The Canon Professional Network has published
a fairly lengthy explanation of the use of Canon Wireless File Transmitter units such as the WFT-E5 and its predecessors, the WFT-E2/E3/E4. These transmitters can transfer images over WiFi networks from compatible Canon DSLR cameras to a computer, as well as enable certain other features.
The article covers network types, communication modes, camera and software configuration, using Wi-Fi in the studio and other topics.