User's Manual

Table Of Contents
PMP 450 Operations Guide
Using the Throughput Monitoring Tool (AP)
pmp-0049 (September 2012)
5-23
Using the BER Results Tool (SM)
Radio BER data represents bit errors at the RF link level. Due to CRC checks on fragments and
packets and ARQ (Automatic Repeat reQuest), the BER of customer data is essentially zero. Radio
BER gives one indication of link quality. Other important indications to consider include the received
power level, signal to noise ratio, and link tests.
BER is only instrumented on the downlink and is displayed on the BER Results tab of the Tools page
in any SM. Each time the tab is clicked, the current results are read, and counters are reset to zero.
The BER Results tab can be helpful in troubleshooting poor link performance.
The link is acceptable if the value of this field is less than 10
4
. If the BER is greater than 10
4
, re-
evaluate the installation of both modules in the link.
The BER test signal is broadcast by the AP (and compared to the expected test signal by the SM) only
when capacity in the sector allows it. This signal is the lowest priority for AP transmissions.
Figure 48 BER Results tab of the SM
Using the Throughput Monitoring Tool (AP)
The PMP 450 AP has a tab Throughput under the Statistics category which shows historical
information about sector throughput and packet discards. This information can be useful to identify
an overloaded sector or heavy bandwidth users. This page also shows the user throughput in terms of
data rate (kbps) and packet rate (packets per second, or PPS), as well as the average packet size during
the sample period. Operators may set the AP to send an SNMP trap when it detects an RF overload
condition based on a configurable threshold.