Android: wifi & bluetooth searching together
Currently I have a question about using Android Wifi, Bluetooth APIs together.
(Please be noted that it's a problem on app development, not for a normal user guide)
I have a trouble when search device' services via Wifi at the same time with searching device via Bluetooth.
For more info:
On wifi search, I use Bonjour protocol (an Apple's implement of Zeroconf which can help locating services that local network devices offer). The Java implement that I use is jmdns. During the search session, I create a MulticastLock in order to receive multicast packages of Bonjour.
On bluetooth search, I just use BluetoothAdapter together with BroadcastReceiver to get bluetooth device info.
Problem happens to the search result, whenever two search sessions above are executed at the same time, mysearch result on Bonjour (Wifi) search has never get enough like it does when only it is executed.
Ex: Bonjour search just gets 1 instead of 2 device' services when search together with Bluetooth. Bluetooth search result is always enough, however.
This is tried many times and I surely confirm that there is nothing related to network' strength problems.
Has anyone met this problem yet?
Even if your situation is about using Wifi together with Bluetooth, any experiences or guests are very helpful to me!
Khoi.
I am doing pretty much the same stuff you are doing. My experience differs in that:
Two possible issues:
Multiple Asynctasks not executing in parallel due to Android faulty implementation . I have had a similar bug after setting my Android API target to the latest SDK (as it is best practice). Now, after API13, Android Asynctask implementation changed and tasks are NO LONGER executed in parallel (so my wifi thread never started for example, if bluetooth thread was running!!!). The fix is to put a couple of lines of code to make the default executor parallel again, or to just use API11 or lower as target version. See this thread for details.
OverTheAir interference between the 2 . Bluetooth discovery is, to my knowledge, the most expensive operation you could do on Bluetooth. So that 2.4GHz multi-purpose chip may be swamped over the air . Internally it has coexistence between WiFi and BT. Remember the WiFi and Bluetooth channels over the 2.4GHz overlap. So what I am saying doing discovery over the same main frequency at the same time might not work that great . You should investigate that...
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