I am experimenting with connecting my Galaxy Ace to my laptop via WiFi. Both devices are connected to a router via WiFi, and both sides use Java.

After a TCP connection gave me very high pings from time to time, I decided to base the connection on UDP, to be able to control when the packets are actually sent.

However, it seems like Android still buffers UDP packets and does not send them immediately. This, or it shuts down WiFi completely, if there is no outgoing data transmitted for some fraction of a second.

First, I pinged the phone at irregular intervals of about once a second, repeatedly sending ping requests, as long as no answer was received (covering packet loss in UDP):

    computer -> phone -> computer
    Pinging 192.168.1.40: 148.05968ms
    Pinging 192.168.1.40: 524.41156ms
    Pinging 192.168.1.40: 705.8688ms
    Pinging 192.168.1.40: 3.705367ms
    Pinging 192.168.1.40: 3.872159ms
    Pinging 192.168.1.40: 549.4541ms
    Pinging 192.168.1.40: 479.29843ms
    Pinging 192.168.1.40: 3.89936ms
    Pinging 192.168.1.40: 428.85876ms
    Pinging 192.168.1.40: 739.28125ms

I worked around this problem by sending packets from phone to computer with just 1 byte of data every 100ms, changing nothing on the routine other than that:

    computer -> phone -> computer
    Pinging 192.168.1.40: 4.147753ms
    Pinging 192.168.1.40: 3.738213ms
    Pinging 192.168.1.40: 14.133768ms
    Pinging 192.168.1.40: 4.470561ms
    Pinging 192.168.1.40: 3.628386ms
    Pinging 192.168.1.40: 3.898334ms
    Pinging 192.168.1.40: 3.512401ms
    Pinging 192.168.1.40: 7.907006ms
    Pinging 192.168.1.40: 5.234216ms
    Pinging 192.168.1.40: 5.639137ms

It is crucial for my application to have low latency, so I would keep sending empty packets like this (at least as long as there is no real data transmitted). I am wondering, if I can force android to respond as fast as possible, with

java android udp ping latency
Edit
Report