User's Manual

Parameter
Meaning
Received Signal Strength Indication (RSSI)
A measure of the signal strength in a wireless
environment. The higher the value, the
stronger the signal.
Frame Error Rate (FER)
A measure of the signal connection quality.
The lower the FER, the better the signal
connection.
Link Quality (LQ)
A combined quality metric ranging from 1
(poor) to 5 (high).
Table 3-1 Key to site survey terms
4) Walk around the antenna with the beltpack, monitoring the beltpack signal strength
and goodness rating at various distances.
The signal strength is shown in the Received Signal Strength Indication (RSSI) field.
• The signal strength number will fluctuate, ranging between 0 - 59 as you walk
through the coverage area, and may even fluctuate as you stand still. As a rule-of-
thumb the best system performance will be obtained when the signal strength
remains at 30 or above. If the signal strength falls below 30 the beltpack may start
losing audio. This is the limit of the coverage zone.
• A high Received Signal strength indication and a high Error rate may indicate that
there is another RF system causing interference.
A beltpack can transmit to an antenna at a range of approximately 500m in good conditions.
5) Draw a map of the coverage zone for the antenna. The coverage zone is the area
where the signal strength, as a rule-of-thumb, is 30 or above and the Line Quality is
3-5.
6) Repeat this process for as many antennas as necessary to cover the required area.
Overlap coverage zones so that there is no area where the signal strength is below
30, and no area where the error rate is above a few percent.
7) The antenna placement will need to be adjusted to get the best coverage.
Figure 3-5 Mapping overlapping coverage zones
In some environments you might observe that despite having a high signal strength, the
beltpack consistently reports a high error rate.
Zone A
1 user
Zone C
4 users
Zone B
5 users
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FreeSpeak II User Guide