinyOS and Zigbee TinyOS on MicaZ and Zigbee both use an 802.15.4 physical layer RF signaling mechanisms are the same) The Zigbee Protocol Layer is being implemented in XMesh/TinyOS by Crossbow XMesh/TinyOS applications and Zigbee enabled TinyOS applications can coexist seamlessly Hundreds of TinyOS applications can tie into Zigbee networks and future Zigbee network devices can be tied into XMesh based networks

Application Support Layer XMesh Zigbee Stack App App Zigbee Device Control Implementation of standard Zigbee abstractions in the TinyOS component framework. Command and event structure of TinyOS makes applications easily to develop and highly portable. Application Support Layer Network Support Layer MAC Layer 802.15.4 (CC2420)

TinyOS XMesh Stack TinyOS apps can be written to use XMesh, Queued Send or direct Active Messages “Zigbee” is just another TinyOS Service like XMesh App App App App XMesh Multi-hop Network routing and discovery Queued Send Buffer Active Messages Delivery Layer (AM) MAC Layer 802.15.4 (CC2420)

TinyOS Routing + Zigbee Compatibility Apps can use Zigbee, XMesh, AM or a combination Bridging apps on routing nodes can route across both types of network App App App App (bridge/combine) App Zigbee Device Control XMesh Multi-hop Network routing and discovery Queued Send Buffer Application Support Layer Active Messages Delivery Layer (AM) Network Support Layer Auto-dispatch (FrameType) Dual function MAC layer 802.15.4 (CC2420)

Network Architecture XMesh Com. Zigbee Pan Com. Hybrid Mote Reliable XMesh routing links to Third-party Zigbee devices Hybrid Mote PC Hybrid Mote Hybrid Mote Hybrid Mote

Overhead for dual-function devices CPU processing: none TinyOS’s event based processing only uses CPU resources when necessary, extra protocol implementations only used when necessary Flash Memory: Size increase 8-12K RAM Memory: Size increase of 40-80 bytes

Application Interface TinyOS component model easily moves apps from basic AM to XMesh to Zigbee Simple recompile Zigbee and Active Messages provides to applications through simple event-based interface Just as an app can easily be moved from AM to XMesh, it can be easily adapted to Zigbee by using the TinyOS component model

MICAz and IEEE802.15.4/ZigBee

Main Features of the IEEE 802.15.4 Standard Data rates of 250 kbits/s in 2.4 GHz RF band 16 channels, 2 MHz wide in the 2.4 GHz ISM band CSMA-CA channel access 128 Bit AES encryption in Hardware Low power consumption CC2420: Transmit = 18 mA; Receive = 20 mA @1 mW All of PHY and part of MAC layers implemented in hardware For more information visit: www.ieee802.org/15/

802.15.4 and 802.11b Spectrum Relationship Co-exists with WiFi, Bluetooth Channel selection is important Note: Channels 25, 26 are non-overlapping 5 MHz Spacing 802.15.4: Ch. 11 to Ch. 26 Ch. 15 Ch. 20 Ch. 20 Ch. 26 2405 MHz 2480 MHz 2 MHz 802.11: Ch. 1 to Ch. 11 Ch. 1 25 MHz Spacing Ch. 6 Ch. 11 22 MHz 2412 MHz 2425 MHz 2437 MHz 2450 MHz 2462 MHz 2475 MHz

802.15.4 and 802.11b Channels No overlaps with 802.11

WiFi & 802.15.4/Zigbee Co-exitence Study Continuous data transfer on WiFi enabled Stargate Hi-power and low-power card XMesh (surge_reliable) mesh, 6 MICAz nodes measured Low-power card test

WiFi & 802.15.4/Zigbee Co-existence Study (cont’d) Low-power Card Test