Switch Planning for GSM

Hi Sudhir,

if you can send your answer for AT’s question to the forum, we can also learn sth. Thanks.

To Dan:
There are various anntenna models available from Kathrein or Algon that have an adjustable electrical tilt. I haven’t seen one that you have to change ports to effect the change. Most come with the a adjustment knob/dial on the bottom or back of antenna.

The Kathrein 742 047 is an example of a dual band, 4 arrays ( 2 +45 degree and 2 -45 degree ) where the 900 array can have it’s elec tilt adjusted.

As for horizontal or vertical polarisation, it’s not correct to say that hp is more attenuated than vp.

Consider that in space there is no such think as vertical or horizontal and no matter how you rotate the antenna it will propagate the same.

However because of different effect that V and H polarised waves encounter when being reflected off the ground and other objects, V waves tend to keep their polarisation, while H waves then to get rotated and suffer higher relection losses.

To Rachid and Mostafa:

E///’s definition for Sudden Loss is compatible to Mostafa’s definition of “other”.

However please not that the “due to” is not exactly correct. The statistics only tell you that at the time of the drop there was a Bad Quality, Low Signal Strength, or exessive TA urgency state (or none in the case of other or sudden loss).

Depending on the thresholds you set for what is low SS or bad Qual or excessive TA, the validity of these stats can be questioned.

has anyone come across the tool ASSET from AIRCOM if so, have they come across the problem with the discrepeny table report discepencies across a 900/1800 dual band network. From what I know these tables should be sperate

Bruce

In GSM, there are two types of values presented for RXQUAL, namely RXQUAL FULL and RXQUAL SUB, RXLEV, the parameter representing the signal strength also has similar FULL and SUB values.

The FULL values are based upon all frames on the SACCH multiframe, whether they have been transmitted from the base station or not. This means that if DTX DL has been used the FULL values will be invalid for that period since they include bit error measurements at periods where nothing has been sent resulting in very high BER.

In total, 100 bursts (i.e. 25 blocks) will be used for the FULL values.

The SUB values are based on the mandatory frames on the SACCH multiframe i.e. frames that always must be transmitted. There are two frames fulfilling that criteria and that is SCACCH block and the block holding the SID frame. If DTX DL is not in use, the SID frame will contain an ordinary speech frame and then this is included instead. In total 12 bursts (2 blocks) will be used for the SUB values (4 bursts SACCH and 8 halfbursts SID (or speech) information).

Can any one tell me if a high rate of VSWR on antenna system may cause drop call?

Thanks.

To satish,

I think taht TRXs are designed for a special encryption algorithm, so its hardware definiton.

hi Imran
whats ur email address. send it to me on ashish_tandon@hotmail.com… i wud like to discuss with u few issues on siemens NSS planning. i have also been discussing it with amin sudhir on this forum and wud like to discuss some issues amongst us
tx
at

I am not working in D900 but worked for some time…one month but never touched..

But I like to have some basic knowledge through you guys .

mail me your mail ids….

sunil_almnthat@yahoo.com