Can the Pi "official" WiFi adapter do simultaneous Client/AP modes?

Question

I want to a setup where my Raspberry Pi acts as a WiFi repeater, connecting to a WiFi network if available and rebroadcasting it's own network.

In this way, my mobile hotspot could come and go, but the home computers would always be connected to their intranet. That way, the Pi would connect when the phone was in range and the home computers would have internet access without switch networks.

I've got the configuration worked out. In fact, I've already used this setup with my laptop's wireless card (the Atheros QCWB335). Now I'm looking for a usb transceiver that is supported by the Pi and is capable of simultaneous client/AP modes.

The output of iw list can be used to check for support (look for AP and managed together under valid interface combinations).

Can the "official" Pi wireless dongle do this? Can anyone verify another adapter with this capability?

Answer 1

Some years later I have found new possibilities using systemd-networkd to create a WiFi router/repeater. The built-in WiFi device of a Raspberry Pi is capable to create an access point together with a client connection simultaneously as uplink to another WiFi internet router. How to do it you can look at Access point as WiFi router/repeater, optional with bridge.

Of course you can also use a second USB/WiFi dongle if you want to spend additional money. This will simplify the setup a bit. For this setup look at Access point as WiFi router/repeater with additional WiFi-dongle.

Answer 2

Atheros based wifi adapter - TP-LINK TL-WN722N, would definitely solve your purpose of making wifi adapter work in dual mode. The driver should work out of the box on raspian or should be little effort to figure out and install the driver. You would however need other settings to being up vlan interface, etc.

Answer 3

I know this doesn't directly answer the question but I don't have enough rep to comment and I figured this would help anyone trying to do something similar.

Someone put together a great how-to on Github that works with the built-in wifi on a Raspberry Pi 3B using Jessie: https://github.com/peebles/rpi3-wifi-station-ap

For Stretch: https://github.com/peebles/rpi3-wifi-station-ap-stretch

I have personally tested Jessie version and it seems to work. One thing to note however is that the channel used in your hostapd.conf must match the control channel used by the WiFi AP you are trying to connect to. If that is a router it can usually be found somewhere on the router's config page or by running this command from your Raspberry Pi:

sudo iwlist wlan0 scan | grep "your AP ssid" -B 5