Wireless network

Both systems do not transmit continuously, but in small packages, leaving room for others to transmit.

A Wi-Fi channel can be used by several computers at (virtually) the same time.

Packages sent over the wireless Zigbee network are very small and will never compromise the throughput of a Wi-Fi system.

The wireless Zigbee network can only be compromised by the Wi-Fi system if this system is used to the absolute maximum (on all channels), leaving only little room to transmit.

As Wi-Fi channels overlap each other, it is required to select non-overlapping channels to ensure best possible communication.

Interference between overlapping channels results in lower transmission speeds or at worst no communication at all.

In a well-managed Wi-Fi system, channels 1, 6 and 11 are used to create a network with full coverage without access points interfering with each other. Using these channels also leaves gaps in the frequency band.

The wireless Zigbee network uses channels 11, 15, 20 and 25 that are positioned in the gaps of the Wi-Fi band, as shown below:

Devices using Ultra High Frequency (UHF) radio signals are sensitive to interference. However, systems using frequencies in the 2.4 GHz band are designed to coexist.

Also, for the wireless Zigbee network, the transmitting powers are significantly lower when compared to Wi-Fi, mobile telephony etc. The table shows the relation between the maximum permitted powers for several types of radio signals.

Wireless Zigbee devices (gateway, sensors and ZGPs) are guaranteed to work up to a distance of 10 m (33 ft) between the devices.
Larger distances often work depending on the environment, but are not guaranteed.

The lights of a wireless system are guaranteed to work if the distance between the light and at least one of the other lights in the network is less than or equal to 10 m. It is preferred to have at least two lights within the range of each light, as the wireless Zigbee network uses mesh routing, as shown below:

This makes the network much more robust as multiple routing paths can be used for communication.

The connection from light A to the gateway G can go via light B. If for some reason the connection between A and B is blocked, the network will automatically route the traffic through light point C.

These require the light to be installed within the reach of at least two other lights within 10 m (33 ft).

As the Zigbee Green Power devices (sensors and switches) only send messages in the Zigbee network, they exist in the network, but play no role in the routing between the wireless devices.