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Serial Multiservice Interface Module Overview

CTP bundles are supported on the Serial Multiservice Interface module. CTP bundles on Multiservice Interface modules can operate with the following modes:

  • Audio—Provides single and dual channel audio support for varying quality audio from 8-bit, 8-KHz quality to 8-bit up to 16-bit, 48-KHz quality (CD quality).
  • 4WTO—Provides single and dual channel audio support for 8-bit, 8-KHz quality with squelch support for radio backhaul. In 4WTO mode, the Multiservice Interface module is interoperable with 4WTO daughter cards.
  • IRIG—Enables an interrange instrumentation group time code (IRIG-B) signal to be transported through an IP network.
  • TDC—Provides combined time-correlated support for IRIG/NRZ data for telemetry applications.

Audio Mode

Audio mode provides a high-quality audio (CD quality) interface. Audio mode supports the following features:

  • One or two simultaneous channels.
  • Codec sampling rates up to 48 KHz.
  • Optional μ-law encoding and decoding.
  • Embedded frame requiring no additional bandwidth.
  • Configurable output level from 0x to 2x.
  • Signaling capability with talk squelch.

Figure 1 shows the cable pinouts and the data flow when the Multiservice Interface module operates in audio mode.

Figure 1: Cable Pinouts and Data Flow When the Multiservice Interface Module Operates in Audio Mode

Cable
Pinouts and Data Flow When the Multiservice Interface Module Operates
in Audio Mode

4WTO Mode

The CTP 4-wire trunk only (4WTO) analog option provides encoding for one or two analog voice channels into a single CTP IP data stream.

4WTO mode supports the following features:

  • One or two simultaneous channels.
  • Codec sampling rate of 8 KHz.
  • Optional μ-law encoding.
  • Signaling capability with talk squelch.
  • Configurable output level from 0x to 2x.
  • Interoperability with a 4WTO daughter card. Interoperability is supported only on daughter cards that have firmware revision 4 or later. You enable interoperability in the 4WTO daughter card configuration by setting MS interwork to enabled.

IRIG Mode

The Multiservice Interface module enables an interrange instrumentation group time code (IRIG-B) signal to be transported through an IP network. The IRIG-B standard consists of a family of rate-scaled serial time codes with formats containing up to three coded expressions or words. The IRIG-B pulse code contains one frame of 100 elements per second for the time of the year and GPS receiver status. IRIG-B encodes day of year, hour, minute, and second data on a 1-KHz carrier frequency, with an update rate of once per second.

IRIG-B mode supports the following features:

  • IRIG-B transported at rates between 1 Kbps and 25.5 Kbps.
  • Configurable output level from 0 to 7.85 volts peak-to-peak based on a 50-ohm termination.

TDC Mode

Time domain correlation (TDC) mode supports special applications in which digital data (NRZ) needs to be closely time correlated with a timing signal (IRIG-B). In TDC mode, the IRIG-B signal is transported on an 8-KHz audio path, and the NRZ data is transported using RTS/DTR (NRZ input) and CTS/DSR (NRZ output). Circuitry on the Multiservice Interface module accepts these two streams and combines them into a single digital data stream that is carried through the IP network in one direction, while making sure that the time relationship between the two signals is closely maintained.

Here is a list of the features of the TDC transport function:

  • IRIG-B transported at 8-KHz with 16-bit samples; that is, no companding.
  • NRZ data rates supported from 0.5 KHz to 5000 KHz in 0.5 KHz steps.
  • Embedded frame requiring no additional bandwidth.
  • Configurable IRIG-B output level from 0x to 2x.

Figure 2 shows the cable pinouts and the data flow when the Multiservice Interface module operates in TDC mode.

Figure 2: Cable Pinouts and Data Flow When the Multiservice Interface Module Operates in TDC Mode

Cable Pinouts
and Data Flow When the Multiservice Interface Module Operates in TDC
Mode

Modified: 2015-11-17