P25 - Catalyst Communication Technologies

Modern Standards – P25

Project 25 is a series of living standards from the TIA TR-8 Committee, which is made up of customer representatives from federal, state, and local public safety organizations. The Project 25 standards are developed under the guidance of the Telecommunications Industry Association (TIA) whose standard formulating committees include manufacturer representatives. TIA standards are developed using open procedures that are required by the American National Standards Institute (ANSI).

Catalyst’s scalable solutions provide Project 25 voice dispatch, interoperability and incident command using three multi-vendor standards, each providing Unit ID & Emergency.

Console Sub-System Interface (CSSI)

The Console Subsystem Interface (CSSI) connects a Console Subsystem (CSS) to a Radio Frequency Sub System. Typically, this interface is used for trunked P25 systems or for complex conventional P25 systems, although Catalyst has used this interface to connect with LTE cellular networks, demonstrating the flexibility of this interface. Catalyst implements the P25 CSSI interface through gateway software technology that provides a direct Ethernet interface to various radio manufacturers’ P25 switch infrastructure via that manufacturer’s CSSI gateway. Multiple simultaneous audio paths can be routed through the Catalyst CSSI Gateway to provide a more robust solution compared with wireless system donor radio scanning.

Digital Fixed Station Interface (DFSI)

The P25 Digital Fixed Station Interface (DFSI) connects conventional P25-base stations or repeaters to a Radio Frequency Sub System. Catalyst implements the P25 DFSI interface through gateway software technology that provides direct Ethernet interface to up to four P25 conventional base stations, providing P25 digital audio, conventional audio, and control for IDs, emergency, and direct access to up to thirty-two channels.

P25 Control Station Interface

Catalyst provides advanced control of P25 control stations or mobile radios from several vendors.

The features available using P25 control stations vary by radio model. A few examples are:

  • Remotely send radio voice via IP Network from Console to radio gateways
  • Have remote Push-to-Talk (PTT) Control of radios attached to radio gateways
  • Receive Unit ID of subscriber radios talking to gateway radios
  • Have remote direct access to 100s of channels programmed into gateway radio
  • Hear the channel grant message with remote PTT of gateway radio
  • Receive end-of-call message from gateway radio
  • Display selected channel ID with text and/or graphics
  • Display received channel ID with text and/or graphics
  • Receive indication of a queued call on the network
  • Display on screen when a transmitter is off-line
  • Remotely select Zone or System
  • Put the radio attached to the gateway into and out of scan mode
  • Instigate a private call
  • Patch a P25 radio channel to other radio systems like SmartNet/SmartZone, DMR, and EDACS
  • Send Unit ID of subscriber radios from other radio systems to P25 subscriber radios

IWCE 2022: Standing up a remote dispatch system ‘doesn’t happen overnight’ We moderated a panel on Work From Home Alternatives for Dispatchers – what the pandemic taught us. IWCE's Andy Castillo was present for the action and filed this report. blog.catcomtec.com/2022/03/24…