| Wireless technologies such as ZigBee provide | | | | The SAS itself includes the following attributes: |
| many benefits, but they also present unique | | | | - The startup control, explained below |
| challenges when it comes to installation and | | | | - The Extended PAN ID (or EPID) of the network |
| commissioning. In a wired network, you can follow | | | | (a globally unique network identifier) |
| the wires to determine which switch is controlling | | | | - The channel mask, which determines which |
| which lights. When there are no wires, you need a | | | | channels the device should scan for a network to |
| different methodology and set of tools to get the | | | | join |
| network to operate the way you want it to. | | | | - Security information, such as the network key |
| A standards-based protocol such as ZigBee offers | | | | and the address of the trust center |
| obvious and significant benefits--interoperable | | | | The startup control is used to determine how the |
| building blocks, a wider range of options to | | | | device should join the network: |
| application developers, and no danger of | | | | - As a coordinator, and hence start the network |
| obsolescence due to the use of proprietary | | | | with the attribute values provided |
| methods and solutions. | | | | - Join any network |
| In addition to a standards-based protocol, the | | | | - Rejoin the network with a specific EPID |
| ZigBee Alliance has and continues to deliver on | | | | - Assume that it is already a part of a network |
| standards-based commands and methodology for | | | | with specific setting values (sometimes known as |
| commissioning ZigBee systems. These will ensure | | | | the connected startup mode) |
| that tools and devices can interoperate by using | | | | As an example, a device with the following SAS |
| the same over-the-air commands. | | | | values has the greatest flexibility in being able to |
| Within the ZigBee framework, there are three | | | | join any network (but correspondingly, has the |
| broad classes of parameters that can be | | | | greatest risk of joining the wrong network): |
| commissioned: | | | | - Join any network |
| - Membership, which encompasses all aspects of | | | | - With a channel mask allowing joining on "all |
| how networks and devices determine which | | | | channels" |
| devices are included (or excluded) from a specific | | | | - No security key |
| network | | | | Security is an important part of ZigBee, since it |
| - Groups & Bindings, which encompasses all | | | | provides the means to prevent unwanted |
| aspects of how devices in the same network are | | | | monitoring of the system by encrypting all packet |
| logically connected to each other, or belong in | | | | communication in highly secure 128-bit AES |
| groups where logical one-to-many or | | | | protocols. |
| many-to-many connections are required. | | | | One important requirement to delivering such as a |
| - Application, where application-specific settings | | | | secure system is the commissioning of security |
| (such as thermostat levels or schedules for when | | | | keys. In addition to ensuring that devices have |
| lights come on) are set. | | | | the right keys to encrypt and decrypt packet |
| These classes of parameters are also | | | | exchanges, security can also used to exclude |
| commissioned in sequence. Membership occurs | | | | devices from a network (as a part of |
| first, to ensure that devices join and form the | | | | membership commissioning). |
| correct network. Groups and bindings ensure that | | | | ZigBee Device Profile |
| the devices can connect to the right devices | | | | The ZigBee Device Profile (ZDP) provides a suite |
| within this network. And finally, the application | | | | of standard commands that can deliver (or assist) |
| settings are commissioned to ensure correct | | | | in commissioning in the following ways: |
| application behavior. | | | | - ZDP Binding and Group Managers offer all the |
| All the commands required to achieve Membership | | | | necessary commands to deliver binding and group |
| and Groups & Bindings commissioning can be | | | | commissioning. |
| found in the ZigBee Commissioning Cluster and | | | | - Other ZDP management commands may be |
| ZigBee Device Profile. | | | | beneficial in assisting in commissioning. For instance, |
| ZigBee Commissioning Cluster | | | | the ZDP Network and Service Discovery |
| The ZigBee Alliance has specified a commissioning | | | | commands can be used to examine the network |
| cluster, which delivers a standard set of | | | | and devices to make commissioning decisions. The |
| over-the-air ZigBee commands for membership | | | | ZDP Node Manager can be used to control "Permit |
| commissioning. | | | | Join" and issue "Leave" commands to more |
| The key command used to achieve membership | | | | directly manage membership. |
| commissioning is the Restart Device Request | | | | Conclusion |
| command. This command, which can be sent by | | | | In a perfect world, devices would commission |
| either a commissioning tool or through another | | | | themselves. You would simply power them up, |
| device (such as the coordinator, or a gateway for | | | | turn them on, and then stand back and watch the |
| remote commissioning), instructs a device to | | | | devices work out which network they should join, |
| restart with a specific set of startup attributes. | | | | how security worked in that network, which |
| It is important to note that a complete set of | | | | device (or devices) they should bind to, and which |
| such attributes (called a startup attribute set or | | | | devices they should communicate with. |
| SAS) will determine how a device starts up and | | | | Until that perfect world arrives, you can take |
| chooses to join a network to join. The SAS can | | | | advantage of the standards-based commissioning |
| be commissioned into a device at the installation | | | | features provided by the ZigBee Alliance to help |
| site, but by definition, an SAS already exists | | | | and make the job a whole lot easier. |
| (pre-programmed) in the device before it arrives. | | | | |