Motorola 4940AP, Supplement To User’S Manual

Page: 13 / 45

PMP 400 and PTP 200 Series Canopy User Guide Supplement
Issue 3, January 2009 Page 13 of 45
3 Planning
PMP 400 and PTP 200 Series systems use a 10 MHz channel size configurable on 5 MHz
centers. This channel size, along with some different characteristics due to the use OFDM carrier
technology and QPSK, 16 QAM, or 64 QAM modulation, supports somewhat different channel
planning than for standard Canopy. (For reference, PMP 100/200 Series uses 20 MHz channels
configurable on 5 MHz centers, single carrier technology, and 2-level and 4-level FSK
modulation.)
3.1 TOWER CHANNEL PLANNING
For a single cluster of 4 APs on a tower, 2-channel re-use with channels on 10 MHz channel
center spacing gives good performance. In channel design parlance, this can be stated as ABAB
channel planning, with no guard band needed between A and B. A typical arrangement might be
to use radios configured for 5480 MHz aimed north and south, and radios configured for 5490
MHz aimed east and west.
(For reference, standard Canopy uses 2-channel re-use with clusters of 6 APs on a tower with
channel center spacing of either 25 MHz for Advantage APs or 20 MHz for non-Advantage APs.
This is ABCABC channel planning, with 5 MHz guard band between the 20 MHz channels for
Advantage APs and no guard band needed for non-Advantage.)
Available 5.4 GHz channel center frequencies for each region are shown in Table 3. These vary
by region due to
•
different band edge RF specifications (for example, between Canada/US and
Europe)
•
requirements in Europe and Canada to not impinge on the frequencies between 5600
and 5650 MHz, which are frequencies on which some weather radar operate
Table 3: 5.4 GHz Channel Center Frequencies, by Region
Region
Range of Center Frequencies
Available (MHz)
(on 5 MHz centers within this
range, inclusive)
Maximum number of
non-overlapping
channels
US 5480 - 5710 24
Canada 5480 – 5595, 5655 - 5710 18
Europe 5475 - 5595, 5655 - 5715 20
US FSK (for comparison) 5495 - 5705 11
Canada FSK (for
comparison)
5495 - 5575, 5675 - 5705
7
Available 4.9 GHz channel center frequencies are shown in Table 4.
Table 4: 4.9 GHz Channel Center Frequencies
Range of Center Frequencies
Available (MHz)
(on 5 MHz centers within this
range, inclusive)
Maximum number of
non-overlapping
channels
4945 - 4985 5