Panasonic KX-TG5771BXS, Service Manual, Page: 8 / 123

8
KX-TG5771BXS/KX-TGA570BXS
4.1.2.1. TDD Frame Format
Sync Field (72 bit): Preamble 56 bit + SyncWord 16 bit
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 (64 bit): Each kinds of DATA: ch data, line condition, etc.
B - field (320 bit + 80 bit): Sound data + parity
Z - field (4 bit): Parity Check
4.1.2.2. TDMA system
This system is the cycles of 10 ms, 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 1.25 ms, the 10 ms of voice data is transmitted.
Each slot makes every frame frequency hop. (100 hops/sec.)
Although each slot (UpLink3 and UpLink4) uses different frequency, UpLink3 and DownLink3 use the same frequency.
• 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 3000 hops (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.