Hytera PD70X Series, Руководство по планированию систем

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Hytera DMR System Planner
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2.7.4 Performance while Roaming
Please note that roaming may cause performance degradations. Therefore, the
RSSI threshold and the terminal’s Site Lock must be set appropriately when not in
mobile status. The degradations are similar to what the terminal will experience
during scanning. Degradation may occur in the following:
ˆ Late entry to voice transmission
ˆ
Longer preamble required for control message and data
ˆ Increased setup time for Confirmed Private Call
ˆ Group Call Time to Talk Permit may increase if auto site roaming is required
During roaming, the terminal will temporarily leave the current home channel and
detect other sites (similar to scan). This means the terminal may not be present on
the master site when a call starts. After detecting every other site, the terminal will
detect the master site to minimize the time away from it. This is similar to the
scanning order for a priority member.
If the current master site cannot be revived, the terminal will try to locate another site
via the automatic active site roaming. When the terminal tries to revive other sites,
the user must wait. This increase in time will be recognized as an increase in the
time from PTT to receiving the Talk Permit Tone. This will not occur often if the
beacon interval for the repeater is appropriately set.
It is expected that the value that the Roaming feature adds is worth these
performance degradations. The beacon interval and the RSSI threshold should be
appropriately set to minimize the time the terminal needs to search for a site.