User guide

TD 92422GB
18 February 2010 / Ver. E
System Planning
Ascom IP-DECT System
25
9.4 Base Station Planning Tips
All information needed to do a solid base station planning are given in sections 4 to 9.
Below is a list of some other important issues to consider:
• Always involve the client in the site survey. Ensure that the client shares the
responsibility for the decision on the siting of base stations. Also always involve the
client in problems which you encounter (a difficult area to cover), and ensure that the
client is not faced with surprises afterwards.
• Pay particular attention to the ‘non-standard’ areas such as toilet rooms, stairwells,
lifts, maintenance shafts etc.
• Always mount a base station at least 30 cm away from a metal wall, to avoid a
substantial impedance change for the antennas.
• Always try to place the base station in a way that it can "see" as much as possible of
the area to be covered.
• Place the base station strategically: for example, do not place the base station on a
large concrete pillar in the middle of a hall since this will result in bad coverage behind
the pillar.
• To achieve outdoor coverage, mount a base station on a wall containing a window.
Place the base station with its antennas in front of the window or in a way that the
base station can see as much as possible of the outdoor area.
• Base stations should not be placed near the outer walls of the building as this reduces
the effective covered area, except of course when outdoors coverage is desired.
• Always keep the necessary traffic capacity in mind during the site survey. How many
people there are in a particular department, how often people call on average and how
long people call on average. A standard rule of thumb for this ratio is one base station
for 27 people. If you are dealing with, for example, a purchase department, the ratio
will quickly change. Talk this over with the client.
• If you need to place two base stations close together separate them with at least 30
cm.
• Base stations should be placed as far away from other DECT systems (home base
stations, DECT headsets, etc) as possible. Placing them close (line of site) to each other
may cause interferance as the systems are not synchronized. Se appendix A.
• Ensure that during the installation of a base station, the base station is given an extra
length (5-10 metres) of cable because it is possible that it will have to be moved for
one reason or another.