Panasonic KX-TG5571BXM, Service Manual

Page: 58 / 128

9.2.1. TDD Frame Format
Sync Field (72bit): Preamble 56bit + SyncW ord 16bit
Base Unit (Handset) adjusts the timing of reception so that reception of Base Unit (Handset) can correspond to transmission
of Handset (Base Unit).
It is necessary for sync-field that Handset gets synchronization.
A - field (64bit): Each kinds of DATA: ch data, line condition, etc.
B - field ( 80bit): Sound data + parity
Z - field (4bit): Parity Check
9.2.2. TDMA system
This system is the cycles of 10ms, and has four duplex paths, so it is possible to perform four duplex communications
simultaneously.
(Up to eight Handsets can be registered)
In 1 slot 1.25ms, the 10ms of voice data is transmitted.
Each slot makes every frame frequency hop. (100hops/sec.)
Although each slot (UpLink3 and UpLink4) uses different frequency, UpLink3 and DownLink3 use the same frequency.
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2 - Handsets Link
Traffic Bearer
A link is established between Base Unit and Handset.
The state where duplex communication is performed.
The hopping pattern of a 3000hops (30 seconds) cycle.
Dummy Bearer
The Base Unit sends Dummy-data to the all stand-by state Handsets.
The Handsets receive that data for keeping synchronization and monitoring request from the Base Unit.
Dummy Bearer doesn´t contain B-field (sound) data.
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KX-TG5571BXM / KX-TGA550BXM