User`s guide

38 E6651A User’s Guide
3 Base Station Emulator Mode
Downlink Ping Test
Upon establishing two way communications, control and
broadcast messages are transmitted between the E6651A and
the SS, though no user traffic is present. The E6651A can
test the receiver performance of the SS by transmitting user
data in the downlink direction. To perform the Downlink
Ping Test:
1 Set the Downlink Ping Test Mode: After establishing two
way communications, press in the BSE Mode
Selection Menu to select . is toggle
type.
2 Run the Downlink Ping Test: Press in the
Selection Menu. While DL Ping Test is in progress, the
counts of transmitted packets, received packets and lost
packets in Base Station Information window are being
updated continuously with error rate value.
3 Measure the Signal Quality: In Downlink Test Mode, the
E6651A transmits a downlink signal that is only available
for measurement at the subscriber station. Contact the SS
vendor for a testing tool that may be connected to the SS
for downlink signal performance measurement.
Test Mode
DL Ping Test Test Mode
Run Test
NOTE
The difference between DL UDP Test and DL Ping Test:
The purpose of DL UDP Test and DL Ping Test is to measure downlink performance
of Mobile WiMAX subscriber station.
• In DL UDP Test, E6651A continuously transmits test packets to subscriber
station. And subscriber station sends only acknowledgements to E6651A for
the received packets.
• In DL Ping Test, E6651A continuously transmits test packets to subscriber
station. And subscriber station sends back the received packets.
Therefore, in DL Ping Test, identical load is applied in downlink path and uplink
path. But in DL UDP test, load is applied in downlink direction only.