WiFi: Does disabling SSID broadcast saves battery(ies)?

Question

I own a mobile-wifi (portable device that acts as WiFi server locally, and uses a 3G network to carry the Internet data) and needs its battery to last as much as possible.

Basically, a device (e.g. my iPhone) needs a WiFi access 10mn per hour, during the 50 remaining mn the mobile-wifi "sleeps".

But, in order to be discovered, the mobile-wifi broadcasts, by default, its own SSID every x seconds (x must be low, as it always appears quickly in the wifi servers list).

However there is a way (settings menu) to disable the broadcast. Then, in order to access the wifi server, one has to enter manually (once) the SSID and its security protocol + password.

Is it a recommended procedure? Does it increase the mobile wifi battery life?

Answer 1

This would definitely increase the battery life, but it may not be significant when other factors are considered.

The primary factors for energy usage for your mobile WiFi device would be:

• the power output setting (if it has one - some routers/devices allow it to be lowered from the default 100%).
• the type of encryption used (and whether the chipset in it provides encryption through hardware or if it's done by software, with the latter being slower and consuming more power).
• how much data is being transmitted.
• how far your iPhone is from the WiFi device. If you're closer to the WiFi device, you could have it use lesser output power and still have a good connection.

If you can, reduce the output power setting and use the iPhone physically closer to the device as much as possible. That will save a lot more energy than disabling the SSID broadcast.

Also keep in mind that disabling SSID should not to be relied on as a security mechanism. For true security, you should be using a strong encryption mechanism (like WPA2) with a strong passphrase.