Codan Radio P25 Training Guide - Manual (Page 28)

TRAINING GUIDE | P25 RADIO SYSTEMS
Chapter 2: P25 Interface Standards Page 20
DATA PERIPHERAL INTERFACE
The Data Peripheral Interface (A) defi nes protocols by which mobile and portable subscriber units will
support a port through which laptops, terminals, or subscriber unit peripherals may be connected. It is
required that the supported open interface protocols are passed transparently into X.25, SNA, or TCP/
IP computer networks at another open interface on the fi xed equipment side. Transparency is listed as
a requirement, and it is expected that application layer standards emerge for the connection of various
peripheral devices.
FIXED STATION INTERFACE
The Fixed Station Interface provides for communication between a Fixed Station (FS) and either an RF
Sub-System (RFSS) or a Console Sub-System.
The Fixed Station Interface defi nes a set of mandatory messages, supporting analog voice, digital
voice (clear or encrypted), and data (under development). These messages will be of a standard
format passed over the interface. Manufacturers can enhance this functionality using manufacturer
specifi c messages.
The Conventional Fixed Station Interface (CFSI), which is a specialization of the Fixed Station Interface,
has been defi ned. A breakdown of the information contained in the CFSI can be found in Chapter 5:
Conventional Fixed Station Interface.
The CFSI defi nes both an Analog Fixed Station Interface (AFSI) and a Digital Fixed Station Interface
(DFSI). Either one of these interfaces can be used to connect to a fi xed station operating in analog,
digital or mixed mode.
The AFSI confi guration is 2 or 4-wire audio with E&M or Tone Remote Control.
The DFSI confi guration is an IP based interface. The physical interface is an Ethernet 100 Base-T
with an RJ45 connector. The DFSI utilizes UDP for control information and RTP on UDP for voice
information. Digital voice information is IMBE™ and analog voice information is PCM audio.