User's Manual

Lane Tuning Guidelines
4-7
• The downlink and uplink source frequencies and interference from lanes sharing
same or close frequencies
• The antenna-tag orientation
RF power is the most important RF factor in lane tuning. Thirty dBm translates to one-
watt nominal power. Increasing the RF power will, in general, increase the footprint.
There are other factors involved such as antenna angle and placement that may affect
the footprint, but increasing RF power will generally increase the signal and increase
both the footprint and the RF margins in the lane.
Because the RF power can create interference in adjacent or nearby lanes and degrade
the performance of the adjacent lane, the RF power should be adjusted so that mini
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mum power is used to achieve the desired results.
Downlink and Uplink Transmitted RF Power
Downlink signal is the signal transmitted from the reader to the tag, and uplink signal
is the signal reflected back to the receiver from the tag. The impact of the downlink
and uplink power on footprint and lane performance is heavily dependent on the pro
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tocol type(s) in use in the lane. Table x-x (to be provided) is a general guide to the
influence of RF power on the footprint by protocol. Some of these factors are interre
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lated to such aspects as antenna angle, antenna placement, and tag placement, so use
this information as a starting point and consider other aspects of lane tuning when
operating on any given lane.
Both downlink and uplink power are adjustable by tag protocol. In other words, in
multiple protocol systems, the RF power can be adjusted for each tag protocol in use,
independent of the other tag protocol.
Range Control Adjustments
Adjusting the range control allows the user to adjust the footprint separate from any
setting of the RF power. It is an adjustment on the sensitivity of the receiver and is
done independently for each tag protocol. The units are in decibels and vary from 0 to
20dB, with the higher number giving the smaller footprint. Range control always
exerts an effect on the footprint and performance separate from the tag protocol, but
the degree of the effect may be dependent on RF power and antenna parameters as
well. The most common use of range control is in multiple protocol situations, where
the first read point of tags with two differing protocols must be made to coincide
within a lane. In this situation, the power and antenna parameters are adjusted so that
the weaker protocol tags are reading at the appointed position, then range control is
used to adjust the first read point of the stronger protocol tags down to the same posi
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tion as the other protocol. Range control can also be used in a single protocol situation
to fine tune the first read position.
Frequency Considerations — Single Protocol
TBD
IT2200 or Title 21 Tag Protocol
TBD
This uplink frequency separation should repeat for additional lanes.
eGo Tag Protocol
TBD