TIA-102.BAHA:2006

This document defines a Conventional Fixed Station Interface
(CFSI). The CFSI is the interface between a conventional fixed
station, which is defined in this document as a functional
component of a Fixed Station Subsystem, and a Conventional Fixed
Station Host (CFSH). A CFSH is defined in this document as a
functional component of either an RF Subsystem (RFSS) or a Console
Subsystem.¹ Clause 6 describes these elements and their
relationship to each other. For the purposes of this scope
statement, a fixed station may be either an "analog fixed station"
or a "digital fixed station". An "analog fixed station" supports
conventional FM RF resources or their equivalent. A "digital fixed
station" supports the P25 Common Air Interface (CAI) for P25
conventional systems (see [8]).

This document fully describes the CFSI including its
architecture (clause 6), and protocols (clauses 7 and 8). Clause 7
describes a basic analog audio and control interface, while clause
8 describes a more capable Internet Protocol (IP) (see [1]) based
digital interface. This interface has been designed to work with
IPv4. Use of this interface with IPv6 is for further study.

The functional scope of the CFSI as described herein comprises
the following CFSI Analog and CFSI Digital Interface
provisions.

The CFSI Analog Interface provides:

1. Transport of clear audio between a fixed station and its
host² providing capabilities for full-duplex,
half-duplex and simplex communications at the discretion of the
fixed station.

2. Transport of E&M control signaling between a fixed
station and its host to provide a simple "Push-to-talk" and "COR"
capability.

3. Transport of Tone Remote Control (TRC) control signaling from
a host to a fixed station to provide a variety of control functions
including transmit channel control, squelch control, monitor
control, clear/secure controls, analog/digital mode controls,
etc.

4. A primitive "Intercom" capability allowing for the transport
of audio between the fixed station and its host without initiating
an RF transmission.

The CFSI Digital Interface provides:

1. IP based capabilities equivalent to those provided via the
Analog Interface.

2. Transport of encrypted audio between a digital fixed station
and its host.

3. Transport of Caller-ID information between a digital fixed
station and its host. This includes Unit ID from field units to
consoles, and "Console ID" from consoles to field units.

4. Transport of Talk-group information between a digital fixed
station and its host.

5. Transport of NAC code information between a digital fixed
station and its host.

6. Transport of Emergency Alert messages from the digital fixed
station to its host.

7. Transport of Emergency indications along with the voice
stream between the digital fixed station and its host.

8. Transport of Received voter identification from the digital
fixed station to its host.

9. Advanced Control of the Fixed Station by its host including
the disabling of all squelch (monitor function).

10. A standard option to transport intercom audio to and from
the fixed station location.

¹For the purposes of this document the CFSI is
defined as a specialization of the generic Project 25 Fixed Station
Interface (FSI) described in TSB102-A (see [19]).

² Throughout this document the terms "Host" or "host"
refer to the CFSH as defined in this document.