User guide

Installing a BH Timing Slave Installing Components
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pmp-0229 (Mar 2013)
13. Access the General tab of the Configuration page of this BHM.
14. If a CMMmicro or CMM4 is connected, set the Sync Input parameter to the Sync
to Received Signal (Power Port) selection.
If a CMM2 is connected, set the Sync Input parameter to the Sync to Received Signal (Timing
Port) selection.
Installing a PTP 200 Series BHM
To install a PTP 200 Series (OFDM) BHM, use the procedure provided under Installing a PMP 400 Series
AP on Page 386, with the following additional treatment for a setting that is unique to PTP 200 Series
wireless Ethernet bridges.
OFDM technology uses a cyclic prefix, where a portion of the end of a symbol (slot) is repeated at the
beginning of the symbol (slot) to allow multipathing to settle before receiving the desired data. A 1/4 cyclic
prefix means that for every 4 bits of throughput data transmitted, an additional bit is used, A 1/8 cyclic
prefix means that for every 8 bits of throughput data transmitted, an additional bit is used.
PTP 200 Series modules (OFDM BHs) are settable for either 1/8 or 1/4 cyclic prefix. The use of 1/8 cyclic
prefix provides about 11% higher maximum throughput and is recommended for most cases.
The Cyclic Prefix is set on the Configuration => Radio page of the BHM. The default on a new unit or
after the unit has been reset to factory defaults is 1/4 Cyclic Prefix. In most deployments, 1/8 Cyclic Prefix
will provide a high quality, higher throughput link. In cases with severe multipathing or obstructions, 1/4
Cyclic Prefix may yield better overall results.
Procedure 27: Setting the Cyclic Prefix in a PTP 200 Series wireless Ethernet bridge
1. Before deployment, set the Cyclic Prefix on the Configuration => Radio page of both the
BHM and the BHS to 1/8.
IMPORTANT: The Cyclic Prefix setting must be identical in both the BHM and the BHS.
If the settings do not match, then the BHS will not register in the BHM.
2. During installation, use Link Tests to confirm link quality per standard installation and
alignment procedures.
3. If a Link Test shows low throughput or efficiency, consider changing the Cyclic Prefix
setting to 1/4 on both the BHM and the BHS along with other standard installation
troubleshooting procedures such as re-aiming, off-axis aiming, changing location, raising
or lowering the height of the radio, and adjusting the Transmitter Output Power setting.
Installing a BH Timing Slave
Installing a PTP 100 Series BHS
Installing a PTP 100 Series (FSK) BHS consists of two procedures: