User's Manual Part 1
Release8PlanningGuide
Issue2,November2007 Draft5forRegulatoryReview 149
The collocated SM receives data in one frequency band, and the remote AP must
redistribute the data in a different frequency band. Base your selection of frequency band
ranges on regulatory restrictions, environmental conditions, and throughput requirements.
IMPORTANT!
Each relay hop (additional daisy-chained remote AP) adds latency to the link as
follows:
• approximately 6 msec where hardware scheduling is enabled.
• approximately 15 msec where software scheduling is enabled.
12.8.1 RemoteAPPerformance
The performance of a remote AP is identical to the AP performance in cluster.
Throughputs, ranges, and patch antenna coverage are identical. Cyclone Advantage and
Cyclone modules can be deployed in tandem in the same sector to meet customer
bandwidth demands.
As with all equipment operating in the unlicensed spectrum, Last Mile Gear strongly
recommends that you perform site surveys before you add network elements. These will
indicate that spectrum is available in the area where you want to grow. Keep in mind that
◦ non-LoS ranges heavily depend on environmental conditions.
◦ in most regions, not all frequencies are available.
◦ your deployments must be consistent with local regulatory restrictions.
12.8.2 ExampleUseCaseforRFObstructions
A remote AP can be used to provide last-mile access to a community where RF
obstructions prevent SMs from communicating with the higher-level AP in cluster. For
example, you may be able to use 900 MHz for the last mile between a remote AP and the
outlying SMs where these subscribers cannot form good links to a higher-level 2.4-GHz
AP. In this case, the short range of the 900-MHz remote AP is sufficient, and the ability of
the 900-MHz wavelength to be effective around foliage at short range solves the foliage
penetration problem.
An example of this use case is shown in
Figure 37.