Simulating network speed and latency for Android devices

Simulating network speed and latency for Android devices

Latency can be because of propagation delays such as satellite or transmission delays due to the physical properties of the medium used for communication.

Having dealt with the concepts of speed and latency, we will now see how to test Android applications on different networks and see how our applications to conditions similar to those of actual use.

Android SDK ships with device emulator. The emulator can be found in the android-sdk /tools folder of your SDK directory. A virtual device can be created that emulates the phone. Android Virtual Device or AVD for short can be launched both from command line and from within Eclipse IDE.

• 
  Every AVD is assigned a separate port, starting from port number 5554
  
• 
  Any AVD runs behind a firewall and is shielded from the network on which the host system runs. The IP address assigned to emulator’s gateway, primary DNS (as well secondary and tertiary), and each instance of AVD, has an IP address of scheme 10.0.2.X
  

Following steps need to be taken:

1. 
   Create AVD
   
2. 
   Run AVD
   
3. 
   Enable Telnet (for Windows 7 or 8)
   
4. 
   Connect to AVD’s console
   
5. 
   Set up redirection
   
6. 
   Change network speed and latency
   

You can run via right clicking project > Run As> Android Application

OR

You can ran via command line

Don’t forget to ‘@’ symbol otherwise the emulator tool would give an error. You can also give network command here at the time of starting the AVD or continue with the rest of the tutorial to issue commands to an already started AVD.

For setting speed at start up:

emulator @deviceName -netspeed gsm

Open ‘Control Panel’

Click on ‘Programs and Features’

Click on ‘Turn Windows features on or off’

Select ‘Telnet Client’ from the list that appears.



Step 4: Connect to AVD’s Console

After starting your AVD, you would see a port number before its name in followed by colon like this:

which will list the virtual devices along with their port numbers

You have the information you need to connect to the AVD.

Just type the following command now

telnet localhost

For example, for the above emulator, we would type


telnet localhost 5554


Step 5: Set up redirection

This is a simple process. You need to:

Use redir command

Decide port number for incoming traffic (your machine)

Decide port number for passing traffic to (AVD)

The subcommand we will use is ‘add’

add
::

where
is the one of ‘tcp’ or ‘udp’

redir add tcp:5000:6000

Step 6: Change network speed and latency

Once you have connected to the console and also set up redirection, you can now set speed and latency levels:

network

You can select one of the available networks

Value	Description	Comments
Gsm	GSM/CSD	(Up: 14.4, down: 14.4)
hscsd	HSCSD	(Up: 14.4, down: 43.2)
Gprs	GPRS	(Up: 40.0, down: 80.0)
Edge	EDGE/EGPRS	(Up: 118.4, down: 236.8)
Umts	UMTS/3G	(Up: 128.0, down: 1920.0)
hsdpa	HSDPA	(Up: 348.0, down: 14400.0)
Full	no limit	(Up: 0.0, down: 0.0)
	Set an exact rate used for both upload and download.
:	Set exact rates for upload and download separately.

You can also specify the speed yourself:

network 14.4 80

network delay

Where type can be any of the following:

Value	Description	Comments
gprs	GPRS	(min 150, max 550)
edge	EDGE/EGPRS	(min 80, max 400)
umts	UMTS/3G	(min 35, max 200)
none	No latency	(min 0, max 0)
	Emulate an exact latency (milliseconds).
:	Emulate an specified latency range (min, max milliseconds).

Once you have set the speed and latency, you are would see a remarkable difference in the emulator’s usage!

Happy testing everyone.

References:

http://developer.android.com/tools/devices/emulator.html