U.S. patent application number 15/397712 was filed with the patent office on 2017-06-29 for duplicating digital streams for digital conferencing using switching technologies.
The applicant listed for this patent is Facebook, Inc.. Invention is credited to Scott K. Brown.
Application Number | 20170187610 15/397712 |
Document ID | / |
Family ID | 26832331 |
Filed Date | 2017-06-29 |
United States Patent
Application |
20170187610 |
Kind Code |
A1 |
Brown; Scott K. |
June 29, 2017 |
DUPLICATING DIGITAL STREAMS FOR DIGITAL CONFERENCING USING
SWITCHING TECHNOLOGIES
Abstract
Using switching technologies to duplicate packets of a digital
stream (e.g., digital video stream) sent from one workstation to
multiple recipient workstations, where the switching technologies
enable the multiple streams sent from the switch to the recipient
workstations to be generated from a single digital stream sent from
the sending workstation to the switch. Data units, such as video
data units, may be transmitted by using a switch to enable receipt
of a stream of data units including a payload portion and an
attribute portion from at least two conferencing participants. The
switch is used to duplicate at least a subportion of the payload
portion of a data unit within the stream of data units, and to
enable access to the duplicated subportion of the data unit by two
or more conferencing participants.
Inventors: |
Brown; Scott K.; (Marietta,
GA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Facebook, Inc. |
Menlo Park |
CA |
US |
|
|
Family ID: |
26832331 |
Appl. No.: |
15/397712 |
Filed: |
January 3, 2017 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
14702505 |
May 1, 2015 |
9537667 |
|
|
15397712 |
|
|
|
|
14688858 |
Apr 16, 2015 |
9521006 |
|
|
14702505 |
|
|
|
|
13620820 |
Sep 15, 2012 |
9049032 |
|
|
14688858 |
|
|
|
|
13053903 |
Mar 22, 2011 |
8463853 |
|
|
13620820 |
|
|
|
|
11549934 |
Oct 16, 2006 |
7921157 |
|
|
13053903 |
|
|
|
|
10134439 |
Apr 30, 2002 |
7124166 |
|
|
11549934 |
|
|
|
|
60343182 |
Dec 31, 2001 |
|
|
|
60286964 |
Apr 30, 2001 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L 65/4038 20130101;
H04L 65/605 20130101; H04L 12/1813 20130101; H04L 12/1827 20130101;
H04L 65/403 20130101; H04L 45/16 20130101; H04L 12/1822 20130101;
H04N 7/147 20130101; H04L 51/04 20130101; H04L 29/06027 20130101;
H04N 7/15 20130101 |
International
Class: |
H04L 12/761 20060101
H04L012/761; H04N 7/14 20060101 H04N007/14; H04N 7/15 20060101
H04N007/15; H04L 29/06 20060101 H04L029/06 |
Claims
1. A method of transmitting data units, the method comprising:
using a switch to receive a stream of data units including a
payload portion and an attribute portion from at least two
conferencing participants; using the switch to duplicate at least a
subportion of the payload portion of a data unit within the stream
of data units; and using the switch to enable access to the
duplicated subportion of the data unit by two or more conferencing
participants.
2-27. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S.
application Ser. No. 14/702,505, filed May 1, 2015, now issued as
U.S. Pat. No. 9,537,667, which is now a continuation of U.S.
application Ser. No. 14/688,858, filed on Apr. 16, 2015, now issued
as U.S. Pat. No. 9,521,006, which is a continuation of U.S.
application Ser. No. 13/620,820, filed on Sep. 15, 2012, now issued
as U.S. Pat. No. 9,049,032, which is a continuation of U.S.
application Ser. No. 13/053,903, filed on Mar. 22, 2011, now issued
as U.S. Pat. No. 8,463,853, which is a continuation of U.S.
application Ser. No. 11/549,934, filed on Oct. 16, 2006, now issued
as U.S. Pat. No. 7,921,157, which is a continuation of U.S.
application Ser. No. 10/134,439, filed Apr. 30, 2002, now issued as
U.S. Pat. No. 7,124,166, which claims priority to and the benefit
of U.S. provisional application No. 60/343,182, filed Dec. 31, 2001
and U.S. provisional application No. 60/286,964, filed Apr. 30,
2001. Each of the aforementioned patents and applications are
hereby incorporated by reference in their entirety.
TECHNICAL FIELD
[0002] The following description relates to using switching
technologies to stream media in digital conferencing
applications.
BACKGROUND
[0003] Video conferencing generally describes a process whereby
conferencing participants can communicate remotely with one another
through the use of video equipment that typically includes some
form of camera and a video display. Increased usage of the Internet
has resulted in an increased demand for video conferencing and a
corresponding need for cost effective multimedia communications
solutions.
SUMMARY
[0004] In one general aspect, data units may be transmitted by
using a switch to receive from at least two conferencing
participants a stream of data units that each include a payload
portion and an attribute portion. The switch duplicates at least a
subportion of the payload portion of a data unit within the stream
of data units, and enables access to the duplicated subportion of
the data unit by two or more conferencing participants.
[0005] In another general aspect, a conferencing participant may
participate in an electronic conference by interfacing with a
network that includes a switch that duplicates the stream of data
units sent by two or more conferencing participants and makes the
duplicated stream of data units accessible to more than one
conferencing participant. The streams are received from the switch,
with each stream including a payload portion that has been
duplicated by the switch and an attribute portion that has been
transmitted by more than one other conferencing participant.
[0006] In another general aspect, a conferencing participant
participates in an electronic conference by interfacing with a
network that includes one or more switches capable of duplicating
at least a payload portion of a data unit within a stream of data
units. The conferencing participant transmits the stream of data
units to the switches for duplication of at least the payload
portion for transmission to two or more conferencing
participants.
[0007] In another general aspect, a conferencing participant
participates in an electronic conference by interfacing with a
network that includes a switch capable of duplicating a stream. The
participant transmits a stream to the switch and receives
duplicated streams from the switch.
[0008] Implementations may include one or more of the following
features. For example, the data unit may include an Internet
Protocol packet. The attribute portion of the data unit may include
an Internet Protocol header, or one or more pieces of layer three
information.
[0009] Implementations may include using the switch to generate and
associate different attribute portions with duplicates of the
payload portion generated by the switch. Using the switch to
duplicate at least the payload portion may include duplicating only
the payload portion of the data unit. Using the switch to associate
different attribute portions with the data unit and duplicates of
the payload portion may include specifying destination information
that differs among the duplicates of the payload portion. Using the
switch to generate and associate different attribute portions may
include changing an IP destination address. Changing the IP
destination address may include changing the IP destination address
to an IP address corresponding to one or more conferencing
participants to which access to the payload portion will be
enabled.
[0010] Using the switch to duplicate may include using the switch
to duplicate the payload portion and the attribute portion. The
switch may enable the conferencing participants to access
duplicated subportions of data units in response to receiving a
request to access the stream of data units. The request may be
received from at least a requesting one of the two or more
conferencing participants, or from a device other than the
conferencing participants.
[0011] Using the switch to enable access to the duplicated
subportions of the data unit may include transmitting two or more
duplicated subportions to two or more conferencing participants
using the switch. Using the switch to enable access to the
duplicated subportions of the data unit by two or more conferencing
participants may include transmitting two or more duplicated
subportions from a transmitting participant to all of the
conferencing participants using the switch, or from all of the
conferencing participants to all of the conferencing participants
using the switch. Transmitting two or more duplicated subportions
from all of the conferencing participants to all of the
conferencing participants may include enabling the switch to filter
an originating stream so that a stream of data units from an
originating conferencing participant is not transmitted back to the
originating conferencing participant.
[0012] Implementations may include partitioning content from a
stream that includes a combination of a forwarded signal and a
filtered signal. The forwarded signal may differ from the filtered
signal. For example, the underlying media format may be transcoded
to a different bit rate.
[0013] Implementations may include determining whether one of the
conferencing participants is attempting to actively participate.
Using the switch to enable access to the duplicated subportions of
the data unit by two or more conferencing participants may include
enabling access to the streams of the conferencing participants
attempting to actively participate most recently. The streams of
conferencing participants that have not attempted to actively
participate may not be duplicated.
[0014] Using the switch to enable access to the duplicated
subportions may include prioritizing conferencing participants to
determine which streams of the conferencing participants are
duplicated. Access to the streams of conferencing participants with
higher priorities may be enabled before enabling access to the data
streams of conferencing participants with lower priorities. A
priority for a participant may be specified by one of a service
provider, a conference organizer, or a conference manager.
[0015] Using a switch to enable access to the duplicated subportion
of the data unit by two or more conferencing participants may
include using the conference manager to designate which of the
conferencing participants' data streams are enabled to be accessed.
Perceivable output may be displayed based on the stream of data
units.
[0016] The details of one or more implementations are set forth in
the accompanying drawings and the descriptions below. Other
features and advantages will be apparent from the description and
drawings, and from the claims.
DESCRIPTION OF DRAWINGS
[0017] FIG. 1 is a block diagram illustrating a communications
system that uses a switch to duplicate digital streams and enable
digital conferencing among multiple conferencing participants.
[0018] FIG. 2A is a block diagram illustrating several conferencing
applications that may be available to an exemplary conferencing
participant.
[0019] FIG. 2B is a block diagram illustrating an exemplary display
used to make known and/or available the conferencing applications
described with respect to FIG. 2A.
[0020] FIG. 3 is a diagram of a switch interfacing with four
conferencing participants.
[0021] FIG. 4 is a flow chart illustrating the operation of a
switch in duplicating at least a subportion of a data unit in a
stream of data units and enabling conferencing participants to
access the duplicated subportion of the stream of data units.
[0022] FIG. 5 is a diagram illustrating the operation of a
conferencing participant in prioritizing among several duplicated
streams of data units for display.
[0023] Like reference symbols in the various drawings indicate like
elements.
DETAILED DESCRIPTION
[0024] In general, switching technologies may be used to duplicate
packets in a digital conference (e.g., digital video stream) sent
from one workstation as part of an electronic conference. The
switching technologies enable the multiple streams sent from the
switch to the recipient workstations to be generated from a single
digital stream sent from the sending workstation to the switch.
Thus, a terminal participating in the conference does not need to
transmit a stream for each participant.
[0025] By way of introduction, FIGS. 1-3 illustrate aspects of a
communications system that uses switching techniques to duplicate
digital streams to enable conferencing between multiple
participants. For brevity, in FIGS. 1-3, several elements are
represented as monolithic entities. However, as would be understood
by one skilled in the art, these elements each may include numerous
interconnected computers and components configured to perform a set
of specified operations and/or dedicated to a particular
geographical region. FIGS. 4 and 5 illustrate aspects of a
communications system that may or may not correspond to the logical
and/or physical aspects described with respect to FIGS. 1-3.
[0026] Referring to FIG. 1, a communications system 100 that is
capable of providing conferencing between multiple participants may
be structured and arranged to include two or more conferencing
participants 150A and 150B and communication software and hardware
that enables communications between them. More particularly, the
communications system 100 may include a transmitting participant
110 (optional), a network 120, a switch 130, a conference manager
135 (optional), a network 140, and conferencing participants 150A
and 150B. A conferencing participant 150A generally transmits one
or more streamed data units across network 120 to one or more
switches 130 that duplicate the data units or portions of the data
units and transmit the duplicated data units or portions to the two
or more conferencing participants 150A and 150B through network
140.
[0027] A transmitting participant 110 typically includes a computer
system that converts a media feed into a stream. Transmitting
participant 110 may be structured and arranged to convert the media
source (e.g., a video or audio feed) into data units for
transmission across a network 120. The transmitting participant 110
may include a general-purpose computer having a central processor
unit (CPU) and memory/storage devices that store data and various
programs such as an operating system and one or more application
programs. Other examples of a transmitting participant 110 include
a workstation, a server, a device, a special purpose device or
component, a broadcast system, other equipment, or some combination
thereof capable of responding to and executing instructions in a
defined manner. The transmitting participant 110 also typically
includes an input/output (I/O) device (e.g., one or more devices
having a video and/or audio input and conversion capability), and
peripheral equipment such as a communications card or device (e.g.,
a modem or a network adapter) for exchanging data with the network
120.
[0028] A communications link 115 is used to communicate data
between the transmitting participant 110 and the network 120.
Communications link 115 may include, for example, a telephone line,
a wireless network link, a cable network, or a direct
connection.
[0029] The network 120 typically includes hardware and/or software
capable of enabling direct or indirect communications between the
transmitting participant 110 and the switch 130. The network 120
may include a direct link between the transmitting participant 110
and the switch 130, or it may include one or more networks or
subnetworks between them (not explicitly shown). Each network or
subnetwork may include, for example, a wired or wireless data
pathway capable of carrying and receiving data. Examples of network
120 include the Internet, the World Wide Web, a WAN ("Wide Area
Network"), a LAN ("Local Area Network"), an analog or a digital
wired or wireless telephone network (e.g., a PSTN ("Public Switched
Telephone Network"), an ISDN ("Integrated Services Digital
Network"), or a xDSL ("any form of Digital Subscriber Loop")),
and/or a radio network, a television network, a cable network, a
satellite network, or some other delivery mechanism for carrying
data.
[0030] The switch 130 typically is structured and arranged to
receive streams of data units (e.g., from the transmitting
participant 110 and the conferencing participants 150A and 150B),
to duplicate the stream of data units., and to transmit the
duplicated streams to two or more conferencing participants 150A
and 150B.
[0031] In some implementations, the switch 130 is structured and
arranged to perform filtering and forwarding between different
domains at the same level of the protocol stack in the OSI ("Open
System Interconnection") reference model. For example, in some
networks, switch 130 may forward Ethernet frames between different
Ethernet segments. In another example, switch 130 may forward IP
packets between different IP subnets.
[0032] Generally, switch 130 includes a device that performs
network operations and functions in hardware (e.g., a chip or a
part of chip). In some implementations, the device may include an
ASIC ("Application Specific Integrated Circuit") that implements
network operations logic directly on a chip (e.g., logical gates
fabricated on a silicon wafer then manufactured into a chip). For
example, an ASIC chip may implement a logical gate structure in
silicon to perform filtering by receiving a packet, examining the
IP address of the received packet, and filtering based on the IP
address.
[0033] Implementations of the device included in the switch 130 may
use a Field Programmable Gate Array (FPGA). A FPGA is generally
defined as including a chip or chips fabricated to allow third
party designers to implement a variety of logical designs on the
chip. For example, a third party designer may load a design within
a FPGA to replace the received IP addresses with different IP
addresses, or may load a design within the FPGA to segment and
reassemble IP packets as they are modified while being transmitted
through different networks.
[0034] Implementations of the device included in the switch 130 may
include a network processor. A network processor generally is
defined to include a chip or chips for allowing software to specify
network operations to be performed. A network processor may perform
a variety of operations. One example of a network processor may
include several interconnected RISC ("Reduced Instruction Set
Computer") processors fabricated in a network processor chip. The
network processor chip may implement software on some of the RISC
processors to change an IP address of an IP packet. Other RISC
processors in the network processor chip may implement software
that determines which conferencing participants are receiving an IP
stream.
[0035] Although various examples of network operations were defined
with respect to different devices, each of the devices may to be
programmable and capable of performing the operations of the other
devices. For example, the FPGA device is described as the device
used to replace IP addresses and segment arid reassemble packets;
however, a network processor and ASIC are generally capable of
performing the same operations.
[0036] Data units handled by switch 130 may be accessed by or sent
to conferencing participants 150A and 150B through network 140. As
such, network 140 is structured and arranged to receive data units
transmitted from the switch 130 for transmission to the
conferencing participants 150.
[0037] The conference manager 135 may include one or more devices
capable of enabling an electronic conference of two or more
conferencing participants. The conference manager 135 may include a
controller (not shown) that processes instructions received from or
generated by a software application, a program, a piece of code, a
device, a computer, a computer system, or a combination thereof, to
direct operations of the conference manager 135. The instructions
may be embodied permanently or temporarily in any type of machine,
component, equipment, storage medium, or propagated signal that is
capable of being delivered to the conference manager 135 or that
may reside with the controller at the conference manager 135. The
conference manager 135 may include a general-purpose computer
(e.g., a personal computer) capable of responding to and executing
instructions in a defined manner, a system or a component in the
switch 130, other equipment, or some combination of these items
that is capable of responding to and executing instructions.
[0038] For instance, in one implementation, the conference manager
135 includes one or more scheduling, management, and authentication
applications (e.g., calendaring software) capable of establishing
and managing one or more electronic conferences. These scheduling
and authentication applications may run on a general purpose
operating system and a hardware platform that includes a general
purpose processor and specialized hardware for graphics,
communications and/or other capabilities. In another
implementation, conference manager 135 may include a switch
designation component (e.g., a server or program) that determines
the switch 130 with which the conferencing participants will be
communicating. For example, the conference manager 135 may be
structured and arranged to communicate to the conferencing
participants which specific switch will host the conference (e.g.,
duplicate and transmit the streams of data units), or to
communicate to the designated switch the required information and
authorization to host the conference.
[0039] Implementations of the conference manager 135 may include a
service provider or a conference organizer. For example, a service
provider may offer conferencing services and arrange or set up
conferences. In another example, a conference organizer (e.g., a
user putting together an electronic conference) may act both as a
conference manager 135 and a conferencing participant 150B.
[0040] The network 140 may include hardware and/or software capable
of enabling direct or indirect communications between the switch
130 and the conferencing participant 150. As such, the network 140
may include a direct link between the switch 130 and the
conferencing participant 150, or it may include one or more
networks or subnetworks between them (not shown). Each network or
subnetwork may include, for example, a wired or wireless data
pathway capable of carrying and receiving data. Examples of the
delivery network include the Internet, the World Wide Web, WANs,
LANs, analog or digital wired and wireless telephone networks
(e.g., PSTN, ISDN, or xDSL), radio, television, cable, satellite,
and/or any other delivery mechanism for carrying data. Network 120
and network 140 may share one or more hardware or software
devices.
[0041] Conferencing participants 150A and 150B may include one or
more devices capable of receiving the streams of data units
transmitted by switch 130 through network 140. The conferencing
participant 150A may include a controller (not shown) that
processes instructions received from or generated by a software
application, a program, a piece of code, a device, a computer, a
computer system, or a combination thereof, to direct operations of
the conferencing participant 150A. The instructions may be embodied
permanently or temporarily in any type of machine, component,
equipment, storage medium, or propagated signal that is capable of
being delivered to the conferencing participant 150A or that may
reside with the controller at the conferencing participant 150. The
conferencing participant 150 may include a general-purpose computer
(e.g., a personal computer) capable of responding to and executing
instructions in a defined manner, a workstation, a laptop, a PDA
("Personal Digital Assistant"), a wireless phone, a component,
other equipment, or some combination of these items that is capable
of responding to and executing instructions.
[0042] For instance, in one implementation, the conferencing
participant 150A includes one or more information retrieval
software applications (e.g., a browser, a mail application, an
instant messaging client, an Internet service provider client, or
an AOL TV or other integrated client) capable of receiving one or
more data units. The information retrieval applications may run on
a general purpose operating system and a hardware platform that
includes a general purpose processor and specialized hardware for
graphics, communications and/or other capabilities. In another
implementation, conferencing participant 150A may include a
wireless telephone running a micro-browser application on a reduced
operating system with general purpose and specialized hardware
capable of operating in mobile environments.
[0043] Generally, conferencing participant 150A participates in an
electronic conference by transmitting and receiving streams of data
units. However, implementations may include having conferencing
participants 150A participate in an a synchronous mode. For
example, an electronic conference may incorporate a news feed that
is being discussed and transmitted by a transmitting participant.
In another example, a briefing may be incorporated into an
electronic conference to enable wider participation. Other
asynchronous modes may include conferencing participants that
receive but do not transmit. For these and other reasons, aspects
of the transmitting participant 110 may resemble, but are not
limited to, aspects of the conferencing participant 150A.
[0044] Conferencing participant 150B may include a workstation that
is identical to conferencing participant 150A, or conferencing
participant 150B may include a device that differs from
conferencing participant 150A. For example, conferencing
participant 150A may include a PDA while conferencing participant
150B includes a workstation.
[0045] In another implementation, the conferencing participants
150A and 150B may have different input/output capabilities. For
example, one conferencing participant 150A may not have a camera
from which to generate video content. This may limit the
conferencing participant 150A to only sending an audio stream of
data units. In another implementation, the conferencing participant
150A may have limited graphical display capabilities (e.g., the
conferencing participant may be a PDA). The conferencing
participant 150A may receive text messages exchanged as part of the
electronic conference without receiving video content.
[0046] FIG. 2A illustrates conferencing applications 200A that are
available to an exemplary conferencing participant, such as the
conferencing participant 150A described in FIG. 1. The applications
depicted include video conferencing application 210A, image
conferencing application 220A, audio conferencing application 230A,
and text conferencing application 240A.
[0047] In general, the conferencing applications 200A are logically
organized from the top of the diagram down based on the resources
required by those applications. For example, video conferencing
applications 210A generally require more bandwidth than text
conferencing applications 240A. Similarly, the computational
resources required by the image and audio compression techniques to
compress, decompress and/or display media generally decrease from
video conferencing applications 210A to image conferencing
applications 220A to audio conferencing applications 230A to text
conferencing applications 240A. The resources required for one or
more applications may lead one or more conferencing participants to
participate in a less resource-intensive manner.
[0048] Typically, video conferencing application 210A encodes and
displays audio and video content. Implementations of video
conferencing application 210A use compression to reduce the
bandwidth consumed by transmitting the stream of data units. For
example, video conferencing protocols and techniques may reduce the
resolution, detail, or frame rate to reduce the bandwidth consumed.
In another example, the frame-to-frame differences may be encoded
for transmission instead of encoding each frame. Similar techniques
may be applied to the audio signal. For example, the sampling rate
of the audio signal may be reduced or the signal may be
compressed.
[0049] Image conferencing application 220A typically operates by
displaying one or more images to conferencing participants.
Although an image conferencing application may resemble, in some
implementations, a video conferencing application 210A with a low
frame rate, image conferencing application 220A typically has
non-video implementations. For example, a conferencing participant
may input a map into an electronic conference in which aspects of
the map are discussed. Other implementations may include inputting
a web page and/or a slide show for incorporation into the
electronic conference. In an implementation that resembles video
conferencing application 210A, an image of the conferencing
participant may be displayed in an audio conference when that
conferencing participant is speaking.
[0050] Audio conferencing application 230A involves the use of an
audio signal (e.g., a stream of data units) for incorporation into
an electronic conference. Typically, aspects of the audio
conferencing application may resemble aspects of the audio signal
in a video conferencing application 210A discussed above in that
the signal may be compressed.
[0051] Text conferencing application 240A involves the exchange of
text in an electronic conference. One common form of exchanging
text may feature the use of "chat" (e.g., a "chat room"). Other
text exchanging applications may include electronic mail, instant
messaging, SMS ("Short Message Service"), and proprietary
applications. Although some of the text exchanging applications may
not commonly appear as text conferencing applications 240A,
implementations may include using an underlying text exchanging
application as a transport mechanism in the conferencing
application. For example, an electronic conference may use
electronic mail to exchange text messages between conferencing
participants. In another example, when one conferencing participant
receives an instant message from another conferencing participant,
the instant message may be incorporated into the electronic
conference.
[0052] FIG. 2B illustrates one implementation for user environment
200B that indicates how several of the applications described with
respect to FIG. 2A may be collectively integrated into and form one
or more electronic conferencing applications. Typically, user
environment 200B operates on a computer system, such as the
conferencing participant 150A described with respect to FIG. 1.
User environment 200B may be structured and arranged to incorporate
video, images, text and audio as part of an electronic conference
as well as to share a common application or white board.
Specifically, user environment 200B includes video application
210B, image application 220B, audio conferencing application 230B,
text conferencing application 240B, and shared application
250B.
[0053] Typically, video application 210B features the display of
two other conferencing participants. In one implementation, each
conferencing participant has related text and audio conferencing
applications, and the first conferencing participant may be
represented by a video conferencing application 212B, an audio
conferencing application 232B, and a text conferencing application
242B. The second conferencing participant communicates with a video
application 214B, an audio conferencing application 234B, and a
text conferencing application 244B. A third conferencing
participant without video conferencing capability may communicate
using an imaging application 220B, an audio conferencing
application 236B, and a text conferencing application 246B.
[0054] The audio conferencing application 230B depicts an
implementation reflecting both common audio properties as well as
properties specific to their originating sources. More precisely,
general audio sources generated simultaneously may cause
destructive interference that make them difficult to understand.
For this reason, the audio channel may be structured so that one
audio channel is broadcast at a time. For example, implementations
may commonly manage all audio conferencing applications and apply
the same operating instructions to all received audio signals. In
one example, receiving several different audio sources
simultaneously may cause user confusion or comprehension
difficulties that may be avoided through the application of
filtering criteria generic to several users. Alternatively, it may
be desirable to provide source-specific operating and/or filtering
instructions. For example, where the different audio signals are
received at different strengths, the conferencing participant may
wish to reduce the volume from one conferencing participant and
increase the volume from another conferencing participant. In
another implementation, a conferencing participant may wish to
listen to everything from the conferencing participant in the audio
conferencing application 232B and "mute" or suppress the audio
conferencing application 234B. Each function may be enabled through
filtering controls displayed in user environment 200B.
[0055] A text conferencing application 240B may be a common
application to all participants (as represented by the application
appearing across the breadth of participants) or may be specific to
conferencing participants (as represented by text conferencing
applications 242B, 244B, and 246B. In one implementation of text
conferencing as a common application to all participants, when a
conferencing participant enters a message to be communicated, the
participant's identification may appear next to the message. In
implementations of conferencing participant-specific text
conferencing, the message may be displayed in association with its
source (e.g., underneath the corresponding participant).
[0056] FIG. 3 illustrates the operation of a switch in interfacing
with four conferencing participants to duplicate a stream of data
units. Conferencing participants 310, 320, 330 and 340 each
generally correspond to the conferencing participants described
with respect to FIGS. 1 and 2B, and switch 350 generally
corresponds to the switch 130 described with respect to FIG. 1.
[0057] Each of conferencing participant 310, 320, 330, and 340
transmits one stream of data units to the switch 350 for
duplication, and receives the duplicated streams of the other
participants in return from the switch 350. When each conferencing
participant receives the stream of data units of all the other
conferencing participants, the total number of streams sent out by
the switch is 2(N-1), where N is the number of conferencing
participants (i.e., the switch sends out six streams when there are
four participants). Although FIG. 3 illustrates having each
conferencing participant receive the stream of every other
conferencing participant, some implementations, particularly those
having a large number of conferencing participants, may use
intelligent selection and filtering techniques to reduce the number
of streams that are transmitted to each participant.
[0058] Furthermore, although one switch is depicted,
implementations may include using more than one switch. For
example, several users may initiate an electronic conference at one
switch. However, as additional users join the electronic
conference, additional switches may be added to support the
electronic conference. More specifically, in one implementation, a
first switch with limited available capacity may initiate a
connection to a second switch and send all new connections to the
second switch. Initiating the connection to the second switch may
include exchanging duplicated data units between the first and
second switches. In another example, when the second switch is
activated, several users may be transferred to the second switch to
be hosted. Implementations also may include intelligent switch
selection criteria that activate use of a second switch. For
example, when the switch determines that several users are located
in the same proximity, the switch may activate an additional switch
that is closer to the users to host the conference so that
duplicated streams are not being transmitted across large portions
of the network.
[0059] FIG. 4 illustrates the operation of a communications system
that uses a switch to duplicate at least a subportion of a stream
of data units and enable conferencing participants to access the
duplicated subportion of the stream of data units. The
communications system includes a conference manager 401, a switch
402, and several conferencing participants 403-406.
[0060] The conference manager 401 generally initiates the
conference (step 410) by, for instance, determining the identity of
a switch to host the conference and enabling the switch to host the
conference for two or more terminals. The conference may be
initiated in response to a request from a conferencing participant
to host the conference. The conference may be initiated by
allocating switch resources and authenticating conferencing
participants. Allocating switch resources may include load
balancing conferencing participants among more than one switch to
reduce network/switch congestion. Conferencing participants seeking
to join an electronic conference being hosted on a switch may be
authenticated to ensure conference confidentiality through a login
process or through a more elaborate set of steps, such as the
exchanging of public and/or private keys.
[0061] The request to initiate the conference is received by switch
402 (step 412), which also may verify and authenticate the message
(not shown). In response to the request, the switch 402 establishes
the conference (step 413). Although the conference is established
in response to a request from a conference manager, in some
configurations, the conference manager may reside on a conferencing
participant. In any event, the switch 402 establishes a conference
with conferencing participants 403-406 (step 414). Establishing the
connection generally enables a conferencing participant to
communicate a stream of data units to other conferencing
participants through the switch 402 and to receive streams of data
units from one or more other conferencing participants through the
switch 402.
[0062] Terminal 403 transmits a stream of data units (step 416)
that is received by the switch 402 (step 418). The switch
duplicates the stream of data units (step 420). In general,
duplicating the stream of data units includes receiving a data
unit, identifying a payload portion within the data unit, enabling
an instance of the payload to be modified for subsequent
transmission, and adding header information to the data unit to
reflect addressing information corresponding to one or more
recipients (e.g., conferencing participants 403-406). The stream
may be duplicated by copying the payload (e.g., content) of an IP
packet and changing the header information to reflect the IP
address of the destination conferencing participants for the
payload, by storing one or more IP packets for modification (e.g.,
the IP packet may be stored), by loading the packet to memory and
changing the IP destination address while preserving other
parameters in the header, or by other techniques. Operations may be
performed on the payload before transmitting the payload to a
conferencing participant. For example, the switch may transcode the
content of the payload to reduce the bit rate of the stream.
Generally, transcoding involves modifying a compressed signal so
that the characteristics of the modified signal correspond to
specified criteria. For example, a high bit rate video signal may
be transcoded by having the compressed video signal expanded, and
recompressed at a higher compression ratio before transmitting the
recompressed signal to a conferencing participant.
[0063] Another operation that may be performed includes
partitioning a combined signal to extract a forwarded signal and
remove a filtered signal. For example, a switch may remove an audio
signal from a combined audio-visual signal to reduce the bandwidth
required to transmit the forwarded signal.
[0064] Although FIG. 4 illustrates having terminals 403-406 receive
a transcoded and partitioned stream in steps 440-450, the diversity
of partitioning techniques is intended to demonstrate that various
fauns of partitioning are available rather than how a conferencing
participant would likely transition between different conferencing
applications. For example, a terminal that is capable of receiving
higher rate video applications would not likely request to
"downgrade" the received signal and received text instead.
Similarly, a conferencing participant capable of receiving video
generally would not elect to receive audio or lower rate video
instead.
[0065] In any event, regardless of the operations used during
duplication of the payload portion, the switch 402 ultimately
transmits the duplicated streams to conferencing participants
404-406 (step 422), and the conferencing participants 404-406
ultimately receive the stream of data units (step 424).
[0066] As part of participating in the electronic conference,
terminal 404 transmits a stream of data units (step 426). The
switch 402 receives (step 428) and duplicates (step 430) the stream
of data units, and then transmits (step 432) the duplicated streams
of data units which are received (step 434) by the conferencing
participants 403, 405 and 406.
[0067] As the third participant to transmit in an electronic
conference, terminal 405 transmits a stream of data units (step
435) that are received (step 436) by switch 402. The switch 402
performs operations on the data units. First, the switch 402
transcodes the data units (step 438). Typically, transcoding the
data units involves modifying the content portion or underlying
media format of a data unit to give the stream of data units a
desired characteristic. For example, lower quality video may be
decompressed and recompressed at a higher data rate with more
detail and resolution. In another example, the data rate may be
reduced by reducing the number of frames, and resolution, and/or by
using a lossier compression algorithm.
[0068] Next the switch 402 extracts or partitions content from
within the stream of data units (step 440) by, for example,
filtering a signal from a stream of data units whose content
combines more than one type of media (e.g., another signal). In
this manner, an audio signal may be extracted from a composite
audio-video signal.
[0069] Although FIG. 4 depicts transcoding as occurring before
partitioning, implementations may include performing those and
other steps in reverse order or simultaneously, or combining them
with other steps. For example, a stream of data units may have the
content of the received stream of data units expanded, and then may
extract the audio signal from the expanded stream.
[0070] The stream of data units is transmitted to terminals 403,
404, and 406 (step 442) in one or several formats. Additionally,
the transmitted data units may be received in various formats based
on the terminal to which they are transmitted. For instance,
terminal 403 may receive or filter an audio stream of data units
where the audio portion of a video signal has been partitioned
(step 446), terminal 404 may receive or filter a lower bit rate
video that has been transcoded (step 448), and terminal 406 may
receive or filter text that has been partitioned and an image that
has been transcoded from the underlying stream of data units (step
450).
[0071] Although a conferencing participant may receive output
streams of data units from several sources concurrently (e.g.,
using several displays on one or more display devices), the
conferencing participant may selectively receive and/or display a
subset of the multiple streams at any given instant. For example,
limited bandwidth to the conferencing participant may constrain the
number of simultaneous connections, or comprehension issues may
undermine the advantages otherwise obtained by receiving more than
one stream at a time. In an example of seven conferencing
participants, it may be advantageous to transmit data streams from
only four of the seven conferencing participants to the
conferencing participant to avoid bandwidth constraints or to avoid
confusing the recipient conferencing participant.
[0072] It may therefore become necessary to prioritize among
several competing or simultaneous data streams. For example, access
to the streams of data units may be limited to the conference
manager's stream and also those of the three most recent "active"
participants. A conferencing participant may be considered "active"
when the participant attempts to transmit during the electronic
conference by, for instance, speaking into a microphone, moving
while on camera, or typing text in a chat window.
[0073] FIG. 5 illustrates prioritization in an electronic
conferencing system that includes conferencing participants
501-503, a conference manager 504, and a conferencing participant
508. Conferencing participants 501-503 each transmit streams of
data units concurrently, while conferencing participant 508
determines which of the streams of data units to "watch" or
otherwise perceive.
[0074] In this example, conferencing participant 501 is talking
initially (step 510). In response, conferencing participant 508
perceives conferencing participant 501 (step 512).
[0075] If, in the course of the electronic conference, conferencing
participant 502 begins talking (step 514), conferencing participant
508 stops perceiving conferencing participant 501 (step 516) and
begins perceiving conferencing participant 502 (step 518). When
conferencing participant 501 begins talking again (step 520),
conferencing participant 508 stops perceiving conferencing
participant 502 (step 522) and begins perceiving conferencing
participant 501 (step 524) due to the fact that there is a new
"active" participant.
[0076] When a conferencing participant 503 is designated as having
a lower priority than the conference participant currently being
broadcast/perceived, other conferencing participants disregard
communications by that conferencing participant, as illustrated by
conferencing participant 508 disregarding communications by
conferencing participant 503 while higher-priority conferencing
participant 501 is being perceived (steps 526 and 528).
[0077] Participant prioritization may be implemented by
network-centric techniques or by conferencing participant-centric
techniques. For example, in a network-centric prioritization, the
switch may assign users different priorities designated by, for
example, conference manager 504. This prioritization may be
forwarded by a conferencing participant to the switch, which will
selectively duplicate and enable access to (e.g., transmit)
subportions of the stream of data units. If conflicts exist in
priorities, the conference organizer's priorities may take
precedence.
[0078] In a participant-centric technique, the receiving device may
determine which streams of data units the switches should filter
out. For example, the conferencing participant may elect to always
receive the stream of data units of a specified conferencing
participant. In yet another example, the conferencing participant
may receive filtering or prioritization parameters from a
conference manager 504.
[0079] To illustrate prioritization based at the conference manager
504, the conference manager 504 enables priority for conferencing
participant 502 when conferencing participant 501 is transmitting
(step 530). Conferencing participant 502 receives the priority to
transmit and have its stream duplicated before other conferencing
participants (step 532). In one implementation, the switch may
receive a prioritization message and selectively duplicate streams,
or may forward the prioritization message to conferencing
participants to allow the participants to selectively filter
signals. In another implementation, the conference manager 504 may
direct a prioritization message to conferencing participants
without using the switch to replicate the message. In yet another
example, the conference manager 504 may contact the transmitting
conferencing participant (e.g., conferencing participant 501) and
direct that participant to stop transmitting.
[0080] Regardless of the prioritization systems used, conferencing
participant 502 begins talking (step 534). In response,
conferencing participant 508 stops perceiving conferencing
participant 501 (step 536) and starts perceiving conferencing
participant 502 (step 538). Even though conferencing participant
502 receives a priority designation, conferencing participant 501
begins talking (step 540). However, because conferencing
participant 502 has been designated to be a higher priority than
conferencing participant 501, conferencing participant 508
disregards conferencing participant 501 (step 542).
[0081] Other implementations are within the scope of the following
claims. In particular, in some implementations, the switch may
perform one or more of the functions performed by the conference
manager. The switch, conferencing participants, and networks also
may be distributed across different entities in the communications
system and may make use of one or more agents and/or proxies to
perform certain functions. For example, the switch may receive a
forwarded list of conferencing requirements from a server that
arranges electronic conferences to be hosted on one or more
switches.
[0082] In one example, the conference may be launched by existing
applications. For example, a user may be participating in a chat
room. One of the users may propose a chat by entering a URL
("Uniform Resource Locator") that is launched by the users clicking
on the URL. For example, the URL may contain a hyperlink to
conference ID#10 on duplicating switch on IP address A.B.C.D.
Launching the URL `connects` the terminal to the duplicating
switch. Upon receiving the URL request from the terminal, the
duplicating switch may then look up ID#10 and determine that stream
IDs 10-14 are associated with ID#10 and transmit those streams to
the requesting terminal. The duplicating switch also may receive
stream ID 15 from the requesting terminal and send stream ID 15 to
other participants in conference ID#10.
* * * * *