Samsung Office DECT 8000, Installation And Programming Manual

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1–3
DECT Time Slot and Frame Structure
•
1 DECT FRAME : 10mS
•
1 DECT SLOT : 417µS (480bit)
•
1 DECT Bit : 868nS
Basic Functions of the DECT System
DECT System DECT System DECT System DECT System
!
The DECT system uses a pico-cellular technology (the cell range is 15 m to 300 m depending
on the environment).
!
The frequency ranges between 1,880 and 1,900MHz (UHF); i.e. 20MHz is shared out into 10
carriers.
!
The pass-range of a channel is equal to 1.728MHz and two channels are separated by 2MHz
in order not to disturb the neighbouring channels.
DCS System
DCS System DCS System
DCS System
The DCS system:
! controls and maintains the BSI;
!
maintains and downloads DBS functions;
! controls the data from the DECT handset, and sends display data to the DECT handset.
DBS
DBS DBS
DBS
! A DBS uses one of 10 channels (FDMA technology) and 24 time slots per frequency (TDMA
technology).
! GFSK (Gaussian Frequency Shift Keying) modulation technology is used.
BSI
BSI BSI
BSI
The BSI:
! maintains subscriber information and communicates with the DCS system;
!
handles fault information.
1 TDMA frame 24 timeslots (10mS)
Fix to Portable Portable to Fix
0 1 2 3 4 5 6 7 8 9 10 11 0 1 2 3 4 5 6 7 8 9 10 11
417µs
28µs 340µs 49µs
Guard-Space(56bits) D-Field(388bits)
Z
Sync,-Field(32bits)
56µs 278µs 3µs 3µs
Z-Field (4bits) X-Field (4bits) B-Field (320bits) A-Field (64bits)
SLOT
D-Field
I-Field (320bits) CRC (16bits) Tail (40bits) Header (8bits)
FRAME