U.S. patent application number 11/077315 was filed with the patent office on 2005-07-21 for clock-based time slicing.
This patent application is currently assigned to Nokia Corporation. Invention is credited to Auranen, Tommi, Laiho, Kimmo.
Application Number | 20050157650 11/077315 |
Document ID | / |
Family ID | 27660083 |
Filed Date | 2005-07-21 |
United States Patent
Application |
20050157650 |
Kind Code |
A1 |
Laiho, Kimmo ; et
al. |
July 21, 2005 |
Clock-based time slicing
Abstract
A system that allows mobile terminals to periodically remove
power from at least some components is disclosed. The mobile
terminal receives bursts of content. Some of the bursts of content
include relative time information identifying the transmission time
of a subsequent burst of content. The mobile terminal may remove
power from a receiving module during times when the mobile terminal
is not scheduled to receive content bursts.
Inventors: |
Laiho, Kimmo; (Turku,
FI) ; Auranen, Tommi; (Turku, FI) |
Correspondence
Address: |
BANNER & WITCOFF
1001 G STREET N W
SUITE 1100
WASHINGTON
DC
20001
US
|
Assignee: |
Nokia Corporation
Espoo
FI
|
Family ID: |
27660083 |
Appl. No.: |
11/077315 |
Filed: |
March 10, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11077315 |
Mar 10, 2005 |
|
|
|
10075434 |
Feb 14, 2002 |
|
|
|
Current U.S.
Class: |
370/235 ;
348/E5.006; 348/E5.108; 348/E5.127; 370/468 |
Current CPC
Class: |
Y02D 10/24 20180101;
H04N 21/4305 20130101; H04N 21/4432 20130101; G06F 1/3203 20130101;
H04W 52/0229 20130101; Y02D 70/1224 20180101; H04N 21/426 20130101;
H04W 52/0216 20130101; H04N 5/4401 20130101; H04N 21/41407
20130101; H04N 21/43637 20130101; H04N 21/4126 20130101; H04N
21/4622 20130101; H04W 52/0248 20130101; Y02D 30/70 20200801; H04H
20/42 20130101; H04N 21/235 20130101; Y02D 70/168 20180101; G06F
1/329 20130101; H04N 21/26216 20130101; H04N 21/262 20130101; H04H
60/13 20130101; H04N 5/63 20130101; Y02D 10/00 20180101 |
Class at
Publication: |
370/235 ;
370/468 |
International
Class: |
H04J 003/16 |
Claims
1-29. (canceled)
30. A transmitter unit located at a head-end location for
communicating data to a mobile terminal, the transmitter unit
comprising: a transmission module for communicating data over a
network, wherein said transmission module transmits data comprising
a value of a relative time period between bursts of data
transmissions; a component for formatting the data into bursts
having a predetermined bandwidth and interval, and communicating
the data to said transmission module;
31. The transmitter unit of claim 30, wherein said component
performs time division multiplexing on the data.
32. The transmitter unit of claim 30, wherein said component
formats the data into bursts having a predetermined bandwidth that
is less than or equal to a maximum bandwidth.
33. The transmitter unit of claim 30, further including a buffer
that stores the bursts of data.
34. The transmitter unit of claim 30, wherein said data
communicated is a conventional information signal.
35. An encapsulater unit for formatting content at a head-end
location, the encapsulater unit comprising: an encapsulater capable
of encapsulating the content with a value equal to a relative time
period between bursts of data transmissions; a processor programmed
with computer-executable instructions for receiving the content
from said encapsulator and formatting the data into bursts; and an
interval module for calculating said value equal to the relative
time period between bursts of data transmissions and communicating
said value to said encapsulater;
36. The encapsulater unit of claim 35, wherein said encapsulater
uses a multiprotocol encapsulater.
37. The encapsulater unit of claim 35, wherein said encapsulater
encodes into Internet protocol packets.
38. A power unit located at a mobile terminal for providing power
to at least part of the mobile terminal, said battery unit
comprising: a power source for providing power to at least a
receiving module located at the mobile terminal; a power management
module for selectively applying power from said power source to at
least said receiving module; and an extraction module for
extracting relative timing information communicated from a head-end
location and communicating the relative timing information to said
power management module;
39. The power unit of claim 38, wherein said power source is a
battery.
40. The power unit of claim 38, wherein said power source is a
stationary power source.
41. The power unit of claim 38, wherein power from said power
source to at least a receiving module is removed for a time period
less than a first relative time period extracted from said relative
timing information communicated from a head-end location.
42. The power unit of claim 38, wherein said power management
module removes power from at least the receiving module for power
off time periods that correspond to the relative time periods.
43. The power unit of claim 38, wherein said extraction module
extracts the relative timing information from digital video
broadcast modulation data.
44. The power unit of claim 38, wherein said power management
module operates in a constant on state for a period of time when an
error condition occurs at the receiving module.
45. The power unit of claim 44, wherein said error condition is
caused by a burst of data being lost while being transmitted from a
transmitter module to said receiving module.
Description
FIELD OF THE INVENTION
[0001] The invention relates to broadcast systems. More
particularly, the invention provides systems and methods that
reduce power consumption of mobile terminals between transmitted
bursts.
BACKGROUND OF THE INVENTION
[0002] Conventional digital video broadcast (DVB) systems transmit
streams of content to digital video broadcast receivers via a
transmission medium. The transmission medium typically includes a
coaxial cable, satellite or wireless broadcast station. Each
transmission medium has a limited bandwidth and typically divides
the available bandwidth into a plurality of channels. FIG. 1
illustrates a typical transport stream 100 that is transmitted to a
digital video broadcast receiver. As is shown in FIG. 1, the
typical transport stream is continuous and occupies a bandwidth
that is less than the maximum bandwidth of a channel.
[0003] Mobile terminals are increasingly being used to provide new
services to users. Mobile terminals are popular because they are
light weight and do not require a connection to a stationary power
source, such as a standard electrical outlet. One of the
limitations of mobile terminals is the battery life of the mobile
terminal. Processing of low bit rate content, such as streaming
content, can have a negative impact on the life of a mobile
terminal battery. As a result, users can only receive and view
streaming content for a limited time period. Prior art solutions to
the limited battery life problem that results from receiving and
processing streaming content include carrying extra batteries and
utilizing more expensive or larger batteries. Obviously, the prior
art solutions take away from the attractiveness of mobile
terminals.
[0004] Therefore, there exists a need in the art for systems and
methods that allow mobile terminals to receive and process
streaming content while efficiently utilizing the batteries of
mobile terminals.
SUMMARY OF THE INVENTION
[0005] One or more of the above-mentioned needs in the art are
satisfied by the disclosed systems and methods that periodically
remove power from at least some components of mobile terminals.
Streaming or bursty content is transformed into bursts of content
having a bandwidth greater than the original content. Power may be
removed from receiving modules in between time periods in which the
bursts of content are received. Relative timing information
regarding the timing of bursts may be included in the bursts. Among
other advantages, the use of relative timing information allows
mobile terminals to remove power from receiving modules without
requiring strict synchronization with a broadcast source and the
calculation of latency delays.
[0006] A first embodiment of the invention provides a method of
providing streaming content. The method includes receiving a
continuous information stream containing content and creating first
and second bursts that contain portions of the content. A relative
time period between a transmission of the first burst and a
transmission of the second burst is encoded in the first burst.
[0007] In another embodiment, a method of processing bursts of
content data received at a mobile terminal is provided. The method
includes receiving a first burst of content and extracting a
relative time period until a transmission of a second burst of
content. After receiving the first burst of content, power is
removed from at least a portion of the mobile terminal for a time
period less than the relative time period.
[0008] In yet another embodiment of the invention, a mobile
terminal that processes bursts of content is provided. At least
some of the bursts of content include relative time information
relating to a next burst. The mobile terminal includes a receiving
module that receives bursts of content and an extraction module
configured to extract relative time periods from the bursts of
content. A power management module removes power from at least the
receiving module for power off time periods that correspond to the
relative time periods.
[0009] In other embodiments of the invention, computer-executable
instructions for implementing the disclosed methods are stored on
computer-readable media.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention is illustrated by way of example and
not limited in the accompanying figures in which like reference
numerals indicate similar elements and in which:
[0011] FIG. 1 shows a typical transport stream that is transmitted
to a digital video broadcast receiver;
[0012] FIG. 2 illustrates a system for transmitting and receiving
bursts of content, in accordance with an embodiment of the
invention;
[0013] FIG. 3 illustrates bursts of content that have been
formatted in accordance with an embodiment of the invention;
[0014] FIG. 4 illustrates a method of transmitting bursts of
content containing relative timing information to a mobile
terminal, in accordance with an embodiment of the invention;
and
[0015] FIG. 5 illustrates a method that may be used by a mobile
terminal to receive and process bursts of content in accordance
with an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] FIG. 2 illustrates a system for transmitting and receiving
bursts of content in accordance with an embodiment of the
invention. The content may include audio content, video content
and/or data. A head-end 202 transmits bursts of content to a mobile
terminal 204 via a digital video broadcast network 206. A single
mobile terminal is shown for illustration purposes only and with
the understanding that head-end 202 may transmit bursts of content
to numerous mobile terminals or other devices. Digital video
broadcast network 206 may include coaxial cable, a wireless
transmission station, a satellite or other transmission medium. Of
course, aspects of the present invention may utilize networks other
than digital video broadcast networks, such as pure Internet
protocol networks.
[0017] Head-end 202 may receive an information signal 208 at a
buffer 210. Buffer 210 may be a memory that stores segments of
information signal 208. An interval module 212 may be used to
determine a relative time period between the transmission of bursts
of content. The relative time period determined by interval module
212 may be a function of a maximum bandwidth of network 206, a
maximum bandwidth of a channel of network 206 or other factors,
such as power management efficiencies of the head-end and/or mobile
terminal.
[0018] A multiprotocol encapsulater 214 may be used to format the
content that will be transmitted to network 206. In one embodiment
of the invention, the relative time period determined by interval
module 212 is encapsulated into the content formatted by
multiprotocol encapsulater 214. A time source 216 may be used by
interval module 212 to calculate the relative time period between
bursts of content. A processor 218 may be programmed with
computer-executable instructions to receive the content from
multiprotocol encapsulater 214 and format the data into bursts
having a bandwidth and interval determined by interval module
212.
[0019] FIG. 3 illustrates a series of bursts 302, 304 and 306 that
may result from the processing performed by processor 218. Unlike
conventional transport stream 100 shown in FIG. 1, bursts 302, 304
and 306 shown in FIG. 3 are periodic and consume substantially all
of the available channel bandwidth. As will be described in detail
below, one of the advantages of the transmission scheme shown in
FIG. 3 is that power may be removed from components of mobile
terminal 204 between the reception of bursts. For example, between
time periods t.sub.1 and t.sub.2, no content is received at mobile
terminal 204. Therefore, power may be removed from at least
receiving module 222. Power may also be removed between time
t.sub.3 and t.sub.4. One skilled in the art will appreciate that
any power removed from any of the components of mobile terminal 204
may be reapplied shortly before the expiration of a time interval
between bursts to ensure that mobile terminal 204 is ready to
receive the next transmitted burst.
[0020] A transmission module 220 transmits the content bursts to
network 206 for ultimate delivery to mobile terminal 204. Of
course, aspects of the present invention may be used with systems
that include more than one information source 208. The
corresponding additional content bursts may be transmitted in
different channels of network 206 or may be time division
multiplexed with the first set of content bursts. Transmission
module 220 may include components for performing time division
multiplexing. Such components are readily available and well-known
to those skilled in the art.
[0021] Receiving module 222 may be coupled to a buffer 224. Buffer
224 may store the received content bursts for later processing. An
extraction module 226 may be used to extract the relative time
periods from the received bursts of content. A time source 228 may
be used as a local time source. In one embodiment, time source 228
may extract time information from standard transport stream time
and date tables. However, because timing information is preferably
relative rather than absolute, it is not necessary to synchronize
the head-end and the mobile terminal to a common time source. The
head-end and the mobile terminal may have independent time
sources.
[0022] Mobile terminal 204 may include a power management module
230 that receives the relative timing information extracted by
extraction module 226 and time information received from time
source 228 to remove and apply power to receiving module 222. As
has been described above, power may be removed from at least
receiving module 222 at times in which content bursts are not
received at mobile terminal 204. A processor 232 may be included to
perform functions such as receiving the content bursts stored in
buffer 224 and creating a continuous content stream.
[0023] Mobile terminal 204 may be implemented with a mobile
telephone, personal digital assistants, or other portable
electronic devices that may be used to present audio, data and/or
visual content to a user. Accordingly, mobile terminal 204 may
include a display 234 for displaying visual content to the user
and/or a speaker 236 for presenting audio content to a user.
[0024] Power management module 230 selectively applies power to one
or more components of mobile terminal 204 based on relative time
period information. As a result, it is not necessary for time
source 216 and time source 228 to be synchronized. It is sufficient
that each time source has a predetermined accuracy. The
predetermined accuracy may be selected based on efficiency
requirements of mobile terminal 204. Relatively more accurate time
sources allow mobile terminal 204 to apply power at shorter time
periods before the anticipation of receipt of bursts. With less
accurate time sources, power must be applied sooner to compensate
for the inaccuracies and ensure that mobile terminal 204 is ready
to receive bursts. Another advantage to utilizing relative time
period information is that latency delays may be automatically
considered. In particular, since the latency delays of successive
bursts are likely to be substantially the same, the relative time
period information is sufficient for determining when to apply and
remove power.
[0025] FIG. 4 illustrates a method for transmitting bursts of
content containing relative timing information to a mobile
terminal, in accordance with an embodiment of the invention. First,
in step 402, the head-end receives a content stream. The content
stream may be continuous. The content stream may be a conventional
information signal received from an information source, such as a
television station. Alternatively, the content stream may be a
conventional transport stream, such as transport stream 100 (shown
in FIG. 1).
[0026] Next, the head-end creates a first burst containing a
portion of the content in step 404. The bandwidth of the first
burst is greater than the bandwidth of the original content stream
received in step 402. Similarly, in step 406, the head-end creates
a second burst containing a portion of the content.
[0027] Next, in step 408 the head-end determines a relative time
period between the transmission of the first and second bursts. The
relative time period may be a function of the content of the
original content stream, the available bandwidth of the
transmission medium or the available bandwidth of a channel of the
transmission medium. The relative time period is encoded in the
first burst of content data in step 410. The relative time period
may be included in an Internet protocol (IP) packet, a
multiprotocol encapsulated frame, any other packet frame, a 3G or
GPRS channel or modulation data, such as transmitter parameter
signaling.
[0028] In step 412, the first burst is transmitted to the
transmission medium. After the relative time period has elapsed,
the second burst is transmitted to the transmission medium in step
414.
[0029] The relative time period may identify a time period from the
beginning of transmission of one burst to the beginning of
transmission of another burst. A duration of the burst may also be
included. In one embodiment of the invention, each burst may
include relative time period information that determines the time
between the transmission subsequent bursts. For example, the second
burst may include relative time period information that determines
the length of time before transmission of a third burst. In other
embodiments of the invention, relative time period information may
be included in bursts only when the relative time period between
the transmission of bursts changes.
[0030] FIG. 5 illustrates a method that may be used by a mobile
terminal to receive and process bursts of content in accordance
with an embodiment of the invention. First in step 502 a first
burst of content is received. The burst may be received at
receiving module 222 (shown in FIG. 2). In step 504, a first
relative time period is extracted from the first burst. The first
relative time period determines the time interval between
transmission of the first burst and the transmission of the second
burst.
[0031] In step 506 power is removed from at least a portion of the
mobile terminal for a time period less than the first relative time
period. As stated above, it might be desirable to apply power to
the components, from which power was removed, shortly before the
expiration of the first relative time period to ensure that the
mobile terminal is configured and ready to receive the additional
bursts of content. In one embodiment in the invention, power is
removed from receiving module 222. Receiving module 222 may include
components that consume relatively large amounts of power, such as
a demodulator. Of course, mobile terminal 204 may be configured so
that power is selectively applied to additional components. For
example, power may be removed from substantially all of the
components of the mobile terminal in between the reception of
bursts of content. Power may be removed from substantially all of
the components when, for example, the mobile terminal is receiving
content that will be presented to a user at a later time. Mobile
terminal 204 may receive the content and store the content in a
memory for later retrieval.
[0032] In step 508, power is provided to the components from which
power was removed and the mobile terminal receives a second burst
of content. The mobile terminal may also be configured to examine
all of the bursts of content to determine if additional relative
time information has been included. For example, mobile terminal
204 may examine the second burst of content to determine if a
relative time period between the transmission of the second burst
of content and the transmission of a third burst of content has
been included. Finally, in step 510 a continuous content stream is
created from the content contained in the first and second bursts.
Of course, a continuous content stream may be created from content
contained in any number of bursts.
[0033] One aspect of the invention includes a mechanism for
operating a mobile terminal when a burst is lost. A burst may be
lost because of interference or some error or fault condition. When
a burst is lost, the mobile terminal may be configured to operate
in a constant on state until another burst is received. In one
embodiment, the mobile terminal may be programmed to operate in a
constant on state after a predetermined length of time since the
reception of a burst. The predetermined length of time may be
chosen to slightly exceed the maximum expected length of time
between bursts.
[0034] The present invention has been described with reference to
mobile terminals. Selectively removing power from at least some
components of a mobile terminal may provide longer battery life.
The selective removal of power may also reduce interference and/or
reduce the generation of heat. As a result, aspects of the present
invention may be used with other broadcast receivers that do not
include batteries or that are not mobile.
[0035] While the invention has been described with respect to
specific examples including presently preferred modes of carrying
out the invention, those skilled in the art will appreciate that
there are numerous variations and permutations of the above
described systems and techniques that fall within the spirit and
scope of the invention.
* * * * *