I'm looking to develop an application that necessitates multiple devices sending and receiving messages. These messages need not be acknowledged (necessarily), they just need to be sent to all potential recipients in the area. Further complicating the issue, I can't have a centralized solution (i.e. one where a fixed server relays data between clients).
I've looked into a bunch of technologies that should support this to no avail. BLE has a 'broadcast mode' that should do the trick but as of Android 4.4.3 they have yet to support this feature. Wi-Fi direct requires two peers to establish a connection. Same goes for 'classic' Bluetooth.
Is there any technology that is supported by Android that communicates in this way? I'm running into a lot of trouble trying to create a solution that could function without this technology and I cannot.
This is bit of a moot point now that Android L will support BLE in all modes. However, for those who are looking for an alternative they can use immediately, ANT+ (as @Ifor suggested in his comment) is a viable alternative.