# US 5,706,336 A · Telephone system circuitry for discriminating between voice and data transmissions

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- Number: US 5,706,336 A
- Document ID: US5706336A
- Status: Granted
- Kind: A
- Application number: 08/548,449
- Filed: 1995-10-26
- Granted: 1998-01-06
- Earliest claimed: 1995-06-30
- Assignees: Elonex I.P. Holdings, Ltd.
- Inventors: Dan Kikinis
- Web page: https://patentgrep.com/patent/US5706336A

## CPC

- H04M 3/428: Arrangements for placing incoming calls on hold
- H04M: TELEPHONIC COMMUNICATION (circuits for controlling other apparatus via a telephone cable and not involving telephone switching apparatus G08)

## Abstract

A selective call-waiting system for telephony use samples transmission on a busy line if the line subscribes to the selective call-waiting service, and avoids interrupting the transmission with a call-waiting signal if the transmission is data-type. If the transmission on the busy line subscribing to the selective call-waiting service is voice-type, the system sends a call-waiting signal. Signal analyzers are disclosed, as well as methods for practicing the invention.

## Claims

### Claim 1

A signal-analyzer plug-in card comprising:
an interface adapted for connecting to a subscriber line interface circuit (SLIC);
discrimination circuitry coupled to the interface and adapted for determining between voice signals and data signals in an ongoing established communication between two active terminals; and
a digital communication port adapted for communication with a CPU;
wherein the discrimination circuitry determines the voice or data nature of the established communication, and communicates the voice or data nature to the CPU via the digital communication port.

### Claim 2

A line card for a telephone switching system, comprising:
a first interface for connecting the line card to a time-slot switch (TSS) and a second interface for connecting the line card to a subscriber line; and
discrimination circuitry coupled to the second interface and adapted for determining between voice signals and data signals in an ongoing communication;
wherein the line card is adapted to communicate with a CPU through the TSS to inform the CPU on command of voice or data nature of telephone signals carried by the line card.

### Claim 3

A trunk card for a telephone switching system, comprising:
a first interface for connecting the trunk card to a time-slot switch (TSS) and a second interface for connecting the trunk card to a trunk; and
discrimination circuitry coupled to the second interface and adapted for determining between voice signals and data signals in an ongoing communication;
wherein the trunk card is adapted to communicate with a CPU through the TSS to inform the CPU on command of voice or data nature of telephone signals carried by the trunk card.