U.S. patent application number 09/982564 was filed with the patent office on 2002-04-18 for apparatus and method for multi-station conferencing.
This patent application is currently assigned to VocalTec Communications Ltd.. Invention is credited to Cohen, Alon.
Application Number | 20020044534 09/982564 |
Document ID | / |
Family ID | 24766497 |
Filed Date | 2002-04-18 |
United States Patent
Application |
20020044534 |
Kind Code |
A1 |
Cohen, Alon |
April 18, 2002 |
Apparatus and method for multi-station conferencing
Abstract
A system and method for multi-media half-duplex conferencing in
a computer network comprising a plurality of stations and a control
server. The method and system include, respectively, means for and
the steps of receiving a packet at the server from one station of
the plurality of stations including a digital representation of
information of at least one information type selected from audio
information and video Information, identifying the station as a
transmitting station, blocking packets transmitted from the
plurality of stations at the server except from the first
transmitting station, distributing packets from the transmitting
station, thereby providing audio information generated by a user of
the transmitting stations to users of the other stations of the
plurality of stations and repeating the steps of receiving,
identifying, blocking and transmitting for a different one of the
plurality of station, thereby replacing the transmitting station
with a different transmitting station, thereby providing the
half-duplex multi-station conference.
Inventors: |
Cohen, Alon; (Rishon LeZion,
IL) |
Correspondence
Address: |
DARBY & DARBY P.C.
805 Third Avenue
New York
NY
10022
US
|
Assignee: |
VocalTec Communications
Ltd.
|
Family ID: |
24766497 |
Appl. No.: |
09/982564 |
Filed: |
October 16, 2001 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
09982564 |
Oct 16, 2001 |
|
|
|
08688959 |
Jul 31, 1996 |
|
|
|
Current U.S.
Class: |
370/263 ;
370/386 |
Current CPC
Class: |
H04M 3/566 20130101;
H04M 3/567 20130101; H04L 12/64 20130101 |
Class at
Publication: |
370/263 ;
370/386 |
International
Class: |
H04L 012/50 |
Claims
1. A method for multi-media half-duplex conferencing in a computer
network comprising a plurality of stations and a control server,
the method comprising the steps of; receiving a packet at said
server from one station of said plurality of stations including a
digital representation of information of at least one information
type selected from audio information and video information:
identifying said station as a transmitting station; blocking
packets transmitted from said plurality of stations at said server
except from said first transmitting station; distributing packets
from said transmitting station, thereby providing audio information
generated by a user of said transmitting stations to users of the
other stations of said plurality of stations; and repeating said
steps of receiving, identifying, blocking and transmitting for a
different one of said plurality of station, thereby replacing said
transmitting station with a different transmitting station, thereby
providing said half-duplex multi-station conference.
2. A method according to claim 1 wherein said step of replacing
comprises the steps of receiving a packet indicating an end of
transmission of said representation of said Information; and
receiving a packet from a different station, thereby providing said
identification of said second transmitting station.
3. A method according to claim 1 wherein said step of replacing
comprises the steps of not receiving packets from said transmitting
station for a predetermined period of time; and receiving a packet
from said second station after said predetermined period of time,
thereby providing said activation of said second transmitting
station.
4. A method according to claim 1 and further comprising the step of
visually indicating to said users which user utilizing the station
which is said transmitting station.
5. A method according to claim 4 wherein said step of indicating
comprising the steps of: transmitting a packet including a user
Identification from said first station to said control server;
adding said user identification to a participants list of users
participating is said half-duplex conference, thereby providing a
current participants list; storing said current identification list
with an indication which station is the current transmitting user;
providing said user identification list in said stations; and
displaying said identification list including said indication of
said current transmitting user.
6. A method according to claim 5 wherein said step of storing
comprises the steps of: storing an update of said current
participants list with an indication which station is the current
transmitting user; retrieving said update in said stations; and
displaying said update including said indication of said current
transmitting user.
7. A method for visually indicating to participants of a
multi-station conference, which participant is the current active
participant, the method comprising the steps of: providing a list
of participants in said multi-station conference; determining a
participant as a currently active participant; and indicating to
other participants of said multi-station conference who is the
currently active participant or participants.
8. A method according to claim 7 wherein said step of indicating
comprising the steps of: providing said participants list or an
updated portion thereof with an indication of the currently active
participant; and displaying said identification list including said
indication of said current active participant or participants.
9. A method according to claim 7 wherein said steps of providing
said participant list and said step of providing are independent of
said step of indicating.
10. A method according to claim 7 wherein said conference is a
half-duplex multi-station conference or a full-duplex multi-station
conference.
11. A system for multi-media half-duplex conferencing in a computer
network comprising a plurality of stations and a control server
comprising: means for receiving a packet at said server from one
station of said plurality of stations including a digital
representation of information of at least one information type
selected from audio information and video information; means for
activating said station as a transmitting station; means for
blocking packets from said plurality of stations except from said
first transmitting station; means for distributing packets from
said transmitting station, thereby providing audio information
generated by a user of said transmitting stations to users of the
other stations of said plurality of stations; and means for
repeating said steps of receiving, activating, blocking and
transmitting for a different one of said plurality of station,
thereby providing said half-duplex multi-station conference.
12. A system according to claim 11 wherein said means for replacing
comprises means for receiving a packet indicating an end of
transmission of said representation of said information; and means
for receiving a packet from said different one of said plurality of
stations, thereby providing said activation of said second
transmitting station.
13. A system according to claim 11 wherein said means for replacing
comprises means for determining non-receipt of packets from said
transmitting station for a predetermined period of time; and means
for receiving a packet from said different one of said plurality of
stations after said predetermined period of time, thereby providing
said activation of said second transmitting station.
14. A system according to claim 11 and further comprising means for
visually indicating to said users which user utilizing the station
which is said transmitting station.
15. A system according to claim 14 wherein said step of indicating
comprising the steps of: transmitting a packet including a user
identification from said first station to said control server;
adding said user identification to an identification list of users
participating is said half-duplex conference, thereby providing a
current identification list; storing said current identification
list with an indication which station is the current transmitting
user; retrieving said user identification list in said stations and
displaying said identification list including said indication of
said current transmitting user.
16. A system according to claim 15 wherein said means for storing
comprises: means for storing an update of said current
identification list with an indication which station is the current
transmitting user; means for retrieving said update in said
stations; and means for displaying said update including said
indication of said current transmitting user.
17. A system for visually indicating to participants of a
multi-station conference, which participant is the current active
participant comprising: an operator for providing a participant
lists or an update thereof; and a conference bridge server
connected to first means for determining a currently active
participant and to second means independent of said first means for
providing said visual indication of said currently active
participant to said participants of said multi-station
conference.
18. A system according to claim 17 wherein said conference bridge
server comprises: a CPU for receiving said participant lists or
said update thereof; a storage unit for storing said participant
lists and said updates thereof; and a voice activity unit connected
to said first means for detecting said currently active
participant, wherein said CPU is operative to provide to said
participants said participants list or an update thereof upon with
an indication of said currently active user upon detecting a
currently active user by said voice activity unit.
19. A system according to claim 17 wherein said first means are
telephony means and said second means are computer network
means.
20. A system according to claim 17 wherein said conference is a
half-duplex multi-station conference or a full-duplex multi-station
conference.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a method and system for
half-duplex multimedia multi-station conferencing over a network
generally and more particularly to a method and system for
half-duplex audio multi-station conferencing over a network.
BACKGROUND OF THE INVENTION
[0002] Wide Area Computer Networks (WAN), in particular the
INTERNET network, allow users to communicate multimedia information
therebetween. For Example, the Internet Phone, commercially
available from VocalTec Inc. of New Jersey, enable audio
conferencing between two parties using two computer stations
connected to the INTERNET and equipped with the INTERNET PHONE.TM.
application.
[0003] In another application, multi-station multi-media
conferencing is provided. In multi-station conferencing, a number
of users employ their computer station in order to hold a
conference. Generally speaking, two types of multi-station
conferencing exist, namely, full-duplex conferencing in which each
user may speak and hear audio information, i.e. is able to
simultaneously transmit and receive voice packets, and half-duplex
conferencing in which one station is determined to be the current
transmitting station at a time.
[0004] Full-duplex conferencing requires a mixing mechanism by
which voice packets transmitted by each station are mixed in a
network server so as to avoid the need to resolve according to
predetermined criteria which participant will be the active
participant. Obviously, mixing mechanisms directed to full duplex
conferencing are costly and difficult to implement and require in
addition a supplemental mechanism for self-hearing cancellation,
such as an echo canceling algorithm.
[0005] Half-duplex conferencing requires a mechanism which will
resolve who will be the user allowed to speak to all other at any
particular time. In prior art half-duplex and conferencing, a
resolving mechanism based on an arbitration procedure between voice
packets, for example the procedure described in U.S. Pat. No.
5,434,797 to Barris is implemented.
[0006] Another drawback associated with conferencing systems in
general and with multi-media multi-station conferencing in
particular is that it is sometimes difficult for one participant to
recognize who is the current participant. This problem is
particularly difficult in multi-station network conferencing, such
as in INTERNET multi-station conferences where participants which
are not familiar with each other have to recognize who is the
current participant.
SUMMARY OF THE INVENTION
[0007] An object of the present invention is to provide an improved
method for half-duplex multi-media multi-station conferencing in a
computer network.
[0008] In a preferred embodiment the multi-station half-duplex
conference is an audio conference or an audio and video
conference.
[0009] A further object of the present invention is to display the
current active participant in a multi-station conference.
[0010] There is thus provided, in accordance with a preferred
embodiment of the present invention, a method for multi-media
half-duplex conferencing in a computer network which includes a
plurality of stations and a control server. The method includes the
steps of receiving a packet at the server from one station of the
plurality of stations including a digital representation of
information of at least one information type selected from audio
Information and video information, identifying the station as a
transmitting station, blocking packets transmitted from the
plurality of stations at the server except from the first
transmitting station, distributing packets from the transmitting
station, thereby providing audio information generated by a user of
the transmitting stations to users of the other stations of the
plurality of stations; and repeating the steps of receiving,
identifying, blocking and transmitting for a different one of the
plurality of station, thereby replacing the transmitting station
with a different transmitting station, thereby providing the
half-duplex multi-station conference.
[0011] Further, according to a preferred embodiment of the present
invention, the step of replacing includes the steps of receiving a
packet indicating an end of transmission of the representation of
the information and receiving a packet from a different station,
thereby providing the identification of the second transmitting
station.
[0012] According to an alternative embodiment, the step of
replacing includes the steps of not receiving packets from the
transmitting station for a predetermined period of time and
receiving a packet from the second station after the predetermined
period of time, thereby providing the activation of the second
transmitting station.
[0013] In accordance to a preferred embodiment of the present
invention, the method also includes the step of visually Indicating
to the users which user utilizing the station which is the
transmitting station. Preferably, this step includes the steps of
transmitting a packet including a user identification from the
first station to the control server, adding the user Identification
to a participants list of users participating in the half-duplex
conference, thereby providing a current participants list, storing
the current identification list with an indication which station Is
the current transmitting user, providing the user Identification
list in the stations and displaying the identification list
including the Indication of the current transmitting user.
[0014] Further, the step of storing preferably includes the steps
of storing an update of the current participants list with an
indication which station is the current transmitting user,
retrieving the update in the stations and displaying the update
including the indication of the current transmitting user.
[0015] There is also provided, according to a preferred embodiment
of the present invention, a system for multi-media half-duplex
conferencing in a computer network which includes a plurality of
stations and a control server which is capable of operating in
accordance to the methods of the present invention.
[0016] There is further provided in accordance with a preferred
embodiment of the present invention, a method for visually
indicating to participants of a multi-station conference, both
half-duplex and full-duplex conferences, which participant is the
current active participant. The method includes the steps of
providing a list of participants in the multi-station conference,
determining a participant as a currently active participant and
indicating to other participants of the multi-station conference
who is the currently active participant or participants.
[0017] In a preferred embodiment the step of indicating includes
the steps of providing the participants list or an updated portion
thereof with an indication of the currently active participant and
displaying the identification list including the indication of the
current active participant or participants.
[0018] Further, according to a preferred embodiment of the present
invention, the steps of providing the participant list and the step
of providing are independent of the step of indicating.
[0019] There is also provided, according to a preferred embodiment
of the present invention, a system for visually indicating to
participants of a multi-station conference, both half-duplex and
full-duplex, which participant is the current active participant.
The system includes a human or automatic operator for providing a
participant lists or an update thereof and a conference bridge
server connected to first means, preferably but not limited to
telephone means, for determining a currently active participant and
to second means, preferably but not limited to computer network
means, independent of the first means for providing the visual
indication of the currently active participant to the participants
of the multi-station conference.
[0020] In a preferred embodiment, the conference bridge server
includes a CPU for receiving the participant lists or the update
thereof, a storage unit for storing the participant lists and the
updates thereof and a voice activity unit connected to the first
means for detecting the currently active participant The CPU Is
operative to provide to the participants list or an update thereof
upon with an Indication of the currently active user upon detecting
a currently active participant or participants by the voice
activity unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The present invention will be understood and appreciated
more fully from the following detailed description taken in
conjunction with the appended drawings in which:
[0022] FIG. 1 is a schematic block diagrams of a Wide Area Network
for providing half-duplex multimedia multi-station conferencing,
constructed and operative in accordance with a preferred embodiment
of the present invention;
[0023] FIG. 2 is a schematic block diagram illustration of a
resolving mechanism for determining the current active multimedia
station of the network of FIG. 1;
[0024] FIG. 3 Is a schematic block diagram illustration of a
preferred method for displaying the active participants in the
multimedia multi-station conference held over the network of FIG.
1;
[0025] FIG. 4 is a schematic block diagrams of a system for
providing multistation conferencing, constructed and operative In
accordance with a preferred embodiment of the present invention;
and
[0026] FIG. 5 is a schematic block diagram illustration of a
preferred method for operating the system of FIG. 4.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
[0027] Reference is now made to FIG. 1 which illustrates a Wide
Area Network (WAN), generally referenced 10, for providing
half-duplex multi-media multi-station conferencing, constructed and
operative In accordance with a preferred embodiment of the present
Invention. In a preferred embodiment, the WAN is the INTERNET.
[0028] In the preferred embodiment, WAN 10 is operative to provide
half-duplex multi-station audio conferencing and the present
Invention is described by way of a nonlimiting example with respect
thereto.
[0029] WAN 10 comprises a control server 12, a plurality of
multimedia computers 14 of which four are shown as a non limiting
example in the illustrated embodiment and referenced 14A, 14B, 14C
and 14D. In a preferred embodiment server 12 and stations 14 are
physically remote one from the other and are connected via the
INTERNET network Multimedia computers 14 may be any suitable
multimedia computer, such as a personal computer equipped with an
INTERNET connection and audio transceiving application. An example
of a suitable multimedia computer 14 is the PACKARD BELL of the
U.S. personal computer equipped with the INTERNET PHONE.TM.
application. The INTERNET PHONE.TM. gateway application,
commercially available from VocalTec Inc. of New Jersey, U.S.A, may
be implemented with any other suitable personal computer as
well.
[0030] In the illustrated embodiment WAN 10 also comprises a
telephony gateway 16 equipped with the INTERNET PHONE.TM. gateway
application connected to a conventional telephone and enables it to
operate as one of the WAN audio transceiving applications.
[0031] Each of stations 14 and gateway 16 comprises a voice
activity detection mechanism, such as the one incorporated in the
INTERNET PHONE.TM. which is sensitive to voice signals representing
audio information generated by respective users of stations 14 and
telephone 18.
[0032] These transmitted voice packets are utilized to determine
the current speaker in the half-duplex multi-station conference as
described in detail with reference to FIG. 2 hereinbelow.
[0033] FIG. 2 illustrates a preferred method of operating the
multi-station multi-media conference by server 12. First, a step of
initialization takes place. In this step, parameters such as the
maximal number of participants can be determined. Participants from
stations 14 and telephone 18 may now connect to the half-duplex
conference. In step 21, server 12 receives a packet or packets from
a first station, say 14A of the plurality of stations 14. The
packet or packets indicate the beginning of information
transmission in at least one type of media. In the preferred
embodiment server 12 receives audio packets indicating the
beginning of a speech burst in the format provided by the INTERNET
PHONE.TM..
[0034] In step 22, server 12 identifies station 14A as the current
transmitting station. Therefore, as indicated in step 23, server 12
will block packets from all other stations 14 and telephony gateway
16 and will continue to receive packets from current transmitting
station 14A.
[0035] Each received packet is generally immediately distributed as
indicated by step 24 to stations 14B-14D and telephone 18 via
gateway 16, thereby providing audio information generated by the
user employing station 14A.
[0036] Server 12 replaces the current transmitting station with a
different one as indicated by steps 25 and 26 as follows. In one
operation mode, server 12 receives an end of information packet
indicating that no further packets are expected from station 14A.
Alternatively, or in addition thereto, server 12 detects an
interruption for a time period which is longer than a predetermined
time. A preferred Interruption time is one second. In either case,
if a packet representing an end of speech burst is received or if
the predetermined time threshold is exceeded without receiving a
packet, server 12 ceases the identification of station 14A as the
current transmitting station and expects to receive a packet from
any second station which will be set as the active station.
[0037] If a packet is received from a second station, say telephone
18 via gateway 16, the user utilizing telephone 18 becomes the
current speaker and telephone 18 becomes the current transmitting
station. Similarly, any of stations 14 may become the current
transmitting station.
[0038] It will be appreciated that the method of FIG. 2 is more
efficient and cost effective with respect to prior art conferencing
methods. Since the method of the present invention provides
half-duplex conferencing, it does not require complex mixing nor an
echo canceling algorithm. Furthermore, according to the method of
FIG. 2 each station 14 receives only a single stream of information
representing the information addressed by the current active
participant, therefore it requires less data handling and utilizes
more efficiently existing hardware and network bandwidth.
[0039] Moreover, since the method of the present invention is media
insensitive, i.e. It does not require any determination of the type
of media transmitted, it is applicable to any multi-media
information whether visual, graphic, midi or audio as described in
the preferred embodiment or any combination therebetween.
[0040] Reference is now made to FIG. 3 which illustrates a method
for indicating to the users of stations 12 and telephone 18 a user
identification of the user utilizing the station which is the
current transmitting station.
[0041] At step 31 a user which did not participate before in the
multi-station conference is joining the conference. Step 31 is
obviously required only if a new user is joining the conference.
Similarly, in step 32 if a new user joins, the name is added to an
identification list of the participants in the multi-station
conferencing. Otherwise, the method starts at step 33.
[0042] Step 33 includes the step of transmitting a packet including
a user identification from the transmitting station, say 14A to
control server 12. In step 34, the current user identification is
added to the Identification list of users participating is the
conference stored in server 12.
[0043] The updated list is then retrieved by or transmitted to each
station 14 and gateway 16 in its entirety as indicated by 35 or
only an updated version thereof as indicated by step 36. Finally,
as indicated by 37 the updated list or the entire list of
participant with the current user identification highlighted is
displayed.
[0044] It will be appreciated that the display in stations 14 is
done on the computer display whereas similar display with respect
to telephone 18 requires an internal display or a different display
having independent connection to WAN 10.
[0045] It will be appreciated that while the present invention is
not limited by what has been described hereinabove and that
numerous modifications, all of which fall within the scope of the
present invention, exist. For example, while the present invention
has been described with reference to half-duplex multi-station
audio conferencing, the method and system of the present invention
is not limited thereto and is similarly applicable to video
half-duplex multi-station conferencing.
[0046] Another example described with reference to FIGS. 4 and 5
hereinbelow is to display to participants of any multi-station
conference the current speaker or speakers.
[0047] FIG. 4 illustrates a non limiting example of a telephony
multi-telephone conference. The system comprises a conference
bridge server 40 having two connection channels to each
participant, a telephony channel indicated by lines 41 which
includes a voice activity detection unit 42 and connected to a
telephone 43 for each user, and a display channel 43 connected to
display units 44 for each user.
[0048] Telephony units 43 and display units 44 may be separated and
operative on difference physical networks, a non limiting example
being the conventional telephony network and the INTERNET,
respectively or may be lumped as shown for the unit referenced 45.
For the INTERNET example, displays 44 may be similar to stations
14.
[0049] A preferred operation mode of the system of FIG. 4 is
described now with reference to FIG. 5. In step 50, the operator
46, a human operator or an automatic telephony operator acquires
the details of the participants in the conference. In step 51, the
network identification associated with each participant is
transmitted as a participants list to the conference bridge server
12 which stores a current participant list at storage unit 47.
[0050] It will be appreciated that steps 50 and 51 are repeated for
each new participant joining the conference, i.e. the operator 46
updates the participant lists and provide same to CPU 47 of server
40 for storing In storage unit 48.
[0051] The conference now begins and voice activation units 42
detect a current active user or users and provide same to CPU 47
which updates participant list stored in storage unit 48 with a
current active speaker or speakers as indicated by step 52.
[0052] Each participant can now connect to server 40 using its
display system for retrieving the current updated list of
participants with the active participant or participants, i.e. the
current speaker or speakers for display on his own display 44.
[0053] Alternatively, Displays 44 are continuously connected to
server 40 and server 40 periodically transmits an updated list of
participants with the current active participants to each of
displays 44.
[0054] It will be appreciated by persons skilled in the art that
the present invention is not limited to what has been particularly
shown and described hereinabove. Rather, the scope of the present
invention is defined only by the claims that follow:
* * * * *