Computer-based multifunction personal communications system

• US 5,471,470 A
• Filed: 08/11/1994
• Issued: 11/28/1995
• 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, Young, Steve, Sharma, Raghu, Gunn, Timothy D., Maitra, Sidhartha, Thanawala, Ashish
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): Nguyen, Chau T.
• Application Number:
  US08/289,294
• Time in Patent Office: 474 Days
• Field of Search: 370/24, 370/31, 370/32.1, 370/79, 370/94.2, 370/80, 370/81, 370/110.1, 370/111, 370/112, 370/118, 379/89, 379/207, 379/88, 379/93, 379/96, 379/67, 379/235
• US Class Current: 370/271
• 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 multi-media 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 communication module for use with a personal computer, comprising:

communications interface means connected for communicating to the personal computer for transferring data between the personal computer and the communications module;

telephone line interface means for connection to a telephone line and for full duplex digital communication over the 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 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, each of the compressed outgoing digital voice data packets having headers and each of the compressed incoming digital voice data packets having headers;

main control means connected to the telephone line interface means, connected for receiving the compressed outgoing digital voice data packets from the digital signal processor means, connected for receiving outgoing computer digital data packets from the personal computer through the communications interface means, operable for multiplexing the compressed outgoing digital voice data packets and the computer digital data packets to produce multiplexed outgoing data and for sending the multiplexed outgoing data to the telephone line interface means for transmission over the telephone line; and

the main control means further operable for receiving multiplexed incoming data from the telephone line interface means, the multiplexed incoming data containing incoming computer digital data packets multiplexed with the compressed incoming digital voice data packets, the main control means further operable for demultiplexing the incoming computer digital data packets and the compressed incoming digital voice data packets, and for sending the incoming computer digital data packets to the personal computer through the communications interface means and for sending the compressed incoming digital voice data packets to the digital signal processor means.

2. The module according to claim 1 wherein the digital signal processor means further includes acoustic echo cancellation means for removing at least a portion of the incoming digital voice data from the outgoing digital voice data for acoustic echo cancellation.

3. The module according to claim 1 wherein the digital signal processor means further includes line echo cancellation means for removing at least a portion of the outgoing digital voice data from the incoming digital voice data for line echo cancellation.

4. The module according to claim 1 wherein the digital signal processor means is further operable for receiving the outgoing digital voice data from the full-duplex conversion means, for receiving incoming voice signals from the telephone line, for digitizing the incoming voice signals to produce the incoming digital voice data, for removing at least a portion of the outgoing digital voice data from the incoming digital voice data for line echo cancellation, for converting the outgoing digital voice data back into analog voice signals for transmission in an analog fashion over the telephone line.

5. The module according to claim 4 further including a microphone and a speaker connected to the voice interface means and wherein the digital signal processor means further includes acoustic path echo cancellation means for removing at least a portion of the outgoing digital voice data from the incoming digital voice data for acoustic path echo cancellation.

6. The module according to claim 4 further including digital gain means included in the digital signal processor for providing user-selectable gain or automatic gain control to the incoming digital voice data.

7. The module according to claim 1 wherein the digital signal processor metres is further operable for compressing the outgoing digital voice data into compressed outgoing digital voice data packets by performing the steps of:

a.) removing any DC bias in the outgoing digital voice data to produce a normalized outgoing digital voice signal;

b.) pre-emphasizing the normalized outgoing digital voice signal to produce a preemphasized outgoing digital voice signal;

c.) dividing the pre-emphasized outgoing digital voice signal into segments to produce a current segment and a past segment;

d.) predicting the pitch of the current speech segment to form a pitch prediction;

c.) calculating the gain of the pitch of the current speech segment to form a prediction gain;

e.) reconstructing the past speech segment from a compressed past segment to produce a reconstructed past segment;

f.) finding the innovation in the current speech segment by comparing the pitch prediction to the reconstructed past segment to produce an error signal;

g.) determining the maximan amplitude in the current speech segment;

h.) quantizing the error signal using a code book generated from a representative set of speakers and environments to produce a minimum member squared error matching the form of an index into the code book; and

i.) recording the pitch prediction, the prediction gain, the maximum amplitude and the index into the code book in a packet as the compressed outgoing digital voice data.

8. The module according to claim 1 wherein the digital signal processor means is further operable for detecting silent periods in the outgoing digital voice data and for producing in response thereto a silence flag and wherein the main control means is further operable for transmitting outgoing computer digital data packets on the telephone line when the silence flag indicates the absence of voice information and wherein the main control means is further operable for multiplexing, modulating and transmitting both the compressed outgoing digital voice data packets and the outgoing computer digital data action the telephone line when the silence flag indicates the presence of voice information.

9. The module according to claim 1 wherein the telephone line includes a cellular telephone link and wherein the main control means is further operable for periodically transmitting a cellular supervisory packet on the telephone line and for maintaining the link to the remote site over the telephone line if the remote site acknowledges receipt of the cellular supervisory packet within a predetermined period of time and for dropping the link to the remote site over the telephone line if the remote site fails to acknowledges receipt of the cellular supervisory packet within a predetermined period of time.

10. The module according to claim 1 wherein the main control means is further operable for receiving fax data from the personal computer through the communications interface means and for transmitting the fax data over the telephone line.

11. The system according to claim 1 wherein the telephone line is an analog telephone line and the telephone line interface memos is further operable for modulating the multiplexed outgoing digital data into a modulated analog signal for full duplex digital communication.

12. The system according to claim 1 wherein the telephone line is a digital telephone line and the telephone line interface means is further operable for sending the multiplexed outgoing digital data over the telephone line as unmodulated digital data for full duplex digital communication.