PMP 400 and PTP 200 Series
Canopy User Guide Supplement
Issue 3, January 2009
Page 19 of 45
Radiated Power). This is different than the 30 dBm EIRP allowed for Canopy FSK modules
operating in the 5.4 GHz band because the regulations are for spectral power density and with
half the channel size (10 MHz vs 20 MHz), PMP 400 and PTP 200 Series radios are allowed half
the power (27 dBm vs 30 dBm).
To meet 27 dBm EIRP with the connectorized 18 dBi antenna (with 1 dB of cable loss) that
comes with the 5440AP or 5441AP, or the integrated 17 dBi antenna that comes with a 5440BH
or 5441BH, the maximum setting allowed is
10 dBm
(the default) since 27-17=10.
If a connectorized AP or BHM has been purchased and the operator has provided the antenna,
the Transmitter Output Power must be configured based on that antenna and consistent with
local or regional regulations. For example, if a 5440APC is being used with a 12 dBi antenna,
then the maximum setting allowed to meet 27 dBm EIRP is the full 15 dBm of which the radio is
capable, since 27-12=15.
IMPORTANT!
It is the responsibility of the operator and professional installer to ensure
Transmitter Output Power is set within regulatory limits for their country
or region. These must be set or confirmed on initial configuration and
after a module is reset to factory defaults, and should be confirmed after
the software on a module is upgraded.
In most cases, the operator will want to set the AP’s Transmitter Output Power to the maximum
allowed so as to have the greatest overall range and the greatest range for 3X operation. It may
be useful to reduce Transmitter Output Power when Canopy systems are located close together,
with good coverage given because of their proximity and full power isn’t needed, or in cases
where an operator is trying to reduce interference from the Canopy system to other systems.
Each SM’s Transmitter Output Power is automatically set by the AP, not by the operator. The
AP’s Auto-TPC (Transmit Power Control) sets each SM’s Transmitter Output Power to the lesser
of
•
10 dBm for a 5.4 GHz radio, the maximum allowed on the SM since it has an
integrated 17 dBi antenna and a regulatory maximum EIRP of 27 dBm (27-17=10)
•
18 dBm for a 4.9 GHz radio
•
a power level so that the received power at the AP from that SM is not greater than
60 dBm.
PMP 400 Series networks use Auto-TPC because OFDM technology is more sensitive to large
differences in power levels from SMs operating at various distances from the AP than the single
carrier technology used in Canopy FSK.
PTP 200 Series networks do not use Auto-TPC – the operator sets Transmitter Output Power on
the “Configuration => Radio” page of both the BHM and the BHS.
PMP 400 and PTP 200 Series modules display the typical Canopy “Receive Power Level” but
due to the different modulation technique no “jitter” is calculated or displayed.
4.3
DOWNLINK DATA %, RANGE, AND CONTROL SLOTS
The Downlink Data % parameter on the AP’s and BHM’s “Configuration => General” page can be
set in 1% increments between 10% and 90%. (Standard Canopy can be set between 1% and
99%, although internal calculations don’t result in that extreme of slot assignment between uplink
and downlink.) The default is 75%, the same as standard Canopy.
