Handbook

ClearFill Star CDMA
1100187 Rev. 1.0
Page 29 of 152
3.2.4 Number of Users
One CDMA channel can handle up to 56 users at the same time. A ClearFill®Star BSI
supports the capacity of 1 CDMA carrier. If more capacity is required, additional CDMA
carriers can be designed to overcome capacity limitations.
Fairgrounds, theatres, stadium areas, meeting rooms and campuses
are areas that might require capacity extension.
Capacity planning has to be discussed with the network operator,
responsible in general for the Base Transceiver Station.
1
st
step: Estimate number of subscribers
2
nd
step: Determine Erlangs usage
 In-building clients > 25 mE/sub average
3
rd
step: Decide quality of service (QoS)
 2% blocking high
 Recommended 0.2 % blocking
Erlang B table should be used to verify the required number of channels.
The result may necessitate more than 1 RF source.
Figure 13 Erlang B formula
10
0
10
1
10
2
10
-3
10
-2
10
-1
Traffic Intensity in Erlang (A)
Probability of Blocking (P
b
[blocking])
#Trunked channel, C=6
#Trunked channel, C=14
#Trunked channel, C=22
#Trunked channel, C=30
#Trunked channel, C=38
#Trunked channel, C=46
(0.002; 1.32)
(0.002; 5.92)
(0.002; 11.52)
(0.002; 17.60)
(0.002; 23.97)
(0.002; 30.54)
Figure 14 Traffic Intensity
Erlan
g
B formula




C
k
k
C
b
k
A
CA
blockingP
0
!
!/