Simulate Slow Internet Connection On A Real Device?

I need to test my application in conditions where even 2G Internet connectivity isn't at its full coverage (i.e. 2 bars instead of 4, 2G). I prefer conducting these tests over WiFi

Solution 1:

In one of your comments you mentioned that you have a DD-WRT router, which is really a tiny Linux box. So you may be able to get a way with the tc command:

tc qdisc add dev $DEV root handle 1: cbq avpkt 1000 bandwidth 10mbit 
tc class add dev $DEV parent 1: classid 1:1 cbq rate 512kbit allot 1500 prio 5 bounded isolated 
tc filteradd dev $DEV parent 1: protocol ip prio 16 u32 match ip dst 195.96.96.97 flowid 1:1

Solution 2:

It kind of depends on what you have on the upstream side. If you're transmitting some kind of test load, write a driver at the upstream end that does, in fact, slow itself down -- although sleep() is a bad choice. What you'll be writing is essentially a fairly hard real-time program if you hope to get anything resembling a real workload.

(When I say "a driver" btw , I don't mean necessarily a device driver, just some kind of driver program.)

But are you really trying to simulate a slow connection, or a degraded and noisy connection that has a low effective data rate?