In ideal open field conditions, the range between a phone and a standard base station can be up to 600 metres (2000 feet). However, in real conditions with obstacles absorbing signal strength and reflected signals giving increased error rates, the range is more realistically between 30 metres (100 feet) indoors and 300 metres (1000 feet) outdoors.
In practice, no rules or guarantees can be specified for base station coverage. Coverage is affected by too many factors that are unique to each site. The following is a guide to some of the factors that can affect coverage and which you should consider and look for during any site survey.
Type
Potential Factors
Obvious causes of signal problems
Metal surfaces.
Concrete thickness greater than 1 metre (3 feet).
Beware of
Windows with Reflective Film or Specialized Glass.
These produce increased signal reflection and reduced signal pass-through.
Wire Meshes and Grills with Apertures of Less than 4cm (1.5 inches).
These block signals as effectively as continuous metal sheet.
Fire Doors
These block the signals. In multi-occupancy building such as hotels, the high number of fire-doors may be a problem.
Stair Wells
In modern office buildings, stair wells frequently combine concrete building supports, fire doors and the intervening floor material, making them a special problem.
Screened Rooms
Typically found in offices involved with TV, video and radio production, but also possible in computer centers.
Empty Sites
Do not perform a survey on a site that is not yet occupied. The survey results will differ from those of the same site once occupied by the customer business. Similarly the survey should be performed during normal business hours in order to assess the areas of usage and the effect of equipment being operated and moved.
Be aware of
Signal Direction
The signal from a base station does not propagate evenly in all directions. The signal typically propagates strongest in the horizontal plane. However the ability for a base station to serve callers located on floors above or below it should not be ignored. This may allow coverage to be extended to areas not frequently used and so not meriting a dedicated local base station.
Other Radio Signals
The ability to receive normal broadcast radio signals in an area is not an indication that DECT signaling will be received and vice versa.
Rack Chargers
A rack charger (6 phones) immediately creates an area where a single base station (8 calls) would be near maximum capacity. Look to provide overlapping base station support to areas where rack chargers will be located.
