Can I waked a sleeping Android without an app installed? I am aware of Wake on LAN, but that has been ruled out as it requires a device to have an app installed (doesn't it?).

A friend wants to develop an access point and wants to be able to wake any sleeping devices in range.

I don't think that that is at all possible, but would be happy to be proved wrong.

In fact, I don't see how he would even know that a device was in the area unless it was using his access point or was open for BlueTooth pairing.

Can what he wants be done? Note that these are random, passing 'phones, so we cannot expect them to have any app installed.
No. If you could do this it would be a huge security flaw. You could use it to run down the batteries of all phones in range of your device by continually waking them up.