U.S. patent application number 13/088986 was filed with the patent office on 2012-07-12 for wireless communication techniques.
This patent application is currently assigned to MICROSOFT CORPORATION. Invention is credited to Rod G. Fleck, Peter S. Hoang, Jedd A. Perry.
Application Number | 20120178380 13/088986 |
Document ID | / |
Family ID | 46455633 |
Filed Date | 2012-07-12 |
United States Patent
Application |
20120178380 |
Kind Code |
A1 |
Fleck; Rod G. ; et
al. |
July 12, 2012 |
Wireless Communication Techniques
Abstract
Wireless communication techniques are described. In one or more
implementations, techniques are described that involve active power
control such that a device may bypass use of a power amplifier to
communicate wirelessly. In one or more additional implementations,
wireless communication techniques are described in which multiple
bands may be leveraged to provide wireless communication. In one or
more further implementations, wireless communication techniques are
described in which a frame buffer on a receiving device is
leveraged by a sending device. Yet further, in one or more
implementations wireless communication techniques are described in
which a sending device employs codec adaptation. Still yet further,
in one or more implementations, wireless communication techniques
are described which may be used to change characteristics of a
channel used to communicate data. Yet further again, in one or more
implementations, a receiving device is configured to adjust a
display based on wireless communications received from a plurality
of devices, such as to leverage a display by multiple wireless
sources.
Inventors: |
Fleck; Rod G.; (Bellevue,
WA) ; Perry; Jedd A.; (Monroe, WA) ; Hoang;
Peter S.; (Snoqualmie, WA) |
Assignee: |
MICROSOFT CORPORATION
Redmond
WA
|
Family ID: |
46455633 |
Appl. No.: |
13/088986 |
Filed: |
April 18, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61430639 |
Jan 7, 2011 |
|
|
|
61431312 |
Jan 10, 2011 |
|
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Current U.S.
Class: |
455/69 |
Current CPC
Class: |
H04N 7/0806 20130101;
H04L 5/0007 20130101; H04W 84/12 20130101; H04W 84/18 20130101;
H04L 5/0053 20130101; H04W 52/0274 20130101; Y02D 30/70 20200801;
H04W 52/247 20130101; H04W 52/52 20130101; H04W 52/241
20130101 |
Class at
Publication: |
455/69 |
International
Class: |
H04B 7/00 20060101
H04B007/00 |
Claims
1. A method comprising: detecting by a sending device whether
communications between a receiving device and sending device are
comply with a predefined link quality; responsive to a
determination that the communications do comply with the predefined
link quality bypassing a power amplifier of the sending device to
transmit a wireless communication to be received by the sending
device; and responsive to a determination that the communications
between the receiving device and the sending device do not comply
with the predefined link quality, using the power amplifier of the
sending device to transmit a wireless communication to be received
by the sending device.
2. A method as described in claim 1, wherein the detecting is based
at least in part on an error rate or a scan of the channels during
one or more non-transmit cycles.
3. A method as described in claim 1, wherein the bypassing causes
the power amplifier to be disabled.
4. A method as described in claim 1, wherein the bypassing is
performed to turn off a supply rail to the power amplifier.
5. A method as described in claim 1, wherein the bypassing uses
radio frequency (RF) switches to route a signal to the antenna and
bypass the power amplifier.
6. A method as described in claim 1, wherein the wireless
communication between the sending and receiving device is
configured to communicate over short or medium ranges and is not
configured for telephone communication.
7. A method as described in claim 1, wherein the wireless
communication is configured for compatibility with Wi-Fi.
8. A method as described in claim 1, wherein the wireless
communication is configured for compatibility with one or more
Institute of Electrical and Electronics Engineers (IEEE) standards
for wireless communication.
9. A method comprising: determining by a sending device that a
second frame that is to be transmitted by the sending device to a
receiving device includes at least a portion that is a repeat of a
corresponding portion of a first frame that was transmitted by the
sending device to the receiving device; and responsive to the
determination, causing at least a portion of the first frame, which
matches the portion of the second frame, of the received device to
be repeated for display by the receiving device without
transmitting the portion of the second frame by the sending
device.
10. A method as described in claim 9, wherein the receiving device
employs a buffer that stores a copy of the portion of the first
frame that is to be repeated.
11. A method as described in claim 9, wherein the causing is
performed without transmitting controls signals or frames by the
sending device to the receiving device.
12. A method as described in claim 9, further comprising responsive
to the determination, entering a sleep mode by one or more hardware
devices of the sending device until an update to the first frame is
to be transmitted to the receiving device that includes content
that is not included in the first frame.
13. A method as described in claim 9, further comprising responsive
to the determination, reducing a transmission frame rate of the
sending device to the receiving device.
14. A method as described in claim 9, wherein the sending device
employs one or more extender concepts such that: a video stream is
sent independent of a user interface stream; and updates for a
subsection of a display that include the video stream are
transmittable without sending an update to the user interface
stream.
15. A method as described in claim 14, wherein an audio stream is
sent independent of the video stream and the user interface stream
such that an update to the audio stream is transmittable by the
sending device without sending an update to the user interface
stream or an update to the video stream.
16. A method comprising: receiving two or more streams wirelessly
at a display device from respective two or more computing devices;
and automatically portioning a display area of the display device
such that content from the two or more streams is displayable
concurrently by the display device.
17. A method as described in claim 16, wherein the display device
is configured for use as a three-dimensional display and content
from a first said stream is viewable using a first pair of
three-dimensional viewing glasses but not a second pair of
three-dimensional viewing glasses and content from a second said
stream is viewable using the second pair of three-dimensional
viewing glasses but not the first pair of three-dimensional viewing
glasses.
18. A method as described in claim 16, wherein data communicated
via the two or more streams is formatted by respective said
computing devices based at least on a respective portion via which
the data is to be displayed by the display device.
19. A method as described in claim 18, wherein the reformatting
includes adjusting an aspect ratio or resolution to approximate an
aspect ratio or resolution of the respective portion.
20. A method as described in claim 16, wherein the portioning is
performed such that one or more portions are resizable using
picture-in-picture techniques.
Description
RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C.
.sctn.119(e) to U.S. Provisional Patent Application No. 61/430,639
(Attorney Docket No. 331722.01) filed Jan. 7, 2011 and U.S.
Provisional Patent Application No. 61/431,312 (Attorney Docket No.
332027.01) filed Jan. 10, 2011, the entire disclosure of each of
these applications is hereby incorporated by reference.
BACKGROUND
[0002] The prevalence of wireless communication is ever increasing.
Originally, wireless communication techniques were employed by
computing devices such as traditional desktop computers and laptops
to communicate locally with each other as well as remotely via the
Internet. Use of these techniques was then expanded to a wide
variety of other devices, such as game consoles, input devices
(e.g., keyboard and mouse), printers, and so on.
[0003] As this use expanded, however, traditional techniques that
were employed to perform wireless communication were confronted
with a wide range of difficulties. For example, the sheer
prevalence of these techniques may cause interference between
devices that employed the techniques thereby limiting the
usefulness of the techniques to each of the devices that employ
them. Further, the techniques may consume relatively large amounts
of power to overcome this interference, which may limit usefulness
of the techniques to mobile devices that are powered by a battery
and cause further interference.
SUMMARY
[0004] Wireless communication techniques are described. In one or
more implementations, techniques are described that involve active
power control such that a device may bypass use of a power
amplifier to communicate wirelessly. In one or more additional
implementations, wireless communication techniques are described in
which one or more streams on a receiving device are leveraged by a
sending device, such as through use of a buffer. In one or more
further implementations, a receiving device is configured to adjust
a display based on wireless communications received from a
plurality of devices.
[0005] Yet further, wireless communication techniques are described
in which multiple bands may be leveraged to provide wireless
communication. Yet further again, in one or more implementations
wireless communication techniques are described in which a sending
device may employ codec adaptation. Still yet further, in one or
more implementations, wireless communication techniques are
described which may be used to change characteristics of a channel
used to communicate data.
[0006] This Summary is provided to introduce a selection of
concepts in a simplified form that are further described below in
the Detailed Description. This Summary is not intended to identify
key features or essential features of the claimed subject matter,
nor is it intended to be used as an aid in determining the scope of
the claimed subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The detailed description is described with reference to the
accompanying figures. In the figures, the left-most digit(s) of a
reference number identifies the figure in which the reference
number first appears. The use of the same reference numbers in
different instances in the description and the figures may indicate
similar or identical items.
[0008] FIG. 1 is an illustration of an environment in an example
implementation that is operable to employ short and medium range
wireless communication techniques.
[0009] FIG. 2 depicts a system in an example implementation in
which a computing device of FIG. 1 is configured to bypass and
disable a power amplifier for short range wireless
communication.
[0010] FIG. 3 is a flow diagram depicting a procedure in an example
implementation of wireless communication techniques that relate to
control of a power amplifier to transmit data over different
ranges.
[0011] FIG. 4 depicts a system in an example implementation in
which existence of a buffer and/or use of a data stream on a
receiving device is leveraged by a sending device.
[0012] FIG. 5 is a flow diagram depicting a procedure in an example
implementation of wireless communication techniques that relate to
wireless buffering and stream usage techniques.
[0013] FIG. 6 depicts a system in an example implementation in
which display techniques are employed in a wireless
environment.
[0014] FIG. 7 is a flow diagram depicting a procedure in an example
implementation of wireless communication techniques that relate to
wireless display techniques for content received from a plurality
of devices.
[0015] FIG. 8 illustrates an example system in which dual band
functionality of a wireless device is leveraged to provide wireless
communication that employs both bands.
[0016] FIG. 9 is a flow diagram depicting a procedure in an example
implementation of wireless communication techniques that relate to
communication functionality that leverage a plurality of bands.
[0017] FIG. 10 depicts a system in an example implementation in
which wireless encoding and decoding techniques are employed.
[0018] FIG. 11 is a flow diagram depicting a procedure in an
example implementation of wireless communication techniques that
relate to wireless encoding and decoding techniques.
DETAILED DESCRIPTION
Overview
[0019] The prevalence of devices that employ wireless communication
is ever increasing. Consequently, traditional techniques that were
employed to provide wireless communication may be confronted with
an ever increasing amount of interference between these devices,
which may limit usefulness of the communication techniques.
[0020] Wireless communication techniques are described. In one or
more implementations, techniques are described that involve active
power control such that a device may bypass and disable the power
amplifier to communicate wirelessly. The techniques may be employed
by but are not limited to short and medium range direct and
indirect communication, such as Bluetooth, Wi-Fi (e.g., IEEE
802.11), Wi-Max, and so on. In this way, power consumption by the
device may be lessened in situations in which use of the power
amplifier may be avoided, further discussion of which may be found
in relation to FIGS. 2 and 3.
[0021] In one or more implementations, wireless communication
techniques are described in which one or more frame buffers and/or
streams on a receiving device are leveraged by a sending device.
For example, the sending device may determine that a next frame
matches a frame already sent to a receiving device and may then
hibernate parts of the device that are used to transmit frames
until a "new" frame is to be sent. In this way, power usage and
network interference by the sending device may be decreased,
further discussion of which may be found in relation to FIGS. 4 and
5.
[0022] In one or more implementations, a receiving device is
configured to adjust a display based on wireless communications
received from a plurality of devices. For example, the receiving
device may be configured as a television. The television may
receive wireless communications from a plurality of different
devices, e.g., mobile phones. The television may then portion the
display to display video from each of the devices. Further, the
video sent by the devices may be configured according to how it is
to be displayed by the display device, such as by adjusting a
resolution and/or aspect ratio to match the portion in which the
video is to be displayed. Further discussion of these techniques
may be found in relation to FIGS. 6 and 7.
[0023] In one or more implementations, wireless communication
techniques are described in which multiple bands may be leveraged
to provide wireless communication. For example, a wireless device
may have support for both 2.4 GHz and 5.0 GHz bands. The device may
be configured to employ both bands to communicate with other
devices, such as to employ the 2.4 GHz band to communicate control
information and the 5.0 GHz band to communicate a data payload
simultaneously, further discussion of which may be found in
relation to FIGS. 8 and 9.
[0024] In one or more implementations, depending on the content
type for the specific frame, the codec type may be changed to a
type that is better suited for handling a current information type.
This may be performed by leveraging multiple processing techniques
such as frequency profile, frequency gradients, temporal changes,
edge change detection and other video and image progressing
algorithms. Additionally, this may be performed as part of a
decision tree to select an appropriate compression (e.g., codec)
for use by the video frame, further discussion of which may be
found in relation to FIGS. 10 and 11.
[0025] In one or more implementations, wireless communication
techniques are also described which may be used to change
characteristics of a channel used to communicate data. For example,
the sending device may detect noise and renegotiate with a
receiving device for a new channel, thereby saving power due to the
increased cleanliness of the new channel and less retransmission of
data. Other techniques are also contemplated, such as to
dynamically adjust a compression ratio, an amount of change, change
from one codec to another, beam forming, FEC (Forward Error
Correction) and so on, further discussion of which may be found in
relation to FIGS. 10 and 11.
[0026] In one or more implementations, wireless communication
techniques are described in which a sending device employs codec
adaptation. For example, a sending device may determine whether a
receiving device supports video in a current format. If so, the
sending device may communicate the video without decoding it. If
not, the sending device may transcode the video. In this way, the
sending device may conserve resources that would otherwise be used
to unnecessarily decode the video, further discussion of which may
be found in relation to FIGS. 10 and 11.
[0027] In the following discussion, example environments are
described that may be employed to perform the techniques described
herein. Example procedures are also described, which may be
performed in the example environments and elsewhere. Accordingly,
the example environments are not limited to performance of the
example procedures and the example procedures are not limited to
being performed in the example environments.
[0028] Example Wireless Environment
[0029] FIG. 1 is an illustration of an environment 100 in an
example implementation that is operable to employ the wireless
communication techniques described herein. The illustrated
environment 100 includes an access point 102, a computing device
104, and another computing device 106 that are communicatively
coupled via a wireless network 108.
[0030] The computing devices 104, 106 may be configured in a
variety of ways. For example, the computing devices 104, 106 may be
configured as computers that are capable of communicating over a
wireless network 108, such as a desktop computer, a mobile station,
an entertainment appliance, a tablet, a set-top box communicatively
coupled to a display device, a wireless phone, a game console, a
digital television, and so forth. Thus, the computing devices 104,
106 may range from full resource devices with substantial memory
and processor resources (e.g., personal computers, game consoles)
to a low-resource device with limited memory and/or processing
resources (e.g., traditional set-top boxes, hand-held game
consoles, "dumb" digital televisions having limited
functionality).
[0031] The computing devices 104, 106 may also include an entity
(e.g., software) that causes hardware of the computing devices 104,
106 to perform operations, e.g., processors, functional blocks, and
so on. For example, the computing devices 104, 106 may include a
computer-readable medium that may be configured to maintain
instructions that cause the respective computing device, and more
particularly hardware of the computing devices 104, 106 to perform
operations. Thus, the instructions function to configure the
hardware to perform the operations and in this way result in
transformation of the hardware to perform functions. The
instructions may be provided by the computer-readable medium to the
computing devices 104, 106 through a variety of different
configurations.
[0032] One such configuration of a computer-readable medium is
signal bearing medium and thus is configured to transmit the
instructions (e.g., as a carrier wave) to the hardware of the
computing device, such as via the network 108. The
computer-readable medium may also be configured as a
computer-readable storage medium and thus is not a signal bearing
medium. Examples of a computer-readable storage medium include a
random-access memory (RAM), read-only memory (ROM), an optical
disc, flash memory, hard disk memory, and other memory devices that
may use magnetic, optical, and other techniques to store
instructions and other data.
[0033] Although a single wireless network 108 is illustrated, the
network may assume a wide variety of configurations and may be
configured to include multiple networks, e.g., to support direct
and/or indirect communication, follow different standards, and so
on. The wireless network 108, for instance, may be configured for
short range communication, e.g., communication typically employed
with a distance of 10 meters. For example, the short range
communications may be configured to support direct and/or indirect
communication within a room or between adjacent rooms of a
structure such as a typical user's house.
[0034] The wireless network 108 may also be configured for medium
range communication such as in accordance with Wi-Fi (e.g., IEEE
802.11) for distances of up to approximately 300 meters, WiMAX
(e.g., IEEE 802.16) for distances of up to approximately 1 km, and
so on. These standards allow a variety of different computing
devices (e.g., laptops, phones, games machines, and consumer
electronics devices) to connect to the access point 102 and/or
directly with each other to allow mobile communication of a variety
of content, such as web content, media content, email, messaging,
and a variety of other data types. For example, a majority of mid
to high end mobile communication devices may leverage Wi-Fi to
enable rich browsing, increased functionality for applications, and
data oriented communications. Thus, in each of these examples of
short and medium range communication the wireless network 108 is
not a wireless telephone (e.g., cellular) network that is typically
used for telephone communication, although such implementations are
also contemplated.
[0035] The access point 102 and the computing devices 104, 106 are
each illustrated as including a respective communication module
110, 112, 114. The communication modules 110, 112, 114 are
representative of functionality of the respective device to
communicate over the wireless network 108. For example, the
communication modules 110, 112, 114 may represent functionality
that may be used to encode data for transmission as well as decode
data received by the device in accordance with one or more of the
standards described above. The functionality may also involve
techniques that may be used to manage communication, such as to
negotiate channels, resolve collisions, and so on.
[0036] As previously described, the variety of devices that employ
wireless communication techniques is ever increasing, such as
laptops, digital television, smart phone platforms, optical disc
players, and so on. Some of these devices may also employ a set of
standards (e.g., from the Digital Living Network Alliance) to allow
device discovery and connection, media file browsing, and exchange
of digital media such as photos, music, and videos.
[0037] Accordingly, a variety of different techniques maybe used to
communicate via the wireless network 108. For example,
communication may be performed using the access point 102 such that
the computing device 104 transmits data through the access point
102 for receipt by the computing device 106. Direct communication
between the computing devices 104, 106 may also be supported that
does not involve use of the access point 102 or other device as an
intermediary.
[0038] For instance, direct communication (e.g., Wi-Fi direct) may
be leveraged to avoid costly dual path connections (e.g., up to
access point 102 and down from access point 102) of devices where
principally point-to-point connections may be employed, e.g., when
the computing devices 104, 106 are within range of each other. This
allows data types (e.g., video) to be sent directly from a sending
device (e.g., the computing device 104 illustrated as a smart
phone) directly to a receiving device, e.g., to the computing
device 106 illustrated as a digital television. Thus, the wireless
network 108 may also represent communication that does not involve
the access point 102. In an implementation, the computing device
104 may also communicate with the access point 102 for web based
content, but the data from phone to digital television is not
transferred to the access point 102.
[0039] Additional standards may be employed in the environment 100
which relate to Wi-Fi display. For example, uncompressed standards
(e.g., Wi-Gig) or compressed standards (e.g., 802.11n) may be
followed to transmit display information such as video that may be
displayed by a display device, such as the illustrated digital
television. Wi-Fi display opens up a number of opportunities beyond
traditional media types to web pages, games, messaging, and so on.
It may also be used to allow the source device (e.g., the computing
device 104) to control the target display (e.g., computing device
106) thereby allowing a predictable and consistent user experience.
For instance, the source device (potentially also multiple devices)
may be used to drive each of the pixels on the target device, a
portion of the pixels allotted to the source device, and so on as
further described in the following discussion.
[0040] In the following sections, a number of power consumption and
overall wireless network quality improvement techniques are
discussed. Examples of such techniques include "backing off"
transmit power to a minimum level that is usable to successfully
drive a wireless display device, avoiding use of a common frequency
for wireless display and access point transactions, dynamically
changing codec type and/or parameters, as well as techniques usable
to avoid transmission of redundant data between the devices.
Further discussion of these and other techniques may be found in
relation to the following sections.
[0041] Generally, any of the functions described herein can be
implemented using software, firmware, hardware (e.g., fixed logic
circuitry), manual processing, or a combination of these
implementations. The terms "module" and "functionality" as used
herein generally represent hardware, software, firmware, or a
combination thereof. In the case of a software implementation, the
module, functionality, or logic represents instructions and
hardware that performs operations specified by the hardware, e.g.,
one or more processors, functional blocks, and/or application
specific integrated circuits.
[0042] Power Amplifier Techniques
[0043] FIG. 2 depicts a system 200 in an example implementation in
which a computing device 104 of FIG. 1 is configured to bypass and
disable a power amplifier for wireless communication. The
communication module 112 of the computing device 104 is illustrated
as including a communication manager module 202, a power amplifier
204, an antenna 206, a power supply 208, and a switch 210.
[0044] In the illustrated example, Wi-Fi communications between the
computing device 104 and the access point 102 may occur over a
significant range as the access point 102 may be frequently located
in a different room, different floor in a house, and so on.
Consequently, in order to drive high bandwidth communications in
such a situation, the output power from the accessing device may be
relatively high. However, other situations may also be encountered,
such as when the communicating devices (e.g., the computing device
104 and another computing device 106) are located, in comparison,
at a relatively close range to each other as illustrated. For
example, in wireless display scenarios that involve both direct
communication between the devices and a relatively short distance
(e.g., under five meters), significantly lower power may be used
while still operating at high bandwidths, e.g., at high Quadrature
Amplitude Modulation (QAM) configurations, as would otherwise be
the case when operating across a relatively longer distance.
Therefore reducing the RF footprint of a particular wireless
communication system which will permit greater frequency and/or
channel reuse densities.
[0045] Accordingly, in this example the communication module 112
may adapt to changes in range by measuring wireless link quality
and adjusting power output control on a regular basis, such as a
packet-by-packet basis, at predefined intervals, and so on. For
example, the communication module 112 may use pilot data sent
during Wi-Fi handshake per packet data transfer, RSSI signal
strength information, use packet error conditions to adjust rates,
and so on. In one or more implementations, output power may
decrease values up to ten db and beyond using one or more of these
data items and assuming a relatively close range (e.g., small
distance) to the destination device, e.g., less than five
meters.
[0046] In addition to power control, power consumption may be
further reduced by bypassing the power amplifier 204, which
although represented as internal to the device may also be
configured as an external amplifier and thus the switch 210 may be
internally or externally deployed. For example, in some situations
the power amplifier 204 employed by the computing device 104 may
consume high static power even with low output power demands, such
as when class AB amplifiers are used. Accordingly, the
communication manager module 202 may employ a switch 210 to allow
the power amplifier 204 to be used for scenarios involving a
relatively significant range, e.g., access point 102 scenarios that
may involve a significant distance. The communication manager
module 202 may directly drive the antenna 206 for Wi-Fi Direct
circumstances (e.g., with the computing device 106 located at a
relatively close distance) and bypass the power amplifier 204 using
the switch 210 to save power, which may be particularly useful in
mobile applications but may also be useful in other applications.
For example, for power amplifiers that consume a base-load current
these techniques may avoid significant power consumption even at
low power levels, such as by employing the switch 210 that may
disable the power amplifier from the power supply 208, e.g., by
"turning off" a supply rail to the power amplifier 204. Thus, the
RF transmit power may be reduced to a minimal power level that is
sufficient to support a desired link quality, which therefore
reduces the RF footprint of the communication system.
[0047] Further, the use of relatively lower power may also result
in a reduction in noise in a wireless network 108, thereby further
saving power both for the device as well as other devices. For
instance, disruption to other devices within the range of other
devices that engage in wireless communication may be reduced by
having each device reduce the amount of output power used, e.g., in
office and other high density environments. Thus, if in an office
environment, a number of devices within the 2.4 GHz/5 GHz
unlicensed band range may share a single frequency if the reduced
RF power footprint is small enough to create a low-noise floor for
the other devices. For example, wireless display functions may
create significant band noise due to bandwidth utilization and thus
decreasing the amount of power will reduce the radio frequency (RF)
footprint and further minimize the disruption to devices on the
same frequency. The smaller the RF footprint and the more efficient
the non-overlapping channel reuse is implemented the greater the
density of wireless devices on the same frequencies can be
realized.
[0048] FIG. 3 depicts a procedure 300 in an example implementation
of wireless communication techniques that relate to control of a
power amplifier to transmit data. The following discussion
describes techniques that may be implemented utilizing the
previously described systems and devices. Aspects of each of the
procedures may be implemented in hardware, firmware, or software,
or a combination thereof. The procedure is shown as a set of blocks
that specify operations performed by one or more devices and are
not necessarily limited to the orders shown for performing the
operations by the respective blocks. In portions of the following
discussion, reference will be made to the environment 100 of FIG. 1
and the system 200 of FIG. 2.
[0049] A sending device detects whether communications between a
receiving device and the sending device comply with a predefined
link quality (block 302). The detecting, for instance, may be based
at least in part on an error rate or a scan of one or more wireless
channels during one or more non-transmit cycles. Further, the
detecting may be performed on a per packet basis, at predefined
intervals (e.g., based on number of packets transmitted, passage of
predefined amounts of time), and so on.
[0050] Responsive to a determination that the communication comply
with the predefined link quality, a power amplifier of the sending
device is bypassed to transmit a wireless communication to be
received by the sending device (block 304). The determination, for
instance, may be based on the detection above. If it is determined
that the receiving device is within range based on the predefined
link quality, the communication manager module 202 may bypass the
power amplifier 204 using a switch 210 or other techniques and
disable the power amplifier such that a supply rail to the power
amplifier 204 from the power supply 208 (e.g., a battery, "plug in"
source, and so on) is disabled. The communication manager module
202 may then communicate directly with the antenna 206 to transmit
the wireless communication (e.g., one or more packets) without the
aid of the power amplifier 204. In this way, the sending device may
reduce the amount of power used to perform the wireless
communication, reduce an amount of interference caused by the
wireless communication with other wireless devices that would
otherwise be within range of the interference, and so on.
[0051] However, responsive to a determination that communication do
not comply with the predefined link quality, a power amplifier of
the sending device is used to transmit a wireless communication to
be received by the sending device (block 306). Thus in this
instance, the sending device may use the additional operational
range afforded through use of the power amplifier 204, such as to
comply with operational ranges of IEEE standards.
[0052] Accordingly, a wireless communication may be received by a
receiving device from the sending device that was communicated
without using the power amplifier of the sending device when the
communication comply with the predefined link quality (block 308).
Thus, power used by the sending device may be conserved and reduce
interference caused by the communication. Additionally, a wireless
communication may be received by a receiving device from the
sending device that was communicated using the power amplifier of
the sending device when the communications do not comply with the
predefined link quality (block 310). In this way, the operational
range of the computing device may be extended in instances in which
the devices are not within the predefined range.
[0053] Wireless Buffering and Streaming Techniques
[0054] FIG. 4 depicts a system 400 in an example implementation in
which existence of a buffer on a receiving device is leveraged by a
sending device. In this illustrated example, a computing device 104
sends data (e.g., streams the data) via a wireless connection to
the other computing device 106. The communication modules 112, 114
of the respective computing devices 104, 106 are shown in greater
detail as including a respective communication manager modules 402,
404 and antennas 406, 408. The communication manager module 404 is
further illustrated as including a frame buffer 410, which may be
used to cache frames to be rendered by the computing device
106.
[0055] Depending on the configuration there may be two or more
frame buffers and/or streams, which may be used to support a number
of wireless sources as shown in FIG. 6. For example, at the
wireless display there may be a buffer and/or streams associated
with each of the wireless AN sources being received by the display.
Thus, the frame buffer 410 may be representative of a plurality of
different frame buffers that may be utilized for a plurality of
different streams. This data may then be processed (e.g., scaled)
and merged into a master frame buffer and/or streams that the
display uses to generate a final image on the display. There are a
variety of other techniques that may be used to handle management
of the multiple wireless video sources onto a single screen as
further described in relation to FIG. 6.
[0056] A variety of traditional wireless display solutions involve
power consumption above desirable targets for mobile applications,
i.e., for computing devices that rely on a battery for power.
Fortunately, many scenarios include significant time periods when
updates to the wireless display are unnecessary, e.g., for web
browsing, instant messaging (IM), music, presentations that do not
involve active animations, and so on. Traditional solutions,
however, continue to transmit frames 412 with identical content,
thereby wasting power of both the sending and receiving device as
well as resulting in introducing additional and needless noise to
the environment that could be avoided.
[0057] In this example, additional control signaling by the
communication manager module 402 of the sending computing device
104 and a frame buffer 410 of the receiving computing device 106
are leveraged such that frames which have new content are
transmitted from the source device but redundant frames are not,
e.g., frames that have matching content.
[0058] In this case, the additional control signals contain control
data to cause the wireless display to repeat a particular frame
until a new frame is provided. The source transmission portion of
module 112 may then enter a sleep mode until a new frame is to be
sent to the wireless display. Responsive to this, the internal
frame buffer 410 may be used to drive the target display until a
new frame is sent. Beyond this, frame rates may be reduced from
traditional (60 Hz/50 Hz) rates with lower frame rates being sent
to the target display with associated control signals.
[0059] For example, a presentation may involve a relatively static
display, e.g., a slide that does not change until an input is
received. Accordingly, the system may send the frame but then
determine that the information has not changed and therefore send a
"repeat" command to the wireless display. The wireless display may
then display this frame (e.g., over and over) until the source
device sends a new frame. During this period there may be little to
no wireless video information sent and therefore the power consumed
by the source device and noise that otherwise may occur in the
environment from transmitting the video information is reduced.
[0060] Additionally, control signals may also be used to send the
portions 414 of the frame 412 that is being updated. This may work
for a variety of different content, such as web pages with active
portions (e.g., an ad) where the majority of the frame 412 is not
active. Further, extender concepts may also be leveraged where
video and audio streams are sent independent to UI streams. Thus,
when the overlaying UI frame is quiet, the video updates for the
subsection of the display where video is presented are sent. In
additional embodiments, control data may also be used for
animations and object manipulation.
[0061] FIG. 5 depicts a procedure 500 in an example implementation
of wireless communication techniques that relate to wireless
buffering and streams. The following discussion describes
techniques that may be implemented utilizing the previously
described systems and devices. Aspects of each of the procedures
may be implemented in hardware, firmware, or software, or a
combination thereof The procedure is shown as a set of blocks that
specify operations performed by one or more devices and are not
necessarily limited to the orders shown for performing the
operations by the respective blocks. In portions of the following
discussion, reference will be made to the environment 100 of FIG. 1
and the system 400 of FIG. 4.
[0062] A determination is made by a sending device that a second
frame that is to be transmitted by the sending device to a
receiving device includes at least a portion that is a repeat of a
corresponding portion of a first frame that was transmitted by the
sending device to the receiving device (block 502). A communication
manager module 402, for instance, may determine that a frame is
repeated that is to be wirelessly transmitted from the computing
device 104 to another computing device 106. The frame, for
instance, may be part of a presentation or other content that
includes a relatively static display of content.
[0063] Responsive to the determination, at least a portion of the
first frame, which matches the portion of the second frame, is
caused to be repeated for display by the receiving device without
transmitted the portion of the second frame by the sending device
(block 504). Continuing with the previous example, the
communication manager module 402 may form a control signal to cause
the communication manager module 404 of the computing device 106 to
repeat at least a portion of a frame stored in a frame buffer 410.
In an implementation, the portion may encompass a substantial
display area of the frame. In another example, the sending device
does not send a control signal or a frame to the receiving device.
The receiving device may then detect this lack of data (e.g., frame
and/or control signal) and therefore repeat a frame that has
already been received by the receiving device. In this way, the
receiving device may act without receipt of data from the sending
device to repeat a frame.
[0064] Also responsive to the determination, a sleep mode may be
entered by one or more hardware devices or subsystem of the sending
device until an update to the first frame is to be transmitted to
the receiving device that includes content that is not included in
the first frame (block 506). The communication manager module 402,
for instance, may cause hardware one or more components of the
computing device 104 that are involved in wireless transmission to
enter a sleep mode to reduce power consumption by the computing
device 104. This may include reducing power supplied to the
hardware components but still keeping a baseline level of power
available such that the components may be quickly awakened. This
may also include turning off a supply rail to the one or more
components to reduce power consumption completely or near
completely. A variety of other examples are also contemplated.
[0065] Further responsive to the determination, a transmission
frame rate of the sending device to the receiving device may be
reduced (block 508). The communication manager module 402, for
instance, may determine that a static display is to continue.
Accordingly, the communication manager module 402 may reduce the
frame rate thereby conserving power and reducing interference in
the wireless environment with other devices that engage in wireless
communication.
[0066] One or more extender concepts may also be employed by the
sending device to separate streams to be transmitted to the
receiving device (block 510). The extender concepts, for instance,
may be configured to cause video, audio and/or user interface
streams to be transmitted separately. In this way, updates to each
of these streams may be communicated without involving the other
streams.
[0067] Accordingly, the receiving device may receive one or more
control signals and then repeat at least a portion of a frame
stored in a frame buffer (block 512) as well as employ other of the
previous described techniques for wireless communication described
in the above blocks. Although examples of buffering and streaming
techniques were described, a variety of other techniques may also
be employed without departing from the spirit and scope thereof,
examples of which may be found in the following section.
[0068] Wireless Display Techniques
[0069] FIG. 6 depicts a system in an example implementation in
which wireless display techniques are shown. In this example, two
mobile computing devices 602, 604 are in wireless communication
with another computing device, illustrated as a display device 606.
As stated in relation to FIG. 1, however, the computing devices may
assume a wide variety of other configurations.
[0070] The display device 606 as illustrated receives wireless data
from the mobile computing devices 602, 604. In response, the
display device 606 portions an available display area, which in
this instance is to divide the display area down the middle
although other examples are also contemplated, such as to employ
picture-in-picture techniques having portions of various sizes that
may be adjustable by a user of the display device 606.
[0071] For example, for a three-dimensional display an entire
display area of the display device may be used but configured to
display particular content to particular users by leveraging
glasses (e.g., LCD shutter glasses) typically worn by such users.
Through synchronization between the wireless display and the
glasses, each user may view different content and this display may
appear simultaneous to the users.
[0072] Further, the sending devices may be configured to take
advantage of this portioning For example, the mobile communication
devices 602, 604 may be configured to reformat the data being sent
to the display device 706 to have an aspect ratio, resolution, and
so on that is configured to approximate and even match the
portions. In this way, the devices may send a lesser amount of data
than would otherwise be sent if the full display area was consumed
by the data, e.g., video. A wide variety of other implementations
are also contemplated without departing from the spirit and scope
thereof.
[0073] FIG. 7 depicts a procedure 700 in an example implementation
of wireless communication techniques that relate to display of
content from a plurality of devices. The following discussion
describes techniques that may be implemented utilizing the
previously described systems and devices. Aspects of each of the
procedures may be implemented in hardware, firmware, or software,
or a combination thereof. The procedure is shown as a set of blocks
that specify operations performed by one or more devices and are
not necessarily limited to the orders shown for performing the
operations by the respective blocks. In portions of the following
discussion, reference will be made to the environment 100 of FIG. 1
and the system 600 of FIG. 6.
[0074] Two or more streams are received wirelessly at a display
device from respective two or more computing devices (block 702).
As shown in FIG. 6, for instance, the wireless display device 606
may receive streams of content from first and second mobile
computing devices 602, 604.
[0075] The display device may then automatically portion a display
area of the display device such that content from the two or more
streams is displayable concurrently by the display device (block
704). Continuing with the previous example, the display device 606
portions a display area into halves as illustrated such that
content is displayable concurrently from the plurality of mobile
computing devices 602, 604. Further, picture-in-picture techniques
may be employed such that a user may change a size of the portions,
reposition the portions, and so on. A variety of other portioning
techniques are also contemplated.
[0076] For example, the display area may be portioned so that a
first stream is viewable using a first pair of three dimensional
viewing glasses but not a second pair of three dimensional viewing
glasses and content from a second stream is viewable using the
second pair of three dimensional viewing glasses but not the first
pair of three dimensional viewing glasses (block 706). In this
example, the display device 606 may be configured for
three-dimensional display through communication with the three
dimensional viewing glasses, e.g., LCD shutter glasses. In this
example, larger portions may be displayed (e.g., overlapping even
to the point of consuming an approximate entirety of the display
area) and appear concurrent to two or more users, even though the
users may view different content from different streams.
[0077] The data may also be reformatted by respective ones of the
two or more computing devices according to respective portions via
which the data is to be displayed by the display device (block
708). The display device 606, for instance, may communicate with
the mobile computing devices 602, 604 to provide details regarding
an available resolution, aspect ratio, and so on of a portion that
is to be used to display content from the device. The mobile
computing devices 602, 604 may then format the content accordingly
such that this reformatting may be "offloaded" from the display
device 606. Other implementations are also contemplated, such as
reformatting that is performed by the display device, use of
predefined portions such that the reformatting may be performed
automatically and without user intervention by the mobile computing
devices, and so forth.
[0078] Dual Band Communication
[0079] FIG. 8 illustrates an example system 800 in which
functionality of a wireless device that involves a plurality of
bands is leveraged to provide wireless communication that employs
two or more of the bands. In this illustrated system 800, the
communication module 112 is shown in greater detail as employing a
communication manager module 802, a 2.4 GHz band module 804, a 5.0
GHz band module 806, and respective antennas 808, 810. Other
implementations are also contemplated, such as use of a dual-band
antenna.
[0080] Techniques are described in the following that may be used
to leverage independent hardware that is available on many
conventional devices to support a plurality of bands (e.g., both 5
GHz and 2.4 GHz bands) simultaneously, and without significant
reconfiguration of the hardware. Traditionally, this radio
frequency (not baseband) hardware of the separate bands is not
shared between the bands, although in some cases, a common
phase-locked loop (PLL) is used but may be replicated by a vendor.
Accordingly, in one or more implementations wireless communication
techniques may be employed to leverage two or more bands, such as
to communicate control information 812 over the 2.4 GHz band and a
data payload 814 over the 5.0 GHz band.
[0081] In another example, a wireless channel within a band (e.g.,
2.4 or 5.0 GHz) may be used for audio/visual and associated control
information while another wireless channel within the band may be
used for general wireless networking traffic.
[0082] Adjacent channels, e.g., non overlapping channels, may also
be used where one is used primarily for access point internet data
and the second is used for wireless display. For example, this may
be performed in both 5 GHz and 2.4 GHz bands simultaneously to
further increase bandwidth.
[0083] Techniques are also contemplated that use beacon signals to
avoid loss of data sent to the device during Wi-Fi display
operations. For example, the beacon may be checked for return data
and used to interleave the transmission for wireless display.
[0084] Further, as wireless display is transmission oriented for
the most part, special packet ACK techniques may be leveraged on
the receiving side (e.g., the wireless display) to reduce
"listening" on the wireless display channel.
[0085] In an implementation, many of the baseband portions of the
system may be designed to handle larger bandwidth (e.g., more than
20 MHz) with dual (e.g., 40 MHz) to multi-channel (802.11ac-80 MHz
and beyond) solutions. Accordingly, this hardware may be
multiplexed from its present dual+ channel single orthogonal
frequency division multiplexing (OFDM) stream to also handle dual
independent OFDM streams, even if these occur at very different
frequencies since associated baseband data can be the same. In
other words, the Fast Fourier Transform (FFT) engines, Viterbi, and
bit processing engines of the communication module 112 may process
frames over two independent streams (e.g., access point 102
internet based traffic and Wireless Display). Typically, antennas
for 2.4 GHz and 5 GHz are also different enough that separate
antennas are used even if packaged in one component as
illustrated.
[0086] In addition implementations systems may employ aspects of
this functionality that do or do not support concurrent 2.4 and 5
GHz operation. For example, time-division multiplexing may be
performed between bands. In another example, two channels in either
2.4 or 5 GHz band may be used. In an example implementation of the
second example, two independent 20 MHz streams may be used. Again,
one may run at high power to communicate with an access point 102,
but the second may use low power to simply reach a relatively close
computing device (e.g., a device within a predefined range such
that a power amplifier is not used) as described in relation to
FIGS. 2 and 3.
[0087] FIG. 9 depicts a procedure 900 in an example implementation
of wireless communication techniques that relate to wireless
communication that leverages a plurality of bands. The following
discussion describes techniques that may be implemented utilizing
the previously described systems and devices. Aspects of each of
the procedures may be implemented in hardware, firmware, or
software, or a combination thereof. The procedure is shown as a set
of blocks that specify operations performed by one or more devices
and are not necessarily limited to the orders shown for performing
the operations by the respective blocks. In portions of the
following discussion, reference will be made to the environment 100
of FIG. 1 and the system 800 of FIG. 8.
[0088] Data is obtained for communication from a sending device to
a receiving device (block 902). The data, for instance, may be
obtained through execution of one or more applications, received
from another device, located in local or remote storage, and so on.
Thus, the data may originate from a variety of different
sources.
[0089] First and second modules of the sending device are employed
to communicate the data over the first and second bands
simultaneously to the receiving device (block 904), such as over
2.4 and 5.0 GHz bands. For example, each of the bands may utilize
one or more channels to communicate with a same device, different
devices, and so on.
[0090] The communication manager module 802 may also use a variety
of other techniques to perform this communication. For example, the
communication manager module 802 may use the first module and
corresponding first band to communicate control information and the
second module and corresponding second band to communicate data
(block 906). In another example, the communication manager module
802 may use beacon signals to interleave a transmission for
wireless display by a wireless display device (block 908) as
previously described. Further, the communication manager module may
handle a plurality of independent orthogonal frequency division
multiplexing (OFDM) streams using the first and second modules
(block 910). For instance, the Fast Fourier Transform (FFT)
engines, Viterbi, and bit processing engines of the communication
module 112 may process frames over two independent streams (e.g.,
access point 102 internet based traffic and Wireless Display).
[0091] The communication manager module 802 may also employ
time-division multiplexing between the first and second bands
(block 914). This time-division multiplexing may be performed by
channels within a band, by the different bands, and so on. Further,
the communication manager module 802 may also employ techniques
that were described in relation to other sections. For instance,
the communication manager module may use the first or second
modules to vary an amount of power used by the first or second
modules based on whether a receiving device is within a predefined
range (block 914). A variety of other examples are also
contemplated without departing from the spirit and scope
thereof.
[0092] Wireless Decoding Techniques
[0093] FIG. 10 depicts a system 1000 in an example implementation
in which wireless decoding techniques are employed. The computing
device 104 and another computing device 106 are illustrated as
engaged in wireless communication. The communication module 112 of
the computing device 104 is illustrated in greater detail as
employing a communication manager module 1002, a decoding module
1004, and an antenna 1006.
[0094] In this example, the communication module 112 is configured
to determine whether the receiving device (e.g., the computing
device 106) is capable of decoding a source content format. If so,
encoded data may be communicated by the communication module 112
without being decoded by the decoding module 1004. This also allows
the target display to further improve image quality if
appropriate.
[0095] In scenarios where the type of displayed items may be
identified, the communication manager module 1002 may employ
different codecs and/or codec rates to reduce the amount of traffic
on the wireless communication link. Because the wireless
communication may be performed via a packetized network (e.g.,
802.11 standards), a reduction in traffic may also have a power and
noise floor advantage. For gaming, for instance, use of a H.264
encoder may be appropriate. For UI and solutions that support
object-like manipulation, wireless traffic may drop dramatically by
sending objects and animation control versus sending data for each
frame. For scenarios like Internet browsing, motion JPEG may be an
alternative to preserve quality and data traffic. This may be
performed by leveraging multiple processing techniques such as
frequency profile, frequency gradients, temporal changes, edge
change detection and other video and image progressing algorithms
as part of a decision tree to select an appropriate codec (e.g.,
compression algorithm) for use in encoding the video frame.
[0096] Further, to minimize transmit RF power, different
audio/visual (AN) compression solutions for given types of media
content may be used by the communication manager module 1002. For
example, compression type and ratios may be adjusted on a per frame
or sub frame basis to minimize the radio frequency (RF) power used
to maintain a reliable RF link.
[0097] In an implementation, the devices (e.g., computing devices
104, 106) perform a scan to locate a possible 20 MHz in the target
frequency band that is as "free" as possible in comparison with
other bands before starting the link. This further allows spatial
diversity of multiple wireless display users. This scan may also be
done if high error conditions occur in a band that is being used by
the devices, when a clean channel is detected, in response to a
request to change to the new contention free channel is sent to the
wireless display, and so on. In addition, beam forming may be used
to reduce power requirements and minimize the RF Channel footprint
for a given segment or spatial area.
[0098] In one or more implementations, a receiving device such as a
wireless display may provide requests to a source device to change
to a different channel. In response, the source may tell the
receiving devices (e.g., sinks) to which channel the device is to
move. In this way, the source may drive multiple receiving devices
in a contention free manner, although other implementations are
also contemplated in which the receiving device is used to manage
communication. For example, in scenarios in which multiple sources
are driving into a single sink this could be reversed or a master
source could be defined amongst the sources that specifies which
channel to use for wireless communication, e.g., AN transactions.
In another example, the receiving device may be made aware as to
which data is missing (e.g., media frames) and provide a
recommendation to the sending device to change to a new channel
once a given threshold is exceeded.
[0099] FIG. 11 depicts a procedure 1100 in an example
implementation of wireless communication techniques that relate to
communication of frames. The following discussion describes
techniques that may be implemented utilizing the previously
described systems and devices. Aspects of each of the procedures
may be implemented in hardware, firmware, or software, or a
combination thereof. The procedure is shown as a set of blocks that
specify operations performed by one or more devices and are not
necessarily limited to the orders shown for performing the
operations by the respective blocks. In portions of the following
discussion, reference will be made to the environment 100 of FIG. 1
and the system 1000 of FIG. 10.
[0100] One or more frames are obtained by a sending device to be
wirelessly transmitted to a receiving device (block 1102). The
frames, for instance, may be generated by an application that is
executed locally by the computing device 112, from local storage of
the computing device 112, obtained remotely via a network, and so
on.
[0101] A type of content is determined for one or more frames to be
transmitted wirelessly by a sending device to a receiving device
(block 1104). For instance, the frames may be involved in streaming
video, part of a presentation, include scenes from a video game,
obtained via a browser, part of execution of an application (e.g.,
a user interface), from a video camera, and so forth. Accordingly,
each of these types may have specific characteristics that may be
leveraged to reduce power consumption, noise and interference, and
so on that may be involved in wireless communication of the frames.
The determination may be performed in a variety of ways, such as
based on a frequency profile, frequency gradients, temporal
changes, edge change detection, and so forth.
[0102] A codec is identified to be used to encode the one or more
frames based at least in part on the determined type (block 1106).
Responsive to a determination that the one or more frames are not
encoded using the identified codec, the one or more frames are
encoded using the identified codec (block 1108). Continuing with
the previous example, some types of codecs may be particularly
suited for encoding particular types of frames. For gaming, for
instance, a H.264 codec may be used to encode the frames. For user
interfaces that support object-like manipulation, wireless traffic
may be reduced by sending objects and animation control versus
sending data for each frame. For scenarios like Internet browsing,
motion JPEG may be an alternative to preserve quality and data
traffic. A variety of other examples are also contemplated.
[0103] The one or more frames may also be compressed based at least
in part on the determination of the type of content (block 1110).
For example, a codec or compression algorithm may also be chosen
based on characteristics of the wireless channels that are used to
transmit the data. Further, this choice may be performed at a
variety of time frames, such as at a per frame or sub-frame
basis.
[0104] The sending device may also change to a different channel
chosen by the sending device in response to a request received at
the source device from the receiving device (block 1112). For
example, a receiving device (e.g., a wireless display device) may
determine that there is a large amount of noise on a current
channel and therefore send a communication to the sending device
(e.g., a mobile device) to change the channel used to communicate
with the sending device. The sending device may then choose a new
channel and communicate this information back to the receiving
device. Thus, in this example the sending device manages the
wireless communication although other examples are also
contemplated.
[0105] A variety of other wireless communication techniques are
also contemplated, such as to dynamically adjust a compression
ratio, an amount of change, change from one codec to another, beam
forming, FEC (Forward Error Correction) and so on.
[0106] Mobile Device Wirelessly Sharing a Screen with Other
Devices
[0107] Mobile communication devices have become increasing powerful
and capable of being highly connected and capable of acting as
relatively large storage devices capable of complex tasks from
gaming to photo editing. However, even though display devices
employed by mobile communication devices have grown from average
sizes below three inches in diagonal to close to four inches, pan
and zoom may still be involved when reading typical web pages,
emails, and so on. These devices are also typically limited in an
ability to input content or control applications with limited
on-screen or small keyboards on these devices. Accordingly,
techniques are described that may be used to enhance the input and
output of the mobile communication device in circumstances where a
second display and/or input device is available.
[0108] In one or more implementations, the mobile communication
devices may "remote" its display and input mechanism (e.g., touch,
buttons, and so forth) to a simple display device via wireless
display for the screen content and a control back channel. This may
be used to support a variety of different modes of operation:
[0109] 1) Simple remote usage where the user simply sees a larger
device similar to tablet device. However, in this case, there is no
separate processor, memory, WAN communications, and so on thereby
allowing a lower cost, increased mobility, and ability to
synchronize. The experience may also be enhanced by allowing a
higher resolution display to be supported on the remote device via
scaling or direct rendering to the larger size. [0110] 2) The
remote screen can be used as a display device, and the phone with a
copy (clone) on the display is used such that control is
accomplished from the phone. [0111] 3) The remote screen can act as
a secondary display, and the phone can display different content,
contextual content, keyboards, and so on. Control may occur from
both the remote display and phone. In the first cases, the phone
may stay in one's pocket. In cases 2) and 3) the remote may sit on
a surface, located in a dock, physically connected to the phone,
and so forth.
[0112] A variety of different functionality may be supported by
these techniques, such as an ability to remote phone interface via
optimized wireless display mechanisms (e.g., optimized link, remote
UI, animation, and display compression) where applications can run
completely on the phone, but interfaced to the user on the remote
display. Additionally, compressed videos may be embedded to be
natively decoded by remote display, remotely execute UI animation,
and adjust decoding based on content on remote side.
Further, touch (e.g., multiple finger gesture) and button clicks
may be embedded into a reverse channel of the mobile communication
device, and these commands may be replayed as if they were natively
executed on the mobile communication device. A conversion may also
be made on the remote device to convert touch points from remote
coordinates to native coordinates on the mobile communication
device. Further, these techniques may leverage integrated
Wi-Fi/decoder solution which provides communications, content
decoding, embedded frame buffer solution, and controller that is
cost efficient.
[0113] Traditionally, customers would either use their phone or
laptop for everything from web browsing to games to reading email.
Recently, however, a third device commonly referred to as a
"tablet" have become popular that have a screen size between phones
and laptops, higher battery life than both, touch interfaces and
applications similar to smart phones, and thickness similar to
smart phones. These devices allow users a third choice, but may
have significant costs (e.g., both device and carrier costs),
synchronization issues, and in some cases significant user
interface differences. The proposed solution allows customers the
option to have an internet tablet at significantly lower costs,
which is synchronized with their smart phone, and provides a common
user interface.
[0114] The solution may leverage techniques to identify, connect,
encode, transmit, and decode/display remotely. Standards such as
802.11, Wi-Fi Direct, uPNP, H.264, Motion JPEG, and so on may be
leveraged.
[0115] To build a remote tablet, a small portion of a typical
internet tablet may be used to construct a "thin" device. For
example, the tablet may be manufactured without an applications
processor, large flash or DRAM, WAN modem, and so on. Further, the
remote tablet may employ a relatively smaller battery, have Wi-Fi,
similar display, and leverage decoders and a relatively small
controller yet still provide a majority of typical internet tablet
functions. The remote display, when using the phone as the source
device, may be able to provide this experience however on a larger
display. If one excludes the display, these costs can represent
between twenty and fifty percent of the typical electrical bill of
materials of an internet tablet.
[0116] Further, the return channel may be employed for set-up and
acknowledgement of packets. As events from a touch controller or
buttons occur, these come to the small controller to be translated
and encoded. These may then be sent to the mobile communication
device to avoid latency between displayed objects and touch events.
Once received, the mobile communication device may decode these
events as if received from its touch controller. For dual screen
scenarios, the touch events may be received as second touch
controller.
[0117] Wi-Fi beacon signals or BT may also be used to allow wake up
of the mobile communication device from the remote device. Power
may also be shut-down on both sides after user controllable time
periods of in-operation.
[0118] Further, the mobile communication device's graphics
processing unit may be used to render not only to the local display
size, but also to a larger resolution allowing better viewing of
applications, web content, and so forth.
[0119] Negotiation between mobile communication device and the
remote tablet may be used to identify which compression types are
permitted. For example, applications may have their rendered
content encoded in either H.264 or motion JPEG after a frame has
been completed. In this example, the application is not made aware
that the frame is being transmitted for remote viewing. For cases
where a media player is used (or an embedded media player like in a
web page is called), the encoded media stream may be captured
before being decoded on the mobile communication device. The stream
is then encapsulated, and sent to the remote device to either be
decoded either within a graphics frame decoded and merged or simply
decoded full screen. Other types may also be more efficiently
encoded/decoded based on data type, but this may involve greater
awareness by applications of the remote device and potentially more
costs in the remote device. Audio streams may also be embedded in
either direction to support applications like conference calls,
media playback, and voice commands.
[0120] Mobile Device Broadcast to Multiple Wireless Displays
[0121] To display content on multiple displays using traditional
techniques involved the use of splitters, and cables that were
routed to individual displays. This presents a problem of setup
difficulties and this solution is meant to address this problem.
Traditional wireless solutions (e.g., over short to medium
distances) do not support broadcasting to multiple displays. This
solution allows a mobile communication device to broadcast its
content wirelessly to multiple devices.
[0122] The mobile device (e.g., which may also be referred to as a
source device) using the techniques described herein is capable of
broadcasting its content (whether it is an audio/video, pictures,
data, screen display, or others) to multiple wireless displays
(shall now be known as sink devices) at the same time. In this way,
broadcasting of content from a source device to multiple sink
devices at the same time may be supported.
[0123] For example, a user may initiate the broadcast feature on
the source device and select which sink devices to which the
content is to be broadcast. The user may then select multiple sink
devices within range of the source device. Once the links between
the source device and the sink devices are established, the user
can then choose the content on the source device to be broadcast.
For instance, the user may select to broadcast the source device's
screen content to the sink devices. In this case, if the user is
playing an audio/video content on the source device, while it's
content is also broadcast to the sink devices. Upon reception of
the content, the sink devices may then display the content of the
source device. The links between the source device and sink devices
may be bidirectional to allow the handling of packet errors, link
controls, data transport, service establishments, and so forth.
[0124] Mobile Device Wireless Screen Share with Other Devices
[0125] This technique allows a user to share screen content of a
device (whether it be pictures, audio/video, data, etc.) with
multiple devices when the link between the devices are established.
This allows other devices to display the shared content along side
with the local content on the device.
[0126] For example, the mobile device (shall now be known as source
device) is capable of wirelessly screen sharing its content
(whether it is an audio/video, pictures, data, screen display, or
others) with other devices (shall now be known as sink devices) and
vice versa. This allows the sink device to view its local content
and the shared content. The shared content screen size can be
adjusted on the sink device. Thus, a variety of different
functionality may be supported by these techniques: [0127]
Wirelessly share screen content from a source device to multiple
sink devices when the devices are within their wireless range.
[0128] Allow the sink device to view the local content and shared
content. [0129] Shared content screen size is adjustable on the
sink device.
[0130] The devices are not limited to laptops, desktops, wireless
display, tablets, slates, and mobile devices. The source device may
be defined as a device providing content to be shared. The sink
device may be defined as a device receiving the shared content.
During a screen sharing session, multiple sink devices may be
allowed but a single device is designated as a source.
[0131] In this context, the user initiates the screen sharing
session on each of the devices. One of the devices is specified as
the source device, and the other devices are configured to be the
sink devices. Upon establishing the screen sharing session between
the devices, the sink device can display the shared content on its
screen.
[0132] The shared content screen size on the sink devices can be
configured by the user to full screen (maximize size) or restored
screen (adjustable size). During the screen sharing session, any
one of the sink devices can become the source device by requesting
role changes. Upon final negotiation of the role changes, the
devices are reconfigured accordingly and the new content sharing
begins.
[0133] Mobile Device Audio Synchronization with a Wireless
Display
[0134] When a device provides a video stream to a wireless display,
while the end user is listening to the audio at the device end, the
audio and video may be out of sync. This may be due to latency in
the compression, transmission and decompression which varies
depending on RF environment and video processing.
[0135] To enhance the audio & video (AN) synchronization when
the source device is providing content to a wireless display while
the audio content is being played locally, a mechanism may be
employed to dynamically synchronize the A/V content. For example,
an audio buffer and/or stream may be used that dynamically adjusts
the play point and/or rate to account for the system latency to
ensure the audio at the source is synchronized with the video at
the remote end point.
[0136] There are a variety of different mechanisms that may be
utilized. For example, if the source device supports a microphone
the audio buffer control system may compare a test tone being
received locally by that originating from the display. The tone,
for instance, may be implemented as a relatively short burst
outside the human acoustic range and/or imperceptible short
duration. The control system may then measure the latency and
adjust the audio buffer play state and/or rate appropriately to
align the A/V.
[0137] In another example, the source device may transmit a RF
timing packet to the end point at the display. The end point may
then respond and the source devices may measure the RF delay. The
round trip time coupled with the known or estimated encode &
decode latency may be summed together to provide the total system
latency measure for packet latency. A variety of other examples are
also contemplated.
Conclusion
[0138] Although the invention has been described in language
specific to structural features and/or methodological acts, it is
to be understood that the invention defined in the appended claims
is not necessarily limited to the specific features or acts
described. Rather, the specific features and acts are disclosed as
example forms of implementing the claimed invention.
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