Innovating the Future of Global Communications
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6
Performing a Site Survey
A site survey is performed to determine the placement
of access points to ensure RF coverage of the desired
area. A beltpack, communicating with an access point at
a test location, is set to the site survey screen where
RSSI
(Received Signal Strength Indication) and
QF
(Quality Factor)
are both used to find the RF coverage area.
Prerequisites
• Have a beltpack that has been successfully subscribed to
an access point.
• Have a site map or blueprint of the building that can be
marked up.
• Power can be supplied to the access point at the possible
test locations either by using power extension cables or
battery power.
• For battery power 12VDC @ 0.600 Amps must
be available to the access point. A charged
12VDC battery rated for at least 2.4 Amp-hours is
recommended for a typical site survey length of time.
• The input connector required for an access point
is a 13.8mm long, female barrel, 2.5mm x 5.5mm
connector.
NOTE
: The unit is marked 1.5 Amps. This is an upper limit set
to handle peak loads when fully loaded. When doing
site surveys, an access point is not heavily loaded.
To
perform a site survey
, do the following:
1. Place the
access point
in the location to be tested for
coverage.
2. Power up the
access point
.
When the power light turns solid green, the access point is
ready.
3. Power up the
beltpack
.
The splash screen momentarily displays and then the
home screen appears.
NOTE
:
When the beltpack finishes booting, the
home screen indicates a wireless connection.
If the wireless connection does not display, verify
settings in the “Setup for a Site Survey” section.
4. Press the
Menu button
.
The beltpack main menu appears
.
5. Using the up and down arrow buttons, navigate to the
System Setup icon
.
6. Press the
SELECT button
.
The beltpack system setup menu appears
.
7. Using the up and
down arrow buttons, navigate to
the
Site Survey icon
.
8. Press the
SELECT button
.
The site survey screen appears.
CARRIER -
Current RF carrier of the access point (this
may change from time to time)
SLOT -
Current time slot on the RF carrier the access
point to beltpack packets are on (this may
change from time to time)
AP ID -
Access Point Identification
RSSI -
Radio Signal Strength Indication
QF -
Quality Factor. This is representative of the
number of packets received out of packets
sent
Meaning of RSSI
RSSI
Color Description
0-47
Red
Weak - poor to no reception in area
48-70
Yellow Marginal - some dropouts of audio in area
71-216 Green Strong - good RF coverage
Meaning of QF
QF
Color Description
0-4
Red
Weak - too many dropouts in the area
5-6
Yellow Marginal - some dropouts of audio in area
7-10
Green Strong - good RF coverage
9. Mark the
access point’s location on the building layout
diagram
.
10.
Walk around
with the beltpack throughout the area(s) of
interest while looking at the site survey screen.
NOTE
: If performing a survey of an installed system,
monitor the AP ID displayed on the site survey screen
to view where coverage area boundaries exist.
11. Record the
RSSI
and
QF number
on the building layout
diagram at several locations throughout the area of
interest.
GOOD COVERAGE AREA DEFINITION:
RSSI = 71 – 216, Site survey bar in the green.
QF = 7 -10, Site survey bar in the green.
If the two indications are different, always use
the worst case of the RSSI and QF indications
for defining a good coverage area. Example: QF
= 10 and RSSI = 71, use the RSSI level as the
cutoff for the good coverage area.
12. When you have collected enough data points, draw a
line on the building layout
, using the coverage limits as
shown in the good coverage area definition information
