Configuring - Motorola 5440AP - Canopy 5.4 GHz AP User Manual Supplement

Canopy 400 Series OFDM AP and SM User Guide

4 Configuring

Most Canopy Series 400 configuration items are identical or very similar to configuration items in
standard FSK Canopy modules. This section will discuss those that are new or changed and also
remark on some that remain unchanged.
4.1 LINK OPERATION – 1X/2X/3X
Canopy 400 Series products offer three levels or speeds of operation – 1X, 2X, and 3X - instead
of the two levels offered by standard Canopy. 3X supports a typical maximum aggregate (sum of
up and down) throughput of 21 Mbps at up to 1.25 mi (~1 km). If received power is less due to
distance between the AP and the SM or due to obstructions, or interference affects the RF
environment, the Canopy system will automatically and dynamically adjust links to the best
operation level. Distance, rates and other information associated with the operation levels are
shown in Table 1 on page 11.
Similar to standard Canopy, the system chooses its operation rate dynamically, based on
Canopy's internal ARQ (Automatic Repeat reQuest) error control method. With ARQ, every data
slot of every frame sent over the air is expected to be acknowledged by the receiver, and if
acknowledgement is not received, the data is resent. The sending unit monitors these resends,
and adjusts the operation rate accordingly. A normal system may have links that move from 3X to
2X and back (or 1X) as the RF environment changes, or links. Furthermore, the links operate
independently, and it is normal, for example, for the downlink to run a 3X while the uplink RF
environment only supports 2X.
The default is for both AP and SM to be enabled for 3X operation. An operator may "lock down" a
link to 2X and 1X operation, or to only 1 X operation, using the Dynamic Rate Adapt parameter on
the SM's "Configuration => General" page as shown in Figure 3 on page 15 . This parameter
locks down both uplink and downlink operation. An operator may lock down an entire sector to 2X
and 1X operation, or to only 1 X operation, using the Dynamic Rate Adapte parameter on the
SM's "Configuration => General" page. This parameter locks down uplink and downlink of all links
in the sector, and overrides any SM 1X/2X/3X settings. That is, if an individual link is set for 3X
operation at the SM, but the sector is set for 1X operation at the AP, that link (and all links in the
sector) will be locked down to 1X operation.
Version 1, April 2008 Page 15 of 40