How to enable engineering/field test mode in blackberry

Blackberry phone has best engineering mode. You can enable it by using below steps:

Blackberry has a very nice and interesting field test/Engineering mode.
While reading a blog I show that pressing ALT+CAP+H would display usefull  information about your mobile.
But you can enable the engineering mode from this screen using steps metioned in the blog:
http://www.zibri.org/2009/08/hidden-things-are-usually-best.html
Please make sure to follow steps very clearly. Read it twice! 

UMTS Mobile Originated call flow sequence diagram (Mobile to Landline)

UMTS Voice call flow diagram for mobile to mobile call

This call flow is captured at RNC.

3G Handover Events 2a, 2b, 2c.. explained

·         Event 2a: Change of Best Frequency

·         Event 2b: The estimated quality of the currently used frequency is below a certain threshold and the estimated quality of a non-used frequency is above a certain threshold

·         Event 2c: The estimated quality of a non-used frequency is above a certain threshold

·         Event 2d: The estimated quality of the currently used frequency is below a certain threshold

·         Event 2e: The estimated quality of a non-used frequency is below a certain threshold

·         Event 2f: The estimated quality of the currently used frequency is above a certain threshold