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My experience and hints with LG-Nortel DECT systems.

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doktor

IS-IT--Management
Dec 3, 2003
3,841
DK
Hello all.

During the years I have installed several wireless telephony systems with integrated DECT like
LG-Nortel (ipLDk-24/50/100 and GDK-FP-II/162/20W).
Correct deployment (i.e. installation and location of DECT base stations) is a must! –
This experience I have got through the years.
Problems and trouble with handover, radio coverage etc., I have guided and helped my colleagues to solve, through the years also. We have solved many strange cases!

Begin your success by following the steps...

1.
Correct deployment and check of the radio coverage area.
Your first visit to the costumer is to check the radio coverage area and find out where to install the bases.

- Use the LG DECT measuring kit with the test base and the GDC-handset.
- Remember to make your documentation - including what has been promised to the costumer.
- Use the correct drawings of the buildings to mark where the bases should be placed.
- Take photos of the rooms. Sometimes a storage room is empty when you carry out these tests.
- At your next visit to the costumer, the whole storage room is filled with metal shelf with metal
objects!
- Make the costumer sign the deployment report (with the number of base stations agreed upon).


2.
The installation of the LG telephone system and the DECT part.

Make sure to have the documentation from the deployment test with you.

*Always install the base station according to the deployment test report.
*Always install the base station vertically on the wall, never horizontal on the ceiling.
*Always install the base station 30 to 50 cm below the ceiling, and avoid placing it over hanging
ceilings.
*Always install the base station where it can not be hit by persons or vehicles. (Fixed location).
*Always install the base station where the radio signal can not be blocked by parked cars/trucks.
*Never install the base station on or near ventilation pipes or drain pipes.
*Never install the base station on columns or pillar of metal or concrete.
*Never install the base station on metal surfaces - like cable trays.
*Some types of windows contain metal (lead). So be careful if you install the base stations near
windows.
*If you install base stations outside buildings, make sure that they are installed in a waterproof box!

*Install your base stations with 10-15 % overlap, so the DECT users do not experience drop-outs, when they are leaving one DECT zone to go to another DECT zone.

Some times it is better to install the base station hanging down from the ceiling using a special holder.
This holde can be made of a wooden stick and a wooden plate.

With e.g. LG-Nortel ipLDK-100, use the newest software:

MPBN software: 3.7Bd or never.
WTIBE software: 1.0Ec or never.
GDC 400 Base software: 1.0Ca or never.
GDC 400 Handset software: 1.0Am or never.

Make sure that these items are upgraded (It is best to do this from home - not at the costumer site).
Use your GDC-TRC box to upgrade the WITBE and GDC-400B bases.


After installing the DECT system with WTIBE and GDC-400B, it is time to make a cable test measurement.
Use only CAT-5 cabling. (we use only one CAT-5 cable per base station).
Add a ferrite core in both ends of the cable.



3.
After the installation - Service after installation.

Now the system is up and running and we think that all aspects have been covered!
But still the costumer has a different opinion.

I have - below here - written 3 costumer cases - for your information.

A:
We had one customer, where most users were happy with the installation.
Some users complained about call drops.
(i.e. handover faults), After a more careful examination we found out that the persons were using roller scates (shoes with wheels on them) to solve their job.
They were internal mail-men in the company in question.
Using their roller scates they were moving too fast - so the handover could not
take place because of the base stations were too far away from each other.
The overlap between two bases was too small. So we added one base to enlarge the overlap
between the bases.
Problem solved!

B:
We have had some problems when installing DECT base stations on metallic walls, because of the
reflexions of the radio signals.
If you install a base station like the ones we use, where the radio emission has the shape
of a sphere (ball), a lot of reflected radio signals will be emitted from the metallic surface.
Reflected radio signals are bad to use for e.g. handover, so to avoid reflected signals, a wooden
plate should be installed between the radio base station and the metallic surface.
The wooden plate acts like an absorber for the reflected signals. The plate should be at least 5-10 cm. wider and higher than the base, and the thickness should be 3 cm.
Only use wooden plates made of natural tree, not chip boards or similar.

C:
We have a costumer case with a problem like this.
In an building, where some companies shared the space we used quite some time to solve an issue with two DECT systems located very near each other. The DECT was of the integrated type installed in PBX'es from different manufacturers. The 10 DECT frequencies were "stolen" by the one system, some users in the other system had many problems with dropped calls and handover that did not work.
The Solution was to paint the wall between the two companies with paint that contains lead. In fact metal plates vere put up on that wall later to stop the radio signals from the other system.
Another issue we had at a customer site where their old DECT system and base stations were hidden in the building and everybody thought that the old system was switched off.
But it was not!
It took some time to find out.
After the old system was switched off - no problems!


Last costumer issue...
We swapped a GDC Flat Pack telephone system with an ipLDK-100, because the costumer needed more
base stations. They were enlarging their company, and had brought a building next door.

So instead of using the GDC-330B bases, we installed GDC-400B.

Their "old" building had 8 pcs. of GDC-330B before. Now 8 x GDC-400B were installed in the "old" and 4 pcs. of GDC-400B in the "new" building.

It was now important to know that the number of channels is "1" lower.
The number of channels in GDC-330B is 5.The number of channels in GDC-400B is 4.

We had now 20% less channels in the "old" building with GDC-400B compared to GDC-330B!
So after adding two pcs. of GDC-400B in the "old" building, we came up on the 40 DECT channels (10x4) to cover the area.
Before the two extra bases were installed we saw many "no channel" warnings in the displays of
the GDC DECT handsets.

Let me know your opinion - and questions.
Best regards
///doktor

 
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