ZigBee protocol stack overview Embedded Systems Software Training Center ZigBee protocol stack overview COPYRIGHT © 2012 DSR CORPORATION 1 1 1

Assumptions for Using this Teaching Material DSR and OTSL takes no responsibility about the problem which occurs as a result of applying the technical information written in this document in a commercial product, although the information is based on actual implementation and our experiences, is reliable enough. COPYRIGHT © 2012 DSR CORPORATION 2 2 2 2 2

Agenda Basic ZigBee overview 802.15.4 basics Architecture of Zigbee ZigBee Profiles Historical necessity of ZigBee Technical trend and application examples of ZigBee COPYRIGHT © 2012 DSR CORPORATION 3 3 3

Objectives Understand 802.15.4 basics Understand Zigbee basics and applications Understand Zigbee basic architecture Understand Zigbee most common issues. COPYRIGHT © 2012 DSR CORPORATION 4 4 4

Basic ZigBee Overview COPYRIGHT © 2012 DSR CORPORATION 5 5 5 5

Basic ZigBee overview ZigBee is a specification for a high level protocol stack using small, low-power and low-cost radios. It based on IEEE 802.15.4 standard for Personal Area Network. ZigBee standard maintained be ZigBee Alliance (www.zigbee.org) Usually vendors of ZigBee devices use system-on-chip (SoC) solutions with integrated radio and 60-250KB of flash memory. ZigBee data transmission rate varies from 20 to 900kbits. For non-commercial purposes, the ZigBee specification is available free to the general public. An entry level membership in the ZigBee Alliance ( Adopter ), provides access to draft specifications and permission to create products for market using the specifications. The requirements for membership in the ZigBee Alliance causes problems for open-source developers because the annual fee conflicts with the GNU GPL COPYRIGHT © 2012 DSR CORPORATION 6 6 6 6 6

802.15.4 basics IEEE 802.15.4 specifies physical and MAC layer of low- rate WPANs. It could be and it used as a basis for different protocols and standards. ZigBee, ISA100.11a, MiWi etc. IEEE 802.15.4 specification: 802 = networking group 15 = wireless network 4 = low data rate consuming less power COPYRIGHT © 2012 DSR CORPORATION 7 7 7 7

802.15.4 basics It operates one of the following bands: 868.0-868.6 MHz: Europe, allows one communication channel 902-928 MHz: North America, up to ten channels (2003), extended to thirty (2006) 2400-2483.5 MHz: worldwide use, up to sixteen channels (2003, 2006) COPYRIGHT © 2012 DSR CORPORATION 8 8 8 8

802.15.4 basics COPYRIGHT © 2012 DSR CORPORATION 9 9 9 9

802.15.4 basics It could use both amplitude and phase keying Has guaranteed time-slots. Uses network beaconing. Has no routing mechanism, so, only star and peer-to- peer allowed. And the main: Most of the applications often uses only part of 802.15.4 that is suitable for their purposes. COPYRIGHT © 2012 DSR CORPORATION 10 10 10 10

ZigBee Architecture COPYRIGHT © 2012 DSR CORPORATION 11 11

ZigBee Architecture COPYRIGHT © 2012 DSR CORPORATION 12 12 12 12

ZigBee Architecture Full Function Device (FFD) ■ Capable of being the PAN Coordinator ■ Implements processing of “Association Request” ■ Implements processing of “Orphan Notification” ■ Implements processing of “Start Request” ■ Implements processing of “Disassociation Notification” Reduced Function Device (RFD) ■ Can only associate and communicate with a FFD ■ Reduced stack removes optional components COPYRIGHT © 2012 DSR CORPORATION 13 13 13 13

Architecture of ZigBee Mac layer: controlling media, basic rf transmitting/receiving. Network (NWK) layer: Routing, addressing, discovery and join. APS layer: Bridge between NWK and upper layers. Binding tables, separate addressing scheme etc. ZDO layer: Different OTA stack parameters management. Application/Profiles: Profiles and customer's application. COPYRIGHT © 2012 DSR CORPORATION 14 14 14 14

Architecture of ZigBee The IEEE 802.15.4 PHY layer includes features such as receiver energy detection (ED), link quality indication (LQI) and clear channel assessment (CCA). The network addressing follows 64-bit IEEE and 16-bit short addressing, supporting over 65,000 nodes per network. The IEEE 802.15.4 MAC sub layer controls the access to the radio channel using unslotted CSMA-CA (Carrier Sense Multiple Access with Collision Avoidance) method. It is also responsible for flow control via acknowledgement and retransmission of data packets, frame validation, and network synchronization as well as support to upper layers for robust link operation. peer entity control transfers. COPYRIGHT © 2012 DSR CORPORATION 15 15 15 15

Mac Layer The IEEE 802.15.4 MAC defines four frame structures: The MAC frame structure has been designed to keep the complexity to a minimum while making the system sufficiently robust for transmissions on a noisy channel. The IEEE 802.15.4 MAC defines four frame structures: · A beacon frame, used by a coordinator to transmit beacons. · A data frame, used for all transfers of data. · An acknowledgment frame, used for confirming successful frame reception. · A MAC command frame, used for handling all MAC COPYRIGHT © 2012 DSR CORPORATION 16 16 16 16

NWK Layer NWK layer handles network addressing and routing by invoking actions from MAC layer. Starting the network. Assigning network addresses. Adding/removing devices to/from network. Routing messages to the intended destination Applying security to the incoming/outgoing messages. Discovery and store routing information COPYRIGHT © 2012 DSR CORPORATION 17 17 17 17 17

APS Layer APS layer responsible for communication with relevant applications and endpoints. As well as for managing binding table. Here's significant application concepts: A node may have several applications running on it - for example, a node in an environment monitoring network may be measuring temperature and humidity, each of which is an application. These application instances on a node are said to be endpoints, where messages can originate and terminate. In order to route messages arriving at the node to the appropriate application, each application on the node must be uniquely identified and is given an endpoint address. Endpoint addresses for user applications are numbered from 1 to 240. Therefore, to identify a particular application instance in a ZigBee network, you need to supply the relevant network address and then the required endpoint address on the node. Endpoint address 255 can also be used. This is the broadcast endpoint address COPYRIGHT © 2012 DSR CORPORATION 18 18 18 18 18

ZigBee Cluster Library (ZCL) Cluster is a structure of message or the message itself. Most of the clusters have pair. For example for input and output messages. ZigBee cluster library, a set of common clusters and attributes used across multiple application profiles. COPYRIGHT © 2012 DSR CORPORATION 20 20 20 20

ZDO Layer Endpoint address 0 on each node is reserved for a special application called the ZDO (ZigBee Device Objects). This application has a number of roles, including defining the type of node (Co-ordinator, Router or End Device), initialising the node and participating in network creation. COPYRIGHT © 2012 DSR CORPORATION 21 21 21

ZigBee Application Profiles COPYRIGHT © 2012 DSR CORPORATION 22 22

Application Profiles Every data request in ZigBee is sent (and received) on an Application Profile. Application Profile IDs are 16-bit numbers and range from 0x0000 to 0x7fff for public profiles and 0xbf00 to 0xffff for manufacturer-specific profiles. Think of a profile as a domain space of related applications and devices. Public profiles are those specified by the ZigBee Alliance (as opposed to private profiles specified by individual OEMs). Nearly all public profiles use the ZigBee Cluster Library, so I'll leave the example and details to Chapter 6, "The ZigBee Cluster Library." COPYRIGHT © 2012 DSR CORPORATION 23 23 23 23 23

Application Profiles The current list of application profiles either published, or in the works are: Released specifications ZigBee Home Automation ZigBee Smart Energy 1.0 ZigBee Telecommunication Services ZigBee Health Care ZigBee RF4CE - Remote Control Specifications under development ZigBee Smart Energy 2.0 ZigBee Building Automation ZigBee Retail Services ZigBee Light Link . COPYRIGHT © 2012 DSR CORPORATION 24 24 24 24 24

Historical necessity of ZigBee COPYRIGHT © 2012 DSR CORPORATION 25 25 25 25

Why ZigBee? Mesh Networking Technology Open Global Standard Self-healing mesh networks Low cost, long battery life, good range, secure Open Global Standard 2.4GHz is unlicensed, available Worldwide Anyone can join the ZigBee Alliance Where can ZigBee fit? Secure, reliable, Personal Area Networks for sensor, control and low bandwidth data communications. It’s a low power wireless technology that's ideal for new and old infrastructures. It can have range between 10m and 2km (with PA) Scalable Networking solutions COPYRIGHT © 2012 DSR CORPORATION 26 26 26 26 26

Bluetooth vs. WiFi vs. ZigBee vs. Others COPYRIGHT © 2012 DSR CORPORATION 27 27 27 27 27

Application Examples ZigBee is well suited for a wide range of control uses in just about any market. The Alliance has focused its standards development efforts around the commercial, residential, energy, consumer and industrial sectors. It has developed global standards for energy management and efficiency, home and building automation, health care and fitness, telecom and consumer electronics. Here are just a few examples of what our standards control: Demand Response Advanced Metering Infrastructure Automatic Meter Reading Lighting controls HVAC control Heating control Wireless smoke and CO detectors Home security Blind, drapery and shade controls Medical sensing and monitoring Remote control of home entertainment systems Indoor location sensing Advertising on mobile devices COPYRIGHT © 2012 DSR CORPORATION 28 28 28 28

Technical Trends The main trend in Zigbee development is improving power management and stack interoperability. These features called Smart Energy 2.0. The Smart Energy 2.0 effort was launched in 2008 to offer IP-based HAN functionality. It will address the following emerging market requirements: Deployments in multi-dwelling units Support multiple Energy Service Interfaces into a single premise Supports any transport layer based on IETF IP compliant standards, including but not limited to ZigBee IP, other RF-based and Power Line Carrier (PLC)-based transports Support internationally recognized standards to ensure long-term interoperability with multiple technologies Accomplishing these goals has led to the adoption of networking standards that ensure interoperability between ZigBee and other network technologies. The ZigBee Alliance is developing an internet protocol (IP) networking layer called ZigBee IP, which is based on the IETF-based 6LoWPAN technology. The application clusters for Smart Energy 2.0 have been mapped to the IEC Common Information Model, that will be implemented in Smart Energy 2.0. This provides a migration path for features defined in ZigBee Smart Energy 1.X to be supported in Smart Energy 2.0. COPYRIGHT © 2012 DSR CORPORATION 29 29 29 29

Technical Trends The ZigBee home area network standard already has lots of challengers (Z- Wave, Wi-Fi, and HomePlug to name just three). Now it faces an assault from the biggest, baddest billion-dollar bully of them all – Google. Google recently announced it will create its own home networking standard as part of its Android@Home initiative COPYRIGHT © 2012 DSR CORPORATION 30 30 30 30