User's Manual Part 1
Release8OverviewofCycloneNetworks
Issue2,November2007 Draft5forRegulatoryReview 90
7.1.13 2XOperation
A General tab option in both Advantage SMs and hardware series P9 and greater
Canopy SMs provides double the aggregate throughput for SMs that are nearer than half
of the maximum typical range from the AP. The requirements of this feature are as
follows:
◦ The AP must be an Advantage AP.
◦ The SM must be near the AP, roughly half the range of 1X.
◦ The SM must be of the P9 hardware series or later and enabled for hardware
scheduling. See
Designations for Hardware on Page 372.
◦ The 2X Rate parameter in the SM must be set to enabled. This is the default
setting.
◦ The amount of noise and multipath must be low enough to allow the receiver in
the 6 dB less sensitive (2X) state to maintain a high carrier-to-interference (C/I)
ratio.
The flexibility of this feature is as follows:
◦ At the time of registration, signaling is at the 1X rate. However, if the above
requirements are all met, then the SM switches to 2X.
◦ Thereafter, whenever RF conditions are unfavorable for 2X operation, the SM
switches to 1X. When favorable RF conditions allow, the SM switches back to
2X, if user data is present at that time.
◦ Similarly, whenever no user data is present, the SM switches to 1X. When user
data flow resumes, the SM switches back to 2X, if RF conditions allow.
◦ Both links for the SM (uplink and downlink) are independent for this feature.
(One can be operating at 2X operation while the other is operating at 1X.)
◦ Other SMs in the sector can be communicating with the AP at the other
modulation rate.
◦ Although subscribers with Canopy SMs realize higher bursts, and subscribers
with Advantage SMs realize both higher burst and higher sustained throughput,
the network operator realizes higher sector throughput capacity in the AP.
The effect of 2X operation on aggregate throughput for the SM is indicated in
Table 23.