U.S. patent application number 10/116217 was filed with the patent office on 2003-10-16 for system and method supporting infrared remote control over a network.
Invention is credited to Neuman, Darren D..
Application Number | 20030195969 10/116217 |
Document ID | / |
Family ID | 28453931 |
Filed Date | 2003-10-16 |
United States Patent
Application |
20030195969 |
Kind Code |
A1 |
Neuman, Darren D. |
October 16, 2003 |
System and method supporting infrared remote control over a
network
Abstract
The present invention relates to a system for wireless control
of home media sources that utilizes a home digital network to
transport packetized IR transmitter data to a remote location. The
system allows for flexible control of multiple devices that accept
IR commands without requiring additional wiring, and is independent
of any particular IR protocol.
Inventors: |
Neuman, Darren D.; (San
Jose, CA) |
Correspondence
Address: |
MCANDREWS HELD & MALLOY, LTD
500 WEST MADISON STREET
SUITE 3400
CHICAGO
IL
60661
|
Family ID: |
28453931 |
Appl. No.: |
10/116217 |
Filed: |
April 4, 2002 |
Current U.S.
Class: |
709/229 |
Current CPC
Class: |
H04N 21/6587 20130101;
H04L 12/282 20130101; H04N 21/4135 20130101; H04N 21/637 20130101;
H04N 21/43615 20130101; H04L 12/2803 20130101; H04N 21/43622
20130101; H04N 9/87 20130101; H04N 21/42646 20130101; G08C 2201/40
20130101; H04N 5/775 20130101; H04N 21/42221 20130101 |
Class at
Publication: |
709/229 |
International
Class: |
G06F 015/16 |
Claims
What is claimed and desired to be secured by Letters Patent is:
1. A system for controlling media sources across a network,
comprising: a first interface device operatively coupled to the
network and located with a device for reviewing media; a second
interface device operatively coupled to the network located with a
media source; said first interface device adapted to convert
commands from a wireless remote to a format compatible with said
network; and said second interface device adapted to convert
commands for said first interface device into a wireless format for
re-transmission to said media source.
2. The system of claim 1 wherein the first interface device
comprises a first settop box and the second interface device
comprises a second settop box.
3. The system of claim 1 wherein the first interface device
comprises a signal processor that generates data packets
representative of the commands from the wireless remote and
communicates said data packets over the network.
4. The system of claim 3 wherein the signal processor causes said
data packets to be buffered before communicating said data packets
over the network.
5. The system of claim 1 wherein the first interface device further
comprises a user interface that receives at least one command from
the wireless remote indicative of a type of wireless remote being
used, and wherein the first interface device generates the format
compatible with said network based on the type of wireless remote
being used.
6. The system of claim 5 wherein the first interface device further
comprises memory, and wherein the type of wireless remote being
used is determined by a comparison of the at least one command to
information stored in the memory.
7. The system of claim 1 wherein the first interface device further
comprises a wireless receiver that receives the commands from the
wireless remote, wherein the first interface device generates the
format compatible with said network by sampling the wireless
receiver, and wherein the first interface device communicates the
samples generated over the network.
8. The system of claim 1 wherein the first interface device
generates the format compatible with said network using a pulse
width modulation scheme.
9. The system of claim 8 wherein the pulse width modulation scheme
comprises generating a pulse width value using the commands from
the wireless remote and encoding the pulse width value.
10. The system of claim 1 wherein the second interface device
comprises a signal processor that receives and decodes data packets
representative of the commands from the wireless remote, and
reconstructs an original signal from decoded data.
11. The system of claim 10 further comprising a wireless
transmitter for broadcasting the original signal.
12. The system of claim 11 wherein the first interface device
receives a media signal from the media source over the network
based on the broadcasting of the original signal.
13. The system of claim 1 wherein the wireless remote comprises an
infrared remote control.
14. The system of claim 1 wherein the media source comprises one of
a videocassette recorder or a digital video disc player.
15. The system of claim 1 wherein the device for reviewing media
comprises a television.
16. The system of claim 1 wherein the network comprises a home
network.
17. A method of controlling media sources across a network,
comprising: packetizing a wireless control signal at a location of
a device for viewing media; forwarding the packetized control
signal over said network to a device located with a media source;
depacketizing the wireless control signal; retransmitting the
control signal into a room where the media source is located.
18. The method of claim 17 further comprising buffering the
packetized control signal.
19. The method of claim 17 further comprising determining a type of
device that generated the wireless control signal, and wherein
packetizing the wireless control signal is based on the type of
wireless device determined.
20. The method of claim 19 wherein determining the type of device
that generated the wireless control signal comprises receiving at
least one command indicative of the type of device and comparing
the at least one command to information stored in memory.
21. The method of claim 17 further comprising generating samples
based on the wireless control signal, and wherein the packetizing
is performed on the samples generated.
22. The method of claim 17 further comprising pulse width
modulating the wireless control signal, and wherein the packetizing
is performed using a pulse width modulated signal.
23. The method of claim 22 wherein pulse width modulating comprises
generating a pulse width value using the wireless control signal,
and wherein packetizing comprises encoding the pulse width value
generated.
24. The method of claim 23 wherein depacketizing the wireless
control signal comprises decoding the encoded pulse width
value.
25. The method of claim 17 further comprising receiving a media
signal from the media source over the network based on the
retransmitting.
26. The method of claim 25 further comprising causing the display
of media on the device for viewing media using the media signal
received.
27. A method of transmitting control signals in a media network
comprising: receiving a wireless control signal from a remote
control; digitizing the wireless control signal received;
generating at least one data packet using the digitized control
signal; and communicating the at least one data packet over the
network.
28. The method of claim 27 further comprising buffering the at
least one data packet prior to the communicating.
29. The method of claim 27 further comprising determining a type of
remote control that generated the wireless control signal, and
wherein generating the at least one data packet is based on the
type of remote control determined.
30. The method of claim 29 wherein determining the type of remote
control that generated the wireless control signal comprises
receiving at least one command indicative of the type of remote
control and comparing the at least one command to information
stored in memory.
31. The method of claim 27 wherein the digitizing comprises
generating samples based on the wireless control signal, and
wherein the at least one data packet is generated using the
samples.
32. The method of claim 27 wherein the digitizing comprises pulse
width modulating the wireless control signal, and wherein the at
least one data packet is generated using a pulse width modulated
signal.
33. The method of claim 32 wherein generating the at least one data
packet comprises encoding a pulse width value generated.
34. The method of claim 27 further comprising receiving a media
signal over the network based on the communicating.
35. The method of claim 34 further comprising causing the display
of media using the media signal received.
36. The method of claim 27 wherein the remote control comprises an
infrared remote control.
Description
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0001] [Not Applicable]
SEQUENCE LISTING
[0002] [Not Applicable]
BACKGROUND OF THE INVENTION
[0003] The development of home networks to distribute video content
digitally presents new problems to system designers seeking to
integrate the control of multiple devices in the home. An early
example is the use of coaxial cable to distribute analog video
content throughout a home. Although it was relatively easy to
connect multiple televisions to a common video source such as a VCR
located in a different room, the standard remote controls for the
VCR would not allow a homeowner to directly control a remotely
located VCR from the room where the TV was located, which is where
the operator typically would desire to view the video. In prior
analog systems, remote control of a source not located in the room
where the content was played was accomplished with either UHF radio
remote controls (an uncommon solution for home equipment and
susceptible to interference from neighbors) or more typically with
the use of infrared repeaters that would collect IR control signals
in a given room and then either retransmit them by bouncing them
down a hallway, send them by a dedicated wired connection to the
program source, or retransmit the signals using radio waves, again
suffering interference from other radio sources. All of these
techniques require additional dedicated components and wiring
making their installation relatively expensive.
[0004] There are also significant differences from control schemes
using dedicated "home run" wiring. Usually, dedicated wiring
control schemes must be wired from box-to-box separately from the
wires used to carry the analog video/audio signal. The control
wires can be used ONLY to carry command information. Dedicated
wiring control schemes are proprietary and do not work with all IR
remote controls (e.g., SONY S-link). They are usually based on
decoding the IR signal, and only sending the control word. The
invention described here does not require decoding the IR signal,
but rather works by reconstructing the IR signal at the central
box.
[0005] There are control schemes based on 1394 networks, however,
they rely upon one box controlling another through known control
word protocols, and do not seem capable of sending and
reconstructing the original IR signal. As such, they do not work
with existing IR remote controls, or existing A/V equipment. The
invention disclosed here operates with existing A/V equipment, and
it makes use of the home network and remote/central boxes to
receive, communicate on home network, and finally reconstruct the
original IR remote control signal, allowing for highly flexible
control with a minimum of additional wiring while preserving the
homeowner's investment in pre-existing A/V sources and
displays.
[0006] Further limitations and disadvantages of conventional home
A/V control approaches will become apparent to one of skill in the
art, through comparison of such systems with the present invention
as set forth in the remainder of the present application with
reference to the drawings.
BRIEF SUMMARY OF THE INVENTION
[0007] Aspects of the present invention may be found in a home
network system that is based on digital transmission. The system
allows the user to send remote control commands across the home
network, rendering unnecessary a physically separate control path
for commands to the remotely located A/V source.
[0008] In one embodiment, the remote settop box (located with the
TV, stereo speakers, PC, or other unit capable of playing or
displaying an A/V program) is networked to a central settop box
(located where the A/V source such as a VCR, DVD player, or file
server is located). The network is any of Ethernet, HPNA, HCNA,
wireless 802-11 or other digital network. The remote settop box can
receive the infrared remote control signals, process them,
construct packets of control information, and send the packets over
the network to the central settop box. The central settop box can
receive and decode the packets, and use an IR blaster to
re-transmit the remote control signals into the room with the other
AV equipment.
[0009] Such a system allows a user in the bedroom, for example, to
use a normal IR remote control to turn on a VCR that is remote in
the family room. The video signal would leave the VCR as an analog
signal and be digitized and compressed by the central settop box,
typically using an MPEG encoder. The VCR signal is then sent over
the home network to the remote settop box in the bedroom. Control
signals from the VCR IR remote are relayed from the remote settop
box, over the digital network, and to the VCR, thus giving the user
all the normal operations expected.
[0010] Alternatively, a small remote-only box can be placed on the
network anywhere in the home where IR remote capability is needed.
This would allow a remote to work totally independently of the
location of the AV equipment. All that is required in this
embodiment is an IR digitizer connected to the home network.
[0011] By taking advantage of the digital back channel available on
the home network, a number of schemes that allow for the remote
control using existing IR controls of A/V equipment are possible,
without the disadvantages of prior schemes. Other aspects,
advantages and novel features of the present invention, as well as
details of an illustrated embodiment thereof, will be more fully
understood from the following description and drawings, wherein
like numerals refer to like parts.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 shows an overview of a typical implementation of one
embodiment the invention.
[0013] FIG. 2 is a more detailed overview showing the basic system
and an alternate scheme for use with A/V sources that are not
connected to the digital home network.
[0014] FIG. 3 is an alternate embodiment that includes a central
decode and command distributor that allows multiple display media
to share multiple program sources.
[0015] FIG. 4a is a block diagram of a remote settop box in
accordance with one embodiment of the present invention.
[0016] FIG. 4b is a logical diagram of the packet structure of
packetized IR control data in accordance with one embodiment of the
invention.
[0017] FIG. 4c illustrates one embodiment of a simple buffering
scheme for use in sending and re-assembling IR control data
packets.
[0018] FIG. 5 is a block diagram of a central settop box in
accordance with one embodiment of the present invention.
[0019] FIG. 6 is a block diagram of one embodiment of a central
decode and command distributor for use with the system of FIG. 3,
for example.
[0020] FIG. 7 is a diagram of a logical translation function
wherein the system of FIG. 3 can be adapted to control devices
other than A/V sources.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Referring to FIG. 1, in one embodiment of the invention, the
home network system comprises 2 boxes: a remote settop box 101 and
a central settop box 102. The central settop box 102 includes a
home network interface 103 and an IR packet decoder 104, although
these functions could be separated into two physically distinct
units. An IR cable 105 connects the IR packet decoder to an IR
Blaster 106, whose construction may be conventional. A program
source such as a VCR 107 is connected to network interface 103 by
either an analog or digital link 108. An IR remote control 109 can
now send IR commands 110 to remote settop box 101. Remote settop
box 101 packetizes the IR commands 110 and forwards them across
digital network 111 to network interface 103. IR packet decoder 104
translates packetized IR commands received from the network 111 and
forwards them to IR blaster 106. IR blaster 106 broadcasts an IR
blaster command 115 to conventional program source 107. The program
source 107 responds to the commands and sends its program content
to the digital network 111 via link 108 and the network interface
103. Finally, the remote display or speakers 112 receives the
program from source 107, even though source 107 may be separated
from IR remote 109 and display 112 by one or more walls 113.
[0022] Remote Box.
[0023] FIG. 4a is a detailed view of the remote settop box 101. The
IR receiver 401 within the remote box is typically a photodiode,
with a simple RC filter 402 at the output. The RC filter 402 is
sufficiently broadband to receive all varieties of IR remote
control signals. Most IR remote controls 109 generate signals 110
that are either baseband signals with pulse widths in the range of
3-7 .mu.s on/20 .mu.s off or AM modulated carriers around 30-40
KHz. Buffer/amplifier 403 forwards the received signal to the
remote signal processor 405 over interrupt line 404.
[0024] The signal 110 is received, digitized, and packetized
efficiently for distribution over the home network. The remote
signal processor 405 in the remote settop box may perform this
function in a number of ways:
[0025] 1. Programmed Remote: In this scheme, the user can program
the remote settop box via a user interface 406 to identify the type
of remote control in use. Different remote controllers use
different protocols, and different transmission pulse
widths/frequencies. The remote settop box control logic 407 can
then use a signal processing scheme specifically designed for that
remote by matching the received pattern with a known patterns
stored in ROM 408, or trying alternate schemes until a scheme that
works is selected. Usually, this consists of timing specific pulse
widths, and demodulating a signal to decode digital bits. The
sequence of digital bits contain remote control commands. In this
scheme, only the decoded bits for the commands are sent over the
network, resulting in very few bits transmitted, a few
kilobits/second. This scheme has the advantages of being very
immune to noise (some lights put off IR noise that can interfere),
and has the advantage of consuming very few bits of network
bandwidth.
[0026] 2. Learned Remote: This scheme is very similar to the
programmed remote scheme, however, rather than the user programming
the type of remote from a user interface, the signal processor
implements a learning algorithm by taking a sample remote control
signal 110 from the user. For example, the user could place the
system in `learn mode`, point the remote control at the receiver,
and press the remote control buttons. The signal processor then
only needs to match a received signal with a previously learned
remote. It shares similar advantages as the programmed remote
above.
[0027] 3. Brute-force: In this scheme, the remote settop box simply
samples the IR receiver at a very high frequency, and sends the
information from every sample time across the network. Most IR
receivers operate off a very high gain receiver, so as to receive
weak signals, or signals of variable strength in a room. Because of
this, the resulting IR signal is usually limited to either a 0 or 1
level, or may be digitized with very low quantization (4 bit
quantization may be sufficient) with an A/D converter. It is also
not necessary to sample at a very high frequency, as most IR remote
controls operate with low frequency signals. However, some remote
controls save battery life by making pulse widths shorter. A
typical system may sample the IR signal at 1 Mhz (1 .mu.s period)
with 4 bit quantization. This signal is then packetized, and sent
across the network. The advantage of this system is that it will
work with any remote control, regardless of the use of AM modulated
carrier or baseband signal, as long as the bandwidth of the signal
is less than 500 KHz. There are simple improvements on this scheme
to save bandwidth, such as applying simple run-length compression
or other lossless compression algorithms on the signal prior to
transmission. Given that most IR pulses are much longer than 1 us,
the signal should compress very well, on the order of 6-10.times.
compression, reducing the network bandwidth to well below 1
Mbit/s.
[0028] 4. PWM: This scheme takes advantage of the nature of remote
control IR signals. All of these signals can be amplified to a very
high level, resulting in essentially a stream of pulses of IR
signal which are converted to 0-1 pulses of various width by
sampling circuitry 409. At this point the signal has been converted
to a pulse-width modulated signal: 1
[0029] The pulse width modulated signal can be filtered by pulse
width coding circuit 410 to remove any pulses less than 1 .mu.s in
width (this is the lower limit of pulse widths used in remote
control signals). The filter removes the narrow pulse, and adds
this time to the previous pulse width. The pulse width is measured
with a high frequency clock, for example, 10 Mhz or 100 ns
precision. The pulse width value is then coded as an 8 bit number,
with some mechanism to encode very long periods of time with no
change in level. This could be done by reserving the value 0
(0.times.00) to mean extend the pulse width count by 256. This very
simple run-length coding could be improved with other simple data
compression schemes. In this method, the bit rate on the network is
usually very low, but could peak if there is a lot of IR noise in
the system, or if the receiver is triggered by a high speed IR
signal. The lower limit occurs if there is a slow IR signal, and is
generally a single 8-bit number every 25.6 .mu.s using a 10 Mhz
sample clock, resulting in 312 Kbits/second. If there is no IR
signal, the bandwidth is generally 0, as no information is sent.
The upper limit occurs if there is a noisy signal received. Pulses
just over 1 .mu.s in length generally require an 8 bit number every
1 .mu.s, or about 8 Mbits/second. This can be adjusted by making
the sample clock longer, changing the filter characteristics of the
pulse-eating filter, or by using entropy-coding of Huffman coding
the pulse width signals. A peak data rate of 1 Mbit/second provides
a reliable system that works with most commercially available
remote controls. The advantages of this system is that it is
independent of the protocol on the remote control, does not require
a user to program the system, has some noise filtering and noise
immunity, and requires no bandwidth when there is no IR signal
received.
[0030] The Remote Network Interface.
[0031] The remote network interface 412 in the remote settop box
101 is controlled by a software application running on control
logic 407 to manage this process over the network. It implements a
number of functions, for example:
[0032] 1. Establish connection with the application in the central
settop box
[0033] In one embodiment, on power-up, the remote settop box 101
sends a message to the central settop box 102 to establish an IR
connection. This could also be done when the user selects such a
feature on the remote settop box. This essentially allows the
remote settop box IR application software to pass information to
the central box, which is also running an IR application software.
Additionally, after the connection is made, the remote settop box
or the central settop box sends brief messages every few minutes to
ensure that the other box is still connected. Upon discovering a
disconnect, the remote and central boxes attempt to re-establish a
connection, with time-out and retry if the other box is still
disconnected.
[0034] 2. Remove locally relevant IR signals for remote box and
route to local processor.
[0035] The remote settop box may have it's own IR remote
controller, and may process the commands from this controller. The
control logic 407 examines the signal from the signal processor
405, determines if it matches the IR signal for the remote settop
box control, and if so, does not transmit this on the network I/F
412. Instead it sends the resulting command to any local processor
that may need to process commands for the remote box operation.
This has at least two benefits: it allows the settop remote box to
operate off the same IR receiver 401 as the network application,
and also prevents re-transmission of the local IR signal, thus
allowing multiple remote settop boxes on a network, while
preventing other similar boxes from receiving these signals
inadvertently through the network 111. In one embodiment, any
remote settop box needs to respond only to its IR control.
[0036] If a homeowner wants to have multiple identical remote
settop boxes in a single network, and wants the ability to control
any of them through the network 111, then the remote settop box 101
and the IR controller for that box are programmed so that each
remote control will only work with a single box, for example. All
other signals are routed on the network for use by other boxes.
[0037] 3. Packetize IR signal from the signal processor (possibly
with compression)
[0038] The IR application software constructs a packet of
information 430 to be used by the central settop box. One
embodiment of a packet structure is shown in FIG. 4b. This
information starts with some header information, followed by a
number of PWM samples 434. The header information 431 contains
control bits to indicate the start of transmission (if the IR
receiver was previously quiet) and end of transmission 432. The
header indicates a packet length to allow the central box to know
how much information is to be received. The header indicates a
packet count or sequence number 433, which is simply an increment
of +1 from the previous packet. Each packet in sequence has an
increasing count. The count can be used by the central settop box
to order the data, and allows simple buffering models (see below).
Finally, the packets are a fixed, finite length of time. 50 ms
covers most IR transmitter times for a single control code word.
Using the PWM approach above, a 50 ms packet contains about 4000
bytes for typical IR codes with pulse periods of 25 .mu.s or less
if compression is used.
[0039] Buffer and time stamp data for transmission.
[0040] In one embodiment, the data that is transmitted is buffered
prior to transmission, and buffered on receipt. FIG. 4c shows one
embodiment of how packets are "bundled" for network transmission.
This ensures that the data is transmitted without gaps on the
network. The network is typically packet based, and may have other
information traffic. The resulting effect is that packets of IR
information are not sent continuously. By using a buffer 411 on the
transmitter side, and on the receiver side 506, the network
delivery time does not affect the system operation. The buffer
model can be very simple. For example, the system could buffer 4
packets on the transmit side, not start transmitting until 4
packets are available to send, and use 4 packets on the receiver
side, while holding IR data at the central settop box until 4
packets are received. After the startup condition, packets are
generated every 50 ms in the remote settop box 101 and consumed in
the central settop box 102 every 50 ms, so the system works as long
as the data is sent within 4.times.50 ms or about 200 ms. As most
IR remote controls 109 repeat the IR signal multiple times, the
system is not sensitive to occasional network drop-outs.
[0041] 5. Ensure low delay operation (numbered packets to assemble
sequence).
[0042] In one embodiment, low delay operation ensures that the user
does not perceive annoying delays from when they push a button on
an IR remote until the operation starts to take effect. This may be
achieved by two means. For example, first the data is sent to the
network while the button is still being pressed. A typical key
press may last a few seconds, and the signal processing and
application software must not wait until the button press is
complete to send data packets 430. Second, the buffer model for
buffer 411 keeps a small number of packets of information in the
buffer to ensure low delay from input (IR received at remote box)
to output (IR blasted at central box). The buffer model above uses
8 packets of 50 ms each for a 400 ms total delay. This may be
modified for different system performance goals.
[0043] FIG. 2 shows a variation on the basic system embodiment
shown in FIG. 1. In this embodiment, multiple remote settop boxes
101, 201 and program sources 107, 207 are connected to network 111.
A stand-alone remote capture device 215 can be positioned at any
convenient point on network 111 so that IR remotes 109, 209 can be
used in any room, even rooms that contain no program sources 107,
207 or display or speaker devices 112, 212. Home digital network
interface 202 is conventional and has digitizing ports for
digitizing and forwarding digital audio 216 and video 217 across
network 111.
[0044] Furthermore, from FIG. 2 it can be seen that the remote IR
control across the digital home network can be accomplished even
for program sources that are not connected to the network, since
source 107 in FIG. 2 can receive IR commands through its IR
receiver 114 and send analog output to the display device via a
"homerun" connection 218 (such as ordinary coaxial cable or
S-video) to display device 112.
[0045] FIG. 3 shows another embodiment of a system arrangement in
accordance with the present invention. In this scheme, the
functions of remote settop box 301 are built into display device
312, or may be as in FIG. 1. Multiple display devices 312, 313 are
connected to network 111. Furthermore, multiple clusters of program
sources 340, 341 are also connected to the network. Central decode
and distribute device 350 manages connections between the remote
settop boxes and different media clusters, so that multiple remotes
and sources can be accessed simultaneously.
[0046] Central Settop Box:
[0047] One embodiment of the central settop box is shown in FIG. 5.
The IR blaster 106 is typically an LED. In FIG. 5 it is shown as
part of the settop box, although it could be located remotely in a
convenient transmitting location, high on a wall for example. Most
IR remote controls are either baseband signals with pulse widths in
the range of 3-7 .mu.s on/20 .mu.s off or AM modulated carriers
around 30-40 KHz. The packets are received from the network 111,
depacketized, processed and driven to the IR blaster 106. The IR
blaster 106 will transmit the signal into the room, where it will
bounce off objects and reflect back into the AN equipment 107 in
the room.
[0048] The central signal processor 501 in the central settop box
is generally more complex than the remote settop box. Signal
processor 501 is implemented on a microprocessor with the functions
described below. It takes the packets of data 430 from the network
111, decodes the data according to the algorithm chosen, and using
a time base similar to the remote settop box, reconstructs the
original signal. An example would be using the PWM method described
above, decompressing the values if entropy coding or Huffman coding
was used to compress the signal in the remote settop box 101. After
decompression, a 10 Mhz clock 503 counts out the relevant clock
cycles to recreate the pulse width of the signal, and the output of
the pulse counter drives the LED either on or off via a driver 504
(full power) into the room.
[0049] The central settop box also runs a software application that
manages the system over the home network. The operations are, for
example:
[0050] 1. Establish connection with remote boxes. This is different
than above, as the central settop box "pings" the network 111 to
find if any remote boxes have been powered up. It does this on a
regular period, on the order of one second to one minute. It also
establishes separate connections with each remote settop box, and
maintains separate connection information. This supports multiple
remote settop boxes in a home, since each may use different A/V
equipment in the central location.
[0051] 2. De-code and parse information received on the network.
Decode and parse routine 505 examines the header information 431,
and if a new IR signal is being started, creates buffer space for
the receipt of the signal. The routine 505 examines the packet
count 433, and if packets are lost or received out of order, they
are reordered properly in the buffer, or re-requested from the
remote settop box. Routine 505 starts the signal processing and IR
blaster after a minimum number of packets have been received. The
central settop box waits for a few packets to arrive to ensure that
the buffer 506 does not underflow during an IR event. In one
embodiment, 4 packets is the minimum number of packets that are
received and present in buffer 506 before processing begins.
Buffering ends when the header 432 indicates the end of IR signal
reception.
[0052] 3. Maintain separate buffers for each remote settop box.
Semaphore control is maintained over the IR blaster 106 and signal
processing. The IR blaster is a shared resource, so it is generally
controlled carefully. When a network packet 430 is received from a
remote settop box 101, it requests a path through multiplexer 507
by setting a "semaphore" for its buffer. If a later network packet
is received from a remote box 201, the buffer 509 or 510 should
fail to receive the semaphore and control over the IR blaster.
Remote box 101 maintains control over the IR blaster through buffer
508 until the entire IR signal is received on the network,
buffered, depacketized, and sent out the IR blaster output. Signals
from other settop boxes can be held in buffers 509 and 510.
Further, there is generally a dead time on the order of 100 ms or
more after remote box 101 finishes, before remote box 201 is
allowed to gain the semaphore and buffer 509 or 510 is released to
the IR blaster. This dead time allows the A/V equipment 107 to
clearly delineate the end of the IR command, and not confuse the
following signal with the previous signal. After this dead time,
the buffered packets received from remote box 201 are processed and
sent to the IR blaster. While any remote settop box has control of
the semaphore and IR blaster, all other packets from other remote
boxes are buffered up in the receive buffer 506, but are not be
processed. This ensures that a single IR signal is sent completely
before another signal is sent in the event that multiple remote
controls are used in different rooms at the same time.
[0053] FIG. 6 shows a "central decode and universal translate"
device that can be used with the system shown in FIG. 3, for
example. This device may have all of the functions of the central
signal processor 501, except instead of converting packets into IR
signals, the converted packets are examined for header information
that identifies the appropriate program source and remote for each
packet. This device can be connected to network 111 at any
convenient point through network interface 602. The packets are
then routed to the appropriate media source cluster 340. This is
possible since the central decoder 350 is made "aware" of which
remotes are associated with each source via user input from
interface 606. A look-up table 650 correlates each remote 109 with
each source 107 or media cluster 340. Each packet is then
appropriately addressed by re-packetizer 660 and sent back across
the network 111. By using this central universal translate, the
"any to any" IR control shown in FIG. 7 can be accomplished.
[0054] While there may be other choices for sample rates, packet
size, buffer models, these are easily changed in the
implementation, and can be optimized for the best quality operation
while utilizing the lowest bandwidth. Different systems may prefer
higher noise immunity and trade off bandwidth if the system network
111 uses 100 Mbit Ethernet, while another system may sacrifice
noise sensitivity for bandwidth if using 20 Mbit HPNA or 10 Mbit
Ethernet.
[0055] Embodiments of the present invention are quite different
than known systems that utilize convention radio retransmission of
IR signals. Notably, the system described here has at least the
following advantages:
[0056] Single network connection to systems already exists with the
home network used to transmit digital video.
[0057] Minimal additional cost when integrated into a settop
box.
[0058] Compatible with multiple remote controls operating
simultaneously in a single home.
[0059] Not susceptible to radio interference from within the home,
or from neighbors.
[0060] Compatible with multiple sources (multiple remote boxes)
within a single home.
[0061] The foregoing description is representative, however
variations will be apparent to those of skill in the art and the
invention is in no way limited to the specific example
described.
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