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Nano - DV User Manual Micro-Node International
3.0 DIGITAL MODES OF OPERATION
The Nano-DV can be used with five different digital modes.
D-Star
D-Star was developed in Japan 1999/2000 especially for ham radio and
due to its clear and relative simple user interface the worldwide leading
system. Voice is being transformed by the AMBE Vocoder into a
compressed digital data stream of 3600 bits/s. In addition there is a data
channel with 1200 bits/s for a total data rate of 4800 bits/s. This data signal
modulates a carrier, so that a logical 0 is one frequency and a logical 1 a
second frequency. This is called 2FSK (two frequency shift keying) or
GMSK (which is the same, however the signal is utilized with a Gauss
curve). This signal can be used to modulate most FM transceivers (via the
packet radio socket). This is the reason why there are many homemade D-
Star solutions.
There are three D-Star reflector systems in use today.
DCS Reflectors (the system with widest use)
D-Plus REF reflectors (mostly in the English speaking countries)
X-Reflector system which plays a minor role.
Nano-DV enables communication with all three systems.
DMR
DMR is a system designed for commercial applications. This is evident in
the user interface where numbers are used in lieu of call signs. DMR
modulates with 4FSK, indicating that it uses 4 frequencies (compared to D-
Star with 2 frequencies). This allows to double the data rate to 9600 bit/s.
This higher rate allows the transmission of 2 channels at the same time (2
time slots). The DV4mini always operates in time slot 2 and in simplex
mode. The radios must be configured accordingly. Today there are two
DMR networks in use. One based on Hydra technology and the other on
Motorola. The Nano-DV checks in to the Hytera network. However if
Motorola repeaters have installed the appropriate software they can also be
reached. DMR reflectors have numbers in the range of 4000 to 5000, each
region has its own reflector which can be selected in the Nano-DV menu.