User Manual

10
2 PRODUCT DESCRIPTION
The M-803 digital mobile radio is a hardware component of the OpenSky
®
network, an integrated voice and data communications system that delivers
end-to-end digital transmissions over a single wireless network to the dash-
mounted or trunk-mounted radio receiver.
The M-803 is intended to operate in a mobile environment, typically a motor
vehicle. The radio operates over both the Specialized Mobile Radio (SMR)
and National Public Safety Planning Advisory Committee (NPSPAC)
frequency bands. These bands provide more than 840 possible channels spread
over the 806-824 MHz transmit and 851-869 MHz receive bands. The M-803
operates half-duplex with a 15W (typical) transmit output power. Optional
full-duplex operation is also available.
The M803 is available in four hardware configurations, three of which are
further defined for data operation as half- or full-duplex:
• Dash mount with built-in control head. Additional remote control heads
can be added (half- or full-duplex).
• Trunk mount with a single or multiple remote control heads (half- or full-
duplex).
• Data only – No control head (half- or full-duplex, PC required).
• V-TAC Full Duplex Vehicle Repeater with a one or more remote control
heads.
The M-803 uses Time Division Multiple Access (TDMA) technology to allow
multiple users to share a single RF channel. In addition, a single RF channel
can support simultaneous digital voice and data communications. The V-TAC
takes advantage of OpenSky’s TDMA ability to minimize interference
between its local and network radio links when operating in an Extended
Coverage mode (XCOV or XCOV-TG), an undesirable characteristic of many
traditional vehicular repeater systems.
The M-803 provides integrated voice and data services. Voice operation is
provided using a microphone and speaker included in the radio installation kit.
For data transfers, the M-803 is constructed with an industry-standard RS-232
interface serial port for connecting an optional laptop PC.
A PC, not included with the M-803, provides network connectivity through
the standard serial (DTE-type) interface.
The M-803 is a “soft” radio. Its functions are determined by the software
applications installed.
The optional GPS tracking devices embedded in M-803 radios can provide
quick and accurate positional information to a connected laptop locally in the
vehicle. GPS can also provide positional information over the radio link, if
configured to do so.