Page 8 - Site Surveys
Base Station Coverage: In Theory
Base Station Coverage: In Theory
Given ideal open field conditions, the range between a handset and base station can
be up to 600 metres. Within a building, with signal strength being absorbed and
reflected signals giving increased error rates, the effective range is more realistically
between 50 metres and 150 metres.
A single base station's area of coverage is
Π
xR
2
R
With multiple base stations working together, areas of coverage intersect. Each
base station provides main coverage for an area 2xR
2
(the
square areas below).
Naturally the base station signal still goes outside that area but normally calls are
handed over to the next base station at that stage
R
R
R
In the worst case, call handover from one base station to another can take up to 10
seconds to complete. Thus for handset users moving at normal walking pace, base
station coverage areas need to overlap by at least 10 metres to ensure successful
call hand-over.
Maximum
overlaps
supported
All the above assumes a lot of things:
– That each base station has sufficient free channels. If there is no free channel
for a call handover, the handset will remain with its current base station until out
of range and the call is lost
– That the building structure is even such that the base station has the same
range in all directions
– That base stations only operate in 2-dimensions. In reality the signal forms a
sphere rather than a circle
Page 8
Installation Manual
38DHB0002UKCA – Issue 8 (26/03/2002)
INDeX CSLC