X10 Automation and ZigBee Networks

The history of home automation is quite interesting. A number of years ago, the only remote control that most people owned was the remote control to their television. Remotes have since come a long way. Now we can control lights, garage doors, and CD players. Instead of standing up and walking over to the television to change the channel, we rely on a remote so that we can stay seated and relaxed. Instead of getting out of the car and lifting the garage door, we press a button and it opens. The problem with all these remotes is simply that; all these remotes! There are simply too many individual remotes. This is precisely the problem ZigBee Networks was created to solve. ZigBee is a wireless home-area network that is cost-effective and based on standards. It supports low data rates and it consumes very little power. The network is very reliable and secure. 

 

Zigbee wireless operates in two modes: Beacon mode and non-beacon mode. In beacon mode, all devices are coordinated with each other and they know exactly when to communicate with one another. When the network is in this mode, the network coordinator will, “wake up” and send out a beacon. The beacon wakes up each device, which in turn will determine if it has any commands to receive and execute. If the device has a command, it will execute the command, and return to sleep. If it does not have a command, the device will immediately go back to sleep. When all is said and done, the network coordinator will return to sleep. In non-beacon mode however, all of the devices are able to communicate with the network coordinator at any time. This can sometimes lead to devices confusing signals, or interrupting other signals. Also, the network coordinator must be awake at all times in order to communicate with all of the devices, which leads to more energy usage. Either way, Zigbee’s low energy consumption stems from the ability of the network to remain inactive over considerable periods of time. 

 

The closest competitor to ZigBee is Bluetooth. Much research has been done trying to determine if the two technologies go well together, or if they are competing automation systems. Giving the two technologies a quick glance however, it seems that they are quite complimentary of each other. ZigBee is focused on remotely controlling devices, and automating simple processes. Bluetooth is designed to with connectivity between large-packet devices such as cell-phones. ZigBee does not use much power; therefore users generally just throw in a few batteries and forget about it. Bluetooth on the other hand, relies on battery recharges, and a lot of them. When responding to devices, ZigBee is very quick to respond. Bluetooth is exactly the opposite. Bluetooth takes a fair amount of time to respond. This means that the two technologies complement each other quite nicely, and they can be used together with relative ease.

In summary, ZigBee is used to automate many, small tasks using as little energy as possible. Despite these facts, ZigBee is very reliable, and is a highly recommended security network.