User guide

TD 92422GB
18 February 2010 / Ver. E
System Planning
Ascom IP-DECT System
9
6.2 Building Elements
This section describes how different building elements can affect the coverage.
• The cell size is dependant on the material of which walls, ceilings and floors are made.
• Plain, light or reinforced concrete, wood and plaster absorb and pass radio waves in
different ways.
• Metal walls and large metal cabinet rows reflect all signals, resulting in a greatly
reduced coverage in areas behind these objects.
• X-ray rooms in hospitals protected by lead walls and computer rooms in banking
buildings protected against unwanted interference do not allow radio signals to enter.
• Exhibition halls or production halls may give reflections due to large metal structures.
This causes interference which reduces the capacity and coverage range of the base
station.
6.2.1 Walls
Walls, ceilings and floors have large impact of the coverage range, different types of walls
have different impact on the signal range. For list of the most common types and the
approximate range achieved through these materials, see the table below.
Note: The values in this table are estimated values. Furniture (cupboards etc.), and the
amount of movement in the area to be covered, for example, cranes in a production hall
(see also
6.4 Reflective Environment on page 12) are further factors that affect the
coverage range.
6.2.2 Ceilings and Floors
The difference between ceilings and floors compared to walls lies in the materials used.
Concrete and reinforced concrete are the main materials and it is important to determine
the level of coverage of a base station on the floor above and below. For ‘normal’ concrete
this coverage extends to a radius of approximately 15-20 metres which provides coverage
for the floors below and above. An open stairwell or an atrium can in some cases be used
to provide coverage to two floors at the same time, see
figure 2.
Typ e Examples Range in
metres
Stud wall Plaster 30-60
Concrete 10-30
Reinforced
concrete
Fire wall 0-10
Stone/brick 30-50
Metal A panel on brickwork. 0-10
Wood 30-60
Wired glass Fire protection. 0-10
Surface coated
float glass
Only of importance for coverage
outside if the base station is installed
inside.
30-50
None Open-plan office or outdoors. 150-300