Mhz System Operation; Access Method; Protocol - Sony SPP-S9101 Service Manual

3-1. ACCESS METHOD

1. Transfer Format & Rate
The transfer format & rate of our system is as follows;
Table 3-1. Transfer method
Access method FDMA-TDD
Channel number 14 channel
Channel spacing 1.2 MHz
Modulation method DBPSK
Baseband transfer rate 960 Kbps
Spread method Direct Sequence Spread Spectrum
Chip rate 12 chips/bit
Data transfer rate 80 Kbps
2. Channel Number & Frequencies
RF channels occupy the frequency band 902 – 928 MHz are num-
bered 1 to 14.
RF channel numbers & center frequencies are specified as fol-
lows.
Table 3-2. Channel number & Channel frequency
Channel Channel Center Frequency (MHz)
Number UNIT CH PLAN
1 907.2
2 908.4
3 909.6
4 910.8
5 912.0
6 913.2
7 914.4
8 915.6
9 916.8
10 918.0
11 919.2
12 920.4
13 921.6
14 922.8
15
16
17
18
19
20
*Note) The UNIT has 14 channels according to the UNIT CH
PLAN while the number of channels which can be used in
the test mode are those in the TEST MODE CH PLAN.
SECTION 3

900 MHz SYSTEM OPERATION

TEST MODE CH PLAN
904.2
904.8
906.0
907.2
908.4
909.6
910.8
912.0
913.2
914.4
915.6
916.8
918.0
919.2
920.4
921.6
922.8
924.0
925.2
925.8

3-2. PROTOCOL

1. General
This system realizes the TX/RX superframe by TDD system. The
relation of master/slave dose not decide identification regarding
the protocol between BASE UNIT and HANDSET, but the initi-
ated side is the master and the requested side is the slave when the
RF link has been established.
2. Initial Acquisition
In order to establish the RF link between BASE UNIT and HAND-
SET, both of BASE UNIT and HANDSET need to have the same
system ID. When "power" is applied to this system, the system
have to do Initial Acquisition in order to have the same system ID.
It is to exchange a parameter when the HANDSET is parked on
the BASE UNIT, as soon as the system do System Parameters Re-
initialization.
3. System Parameter Re-initialization
This System Parameters Re-initialization can realize that the
HANDSET is parked on the BASE UNIT. So after the BASE UNIT
recognized to be parked the HANDSET, the BASE UNIT calcu-
lates a system parameter, and then it outputs this data from the
ARTO port, and then the system establishes the RF link. In order
to establish this link, the HANDSET send the A-Frame to the BASE
UNIT after the HANDSET received the system parameter, and
then the BASE UNIT send the A-Frame to the HANDSET. The
process of System Parameters Re-initialization is as follows.
BASE UNIT
(Park Detect)
System Parameters
A-Frame
System ID
confirmed
A-Frame
Fig. 3-1. System Parameters Re-initialization
HANDSET
(PARK)
(Park Detect)
System ID
confirmed
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