PMP 400/430 and PTP 200/230 Series
Motorola PMP Solutions User Guide Supplement
Issue 6.0 May 2011
Page 45 of 77
Figure 26: Max Range & Downlink Data on AP "Configuration => Radio" page.
Suggested Control Slot settings as a function of number of SMs in the sector are shown in
Table
13
. Generally all APs in a cluster should use the same number of control slots so as to keep the
frame structures, and thereby the send and receive timing, the same.
Table 13: PMP 400/430 AP Control Slot Settings
Number of SMs that
Register to the AP
Suggested Number of
Control Slots
1 to 10
1
1
or 2
11 to 50
4
51 to 150
6
151 to 200
8
Note 1: Any OFDM sector with the
Hi Priority Channel
enabled on any SM
should be configured with at least 1
Control Slot
on the AP.
In some cases operators may find that sectors with high levels of small packet requests, such as
might be seen in a sector handling several VoIP streams, benefit overall from slightly higher
Control Slot settings. If different sectors require different numbers of Control Slots, the operator
should use the Frame Calculator to find a combination of settings that put “Rec SEQ Start” times
within 300 bit times. See section
3.7.2
on page
39
for details.
Control Slots are reserved
for SMs’ bandwidth requests and never handle data. A higher number
of control slots gives higher probability that an SM’s bandwidth request will be heard when the
system is heavily loaded, but with the tradeoff that sector capacity is reduced by about 100 kbps
for each Control Slot configured, so there will be less capacity to handle the request.
Uplink Data Slots are used first for data. If they are the not needed for data in a given frame the
data slot can be used by the SMs for bandwidth requests. This allows SMs in sectors with zero
control slots configured to still make bandwidth requests using unused data slots.
Downlink Data %, Range, and Control Slots should be set consistent with the results of any
collocation planning done using OFDM and FSK frame calculators in section
3.7.2
on page
39
.
The BHM performs its own ranging and so no range need be set for it.
BHMs do not have settings for control slots, as there is no bandwidth request contention on the
one-to-one link.
