Controlling Smartphone Data Roaming While Abroad (Part 1)

Data Auto-sync That Causes Heart Attack

Yes you would love to take your smartphone everywhere you go, because of its 1001 functions beyond communication. But, beware if you plan to go abroad. The auto-sync of emails, chats, apps and other background data will cost you enormous amount enough to cause a heart attack. A year ago, on a trip to a neighboring country, my search of  a local restaurant made my phone bill jumped to USD 200 (normally only USD 25/month)...means cost of data roaming exceeded cost of the food I had at that restaurant :(

So, the next time I went abroad, I adjusted some settings on my smartphone. Here's what I did , and proved to be effective. As a note, I still can connect to the internet via wifi (most hotels have wifi , and several countries/cities, e.g Hongkong, provide wifi all over its corner ).

You have 2 options to do with your smartphone : totally disable data roaming, or setting a quota/ limit for data roaming.

This settings is according to Android OS, but actually it's almost the same for i-phone / blackberry, only each OS has its own terminology) :

Do This Before departing abroad :

Option-1 : Totally disable internet/ data roaming

Go to SETTINGS, choose WIRELESS AND NETWORK

select MOBILE NETWORK

Then, disable USE PACKET DATA and DATA ROAMING (by un-ticking the box)

By doing this, your smartphone will not roam for internet/data services. 
If you're still unsure, you can do these additional steps as a second-layer protection :

Go to SETTINGS, select ACCOUNTS AND SYNC

Then, disable AUTO-SYNC and BACKGROUND DATA

Based on my trial, here's the roam/ not-roam performance with combinations of those setting :

In conclusion, the key setting is USE PACKET DATA. As long as it is disabled (OFF), despite settings of other parameters, your phone will not roam for internet/ data service.

If howsoever you chose to let your smartphone connect to internet, then you can set limit/ quota for data roaming according to your budget :)
Check out how  :  
Option-2 : Setting a quota/limit for internet/ data roaming