By pressing the menu button within Android's Wi-Fi settings menu, you should be able to access an Advanced settings sub-menu.
When this feature is turned on, your phone will notify you when an un-protected Wi-Fi network is available in the area. It will then give you the option to connect to the network.
Un-protected Wi-Fi networks require no password or other secret credentials to access. Unfortunately, this is also a security risk.
Connecting to any Wi-Fi network gives the owner of that network the potential to monitor your activity online. For security reasons it is a good idea to connect only to Wi-Fi networks operated by people you trust.
Blocked open networks
A feature only found on some devices, this allows you to maintain a list of open networks that you do not want to be notified about, and do not want to connect to. This feature probably does not make sense if you do not use the above Network notification option.
As stated in the previous section, connecting to Wi-Fi networks owned by people you do not trust is a security risk.
Keep Wi-Fi on during sleep
This setting controls whether Wi-Fi should be deactivated while the phone is in sleep mode - that is, while the screen is off. The options may consist of:
- Only when plugged in
- Never (increases data usage)
In recent versions of Android this usually defaults to "Always", meaning that Wi-Fi should remain enabled while the device is asleep.
Wi-Fi connections usually do not consume much battery while a phone is asleep. If the phone needs to communicate over the Internet while it is asleep, it usually requires less battery power to transfer that data over Wi-Fi than over your mobile carrier's network. It is also likely to cost less, too, as mobile data counted by your carrier can be more expensive.
Note that if you set this to "Never", Wi-Fi usually still remains on for approximately 15 minutes after turning your device's screen off, rather than turning off immediately.
Wi-Fi frequency band
This feature is only found on some devices and can enable or disable modes of Wi-Fi communication.
Different standards exist for Wi-Fi communication, commonly referred to by letters such as "A", "B", "G", "N", and "AC", with "N" and "AC" the most common standards currently in use. "B" and "G" operate in the 2.4 GHz radio band, while "A" and "AC" operate in the 5 GHz band. "N" is unique in that it can be configured to operate on either band, depending on how the access point is set up.
This feature allows you to enable and disable the 2.4GHz and 5GHz bands independently. This has consequences for which Wi-Fi networks you'll be able to connect to and which of the Wi-Fi standards you'll be able to use. It should be safe to leave this setting at its default, allowing operation on either band.
If you know you will only be connecting to Wi-Fi networks on a particular band, it is safe to disable the other band. This may theoretically save some battery life, though the saving is likely to be negligible. This may also be used to force communication to a particular band, particularly when you don't have control over the Wi-Fi access point / router.
This device-specific option enables a low-power Wi-Fi mode, that sacrifices some Wi-Fi performance for the ability to save battery life.
Specifically, this increases the DTIM Interval, which specifies how often Wi-Fi devices and access points communicate with each other to indicate whether there is data waiting to be transferred.
The change to the DTIM interval is believed to only apply while the device is in sleep mode (screen off) so it should not impact performance while using the device.
Best Wi-Fi performance
Information about this device-specific option is difficult to find, except that it reportedly significantly increases battery drain, even while the device is asleep, for little noticeable increase in performance. It is recommended to always keep this option disabled, if your device has this option.
This is a read-only field intended only to show you the MAC address of your device's Wi-Fi network adapter.
The purpose of a MAC address is to uniquely identify a network adapter using a code that is unique to that adapter. It can be used by some computer networks to implement access control allowing only certain network adapters to connect.
You would not normally be expected to need this address unless the administrator of a network needs it from you.
This is also a read-only field, only intended to show you the current IP address for your Wi-Fi connection. Unlike the MAC address, the IP address can change between different Wi-Fi connection sessions.
The IP address for your device is usually assigned by the network you have connected to.
You would not normally be expected to need this address unless you need it for a particular communication purpose.
Check for Internet service
If this device-specific option is enabled, every time your device connects to a Wi-Fi network it will check to ensure that the Wi-Fi network allows access to the Internet. If a connection to external servers on the Internet cannot be established, you will receive a notification message on your device informing you that the Wi-Fi network you have connected to does not currently have Internet access.
This feature can be useful in troubleshooting potential problems with the network you are connecting to via Wi-Fi. Specifically, it can be used to alert you when the Wi-Fi access point exists and is working, but its path out to the wider Internet is not available.
If you regularly connect to Wi-Fi networks that are not connected to the Internet, or may not always be connected to the Internet, this option may quickly become annoying.
Some devices may provide a feature enabling you to enable Wi-Fi at certain times of the day and disable it at other times.
This can be helpful if you know that during certain times, you will not be near a usable Wi-Fi network, and you would like to save battery power. Note that on modern devices the saving in battery power is likely to be negligible.