U.S. patent application number 15/030751 was filed with the patent office on 2016-09-29 for network sensing systems and methods for power management.
This patent application is currently assigned to Entropic Communications, LLC. The applicant listed for this patent is ENTROPIC COMMUNICATIONS, INC.. Invention is credited to Yunhong Li, Mark O'Leary, Branislav Petrovic, Michail Tsatsanis.
Application Number | 20160282922 15/030751 |
Document ID | / |
Family ID | 52021452 |
Filed Date | 2016-09-29 |
United States Patent
Application |
20160282922 |
Kind Code |
A1 |
Petrovic; Branislav ; et
al. |
September 29, 2016 |
Network Sensing Systems and Methods for Power Management
Abstract
A communication device includes a communication port including
network interface circuitry; and a power control module configured
to awaken the communication device from a sleep mode, determine
whether a network is present at the communication port, and to
return the communication device to the sleep mode if it is
determined that a network is not present at the communication
port.
Inventors: |
Petrovic; Branislav; (La
Jolla, CA) ; Tsatsanis; Michail; (Huntington Beach,
CA) ; O'Leary; Mark; (San Diego, CA) ; Li;
Yunhong; (San Diego, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ENTROPIC COMMUNICATIONS, INC. |
Carlsbad |
CA |
US |
|
|
Assignee: |
Entropic Communications,
LLC
Carlsbad
CA
|
Family ID: |
52021452 |
Appl. No.: |
15/030751 |
Filed: |
November 20, 2014 |
PCT Filed: |
November 20, 2014 |
PCT NO: |
PCT/US2014/066661 |
371 Date: |
April 20, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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61906579 |
Nov 20, 2013 |
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61993938 |
May 15, 2014 |
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62001252 |
May 21, 2014 |
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62008917 |
Jun 6, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F 1/3296 20130101;
H04L 43/0811 20130101; H04L 41/12 20130101; G06F 1/266 20130101;
Y02D 50/42 20180101; G06F 1/3206 20130101; H04L 12/2801 20130101;
H04N 21/6168 20130101; H04L 12/2861 20130101; H04L 12/12 20130101;
G06F 1/3209 20130101; Y02D 10/171 20180101; H04L 43/50 20130101;
Y02D 50/20 20180101; H04N 21/6118 20130101; Y02D 30/50 20200801;
Y02D 50/40 20180101; Y02D 10/00 20180101; G06F 1/3287 20130101;
H04L 1/24 20130101; H04L 41/0833 20130101; H04L 12/10 20130101 |
International
Class: |
G06F 1/32 20060101
G06F001/32; G06F 1/26 20060101 G06F001/26; H04L 12/10 20060101
H04L012/10 |
Claims
1. A communication device, comprising: a housing; a communication
port including network interface circuitry; and a power management
module configured to awaken the communication device from a sleep
mode, determine whether a network is present at the communication
port, and to return the communication device to the sleep mode if
it is determined that a network is not present at the communication
port.
2. The communication device of claim 1, wherein the power
management module configured awaken from the sleep mode after a
predetermined time.
3. The communication device of claim 2, wherein the predetermined
time is less than 500 ms.
4. The communication device of claim 1, wherein awakening the
communication device from a sleep mode comprises awakening a power
management module from the sleep mode while other components of the
communication device remain in a sleep mode.
5. The communication device of claim 4, wherein the power
management module is further configured to awaken a predetermined
set of components of the communication device from the sleep mode
if the power management module determines that the network is
present at the communication port.
6. The communication device of claim 5, wherein the communication
device is configured to initiate communications on the network.
7. The communication device of claim 6, wherein the communication
device is configured to enter into the sleep mode after network
operations have ceased for a predetermined period of time.
8. The communication device of claim 6, wherein the power
management module is configured to return the communication device
to the sleep mode after network operations have ceased.
9. The communication device of claim 8, wherein returning the
communication device to the sleep mode after network operations
have ceased comprises the power management module remaining awake
and returning other components of the communication device to the
sleep mode.
10. The communication device of claim 8, wherein returning the
communication device to the sleep mode after network operations
have ceased comprises returning the entire communication device to
the sleep mode.
11. The communication device of claim 10, further comprising a
timer that remains active when the communication device is in the
sleep mode.
12. The communication device of claim 8, further wherein the
communication device is further configured to awaken from the sleep
mode to determine whether a network is present at the communication
port after a predetermined period of time in the sleep mode.
13. The communication device of claim 1, wherein the communication
device is further configured to return to the awake mode after a
predetermined period of time to determine whether a network is
present at the communication port.
14. The communication device of claim 2, wherein the communication
device is configured to initiate communications on the network.
15. The communication device of claim 14, wherein the communication
device is configured to return to the sleep mode after network
operations have ceased for a predetermined period of time.
16. The communication device of claim 14, wherein the power
management module is configured to return the communication device
to the sleep mode after network operations have ceased.
17. The communication device of claim 16, wherein returning the
communication device to the sleep mode after network operations
have ceased comprises the power management module remaining awake
and returning other components of the communication device to the
sleep mode.
18. The communication device of claim 16, wherein returning the
communication device to the sleep mode after network operations
have ceased comprises returning the entire communication device to
the sleep mode.
19. The communication device of claim 18, further comprising a
timer that remains active when the communication device is in the
sleep mode.
20. The communication device of claim 16, further wherein the
communication device is further configured to awaken from the sleep
mode to determine whether a network is present at the communication
port after a predetermined period of time in the sleep mode.
21. The Communication device of claim 1, wherein the network
interface circuitry comprises a transmitter, a receiver, and an
electrical connector.
22. The Communication device of claim 1, wherein the network is a
wireless network, and the network interface circuitry comprises a
transmitter, a receiver, and an antenna.
23. The communication device of claim 1, wherein the power
management module comprises a sensing module and a power control
module, and further wherein the sensing module is configured to
check for the presence of the communication network and alert the
power control module regarding whether the network is present at
the communication port, and the power control module is configured
to perform the operation of returning the communication device to
the sleep mode.
24. The communication device of claim 23, wherein the sensing
module and a power management module comprise computer program code
stored in a non-transitory storage medium and configured to run on
a processor or on a plurality of processors.
25. The communication device of claim 1, further comprising a power
supply and a plurality of electronic components configured to draw
energy directly or indirectly from the power supply, and wherein
the sleep mode comprises turning off some or all of the plurality
of electronic components to reduce the amount of energy drawn from
the power supply.
26. The communication device of claim 1, further comprising a power
supply and a plurality of electronic components configured to draw
energy directly or indirectly from the power supply, and wherein
the sleep mode comprises transitioning some or all of the plurality
of electronic components to a lower-power state to reduce the
amount of energy drawn from the power supply.
27. The communication device of claim 1, wherein determining
network is present at the communication port comprises listening
for a beacon at the communication port.
28. A method of power control in a communication device,
comprising: the communication device transitioning to a search mode
from a sleep mode; determining whether a communication network is
present at a communication port of the communication device; and
the communication awakening or remaining awake if it is determined
that network is present at the communication port.
29. The method of claim 28, wherein the search mode comprises an
awake mode for the communication device.
30. The method of claim 28, wherein the search mode comprises a
mode in which a power management module of the communication device
is awakened while other components of the communication device
remain in a sleep mode.
31. The method of claim 28, further comprising the communication
device initiating network operations on the network present at the
communication port.
32. The method of claim 31, further comprising determining whether
network operations have ceased, and if so, returning the
communication device to the sleep mode.
33. The method of claim 32, wherein the communication device
returning to the sleep mode comprises returning the entire
communication device to the sleep mode.
34. The method of claim 33, further comprising the communication
device returning to the search mode after it has been in the sleep
mode for a predetermined period of time.
35. The method of claim 31, further comprising the communication
device determining whether network operations have ceased, and if
so, returning the communication device to the search mode.
36. The method of claim 28, wherein the sleep mode comprises
turning off some or all of the plurality of electronic components
to reduce the amount of energy drawn from a power supply of the
communication device.
37. The method of claim 28, wherein the sleep mode comprises
transitioning some or all of the plurality of electronic components
to a lower-power state to reduce the amount of energy drawn from a
power supply of the communication device.
Description
TECHNICAL FIELD
[0001] The disclosed technology relates generally to communication
systems, and more particularly, some embodiments relate to network
sensing systems and methods for automatic power management.
DESCRIPTION OF THE RELATED ART
[0002] Energy consumption of electronic devices continues to be an
increasing concern in the electronics industry. This is true in the
commercial, consumer and military/DOD sectors. Accordingly,
electronic devices are being designed to consume less power through
the use of low energy demand components and automated power
management (e.g., automated unit shut down and restart).
[0003] It is common place today for electronic devices to
communicate with one another. One common way in which devices
communicate is by forming a network that includes two or more
devices. Devices within a network are commonly referred to as nodes
of the network. There are several ways that devices can be
organized to form a network. One such way is to form a MoCA network
specified by the well-known industry standard called "MoCA"
administered by the Multimedia over Coax Alliance. Such MoCA
networks are commonly established over the coaxial cables that are
typically used within homes and offices to distribute television
signals, such as cable television signals, satellite television
signals or direct broadcast video-terrestrial (DBV-T) signals. It
is common today for homes and offices to be wired with coaxial
cable having connectors conveniently located throughout the home or
office. Each such connector allows a device to connect directly to
each other device in the home or office that is connected to the
coaxial cable wiring.
[0004] MoCA networks allow devices to communicate with one another
at high speed over coaxial cabling using transmissions that are
modulated at designated frequencies. In accordance with MoCA, a
device that would like to become part of a MoCA network, first
listens on each of the plurality of designated MoCA frequencies
(i.e., attempts to receive signals transmitted by another node of a
preexisting MoCA network). The designated frequencies are commonly
referred to as MoCA channels. MoCA capable devices typically can
only listen to one channel at a time. Upon beginning the process of
attempting to join a MoCA network, the device will listen for a
predetermined time to each MoCA channel, one at a time in an
attempt to receive a beacon signal.
[0005] A beacon signal is defined by MoCA as a signal transmitted
by a particular MoCA network node, referred to as the network
coordinator (NC). The beacon is designed to be easy for a new node
attempting to join an existing MoCA network to acquire. The beacon
is transmitted at regular intervals by the NC. Therefore, if a MoCA
network already exists on the coaxial cable to which a new device
is connected, the new device will be able to acquire the beacon
when it initially listens to the MoCA channels.
[0006] If no MoCA network yet exists on the coaxial cable to which
the new device is connected, then the new device will start sending
out beacons of its own in an attempt to form a new MoCA network.
The new network will be formed by the new device and any other
device that is also seeking to join a MoCA network on the same
coaxial cable.
[0007] When a MoCA node initially powers up, the node will
typically start sending beacons over the last operating frequency
(LOF) used by that device. The LOF is the MoCA channel that the
device used last to communicate with other MoCA devices over a MoCA
network.
[0008] MoCA designates the timing used by a MoCA network to send
these beacons in an attempt to acquire or form a new network. This
timing requires that a new node attempting to join a MoCA network
listen for 40 seconds to each of the possible MoCA channels to
determine whether a MoCA network already exists. The new node will
listen to each channel one at a time for 1.05 seconds and then tune
to the next channel.
[0009] Typically, the node will listen to LOF first and then search
the channel with the lowest frequency. The node will then search
the LOF again. The node will then step up in frequency one channel.
The node then returns to listen again to the LOF. This pattern of
bouncing between the LOF and the next higher channel will continue
until reaching the channel with the highest frequency. This pattern
is then repeated in descending order from the channel with the
highest frequency to the channel with the lowest frequency with LOF
searched in between each other channel. This process of stepping up
and down one channel at a time continues for the 40 second
listening phase.
[0010] After 40 seconds, if no beacons are found, the new node will
determine that there is no existing network. Accordingly, the new
node will take the role of NC in an attempt to form a new MoCA
network. Accordingly, the new node will execute at least 100
"Beacon Phase Cycles" (BPCs). Each BPC consists of a period having
a duration randomly selected from the range of 0.1 to 1 second
during which the new node listens to one of the MoCA channels,
followed by 50 beacon cycles. The beacon transmissions sent during
the beacon cycles are sent on the same MoCA channel (i.e., the LOF)
with the assumption being that another new node that attempts to
join the network will search each of the possible channels during
its 40 second initial listening period and hear the beacons that
the beaconing node is transmitting.
[0011] Each beacon cycle is 10 milliseconds long and includes a
short burst transmission of the beacon followed by an admission
control frame (ACF). The ACF is a period of time during which the
new node will listen to hear whether another node has acquired the
beacon previously sent. The 50 beacon cycles are followed by
another period that randomly varies from 0.1 second to 1.05 seconds
during which the new node will listen to the LOF MoCA channel in an
attempt to form a MoCA network on the LOF channel. The combination
of the 50 beacon cycles followed by the 0.1 to 1.05 second
listening period constitute one BPC. A node that is has not yet
formed a network will execute 100 such BPCs and then enter a
listening phase for another 40 seconds during which the node will
search each of the possible channels to see whether a new network
has been formed on one of those other channels.
[0012] This process is repeated until a new network is either
formed or found. However, a problem arises when two or more devices
attempt to join a MoCA network at essentially the same time, each
having a different LOF. That is, if two or more MoCA enabled
devices connected to the same coaxial cable are powered up
together, each will listen for a beacon for 40 seconds. Since
neither is yet sending any beacons, neither will know of the
existence of the other. At the end of the 40 seconds, each will
time out without acquiring a network beacon. Therefore, they will
each start sending beacons on their respective LOF. This is not a
problem if the two nodes had the same LOF, since they will
eventually hear each other. However, if the two nodes have
different LOFs, then they will not hear each other. At the end of
the 100 BPCs, each node will enter the 40 second listening phase.
However, since the amount of time during which each is executing
the BPCs is essentially statistically the same, they will both
start listening at essentially the same time and the chances of one
hearing the other are very low. That is, the listening period
within each BPC is randomly determined to be between 0.1 and 1.0
seconds. Therefore, it is possible for there to be a different in
the total amount of time it takes each node to execute 100 BPCs.
However, since the duration of each BPC is random, the average
amount of time over the 100 BPCs, statistically, will be very close
to equal. Therefore, the two nodes will be synchronized and miss
each other for several hours before the synchronization of the two
nodes is sufficient disrupted to allow one to be transmitting
beacons while the other is listening on the LOF of the other. This
is typically not a significant problem, but for the fact that each
MoCA node that is searching for a MoCA network consumes a
significant amount of power.
BRIEF SUMMARY OF EMBODIMENTS
[0013] According to various embodiments of the disclosed
technology, devices and methods for providing power management for
communication devices based on the status of a device's connection
are disclosed. More particularly, the various embodiments of the
technology disclosed herein relate to power management based on the
presence or absence of a network attached to the device.
[0014] In some embodiments, a communication device, may include: a
housing; a communication port including network interface
circuitry; and a power management module configured to awaken the
communication device from a sleep mode, determine whether a network
is present at the communication port, and to return the
communication device to the sleep mode if it is determined that a
network is not present at the communication port.
[0015] The power management module may be configured to awaken from
the sleep mode after a predetermined time. The predetermined period
of time may be determined based on network parameters and MAC
protocols, and in some embodiments the predetermined time is less
than 500 ms.
[0016] In various embodiments, awakening the communication device
from a sleep mode comprises awakening a power management module
from the sleep mode while other components of the communication
device remain in a sleep mode. In further embodiments, the power
management module is further configured to awaken a predetermined
set of components of the communication device from the sleep mode
if the power management module determines that the network is
present at the communication port.
[0017] The communication device may be configured to initiate
communications on the network.
[0018] The communication device may be configured to enter into the
sleep mode after network operations have ceased for a predetermined
period of time. And, the power management module may be configured
to return the communication device to the sleep mode after network
operations have ceased. Returning the communication device to the
sleep mode after network operations have ceased may include the
power management module remaining awake and returning other
components of the communication device to the sleep mode. In other
embodiments, returning the communication device to the sleep mode
after network operations have ceased may include returning the
entire communication device to the sleep mode. A timer may be
included and the timer may remain active when the communication
device is in the sleep mode.
[0019] The communication device may be further configured to awaken
from the sleep mode to determine whether a network is present at
the communication port after a predetermined period of time in the
sleep mode.
[0020] The communication device maybe configured to return to the
awake mode after a predetermined period of time to determine
whether a network is present at the communication port, initiate
communications on the network, and return to the sleep mode after
network operations have ceased, or after network operations have
ceased for a predetermined period of time. Returning the
communication device to the sleep mode after network operations
have ceased may include the power management module remaining awake
and returning other components of the communication device to the
sleep mode. Returning the communication device to the sleep mode
after network operations have ceased may also include returning the
entire communication device to the sleep mode.
[0021] A timer can be included that remains active when the
communication device is in the sleep mode. The communication device
may be configured to awaken from the sleep mode to determine
whether a network is present at the communication port after a
predetermined period of time in the sleep mode.
[0022] In various embodiments, network interface circuitry may be
provided and can include a transmitter, a receiver, and an
electrical connector. The network may be, for example, a wireless
network, and the network interface circuitry comprises a
transmitter, a receiver, and an antenna.
[0023] The power management module may include a sensing module and
a power control module, and the sensing module may be configured to
check for the presence of the communication network and alert the
power control module regarding whether the network is present at
the communication port, and the power control module may be
configured to perform the operation of returning the communication
device to the sleep mode. The sensing module and a power management
module may include computer program code stored in a non-transitory
storage medium and configured to run on a processor or on a
plurality of processors.
[0024] The communication device may further include a power supply
and a plurality of electronic components configured to draw energy
directly or indirectly from the power supply, and wherein the sleep
mode comprises turning off some or all of the plurality of
electronic components to reduce the amount of energy drawn from the
power supply. The communication device may also include a power
supply and a plurality of electronic components configured to draw
energy directly or indirectly from the power supply, and wherein
the sleep mode comprises transitioning some or all of the plurality
of electronic components to a lower-power state to reduce the
amount of energy drawn from the power supply.
[0025] Determining a network is present at the communication port
comprises listening for a beacon at the communication port.
[0026] In still further embodiments, a method of power control in a
communication device, may include: the communication device
transitioning to a search mode from a sleep mode; determining
whether a communication network is present at a communication port
of the communication device; and the communication awakening or
remaining awake if it is determined that network is present at the
communication port.
[0027] The search mode may include an awake mode for the
communication device. In other embodiments, the search mode may
include a mode in which a power management module of the
communication device is awakened while other components of the
communication device remain in a sleep mode.
[0028] In various embodiments, the communication device may be
configured to initiate network operations on the network present at
the communication port, and to determine whether network operations
have ceased, and if so, returning the communication device to the
sleep mode. The communication device may be further configured to
return to the sleep mode, and further to return to the search mode
after it has been in the sleep mode for a predetermined period of
time.
[0029] The communication device may be further configured to
determine whether network operations have ceased, and if so, to
return the communication device to the search mode. The sleep mode
may include turning off some or all of the plurality of electronic
components to reduce the amount of energy drawn from a power supply
of the communication device.
[0030] Other features and aspects of the disclosed technology will
become apparent from the following detailed description, taken in
conjunction with the accompanying drawings, which illustrate, by
way of example, the features in accordance with embodiments of the
disclosed technology. The summary is not intended to limit the
scope of any inventions described herein, which are defined solely
by the claims attached hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The technology disclosed herein, in accordance with one or
more various embodiments, is described in detail with reference to
the following figures. The drawings are provided for purposes of
illustration only and merely depict typical or example embodiments
of the disclosed technology. These drawings are provided to
facilitate the reader's understanding of the disclosed technology
and shall not be considered limiting of the breadth, scope, or
applicability thereof. It should be noted that for clarity and ease
of illustration these drawings are not necessarily made to
scale.
[0032] FIG. 1 is a diagram illustrating an example of a multimedia
network with which various embodiments of the technology disclosed
herein may be implemented.
[0033] FIG. 2 is a diagram illustrating an example architecture for
a communication module having power management capabilities in
accordance with one embodiment of the technology disclosed
herein.
[0034] FIG. 3 is a diagram illustrating an example of a
communication device with which the technology disclosed herein may
be implemented.
[0035] FIG. 4 is a diagram illustrating another example of a
communication device in accordance with one embodiment of the
technology disclosed herein.
[0036] FIG. 5 is an operational flow diagram illustrating an
example process for power management based the absence or presence
of a connection in accordance with one embodiment of the technology
disclosed herein.
[0037] FIG. 6 is an operational flow diagram illustrating another
example process for power management based the absence or presence
of the connection in accordance with one embodiment of the
technology disclosed herein.
[0038] FIG. 7 is an operational flow diagram illustrating an
example process for network formation in accordance with one
embodiment of the technology disclosed herein.
[0039] FIG. 8 is a diagram illustrating an example of the timing of
a Beacon Phase performed by a network node during network
acquisition in accordance with one embodiment of the technology
disclosed herein.
[0040] FIG. 9 illustrates an example computing module that may be
used in implementing various features of embodiments of the
disclosed technology.
[0041] The figures are not intended to be exhaustive or to limit
the invention to the precise form disclosed. It should be
understood that the invention can be practiced with modification
and alteration, and that the disclosed technology be limited only
by the claims and the equivalents thereof.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0042] Embodiments of the technology disclosed herein are directed
toward devices and methods for providing power management for
communication devices based on the status of a device's connection.
More particularly, the various embodiments of the technology
disclosed herein relate to power management based on the presence
or absence of a physical connection to the device, or based on the
presence or absence of a network attached to the device. Further
embodiments are related toward automatic network detection and
formation.
[0043] Before describing the disclosed systems and methods in
detail, it is useful to describe an example of an environment in
which the disclosed technology can be implemented. The example
network of FIG. 1 is now described for this purpose. The network of
FIG. 1 is one example of a multimedia network implemented in a home
or office. In this example, a wired communications medium 100 is
shown. The wired communications medium might be a coaxial cable
system, a power line system, a fiber optic cable system, an
Ethernet cable system, or other similar communications medium.
Alternatively, the communications medium might be a wireless
transmission system. As one example of a wired communication
medium, with a Multimedia over Coax Alliance (MoCA.RTM.) network,
the communications medium 100 is coaxial cabling deployed within a
residence 101 or other environment. The systems and methods
described herein are often discussed in terms of this example
coaxial network application, however, after reading this
description, one of ordinary skill in the art will understand how
these systems and methods can be implemented in alternative network
applications as well as in environments other than the home.
[0044] The example network of FIG. 1 comprises a plurality of
network nodes 102, 103, 104, 105, 106 in communication according to
a communications protocol. For example, the communications protocol
might conform to a networking standard, such as the well-known MoCA
standard. Nodes in such a network can be associated with a variety
of devices. For example, in a system deployed in a residence 101, a
node may be a network communications module associated with one of
the computers 109 or 110. Such nodes allow the computers 109, 110
to communicate on the communications medium 100. Alternatively, a
node may be a module associated with a television 111 to allow the
television to receive and display media streamed from one or more
other network nodes. A node might also be associated with a speaker
or other media playing devices that plays music. A node might also
be associated with a module configured to interface with an
internet or cable service provider 112, for example to provide
Internet access, digital video recording capabilities, media
streaming functions, or network management services to the
residence 101. Also, televisions 107, set-top boxes 108 and other
devices may be configured to include sufficient functionality
integrated therein to communicate directly with the network.
[0045] With the many continued advancements in communications
technology, more and more devices are being introduced in both the
consumer and commercial sectors with advanced communications
capabilities. Many of these devices are equipped with communication
modules that can communicate over the wired network (e.g., over a
MoCA Coaxial Network) as well as modules that can communicate over
fiber or other networks as well. Indeed, in many environments, it
is becoming more commonplace for there to be multiple networks, and
sometimes multiple different networks, across which a user may wish
the network devices to communicate. In such circumstances, network
bridges can be used to allow devices to communicate across multiple
networks.
[0046] Having thus described an example environment in which the
disclosed technology can be implemented, various features and
embodiments of the disclosed technology are now described in
further detail. Description may be provided in terms of this
example environment for ease of discussion and understanding. After
reading the description herein, it will become apparent to one of
ordinary skill in the art that the disclosed technology can be
implemented in any of a number of different communication
environments (including wired or wireless communication
environments) operating with any of a number of different
electronic devices, whether or not according to various similar or
alternative protocols or specifications.
[0047] As noted above, some embodiments of the technology disclosed
herein may be implemented to conduct power management operations
based on the presence or absence of a communication cable connected
to the subject equipment. FIG. 2 is a diagram illustrating an
example architecture for a communication module having power
management capabilities in accordance with one embodiment of the
technology disclosed herein. In the example illustrated in FIG. 2,
the communication device 204 includes power management module 208
and device functional modules 214. Power management module 208
includes a sensing module 210 and a power control module 212.
Sensing module 210 can include the capability detect the presence
or absence of a cable connected to the communication device 204. In
other embodiments, sensing module 210 can include the capability to
detect the presence or absence of a signal on incoming signal
path.
[0048] Device functional modules 214 can include, for example, one
or more electronic components (with or without associated software)
used by communication device 204 in its intended operation. For
example, where communication device 204 is a set-top box, device
functional modules 214 can include, for example, a communications
transceiver, including a transmitter and receiver to transmit and
receive data (e.g., MoCA packets) across a coaxial network, tuners,
a display, display drivers, indicators, GUI generators, DVRs, and
the like. Communication device 204 is not limited to set-top box
applications it can also be applied to adapters, bridges, routers,
and other equipment with networking or communications
capabilities.
[0049] In the illustrated example, communication device 204
includes a port that may include a signal path 215 connected to a
connector 216 such as, for example, an F connector or the like.
Signal path may include, for example, a conductive wire (whether or
not shielded), traces on a printed circuit board, or other
electrical connection between connector 216 and the device
components. As illustrated, connector 216 may be configured to be
connected to a physical communication medium 218 such as, for
example, a coaxial cable (e.g., via a mating connector), which in
turn may be connected to a wall outlet 220. Wall outlet 220 may
connect to a coaxial network or backbone such as, for example,
communications medium 100 as shown in the example of FIG. 1. As
will become apparent to one of ordinary skill in the art after
reading this description, the disclosed technology can be
implemented with a number of different communication interfaces,
and it is not limited to implementation with the exemplary F
connector and coaxial cable.
[0050] Communication device 204 can further include a housing
within which some or all of its components can be mounted
(partially or completely). Interface components such as displays,
indicators and connectors can be mounted at an exterior surface of
the housing so that they can be viewed or accessed easily. A power
supply is typically included with the communication device 204. The
power supply can include, any of a variety of power sources such
as, for example, batteries or capacitor banks (or other energy
storage devices), AC/DC power converters (or other power converters
or inverters, whether AC-to-DC, AC-to-AC, DC-to-DC or DC-to-AC),
generators, photovoltaic cells, and so on. The power supply
(whether or not including related voltage dividers, conditioning
circuits etc.) can be used to supply power to the various
components and modules. Accordingly, the various components and
modules may be coupled to draw energy directly or indirectly from
the power supply.
[0051] Having thus presented an example architecture for a
communication device 204, an example of its operation is now
described in terms of this example architecture. In operation,
sensing module 210 can be implemented to detect the presence or
absence of a cable 218 connected to connector 216. Sensing module
210 may be configured to communicate the result of this detection
to power control module 212. For example, where sensing module 210
detects the absence of cable 218, it communicates this information
to power control module 212.
[0052] Upon receipt of this information, power control module 212
may be configured to transition the communication device 204 into a
sleep mode. That is power control module 212 can be configured to
reduce power of communication device 204 to save energy. In various
embodiments, one or more components of communication device 204 can
be powered down or transitioned to a low-power state to reduce the
overall power consumed by the unit. A low-power state can comprise
a state in which the component consumes less power than if it were
to remain in its normal operational state. Power control module 212
may be configured to reduce power of the device in accordance with
a predetermined methodology. However, in other embodiments, power
control module 212 may be configured to determine a number of
power-down factors such as, for example, which of a plurality of
components to power down, the degree or extent to which such
selected components should be powered down, the length of time for
which the components should be powered down (or in a reduced-power
state) and so on. Such determinations can be made, for example,
based on the functions performed by communication device 204,
components related to those functions and other factors. As a
further example, Energy Star requirements may dictate the extent to
which one or more components of the communication device 204 are
powered down.
[0053] Determinations can also be made based on the amount of time
required to return communication device 204 to an operational state
upon power up, and the speed with which this must occur based on
the communication requirements or specifications of the
communication device 204. For example, if communication device 204
is part of a high-priority communication system in which delay or
latency cannot be tolerated, components that take an unduly long
time to power back up (e.g., longer than the amount of time that
would be permitted to allow the communication device 204 to return
to operation and meet a given specification) might not be powered
down, or might only be partially powered down (so that they don't
take as long to return to their operational state). This
determination can be preconfigured for a given device or
application, or may be determined on a case-by-case basis by the
unit depending on the application of the unit, the importance or
priority of a given communication flow with which it is operating,
and so on.
[0054] Power control module 212 may further be configured to limit
the amount of time that the unit or portions thereof are in
power-down mode. For example, the system may be configured to enter
a power-down or sleep mode, yet continue to operate sensing module
210 to continue to sense for a connection. When the connection
returns (whether a physical connection, signal, or other indicia of
returning service, depending on the embodiment) this can be
communicated to power control module 212, which can, in turn, begin
to return the device functional modules 214 to the on state. In
other embodiments, a timer can be set and configured such that
regardless of the absence or presence of the connection, the unit
is powered back up to its fully operational mode (or partially
operational in some embodiments, depending on the application) when
the predetermined amount of time has elapsed. In further
embodiments, sensing module 210 may be configured to sense
continuously or regularly upon the initiation of the power-down
mode, while in other embodiments, sensing module 210 may be
configured to also enter a sleep mode (partially or fully power
down) for a predetermined period of time upon detecting the absence
of the connection.
[0055] In addition to or instead of checking for the presence of a
cable or other physical connection, embodiments may also be
implemented in which sensing module 210 is configured to detect the
presence or absence of a network service on a communication link.
For example, sensing module 210 can be configured to look for the
absence or presence of a signal at the communications interface
(whether wired or wireless), which information can be used to
trigger the power-savings mode. Various techniques can be used to
detect the absence or presence of a network service, examples of
which are described in further detail below.
[0056] There are a number of techniques that can be used to
determine the presence or absence of a connection in accordance
with various embodiments. For example, where sensing module 210 is
configured to determine whether a cable is connected to the device,
it can be configured to measure signal characteristics on signal
path 215 (which may itself indicate whether a cable is connected to
the device). As a further example, in one embodiment, the system
can be configured to simply detect the presence or absence of a
signal on signal path 215. In further embodiments, the system can
be configured to check for particular signal characteristics of a
signal that may be present on the signal path. That is, in some
embodiments, the system can be configured to check for particular
network communications (e.g., the presence of network beacons) on
signal path 215.
[0057] The system may also be configured to launch a probe signal
onto signal path 215 and detect and measure the results of that
launched signal. Such a probe signal may be launched, for example,
by sensing module 210, or by one of the device functional modules
214. Cable presence circuits can be included with sensing module
210 to determine whether the cable is connected or not by, for
example, measuring the resulting voltage or current at the port due
to the test signal, comparing the measured value with a reference
value and, based on the outcome of the comparison, deciding whether
an external cable is mated to the device or not. For example,
signal characteristics can be measured at the center pin or sensed
at a filter connected as part of signal path 215. As a further
example, the phase or amplitude, or both, of the signal may be
measured to determine whether a cable 218 (and ultimately the
network) is connected to connector 216.
[0058] In various embodiments, the reference values may be trained
by characterization and stored, or the reference values may be
configured by design of the unit. For example, the communication
device 204 may be characterized during design to establish a
characterization of the phase and amplitude of a launched signal
for connected and opened configurations.
[0059] In some embodiments, the test signal may include a signal
that is swept over a frequency range such that measured results can
be compared to their corresponding references at various
frequencies. For example, the system can be configured to compare
the energy at one or more frequencies with reference energy values
corresponding to those frequencies to determine whether a cable is
present.
[0060] In further embodiments, the test signal can be configured to
be a low-level signal or of short duration to minimize the
potential interference that may be induced on signal path 215 (and
potentially onto the network) in the event that the cable is
connected. For example, the system may be configured to
intermittently launch a short duration signal to detect the
presence or absence of a connection, and then wait for a
predetermined period of time before launching another signal. It is
noted that there may be a trade-off between recovery time and the
sampling period. For example, if a fast recovery is needed based on
system requirements, the system may be configured to sample or
probe more frequently.
[0061] FIG. 3 is a diagram illustrating an example of a piece of a
communications module with which the technology disclosed herein
may be implemented. After reading this description, one of ordinary
skill in the art will appreciate that the technology disclosed
herein can be used with any of a number of different devices or
equipment having communication capabilities.
[0062] With reference now to FIG. 3, in this example application,
the example communication device 204 includes sensing module 210,
power control module 212, and one or more device functional modules
214. In this example, device functional modules 214 include an I/O
interface module 308, functional modules 338, a control module 336,
and a communication module 334. Communication device 204 also
includes a processor 306 (which can include multiple processors or
processing units), and memory 310 (which can include memory units
or modules of different types). Processor 306 in memory 310 can
also be shared by sensing module 210 and power control module 212,
or these components can include their own processors and memory.
The various components of the communication device 204 are
communicatively coupled via a bus 312 over which these modules may
exchange and share information and other data.
[0063] I/O interface module 308, as provided in the illustrated
example, can be configured to couple communication device 204 to
other network nodes. These can include other network nodes or other
equipment. In some embodiments, I/O interface module 308 comprises
network interface circuitry, which in this example architecture
includes a receiver module 318 and a transmitter module 320. These
can, for example, include a communication receiver and a
communication transmitter for wired or wireless communications
across the network. Accordingly, communications via the I/O
interface module 308 can, for example, be wired network
communications, and the transmitter and receiver contained therein
can include line drivers and receivers, as may be appropriate for
the network communication interfaces. For example, I/O interface
module 308 can be configured to interface with a network such as a
MoCA network or an Ethernet network (although other network
interfaces can be provided) or with a non-network physical
connection. I/O interface module can also be configured to provide
a wireless communication interface (e.g., Bluetooth, Zigbee, IEEE
802.11, and so on) including an antenna or antennas. Transmitter
module 320 may be configured to transmit signals that can include
data, beaconing and other MAC communications, and other
information. These may be sent using a standard network protocol if
desired. Receiver module 318 is configured to receive signals from
other equipment. These signals can likewise include data and other
communications from the other equipment, and can also be received
in a standard network protocol if desired.
[0064] Memory 310, can be made up of one or more modules of one or
more different types of memory, and in the illustrated example is
configured to store data and other information 324 as well as
operational instructions that may be used by the processor to
operate communication device 204. The processor 306, which can be
implemented as one or more cores, CPUs, DSPs, or other processor
units, for example, is configured to execute instructions or
routines and to use the data and information in memory 310 in
conjunction with the instructions to control the operation of the
communication device 204. For example, in the case of a set-top box
program guides or other GUIs can be stored in memory 310 and used
in the operation of communication device 204.
[0065] Other modules can also be provided with the communication
device 204 depending on the equipment's intended function or
purpose. A complete list of various additional components and
modules would be too lengthy to include, however a few examples are
illustrative. For example, a separate communication module 334 can
also be provided for the equipment to manage and control
communications received from other entities, and to direct received
communications as appropriate. Communication module 334 can be
configured to manage communication of various information sent to
and received from other entities. Communication module 334 can be
configured to manage both wired and wireless communications. A
separate control module 336 can be included to control the
operation of communication device 204. For example, control module
336 can be configured to implement the features and functionality
of communication device 204. Functional modules 338 can also be
included to provide other equipment functionality. For example, in
the case of a set-top box, these modules (which may include various
forms of hardware and software) can be provided to receive program
content, decode received program content, convert the decoded
content to an acceptable form for playback, and so on. As these
examples illustrate, one of ordinary skill in the art will
appreciate how other modules and components can be included with
communication device 204 depending on the purpose or objectives of
the equipment.
[0066] FIG. 4 is a diagram illustrating another example of a
communication device in accordance with one embodiment of the
technology disclosed herein. The example in FIG. 4 includes a
network node 400 connected to a set-top box 412. In the example
illustrated in FIG. 4, the node 400 is a MoCA node that includes a
physical layer (PHY layer) 403, and a media access control layer
(MAC layer) 406. In other embodiments, node 400 can be a network
node for other networks including a WiFi network (IEEE 802.11) or
other local area or wide area network.
[0067] PHY layer 403 can be included with network node 400 to
provide communications over a communications medium such as, for
example, a coaxial cable 404 (used as the medium for a MoCA
network), an Ethernet cable, a wireless interface, and so on. PHY
layer 403 can be used to provide modulation and demodulation of
signals for transmission over the communications medium. As
illustrated PHY layer 403 is communicatively coupled to MAC layer
406. MAC layer 406 can be used to determine the content and timing
of transmissions over the communication network (e.g., the MoCA
network). In the illustrated example, MAC layer 106 includes a
processor 408 and a memory 410. In various embodiments, processor
408 is responsible for performing the functions of MAC layer 406,
and communicates with memory 410 to both retrieve instructions for
execution of the processor functions, and also to store information
necessary to the functions of the processor 408.
[0068] In the illustrated example, node 400 is coupled to a device,
such as a set-top box 412. The node 400 can be configured to allow
the set-top box 412 to communicate with other network nodes such
as, for example, other set-top boxes, DVR's, computers, and so on,
over the network. In other embodiments, node 400 can be included
within set-top box 412, or within another network device.
Accordingly, MAC layer functionality can be performed by a
processor that also performs a set-top box functions.
Alternatively, set-top box functions and MAC layer functions can be
performed by independent processors. In terms of the example
illustrated in FIG. 3, the functionality of both network node 400
and set-top box 412 can be included in communication device
204.
[0069] As noted above, the timing and content of the signals are
generated and controlled by MAC layer 406. The signals transmitted
over the network are generated by the PHY layer 403. One of
ordinary skill in the art will typically understand the division of
functionality between a PHY layer 403 and in MAC layer 406.
[0070] As described above, in various embodiments, a communication
device (e.g. communication device 204) can be provided with
features and functionality to perform power management operations
based on the device's connectivity with a network or other
communications interface. FIG. 5 is an operational flow diagram
illustrating an example process for power management based the
absence or presence of a connection in accordance with one
embodiment of the technology disclosed herein. FIG. 6 is an
operational flow diagram illustrating another example process for
power management based the absence or presence of the connection in
accordance with one embodiment of the technology disclosed herein.
Particularly, the FIG. 5 illustrates an example of managing power
based on the absence or presence of port connectivity, while FIG. 6
illustrates an example of managing power based on the absence or
presence of a communication network. FIGS. 5 and 6 are now
described in terms of the example communication device 204
introduced above. After reading this description, one of ordinary
skill in the art will understand how these processes can be
implemented with other communication devices.
[0071] Referring now to FIG. 5, at operation 502, the device is
configured to probe a communication port. For example, sensing
module 210 can probe the communication port associated with
connector 216 to determine whether a mating connector/cable is
connected to connector 216, or to determine whether a signal is
present. At operation 506, the device determines whether there is a
connection. At this step, the device (e.g., sensing module 210) can
be configured in any of a number of different embodiments to
determine, for example, whether a cable or network is connected to
the port or whether the appropriate signal is present at the
port.
[0072] If there is no connection, and the system is not yet powered
down, the system initiates power-down operations to power down, or
reduce the power of, selected components. This is illustrated at
operations 509 and 512. If the system was already in a powered-down
mode, this powered-down mode is maintained at operation 512.
[0073] At operation 515 the system can continue monitoring the port
to determine whether a connection is established as illustrated by
operation 515. The monitoring can be performed on a periodic basis
as noted above. At this point, power management components (e.g.
sensing module 210 and power control module 212) may remain awake.
In other embodiments, power management components (e.g. sensing
module 210 and power control module 212) may be powered down along
with the functional modules of the communication device. If the
presence sensing components (e.g. sensing module 210 of power
management module 208) are powered down, at the next probing event
they are powered back on for sensing. If during further probing
iterations the connection continues to be absent, the device
remains in the powered down mode, but can continue periodic
monitoring. The sensing modules may be configured to periodically
awaken from the sleep mode at least long enough to determine
whether an external cable is mated to the connector, or whether the
port is otherwise connected. Accordingly, in embodiments where the
sensing modules are powered down as well, the sensing modules can
be toggled between a sensing mode and a sleep mode to conserve
power when not checking the connection.
[0074] If the system is currently powered, and the device
determines that there is a connection (operations 506, 509), power
is maintained. If, on the other hand, the system is in a
powered-down mode and the device determines at operation 506 that
there is a connection, power is restored to the affected
components. This is illustrated by operations 509 and 522. In some
embodiments, the operational status of the device can be confirmed
to determine whether power should be maintained at the affected
components. Accordingly, at operation 525, the device can be
configured to initiate an acquisition process or otherwise attempt
to connect to the network (or other communication link at the
port). If the acquisition is successful or the device is otherwise
confirmed operational as illustrated at 527, power is maintained as
illustrated at operation 530. The powered device can continue
monitoring for connections to determine whether power should be
maintained or powered down. This is illustrated by operation
532.
[0075] On the other hand, if at operation 527 the acquisition is
not successful or the device is not otherwise confirmed
operational, the device may be returned to a powered-down mode and
monitoring continued. This is illustrated by operational flow path
528, and operations 512 and 515.
[0076] Referring now to FIG. 6, an example method for checking for
a connection based on network detection is now described. At
operation 632, in this example the device wakes from a sleep mode,
or low-power mode and enters a search mode to search for the
presence of a network. In the sleep mode or low-power mode, the
device may be powered down or in a mode with power consumption
reduced or minimized. In the search mode, power is returned to the
device so it can search for the presence of a network and one or
more communication interfaces. In various embodiments, different
levels of power may be applied to the device in the search mode.
For example, in some embodiments, only those components necessary
for searching (e.g. power management module 208 or sensing module
210) are powered on during search mode, while in other embodiments
additional components or even the entire device are powered on in
the search mode.
[0077] At operation 634, while in the search mode, the device
searches for the presence of a recognizable network. In some
embodiments, this can be done, for example, by a sensing module
210. The device may be configured to search for network signals in
general, or it may be configured to search for particular signals
or data packets conforming to one or more of a plurality of
acceptable network protocols. For example, in some embodiments, the
system can be configured to search for particular MAC protocol
elements the presence of which would indicate the existence of a
network. In terms of a MoCA network, for example, the system can be
configured to listen for a beacon, which would indicate that there
is a network present. A beacon in the MoCA context is a signal
transmitted by a particular MoCA network node, referred to as the
network coordinator (NC). The system can be configured to listen
for a predetermined time (e.g., for a few beacon cycles during a
listening period), and can further be configured to do so for each
MoCA channel, one at a time. For example, the system can be
configured to listen throughout the search mode or at given times
(e.g., beginning middle or end) of the search mode. The system may
further be configured to listen for a short time that is long
enough to detect a beacon preamble.
[0078] For example, consider the case of the MoCA network in which
50 beacons are sent over a 500 ms period. Sampling for
approximately 100 .mu.s at times spread out over the listening
period enables the system to detect at least one beacon preamble
over the 500 ms period. Examples of this are discussed in more
detail below with reference to FIGS. 7 and 8.
[0079] If a network is detected, power is applied to system
components and network operations are initiated. This is
illustrated by operation 637, 652 and 654. In some embodiments, the
entire communication device is powered up for operation, while in
other embodiments, only those components necessary for
communication across the detected network are powered unless and
until other device operations are required. During operation, the
communication device can be configured to determine whether
operations have ceased and whether it should enter a sleep mode
based on network communication requirements. If network
communications are continuing, power is maintained and the device
continues operate. This is illustrated by operation 656, and
658.
[0080] Once network operations have ceased, the system can be
configured to return to the sleep mode by powering down system
components as illustrated by operational flow line 659 and
operation 642. At operation 642, the system can be configured to
power down the system components used for network operations and
either return to the search mode directly (not shown in FIG. 6), or
wait for a predetermined period of time before returning to the
search mode (operations 644, 646, and 648). In embodiments where
the communication device returns to the search mode directly, power
management module 208 (or power control module 212) can remain
operational to determine whether a network is present while the
remainder of the device is in sleep mode. In an embodiment where
the device waits before returning to the search mode, the power
management module can also return to the sleep mode (although it
does not have to) as well as the remainder of the communication
device. An example of this is illustrated by operations 644, 646,
and 648 in which a timer is set and allowed to elapse before
returning the communication device to the search mode.
[0081] If at operations 634 and 637 no network is detected, the
system may be returned to a sleep state for a period of time and
then again returned to the search mode to search for the presence
of a network. This is illustrated by operations 642, 644, 646, and
648. In this manner, the device can be configured to toggled
between a low-power mode and a search mode to search for the
presence of a network.
[0082] In further embodiments of the systems and methods disclosed
herein a communication device can be configured to form a new
network with one or more other devices. FIG. 7 is an operational
flow diagram illustrating an example process for network formation
in accordance with one embodiment of the technology disclosed
herein. In accordance with this example process, when the device is
powered on it enters into a listening phase. This is illustrated by
operation 701 and 703. The listening phase can be configured to
last for a predetermined period of time, which preferably is enough
time to search for and acquire a beacon. For example, in one
embodiment, the listening phase can be configured to last for 40
seconds, although other time periods are possible.
[0083] During the listening phase, the communication device (e.g.
network node 400) searches for and attempts to acquire a beacon.
The node 400, for example, may begin the search on the last
operating frequency (LOF) used by the node 400 to communicate over
a network. The LOF is a channel defined by the network
specification. Typically, as part of the network protocol, a
network specification will define several channels over which nodes
can communicate with one another (e.g., determine the frequency and
other characteristics associated with channel). For example, a MoCA
network is defined by the MoCA specification published by the
Multimedia over Coax Alliance (MoCA). Several channels are defined
by the MoCA specification for use by MoCA nodes. The particular
group of channels that are used by a particular MoCA network may
depend upon whether the coaxial cabling over which the MoCA nodes
are communicating is also being used to distribute cable television
content or satellite television content.
[0084] After initiating the search on the LOF, the node 400 steps
through the channels available for that node 400 and communicates
in accordance with the network protocol. In one embodiment of the
disclosed technology, the node steps through the channels one at a
time starting from the LOF. After searching the LOF, the node 400
searches the channel with the lowest frequency. The node 400 and
then returns to search the LOF again. Next, the node 400 searches
the next higher frequency. This pattern of bouncing from the LOF to
the next higher channel continues until the channel with the
highest frequency has been searched. At that point, the node 400
will continue the search pattern from the channel with the highest
frequency to channel with the lowest frequency, searching the LOF
in between each other channel. This search pattern will continue
until the node has exhausted the 40 second listening phase or a
network is found. This is illustrated by operation 705.
[0085] If node 400 finds another network (i.e., can acquire a
beacon transmitted by a network coordinator (NC) of another
network), then at operation 707, node 400 exits the network
acquisition process. However, if the node 400 does not find another
network, then node 400 begins a Beacon Phase (BP) as illustrated by
operation 709. During the BP, node 400 transmits beacons over the
network, as well as listens for beacons being transmitted by
another node. If another node is present on the same channel, then
that node will receive the beacon and respond, or node 400 hears
beacons from the other node. In either case, node 400 will have
found another node (operation 711). Alternatively, if node 400
cannot find another node on the same channel and no other node
detects node 400 (operation 711), then the node 400 returns to
operation 703 and once again starts a listening phase to search for
a network (e.g., on all of the available channels in the
network).
[0086] The duration of the listening phase can be selected to be
any duration between the minimum and maximum duration allowed by
the network specification. In accordance with one embodiment of the
disclosed technology, the duration of the listening phase is
determined randomly. That is, the listening time can vary from one
cycle to the next so that it is not the same amount of time each
cycle. The variations can be predetermined based on anticipated
performance of the MAC parameters of the network. In one
embodiment, the minimum duration is the amount of time required to
search each channel at least once. The maximum duration may be
determined as a trade-off between longer times for nodes to find
one another if neither is yet part of a network and greater
likelihood that a node will find a network that exists. That is,
the more time a node remains in listening phase, the more likely it
will be to find an existing network. However, the less time a node
remains in listening phase, the more likely it will be to transmit
a beacon to another node that is searching for an existing network.
Using a random or a varying period of time for the listening phase
listening phase provides a mechanism for offsetting the times when
one node is transmitting beacons and another node is in listening
mode.
[0087] Although this technique can be used for any of a number of
different networks, an example in the context of one particular
network can be useful to illustrate the timing. FIG. 8 is a diagram
illustrating an example of the timing of a Beacon Phase (BP)
performed by a network node 400 during network acquisition in
accordance with one embodiment of the technology disclosed herein.
The BP in this example comprises a random number of beacon phase
cycles 801. FIG. 8 illustrates two such beacon phase cycles 801A,
801B. Each beacon phase cycle comprises a first listening period
803 during which node 400 listens to the LOF channel to detect any
other nodes that might be active on the channel. In accordance with
one embodiment of the disclosed technology, the listening period
803 has a duration that is variable between 0.1 seconds and 1
second. The particular duration of the listening period 803 is
randomly determined within this range. This can vary from cycle to
cycle according to a predetermined algorithm.
[0088] In one embodiment, node 400 listens during the entire
listening period 803. Alternatively, node 400 only listens for a
limited number of beacon cycles, each of which in this example
embodiment is 10 milliseconds long. In accordance with one such
embodiment, node 400 listens a second time for another limited
number of beacon cycles if the listening period is greater than 0.5
second. The particular number of beacon cycles that the node
listens over the duration of the listening period can vary
depending on the implementation.
[0089] In addition to the listening period 803, each beacon phase
cycle also comprises a plurality of beacon cycles 805. In one
embodiment of the disclosed technology, listening period 803 is a
time such that the first of the beacon cycles 805 begins
immediately after the end of the listening period 803. In one
embodiment, there are 50 beacon cycles, each 10 milliseconds in
duration. During each beacon cycle 805, a beacon 807 is transmitted
followed by an admission control frame (ACF) 809. It should be
noted that the scale of the timing diagram is not necessarily
indicative of the duration of the beacon 807 and the ACF 809.
[0090] After 10 ms, a second beacon cycle 811 starts. The beacon
phase cycle 801A ends when all beacon cycles concluded (50 in the
illustrated example). During the ACF 809, node 400 listens to
determine whether another node has heard the beacon that node 400
sent. If so, then node 400 has found another node (e.g., operation
711). Node 400 may then exit the process (e.g., operation 707).
[0091] In accordance with one embodiment of the disclosed
technology, the number of beacon phase cycles 801 is randomly
selected from a range of N to M, where N is the minimum number of
beacon phase cycles 801 and M is the maximum number of beacon phase
cycles 801. In one embodiment, the minimum N is equal to 100. In
some cases, the network specification may determine the value of
the minimum. In one such embodiment, the maximum number M may be
set to 200. Therefore, the number of beacon phase cycles 801 within
one BP is randomly selected to be a value from 100-200.
[0092] In one embodiment, the value of M may be configured to
depend upon the LOF of node 400. If the LOF of the node is near the
channel at which node 400 begins to search, then the value of M can
be reduced. However, if the LOF is further from the channel that
node 400 begins searching, then the value of M is increased. It
should be noted that the number of beacon phase cycles 801 is
random, no matter what the values of N and M, but that the range of
value from which the number is selected will vary with N and M.
[0093] By making the number of beacon phase cycles 801 random,
nodes that have different LOFs and that power up at approximately
the same time will find each other more rapidly, since the random
number of beacon phase cycles 801 will change the timing of one
node with respect to the other and put them out of synchronization
with one another.
[0094] As used herein, the term module might describe a given unit
of functionality that can be performed in accordance with one or
more embodiments of the technology disclosed herein. As used
herein, a module might be implemented utilizing any form of
hardware, software, or a combination thereof. For example, one or
more processors, controllers, ASICs, PLAs, PALs, CPLDs, FPGAs,
logical components, software routines or other mechanisms might be
implemented to make up a module. In implementation, the various
modules described herein might be implemented as discrete modules
or the functions and features described can be shared in part or in
total among one or more modules. In other words, as would be
apparent to one of ordinary skill in the art after reading this
description, the various features and functionality described
herein may be implemented in any given application and can be
implemented in one or more separate or shared modules in various
combinations and permutations. Even though various features or
elements of functionality may be individually described or claimed
as separate modules, one of ordinary skill in the art will
understand that these features and functionality can be shared
among one or more common software and hardware elements, and such
description shall not require or imply that separate hardware or
software components are used to implement such features or
functionality.
[0095] Where components or modules of the technology are
implemented in whole or in part using software, in one embodiment,
these software elements can be implemented to operate with a
computing or processing module capable of carrying out the
functionality described with respect thereto. One such example
computing module is shown in FIG. 9. Various embodiments are
described in terms of this example-computing module 900. After
reading this description, it will become apparent to a person
skilled in the relevant art how to implement the technology using
other computing modules or architectures.
[0096] Referring now to FIG. 9, computing module 900 may represent,
for example, computing or processing capabilities found within
desktop, laptop and notebook computers; hand-held computing devices
(PDA's, smart phones, cell phones, palmtops, etc.); mainframes,
supercomputers, workstations or servers; or any other type of
special-purpose or general-purpose computing devices as may be
desirable or appropriate for a given application or environment.
Computing module 900 might also represent computing capabilities
embedded within or otherwise available to a given device. For
example, a computing module might be found in other electronic
devices such as, for example, digital cameras, navigation systems,
cellular telephones, portable computing devices, modems, routers,
WAPs, terminals and other electronic devices that might include
some form of processing capability.
[0097] Computing module 900 might include, for example, one or more
processors, controllers, control modules, or other processing
devices, such as a processor 904. Processor 904 might be
implemented using a general-purpose or special-purpose processing
engine such as, for example, a microprocessor, controller, or other
control logic. In the illustrated example, processor 904 is
connected to a bus 902, although any communication medium can be
used to facilitate interaction with other components of computing
module 900 or to communicate externally.
[0098] Computing module 900 might also include one or more memory
modules, simply referred to herein as main memory 908. For example,
preferably random access memory (RAM) or other dynamic memory,
might be used for storing information and instructions to be
executed by processor 904. Main memory 908 might also be used for
storing temporary variables or other intermediate information
during execution of instructions to be executed by processor 904.
Computing module 900 might likewise include a read only memory
("ROM") or other static storage device coupled to bus 902 for
storing static information and instructions for processor 904.
[0099] The computing module 900 might also include one or more
various forms of information storage mechanism 910, which might
include, for example, a media drive 912 and a storage unit
interface 920. The media drive 912 might include a drive or other
mechanism to support fixed or removable storage media 914. For
example, a hard disk drive, a floppy disk drive, a magnetic tape
drive, an optical disk drive, a CD or DVD drive (R or RW), or other
removable or fixed media drive might be provided. Accordingly,
storage media 914 might include, for example, a hard disk, a floppy
disk, magnetic tape, cartridge, optical disk, a CD or DVD, or other
fixed or removable medium that is read by, written to or accessed
by media drive 912. As these examples illustrate, the storage media
914 can include a computer usable storage medium having stored
therein computer software or data.
[0100] In alternative embodiments, information storage mechanism
910 might include other similar instrumentalities for allowing
computer programs or other instructions or data to be loaded into
computing module 900. Such instrumentalities might include, for
example, a fixed or removable storage unit 922 and an interface
920. Examples of such storage units 922 and interfaces 920 can
include a program cartridge and cartridge interface, a removable
memory (for example, a flash memory or other removable memory
module) and memory slot, a PCMCIA slot and card, and other fixed or
removable storage units 922 and interfaces 920 that allow software
and data to be transferred from the storage unit 922 to computing
module 900.
[0101] Computing module 900 might also include a communications
interface 924. Communications interface 924 might be used to allow
software and data to be transferred between computing module 900
and external devices. Examples of communications interface 924
might include a modem or softmodem, a network interface (such as an
Ethernet, network interface card, WiMedia, IEEE 802.XX or other
interface), a communications port (such as for example, a USB port,
IR port, RS232 port Bluetooth.RTM. interface, or other port), or
other communications interface. Software and data transferred via
communications interface 924 might typically be carried on signals,
which can be electronic, electromagnetic (which includes optical)
or other signals capable of being exchanged by a given
communications interface 924. These signals might be provided to
communications interface 924 via a channel 928. This channel 928
might carry signals and might be implemented using a wired or
wireless communication medium. Some examples of a channel might
include a phone line, a cellular link, an RF link, an optical link,
a network interface, a local or wide area network, and other wired
or wireless communications channels.
[0102] In this document, the terms "computer program medium" and
"computer usable medium" are used to generally refer to media such
as, for example, main memory 908, storage unit 920, storage media
914, and channel 928. These and other various forms of computer
program media or computer usable media may be involved in carrying
one or more sequences of one or more instructions to a processing
device for execution. Such instructions embodied on the medium, are
generally referred to as "computer program code" or a "computer
program product" (which may be grouped in the form of computer
programs or other groupings). When executed, such instructions
might enable the computing module 900 to perform features or
functions of the disclosed technology as discussed herein.
[0103] While various embodiments of the disclosed technology have
been described above, it should be understood that they have been
presented by way of example only, and not of limitation. Likewise,
the various diagrams may depict an example architectural or other
configuration for the disclosed technology, which is done to aid in
understanding the features and functionality that can be included
in the disclosed technology. The disclosed technology is not
restricted to the illustrated example architectures or
configurations, but the desired features can be implemented using a
variety of alternative architectures and configurations. Indeed, it
will be apparent to one of skill in the art how alternative
functional, logical or physical partitioning and configurations can
be implemented to implement the desired features of the technology
disclosed herein. Also, a multitude of different constituent module
names other than those depicted herein can be applied to the
various partitions. Additionally, with regard to flow diagrams,
operational descriptions and method claims, the order in which the
steps are presented herein shall not mandate that various
embodiments be implemented to perform the recited functionality in
the same order unless the context dictates otherwise.
[0104] Although the disclosed technology is described above in
terms of various exemplary embodiments and implementations, it
should be understood that the various features, aspects and
functionality described in one or more of the individual
embodiments are not limited in their applicability to the
particular embodiment with which they are described, but instead
can be applied, alone or in various combinations, to one or more of
the other embodiments of the disclosed technology, whether or not
such embodiments are described and whether or not such features are
presented as being a part of a described embodiment. Thus, the
breadth and scope of the technology disclosed herein should not be
limited by any of the above-described exemplary embodiments.
[0105] Terms and phrases used in this document, and variations
thereof, unless otherwise expressly stated, should be construed as
open ended as opposed to limiting. As examples of the foregoing:
the term "including" should be read as meaning "including, without
limitation" or the like; the term "example" is used to provide
exemplary instances of the item in discussion, not an exhaustive or
limiting list thereof; the terms "a" or "an" should be read as
meaning "at least one," "one or more" or the like; and adjectives
such as "conventional," "traditional," "normal," "standard,"
"known" and terms of similar meaning should not be construed as
limiting the item described to a given time period or to an item
available as of a given time, but instead should be read to
encompass conventional, traditional, normal, or standard
technologies that may be available or known now or at any time in
the future. Likewise, where this document refers to technologies
that would be apparent or known to one of ordinary skill in the
art, such technologies encompass those apparent or known to the
skilled artisan now or at any time in the future.
[0106] The presence of broadening words and phrases such as "one or
more," "at least," "but not limited to" or other like phrases in
some instances shall not be read to mean that the narrower case is
intended or required in instances where such broadening phrases may
be absent. The use of the term "module" does not imply that the
components or functionality described or claimed as part of the
module are all configured in a common package. Indeed, any or all
of the various components of a module, whether control logic or
other components, can be combined in a single package or separately
maintained and can further be distributed in multiple groupings or
packages or across multiple locations.
[0107] Additionally, the various embodiments set forth herein are
described in terms of exemplary block diagrams, flow charts and
other illustrations. As will become apparent to one of ordinary
skill in the art after reading this document, the illustrated
embodiments and their various alternatives can be implemented
without confinement to the illustrated examples. For example, block
diagrams and their accompanying description should not be construed
as mandating a particular architecture or configuration.
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