Gigaset N870 IP Pro Site Planning And Measurement Manual page 21

Grade Calls at 3 min. per hour
of service
10
0% 0.5 E
2% 0.49 E
4% 0.48 E
Grade Calls at 15 min. per hour
of service
10
0% 2.5 E
2% 2.45 E
4% 2.4 E
Alternative calculation for small systems
For smaller systems, an approximate evaluation of the traffic volume can be sufficient.
Example:
Calculation details:
•
It is a small-scale system. One Gigaset N870 IP PRO contains the integrator, DECT manager
and a base station.
•
Narrowband connections with codec G.711 or G.729 are approved.
•
The base station that is on a system together with the DECT manager and integrator makes
available 5 connection channels. The other base stations each have 8 connection channels.
•
The traffic volume is evaluated for every area as "low", "medium" or "high". The evaluation
specifies the number of handsets (as a %) that require a connection simultaneously:
Evaluation %
Low Approx.
25%
Medium Approx.
50%
High Approx.
80%
Hotspots
A hotspot is an area in which more calls than average are conducted simultaneously, e.g.,
open-plan offices or other areas where there are a lot of handsets in a small space.
You can cover such areas with several base stations since the DECT bandwidths in the coverage
areas of neighbouring base stations add up. The DECT standard provides 120 radio channels that
can be shared by several base stations. In practice, however, approximately only one quarter
of these radio channels can be used without special measures, since the neighbouring channels
interfere with one another. This results in a practical value of a maximum of 30 simultaneous
50 100
2.5 E 5 E
2.45 E 4.9 E
2.4 E 4.8 E
50 100
12.5 E 25 E
12.25 E 24.5 E
12 E 24 E
Max. number of handsets that can
be handled by a base station
For 8 connection channels
32
16
10
Projecting the DECT network
The table contains some
sample values for the calcu-
500
lation of the traffic volume
25 E
depending on the grade
of service, call duration and
24.5 E
number of calls per hour.
24 E
Using the data you have
determined about the
telephony behaviour,
500
you can realistically estimate
125 E
your requirements.
122.5 E
120 E
For 5 connection channels
20
10
6
21