Help! Neighbor Cell Detection Mechanism in GSM

[cdmahn]

Hi,

I've used Actix Spotlight to drilldown the Call Setup Failure and the it appereared as the attached image.

There are some points that I cannot understand, especially which related to the neighbor cell detection mechanism that the mobile use in the measurement report. I also made notes from 1 to 4 in the image.

Please help me to explain as follow:

1. See Note 1 and 3. Why did MS detect them to be 2 sectors with the same BCCH, BSIC (very bad case in design)? Why can't it detect these 2 signals to be 2 versions of the same sector near its position due to fading/propagation? You see in Note 4 that the distance from MS to sector 3 of the near site (Pham-Hung) is much lower than to the Thinh-Hao site.

2. See Note 2. What is incorrect, my local cell database (made by myself) or the neighbor list (from system database)?

Thank you in advanced

[cdmahn]

I express my question in another way:

You see in GSM Serving + Neighbor chart of TEMS Investigation these following information:

==============================
Site Sector Chan BSIC RxLev Full RxLev Sub RxQual

site(1) sec(1) chan(1) bsic(1) levf(1) levsub(1) qual(1)
site(2) sec(2) chan(2) bsic(2) levf(2) levsub(2) qual(2)
...................................

===============================

Among above parameters, TEMS may get Chan, BSIC, RxLev, RxQual from the RR Measurement Reports.

However, I don't know how TEMS get Site and Sector information?

I think there may be some way that it can detect these information:

a. From the Cellfile that we made ourselves.
In that case, the Site and Sector information are based on the BCCH and BSIC, but it is a problems if there are at least 2 pair of same values.

b. From a message that BTS send to MS about Neighbor List information. Then, please let me know what message contains such information.

Could someone please give me the explaination about the real mechanism of the mobile networks.

TIA,