1. ZigBee & TinyOS TinyOS and ZigBee are not competitive
TinyOS – Operating System, Tool Chain, Component Library
ZigBee – Hybrid-Mesh Protocol on Top of
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

2. TinyOS and Zigbee
TinyOS on MicaZ and Zigbee both use an 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

3. 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
(CC2420)

4. 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
(CC2420)

5. 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
(CC2420)

6. 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

7. 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 bytes

8. 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

9. MICAz and IEEE /ZigBee

10. 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 mW
All of PHY and part of MAC layers implemented in hardware
For more information visit:

11. 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
: 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

12. and b Channels
No overlaps with

13. 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

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