User's Manual

13
SPECIFICATION
SC14435 2G4HZ Frequency hopping
The number of used frequencies (NUF) in the hopping algorithm is 95.
In base and handset a Primary Hopping lndex Number (PHIN) exist.
This number is incremented modulo NUF in the end of the normal downlink
half-frame. It is broadcast in Q0 message instead of PSCN.
To a simplex or established duplex bearer a Hopping Index Offset (HIO) is
assigned, which is an analogue to the used RF carrier in a FDMA system. This
value is broadcast in place of CN in Q0 message. In the base in all unable
slots in up-link direction the receiver is scanning with HIO=0. the receiver is
scanning with doesn’t exclude RF-carriers.
Different base use different hopping sequences. The different sequences are
derived from the hopping table by adding an offset, SeQuenceCode(SQC).
A hopping table maps an index I to a carrier number: CN = f(I)
The physical RF carrier is calculated by the formula:
CN = (f ((PHIN+HIO) mod NUF) +SQC )mod NUF for 10.368000 MHz crystal
frequencies are derived as: Frequency : 2401.056 MHz + CN*0.864000 MHz
Fast Frequency Hopping : (DCT 2G4) , up to 800 hops/sec
This equipment is made for report by two-way radio in place of business.