You can't achieve this by using Stepping TG. JMeter lets you simulate network bandwidth very easily but it is not possible in Thread level.
JMeter does give you the option to throttle outgoing bandwidth in order to simulate different network speeds. The bandwidth can be controlled through these two properties:
httpclient.socket.http.cps=0
httpclient.socket.https.cps=0
These are for the HTTP and HTTPS protocols respectively.
Configuration prerequisite:
You will find these properties in <jmeter home>/bin/jmeter.properties
location.
The acronym “cps”
stands for "characters per second".
cps values are calculated with this formula :
cps = (target bandwidth in kbps * 1024) / 8.
For some popular bandwidth presets and more detail you will find these two blogs Controlling Bandwidth in JMeter and How to Simulate Different Network Speeds in Your JMeter Load Test really helpful.
If you run your test in the distributed mode you can set a different bandwidth for each remote engine by specifying your desired “cps” value in the user.properties
file.