With so many varieties of communications technologies as to date, many of us including engineers are still confused how to understand its basic operation and why do some operators prefer to implement one technology over the other. Well, I had also experienced the same when I first jumped into this industry and to make things worse, we tend to go so details at one technology and when its time to explain their general concept.....we just couldn't do it. You know why? Because we ourselves don't understand the overall concept of telecommunications. Well, my next postings will be a series of articles about this industry that I want to share with you guys. Most of them are from other sites that I handpicked, just to make sure you will only read the right material for you to grab the basic idea.

Last week, I solved one radio link problem that connects between two places in eastern part of my country. One node is in the mainland while the far end node is in the island.
The problem was significant performance error (BBE and ES errors) that were received by "far-end" node. Actually this problem was reported by our customer 2 weeks earlier and with assistance from our counterpart in Europe, we managed to find the solution within a week.
It happened that the radio unit of the far end was faulty and here is the step-by-step procedures that I had taken to detect the problem:

1) Analyzed list of history alarms for both nodes. As rule of thumb, this is important to detect any problem that is related with telecomm. equipment as it will show you when the problem starts and what cause it to start. In this case we found out that
2) Analyzed G.826 performance report. Just to confirm what you get from test equipment, or in case if you operate from NMC (network management centre)
3) Important step-- do the looping test. This is the simplest, yet very powerful method to detect any fault in transmission area. But you have to understand what you will do from the start.
Normally, for a radio system you will have,

DDF---interface unit---modem unit----radio unit----antenna---

so first you have to start from DDF level, followed by interface unit and so on.. You will know where is your problem area until the test gear/performance start giving error.