Voice and data transmission system

• US 5,500,859 A
• Filed: 08/11/1994
• Issued: 03/19/1996
• Est. Priority Date: 01/08/1993
• Status: Expired due to Term

• Current Assignee: Multi-Tech Systems Incorporated
• Original Assignee: Multi-Tech Systems Incorporated
• Inventors: Davis, Jeffrey P., Li, Ping, Sharma, Raghu, Gunn, Timothy D.
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): Nguyen, Chau T.
• Application Number:
  US08/289,304
• Time in Patent Office: 586 Days
• Field of Search: 370/80, 370/81, 370/110.1, 370/112, 370/79, 370/111, 370/118, 370/109, 370/24, 370/31, 370/94.1, 379/93, 379/96, 379/97, 379/98, 379/90, 379/100, 379/410
• US Class Current: 370/468
• CPC Class Codes: G10L 19/04 using predictive techniques
• CPC Class Codes: H04L 12/6418 Hybrid transport
• CPC Class Codes: H04L 2012/6424 Access arrangements
• CPC Class Codes: H04L 2012/6427 Subscriber Access Module; Concentrator; Group equipment
• CPC Class Codes: H04L 2012/6459 Multiplexing, e.g. TDMA, CDMA
• CPC Class Codes: H04L 2012/6475 N-ISDN, Public Switched Telephone Network [PSTN]
• CPC Class Codes: H04L 2012/6481 Speech, voice
• CPC Class Codes: H04L 2012/6491 Echo cancellation
• CPC Class Codes: H04L 2012/6494 Silence suppression
• CPC Class Codes: H04L 27/3416 in which the information is carried by both the individual signal points and the subset to which the individual points belong, e.g. using coset coding, lattice coding, or related schemes
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/762 at the source reformatting of additional data in video distribution servers H04N21/2355
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04L 69/04 Protocols for data compression, e.g. ROHC
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: H04M 1/247 Telephone sets including user guidance or feature selection means facilitating their use user interfaces specially adapted for cordless or mobile telephones H04M1/724
• CPC Class Codes: H04M 1/2473 Telephone terminals interfacing a personal computer, e.g. using an API (Application Programming Interface) details of API H04M7/0021
• CPC Class Codes: H04M 1/2477 for selecting a function from a menu display H04M1/2474 takes precedence
• CPC Class Codes: H04M 1/253 Telephone sets using digital voice transmission
• CPC Class Codes: H04M 1/57 : Arrangements for indicating or recording the number of the calling subscriber at the called subscriber's set at the operator set in a manual exchange H04M5/20
• CPC Class Codes: H04M 1/6033 : for providing handsfree use or a loudspeaker mode in telephone sets arrangements for preventing acoustic echo H04M9/08
• CPC Class Codes: H04M 1/6505 : storing speech in digital form
• CPC Class Codes: H04M 1/663 : Preventing unauthorised calls to a telephone set
• CPC Class Codes: H04M 11/06 : Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors
• CPC Class Codes: H04M 11/064 : Data transmission during pauses in telephone conversation
• CPC Class Codes: H04M 11/068 : using time division multiplex techniques; integrated services digital networks H04Q11/0428
• CPC Class Codes: H04M 2203/4509 : Unified messaging with single point of access to voicemail and other mail or messaging systems unified messaging in packet switching networks H04L51/56
• CPC Class Codes: H04M 3/002 : Applications of echo suppressors or cancellers in telephonic connections in two-way loud-speaking telephone systems H04M9/08, echo suppressors or cancellers per se H04B3/20
• CPC Class Codes: H04M 3/42 : Systems providing special services or facilities to subscribers specially adapted for wireless communication networks H04W4/00
• CPC Class Codes: H04M 3/436 : Arrangements for screening incoming calls , i.e. evaluating the characteristics of a call before deciding whether to answer it based on the calling party profile H04M3/42059; based on location H04M3/42348; based on presence H04M3/42365; diversion H04M3/54
• CPC Class Codes: H04M 3/5307 : for recording messages comprising any combination of audio and non-audio components
• CPC Class Codes: H04M 3/533 : Voice mail systems
• CPC Class Codes: H04M 3/567 : Multimedia conference systems
• CPC Class Codes: H04M 7/0027 : Collaboration services where a computer is used for data transfer and the telephone is used for telephonic communication
• CPC Class Codes: H04M 7/0057 : Services where the data services network provides a telephone service in addition or as an alternative, e.g. for backup purposes, to the telephone service provided by the telephone services network
• CPC Class Codes: H04M 7/006 : Networks other than PSTN/ISDN providing telephone service, e.g. Voice over Internet Protocol (VoIP) , including next generation networks with a packet-switched transport layer H04L65/00 takes precedence; aspects not specific to the type of network H04M3/00; special services in those networks H04M3/42
• CPC Class Codes: H04M 7/1295 : Details of dual tone multiple frequency signalling
• CPC Class Codes: H04N 1/00204 : with a digital computer or a digital computer system, e.g. an internet server programmed control between transmitter and receiver or between image input and image output device H04N1/32561
• CPC Class Codes: H04N 1/00206 : Transmitting or receiving computer data via an image communication device, e.g. a facsimile transceiver H04N1/00236 takes precedence
• CPC Class Codes: Y10S 379/908 : Multimedia

Abstract

A personal communications system is described which includes components of software and hardware operating in conjunction with a personal computer. The user interface control software operates on a personal computer, preferably within the Microsoft Windows® environment. The software control system communicates with hardware components linked to the software through the personal computer serial communications port. The hardware components include telephone communication equipment, digital signal processors, and hardware to enable voice, fax and data communication with a remote site connected through a standard telephone line. The functions of the hardware components are controlled by control software operating within the hardware component and from the software components operating within the personal computer. The major functions of the system are a telephone function, a voice mail function, a fax manager function, a multimedia mail function, a show and tell function, a terminal function and an address book function. The telephone function allows the present system to operate, from the users perspective, as a conventional telephone using either hands-free, headset or handset operation. The telephone function is more sophisticated than a standard telephone in that the present system converts the voice into a digital signal which can be processed with echo cancellation, compressed, stored as digital data for later retrieval and transmitted as digital voice data concurrent with the transfer of digital information data.

Claims

1. A system for full-duplex transmission of voice and data information for use with a personal computer, comprising:

data interface means connected for transferring data to and from the personal computer;

telephone line interface means for connection to a telephone line;

voice interface means for receiving local voice signals from a local user and for conveying remote voice signals from a remote user to the local user;

full-duplex conversion means connected to the voice interface means for converting the local voice signals into outgoing digital voice data and for converting incoming digital voice data into the remote voice signals;

digital signal processor means connected to the full-duplex conversion means the data interface means and the telephone interface means for compressing the outgoing digital voice data into compressed outgoing digital voice data packets and for decompressing compressed incoming digital voice data packets into the incoming digital voice data;

quiet detection means for detecting quiet periods in which the local voice signals are below a predetermined threshold and for producing therefrom a quiet signal;

main control means connected for receiving the compressed outgoing digital voice data from the digital signal processor means, connected for receiving outgoing computer digital data from the personal computer through the data interface means, and for multiplexing and transmitting compressed outgoing digital voice data and outgoing computer digital data when the quiet signal indicates the presence of the local voice signals and for transmitting only outgoing computer digital data when the quiet signal indicates the absence of the local voice signals; and

the main control means further operable for receiving multiplexed incoming data which contains incoming computer digital data multiplexed with the compressed incoming digital voice data, for demultiplexing the incoming computer digital data and the compressed incoming digital voice data, and for sending the incoming computer digital data to the personal computer through the data interface means and for sending the compressed incoming digital voice data to the digital signal processor means.

2. The system according to claim 1 wherein the main control means is further operable for detecting corrupted incoming computer digital data and for requesting retransmission in response thereto and wherein the main control means is further operable for detecting corrupted compressed incoming digital voice data and for ignoring the corruption to preserve real-time operation of voice transmission.

3. The system according to claim 1 wherein the quiet detection means includes:

means for determining a power of the outgoing digital voice data packet including a plurality of samples of the voice signals as a function of a summation of the square of each sample over the outgoing digital voice data packet; and

means for comparing said power of the outgoing digital voice data packet to a preselected threshold to determine whether the outgoing digital voice data packet is a silent outgoing digital voice data packet such that the quiet signal is produced.

4. A method for full duplex transmission of voice and data information for use with a personal computer, comprising the steps of:

transferring computer digital data packets to and from the personal computer;

receiving local voice signals from a local user and conveying remote voice signals from a remote user to the local user;

converting the local voice signals into outgoing digital voice data and converting incoming digital voice data into the remote voice signals;

compressing the outgoing digital voice data into compressed outgoing digital voice data packets and decompressing compressed incoming digital voice data packets into the incoming digital voice data;

detecting quiet periods in which below threshold local voice signals are received and producing therefrom a quiet signal;

multiplexing and transmitting the compressed outgoing digital voice data packets and outgoing computer digital data packets when the quiet signal indicates a presence of local voice signals;

transmitting only computer digital data packets when the quiet signal indicates an absence of local voice signals;

receiving multiplexed incoming data which contains incoming computer digital data packets multiplexed with the compressed incoming digital voice data packets; and

demultiplexing the incoming computer digital data packets and the compressed incoming digital voice data packets and sending the incoming computer digital data packets to the personal computer and decompressing the compressed incoming digital voice data.

5. The method according to claim 4 wherein the method further includes the steps of:

detecting corrupted incoming computer digital data packets and requesting retransmission in response thereto; and

detecting corrupted compressed incoming digital voice data packets and ignoring such corruption to preserve real time operation of voice transmission.

6. A method according to claim 4 wherein said detecting quiet periods step includes the steps of:

determining a power of a at least a portion of the compressed outgoing digital voice data packet including a plurality of samples of the local voice signals as a function of the summation of the square of each sample over the portion of the compressed outgoing digital voice data packet; and

comparing the power of the portion of the compressed outgoing digital voice data packets to a preselected threshold to indicate whether the compressed outgoing digital voice data packet is a silent compressed outgoing digital voice data packet.

7. The method according to claim 6 wherein the multiplexing and transmitting of the compressed outgoing digital voice data packets and outgoing computer digital data packets when the quiet signal indicates the presence of local voice signals, includes the steps of:

collecting and buffering outgoing computer digital data packets;

collecting compressed outgoing digital voice data including non-silent compressed outgoing digital voice data packets and silent compressed outgoing digital voice data packets;

buffering non-silent compressed outgoing digital voice data packets;

discarding silent compressed outgoing digital voice data packets; and

transmitting non-silent compressed outgoing digital voice data packets on a priority basis with respect to outgoing computer digital data packets to ensure integrity of real time voice transmission by monitoring the buffering of the non-silent outgoing compressed digital voice data packets.