Aastra X Series, Installation And Implementation Manual

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AMT/PTD/TR/0020/2/7/EN 10/2008 Page 3-68
3.3 Method of determining the number of base stations
according to predicted traffic
This method allows you to determine the number of base stations required to provide service in a
coverage area.
Proceed as follows:
1
Identify the traffic areas and divide them into two categories:
• Homogeneous traffic areas
A homogeneous traffic area consists of radio areas located within the same geographic
sector that generate the same level of traffic (building or floor where users generate a
generally constant level of traffic, without leaving this sector).
• Special traffic areas
A special traffic area consists of radio areas located within a given sector, where the traffic
level varies from one radio area to the next (meeting room, cafeteria).
2
For each homogeneous and special radio area, the following parameters must be obtained
from the customer:
• N: total number of mobile DECT users.
• Z: number of radio areas in the traffic area.
• m : the mobility of users within a given traffic area.
Mobility is defined for each user based on information provided by the customer during the
interview. Mobility, "m", may have the following values:
• low: mobiles tend to stay within their reference areas.
• medium: intermediate.
• high: mobiles often stay outside their reference areas.
• e: traffic in Erlangs per mobile.
• low = 0.04 medium = 0.12 high = 0.2
If the customer does not know the exact user traffic in minutes per hour, the table below,
giving typical traffic levels for various business functions, may be used as a guide to
estimate the average traffic.
Table2: Determining the average traffic of the various types of activity
The traffic level given is busy hour traffic.
Traffic per mobile Business function
Low ( < 5 min./h) hotel
school
Average (from 5 to 10 min./h) work yard
retail store
plant
advertising agency
High (from 10 to 20 min./h) hospital centre; locations close to operating
theatres
law firm
real estate agency
stock broker
garage, workshop reception (20/25 min./h)