U.S. patent application number 11/213511 was filed with the patent office on 2006-01-05 for real time replay service for communications network.
Invention is credited to Kiem-Phong Vo.
Application Number | 20060003751 11/213511 |
Document ID | / |
Family ID | 35405320 |
Filed Date | 2006-01-05 |
United States Patent
Application |
20060003751 |
Kind Code |
A1 |
Vo; Kiem-Phong |
January 5, 2006 |
Real time replay service for communications network
Abstract
The present invention is a method and system for buffering and
replaying a segment of a voice or data transmission. A connection
is established between two end nodes in the network. At an
intermediate node in the network between the end nodes, a
predetermined segment of the data is maintained in a memory as a
buffer. Upon receiving a request from one of the end nodes to
replay the segment, that segment is replayed and transmitted to the
requesting node. The request may be made by a user at one of the
end nodes, or may be made automatically after detecting corrupt
data. Because the buffering module is in the network, it need not
be incorporated in premises or mobile equipment. Because the
buffering module is remote from the requesting end node, the
replayed data does not contain errors introduced in the original
data between the buffering module and the requesting end node.
Inventors: |
Vo; Kiem-Phong; (Berkeley
Heights, NJ) |
Correspondence
Address: |
Law Office of Peter V.D. Wilde
301 East Landing
Williamsburg
VA
23185
US
|
Family ID: |
35405320 |
Appl. No.: |
11/213511 |
Filed: |
August 26, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10015516 |
Dec 13, 2001 |
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11213511 |
Aug 26, 2005 |
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Current U.S.
Class: |
455/414.1 ;
455/560 |
Current CPC
Class: |
H04L 1/1809 20130101;
H04L 47/26 20130101; H04L 47/10 20130101 |
Class at
Publication: |
455/414.1 ;
455/560 |
International
Class: |
H04Q 7/20 20060101
H04Q007/20 |
Claims
1. A method replaying a portion of a communication, comprising the
steps of: establishing a connection between first and second end
nodes thereby establishing a communication in progress; receiving,
at a buffering module in the connection from the first and second
end nodes, a communications signal sent from the second end node to
the first end node; maintaining in a memory a segment of the
communications signal that was transmitted through the buffering
module immediately previous to present time; receiving at the
buffering module a request to retransmit at least a portion of the
segment of the signal; and during the communication in progress
retransmitting from the buffering module to the first end node the
portion of the segment.
2. The method of claim 1, wherein at least a portion of the
connection is a PSTN, and wherein the step of establishing a
connection includes establishing a circuit-switched path.
3. The method of claim 2, wherein the request to retransmit is a
touch-tone sequence.
4. The method of claim 1, wherein the request to retransmit is an
in-band signal.
5. The method of claim 2, wherein the request to retransmit is an
out-of-band signal.
6. The method of claim 1, further comprising the step of receiving
at the buffering module a request to begin maintaining in a memory
a segment of the signal.
7. The method of claim 1, wherein at least a portion of the
connection is a packet switched network.
8. The method of claim 7, wherein the step of establishing a
connection comprises establishing a TCP/IP connection.
9. The method of claim 1, wherein the communications signal is a
voice signal, and the segment of the signal is a time segment of
the voice signal.
10. The method of claim 1, wherein the connection includes an
unreliable portion between the first node and the buffering
module.
11. The method of claim 1, wherein the first node is a handheld
device selected from a group consisting of a premises telephone
station set, a wireless telephone handset and a PDA.
12. A method replaying a portion of a communication, comprising the
steps of: establishing a connection between first and second end
nodes; receiving, at a buffering module in the connection remote
from the first and second end nodes, a communications signal sent
from the second end node to the first end node; maintaining in a
memory a segment of the communications signal that was transmitted
through the buffering module immediately previous to present time;
receiving at the buffering module a request to retransmit at least
a portion of the segment of the signal; retransmitting from the
buffering module to the first end node the portion of the segment;
and wherein the connection includes an audio bridge, and wherein
the step of maintaining in memory a segment of the signal comprises
maintaining in memory a segment of a signal sent by the audio
bridge to listening station sets.
13. The method of claim 1, further comprising the step of storing a
record of the retransmitting step in a message record
accumulator.
14. The method of claim 1, wherein the request to retransmit
received at the buffering module is automatically generated.
15. The method of claim 12, wherein the request is generated at the
first node.
16. A method for retransmitting a portion of a communication signal
to an end node in a network having an unreliable link, comprising
the steps of: buffering, at a location in the network on a side of
the unreliable link opposite the end node, a segment of the
communication transmitted immediately previous to present time;
receiving, at said location, a request to retransmit at least a
portion of the communication segment; and retransmitting the
portion of the segment across the unreliable link to the end
node.
17. The method of claim 16, wherein the unreliable link is a
wireless signal.
18. The method of claim 16, wherein the request to retransmit is a
touch-tone sequence.
19. The method of claim 16, wherein the first node is a handheld
device selected from a group consisting of a wireless telephone
handset and a PDA.
20. The method of claim 1, wherein the buffering module and the
first node are essentially co-located.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to network
communications services such as telephone services and data
services, and, more particularly, to a method for providing a
network-based, real-time replay service.
BACKGROUND OF THE INVENTION
[0002] A conversation is a forum in which participants attempt to
transfer information in real time to one another via means such as
voice, keyboards and wireless devices. Currently, communications
networks are structured with the assumption that such transferred
data are to be immediately consumed by the receiver(s). The data
disappear after being delivered. Examples of conversations
utilizing such communications networks include telephone calls,
conference calls, electronic drawing boards and instant
messaging.
[0003] Under field conditions, data transmission can be briefly
interrupted or lost. In such cases, instant replay can be helpful
to resynchronize the conversation. For example, during a
conversation conducted via a telephone network, voice data can be
corrupted by jitters on the network circuit or the data may be
received but not properly processed because the listener was
distracted by some external events (e.g., baby crying). In a
wireless telephone communication, the data may have passed through
most of the network intact, only to be corrupted by weather
conditions between the wireless base station and the handset.
Non-voice data may similarly be corrupted during transmission.
[0004] It is known to replay one-way streaming data such as TV
transmission. For example, the digital video recording devices used
in conjunction with TiVo, Inc.'s on-line service is capable of
buffering viewed content for immediate replay. Similarly, many
personal computer-based media players allow replay of streaming
media such as video webcasts through the use of a buffering system.
In each of those cases, the replay buffer is constructed at the
receiving node of the network, using data received at that node.
While useful in cases where the data is delivered intact to the
receiving node, such devices are not useful if the data is
corrupted upstream of the receiving node. Furthermore, the
receiving party must purchase, install and activate a software
and/or hardware device capable of buffering and replaying the
signal.
[0005] The scroll-back feature of a terminal device, used in
conjunction with instant messaging, provides some basic replay
capability in the case of a conversation involving multiple
parties. As with the buffering capability described above, that
capability is not effective in replaying communications that have
been corrupted upstream of the receiving node.
[0006] U.S. Pat. No. 5,477,487 describes a device that is used in
conjunction with a receiver such as a car radio. The device has
access to an audio signal produced by the receiver, and stores the
audio signal in the form of a digital buffer that may be replayed
by pressing a button. The buffer enables a listener, such as a
distracted car driver, to replay a missed portion of the one-way
broadcast. Again, the device is not useful if the broadcast was
missed because it did not reach the receiver.
[0007] Users of cell phones, personal digital assistants (PDA's)
and other mobile devices often encounter reception problems that
arise in the final, wireless portion of the connection. A buffering
system within the mobile device itself would not be helpful if a
communication became garbled before reaching the mobile device.
Because portability and compactness are important in such a device,
it is furthermore undesirable to add to the device the components
and circuitry necessary to implement a data buffering system.
[0008] It is therefore desirable to provide a method and apparatus
for buffering information for replay on demand by the receiving
party, wherein the replayed material is not affected by previous
transmission errors upstream of the receiver, and no additional
devices are necessary at the receiving node.
SUMMARY OF THE INVENTION
[0009] The present invention addresses those needs by providing a
feature of the data transfer medium that continuously stores
signals traveling through the network and replays them upon
request.
[0010] One embodiment of the invention is a method of replaying a
portion of a communication. In that method, a connection is
initially established between first and second end nodes. At a
buffering module in the connection remote from the first and second
end nodes, a communications signal sent from the second end node to
the first end node is received. A segment of that communications
signal that was transmitted through the buffering module
immediately previous to present time is maintained in a memory. At
the buffering module, a request is received to retransmit at least
a portion of the segment of the signal. That portion of the segment
is then retransmitted from the buffering module to the first end
node.
[0011] In that embodiment, at least a portion of the connection may
be a PSTN, and the step of establishing a connection may include
establishing a circuit-switched path. In that case, the request to
retransmit may be a touch-tone sequence. The request to retransmit
may be an in-band signal, or alternatively, an out-of-band
signal.
[0012] The method may also include the step of receiving at the
buffering module a request to begin maintaining in a memory a
segment of the signal. That step permits a user to initiate
buffering so that the replay service is available on demand.
[0013] At least a portion of the connection may be a packet
switched network. In that case, the step of establishing a
connection may include establishing a TCP/IP connection.
[0014] The communications signal may be a voice signal, in which
case the segment of the signal is a time segment of the voice
signal.
[0015] The connection may include an unreliable portion between the
first node and the buffering module. The unreliable portion may be
a wireless signal. The first node may, for example, be a premises
telephone station set, a wireless telephone handset, or a PDA. The
connection may include an audio bridge, in which case the segment
of the signal maintained in memory is a segment of a signal sent by
the audio bridge to listening station sets.
[0016] The method may also include the step of, after
retransmitting the portion of the segment, transmitting the signal
to the first end node beginning at a point immediately subsequent
to the portion of the segment. Alternatively, the signal may be
retransmitted beginning at a point in the signal received from the
second node at present time.
[0017] The method may include storing a record of the
retransmitting step in a message record accumulator.
[0018] The request to retransmit received at the buffering module
may be automatically generated. Automatic generation of the signal
may be triggered upon detection of corrupted data, and may be
performed at the first node.
[0019] Another embodiment of the invention is a method for
retransmitting a portion of a communication signal to an end node
in a network having an unreliable link. In that embodiment, a
segment of the communication transmitted immediately previous to
present time is buffered at a location in the network on a side of
the unreliable link opposite the end node. A request to retransmit
at least a portion of the communication segment is received at that
location, and the portion of the segment is retransmitted across
the unreliable link to the end node.
[0020] These and other advantages of the invention will be apparent
to those of ordinary skill in the art by reference to the following
detailed description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a network diagram illustrating one embodiment of
the present invention.
[0022] FIG. 2 is a network diagram including a PSTN illustrating
one embodiment of the present invention.
[0023] FIG. 3 is a flow chart illustrating one embodiment of the
present invention.
[0024] FIG. 4 is an example of a network diagram including a
wireless telephone network illustrating another embodiment of the
present invention.
[0025] FIG. 5 is an example of a network diagram including a
personal digital assistant and wireless network, illustrating one
embodiment of the present invention.
[0026] FIG. 6 is an example of a network diagram including an audio
bridge for conference calls, illustrating one embodiment of the
present invention.
[0027] FIG. 7 is a timing diagram illustrating an embodiment of the
present invention.
[0028] FIG. 8 is a timing diagram illustrating another embodiment
of the present invention.
DETAILED DESCRIPTION
[0029] An exemplary network 110 incorporating the invention is
illustrated in FIG. 1. The network 110 may be a telephone network
such as the Public Switched Telephone Network (PSTN), or any
network in which a signal traveling through the network is
available at some point as sequential information. The network
connects two end nodes 120, 130 through a connection 160. The
connection may be a dedicated connection between the two end nodes,
or, as is conventional in a PSTN, a connection set up specifically
for a conversation, and torn down after the conversation is
terminated. The end nodes 120, 130 are nodes wherein a signal
originates or terminates. A signal does not travel through an end
node to other nodes in the network.
[0030] The network 110 includes a buffering module 150 that is an
intermediate node within the connection 160. A signal traveling
through the connection between the end nodes 120, 130 passes
through the buffering module 150.
[0031] The buffering module 150 by virtue of its position has
access to information passing through the connection 160. The
buffering module 150 includes a processor 152 and a memory 153. The
processor 152 may accept instructions regarding the operation of
the buffering module, either through the network 110 or by other
means. For example, the processor may be instructed to begin
buffering data, to change the size of the data buffer, to replay a
quantity of buffered data or to perform other similar
operations.
[0032] In operation, the buffering module 150 stores in the memory
153 a segment of data passing through the connection 160
immediately previous to present time. In an exemplary embodiment,
the memory 153 is a static or dynamic random access memory having a
number of addresses in which to store data. The processor 152
receives the data from the connection 160 and writes the data to
the memory 153 as it continuously cycles through the addresses. In
that way, the address containing the oldest data in the memory 153
is always overwritten with the latest data from the connection. The
number of addresses and the size of the addressable memory segments
determine the storage capacity for buffered data. Where real-time
voice data is buffered, the storage capacity determines the time
interval represented by the buffer.
[0033] In a one embodiment of the buffering module 150, data is
continuously read from cycled memory addresses, and transmitted
along the connection 160 to a destination end node. When the
buffering module is not replaying stored data, the data is read
from an address immediately after it is written. To replay buffered
information, the processor 152 stops writing data to the memory 153
while continuing to read data. When writing stops, data read from
the cycled addresses will be the stored data starting with the
oldest and progressing to the newest. The replayed data repeat as
the addresses are cycled until writing is resumed. One skilled in
the art will be aware of many other buffering schemes that may be
used in the present invention without departing from the spirit
thereof.
[0034] In a two-way conversation, the data stored in the buffer may
include only data transmitted from the first end node to the second
end node. In that case, there may be a separate buffer in the
network for capturing data transmitted in the opposite direction.
Where separate buffers are employed, replay may include only data
transmitted in one direction, replayed from a single buffer, or may
include two-way data by replaying both buffers simultaneously.
Alternatively, the same buffer may be used to store data traveling
in both directions; for example, all voice data in a two-way
conversation may be stored in a single buffer.
[0035] An exemplary system for replaying real-time communications
in accordance with the present invention is shown in FIG. 2. That
system utilizes a PSTN 200, such as the well-known AT&T long
distance telephone network. The network provides long distance
telephone services for its subscribers, including the subscribers
associated with telephone stations S1 through S4. The
communications network 200 includes network switches such as
switches 210, 220. In the exemplary embodiment, the switches 210,
220 are switching offices interconnected to each other and to other
switching offices via a so-called inter-toll network; e.g., 211,
221, 231.
[0036] Each switch in the exemplary network is also connected to a
number of central offices such as central offices 240, 241. The
operation of a central office is well known and will not be
discussed in detail herein. A central office is arranged to send to
an associated switch of a network 200 a telephone call originated
at a calling telephone station set (herein the calling party or the
subscriber), e.g., S1, that has dialed a particular long distance
telephone number. A central office is also arranged to connect to a
telephone station set (herein the called party), e.g., S4, a call
that the central office receives from an associated switch.
[0037] The network 200 preferably includes an out-of-band signaling
system for setting up calls and for providing transaction and other
capabilities for subscribers such as caller ID, call waiting and
messaging services. The out-of-band signaling architecture includes
signal transfer points (STP's) 213, 223, 253 that function as
packet switches for routing signaling messages in the signaling
system. The STP's are interconnected by a signaling system network
212, 222, 232. The out-of-band signaling system may also extend
(not shown) to the central offices 240, 241 and subscriber stations
sets S1-S4. A preferred example of an out-of-band signaling system
is the ITU Signaling System 7 (SS7), which has been generally
accepted by the telecommunications industry. SS7 protocol uses
destination routing, octet-oriented fields, variable-length
messages and a maximum message length allowing for 256 bytes of
data.
[0038] Transactional message records of the network 200 are stored
by a message record accumulator 260, connected to one or more
network switches such as switch 210. The message record accumulator
260 collects relevant data, such as billing data, for each call
connected over the network 200. The relevant data collected by the
message record accumulator 260 is preferably a standardized message
record that may be used by other elements of the network for
purposes other than accessing a recording.
[0039] In a typical data recordation system used in a PSTN,
relevant data such as billing data is recorded for each toll call,
or connection, in a so-called automatic message account, or AMA,
message record. Typical message record fields are the originating
and terminating telephone numbers and elapsed time of call. The
accumulator 260 of the present invention furthermore may have
message record fields for recording use f the replay service of the
invention. For example, the message record may include fields for
recording that the service was used, for recording total replay
time, etc. In a typical system, the message records, which are
created for each call at a time substantially contemporaneous with
the termination of the call, are transmitted from an originating
switch to a message accumulation system such as accumulator 260.
The latter distributes the accumulated messages to appropriate
further processing systems that translate the AMA message records
into the industry-standard "exchange message interface," or EMI,
message record format. The EMI records are thereupon forwarded to a
rating system that, inter alia, computes the toll charges
applicable to the calls and adds an indication of those charges to
the EMI record. The records thus formed are forwarded to a billing
system in which they reside until processed to generate, typically,
"hard copy" bills that are mailed to subscribers.
[0040] A replay service adjunct 249 is included in the
communications network 200. The adjunct 249 operates, in accordance
with the invention, to process calls to or from a party according
to instructions received from the party. The replay service adjunct
may send and receive voice signals via the inter-toll network 221,
231, and may also send and receive signaling messages via the
out-or-band network 222, 232 and signal transfer point 253.
[0041] Associated with the replay service adjunct is buffering
module 250 that is connected to the network via the recording
service adjunct 249, as shown in FIG. 2, or via another switch such
as switches 210, 220. The buffering module is capable of sending
and receiving signals representing a voice telephone conversation
or data transmission through an in-band network portion 257, and
can also send and receive other messages related to the signal via
an out-of band network portion 256. As previously discussed, the
buffering module 250 includes a processor and memory.
[0042] In practice, two or more of the components including the
replay service adjunct 249, the buffering module 250 and the
message record accumulator 260 may be collocated at a common
network node. It is furthermore likely that a plurality of each
component would be deployed in a network.
[0043] In an exemplary method according to the invention, shown in
FIG. 3, a connection is established between the first and second
end nodes (step 310). The connection may be through any data
transfer medium capable of carrying a communications signal. In the
case of a PSTN, the connection is established by network switches
such as switches 210, 220 and STP's such as STP's 213, 223, 253 of
the network 200 (FIG. 2). The connection may alternatively be
established via some combination of circuit switching and packet
switching, and may include a circuit in the PSTN network and a
TCP/IP connection in the Internet. The connection may further
include, for example, a broadband phone, a wireless phone, a
wireless data network, a cable modem, or an instant messaging
module. The connection may be established for the purpose of
transmitting a conventional two-party telephone conversation, a
conference call, an electronic drawing board session or instant
messaging.
[0044] The replay service of the invention may be enabled before or
during a communication by receiving (step 312) a request to use the
replay service. In that embodiment, buffer memory is not consumed
unless a party intends to use the service. In another embodiment,
no initial request is made to use the service, and instead all
communications are buffered.
[0045] After a connection is established, a communication signal is
transmitted between the end nodes. The signal is received (step
315) at a buffering module within the communications network. The
signal is buffered (step 320) at the buffering module. As described
above, the signal is buffered by storing a segment of the signal
received at the buffering module immediately before present time.
In the case of a voice transmission, the buffer may store a
quantity of data received during a fixed time interval immediately
previous to the present time, such as a 15-second interval.
Alternatively, the buffer may store a fixed quantity of data, in
which case the buffered time interval varies with the data
transmission rate.
[0046] Once data is buffered, it is available for replaying and
resending upon a request originating at one of the end nodes. A
request is received (step 325) at the buffering module to resend
the buffered data. The request may be simply a signal to resend the
entire buffer, or may specify a portion of the buffer to be resent.
For example, the request may identify a time interval during the
buffered period that begins at time t and ends at time t+x, where x
is the length of the requested time interval. In any case, the
requested time interval for resending must fall within the buffered
period.
[0047] The request to resend all or a portion of the buffer may be
transmitted in-band to the buffering module through the network
itself. In the exemplary PSTN, the request may be transmitted in
the form of touch-tones; in a packet switched network, the request
may be contained in a packet addressed to the buffering module or
another node controlling the buffering module. The request may
alternatively be transmitted to the buffering module out-of-band.
For example, in the case of the PSTN illustrated in FIG. 2, the
request to replay the buffer may be transmitted to the replay
service adjunct 249 through the signaling system network 212, 222,
232.
[0048] Returning to the method of FIG. 3, if a request to resend is
received, all or part of the buffer is resent (step 330) in
response to the request. Resending the buffer includes replaying
the requested portion of the buffer as described above, and
directing the replayed data to another node. In the preferred
embodiment, the data is directed to the node that requested that
the communication be resent. Alternatively, the data may be
directed to another location, such as permanent storage. Such an
arrangement would, for example, permit a party to make a record of
the buffered portion of a conversation for later use.
[0049] One embodiment of the method and system of the present
invention incorporates the buffering module with a mobile voice
telephone system. As shown in FIG. 4, a wireless handset 410 and a
station set 440 are linked through a connection including a
wireless signal 412, a wireless base station 415, a mobile
switching center 420, a PSTN 425, and a central office 430. A
buffering module 450 is incorporated in the PSTN 425. As described
above, the buffering modules 450 includes a processor 452 and a
memory 453. One skilled in the art will recognize that the
buffering module 450 may be incorporated within other components in
the connection, such as nodes within the mobile switching center
420 or central office 430.
[0050] In the wireless telephone connection shown in FIG. 4, the
mobile switching center 420, the central office 430 and the PSTN
425 are generally reliable portions of the connection, and are not
likely to cause interruptions in communication requiring a replay
of a portion of a conversation. The wireless signal 412, however,
is frequently a source of transmission interruption, because it is
susceptible to RF interference, weather, obstacles such as tunnels
and buildings, etc. Because the buffering module 450 is within the
reliable portion of the connection, and removed from the unreliable
wireless signal 412, a party using the wireless handset 410 may
replay portions of an incoming transmission that were not received
due to such transmission interruptions. Advantageously, a
transmission that does not reach the handset 410 intact
nevertheless reaches the buffering module 450 and is therefore
available for replay. Furthermore, buffering and replaying within
the network does not necessitate additional equipment in the
handset 410.
[0051] In one embodiment of the invention, error correction when
communicating via noisy devices such as wireless telephones is
performed automatically. In the example of a wireless telephone
network, if the station set 440 transmits voice data correctly into
the network but due to noise in the wireless connection 412, the
handset 410 receives corrupted data, the handset 410 may detect the
corrupted data without intervention by the user, and automatically
request that the buffering module 450 resend the corrupted portion
of the conversation.
[0052] In another embodiment of the invention, shown in FIG. 5, a
mobile network terminal such as a personal digital assistant (PDA)
510 is connected to a server 535 through a connection including a
wireless signal 512, a base station 515, a mobile switching center
520, a PSTN 525, and a public packet-switched network 530 such as
the Internet. The PDA 510, the wireless signal 512, the base
station 515 and the mobile switching center 520 comprise a wireless
telephone network 501. Also incorporated in the wireless network
501 is a buffering module 550, which is positioned on the network
side of the wireless signal 512. While shown between the mobile
switching center 520 and the base station 515, the buffering module
550 may alternatively be placed within those elements or elsewhere
in the connection on the network side of the wireless signal
512.
[0053] The PDA 510 is generally used to access information from the
server 535 by making simple requests; for that reason, traffic flow
from the server to the PDA is generally much heavier than traffic
flow in the opposite direction. It is known in the art to verify
data received by the PDA by checksum or other technique, and, if
faulty data is detected, to request from the server another copy of
the faulty data. The request, and the duplicate data, must travel
the entire length of the connection, from the server 535 to the PDA
510. By placing the buffering module 550 at an intermediate node
within the connection at or near the wireless network, data flowing
to the PDA 510 may be retransmitted across a shorter portion of the
connection that still includes the wireless connection 512 where
transmission errors are most likely to occur. The wireless network
501 as a whole, including base station 515 and mobile switching
center 520, is thereby made more reliable as a data transfer medium
for transmitting data to the PDA 510, without further burdening
other networks in the connection between the PDA and the server
535.
[0054] In a conference call arrangement shown in FIG. 6, an audio
bridge 610 receives transmissions from each of the station sets
620, 621, 622, that are connected to the bridge though central
offices 610, 611, 612 and the PSTN 625. The audio bridge monitors
transmissions from each station set participating in the
conference, decides which station set user is speaking, and
selectively transmits an outgoing signal from the speaking station
set to the listening station sets.
[0055] A buffering module 650 is connected to the audio bridge 610
and receives all outgoing transmissions from the bridge. In that
arrangement, any of the station sets 620, 621, 622 may request the
buffering module 560 to replay a buffered portion of the
conversation as it was transmitted to the listening station
sets.
[0056] In the case of a voice communication, the replay of the
communication segment may replace a subsequent segment of the
original communication that was sent. As shown in FIG. 7, a
communication sent from a source may include segments 1 through 10,
but segments 3 and 4 are corrupted during transmission. The network
resends those segments, and they are received during the time in
which segments 5 and 6 would otherwise have been received. After
segments 3 and 4 have been replayed, the receiver resumes receiving
the communication as it is transmitted, starting with segment 7. In
that arrangement, the receiver never receives segments 5 and 6.
Such an arrangement is acceptable in voice transmissions, where the
receiver may request that the sender stop talking while the segment
is replayed.
[0057] In the arrangement of FIG. 8, segments 5 and 6 are delayed
by the buffer and are received by the receiver after segments 3 and
4 are replayed. Thereafter, subsequent segments are delayed by the
network and delivered to the receiver in order. Because no data is
lost in that arrangement, it is appropriate for data transfer as
opposed to voice communications. The network, however, must either
resynchronize by increasing the data transfer rate between the
buffer and the receiver, or continuously buffer data until a
communication is complete. In either case, at least temporarily,
memory is consumed that would otherwise be available for replay
buffering.
[0058] The foregoing Detailed Description is to be understood as
being in every respect illustrative and exemplary, but not
restrictive, and the scope of the invention disclosed herein is not
to be determined from the Detailed Description, but rather from the
claims as interpreted according to the full breadth permitted by
the patent laws. It is to be understood that the embodiments shown
and described herein are only illustrative of the principles of the
present invention and that various modifications may be implemented
by those skilled in the art without departing from the scope and
spirit of the invention. For example, the detailed description has
been described with particular emphasis on existing voice telephony
and data network architecture. However, the principles of the
present invention could be extended to other communications
architecture, such as Internet telephony, facsimile, instant
messaging or other data communications. Such an extension could be
readily implemented by one of ordinary skill in the art given the
above disclosure.
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