United States Patent r19i
`Sharma et al.
`
`I lllll llllllll Ill lllll lllll lllll lllll lllll 111111111111111111111111111111111
`US005546395A
`[11] Patent Number:
`[45] Date of Patent:
`
`5,546,395
`Aug. 13, 1996
`
`[54] DYNAMIC SELECTION OF COMPRESSION
`RATE FOR A VOICE COMPRESSION
`ALGORITHM IN A VOICE OVER DATA
`MODEM
`
`[75]
`
`Inventors: Raghu N. Sharma, North Oaks;
`Jeffrey P. Davis, Ham Lake; Timothy
`D. Gunn, Mounds View; Ping Li, New
`Brighton, all of Minn.; Sidhartha
`Maitra; Ashish A. Thanawala, both of
`Saratoga, Calif.
`
`[73] Assignee: Multi-Tech Systems, Inc., Mounds
`View, Minn.
`
`[21] Appl. No.: 346,421
`
`[22] Filed:
`
`Nov. 29, 1994
`
`Related U.S. Application Data
`
`[63] Continuation-in-part of Ser. No. 271,496, Jul. 7, 1994, and
`a continuation-in-part of Ser. No. 2,467, Jan. 8, 1993, Pat.
`No. 5,452,289.
`Int. Cl.6
`•••.•••••.•.•..••.•••...•.•••••••• H04J 3/22; GlOL 5/00
`[51]
`[52] U.S. Cl •............................ 370/84; 370/118; 3701112;
`375/246; 395/2.28
`[58] Field of Search ................................ 370/94.1, 110.1,
`370/118, 112, 79, 76, 82, 84, 24; 395/2,
`2.2, 2.21, 2.28, 2.3, 2.31; 381/29, 32, 36,
`30, 41; 375/245, 246; 455/72; 341/51
`
`[56]
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`Re. 34,034
`3,304,372
`3,789,165
`3,904,830
`3,973,081
`3,997,732
`4,100,377
`4,107,471
`
`8/1992 O'Sullivan ................................ 379/59
`2/1967 Filipowsky et al ..
`1/1974 Campanella et al. ................... 179/170
`911975 Every, Sr. et al ..
`8/1976 Hutchins ................................ 395/2.28
`12/1976 Every, Sr. et al. ........................ 179/18
`711978 Flanagan ................................... 179115
`8/1978 Reed ......................................... 179/15
`
`FOREIGN PATENT DOCUMENTS
`
`488865A2
`63-054052
`2210237
`
`6/1992 European Pat. Off ..
`8/1988
`Japan .
`1/1989 United Kingdom .
`
`OTHER PUBLICATIONS
`
`European Search Report for Application No. EP 93403164
`completed on Sep. 21, 1995 by Examiner Lambley; 4 pages.
`S. Casale et al., "Statistical Voice/High-Speed Data Multi(cid:173)
`plexing on a 64 KBIT/S Channel," IEEE, pp. 459-464,
`dated 1991.
`T. Komiya et al, "An Approach to the Multifunction Graphic
`Terminal for the ISDN Environment", IEEE, pp. 32-36,
`dated 1988.
`
`(List continued on next page.)
`
`Primary Examiner-Wellington Chin
`Assistant Examiner-Chau T. Nguyen
`Attorney, Agent, or Firm-Schwegman, Lundberg, Woess(cid:173)
`ner & Kluth, P.A.
`
`[57]
`
`ABSTRACT
`
`The present invention includes software and hardware com(cid:173)
`ponents to enable digital data communication over standard
`telephone lines. The present invention converts analog voice
`signals to digital data, compresses that data and places the
`compressed speech data into packets for transfer over the
`telephone lines to a remote site. A voice control digital signal
`processor (DSP) operates to use one of a plurality of speech
`compression algorithms which produce a scaleable amount
`of compression. The rate of compression is inversely pro(cid:173)
`portional to the quality of the speech the compression
`algorithm is able to reproduce. The higher the compression,
`the lower the reproduction quality. The selection of the rate
`of compression is dependent on such factors as the speed or
`data bandwidth on the communications connection between
`the two sites, the data demand between the sites and amount
`of silence detected in the speech signal. The voice compres(cid:173)
`sion rate is dynamically changed as the aforementioned
`factors change. A negotiation handshake protocol
`is
`described which enables the two sites to negotiate the
`compression rate based on such factors.
`
`(List continued on next page.)
`
`4 Claims, 7 Drawing Sheets
`
`BK
`
`1252
`
`1241
`K
`1251
`~B""--rSA-MP:--L-E -RA~J--,E
`6.4K
`BK
`DECIMATOR
`
`6K
`
`125D
`
`1211
`
`GAIN
`CODE
`
`1203
`
`1207
`
`1209
`
`REMOVE
`D.C.
`
`PRE(cid:173)
`EMPHASIS
`
`LTP
`PITCH/GAIN
`
`1215
`
`16K BK 9.6K
`'-------v----'
`CODE BOOKS
`
`1219
`
`INVERSE
`LTP
`
`1221
`
`1242
`
`SAMPLE
`RATE
`INCREMENTOR
`
`)
`16K
`PCM
`9.6K DATA
`OUT
`
`BK
`
`IPR2016-01710
`UNIFIED EX1008
`
`

`
`5,546,395
`Page 2
`
`U.S. PATENT DOCUMENTS
`
`4,205,202
`4,284,850
`4,354,273
`4,377,860
`4,403,322
`4,425,661
`4,445,213
`4,476,559
`4,479,195
`4,479,213
`4,495,620
`4,500,987
`4,524,244
`4,534,024
`4,546,212
`4,578,537
`4,587,651
`4,593,389
`4,609,788
`4,629,829
`4,652,703
`4,660,218
`4,670,874
`4,697,281
`4,700,341
`4,707,831
`4,718,082
`4,740,963
`4,750,169
`4,751,510
`4,751,736
`4,757,527
`4,764,955
`4,807,250
`4,809,271
`4,813,040
`4,827,085
`4,835,765
`4,839,802
`4,845,746
`4,847,900
`4,862,449
`4,866,732
`4,887,265
`4,890,282
`4,901,333
`4,905,282
`4,912,758
`4,914,650
`4,926,448
`4,932,048
`4,935,954
`4,942,569
`4,953,210
`4,965,789
`4,972,457
`4,972,462
`4,972,483
`4,977,591
`4,991,169
`4,995,059
`4,998,241
`5,001,710
`5,001,745
`5,005,183
`5,008,926
`5,014,232
`5,020,058
`5,036,513
`5,044,010
`
`5/1980 Kahn ......................................... 370/81
`8/1981 Clingenpeel .............................. 370/81
`10/1982 Araseki et al. . ........................ 375/245
`311983 Godbole .................................... 370/84
`911983 Kato et al ............................... 370/110
`111984 Moses et al. ............................... 37511
`4/1984 Baugh et al .............................. 370/94
`10/1984 Brolin et al ............................. 370/110
`10/1984 Herr et al. . ............................. 364/900
`1011984 Galand et al ........................... 3701118
`111985 Steele et al ............................. 3701118
`2/1985 Hasegawa ................................. 370/60
`6/1985 Faggin et al ..
`8/1985 Maxemchuk et al. .................... 370/85
`10/1985 Crowder, Sr ................................ 17912
`3/1986 Faggin et al. ............................... 179/2
`5/1986 Nelson et al.
`. ........................... 370/88
`6/1986 Wurzburg et al ....................... 370/110
`9/1986 Miller et al. ......................... 179/170.6
`1211986 Puhl et al. . ............................... 379/58
`3/1987 Lu et al .................................. 379/339
`411987 Hashimoto ................................ 379/93
`6/1987 Sato et al ............................. 370/H0.1
`9/1987 O'Sullivan ................................ 379/59
`10/1987 Huang ....................................... 370/80
`11/1987 Weir et al. . ............................... 370/94
`1/1988 Parker et al. . ............................ 379/98
`411988 Eckley ................................. 370/110.1
`6/1988 Carse et al .............................. 370/109
`6/1988 De Saint Michel et al. ...... 340/825.07
`611988 Gupta et al. ........................... 395/2.21
`7/1988 Beniston et al ......................... 379/410
`8/1988 Galand et al ........................... 379/411
`211989 Tanaka .................................... 375/245
`2/1989 Kondo et al ......................... 370/110.l
`311989 Futato ..................................... 370/111
`511989 Yaniv et al ............................... 178118
`511989 Bergmans et al ......................... 370/32
`6/1989 Wonak et al ........................... 364/200
`7/1989 Li ............................................ 379/411
`7/1989 Wakim .................................... 379/424
`8/1989 Hoetkens et al. . ....................... 370/32
`9/1989 Carey et al. ................................ 375/1
`1211989 Felix ...................................... 370/94.1
`12/1989 Lambert et al. . ......................... 370179
`211990 Hodgkiss .................................. 375/98
`2/1990 McG!ynn et al. . ....................... 380/48
`3/1990 Arbel ...................................... 379/388
`4/1990 Sriram ....................................... 370/60
`5/1990 Kraul et al. ............................. 3751121
`611990 Kenmochi et al. . ...................... 379/67
`6/1990 Thompson et al ........................ 379/89
`711990 Maeno ...................................... 370/60
`8/1990 McG!ynn et al ......................... 380/48
`10/1990 Bottau et al .............................. 370179
`11/1990 O'Sullivan ................................ 379/59
`1111990 Shibata ...................................... 379/89
`1111990 Carey ..................................... 395/2.21
`1211990 Chen et al. ............................. 379/410
`211991 Davis et al ............................... 370177
`2/1991 Ishikawa ................................... 375/27
`3/1991 Brox et al .............................. 370/32.1
`3/1991 Gawrys et al ....................... 370/110.1
`3/1991 Pollock ..................................... 379/96
`411991 Carey et al ................................. 37511
`4/1991 Misholi ..................................... 379/89
`511991 Andre ................. , .................... 3641724
`5/1991 Holden et al ........................... 370/109
`7/1991 Greenblatt ............................... 370/125
`8/1991 Frenkiel et al ........................... 379/61
`
`5,046,188
`5,051,720
`5,062,133
`5,065,425
`5,081,647
`5,083,310
`5,086,471
`5,099,472
`5,107,519
`5,115,429
`5,121,385
`5,127,001
`5,127,041
`5,132,966
`5,136,586
`5,138,662
`5,146,470
`5,150,410
`5,151,937
`5,153,897
`5,162,812
`5,177,734
`5,182,762
`5,187,591
`5,187,692
`5,193,110
`5,195,130
`5,208,812
`5,208,850
`5,214,656
`5,228,026
`5,233,660
`5,235,595
`5,249,218
`5,258,983
`5,261,027
`5,263,019
`5,272,695
`5,276,703
`5,278,900
`5,282,197
`5,283,638
`5,283,819
`5,289,539
`5,295,136
`5,305,312
`5,307,413
`5,309,562
`5,313,498
`5,317,604
`5,319,682
`5,327,520
`5,329,472
`5,341,374
`5,343,473
`5,343,521
`5,371,853
`5,406,560
`5,414,796
`
`9/1991 Molnar ...................................... 379/94
`9/1991 Kittirutsunetorn ...................... 340/310
`10/1991 Melrose .................................... 379/94
`1111991 Lecomte et al ........................... 379/93
`111992 Bremer ........................................ 375/5
`111992 Drory ..................................... 395/2.21
`211992 Tanaka et al ............................. 381136
`3/1992 Townsend et al ..................... 370/32.1
`411992 Ishikawa ................................... 375/27
`511992 Hluchyj et al ......................... 370/94.1
`611992 Tominaga et al ......................... 370/80
`6/1992 Steagall et al. ........................... 370/62
`611992 O'Sullivan ................................ 379/59
`711992 Hayano et al ............................ 370179
`811992 Greenblatt ............................... 370/110
`8/1992 Amano et al. ......................... 395/2.28
`911992 Fujii et al ............................... 3751103
`9/1992 Bertrand .................................... 380/28
`9/1992 Chujo et al ............................. 379/410
`10/1992 Sumiyoshi et al. ......................... 375/8
`1111992 Aman et al. .............................. 375/34
`111993 Cummiskey et al. .................... 370/32
`1/1993 Shirai et al. . ........................... 375/122
`2/1993 Guy et al ................................ 358/425
`211993 Haneda et al ........................... 3671135
`311993 Jones et al ................................ 379/94
`311993 Weiss et al. . ............................. 379/90
`511993 Dudek et al ......................... 3701100.1
`511993 Kino .......................................... 379/88
`511993 Chung et al .............................. 371/43
`7/1993 Albrow et al ............................. 370/29
`8/1993 Chen ......................................... 381138
`8/1993 O'Dowd ................................. 370/94.1
`9/1993 Sainton ..................................... 379/59
`1111993 Lane et al. .............................. 370/118
`1111993 Taniguchi et al. .......................... 395/2
`1111993 Chu ........................................... 370/32
`1211993 Makino et al ......................... 370/32.1
`111994 Budin et al. ................................ 375/1
`111994 Van Gerwen et al .................. 379/410
`111994 Kreitzer .................................... 370176
`2/1994 Engberg et al ........................... 348114
`2/1994 Glick et al ................................ 379/90
`211994 Maruyama .............................. 379/410
`311994 Ashley et al. ............................ 370/32
`411994 Fornek et al.
`............................ 370/62
`4/1994 Denzer ...................................... 380/49
`5/1994 Li .
`511994 Sano ........................................ 375/103
`511994 Osterweil ................................ 375/122
`611994 Clark ....................................... 375/122
`711994 Chen ........................................... 395/2
`7/1994 Sugiyama ................................ 364/724
`8/1994 Lewen et al. .......................... 370/85.4
`8/1994 Cidon et al ............................ 370/85.6
`8/1994 Jullien et al ............................ 379/410
`1211994 Kao et al. . ............................. 395/2.32
`411995 Kondo et al ............................ 375/245
`511995 Jacobs ...................................... 395/2.3
`
`OTHER PUBLICATIONS
`
`D. Gulick et al., "Interface for the ISDN to Your PC with A
`Voice/Data Board", Electronic Design, pp. 85-88, dated
`Dec. 10, 1987.
`S. Sasaki et al., "Variable Rate Voice Coding System", IEEE,
`pp. 364-367, dated 1992.
`AT&T Microelectronics, "High Speed Data Pump Chip
`Sets'', published in Dec. 1991.
`AT&T Microelectronics, "WE DSP16C Digital Signal Pro(cid:173)
`cessor/CODEC Preliminary Data Sheet", 32 pages, May
`published in 1991.
`
`

`
`5,546,395
`Page 3
`
`AT&T Microelectronics, ''T7540 Digital Telephone CODEC
`Data Sheet Addendum", pp. 1-4, published in Jul., 1991.
`AT&T Microelectronics, "T7540 Digital Telephone CODEC
`Preliminary Data Sheet", pp. 1-64, published in Jan., 1991.
`Zilog Intelligent Peripheral Controllers, "Z84C01 Z80 CPU
`with Clock Generator/Controller," pp. 43-73, published in
`1991.
`Zilog Intelligent Peripheral Controllers, "Z84C90 CMOS
`Z80 KIO Serial/Parallel/counter/timer," pp. 205-224, pub(cid:173)
`lished in 1991.
`U.S. West Caller ID publication, received Jul. 18, 1994, one
`page.
`J. D. Mills, et al., "A Data and Boice System for the General
`Service Telephone Network," /ECON, pp. 1143-1148, 1987.
`Copy of European Search Report (Application No. EP
`94304742), completed Jun. 8, 1995 by Examiner Mikkelsen.
`
`"TechTips-A Periodic Round-up of Technical Applica(cid:173)
`tions, Notes, and Information on MultiTech's Data Com(cid:173)
`munications Products" by MultiTech Systems, vol. 2, No. 2,
`May 1992.
`
`"MultiX25-X.25 PAD, The New MultiX25 PAD 8 Port
`X.25 Packet Assembler/Disassembler for Public and Private
`Data Networks," by MultiTech Systems. Mar. 1992 (2
`pages).
`
`Y. Akaiwa et al., "An Integrated Voice and Data Radio
`Access System," 1992, pp. 255-258, IEEE.
`
`CCITT V.42, "Error-Correcting Procedures for DCES
`Using Asynchronous-to-Synchronous Conversion", vol.
`vm, pp. 296--370, dated 1988.
`
`

`
`U.S. Patent
`
`Aug. 13, 1996
`
`Sheet 1of7
`
`5,546,395
`
`0
`0 ..-
`
`0
`OJ
`
`0
`0
`N
`
`'
`
`en
`0
`
`o
`r')\
`~
`
`

`
`Ul
`\,C
`~
`~ ...
`.a;;..
`Ul
`...
`Ul
`
`'1
`s,
`N
`m.
`\l'l =-
`
`'-= =-.
`'-=
`""""
`"""" "~
`~
`~
`
`~ = ~ = "'"""
`
`•
`00
`•
`cj
`
`______ J
`I
`I
`I
`I
`1
`1
`I
`I
`I
`I
`I
`I
`r-----,
`-_I
`I_ -
`I
`I
`I
`I
`
`~I
`
`-
`
`-
`
`317-
`
`I
`
`PEPROM
`
`-----,
`
`l -
`1 SERIAL INTERFACE
`
`-
`
`-
`
`..,,1
`
`RS232
`
`,_ __
`I
`
`314
`/
`
`,-----
`
`_r--r--,
`
`I
`
`I
`
`I
`
`l __ _! ___ I
`
`I
`I
`316
`
`' 'f ::_ ::_I-sro-{ cTc-C ~
`-t -----I
`I
`
`CONTROLLER
`
`MAIN
`
`----
`
`,_ ______ _
`
`-
`
`I DATA PUMP
`
`DSP
`
`I
`I
`
`I
`I
`I
`
`\
`.
`312
`
`-311
`
`/
`
`,,.
`310
`
`.J
`I
`
`/
`
`-
`
`-
`
`L ___ :J
`
`-
`
`.,,
`
`_
`
`-
`
`_
`
`-
`
`-
`
`-
`
`-
`
`-
`
`,---------
`
`LINE INTERFACE
`
`TELEPHONE
`
`L -
`,.. -1
`1
`
`309
`
`/ /
`
`315
`
`I
`
`RAM
`DSP'S ...
`
`FIG. 2
`
`307
`
`r --~ --,
`
`I
`RAM
`I
`I
`1 1 PORT
`DUAL
`I
`
`I
`
`1
`I
`
`308
`
`~~~=--=:.:....:.=.--r--t, __ ..;;:o...,sr-P __ .....
`CONTROL LINES I
`
`VOICE CONTROL
`
`I
`
`I
`-----;
`
`CODEC
`
`SERIAL VO 1
`I
`I
`r-----
`
`306
`
`I
`I
`
`I
`I-/
`I
`i 305
`
`I
`
`-
`
`TELEPHONE
`
`DIGITAL
`
`r-(cid:173)
`
`, -
`
`CODEC
`
`HANDSET
`
`HEADSET
`
`302
`
`301
`
`303
`
`.304
`
`MICROPHONE SPEAKER
`
`

`
`01
`~
`~
`~ -..
`.&;.
`01
`-..
`01
`
`i ('!) -~
`
`~
`""t:I
`0
`
`rJ'J.
`
`\C =-.
`\C
`"'~ ....
`~ ....
`~
`
`~ a
`Pl
`""C
`•
`00
`e •
`
`SPEECH
`
`'--------------
`I
`l
`I
`I
`I
`I
`I
`OUT
`~SYNTHESIS 1---l DE-EMPHA.51S ~
`
`/
`
`1200
`
`-_/_ -
`
`/
`
`111.3 __ _L_1_1 ~5 :
`I
`I
`I
`...,
`
`RECEIVER
`
`-
`
`-
`
`-
`
`-
`
`-
`
`-
`
`-
`
`-
`
`:
`I
`I
`I
`I -
`
`FIG. 3
`
`I SYNTHESIS I '
`
`I ______________________ I
`I
`I
`
`1107
`
`CHANNEL
`
`~ 1111
`
`I
`I
`1105 I
`I
`I
`I
`I
`r-----------------L---1
`
`1109
`
`1103
`
`1101
`
`/
`
`1100
`
`/
`
`TRANSMllTER
`
`BOOK
`CODE
`
`PRE-EMPHASIS +
`
`SPEECH -H DC
`
`I REMOVAL
`
`IN
`
`

`
`U.S. Patent
`
`Aug. 13, 1996
`
`Sheet 4 of 7
`
`5,546,395
`
`1201
`
`1203
`
`1205
`
`1207
`
`1209
`
`1211
`
`1213
`
`1215
`
`1217
`
`1219
`
`1221
`
`Sf ART ANALYSIS
`
`DC REMOVAL
`
`SILENCE DETECTION
`
`PREEMPHASIS
`
`COMPUTE PITCH
`
`COMPUTE THE
`LTP GAIN
`
`LTP FILTER
`
`CODE BOOK SEARCH
`& QUANTIZATION
`
`CODE GAIN
`OF BLOCK
`
`INV. LTP FILTER
`
`DEEMPHASIS
`
`NO
`
`EXIT
`
`1225
`
`FIG. 4
`
`

`
`U.S. Patent
`
`Aug. 13, 1996
`
`Sheet 5 of 7
`
`5,546,395
`
`SYNTHESIS
`
`1301
`
`DECODE
`PITCH
`
`DECODE LTP GAIN
`
`DECODE CODE
`BOOK ENTRIES
`
`INV. LTP FILTER
`
`DEEMPHASIS
`
`1303
`
`1305
`
`1307
`
`1309
`
`1311
`
`NO
`
`EXIT
`
`1315
`
`FIG. 5
`
`

`
`~ --~
`.a;;;...
`--01
`01
`
`01
`\C
`
`""1
`~
`~
`~
`tl.l =(cid:173) n:i
`
`~ ,...
`$ ,...
`
`~
`\C
`\C
`
`~ = """"
`
`~
`•
`rJ1
`0 •
`
`... BK
`OUT
`... 9.6K ? DATA
`PCM
`... 1 6K
`
`,
`
`'
`
`INCREMENTOR I
`
`RATE
`
`1
`
`I
`DE-EMPHASIS
`
`SAMPLE
`s
`1242 I
`
`s
`1221
`
`LTP
`
`INVERSE
`
`CHANNEL
`
`/
`
`1219
`
`FIG. 6
`
`CODE BOOKS
`
`16K BK 9.6K
`
`ALGORITHM
`
`VQ
`
`1215
`
`s
`1211
`
`CODE
`GAIN
`
`1250
`
`6K
`
`)
`
`PITCH/GAIN
`
`LTP
`
`EMPHASIS
`
`PRE(cid:173)
`
`REMOVE
`
`D.C.
`
`s
`1209
`
`1207
`
`)
`
`1203
`
`)
`
`.. , SAMPLE RATE I ) 6.4K
`
`I DECIMATOR
`
`1251
`
`1241
`
`)
`
`s
`1252
`
`BK
`
`BK
`
`BK
`
`

`
`="'- "' w
`~
`"' ~
`~
`
`~
`\C
`
`"'-l
`s,
`"'-l
`~
`~
`00. ::r
`
`~
`
`="
`\C
`\C
`~
`"'w
`~
`
`~ = """"
`~ • en •
`
`~
`
`FIG. 7
`
`309
`/
`
`-
`
`311
`7
`
`J\CE
`
`LINE INTERF
`
`DATA PUMP
`
`L---------
`: TRANSMITIER
`I
`I
`I -
`I
`I
`
`I
`
`I../
`1519
`
`RECEIVER
`
`I
`I
`I
`I
`I
`I
`L./
`I
`15171
`I
`I
`r--------1-
`/
`,
`1515
`
`-
`
`CONTROL
`MULTIPLEX
`
`LEVEL
`
`.
`
`I
`I
`I
`I
`I
`I
`I
`
`I
`
`I
`I
`I
`
`I
`
`BUFFER
`V-DATA
`
`RECEIVER
`
`BUFFER~
`C-DATA
`
`BUFFER
`V-DATA
`
`/
`
`,
`1505
`
`I
`I
`I
`I
`I
`I
`r ---
`I
`VOICE DSP I
`
`DATA SERVICE LEVEL
`L---------
`I
`: TRANSMITTER
`I
`15131
`BUFFER "
`I
`C-DATA
`I
`I
`I
`I
`I
`L/
`1511 :
`I
`:
`15091
`I
`I
`I
`I
`I
`I
`L./
`15071
`I
`,_ ___ _J_
`
`.
`
`I
`I
`I
`I
`I
`I
`I
`I
`I
`I
`I
`I
`
`I
`
`DT E INTERFACE
`
`306
`
`

`
`5,546,395
`
`1
`DYNAMIC SELECTION OF COMPRESSION
`RATE FOR A VOICE COMPRESSION
`ALGORITHM IN A VOICE OVER DATA
`MODEM
`
`This patent application is a Continuation-In-Part of U.S.
`patent application Ser. No. 08/271,496 filed Jul. 7, 1994
`entitled "VOICE OVER DATA MODEM WITH SELECT(cid:173)
`ABLE VOICE COMPRESSION", the complete application
`of which is hereby incorporated by reference, and also U.S.
`patent application Ser. No. 08/002,467 filed Jan. 8, 1993,
`now issued as U.S. Pat. No. 5,452,289 on Sep. 19, 1995
`entitled "COMPUTER-BASED MULTIFUNCTION PER(cid:173)
`SONAL COMMUNICATIONS SYSTEM", the complete
`application of which, including the microfiche appendix, is
`also hereby incorporated by reference.
`A microfiche appendix is included in the application, 1
`microfiche and 92 pages.
`
`FIELD OF THE INVENTION
`
`The present invention relates to communications systems
`and in particular to modem communications having simul(cid:173)
`taneous digitized voice and data capabilities.
`
`BACKGROUND OF THE INVENTION
`
`5
`
`2
`cally allocates data bandwidth over the telephone line
`depending on the demands of the voice grade digitized
`signal and the modulation speed of the communication link
`between the two sites.
`The present invention includes software and hardware
`components to enable digital data communication over
`standard telephone lines. The present invention converts
`analog voice signals to digital data, compresses that data and
`places the compressed speech data into packets for transfer
`10 over the telephone lines to a remote site. A voice control
`digital signal processor (DSP) operates to use one of a
`plurality of speech compression algorithms which produce a
`scaleable amount of compression. The rate of compression
`is inversely proportional to the quality of the speech the
`15 compression algorithm is able to reproduce. The higher the
`compression, the lower the reproduction quality. The selec(cid:173)
`tion of the rate of compression is dependant on such factors
`as the speed or data bandwidth on the communications
`connection between the two sites, the data demand between
`the sites and amount of silence detected in the speech signal.
`The voice compression rate is dynamically changed as the
`aforementioned factors change. A negotiation handshake
`protocol is described which enables the two sites to nego(cid:173)
`tiate the compression rate based on such factors.
`
`20
`
`25
`
`DESCRIPTION OF THE DRAWINGS
`
`In the drawings, where like numerals describe like com(cid:173)
`ponents throughout the several views,
`FIG. 1 shows the telecommunications environment within
`which the present may operate in several of the possible
`modes of communication;
`FIG. 2 is a block diagram of the hardware components of
`the present system;
`FIG. 3 is a detailed function flow diagram of the speech
`compression algorithm;
`FIG. 4 is a detailed function flow diagram of the speech
`decompression algorithm;
`FIG. 5 is a signal flow diagram of the speech compression
`algorithm;
`FIG. 6 is a signal flow diagram of the speech compression
`algorithm showing details of the code book synthesis; and
`FIG. 7 is a detailed function flow diagram of the voice/
`45 data multiplexing function.
`
`Simultaneous voice and modem data transmitted over the
`same communications link between two sites has been
`accomplished in several ways. The most common commu(cid:173)
`nications link used between two sites is the telephone line. 30
`The most common data handling equipment to communicate
`over a communications link is the computer modem which
`modulates digital data onto a carrier for transmission in the
`voice band of the telephone line. A wide variety of modu(cid:173)
`lation standards have been promulgated by such intema- 35
`tional groups as the CCITT for communication in the voice
`band. The data bandwidth for such modulation standards is
`typically fixed and the throughput rate of data is also
`assumed to be fixed.
`In some modulations standards, there are provisions for 40
`changing the modulation data rate based on the quality of the
`communications link. For example, in a noisy telephone
`line, a 9600 baud modulation rate may have such a high bit
`error rate that the modulation must be changed to a 2400
`baud connection. This is done in a handshake communica(cid:173)
`tion protocol between the two sites when the communica(cid:173)
`tions link simply cannot support the higher rate.
`There is a need in the art, however, for an efficient and
`cost effective way of maximizing bandwidth over the com(cid:173)
`munications link between two sites to enable the simulta- 50
`neous transmission of voice and data. There is a need,
`therefore, to negotiate the data bandwidth between the sites,
`negotiate the compression rate for the voice compression
`algorithms used to compress the voice and there is a need to
`allocate and reallocate the ratio of compress voice to digital
`data transmitted over the communications link.
`
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENTS
`
`55
`
`The specification for the multiple inventions described
`herein includes the present description, the drawings and a
`microfiche appendix. In the following detailed description of
`the preferred embodiment, reference is made to the accom(cid:173)
`panying drawings which form a part hereof, and in which is
`shown by way of illustration specific embodiments in which
`the inventions may be practiced. These embodiments are
`described in sufficient detail to enable those skilled in the art
`to practice the invention, and it is to be understood that other
`embodiments may be utilized and that structural changes
`60 may be made without departing from the spirit and scope of
`the present inventions. The following detailed description is,
`therefore, not to be taken in a limiting sense, and the scope
`of the present inventions is defined by the appended claims.
`FIG. 1 shows a typical arrangement for the use of the
`65 present system. Personal computer 10 is running the soft(cid:173)
`ware components of the present system while the hardware
`components 20 include the data communication equipment
`
`SUMMARY OF THE INVENTION
`
`The present invention solves the aforementioned prob(cid:173)
`lems and shortcoming of the existing art and solves other
`problems not listed above which will become apparent to
`those skilled in the art upon reading and understanding the
`present specification and claims. The present invention
`describes a voice over data modem which allows the opera(cid:173)
`tor to simultaneously transmit voice and data communica(cid:173)
`tion to a remote site. This voice over data function dynarni-
`
`

`
`5,546,395
`
`General Overview
`
`25
`
`3
`4
`the present system. This module also creates queues for
`and telephone headset. Hardware components 20 commu(cid:173)
`outgoing messages to be sent at preselected times and allows
`nicate over a standard telephone line 30 to one of a variety
`the users to create outgoing messages with the voice editor.
`of remote sites. One of the remote sites may be equipped
`with the present system including hardware components 20a
`The fax manager portion of the present system is a queue
`and software components running on personal computer 5
`for incoming and outgoing facsimile pages. In the preferred
`lOa. In one alternative use, the local hardware components
`embodiment of the present system, this function is tied into
`20 may be communicating over standard telephone line 30
`the Windows "print" command once the present system has
`to facsimile machine 60. In another alternative use, the
`been installed. This feature allows the user to create faxes
`present system may be communicating over a standard
`from any Windows®-based document that uses the "print"
`telephone line 30 to another personal computer 80 through IO command. The fax manager function of the present system
`a remote modem 70. In another alternative use, the present
`allows the user to view queued faxes which are to be sent or
`system may be communicating over a standard telephone
`which have been received. This module creates queues for
`line 30 to a standard telephone 90. Those skilled in the art
`outgoing faxes to be sent at preselected times and logs
`will readily recognize the wide variety of communication
`incoming faxes with time/date stamps.
`interconnections possible with the present system by reading 15
`The multi-media mail function of the present system is a
`and understanding the following detailed description.
`utility which allows the user to compose documents that
`The ornamental features of the hardware components 20
`include text, graphics and voice messages using the message
`of FIG. 1 are claimed as part of Design Patent Application
`composer function of the present system, described more
`Number 29/001368, filed Nov. 12, 1992 entitled "Tele(cid:173)
`fully below. The multi-media mail utility of the present
`20 system allows the user to schedule messages for transmittal
`phone/Modem case for a Computer-Based Multifunction
`Personal Communications System" assigned to the same
`and queues up the messages that have been received so that
`assignee of the present inventions and hereby incorporated
`can be viewed at a later time.
`by reference.
`The show and tell function of the present system allows
`the user to establish a data over voice (DOV) communica-
`tions session. When the user is transmitting data to a remote
`location similarly equipped, the user is able to talk to the
`person over the telephone line while concurrently transfer(cid:173)
`ring the data. This voice over data function is accomplished
`in the hardware components of the present system. It digi-
`tizes the voice and transmits it in a dynamically changing
`allocation of voice data and digital data multiplexed in the
`same transmission. The allocation at a given moment is
`selected depending on the amount of voice digital informa-
`tion required to be transferred. Quiet voice intervals allocate
`greater space to the digital data transmission.
`The terminal function of the present system allows the
`user to establish a data communications session with another
`computer which is equipped with a modem but which is not
`40 equipped with the present system. This feature of the present
`system is a WindowsTM_based data communications pro(cid:173)
`gram that reduces the need for issuing "AT" commands by
`providing menu driven and "pop-up" window alternatives.
`The address book function of the present system is a
`45 database that is accessible from all the other functions of the
`present system. This database is created by the user inputting
`destination addresses and telephone numbers for data com(cid:173)
`munication, voice mail, facsimile transmission, modem
`communication and the like. The address book function of
`the present system may be utilized to broadcast communi(cid:173)
`cations to a wide variety of recipients. Multiple linked
`databases have separate address books for different groups
`and different destinations may be created by the users. The
`address book function includes a textual search capability
`55 which allows fast and efficient location of specific addresses
`as described more fully below.
`
`30
`
`35
`
`The present inventions are embodied in a commercial
`product by the assignee, MultiTech Systems, Inc. The soft(cid:173)
`ware component operating on a personal computer is sold
`under the commercial trademark of MultiExpressPCSTM
`personal communications software while the hardware com(cid:173)
`ponent of the present system is sold under the commercial
`name of MultiModemPCSTM, Intelligent Personal Commu(cid:173)
`nications System Modem. In the preferred embodiment, the
`software component runs under Microsoft® WindowsTM
`however those skilled in the art will readily recognize that
`the present system is easily adaptable to run under any single
`or multi-user, single or multi-window operating system.
`The present system is a multifunction communication
`system which includes hardware and software components.
`The system allows the user to connect to remote locations
`equipped with a similar system or with modems, facsimile
`machines or standard telephones over a single analog tele(cid:173)
`phone line. The software component of the present system
`includes a number of modules which are described in more
`detail below.
`The telephone module allows the system to operate as a
`conventional or sophisticated telephone system. The system
`converts voice into a digital signal so that it can be trans(cid:173)
`mitted or stored with other digital data, like computer
`information. The telephone function supports PBX and
`Centrex features such a call waiting, call forwarding, caller
`ID and three-way calling. This module also allows the user
`to mute, hold or record a conversation. The telephone
`module enables the handset, headset or hands-free speaker
`telephone operation of the hardware component. It includes
`on-screen push button dialing, speed-dial of stored numbers
`and digital recording of two-way conversations.
`The voice mail portion of the present system allows this 60
`system to operate as a telephone answering machine by
`storing voice messages as digitized voice files along with a
`time/date voice stamp. The digitized voice files can be saved
`and sent to one or more destinations immediately or at a later
`time using a queue scheduler. The user can also listen to, 65
`forward or edit the voice messages which have been
`received with a powerful digital voice editing component of
`
`50
`
`Hardware Components
`
`FIG. 2 is a block diagram of the hardware components of
`the present system corresponding to reference number 20 of
`FIG. 1. These components form the link between the user,
`the personal computer running the software component of
`the present system and the telephone line interface. As will
`be more fully described below, the interface to the hardware
`components of the present system is via a serial communi(cid:173)
`cations port connected to the personal computer. The inter-
`
`

`
`5,546,395
`
`6
`serial interface circ