U.S. patent application number 13/036123 was filed with the patent office on 2012-07-05 for method and apparatus for distributing data in a short-range wireless communication system.
This patent application is currently assigned to MOTOROLA MOBILITY, INC.. Invention is credited to Yossi Y. Cohen, James M. Cornett.
Application Number | 20120171958 13/036123 |
Document ID | / |
Family ID | 46381155 |
Filed Date | 2012-07-05 |
United States Patent
Application |
20120171958 |
Kind Code |
A1 |
Cornett; James M. ; et
al. |
July 5, 2012 |
METHOD AND APPARATUS FOR DISTRIBUTING DATA IN A SHORT-RANGE
WIRELESS COMMUNICATION SYSTEM
Abstract
A short-range communication system, such as a Bluetooth
communication system, is provided that provides for a source
communication device to multiplex data packets that are intended
for different sink communication devices of multiple sink
communication devices into a single stream that is broadcast to all
of the multiple sink communication devices, and for each of the
multiple sink communication devices to decode only the data packets
intended for that sink communication device. Further, the
communication system provides for a first sink communication device
of the multiple sink communication devices to negotiate connection
parameters associated the broadcast and to convey the negotiated
connection parameters to a second sink communication device of the
multiple sink communication devices, as opposed to each sink
communication device setting up its own connection with the source
communication device.
Inventors: |
Cornett; James M.;
(Braselton, GA) ; Cohen; Yossi Y.; (Laguna Niguel,
CA) |
Assignee: |
MOTOROLA MOBILITY, INC.
Libertyville
IL
|
Family ID: |
46381155 |
Appl. No.: |
13/036123 |
Filed: |
February 28, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61429001 |
Dec 31, 2010 |
|
|
|
Current U.S.
Class: |
455/41.2 |
Current CPC
Class: |
H04W 48/16 20130101;
H04W 84/18 20130101; H04L 63/08 20130101; H04W 28/18 20130101; H04W
76/00 20130101; H04L 63/0428 20130101; H04W 4/80 20180201 |
Class at
Publication: |
455/41.2 |
International
Class: |
H04B 7/00 20060101
H04B007/00 |
Claims
1. A method for distributing data in a short-range wireless
communication system, the method comprising: negotiating, by a
first sink communication device, a connection with a source
communication device, wherein the connection is associated with a
plurality of connection parameters; conveying, by the first sink
communication device to a second sink communication device, the
plurality of connection parameters; receiving, by each of the first
sink communication device and the second sink communication device,
a same broadcast from the source communication device over the
negotiated connection, wherein the broadcast comprises a plurality
of channels; self-determining, by one of the first sink
communication device and the second sink communication device, that
the sink communication device is an intended recipient of a first
channel of the plurality of channels; in response to determining,
by the one of the first sink communication device and the second
sink communication device, that the sink communication device is an
intended recipient of the first channel, decoding, by the one of
the sink communication devices, the first channel but not a second
channel of the plurality of channels; self-determining, by another
of the first sink communication device and the second sink
communication device, that the sink communication device is an
intended recipient of the second channel of the plurality of
channels; in response to determining, by the another of the first
sink communication device and the second sink communication device,
that the sink communication device is an intended recipient of the
second channel, decoding, by the another of the sink communication
devices, the second channel but not the first channel; and playing
out, by each of the first sink communication device and the second
sink communication device, data from the channel decoded by the
sink communication device.
2. The method of claim 1, wherein establishing a connection
comprising discovering, by the source communication device, the
first sink communication device.
3. The method of claim 1, wherein the connection parameters
comprise a channel identifier assigned to the connection by the
source communication device and a channel identifier assigned to
the connection by the first sink communication device.
4. The method of claim 1, wherein the wireless communication system
is a Bluetooth communication system, wherein the source
communication device is a data source, and each of the first sink
communication device and the second sink communication device is a
data sink.
5. The method of claim 1, wherein each of the first channel of the
plurality of channels and the second channel of the plurality of
channels is conveyed over a same time slot of a group of time
slots.
6. The method of claim 1, wherein the first channel of the
plurality of channels is conveyed over a first time slot of a group
of time slots and the second channel of the plurality of channels
is conveyed over a second time slot of the group of time slots.
7. The method of claim 1, wherein the wireless communication system
is a Bluetooth communication system.
8. The method of claim 1, further comprising broadcasting, by the
source communication device, the plurality of channels over the
negotiated connection.
9. A communication device capable of operating as a sink
communication device in a Bluetooth communication system, the
communication device comprising: a radio frequency (RF)
transmitter; an RF receiver; a speaker module; and a processor that
is configured to: negotiate a connection with a source
communication device, wherein the connection is associated with a
plurality of connection parameters; convey, to another sink
communication device, the plurality of connection parameters;
receive, via the RF receiver, a broadcast by the source
communication device over the negotiated connection, wherein the
broadcast comprises a plurality of channels; self-determine whether
the communication device is an intended recipient of a first
channel of the plurality of channels or a second channel of the
plurality of channels; in response to determining that the
communication device is an intended recipient of the first channel,
decode the first channel but not the second channel; in response to
determining that the communication device is an intended recipient
of the second channel, decode the second channel but not the first
channel; and play out, via the speaker module, data from the
channel decoded by the communication device.
10. The communication device of claim 9, wherein the processor is
configured to assign a channel identifier to the connection and
wherein the plurality of connection parameters comprise the
assigned channel identifier and a channel identifier assigned to
the connection by the source communication device.
11. A communication device capable of operating as a sink
communication device in a Bluetooth communication system, the
communication device comprising: a radio frequency (RF) receiver; a
speaker module; and a processor that is configured to: receive,
from another sink communication device, a plurality of connection
parameters associated with a source communication device and a
negotiated connection; receive, via the RF receiver, a broadcast by
the source communication device over the negotiated connection,
wherein the broadcast comprises a plurality of channels;
self-determine whether the communication device is an intended
recipient of a first channel of the plurality of channels or a
second channel of the plurality of channels; in response to
determining that the communication device is an intended recipient
of the first channel, decode the first channel but not the second
channel; in response to determining that the communication device
is an intended recipient of the second channel, decode the second
channel but not the first channel; and play out, via the speaker
module, data from the channel decoded by the communication
device.
12. The communication device of claim 11, wherein the plurality of
connection parameters comprise a channel identifier assigned to the
connection by the another sink communication device and a channel
identifier assigned to the connection by the source communication
device.
13. An apparatus for receiving data in a short-range wireless
communication system, the apparatus comprising: a first sink
communication device; a second sink communication device; and
wherein the first sink communication device negotiates a connection
with a source communication device, which connection is associated
with a plurality of connection parameters, wherein the first sink
communication device conveys the plurality of connection parameters
to the second sink communication device, wherein each of the first
sink communication device and the second sink communication device
receives a same broadcast from the source communication device over
the negotiated connection, wherein the broadcast comprises a
plurality of channels, wherein one of the first sink communication
device and the second sink communication device self-determines
that it is an intended recipient of a first channel of the
plurality of channels and decodes the first channel but not a
second channel of the plurality of channels, wherein another of the
first sink communication device and the second sink communication
device self-determines that it is an intended recipient of the
second channel of the plurality of channels and decodes the second
channel but not the first channel, and wherein each of the first
sink communication device and the second sink communication device
plays out data from the channel decoded by that sink communication
device.
14. The apparatus of claim 13, wherein establishing a connection
comprises discovering, by the source communication device, the
first sink communication device.
15. The apparatus of claim 13, wherein the connection parameters
comprise a channel identifier assigned to the connection by the
source communication device and a channel identifier assigned to
the connection by the first sink communication device.
16. The apparatus of claim 13, wherein the wireless communication
system is a Bluetooth communication system, wherein the source
communication device is a data source, and each of the first sink
communication device and the second sink communication device is a
data sink.
17. The apparatus of claim 13, wherein each of the first channel of
the plurality of channels and the second channel of the plurality
of channels is conveyed by the source communication device over a
same time slot of a group of time slots.
18. The apparatus of claim 13, wherein the first channel of the
plurality of channels is conveyed over a first time slot of a group
of time slots and the second channel of the plurality of channels
is conveyed by the source communication device over a second time
slot of the group of time slots.
19. The apparatus of claim 13, wherein the wireless communication
system is a Bluetooth communication system.
20. The apparatus of claim 19, wherein the apparatus comprises a
Bluetooth headphone.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to short-range
wireless communication systems, such as Bluetooth and Wireless
Local Area Network communication systems, and in particular to
wireless distribution of data to multiple sink communication
devices in a short-range wireless communication system
BACKGROUND OF THE INVENTION
[0002] With the advent of wireless communications, short range
wireless systems have been developed that allow an audio source,
such as a Bluetooth-enabled cellular telephone or music player, to
wirelessly transmit music to multiple audio sinks, such as desktop
speakers or speakers of a Bluetooth headset. However, such speakers
typically require a wired connection between the left and right
speakers, which limits the industrial design of a system and limits
the comfort of a headset. In addition, in surround sound systems
that may employ up to five or more speakers, speaker wires must be
run from the audio source to each speaker, which can be
inconvenient and unsightly.
[0003] One proposed solution to eliminate such speaker wiring is to
use a daisy chain architecture, wherein an audio source, or
transmitter, conveys media content to a single speaker of multiple
speakers. This speaker, also known as a `master speaker,` then
wireless conveys the signal to a second speaker, that is, a `slave
speaker,` which in turn then may convey the signal to a third
speaker, that is, a second `slave speaker,` and so on. However,
this daisy chain solution introduces a latency issue between
speakers that requires tuning during system design and set up. In
addition, the daisy chain solution creates synchronization problems
when media is being watched on the audio source, for example, a
cell phone, while the audio is wirelessly transferred to the
speakers. Another proposed solution is to include multiple radios
in the audio source, that is, one for each speaker, so that the
audio content intended for the speakers may be transmitted
simultaneously to each speaker. However, this is a cumbersome and
expensive solution to the problem.
[0004] Therefore a need exists for a method and an apparatus for
wirelessly transmitting a same stereo content to multiple speakers
and separating the content at the speakers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a block diagram of a Bluetooth communication
system in accordance with an embodiment of the present
invention.
[0006] FIG. 2 is a block diagram of a transmitting communication
system of the communication system of FIG. 1 in accordance with an
embodiment of the present invention.
[0007] FIG. 3 is a block diagram of a receiving communication
system of the communication system of FIG. 1 communication system
in accordance with an embodiment of the present invention.
[0008] FIG. 4 is a block diagram illustrating exemplary protocol
stacks of the communication devices of the communication system of
FIG. 1 in accordance with an embodiment of the present
invention.
[0009] FIG. 5A is a logic flow diagram illustrating a distribution
of user data from a transmitting communication device to multiple
sink communication devices by the communication system of FIG. 1 in
accordance with various embodiments of the present invention.
[0010] FIG. 5B is a continuation of the logic flow diagram of FIG.
5A illustrating a distribution of user data from a transmitting
communication device to multiple sink communication devices by the
communication system of FIG. 1 in accordance with various
embodiments of the present invention.
[0011] One of ordinary skill in the art will appreciate that
elements in the figures are illustrated for simplicity and clarity
and have not necessarily been drawn to scale. For example, the
dimensions of some of the elements in the figures may be
exaggerated relative to other elements to help improve
understanding of various embodiments of the present invention.
Also, common and well-understood elements that are useful or
necessary in a commercially feasible embodiment are often not
depicted in order to facilitate a less obstructed view of these
various embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0012] To address the need for a method and an apparatus for
wirelessly transmitting a same stereo content to multiple speakers
and separating the content at the speakers, a short-range
communication system, such as a Bluetooth communication system, is
provided that provides for a source communication device to
multiplex data packets that are intended for different sink
communication devices of multiple sink communication devices into a
single stream that is broadcast to all of the multiple sink
communication devices, and for each of the multiple sink
communication devices to decode only the data packets intended for
that sink communication device. Further, the communication system
provides for a first sink communication device of the multiple sink
communication devices to negotiate connection parameters associated
the broadcast and to convey the negotiated connection parameters to
a second sink communication device of the multiple sink
communication devices, as opposed to each sink communication device
setting up its own connection with the source communication
device.
[0013] Generally, an embodiment of the present invention
encompasses a method for distributing data in a short-range
wireless communication system. The method includes negotiating, by
a first sink communication device, a connection with a source
communication device, wherein the connection is associated with
multiple connection parameters, and conveying, by the first sink
communication device to a second sink communication device, the
multiple connection parameters. The method further includes
receiving, by each of the first sink communication device and the
second sink communication device, a same broadcast from the source
communication device over the negotiated connection, wherein the
broadcast comprises multiple channels, self-determining, by one of
the first sink communication device and the second sink
communication device, that the sink communication device is an
intended recipient of a first channel of the multiple channels, and
in response to determining, by the one of the first sink
communication device and the second sink communication device, that
the sink communication device is an intended recipient of the first
channel, decoding, by the one of the sink communication devices,
the first channel but not a second channel of the multiple
channels. In addition, the method includes self-determining, by
another of the first sink communication device and the second sink
communication device, that the sink communication device is an
intended recipient of the second channel, in response to
determining, by the another of the first sink communication device
and the second sink communication device, that the sink
communication device is an intended recipient of the second
channel, decoding, by the another of the sink communication
devices, the second channel but not the first channel, and playing
out, by each of the first sink communication device and the second
sink communication device, data from the channel decoded by the
sink communication device.
[0014] Another embodiment of the present invention encompasses a
communication device capable of operating as a sink communication
in a Bluetooth communication system, the communication device
comprising a radio frequency (RF) transmitter, an RF receiver, a
speaker module, and a processor. The processor is configured to
negotiate a connection with a source communication device, wherein
the connection is associated with multiple connection parameters,
convey, to another sink communication device, the multiple
connection parameters, receive, via the RF receiver, a broadcast by
the source communication device over the negotiated connection,
wherein the broadcast comprises multiple channels, self-determine
whether the communication device is an intended recipient of a
first channel of the multiple channels or a second channel of the
multiple channels, in response to determining that the
communication device is an intended recipient of the first channel,
decode the first channel but not the second channel, in response to
determining that the communication device is an intended recipient
of the second channel, decode the second channel but not the first
channel, and play out, via the speaker module, data from the
channel decoded by the communication device.
[0015] Still another embodiment of the present invention
encompasses a communication device capable of operating as a sink
communication in a Bluetooth communication system, the
communication device comprising an RF receiver, a speaker module,
and a processor. The processor is configured to receive, from
another sink communication device, multiple connection parameters
associated with a source communication device and a negotiated
connection, receive, via the RF receiver, a broadcast by the source
communication device over the negotiated connection, wherein the
broadcast comprises a plurality of channels, self-determine whether
the communication device is an intended recipient of a first
channel of the multiple channels or a second channel of the
multiple channels, in response to determining that the
communication device is an intended recipient of the first channel,
decode the first channel but not the second channel, in response to
determining that the communication device is an intended recipient
of the second channel, decode the second channel but not the first
channel, and play out, via the speaker module, data from the
channel decoded by the communication device.
[0016] Yet another embodiment of the present invention encompasses
an apparatus for receiving data in a short-range wireless
communication system. The apparatus comprises a first sink
communication device and a second sink communication device,
wherein the first sink communication device negotiates a connection
with a source communication device, which connection is associated
with multiple connection parameters, wherein the first sink
communication device conveys the multiple connection parameters to
the second sink communication device, wherein each of the first
sink communication device and the second sink communication device
receives a same broadcast from the source communication device over
the negotiated connection, wherein the broadcast comprises multiple
channels, wherein one of the first sink communication device and
the second sink communication device self-determines that it is an
intended recipient of a first channel of the multiple channels and
decodes the first channel but not a second channel of the multiple
channels, wherein another of the first sink communication device
and the second sink communication device self-determines that it is
an intended recipient of the second channel of the multiple
channels and decodes the second channel but not the first channel,
and wherein each of the first sink communication device and the
second sink communication device plays out data from the channel
decoded by that sink communication device.
[0017] The present invention may be more fully described with
reference to FIGS. 1-5B. FIG. 1 is a block diagram of a short-range
wireless communication system 100 in accordance with an embodiment
of the present invention. Communication system 100 includes
multiple wireless communication devices 102, 104, 106 (three
shown). A first communication device 102 of the multiple
communication devices 102, 104, 106 functions as a data source in
communication system 100 and may be referred to herein as a source
transmitting communication device, a transmitting communication
device, or a stereo transmitter. Source communication device 102
may be, for example, a Bluetooth-enabled mobile station, such as a
cell phone, a smartphone, a wireless music player, such as an MP3
player, or a laptop computer equipped for Bluetooth wireless
communications, or may be a desktop computer equipped for Bluetooth
wireless communications. Other communication devices of the
multiple communication devices 102, 104, 106, such as a
communication devices 104 and 106, reside within a listening area
covered by source communication device 102 and function as a data
sink in communication system 100, and may be referred to herein as
a sink communication device, a receiving communication device, or
an audio speaker. For example, each of the multiple sink
communication devices 104, 106 may be a Bluetooth-enabled stereo
loudspeaker or a speaker of a Bluetooth-enabled headphone. While
two sink communication devices are depicted herein, one of ordinary
skill in the art realizes that communication system 100 may include
various numbers of sink communication devices, for example, four or
five sink communication devices as in a surround sound wireless
audio system, and two sink communication devices are used herein
merely for the purpose of illustrating the principles of the
present invention.
[0018] Source communication device 102 communicates with the
multiple sink communication devices 104, 106 via a radio link 110.
Radio link 110 comprises a downlink 112 and an uplink 114 that each
comprises multiple physical channels and logical channels. For
example, each of downlink 112 and uplink 114 of radio link 110
includes one or more control channels, and downlink 112 further
includes one or more user data channels. Sink communication devices
104, 106 may communicate with each other via a bi-directional radio
link 120 that comprises one or more physical channels and one or
more logical communication channels, including one or more control
channels, and/or sink communication devices 104, 106 may
communicate with each other via a wireline link 122.
[0019] FIG. 2 is a block diagram of source communication device 102
in accordance with an embodiment of the present invention. Source
communication device 102 includes a processor 202, such as one or
more microprocessors, microcontrollers, digital signal processors
(DSPs), combinations thereof or such other devices known to those
having ordinary skill in the art, which processor is configured to
execute the functions described herein as being executed by the
transmitting device. Communication device 102 further includes an
at least one memory device 204 that may comprise random access
memory (RAM), dynamic random access memory (DRAM), and/or read only
memory (ROM) or equivalents thereof, that maintain data and
programs that may be executed by the associated processor and that
allow the transmitting device to perform all functions necessary to
operate in communication system 100. The at least one memory device
204 further maintains Bluetooth profiles of the communication
device as known in the art. Communication device 102 also includes
a radio frequency (RF) receiver 206 and an RF transmitter 208 in
communication with processor 202 and for receiving RF signals from,
and transmitting RF signals to, sink communication devices, such as
communication devices 104 and 106, over radio link 110.
[0020] FIG. 3 is a block diagram of a sink communication device
300, such as communication devices 104, 106, in accordance with an
embodiment of the present invention. Sink communication device 300
includes a processor 302, such as one or more microprocessors,
microcontrollers, digital signal processors (DSPs), combinations
thereof or such other devices known to those having ordinary skill
in the art, which processor is configured to execute the functions
described herein as being executed by the transmitting device. Sink
communication device 300 further includes an at least one memory
device 304 that may comprise random access memory (RAM), dynamic
random access memory (DRAM), and/or read only memory (ROM) or
equivalents thereof, that maintain data and programs that may be
executed by the associated processor and that allow the
transmitting device to perform all functions necessary to operate
in communication system 100. At least one memory device 304 further
maintains Bluetooth profiles of the sink communication device as
known in the art. At least one memory device 304 further includes a
position determination module 314 that, when executed by processor
302, determines a position of the sink communication device
relative to another sink communication device.
[0021] Communication device 300 further includes an RF receiver 306
and an RF transmitter 308 in communication with processor 302 and a
speaker module 310 in communication with the processor and with
receiver 306. RF receiver 306 and RF transmitter 308 provide for
receiving RF signals from, and transmitting RF signals to, another
communication device, such as source communication device 102 via
radio link 110 and/or another sink communication device 104, 106
via radio link 120. Speaker module 310 includes an input (not
shown) and an output (not shown), wherein the input receives an
audio signal that then is amplified and output to a user at the
output of the speaker as known in the art. Communication device 300
may further include a wireline interface module 312 for interfacing
with another communication device, such as another sink
communication device, via a wireline connection.
[0022] In order for source communication device 102 to engage in a
communication session with sink communication devices 104, 106,
each communication device 102, 104, 106 operates in accordance with
known telecommunications standards. Preferably, communication
system 100 is a Bluetooth communication system that operates in
accordance with the Bluetooth A2DP (Advanced Audio Distribution
Profile) standards, wherein a physical channel, such as the
channels of radio links 110 and 120, comprises one or more time
slots of a group of time slots, which group of time slots are
frequency hopped over multiple frequencies of a given frequency
bandwidth. To ensure compatibility, radio system parameters and
communication session procedures are specified by the standards,
including communication session set up steps that are executed by
the source and sink communication devices. However, one of ordinary
skill in the art realizes that communication system 100 may be any
wireless communication system that provides short-range radio
links, such as other Bluetooth communication systems or a Wireless
Local Area Network (WLAN) communication system that operates in
accordance with the IEEE (Institute of Electrical and Electronics
Engineers) 802.xx standards, for example, the 802.11 standard.
[0023] Referring now to FIG. 4, exemplary protocol stacks of the
communication devices 102, 104, 106 of communication system 100 are
depicted in accordance with an embodiment of the present invention.
Preferably, communication system 100 is a Bluetooth communication
system that implements well-known Bluetooth protocol stacks. For
example, a top layer, or Application Layer, of each of
communication devices 102, 104, and 106 may include an application
audio source that sources user data for transmission to a sink
communication device and that processes the received user data for
output to a user at a sink communication device. A next layer down
may comprise a Service Layer that includes an Audio/Video
Distribution Transport Protocol layer (AVDTP) 404, 424 and a
Service Discovery Protocol layer (SDP) 406, 426. AVDTP is a
transport protocol based on the Real Time Protocol (RTP) and
applies point-to-point signaling between two communication devices
over an L2CAP channel, including exchanges of SDP messages to
discover the Bluetooth attributes of another communication device,
Quality of Service (QoS) and transport status reporting, and data
stream set-up, reconfiguration, and tear down signaling.
[0024] A next layer down from the Service Layer may comprise a Link
Layer that includes a Link Manager Protocol layer (LMP) 408, 428
and a Layer Logical Link Control and Adaption Protocol layer
(L2CAP) 410, 430. The LMP is responsible for the creation and
management of logical links between devices and logical transports
between devices, encryption on the logical transports, and control
of physical link transmit power and QoS settings. The L2CAP
supports transmission and reception of data packets by higher layer
protocols and supports packet segmentation and reassembly, exchange
of QoS information, and per-channel flow control and
retransmissions. For example, the L2CAP provides for resource
management including segmentation of higher layer service data
units (SDUs) into smaller protocol data units (PDUs), fragmentation
of the PDUs into data packets for submission to the Baseband Layer
and transmission over an air interface, and buffer management to
ensure availability for channels and a given Quality of Service
(QoS). The L2CAP further may provide error detection and
retransmission of L2CAP PDUs. The L2CAP also provides logical
channels, and each endpoint of a logical channel is defined by a
channel identifier (CID). In Bluetooth, each communication device
can assign CIDs independent of assignments made by other
communication devices.
[0025] A next layer down from the Link Layer may comprise a
Baseband Layer that includes a Baseband Manager 412, 432 and a Link
Controller 414, 434. The Baseband Manager includes a scheduling
function that negotiates access to, and grants time on, the
physical channels. The Link Controller is responsible for
communication of flow control, acknowledgments, and retransmission
request signals. A bottom layer may comprise a Physical Layer that
includes RF functionality 416, 436 responsible for transmitting and
receiving packets on the physical channels. The RF functionality
transforms a stream of data received from the Baseband Layer to a
format for transmission over a physical channel and transforms data
received from the physical channel to a format appropriate for the
Baseband Layer.
[0026] Preferably, each of the Application Layer, Service Layer,
Link Layer, and Baseband Layer is implemented by the processor 202,
302 of a communication device 102, 104, 106 based on programs and
instructions maintained in the corresponding at least one memory
device 204, 304, of the communication device. Additionally, the RF
functionality preferably is implemented by the transmitter/receiver
of the communication device, whichever is appropriate.
[0027] In order to distribute user data to the multiple sink
communication devices 104, 106, for example, for source
communication device 102 to broadcast audio data packets to the
multiple sink communication devices 104, 106, communication system
100 provides for source communication device 102 to multiplex data
packets intended for different sink communication devices into a
single stream that is broadcast to all of the multiple sink
communication devices 104, 106, and for each of the multiple sink
communication devices 104, 106 to decode only the data packets
intended for that sink communication device. Thus, communication
system 100 avoids the problems resulting from daisy chaining the
sink communication devices and the expense of including multiple
radios in a source communication device. Further, communication
system 100 provides for a first sink communication device of the
multiple sink communication devices 104, 106 to negotiate
connection parameters associated the broadcast and to convey the
negotiated connection parameters to a second sink communication
device of the multiple sink communication devices, as opposed to
each sink communication device setting up its own connection with
the source communication device.
[0028] Referring now to FIGS. 5A and 5B, a logic flow diagram 500
is provided that illustrates a distribution of user data from
source communication device 102 to each of the multiple sink
communication devices 104, 106 of communication system 100 in
accordance with various embodiments of the present invention. Logic
flow diagram 500 begins (502) when source communication device 102
discovers (504) a first sink communication device, such as sink
communication device 104, of the multiple sink communication
devices 104, 106, preferably in accordance with known Bluetooth
inquiry procedures. For example, source communication device 102
may broadcast an inquiry packet via of radio link 110. In response
to receiving the inquiry packet, sink communication device 104
transmits an inquiry reply back to the source communication device
via a control channel of uplink 114 of radio link 110.
[0029] In response to receiving the inquiry reply, source
communication device 102 authenticates (506) sink communication
device 104 and negotiates (508) a connection with first sink
communication device 104 for a streaming of user data over downlink
112 of radio link 110 in accordance with known Bluetooth
techniques. For example, source communication device 102 may convey
a page sequence to first sink communication device 104. In response
to receiving the page sequence, first sink communication device 104
transmits a page response sequence back to the source communication
device. In response to receiving the page response sequence, source
communication device 102 and first sink communication device 104
then negotiate, and store in the corresponding at least one memory
device 204, 304 of the communication device, connection parameters
associated with a connection for streaming stereo data packets,
that is, for transmitting a first set of data packets intended for
right audio speaker and a second set of data packets intended for a
left audio speaker.
[0030] For example, the connection parameters may include
information identifying logical and physical channels that will be
used to broadcast the stream of user data, for example, identifying
a first logical channel that will include data packets intended for
a right audio speaker and a second logical channel that will
include data packets intended for a left audio speaker, identifying
a physical channel, that is, a time slot, over which the logical
channels will be multiplexed or identifying a first physical
channel, such as a first time slot in a group of time slots, that
will be used to broadcast data packets intended for a right audio
speaker and a second physical channel, such as a second time slot
in the group of time slots, that will be used to broadcast data
packets intended for a left audio speaker. For example, such
identifiers may include at least one CID assigned by source
communication device 102 to the connection (for example, source
communication device 102 may assign a CID to each logical channel
of multiple logical channels to be included in a broadcast), a CID
assigned by sink communication device 104 to the connection, and
time slot and hopping pattern information with respect to the
physical channel(s). The connection parameters further may include
device identifiers, such as a Bluetooth Device Address (BD_ADDR)
for each of the source communication device and the sink
communication device and an authentication key, that is, a link
key.
[0031] In response to negotiating the connection parameters with
source communication device 102, first sink communication device
104 then performs a handshake with a second sink communication
device of the multiple sink communication devices 104, 106, that
is, sink communication device 106, preferably via the Link Manager
Protocol layer of each device. That is, first sink communication
device 104 then conveys (514) the connection parameters to second
sink communication device 106. For example, in another embodiment
of the present invention, each of the multiple sink communication
devices 104, 106 may be pre-programmed as to which of the two sink
communication devices is to be a `master` sink communication
device, that is, a sink communication device that sets up a
connection with source communication device 102, and which of the
two sink communication devices is to be a `slave` sink
communication device, that is, a sink communication device that
receives connection parameters from the `master` device. In another
embodiment of the present invention, the determination of which of
the two sink communication devices 104, 106 is to be the `master`
sink communication device and which of the two sink communication
devices is to be the `slave` sink communication device may be
negotiated between the two devices, for example, the `slave` device
may be whichever device first detects a page sequence from the
other device in the event that they communicate with each other
over a radio link.
[0032] As part of the handshake, first sink communication device
104 also may inform second sink communication device 106 whether
the first sink communication device is a left device or right
device, such as a left or right audio speaker, and that the second
sink communication device is the other, that is, a right device (if
the first sink communication device is a left device) or a left
device (if the first sink communication device is a right
device).
[0033] In various embodiments of the present invention, first sink
communication device 104 may convey the connection parameters, and
any left/right device designation, to second sink communication
device 106 over wireline 122 or over a control channel in radio
link 120 that is pre-programmed into the at least one memory
devices 304 of each of the sink communication devices 104, 106.
That is, in the latter instance, when the multiple sink
communication devices 104, 106 power up, they may discover (510)
each other via radio link 120 and in accordance with the inquiry
procedure described above. Upon discovering each other, each of the
multiple sink communication devices 104, 106 may monitor a
pre-programmed control channel in radio link 120, that is, a
control channel that is pre-programmed into the at least one memory
device 304 of each sink communication device 104, 106, for control
information, such as the connection parameters, from the other sink
communication device. First sink communication device 104 then
conveys to second communication device 106 over the monitored
control channel in radio link 120 the information identifying a
channel that will be used for the exchange of user data,
communication device identifiers associated with the connection,
such as the Bluetooth Device Addresses for each of source
communication device 102 and first sink communication device 104,
and the CIDs assigned by each of the source communication device
and the first sink communication device to the connection, and any
authentication keys and encryption keys that were exchanged. In
effect and to a limited extent, the first sink communication device
thus creates a clone of itself in the second sink communication
device.
[0034] Second sink communication device 106 then stores the
received connection parameters, and any received indication as to
whether the second sink communication device is a left device or a
right device, in the at least one memory device 304 of the
communication device. In addition to, and when conveying the
connection parameters over the pre-programmed control channel in
radio link 120, one or both of sink communication devices 104, 106
also may authenticate (512) the other sink communication device via
radio link 120. In one such embodiment of the present invention,
the sink communication devices 104, 106 may exchange authentication
information over the pre-programmed control channel and
authenticate each other. In yet another embodiment of the present
invention, only the `master` sink communication device may
authenticate the `slave` sink communication device while the
`slave` device need not authenticate the `master` device.
[0035] Subsequent to negotiating the connection with first sink
communication device 104, source communication device 102
broadcasts (516), over the negotiated connection and to all of the
multiple sink communication devices 104, 106, a stream of user data
packets comprising data packets intended for a first, or left,
device, which data packets are conveyed over a first, or left,
logical channel, and data packets intended for a second, or right,
device, which data packets are conveyed over a second, or right,
logical channel. For example, source communication device 102 may
multiplex the first/left logical channel and the second/right
logical channel over a same time slot, alternating transmissions of
the two channels, or may multiplex the first/left logical channel
and the second/right logical channel by transmitting each in a
separate time slot of a group of time slots, which group of time
slots are frequency hopped together.
[0036] Each sink communication device 104, 106 receives (518) the
same broadcast of the stereo data packets, that is, receives the
broadcast of both the left and right logical channels. Position
determination module 314 of each sink communication device
determines (520) whether the device comprises a left device or a
right device and, in response to determining, by each sink
communication device 104, 106, whether the sink communication
device comprises the left device or the right device, the sink
communication device decodes (522) the corresponding channel. That
is, in response to a sink communication device, such as sink
communication device 104, determining that it is a left device, the
sink communication device then decodes the corresponding left
logical channel but not the right logical channel. Similarly, in
response to a sink communication device, such as sink communication
device 106, determining that it is a right device, the sink
communication device then decodes the corresponding right logical
channel but not the left logical channel. Each sink communication
device 104, 106 then processes the decoded data packets in
accordance with well-known techniques and plays out (524) the
decoded and processed data packets via the corresponding speaker
module 310 of the communication device, and logic flow 500 then
ends (526).
[0037] For example, in one embodiment of the present invention as
described above, when the first sink communication device conveys
connection information to the second sink communication device, the
first sink communication device may designate itself as one of the
right or left device and inform the second sink communication
device that the second device is, correspondingly, the other
device, that is, the left or right device. Each of the two sink
communication devices stores this left/right designation in its
corresponding at least one memory device 304. When a broadcast is
received from source communication device 102, position
determination module 314 of each sink communication device
determines whether the device is the right or left device based on
the stored left/right designation.
[0038] By way of another example, in another embodiment of the
present invention, each of the first and second sink communication
devices 104, 106, may be pre-programmed, in at least one memory
device 304 of the sink communication device, with a right device
designation or a left device designation. When the broadcast is
received from source communication device 102, position
determination module 314 of each sink communication device
determines whether the device is the right or left device based on
the stored left/right designation.
[0039] By way of yet another example, in yet another embodiment of
the present invention and in the event that each of the first and
second sink communication devices 104, 106 are part of a Bluetooth
headphone, each of the first and second sink communication devices
may determine whether it is a right device or a left device based
on an orientation of the device with respect to the headphone. That
is, suppose that a default position for each of the speakers of the
headphone is that the speakers face directly at each other, such
that a vector normal to each speaker points directly at the other
speaker. When the headphone is placed on a user's head, typically a
right speaker, that is, a speaker on a right side of the user's
head, is rotated to the left of the default position, that is, a
vector normal to the right speaker is angled to the left of the
position of the speaker's normal vector when the speaker is in the
default position. Similarly, a left speaker, that is, a speaker on
a left side of the user's head, is rotated to the right of the
default position, that is, a vector normal to the left speaker is
angled to the right of the position of the speaker's normal vector
when the speaker is in the default position. Accordingly, each of
the first and second sink communication devices 104, 106 may
determine whether it is a right device or a left device based on a
orientation, that is, a rotation, of the device relative to the
device's default position. For example, such a determination may be
implemented by including a switching module comprising one or more
switches (not shown) in each sink communication device, which
switching module detects whether the device is rotated to the left
(and accordingly is a right device) or the right (and accordingly
is a left device) of the default position and stores the determined
position in a corresponding at least one memory device 304.
However, one of ordinary skill in the art can think of many other
schemes whereby a device can determine whether it is rotated to the
left or the right of a default position, and any such scheme may be
used herein without departing from the spirit and scope of the
present invention. When a broadcast is received from source
communication device 102, position determination module 314 of each
sink communication device determines whether the device is the
right or left device based on the stored left/right position. By
way of still another example, in still another embodiment of the
present invention, each sink communication device 104, 106, may
determine whether it is a left device or a right device based on a
direction of arrival of the broadcast signal broadcast by source
communication device and a direction of arrival of a RF control
signal received from the other sink source communication device.
For example, based on the signaling exchanged between sink
communication devices 104, 106 each sink communication device 104,
106 may determine a direction of arrival of the signals from the
other sink communication device in accordance with known direction
of arrival determination techniques. Further, based on the
broadcast received from source communication device 102, each sink
communication device 104, 106 may determine a direction of arrival
of the broadcast, again in accordance with known direction of
arrival determination techniques. Based on the determined direction
of arrival of the signals from the other sink communication device
and the determined direction of arrival of the broadcast, each the
position determination module 314 of sink communication device may
determine whether it is the right device, such as a right audio
speaker, or a left device, such as a left audio speaker. For
example, when the sink communication devices are audio speakers of
a Bluetooth headphone and the direction of arrival of the signals
from one such sink communication device is to the right of the
direction of arrival of the broadcast, then such sink communication
device may determine that it is the left speaker, and visa versa.
On the other hand, when the sink communication devices are
freestanding speakers, and the direction of arrival of the signals
from one such sink communication device is to the right of the
direction of arrival of the broadcast, then such sink communication
device may determine that it is the right speaker, and visa versa.
Based on the determination of whether the sink communication device
is a left device or a right device, the sink communication device
then decodes the channel corresponding to a left device or a right
device, whichever is appropriate.
[0040] By multiplexing data packets that are intended for different
sink communication devices, for example, a left sink communication
device and a right sink communication device, of multiple sink
communication devices into a single stream that a source
communication device broadcasts to all of the multiple sink
communication devices, communication system 100 avoids the problems
of the prior art resulting from daisy chaining the sink
communication devices and the expense of including multiple radios
in a source communication device. Further, by communication system
100 providing for a first sink communication device of multiple
sink communication devices to negotiate connection parameters
associated the broadcast and to convey the negotiated connection
parameters to a second sink communication device of the multiple
sink communication devices, communication system 100 provides a
more efficient data distribution system than where each sink
communication device sets up its own connection with the source
communication device, or where a source communication device
transmits data packets that are intended for different sink
communication devices only to a first, for example, a left, sink
communication device, which first sink communication device then
forwards data packets intended for the second communication device,
for example, a right device, to that device.
[0041] Additionally, communication system 100 provides for each
sink communication device to self-determine which channel, of
multiple channels broadcast by a source communication device, to
decode. Such a determination may be made as a result of a prior
consultation with other sink communication devices of the multiple
sink communication devices, or the determination may be completely
self-contained. In either event, only a single sink communication
device of the multiple sink communication devices need negotiate,
with the source communication device, a connection for the
broadcast. Furthermore, by each sink communication device
self-determining which channel to decode, when there are two sink
communication devices the devices should not end up decoding the
same channel, such as a left channel, and failing to decode the
other channel, that is, the right channel. Furthermore, by
providing for each sink communication devices to self-determine a
channel to decode, communication system 100 is easily expandable to
additional sink communication devices. Unless otherwise specified
herein, the functionality described herein as being performed by
source communication device 102 and sink communication devices 104
and 106 is implemented with or in software programs and
instructions stored in the respective at least one memory device
204, 304 associated with the transmitting and sink communication
devices and executed by the processor 202, 302 associated with the
transmitting and sink communication devices. However, one of
ordinary skill in the art realizes that the embodiments of the
present invention alternatively may be implemented in hardware, for
example, integrated circuits (ICs), application specific integrated
circuits (ASICs), and the like, such as ASICs implemented in one or
more of the transmitting and sink communication devices. Based on
the present disclosure, one skilled in the art will be readily
capable of producing and implementing such software and/or hardware
without undo experimentation.
[0042] In the foregoing specification, specific embodiments have
been described. However, one of ordinary skill in the art
appreciates that various modifications and changes can be made
without departing from the scope of the invention as set forth in
the claims below. Accordingly, the specification and figures are to
be regarded in an illustrative rather than a restrictive sense, and
all such modifications are intended to be included within the scope
of present teachings.
[0043] The benefits, advantages, solutions to problems, and any
element(s) that may cause any benefit, advantage, or solution to
occur or become more pronounced are not to be construed as a
critical, required, or essential features or elements of any or all
the claims. The invention is defined solely by the appended claims
including any amendments made during the pendency of this
application and all equivalents of those claims as issued.
[0044] Moreover in this document, relational terms such as first
and second, top and bottom, and the like may be used solely to
distinguish one entity or action from another entity or action
without necessarily requiring or implying any actual such
relationship or order between such entities or actions. The terms
"comprises," "comprising," "has", "having," "includes",
"including," "contains", "containing" or any other variation
thereof, are intended to cover a non-exclusive inclusion, such that
a process, method, article, or apparatus that comprises, has,
includes, contains a list of elements does not include only those
elements but may include other elements not expressly listed or
inherent to such process, method, article, or apparatus. An element
proceeded by "comprises . . . a", "has . . . a", "includes . . .
a", "contains . . . a" does not without more constraints, preclude
the existence of additional identical elements in the process,
method, article, or apparatus that comprises, has, includes,
contains the element. The terms "a" and "an" are defined as one or
more unless explicitly stated otherwise herein. The terms
"substantially," "essentially," "approximately," "about," or any
other version thereof, are defined as being close to as understood
by one of ordinary skill in the art, and in one non-limiting
embodiment the term is defined to be within 10%, in another
embodiment within 5%, in another embodiment within 1% and in
another embodiment within 0.5%. The term "coupled" as used herein
is defined as connected, although not necessarily directly and not
necessarily mechanically. A device or structure that is
"configured" in a certain way is configured in at least that way,
but may also be configured in ways that are not listed.
[0045] The Abstract of the Disclosure is provided to allow the
reader to quickly ascertain the nature of the technical disclosure.
It is submitted with the understanding that it will not be used to
interpret or limit the scope or meaning of the claims. In addition,
in the foregoing Detailed Description, it can be seen that various
features are grouped together in various embodiments for the
purpose of streamlining the disclosure. This method of disclosure
is not to be interpreted as reflecting an intention that the
claimed embodiments require more features than are expressly
recited in each claim. Rather, as the following claims reflect,
inventive subject matter lies in less than all features of a single
disclosed embodiment. Thus the following claims are hereby
incorporated into the Detailed Description, with each claim
standing on its own as a separately claimed subject matter.
* * * * *