Traffic Capacity Of The System - Avaya DECT R4 Installation And Administration Manual

Traffic capacity of the system

The traffic capacity of the IP-DECT system is mainly determined by the number of base stations
and in exceptional cases also by the LAN bandwidth. A single base station has a capacity of
eight simultaneous calls.
The traffic capacity of the IP-DECT system is determined by:
Grade Of Service (GOS) accepted by the customer.
●
Number of speech circuits available - 8 circuits for each IPBS.
●
GOS is the probability that a call cannot be made because of congestion in the system. The
customer must indicate the acceptable grade of service. A grade of service of 1%, or 0.01,
means an average of 1 lost call in every 100 calls.
The two parameters, GOS and the number of speech circuits, and the total amount of traffic that
is required are related to each other. The total traffic generated by all cordless phone users is
called the erlang value. The following table shows an example of these relations. You can use
this table to calculate the number of base stations required based on GOS and the erlang value.
A base station provides for 8 speech circuits.
Number of
base
stations
1
2
3
4
5
6
7
8
The table below shows what erlang values practically mean in call-minutes for a cordless
phone.
Avaya DECT R4 - Installation and Maintenance Guide
Figure 4. .
Speech Grade Of Service (GOS)
circuits
2%
8 3.6
16 9.8
24 16.6
32 23.8
40 31.0
48 38.4
56 45.9
64 53.4
Traffic capacity of the system
1% 0.5%
3.2 2.7
8.9 8.1
15.3 14.2
22.1 20.6
29.0 27.3
36.1 34.2
43.3 41.2
50.6 48.3
0.1%
2.1
6.7
12.2
18.2
24.5
30.9
37.5
44.2
55
02/2016