U.S. patent application number 13/756431 was filed with the patent office on 2013-10-24 for system and method of communication using distributed channel access parameters.
This patent application is currently assigned to Qualcomm Incorporated. The applicant listed for this patent is QUALCOMM INCORPORATED. Invention is credited to Santosh Paul Abraham, Alfred Asterjadhi, Simone Merlin, Zhi Quan, Maarten Menzo Wentink.
Application Number | 20130279426 13/756431 |
Document ID | / |
Family ID | 48743870 |
Filed Date | 2013-10-24 |
United States Patent
Application |
20130279426 |
Kind Code |
A1 |
Wentink; Maarten Menzo ; et
al. |
October 24, 2013 |
SYSTEM AND METHOD OF COMMUNICATION USING DISTRIBUTED CHANNEL ACCESS
PARAMETERS
Abstract
A method includes, in response to receiving a delta value of an
enhanced distributed channel access (EDCA) parameter at a station,
determining a value of the EDCA parameter based on the delta value
and based on a base value of the EDCA parameter. The method also
includes, in response to receiving an EDCA parameter set
information element (IE), determining the value of the EDCA
parameter based on the EDCA parameter set IE. The method further
includes, in response to no delta value or EDCA parameter set IE
being received at the station during a time period, setting the
value of the EDCA parameter to a default value of the EDCA
parameter.
Inventors: |
Wentink; Maarten Menzo;
(Breukelen, NL) ; Merlin; Simone; (San Diego,
CA) ; Asterjadhi; Alfred; (San Diego, CA) ;
Quan; Zhi; (Livermore, CA) ; Abraham; Santosh
Paul; (San Diego, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
QUALCOMM INCORPORATED |
San Diego |
CA |
US |
|
|
Assignee: |
Qualcomm Incorporated
San Diego
CA
|
Family ID: |
48743870 |
Appl. No.: |
13/756431 |
Filed: |
January 31, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13672545 |
Nov 8, 2012 |
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13756431 |
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61636382 |
Apr 20, 2012 |
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61661326 |
Jun 18, 2012 |
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61670575 |
Jul 11, 2012 |
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Current U.S.
Class: |
370/329 |
Current CPC
Class: |
Y02D 70/142 20180101;
H04W 74/00 20130101; Y02D 70/23 20180101; H04W 74/0833 20130101;
Y02D 30/70 20200801; H04W 74/08 20130101; H04W 84/18 20130101; H04W
52/0219 20130101 |
Class at
Publication: |
370/329 |
International
Class: |
H04W 74/00 20060101
H04W074/00 |
Claims
1. A method comprising: in response to receiving a delta value of
an enhanced distributed channel access (EDCA) parameter at a
station, determining, using a processor at the station, a value of
the EDCA parameter based on the delta value and based on a base
value of the EDCA parameter; in response to receiving an EDCA
parameter set information element (IE) at the station, determining
the value of the EDCA parameter based on the EDCA parameter set IE;
and in response to no delta value or EDCA parameter set IE being
received at the station during a time period, setting the value of
the EDCA parameter to a default value of the EDCA parameter.
2. The method of claim 1, wherein the EDCA parameter set IE is
received in an association response from an access point or in a
beacon from the access point.
3. The method of claim 1, wherein the time period includes a time
period starting when the station associated with an access
point.
4. The method of claim 1, wherein the delta value comprises a
station specific delta value or a group specific delta value.
5. The method of claim 1, wherein when no EDCA parameter set IE is
received prior to the delta value, the base value of the EDCA
parameter comprises the default value of the EDCA parameter.
6. The method of claim 1, wherein when the EDCA parameter set IE is
received prior to the delta value, the base value of the EDCA
parameter is determined based on the EDCA parameter set IE.
7. The method of claim 1, wherein the default value of the EDCA
parameter complies with an industry standard.
8. The method of claim 7, wherein the industry standard comprises
an Institute of Electrical and Electronics Engineers (IEEE)
802.11ah standard.
9. The method of claim 1, wherein the EDCA parameter comprises a
contention window minimum (CWmin) parameter, a contention window
maximum (CWmax) parameter, an arbitration intra-frame spacing
number (AIFSN) parameter, a transmission opportunity (TXOP) limit
parameter, or any combination thereof.
10. The method of claim 1, wherein the station stores access
category data associated with at least one access category in a
data storage device.
11. The method of claim 10, wherein the at least one access
category comprises a sensor access category, a best efforts access
category, a background access category, a video access category, a
voice access category, or any combination thereof.
12. A device comprising: a processor; and a memory accessible to
the processor, the memory comprising instructions executable by the
processor to: in response to receiving a delta value of an enhanced
distributed channel access (EDCA) parameter, determine a value of
the EDCA parameter based on the delta value and based on a base
value of the EDCA parameter; in response to receiving an EDCA
parameter set information element (IE), determine the value of the
EDCA parameter based on the EDCA parameter set IE; and in response
to no delta value or EDCA parameter set IE being received during a
time period, determine the value of the EDCA parameter to a default
value of the EDCA parameter.
13. The device of claim 12, wherein the EDCA parameter set IE is
received in an association response or in a beacon.
14. The device of claim 12, wherein the EDCA parameter comprises a
contention window minimum (CWmin) parameter, a contention window
maximum (CWmax) parameter, an arbitration intra-frame spacing
number (AIFSN) parameter, a transmission opportunity (TXOP) limit
parameter, or any combination thereof.
15. An apparatus comprising: means for receiving data; and means
for determining a value of an enhanced distributed channel access
(EDCA) parameter, wherein the means for determining is configured
to: responsive to receipt of a delta value of the EDCA parameter,
determine the value of the EDCA parameter based on the delta value
and based on a base value of the EDCA parameter; responsive to
receipt of an EDCA parameter set information element (IE),
determine the value of the EDCA parameter based on the EDCA
parameter set IE; and in response to no delta value or EDCA
parameter set IE being received during a time period, set the value
of the EDCA parameter to a default value of the EDCA parameter.
16. The apparatus of claim 15, wherein the EDCA parameter set IE is
received in an association response or in a beacon.
17. The apparatus of claim 15, wherein the EDCA parameter comprises
a contention window minimum (CWmin) parameter, a contention window
maximum (CWmax) parameter, an arbitration intra-frame spacing
number (AIFSN) parameter, a transmission opportunity (TXOP) limit
parameter, or any combination thereof.
18. A non-transitory storage medium comprising processor-executable
instructions that, when executed by a processor, cause the
processor to: in response to receiving a delta value of an enhanced
distributed channel access (EDCA) parameter at a station, determine
a value of the EDCA parameter based on the delta value and based on
a base value of the EDCA parameter; in response to receiving an
EDCA parameter set information element (IE) at the station,
determine the value of the EDCA parameter based on the EDCA
parameter set IE; and in response to no delta value or EDCA
parameter set IE being received at the station during a time
period, set the value of the EDCA parameter to a default value of
the EDCA parameter.
19. The non-transitory storage medium of claim 18, wherein the EDCA
parameter set IE is received in an association response or in a
beacon.
20. The non-transitory storage medium of claim 18, wherein the EDCA
parameter comprises a contention window minimum (CWmin) parameter,
a contention window maximum (CWmax) parameter, an arbitration
intra-frame spacing number (AIFSN) parameter, a transmission
opportunity (TXOP) limit parameter, or any combination thereof.
Description
I. CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of and claims
priority from U.S. patent application Ser. No. 13/672,545 filed on
Nov. 8, 2012 (which claims priority from U.S. Provisional Patent
Application No. 61/584,698 filed on Jan. 9, 2012, U.S. Provisional
Patent Application No. 61/585,810 filed on Jan. 12, 2012, U.S.
Provisional Patent Application No. 61/636,382 filed on Apr. 20,
2012, U.S. Provisional Patent Application No. 61/661,326 filed on
Jun. 18, 2012, and U.S. Provisional Patent Application No.
61/670,575 filed on Jul. 11, 2012). The present application also
claims priority from U.S. Provisional Patent Application No.
61/636,382 filed on Apr. 20, 2012, U.S. Provisional Patent
Application No. 61/661,326 filed on Jun. 18, 2012, and U.S.
Provisional Patent Application No. 61/670,575 filed on Jul. 11,
2012. Each of the above-identified applications is incorporated
herein by reference in its entirety.
II. FIELD
[0002] The present disclosure is generally related to wirelessly
communicating using distributed channel access parameters.
III. DESCRIPTION OF RELATED ART
[0003] Advances in technology have resulted in smaller and more
powerful computing devices. For example, there currently exist a
variety of portable personal computing devices, including wireless
computing devices, such as portable wireless telephones, personal
digital assistants (PDAs), and paging devices that are small,
lightweight, and easily carried by users. More specifically,
portable wireless telephones, such as cellular telephones and
Internet Protocol (IP) telephones, can communicate voice and data
packets over wireless networks. Many such wireless telephones
incorporate additional devices to provide enhanced functionality
for end users. For example, a wireless telephone can also include a
digital still camera, a digital video camera, a digital recorder,
and an audio file player. Also, such wireless telephones can
execute software applications, such as a web browser application
that can be used to access the Internet. As such, these wireless
telephones can include significant computing capabilities.
[0004] In a wireless network, such as an Institute of Electrical
and Electronics Engineers (IEEE) 802.11ah compliant network,
distributed channel access parameters may be defined to control
access to a transmission medium (e.g., a wireless network) by
devices communicating via the wireless network.
[0005] Distributed channel access parameters may permit high
priority traffic a greater chance of being sent than low priority
traffic. For example, a station transmitting high priority traffic
may wait for less time on average before sending a packet than
another station transmitting low priority traffic. Distributed
channel access parameters prioritize traffic by defining different
contention windows (CW) and different arbitration inter-frame space
(AIFS) values for high priority traffic and low priority traffic.
For example, high priority traffic may have a shorter CW and a
shorter AIFS than lower priority traffic. Levels of priority in the
distributed channel access parameters may be referred to as access
categories (ACs).
[0006] A quality of service (QoS) technique referred to as class of
service (CoS) includes a 3-bit field called a priority code point
(PCP) and may be communicated within a frame header transmitted via
a network compliant with one or more IEEE standards. The PCP
specifies a priority value between zero (0) (e.g., a lowest
priority) and seven (7) (e.g., a highest priority) inclusive that
may be used to differentiate traffic. Access categories (e.g.,
priority levels) may be mapped directly from Ethernet-level class
of service (CoS) priority levels.
IV. SUMMARY
[0007] Systems and methods of wirelessly communicating using
distributed channel access parameters are disclosed. The
distributed channel access parameters described herein may be
adapted for sensor traffic and sensor device activity. In
particular, the described techniques may find application in
Institute of Electrical and Electronics Engineers (IEEE) 802.11ah
compliant devices that have low duty cycles. To illustrate, a
wireless sensor that communicates over an IEEE 802.11ah compliant
network may wake up for a relatively short time period to perform
at least one measurement, communicate a result of the measurement
to a destination, and then sleep for a comparatively long period of
time. Because the wireless sensor may have a low duty cycle (i.e.,
a short "active state" duration), the channel access parameters
associated with sensor traffic may be assigned a high priority to
conserve power of energy-constrained devices (e.g., devices that
operate using a battery power source).
[0008] In a particular embodiment, a sensor access category (SE)
may be assigned a highest priority (e.g., a low arbitration
inter-frame space number (AIFSN) value). Values of contention
windows (e.g., CWmin and CWmax) of the sensor access category (SE)
may also be adjusted to support a large number of station devices
(e.g., sensors). For example, multiple sensors may transmit short
packets having a duty cycle of less than one (1) packet per second
(pkt/sec). Non-sensor access categories may be defined as well. For
example, a best efforts access category (BE) may include best
efforts traffic and background traffic (e.g., the best efforts
traffic and the background traffic may be merged into a single
access category). The best efforts traffic may include web browsing
traffic and the background traffic may include data that is not
user defined (e.g., application update data associated with an
application of a device). As another example, distributed channel
access parameters of a video access category (VI) and a voice
access category (VO) may be defined such that voice traffic
experiences a low access delay and video traffic is transmitted at
a high bit rate.
[0009] The AIFSN value may be associated with prioritizing a
particular access category over another access category (AC). The
AIFSN values may define shortening or expanding of a time period
that a station is to wait between transmitting successive frames. A
shorter wait time period permits a message to have a higher
probability of being transmitted with low latency, which is a
consideration for delay-critical data, such as media data (e.g.,
voice data, video data, or streaming data). An arbitration
inter-frame space (AIFS) value may be defined by a formula:
AIFSN[AC]*ST+SIFS, where AIFSN depends on the access category, ST
is a slot time dependent on a physical layer, and short inter-frame
space (SIFS) is a time between a DATA frame and an acknowledge
(ACK) frame.
[0010] The distributed channel access parameters may correspond to
contention free access to a channel for a period called a transmit
opportunity (TXOP) (e.g., transmission opportunity). The TXOP is a
bounded time interval during which a station may send as many
frames as possible, as long as a duration of a particular
transmission does not extend beyond a maximum duration of the TXOP.
If the particular transmission extends beyond the maximum duration
of the TXOP, the transmission may be divided into multiple
transmissions that do not extend beyond the maximum duration of the
TXOP. The use of TXOPs reduces a problem of low rate stations
acquiring an inordinate amount of channel time that can occur in
legacy IEEE 802.11 distributed coordination function (DCF) media
access control (MAC) networks. A TXOP time interval of zero (0)
indicates the station is limited to a single MAC service data unit
(MSDU) or MAC management protocol data unit (MMPDU).
[0011] The distributed channel access parameters for non-sensor
traffic may be specified to account for different quality of
service (QoS) requirements associated with different types of
traffic. For example, video traffic, voice traffic, best efforts
traffic, and background traffic may each have different QoS
requirements.
[0012] In a particular embodiment, the distributed channel access
parameters may be defined for four access categories. The four
access categories may include a sensor access category (SE) for
sensor traffic, a voice access category (VO) for voice traffic, a
video access category (VI) for video traffic, and a best efforts
access category (BE) for best efforts traffic and background
traffic. A hierarchy of priority of the access categories may
indicate that the sensor traffic has a higher priority as compared
to other traffic types. In a particular embodiment, the distributed
channel access parameters may define a corresponding contention
window minimum (CWmin) value, a corresponding contention window
maximum (CWmax) value, and an arbitration intra-frame spacing
number (AIFSN) value for each access category. In a particular
embodiment, each of the CWmin value, the CWmax value, and the AIFSN
value may be static values.
[0013] In another particular embodiment, a transmission opportunity
(TXOP) (e.g., transmit opportunity) may be defined for multiple
access categories used in an IEEE 802.11ah complaint network. For
example, a TXOP value for a sensor access category (SE) may be
defined as approximately (e.g., .+-.20%) fifteen and six tenths
(15.6) milliseconds (ms) which would allow a particular sensor to
send one packet (e.g., two hundred fifty-six (256) Bytes at one
hundred fifty (150) kilobytes per second (kbps)). TXOP values for a
voice access category (VO) and a video access category (VI) may be
defined based on a scaling factor of ten (10) applied to TXOP
values for the voice access category (VO) and the video access
category (VI) as defined by IEEE 802.11ac. As a further example,
TXOP values for a best efforts access category and a background
access category may be defined as zero (0). In a particular
embodiment, all TXOP values greater than twenty (20) milliseconds
(ms) may be truncated to approximately (e.g., .+-.20%) twenty (20)
milliseconds (ms) to account for at least propagation, channel, and
doppler effect issues.
[0014] In another particular embodiment, transmission opportunity
(TXOP) values defined for multiple access categories used in an
IEEE 802.11 ah complaint network may include TXOP values as defined
by IEEE 802.11 ac. In a particular embodiment, the TXOP values may
include a TXOP value for a sensor access category (SE). For
example, the TXOP value for the sensor access category (SE) may be
zero (0).
[0015] In another embodiment, multiple access categories may be
defined as follows. A highest priority access category may be
specified for Voice and Sensor (VS) applications. A second highest
priority access category may be defined for Video (VI). A third
highest priority access category may be defined as a better than
Best Effort (BBE) category. A lowest priority access category may
be defined as a Best Effort (BE) Category. The resulting set of
Access Categories is VS/VI/BBE/BE. As such, the following Access
Category (AC) structure from highest to lowest with the same or
different order and with various level(s) of priority may include:
VS (Voice/Sensors), VI (Video), BBE (Better than Best Effort), BE
(Best Effort). The AC structure (e.g., SE/VO/VI/BE) provided
throughout in combinations may be augmented with VS/VI/BBE/BE, in
accordance with various embodiments.
[0016] The distributed channel access parameters may be utilized as
default parameters for use in an IEEE 802.11ah network. For
example, an IEEE 802.11ah compliant access point may store the
distributed channel access parameters and may communicate such
parameters to wirelessly connected stations. Thereafter, data
traffic is prioritized based on an access category of such traffic.
For example, sensor traffic (i.e., having a sensor access category
(SE)) may be transmitted at a higher priority than other types of
traffic.
[0017] In a particular embodiment, a method includes, in response
to receiving a delta value of an enhanced distributed channel
access (EDCA) parameter at a station, determining a value of the
EDCA parameter based on the delta value and based on a base value
of the EDCA parameter. The method also includes, in response to
receiving an EDCA parameter set information element (IE) at the
station, determining the value of the EDCA parameter based on the
EDCA parameter set IE. The method further includes, in response to
determining that no delta value or EDCA parameter set IE is
received at the station during a time period, setting the value of
the EDCA parameter to a default value of the EDCA parameter.
[0018] To illustrate, a station may update EDCA parameter(s) as
follows. If no EDCA parameter set or modified EDCA parameter set
(e.g., including one or more delta values) is received during a
particular time period (e.g., a particular number of beacon
intervals, since association of the station with an access point,
etc.), the station may use default value(s) for EDCA parameter(s).
If an EDCA parameter set is received but no modified EDCA parameter
set is received, the station may update its EDCA parameter(s) using
the values in the received EDCA parameter set. If a modified EDCA
parameter set is received, the station may use the modified EDCA
parameter set to determine values for EDCA parameter(s). For
example, the station may add delta value(s) to corresponding base
value(s) for the EDCA parameter(s). The base value(s) may be from
the most recently received EDCA parameter set or may be default
value(s).
[0019] In another particular embodiment, a device includes a
processor and a memory accessible to the processor. The memory
includes instructions executable by the processor to, in response
to receiving a delta value of an EDCA parameter, determine a value
of an EDCA parameter based on a delta value and based on a base
value of the EDCA parameter. The instructions are also executable
by the processor to, in response to receiving an EDCA parameter set
IE, determine a value of the EDCA parameter based on the EDCA
parameter set IE. The instructions are further executable by the
processor to, in response to no delta value or EDCA parameter set
IE being received during a time period, set the value of the EDCA
parameter to a default value of the EDCA parameter.
[0020] In another particular embodiment, an apparatus includes
means for receiving data. The apparatus also includes means for
determining a value of an EDCA parameter. The means for determining
is configured to, responsive to receipt of a delta value of the
EDCA parameter, determine the value of the EDCA parameter based on
the delta value and based on a base value of the EDCA parameter.
The means for determining is also configured to, responsive to
receipt of an EDCA parameter set IE, determine the value of the
EDCA parameter based on the EDCA parameter set IE. The means for
determining is further configured to, responsive to no delta value
or EDCA parameter set IE being received during a time period, set
the value of the EDCA parameter to a default value of the EDCA
parameter.
[0021] In another particular embodiment, a non-transitory storage
medium includes processor-executable instructions that, when
executed by a processor, cause the processor to, in response to
receiving a delta value of an EDCA parameter at a station,
determine a value of the EDCA parameter based on the delta value
and based on a base value of the EDCA parameter. The instructions
are also executable by the processor to cause the processor to, in
response to receiving an EDCA parameter set IE at the station,
determine the value of the EDCA parameter based on the EDCA
parameter set IE. The instructions are further executable by the
processor to cause the processor to, in response to no delta value
or EDCA parameter set IE being received at the station during a
time period, set the value of the EDCA parameter to a default value
of the EDCA parameter.
[0022] One advantage provided by at least one of the embodiments
described herein includes an ability to dynamically determine EDCA
parameters on a per station or per group basis. Another advantage
includes distributed access parameters that account for sensor
traffic (e.g., data traffic associated with a low duty cycle) while
maintaining medium access diversification among multiple access
categories (e.g., multiple traffic types). Another particular
advantage provided by at least one of the embodiments described
herein includes distributed channel access parameters that allow
medium access diversification among multiple access categories
(ACs). A further particular advantage provided by at least one of
the embodiments described herein includes distributed channel
access parameters that conserve power of energy-constrained devices
(e.g., devices that operate using a battery power source such as
devices transmitting sensor traffic).
[0023] Other aspects, advantages, and features of the present
disclosure will become apparent after review of the entire
application, including the following sections: Brief Description of
the Drawings, Detailed Description, and the Claims.
V. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a diagram of a particular embodiment of a system
that is operable to communicate using distributed channel access
parameters;
[0025] FIGS. 2A-2F illustrate particular embodiments of data
structures used to access control data associated with the system
of FIG. 1;
[0026] FIGS. 3A and 3B are graphs illustrating results of
simulations of data transmissions in accordance with various
distributed channel access parameters;
[0027] FIG. 4 is a graph illustrating particular results of
simulations of data transmissions in accordance with various
distributed channel access parameters;
[0028] FIGS. 5A and 5B are graphs illustrating results of
simulations data transmissions in accordance with various
distributed channel access parameters;
[0029] FIG. 6 is a diagram of a particular embodiment of a system
that is operable to communicate using distributed channel access
parameters;
[0030] FIG. 7 is a flow chart of a particular embodiment of a
method of performing communication using distributed channel access
parameters;
[0031] FIG. 8 is a flow chart of a particular embodiment of a
method of transferring distributed access parameters;
[0032] FIG. 9 is a block diagram of a particular embodiment of a
wireless device operable to perform rate control and power control;
and
[0033] FIG. 10 is a diagram of a particular illustrative embodiment
of an enhanced distributed channel access (EDCA) parameter set
information element (IE).
VI. DETAILED DESCRIPTION
[0034] Referring to FIG. 1, a diagram of a particular embodiment of
a system that is operable to communicate in accordance with
distributed channel access parameters is disclosed and generally
designated 100. The system 100 may include an access device 102 and
one or more station (STA) devices 120-126 that communicate 140-146
with the access device 102 via a network 150.
[0035] The access device 102 may include access control data 110
including distributed channel access parameters. The access control
data 110 may define one or more access categories by specifying
distributed channel access parameters for each of the one or more
access categories. The access device 102 may be coupled to at least
one of the station devices 120-126 via the network 150. In a
particular embodiment, the access device 102 may be a wireless
access point (AP).
[0036] The access device 102 may be an access point, a wireless
gateway, a wireless router, a customer premise equipment (CPE)
device, or another device operable to facilitate communication with
the at least one of the station devices 120-126. The access device
102 may include one or more processors and one or more memories as
described herein with respect to FIG. 6. For example, the access
device 102 may include a memory storing the access control data 110
and instructions executable by the processor(s) to perform various
access device 102 functions including transmitting at least a
portion of the access control data 110 to at least one of the
station devices 120-126, as described herein.
[0037] Each of the station (STA) devices 120-126 may include
corresponding access control data 130-136. The access control data
130-136 may specify one or more access categories that each specify
distributed channel access parameters. The access control data
130-136 of each of the station devices 120-126 may be the same
access control data or different access control data. The access
control data 110 of the access device 102 and the access control
data 130-136 of a particular station device 120-126 may be the same
access control data or different access control data.
[0038] The network 150 may be a wireless network (e.g., an
Institute of Electrical and Electronics Engineers (IEEE) 802.11 ah
compliant wireless network) established by the access device 102.
In a particular embodiment, the network 150 may be supported by the
access device 102.
[0039] The station devices 120-126 may each be operable to
communicate wirelessly with the access device 102. For example, the
station devices 120-126 may be a laptop computer (e.g., with a IEEE
802.11 wireless card), a set-top box (e.g., a wireless set-top
box), a personal computer, a tablet computer, a personal digital
assistant (PDA), a CPE device, a multimedia device, a game console,
a sensor, or a mobile phone.
[0040] During operation, the access device 102 may establish
communication with the one or more station devices 120-126 using a
connection routine (e.g., an IEEE 802.11ah compliant connection
routine). Once connected to the access device 102, the station
devices 120-126 may each transmit data to the access device 102 via
the network 150 based at least in part on the access control data
130-136 stored at each device 120-126. The data may include sensor
data, background data, best efforts data, and media data including
audio data (e.g., voice data) and video data. A type of the data
may be predetermined based on a type of the station or may be
determined by an application executing on the station.
[0041] For example, the station device 120 may include the access
control data 130 defining one or more access categories. The one or
more access categories of the access control data 130 may include a
sensor access category specifying distributed channel access
parameters to be used by the station devices 120 to wirelessly
communicate 140 sensor data via the network 150. The one or more
access categories may further include at least one media access
category that specifies distributed channel access parameters to be
used by the station device 120 to wirelessly communicate 140 media
data via the network 150.
[0042] In one embodiment, different devices may use different
access control data based on device, device type (e.g., sensor,
non-sensor, battery operated, mains operated, etc.), membership in
a particular group, type of traffic, or other criteria. In a
particular embodiment, a default value for the access control data
associated with each device type or group (or based on other
criteria) may be defined in an industry standard (e.g., IEEE 802.11
ah) and may be known by all devices that are compliant with the
industry standard. For example, a device to transmit data may be
identified. In a particular embodiment, the device may be
identified based on a device identifier (e.g., an international
mobile subscriber identity, an international mobile equipment
identity, a subscriber identity module identifier, a media access
control address, an electronic serial number, or a combination
thereof), a network address associated with the device, a local
identifier associated with the device, a network identifier
associated with the device, or a combination thereof. Thus, when
the default value is to be used, access control data may not need
to be communicated by an AP to STAs.
[0043] In one embodiment, the station device 120 may indicate to
the access device 102 the device type (e.g., sensor device) and/or
preferred access control data during association/re-association
(e.g., as data in an association/re-association request message).
The access device 102 may successively indicate to each station
device 120-126, a group of station devices 120-126, or one or more
types of station devices 120-126, the access control data by
including the access control data in one or more enhanced
distributed channel access (EDCA) parameter set Information
Elements (IEs). The one or more EDCA parameter set IEs may be sent
during association/re-association (e.g., as data in an
association/re-association response message) or included in a
beacon frame. In one embodiment the EDCA parameter set IE may be
defined in an IEEE 802.11 standard. In another embodiment, the EDCA
parameter set IE may be enhanced from that defined in an IEEE
802.11 standard by appending one or more access control data for
each group of STAs or type of STAs. A particular embodiment of an
EDCA parameter set IE is shown in FIG. 10.
[0044] In another embodiment, the access control data (or a portion
of the access control data) for one or more groups of STAs or types
of STAs may be included as a new field in the beacon frame instead
of being included in an EDCA parameter set IE.
[0045] In one embodiment, the 1 octet reserved field of the EDCA
parameter set IE used in the IEEE 802.11 standard may be used to
identify the type of STA or group of STAs that are going to access
the medium based on the access parameters specified by this access
control data. In another embodiment, a new Information Element may
be defined to store the one or more access control data for one or
more of each of the STAs or type of STAs or group of STAs. One or
more of these EDCA parameter set IEs may be included in the beacon
or may be sent during association/re-association (e.g., in an
association/re-association response message). Hence, different
STAs, groups of STAs, or type of STAs may have different
distributed channel access parameters for each access category.
[0046] In one embodiment, each STA, group of STAs, or type of STAs,
may use the access control data parameters within a given interval
of time. In one embodiment, the interval of time during which the
access control data set for each STA, group of STAs, or type of
STAs, is to be used may be indicated in the beacon, during
association, or may be pre-defined as a multiple of beacons or may
be limited to an interval of time when uplink access is
granted.
[0047] In another embodiment, certain types of STAs may have the
same access parameters for some or all of the access categories. As
an example, a STA of type sensor may have the access parameters
from AC_VO, AC_V.sub.1, AC_BE, and AC_BK set to the same
values.
[0048] In another particular embodiment, all traffic for all user
priorities (UPs) may be sent with the same transmission parameters.
Moreover, traffic from different UPs may be sent in the same
physical layer protocol data unit (PPDU). Further, traffic from
different UPs may use a common sequence number space. It should be
noted that this may differ from existing specifications, where each
traffic identifier (TID)/UP uses a different sequence number space.
The use of a common sequence number space for different TID/UP may
be used by a particular type of STA, upon agreement with the
receiver. The agreement may be indicated though the association
procedure in an association request/response or later through a
dedicated management exchange, such as a modification of the add
block acknowledgement (ADDBA) procedure or traffic specifications
(TSPEC) procedure. The use of the common sequence space across
traffic of multiple TID/UPs may be indicated in each packet (e.g.,
each packet of multiple packets that is transmitted). One bit in a
packet header may indicate that the medium access control (MAC)
service data units (MSDUs) of the packet have a sequence number
from the same space, irrespective of the TID/UP of each for the
MSDUs. This enables use of a single normal Block acknowledgement
(ACK) to acknowledge MSDUs from multiple TIDs/UPs.
[0049] In another particular embodiment, the station device 120 may
include access control data 130 having a particular access category
specifying distributed channel access parameters to be used by the
station device 120 to wirelessly communicate 140 best efforts data
and/or background data. For example, the one or more access
categories may include a single access category for transmission of
best efforts data and background data. In a particular embodiment,
the station device 120 may wirelessly communicate 140 the best
efforts data or the background data.
[0050] In a particular embodiment, the access category data may
indicate that the sensor access category has a higher priority than
other access categories. For example, the access category data may
specify the sensor access category, a media access category, a
voice access category, a video access category, a background access
category, or a combination thereof. The sensor access category may
have a higher priority that the media access category, the video
access category, the voice access category, the background access
category, or a combination thereof. To illustrate, an arbitration
intra-frame spacing number (AIFSN) value associated with the sensor
access category may be lower than an AIFSN value associated with
one or more of the other access categories.
[0051] In a particular embodiment, the channel access parameters
are indicated to each STA individually or to a group of STAs such
that the indication is expressed as a delta relative to a set of
base values that are announced in the beacon. Using the delta
announced in the beacon may enable the AP to modify the parameters
for all STAs or for a group of STAs by changing the base parameters
in the beacon. In a particular embodiment, using the delta
announced in the beacon may enable the AP to modify the parameters
for all STAs or for a group of STAs at once (e.g., concurrently) by
changing the base parameters in the beacon. For example, a base
value of CWmin may be equal to 15 and a STA specific delta may be
equal to 2, indicating that the CWmin at the STA is
((15+1)*2-1)=31. Similarly, a base TXOP limit may be equal to 1
millisecond (ms) and a STA specific delta may be equal to 2,
indicating that the TXOP limit at the STA is equal to (1 ms*2)=2
ms. The use of a base value and STA specific or group specific
delta values may decrease overhead associated with channel access
parameters. For example, instead of communicating changed parameter
values to each of multiple STAs or groups of STAs, an AP may change
the base value once and broadcast the change in a beacon.
[0052] The system 100 of FIG. 1 may thus enable stations
transmitting sensor data to have higher priority, enabling the
sensor data to be favored for access to a transmission medium.
Since sensors may be power constrained (e.g., low power, battery
operated devices, the sensors may be able to save (e.g., conserve)
power by transmitting data without expending additional energy
waiting for access to the transmission medium.
[0053] FIGS. 2A-2F are illustrations of particular embodiments of
data structures 200, 220, 240, 260, 280, and 290 that may be used
to maintain access control data, such as the access control data
110 of the access device 102 and/or the access control data 130-136
of a particular station device 120-126 of FIG. 1. Each data
structure of the data structures 200, 220, 240, 260, 280, and 290
may include at least a portion of another data structure 200, 220,
240, 260, 280, and 290 and/or corresponding values from one of the
other data structures 200, 220, 240, 260, 280, and 290. Each of the
data structures 200, 220, 240, 260, 280, and 290 may be utilized by
the access device 102 or the station devices 120-126 to allow
medium access diversification among multiple access categories
(ACs).
[0054] The data structure 200 of FIG. 2A illustrates a particular
embodiment of representing access control data. The data structure
200 may include a plurality of fields, such as an access category
field 202, a contention window minimum (CWmin) field 204, a
contention window maximum (CWmax) field 206, and an arbitration
intra-frame spacing number (AIFSN) field 208. In a particular
embodiment, the values associated with the CWmin field 204 and the
CWmax field 206 are time slot values.
[0055] As depicted in FIG. 2A, the access categories 202 may
include a plurality of entries, such as one or more access
categories 216-219. The one or more access categories 216-219 may
include a best efforts category 216, a video category 217, a voice
category 218, a sensor category 219, a background category (not
shown), or any combination of categories thereof. In a particular
embodiment, the best efforts category 216 may include the
background category.
[0056] Each of the access categories 216-219 may include a
corresponding minimum contention window value, a corresponding
maximum contention window value, and a corresponding arbitration
intra-frame spacing number (AIFSN) value. For example, the sensor
access category 219 may indicate a minimum contention window value
of seven (7), a maximum contention window value of thirty-one (31),
and an AIFSN value of two (2). Further, the access category data of
data structure 200 may specify the voice access category 218 having
a minimum contention window value of fifteen (15), a maximum
contention window value of thirty-one (31), and an AIFSN value of
four (4). The access category data of data structure 200 may also
specify the video access category 217 having a minimum contention
window value of fifteen (15), a maximum contention window value of
thirty-one (31), and an AIFSN value of five (5). Additionally, the
access category data of data structure 200 may specify the best
efforts access category 216 having a minimum contention window
value of thirty-one (31), a maximum contention window value of one
thousand twenty-three (1023), and an AIFSN value of seven (7).
[0057] The data structure 220 of FIG. 2B illustrates another
particular embodiment of representing access control data. The data
structure 220 may include a plurality of fields such as an access
category field 222, a contention window minimum (CWmin) field 224,
a contention window maximum (CWmax) field 226, an arbitration
intra-frame spacing number (AIFSN) field 228, a transmission
opportunity (TXOP) field 230, or any combination of fields thereof.
The TXOP field 230 may include one or more options such as a first
TXOP option 232 and a second TXOP option 234. The first TXOP option
232 and the second TXOP option 234 are associated with two distinct
and selectable options in which a device, such as the access device
102 or the station devices 120-126 of FIG. 1 may operate.
[0058] As depicted in FIG. 2B, the access categories field 222 may
include a plurality of entries such as one or more access
categories 236-239. For example, the access categories 236-239 may
include a best efforts category 236, a video category 237, a voice
category 238, and a sensor category 239.
[0059] Each of the access categories 236-239 may include a
corresponding minimum contention window value, a corresponding
maximum contention window value, and a corresponding arbitration
intra-frame spacing number (AIFSN) value. For example, the sensor
access category 239 may indicate a minimum contention window value
of seven (7), a maximum contention window value of fifteen (15),
and an AIFSN value of two (2). Further, the access category data of
data structure 200 may specify the voice access category 218 having
a minimum contention window value of seven (7), a maximum
contention window value of thirty-one (31), and an AIFSN value of
four (4). The access category data of data structure 200 may also
specify the video access category 217 having a minimum contention
window value of fifteen (15), a maximum contention window value of
thirty-one (31), and an AIFSN value of five (5). Additionally, the
access category data of data structure 200 may specify the best
efforts access category 216 having a minimum contention window
value of thirty-one (31), a maximum contention window value of one
thousand twenty-three (1023), and an AIFSN value of seven (7).
[0060] Each of the access categories 236-239 may also include at
least one corresponding TXOP value such as a first TXOP value
corresponding to the first TXOP option 232 or a second TXOP value
corresponding to the second TXOP option 234. When a device is
operating in a first TXOP option associated with the first TXOP
option 232, each of the access categories operates in accordance
with the first TXOP values of the first TXOP option 232. For
example, when operating in the first TXOP option, the sensor access
category 239 indicates a first TXOP value is approximately (e.g.,
.+-.20%) fifteen and six tenths (15.6) milliseconds. Further, when
operating in the first TXOP option, the voice access category 238
indicates a first TXOP value is approximately (e.g., .+-.20%)
fifteen and four hundredths (15.04) milliseconds, the video access
category 237 indicates a first TXOP value is approximately (e.g.,
.+-.20%) twenty (20) milliseconds, and the best efforts access
category 236 indicates a first TXOP value is zero (0).
[0061] When the device is operating in a second TXOP option
associated with the second TXOP option 234, each of the access
categories operates in accordance with the second TXOP values of
the second TXOP option 234. For example, when operating in the
second TXOP option, the sensor access category 239 indicates a
first TXOP value is zero (0). Further, when operating in the second
TXOP option, the voice access category 238 indicates a second TXOP
value is approximately (e.g., .+-.20%) one and four hundred four
thousandths (1.504) milliseconds, the video access category 237
indicates a second TXOP value is approximately (e.g., .+-.20%)
three and eight hundredths (3.08) milliseconds, and the best
efforts access category 236 indicates a second TXOP value is zero
(0).
[0062] FIGS. 2C and 2D show alternative embodiments of data
structures 240 and 260 that may indicate user priority (UP) to
access category (AC) mapping. The data structure 240 of FIG. 2C
illustrates a particular embodiment of representing access control
data associated with user priority (UP) to access category (AC)
mapping in which five (5) access categories are defined. Data
structure 240 may include a plurality of fields such as a user
priority (UP) field 244 and an access category (AC) field 246.
[0063] As depicted in FIG. 2C, the access categories field 246 may
include a plurality of entries such as one or more access
categories 250-258. The access categories 250-258 may include a
background category 250, a best efforts category 252, a video
category 254, a voice category 256, and a sensor category 258. The
user priority (UP) field 244 may include a plurality of values that
designate a priority associated with particular types of data. Each
of the access categories may correspond to at least one user
priority (UP) value. For example, the access categories 250-258 may
correspond to the user priority (UP) values as depicted in FIG.
2C.
[0064] The data structure 260 of FIG. 2D illustrates another
particular embodiment of representing access control data
associated with user priority (UP) to access category (AC) mapping
in which four (4) access categories are defined. Data structure 260
may include a plurality of fields, such as a user priority (UP)
field 264 and an access category (AC) field 266.
[0065] As depicted in FIG. 2D, the access categories field 266 may
include a plurality of entries, such as one or more access
categories 268-274. The access categories 268-274 may include a
best efforts category 268, a video category 270, a voice category
272, and a sensor category 274. In a particular embodiment, the
best efforts category 268 may include a background category. For
example, the one or more access categories 268-274 may include a
single access category, such as the best efforts category 268, for
use in transmission of best efforts data and background data.
[0066] The user priority (UP) field 264 may include a plurality of
values that designate priorities of various data types. Each of the
access categories may correspond to at least one user priority (UP)
value. For example, the access categories 268-274 may correspond to
the user priority (UP) values as depicted in FIG. 2D.
[0067] A data structure 280 of FIG. 2E illustrates another
particular embodiment of representing access control data
associated with user priority (UP) to access category (AC) mapping
in which four (4) access categories are defined. The data structure
280 may include a plurality of fields, such as a priority ranking
field 281, a user priority (UP) field 282, an access category (AC)
field 283, and a designation field 284.
[0068] As depicted in FIG. 2E, the access category field 283 may
include a plurality of entries, such as one or more access
categories 285-288. The access categories 285-288 may include a
best efforts category (AC_BE) 285, a video category (AC_VI) 286, a
voice category (AC_VO) 287, and a sensor category (AC_SE) 288. In a
particular embodiment, the best efforts category (AC_BE) 285 may
include a background category. For example, the one or more access
categories 285-288 may include a single access category, such as
the best efforts category (AC_BE) 285, for use in transmission of
best efforts data and background data.
[0069] The user priority (UP) field 282 may include a plurality of
values that designate priorities of various data types. Each of the
access categories 285-288 may correspond to at least one user
priority (UP) value. For example, the best efforts access category
(AC_BE) 285 may correspond to the user priority (UP) values one
(1), two (2), zero (0), and three (3). The video category (AC_VI)
286 may correspond to the user priority (UP) values four (4) and
five (5). The voice category (AC_VO) 287 may correspond to the user
priority (UP) value of six (6) and the sensor category (AC_SE) 288
may correspond to the user priority (UP) value of seven (7).
[0070] A data structure 290 of FIG. 2F illustrates another
particular embodiment of representing access control data
associated with user priority (UP) to access category (AC) mapping
in which five (5) access categories, including separate categories
for background data and best effort data, are defined. The data
structure 290 may include a plurality of fields, such as a priority
ranking field 291, a user priority (UP) field 292, an access
category (AC) field 293, and a designation field 294.
[0071] As depicted in FIG. 2F, the access category field 293 may
include a plurality of entries, such as one or more access
categories 295-299. The access categories 295-299 may include a
background category (AC_BK) 295, a best efforts category (AC_BE)
296, a video category (AC_VI) 297, a voice category (AC_VO) 298,
and a sensor category (AC_SE) 299. The best efforts category
(AC_BE) 296 may be used for transmission of best efforts data and
the background category (AC_BK) 295 may be used for transmission of
background data.
[0072] The user priority (UP) field 292 may include a plurality of
values that designate priorities of various data types. Each of the
access categories 295-299 may correspond to at least one user
priority (UP) value. For example, the background access category
(AC_BK) 295 may correspond to the user priority (UP) values one (1)
and two (2). The best efforts access category (AC_BE) 296 may
correspond to the user priority (UP) values zero (0) and three (3).
The video category (AC_VI) 297 may correspond to the user priority
(UP) values four (4) and five (5). The voice category (AC_VO) 298
may correspond to the user priority (UP) value of six (6) and the
sensor category (AC_SE) 299 may correspond to the user priority
(UP) value of seven (7).
[0073] Each data structure 240, 260, 280, and 290 may be used in
conjunction with either the data structure 200 of FIG. 2A, the data
structure 220 of FIG. 2B, or a combination thereof. Further, the
access category 246 of FIG. 2C, the access category 266 of FIG. 2D,
the access category field 283 of FIG. 2E, and the access category
field 293 of FIG. 2F may correspond to the access category 202 of
FIG. 2A and/or the access category 222 of FIG. 2B. One or more of
the data structures 200, 220, 240, 260, 280, and 290 may be stored
in a memory of the access device 102 and/or a memory of the station
devices 120-126.
[0074] FIGS. 3A, 3B, 4, 5A, and 5B depict various statistical data
representative of a plurality of simulations performed to determine
distributed channel access parameters according to various
embodiments disclosed herein. A simulation setup for each of the
plurality of simulations included defining physical layer
(PHY)/medium access control (MAC) parameters and various traffic
patterns. In particular, FIGS. 3A, 3B, 4, 5A, and 5B were generated
using data gathered over 100 trials in which each trial had a
duration of one (1) minute.
[0075] The defined PHY/MAC parameters included a bandwidth of two
(2) Megahertz (MHZ) and a PHY rate equal to six hundred (600)
kilobytes per second (kbps), a PHY preamble (six (6) symbols)
duration of two hundred forty (240) microseconds (.mu.s), a short
inter-frame space (SIPS) duration of one hundred six (106)
microseconds (.mu.s), and a SLOT duration of forty (40)
microseconds (.mu.s). The defined PHY/MAC parameters further
included a compressed MAC header of twelve (12) bytes, an
acknowledgment ACK of fourteen (14) bytes, a transmission power of
approximately (e.g., .+-.20%) thirty-six and seven tenths (36.7)
milliwatts (mW), and a reception power of approximately (e.g.,
.+-.20%) eleven and four tenths (11.4) milliwatts (mW).
[0076] The defined traffic patterns included voice traffic being
full buffered at two hundred fifty-six (256) Bytes packets, video
traffic being full buffered at one thousand (1000) Bytes packets,
and sensor traffic being a duty cycle (one (1) packet per second
(pkt/s)) at one hundred sixty (160) Bytes packets.
[0077] In a first scenario, graphs 300, 320, and 400 of FIGS. 3A,
3B, and 4 were generated to determine a coexistence of the voice
traffic and the sensor traffic. The first scenario included voice
traffic being full buffered, where a first station device generated
packets of one hundred sixty (160) bytes, which is equivalent to
transmission (TX) duration of approximately (e.g., .+-.20%) two and
six tenths (2.6) milliseconds (ms). The first scenario also
included sensor traffic where all sensors transmitted with a duty
cycle of one (1) packet per second, where all station devices
generated packets of two hundred fifty-six bytes, which is
equivalent to transmission (TX) duration of approximately (e.g.,
.+-.20%) three and eight tenths (3.8) milliseconds (ms), every
second with random start times. Lines plotted on each of the graphs
300, 320, and 400 of FIGS. 3A, 3B, and 4 represent simulations
performed where distributed channel access parameters were defined
for a sensor access category (SE) associated with the sensor
traffic (e.g., sensor data) and for a voice access category (VO)
associated with the voice traffic (e.g., voice data). The defined
values of the distributed channel access parameters for the sensory
access category (SE) and the voice access category (VO) for each of
the plotted lines are indicated in the legends 302, 322, and 402 of
graphs 300, 320, and 400 of FIGS. 3A, 3B, and 4, where the
distributed access parameter for a particular category are listed
between corresponding brackets "[ ]" and represent ["a contention
window minimum (CWmin) value", "a contention window maximum (CWmax)
value", "an arbitration intra-frame spacing number (AIFSN)
value"].
[0078] FIG. 3A is a graphical illustration of sensor traffic based
on a relationship between a plurality of station devices (depicted
along the horizontal axis) and an access delay in milliseconds (ms)
(depicted along the vertical axis) and is generally designated 300.
The access delay was determined as a difference between a
transmission time of a packet and a packet-in-queue availability.
As shown in graph 300, a combination of sensor access category (SE)
values of [7, 31, 2] and voice access category (VO) values of [15,
31, 4] provided a lowest access delay for sensors.
[0079] FIG. 3B is a graphical illustration of voice traffic based
on a relationship between a plurality of station devices (depicted
along the horizontal axis) and a bit rate in kilobits per second
(kbps) (depicted along the vertical axis) and is generally
designated 320. As shown in graph 320, a combination of sensor
access category (SE) values of [7, 15, 2] and voice access category
(VO) values of [7, 31, 4] provided a highest bitrate for voice.
[0080] FIG. 4 is a graphical illustration of sensor traffic based
on a relationship between a plurality of sensor devices (depicted
along the horizontal axis) and an energy consumption for sensor
devices in joules (J) (depicted along the vertical axis) and is
generally designated 400. The energy consumption was associated
with a total amount of energy spent (e.g., consumed) in both
transmission and reception of packets. As shown in graph 400, two
combinations of sensor access category (SE) values and voice access
category (VO) values provided low energy consumption. A first
combination that provided the low energy consumption was sensor
access category (SE) values of [7, 31, 2] and voice access category
(VO) values of [15, 31, 4]. A second combination that provided the
low energy consumption was sensor access category (SE) values of
[15, 31, 2] and voice access category (VO) values of [15, 31,
7].
[0081] As a result of the first scenario, it was determined that
the combination of sensor access category (SE) values of [7, 31, 2]
and voice access category (VO) values of [15, 31, 4] was preferred
because sensor traffic should have a higher priority and be energy
constrained.
[0082] In a second scenario, graphs 500 and 520 of FIGS. 5A and 5B
were generated to determine a coexistence of the voice traffic
(where low access delay is desired) and the video traffic (where
high bitrate is desired). The second scenario included voice
traffic being full buffered and packets of one hundred sixty (160)
bytes, which is equivalent to transmission (TX) duration of
approximately (e.g., .+-.20%) two and six tenths (2.6) milliseconds
(ms). The second scenario also included video traffic being full
buffered and packets of fifteen hundred (1500) bytes, which is
equivalent to transmission (TX) duration of approximately (e.g.,
.+-.20%) twenty (20) milliseconds (ms). Lines plotted on each of
the graphs 500 and 520 of FIGS. 5A and 5B represent simulations
performed where distributed channel access parameters were defined
for a voice access category (VO) associated with the voice traffic
(e.g., voice data) and for a video access category (VI) associated
with the voice traffic (e.g., video data). The defined values of
the distributed channel access parameters for the voice access
category (VO) and the video access category (VI) for each of the
plotted lines are indicated in the legends 502 and 522 of graphs
500 and 520 of FIGS. 5A and 5B, where the distributed access
parameter for a particular category are listed between
corresponding brackets "[ ]" and represent ["a contention window
minimum (CWmin) value", "a contention window maximum (CWmax)
value", "an arbitration intra-frame spacing number (AIFSN) value"].
To determine a coexistence of the voice traffic and the video
traffic, the AIFSN value of the video access category (VI) was
varied to generate the graphs 500 and 520 of FIGS. 5A and 5B.
[0083] FIG. 5A is a graphical illustration of access delay for
voice traffic based on a relationship between AIFSN values for the
voice traffic (depicted along the horizontal axis) and an access
delay in milliseconds (ms) (depicted along the vertical axis) and
is generally designated 500. The access delay was associated with a
difference between a transmission time of a packet and a
packet-in-queue availability. As shown in graph 500, a combination
of sensor access category (SE) values of [7, 31, 2] and voice
access category (VO) values of [15, 31, 4] provided a lowest access
delay for sensors.
[0084] FIG. 5B is a graphical illustration of bitrates for video
traffic based on a relationship between AIFSN values for the voice
traffic (depicted along the horizontal axis) and a bit rate in
kilobits per second (kbps) (depicted along the vertical axis) and
is generally designated 520.
[0085] Voice traffic performed best when video traffic had a lower
access priority. Thus, the second scenario indicates that video
access category (VI) values of [15, 31, 5] allowed for a sufficient
bitrate for transmission of video data. Further, based on the first
scenario and the second scenario, a combination of distributed
channel access parameters were determined including sensor access
category (SE) values of [7, 31, 2], voice access category (VO)
values of [15, 31, 4], video access category (VI) values of [15,
31, 5].
[0086] FIG. 6 is a diagram to illustrate a particular embodiment of
a system 600 to communicate using distributed channel access
parameters. The system 600 may include an access device 610
communicatively coupled to one or more station devices (e.g.,
including an illustrative station device 630) via a network (not
shown). For example the network may be the network 150 of FIG. 1.
In a particular embodiment, the network may be established and/or
supported by the access device 610.
[0087] The access device 610 may include access category data 622
and the station device 630 may include access category data 642. In
an illustrative embodiment, the access device 610 having the access
category data 622 may be the access device 102 and the access
control data 110 of FIG. 1. In addition, the station device 630
having the access category data 642 may be one of the station
devices 120-126 having corresponding access control data 130-136 of
FIG. 1. For example, the station device 630 may be the station
device 120 of FIG. 1.
[0088] The access device 610 may include a transceiver 612, an
antenna 614, a processor 616, a memory 620 accessible to the
processor 616, and transmission opportunity selection logic 626.
The memory 620 may include the access category data 622 specifying
one or more access categories including a sensor access category
specifying distributed channel access parameters for use by one or
more station devices during wireless communication of sensor data
via a network. The memory 620 may further include instructions 624
executable by the processor 616 to send at least a portion of the
access category data 622 to the station device 630 to enable the
station device 630 to communicate sensor data. The memory 620 may
further include instruction 624 executable by the processor 616 to
establish the network with the one or more station devices such as
the station device 630. The transceiver 612 may be operable to
transmit and receive data, such as the access category data 622,
via the antenna 614. For example, the access category data 622 may
be the access control data 110 and 130-136 of FIG. 1, or the data
structures 200, 220, 240, 260, 280, and 290 of FIGS. 2A-F.
[0089] In a particular embodiment, the one or more access
categories of the access category data 622 may include at least one
media access category that specifies distributed channel access
parameters to be used by the station device 630 to wirelessly
communicate media data via the network. The access category data
622 may specify a lower priority for the media data than for the
sensor data. For example, the sensor access category may indicate a
first arbitration intra-frame spacing number (AIFSN) value and the
access category data 622 may include a second AIFSN value for the
at least one media access category, where the first AIFSN value is
lower than the second AIFSN value.
[0090] In another particular embodiment, the one or more access
categories of the access category data 622 may include at least one
voice access category that specifies distributed channel access
parameters to be used by the station device 630 when wirelessly
communicating voice data via the network. For example, the access
category data 622 may specify a lower priority for the voice data
than for the sensor data.
[0091] In a further particular embodiment, the one or more access
categories of the access category data 622 may include at least one
video access category that specifies distributed channel access
parameters to be used by the station device 630 to wirelessly
communicate video data via the network. For example, the access
category data 622 may specify a lower priority for the video data
than for the sensor data.
[0092] The transmission opportunity selection logic 626 may be
operable to select a particular transmission opportunity option
associated with the access category data 622. For example, the
transmission opportunity selection logic 626 may be operable to
select between the first TXOP option 232 and the second TXOP option
234 of data structure 220 of FIG. 2B.
[0093] During operation of the access device 610, the processor 616
may execute application(s) based on the instructions 624 stored in
the memory 620. The processor 616 may also be operable to execute
instructions associated with transmission opportunity selection
logic 626.
[0094] The station device 630 may include a transceiver 632, a
processor 636, a memory 640 accessible by the processor 636, and
transmission opportunity selection logic 638. The transceiver 632
may be coupled to an antenna 634. The transceiver 632 may be
operable to transmit and receive data included in wireless
communication 650 via the antenna 634. The station device 630 may
include an IEEE 802.11ah sensor or other devices having a low duty
cycle and may transmit data to the access device 610, such as
another IEEE 802.11ah device or another non-IEEE 802.11ah
device.
[0095] The memory 640 may include the access category data 642
specifying one or more access categories including a sensor access
category specifying sensor data distributed channel access
parameters to be used during wireless communication of sensor data.
The memory 640 may also include instructions 644 executable by the
processor 636 to wirelessly transmit the sensor data based on
access parameters associated with the sensor access category.
[0096] In a particular embodiment, the one or more access
categories may include at least one media access category that
specifies distributed channel access parameters to be used to
wirelessly communicate media data. For example, the sensor access
category may indicate a first arbitration intra-frame spacing
number (AIFSN) and the access category data 642 may include a
second AIFSN for at least one media access category, where the
first AIFSN is lower than the second AIFSN.
[0097] In another particular embodiment, the one or more access
categories may further include at least one voice access category
that specifies distributed channel access parameters to be used to
wirelessly communicate voice data. The one or more access
categories may further include at least one video access category
that specifies distributed channel access parameters to be used to
wirelessly communicate video data.
[0098] In a particular embodiment, the sensor data distributed
channel access parameters may include a minimum contention window
value of seven (7), a maximum contention window value of thirty-one
(31), and an AIFSN value of two (2). The one or more access
categories may further include a voice access category, a video
access category, and a best efforts/background access category. The
voice access category may specifying voice data distributed channel
access parameters including a minimum contention window value of
fifteen (15), a maximum contention window value of thirty-one (31),
and an AIFSN value of four (4). The video access category
specifying video data distributed channel access parameters
including a minimum contention window value of fifteen (15), a
maximum contention window value of thirty-one (31), and an AIFSN
value of five (5). The best efforts/background access category
specifying best efforts/background data distributed channel access
parameters including a minimum contention window of thirty-one
(31), a maximum contention window of one thousand twenty-three
(1023), and an AIFSN value of seven (7).
[0099] In yet another particular embodiment, the sensor data
distributed channel access parameters may include a minimum
contention window value of seven (7), a maximum contention window
of fifteen (15), and an AIFSN value of two (2). The one or more
access categories may further include a video access category
specifying video data distributed channel access parameters
including a minimum contention window value of fifteen (7), a
maximum contention window value of thirty-one (31), and an AIFSN
value of four (4).
[0100] The transmission opportunity selection logic 638 may be
operable to select a particular transmission opportunity option
associated with the access category data 642. For example, the
transmission opportunity selection logic 638 may be operable to
select between the first TXOP option 232 and the second TXOP option
234 of data structure 220 of FIG. 2B.
[0101] During operation of the access device 610, the processor 616
may execute one or more applications based on the instructions 624
stored in the memory 620. The processor 616 may also be operable to
execute instructions associated with the transmission opportunity
selection logic 626.
[0102] The access device 610 may receive a request (e.g., issue an
association request) from the station device 630 requesting to
establish a wireless connection. The access device 610 may receive
the request via the antenna 614 and the transceiver 612 of the
access device 610. In response to receiving the request, the access
device 610 and the station device 630 may engage in a connection
routine (e.g., an IEEE 802.11ah compliant connection routine).
After successful completion of the connection routine, the wireless
connection may be established between the access device 610 and the
station device 630.
[0103] Prior to, during, or subsequent to the connection routine,
the access device 610 may determine whether the station device 630
includes access category data 642. The access device 610 may
request information associated with the access category data 642
from the station device 630 or the station device may provide the
information as part of the request to establish the wireless
connection. In response to determining that the station device 630
includes the access category data 642, the access device may
further determine whether the access category data 642 of the
station device 630 needs to be update. For example, the access
category data 642 may be the access control data 110 and 130-136 of
FIG. 1 or the data structures 200, 220, 240, 260, 280, and 290 of
FIGS. 2A-F.
[0104] In response to a determination that the station device 630
does not include the access category data 642 or in response to a
determination that the access category data 642 needs to be
updated, the access device 610 may send at least a portion of the
access category data 622 of the access device 610 to the station
device 630. The station device 630 may receive the portion of the
access category data 622 and store the access category data 622 in
the memory 640 of the station device 630 as the access category
data 642.
[0105] In an alternative embodiment, the access device 610 may
automatically transmit the access category data 622 of the access
device 610 to the station device 630 for storage in the memory 640
of the station device 630. When the wireless connection is
established and the station device 630 includes the access category
data 642, the access device 610 and the station device 630 may
communicate data via the wireless connection.
[0106] To send data (e.g., a data packet) from the station device
630 to the access device 610, the station device 630 may determine,
using the access category data 642, distributed channel access
parameters to be applied for a transmission of the data. Prior to
the transmission of the data, the station device 630 may determine
a data type associated with the data to be transmitted. For
example, the station device 630 may determine the data type based
at least in part on an application layer associated with the data
packet. The station device 630 may then determine the distributed
channel parameters to be used for the transmission of the data
based on the determined data type. In a particular embodiment, the
transmission opportunity selection logic 638 of the station device
630 may select one of a plurality of transmission opportunity
(TXOP) options to be used when transmitting the data.
[0107] The station device 630 may wirelessly transmit the data to
the access device 610 using the determined distributed channel
access parameters. The station device 630 may transmit the data via
the transceiver 632 and the antenna 634 of the station device
630.
[0108] In a particular embodiment, the station device 630 may
include a sensor and/or an application to generate sensor data. In
addition to the sensor data, the station device 630 may also
generate another type of data other than sensor data, such as media
data (e.g., voice data, video data, or a combination thereof), best
efforts data, background data, or a combination thereof). The
access category data 642 of the station device 630 may include the
access control data 110 and 130-136 of FIG. 1, the data structures
200, 220, 240, 260, 280, and 290 of FIGS. 2A-F, or a combination
thereof. Data traffic (e.g., the sensor data and data other than
the sensor data) of the station device 630 may be prioritized based
on an access category data type of such data traffic. For example,
sensor traffic (e.g., the sensor data) may be associated with a
sensor access category (e.g., SE or AC_SE) and may be transmitted
at a higher priority than other types of traffic (e.g., data other
than the sensor data). For example, the sensor access category (SE)
may be assigned a highest priority (e.g., a low arbitration
inter-frame space number (AIFSN) value).
[0109] Prior to the transmission of the data, the station device
630 may determine an access category associated with the data to be
transmitted. For example, the access category may be determined
based on a data type associated with the data to be transmitted. In
a particular embodiment, the data type is sensor data and the
access category is a sensor category (e.g., a sensor category
(AC_SE) as in the data structures 200, 220, 240, 260, 280, and 290
of FIGS. 2A-F). The station device 630 may use one or more of the
data structures 200, 220, 240, 260, 280, and 290 of FIGS. 2A-F to
determine one or more parameters for use during transmission of the
data.
[0110] In a first illustrative embodiment, the station device 630
may transmit data using distributed channel access parameters
associated with the data to be transmitted. The station device 630
may determine an access category associated with the data to be
transmitted. For example, the station device 630 may determine the
access category of the data based on a data type associated with
the data to be transmitted. In a particular embodiment, the data
type of the data is a sensor data type. The station device 630 may
access the access category data 642 of the station device 630 to
determine the distributed channel access parameters based on the
access category associated with the data. For example, the access
category data 642 may include one or more of the data structures
200, 220 of FIGS. 2A-B, and the station device 630 may identify the
distributed channel access parameters using one or more of the data
structures 200, 200 of FIGS. 2A-B. The distribution access
parameters may include an arbitration intra-frame spacing number
(AIFSN) value, a CWmin value, a CWmax value, or a combination
thereof. The station device 630 may transmit the data based at
least in part on the identified distributed channel access
parameters associated with the data.
[0111] In a second illustrative embodiment, the station device 630
may transmit data using a transmission opportunity (TXOP) value
associated with the data to be transmitted. For example, the
station device 630 may determine the TXOP value based on an access
category associated with the data to be transmitted. The
transmission opportunity selection logic 638 of the station device
630 may select one of a plurality of transmission opportunity
(TXOP) options to be used when transmitting the data. The station
device 630 may access the access category data 642 of the station
device 630 to identify the TXOP value for the selected TXOP option
based on the access category associated with the data. For example,
the access category data 642 may include the data structure 220 of
FIG. 2B, and the station device 630 may identify the TXOP value of
the data structure 220 of FIG. 2B. The station device 630 may
transmit the data based at least in part on the identified TXOP
value associated with data.
[0112] In a third illustrative embodiment, the station device 630
may transmit data using a user priority (UP) value associated with
the data to be transmitted. For example, the station may determine
the UP value based on an access category associated with the data
to be transmitted. The station device 630 may access the access
category data 642 of the station device 630 to identify the UP
value based on the access category associated with the data. For
example, the access category data 642 may be maintained in one or
more of the data structures 240, 260, 280 of FIGS. 2C-F, and the
station device 630 may identify the UP value based on one or more
of the data structures 240, 260, 280 of FIGS. 2C-F. The station
device 630 may transmit the data based at least in part on the
identified UP value associated with data. For example, when the
station device 630 needs to transmit first data corresponding to
sensor data and second data corresponding to voice data, the
station may determine a first UP value associated with the sensor
data and second UP value associated with the voice data. The
station device 630 may prioritize sending the first data (e.g., the
sensor data) and the second data (e.g., the voice data) based on
the first UP value and the second UP value. In a particular
embodiment, the first UP value of the sensor data has a higher
numerical value than the second UP value of the voice data, where
the higher numerical value indicates that the sensor data has a
higher priority than the voice data.
[0113] Referring to FIG. 7, a flowchart of a particular embodiment
of a method of communicating using distributed channel access
parameters is disclosed and generally designated 700. The method
700 may be performed by a device configured to wirelessly transmit
data. For example, the device may be the access device 102 or the
station devices 120-126 of FIG. 1 or the access device 610 and the
station device 630 of FIG. 6.
[0114] The method 700 may include receiving at least a portion of
access category data, at 702. For example, at least a portion of
access category data may be received from an access device (e.g.,
an access point) before determining distributed channel access
parameters to be used for transmission of first data. The access
category data (or a portion thereof) may include one or more access
categories. The one or more access categories may include at least
one media access category that specifies distributed channel access
parameters to be used to wirelessly communicate media data. For
example, the access category data may be the access control data
110 and 130-136 of FIG. 1, the data structures 200, 220, 240, 260,
280, and 290 of FIGS. 2A-F, or the access category data 622 and 642
of FIG. 6. In a particular embodiment the station device may
receive the access category data from the access device. In another
example the access category data may be received at a time of
construction of the station device.
[0115] The method 700 may include determining a data type of first
data to be transmitted, at 704. The method 700 may also include
determining, using the access category data, distributed channel
access parameters to be used for transmission of the first data
based on an access category assigned to the data type of the first
data, at 706. The access category data specifies one or more access
categories including a sensor access category specifying sensor
data distributed channel access parameters to be used to wirelessly
communicate sensor data. The method 700 may include wirelessly
transmitting the first data using the determined distributed
channel access parameters, at 708.
[0116] The method 700 of FIG. 7 may thus enable a device to
wirelessly transmit data (e.g., sensor data) using (e.g., in
accordance with) distributed channel access parameters having a
sensor access category associated with sensor traffic having a low
duty cycle. The sensor access category associated with sensor
traffic may have a highest priority (e.g., a lowest AIFSN value) as
compared to a plurality of other access categories. By assigning
the sensor access category a lower AIFSN value than the other
access categories, energy consumption may be limited for a device
that transmits sensor data (e.g., sensor traffic).
[0117] Referring to FIG. 8, a flowchart of a particular embodiment
of a method of transferring distributed channel access parameters
is disclosed and generally designated 800. The method 800 may be
performed by a device configured to wirelessly transmit data. For
example, the device may be the access device 102 of FIG. 1, the
station devices 120-126 of FIG. 1, the access device 610 of FIG. 6,
or the station device 630 of FIG. 6.
[0118] The method 800 may include receiving a request from a
station device to establish a wireless connection, at 802. For
example, the station device may be one of the station devices
120-126 of FIG. 1 or the station device 630 of FIG. 6
[0119] The method 800 may include determining whether the station
device includes access control data, at 804. For example, the
access category data may be one of the access control data 110 and
130-136 of FIG. 1, the data structures 200, 220, 240, 260, 280, and
290 of FIGS. 2A-F, or the access category data 622 and 642 of FIG.
6. In response to a determination that the station device does not
include the access control data, the method 800 may advance to 806.
In response to a determination that the station device includes the
access control data, the method 800 may advance to 808.
[0120] Moving to 806, the method 800 may include sending at least a
portion of the access category data to the station device. The
method may then proceed to 808.
[0121] In response to a determination that the station device
includes the access control data, the method 800 may advance to
808. At 808, the method 800 may include establishing the wireless
connection with the station device. For example, the wireless
connection may be established using an IEEE 802.11ah compliant
connection routine.
[0122] The method 800 of FIG. 8 may thus enable a device (e.g., an
access device) to transmit at least a portion of access control
data (e.g., distributed access parameters) to a station device. The
portion of the access control data provided to the station device
may be based on a type of traffic (e.g., a type of data) that the
station device is configured to communicate (e.g., transmit). The
access control data may specify a sensor access category associated
with sensor traffic having a low duty cycle. The sensor access
category may be associated with may have a highest priority (e.g.,
a lowest AIFSN value) for a plurality of access categories. By
assigning the sensor access category a lower AIFSN value than the
other access categories, energy consumption may be limited for the
device.
[0123] Referring to FIG. 9, a block diagram of a particular
embodiment of a wireless device including a processor operable to
communicate using distributed channel access in accordance with the
described embodiments is disclosed and generally designated 900.
The device 900 includes a processor, such as a processor 910,
coupled to a memory 932. The processor 910 may include transmission
opportunity (TXOP) selection logic 912. For example, the TXOP
selection logic 912 may include the transmission opportunity
selection logic 626 and 638 of FIG. 6.
[0124] The memory 932 may be a non-transitory computer readable
storage medium that stores data (e.g., access category data 962),
instructions, or both. For example, the access category data 962
may be one of the access control data 110 and 130-136 of FIG. 1,
the data structures 200, 220, 240, 260, 280, and 290 of FIGS. 2A-F,
or the access category data 622 and 642 of FIG. 6. In a particular
embodiment, the memory 932 may include instructions 952 that may be
executable by the processor 910 to cause the processor 910 to
perform one or more functions of the device 900. For example, the
instructions 952 may include user applications, an operating
system, or other executable instructions, or a combination thereof.
The instructions 952 may be executable by the processor 910 to
cause the processor 910 to perform at least a portion of the
functionality described with respect to any of FIGS. 1 and 6-8. For
example, the instructions 952 may include instructions that are
executable by a computer (e.g., the processor 910) to cause the
computer to perform the method 700 of FIG. 7, the method 800 of
FIG. 8, or a combination thereof.
[0125] In a particular embodiment, the memory 932 includes a
non-transitory computer readable medium including instructions
that, when executed by the processor 910, cause the processor 910
to determine a data type of first data to be transmitted and to
determine, using access category data, distributed channel access
parameters to be used for transmission of the first data based on
an access category assigned to the data type of the first data. The
access category data may specify one or more access categories
including a sensor access category specifying sensor data
distributed channel access parameters to be used to wirelessly
communicate sensor data. In a particular embodiment, the
instructions may further cause the processor to initiate a wireless
transmission of the first data using the determined distributed
channel access parameters. For example, the distributed channel
access parameters may include an arbitration intra-frame spacing
number (AIFSN) value, a CWmin value, a CWmax value, a transmission
opportunity (TXOP) value, a user priority (UP) value, or a
combination thereof, and the processor may initiate a transmission
of the first data in accordance with one or more of the distributed
channel access parameters.
[0126] In another particular embodiment, the memory 932 includes a
non-transitory computer readable medium including instructions
that, when executed by the processor 910, cause the processor to
send at least a portion of the access category data to a station
device to enable the station device to communicate sensor data. The
access category data may specify one or more access categories
including a sensor access category specifying sensor data
distributed channel access parameters to be used to wirelessly
communicate sensor data.
[0127] The device 900 may include a transceiver 950 for sending and
receiving signals and/or data packets. For example, the device 900
may function as a transmitter when the device 900 transmits signals
and/or packets and may function as a receiver when the device 900
receives signals and/or packets.
[0128] FIG. 9 also shows a display controller 926 that may be
coupled to the processor 910 and to a display 928. A coder/decoder
(CODEC) 934 (e.g., an audio and/or voice CODEC) may be coupled to
the processor 910. A speaker 936 and a microphone 938 may be
coupled to the CODEC 934. FIG. 9 also indicates that a wireless
controller 940 may be coupled to the processor 910 and to the
transceiver 950 that is coupled to a wireless antenna 942. In a
particular embodiment, the processor 910, the display controller
926, the memory 932, the CODEC 934, the wireless controller 940,
and the transceiver 950 are included in a system-in-package or
system-on-chip device 922.
[0129] In a particular embodiment, an input device 930 and a power
supply 944 are coupled to the system-on-chip device 922. Moreover,
in a particular embodiment, as illustrated in FIG. 9, the display
928, the input device 930, the speaker 936, the microphone 938, the
wireless antenna 942, and the power supply 944 are external to the
system-on-chip device 922. However, each of the display 928, the
input device 930, the speaker 936, the microphone 938, the wireless
antenna 942, and the power supply 944 can be coupled to a component
of the system-on-chip device 922, such as an interface or a
controller.
[0130] It should be noted that although FIG. 9 depicts a wireless
communications device, the processor 910 and the memory 932 may be
integrated into other devices, such as a multimedia player, an
entertainment unit, a navigation device, a personal digital
assistant (PDA), a fixed location data unit, or a computer (e.g., a
tablet computer, a laptop computer, a desktop computer, etc.), a
media device, a sensor, an access point, a router or gateway
device, or another device configured to wirelessly communicate
data.
[0131] In conjunction with the described embodiments, an apparatus
is disclosed that includes means for receiving at least a portion
of access category data from an access point before determining
distributed channel access parameters to be used for transmission
of first data. For example, the means for receiving may include one
or more of the transceivers 612 and 632 and the antennas 614 and
634 of FIG. 6, the wireless controller 940 and the antenna 942 of
FIG. 9, or any combination thereof.
[0132] The apparatus includes means for determining a data type of
the first data to be transmitted. For example, the means for
determining a data type of first data may include one or more of
the processors 616 and 636 of FIG. 6, the processor 910 of FIG. 9,
or any combination thereof.
[0133] The apparatus includes means for determining, using access
category data, distributed channel access parameters to be used for
transmission of the first data based on an access category assigned
to the data type of the first data. For example, the means for
determining, using access category data, distributed channel access
parameters may include one or more of the processors 616 and 636 of
FIG. 6, the processor 910 of FIG. 9, or any combination
thereof.
[0134] The apparatus also includes means for wirelessly
transmitting the first data using the determined distributed
channel access parameters. For example, the means for transmitting
may include one or more the transceivers 612 and 632 and the
antennas 614 and 634 of FIG. 6, the wireless controller 940 and the
antenna 942 of FIG. 9, or any combination thereof.
[0135] In conjunction with the described embodiments, an apparatus
is disclosed that includes means for receiving a request from a
station device to establish a wireless connection. For example, the
means for receiving may include one or more of the transceivers 612
and 632 and the antennas 614 and 634 of FIG. 6, the wireless
controller 940 and the antenna 942 of FIG. 9, or any combination
thereof.
[0136] The apparatus includes means for determining whether the
station device includes access control data. For example, the means
for determining whether the station device includes access control
data may include one or more of the processors 616 and 636 of FIG.
6, the processor 910 of FIG. 9, or any combination thereof.
[0137] The apparatus includes means for sending at least a portion
of the access category data to the station device. For example, the
means for sending may include one or more of the transceivers 612
and 632 and the antennas 614 and 634 of FIG. 6, the wireless
controller 940 and the antenna 942 of FIG. 9, or any combination
thereof.
[0138] The apparatus also includes means for establishing the
wireless connection with the station device. For example, the means
for establishing may include one or more of the transceivers 612
and 632 and the antennas 614 and 634 of FIG. 6, the wireless
controller 940 and the antenna 942 of FIG. 9, or any combination
thereof.
[0139] In conjunction with the described embodiments, an apparatus
is disclosed that includes means for receiving data. For example,
the means for receiving may include one or more of the transceivers
612 and 632 and the antennas 614 and 634 of FIG. 6, the wireless
controller 940 and the antenna 942 of FIG. 9, or any combination
thereof.
[0140] The apparatus also includes means for determining a value of
an EDCA parameter. The means for determining is configured to,
responsive to receipt of a delta value of the EDCA parameter,
determine the value of the EDCA parameter based on the delta value
and based on a base value of the EDCA parameter. The means for
determining is also configured to, responsive to receipt of an EDCA
parameter set IE, determine the value of the EDCA parameter based
on the EDCA parameter set IE. The means for determining is further
configured to, responsive to no delta value or EDCA parameter set
IE being received during a time period, set the value of the EDCA
parameter to a default value of the EDCA parameter. For example,
the means for determining may include one or more of the processors
616 and 636 of FIG. 6, the processor 910 of FIG. 9, or any
combination thereof.
[0141] Those of skill would further appreciate that the various
illustrative logical blocks, configurations, modules, circuits, and
algorithm steps described in connection with the embodiments
disclosed herein may be implemented as electronic hardware,
computer software, or combinations of both. Various illustrative
components, blocks, configurations, modules, circuits, and steps
have been described above generally in terms of their
functionality. Whether such functionality is implemented as
hardware or software depends upon the particular application and
design constraints imposed on the overall system. Skilled artisans
may implement the described functionality in varying ways for each
particular application, but such implementation decisions should
not be interpreted as causing a departure from the scope of the
present disclosure.
[0142] The steps of a method or algorithm described in connection
with the embodiments disclosed herein may be embodied directly in
hardware, in a software module executed by a processor, or in a
combination of the two. A software module may reside in random
access memory (RAM), flash memory, read-only memory (ROM),
programmable read-only memory (PROM), erasable programmable
read-only memory (EPROM), electrically erasable programmable
read-only memory (EEPROM), registers, hard disk, a removable disk,
a compact disc read-only memory (CD-ROM), or any other form of
non-transitory storage medium. An exemplary storage medium is
coupled to the processor such that the processor can read
information from, and write information to, the storage medium. In
the alternative, the storage medium may be integral to the
processor. The processor and the storage medium may reside in an
application-specific integrated circuit (ASIC). The ASIC may reside
in a computing device or a user terminal (e.g., a mobile phone or a
PDA). In the alternative, the processor and the storage medium may
reside as discrete components in a computing device or user
terminal.
[0143] The previous description of the disclosed embodiments is
provided to enable a person skilled in the art to make or use the
disclosed embodiments. Various modifications to these embodiments
will be readily apparent to those skilled in the art, and the
principles defined herein may be applied to other embodiments
without departing from the scope of the disclosure. Thus, the
present disclosure is not intended to be limited to the embodiments
disclosed herein but is to be accorded the widest scope possible
consistent with the principles and novel features as defined by the
following claims.
* * * * *