U.S. patent application number 14/675858 was filed with the patent office on 2015-07-23 for method and apparatus for selecting a multi-band access point to associate with a multi-band mobile station.
This patent application is currently assigned to InterDigital Technology Corporation. The applicant listed for this patent is InterDigital Technology Corporation. Invention is credited to Arty CHANDRA.
Application Number | 20150208416 14/675858 |
Document ID | / |
Family ID | 37026711 |
Filed Date | 2015-07-23 |
United States Patent
Application |
20150208416 |
Kind Code |
A1 |
CHANDRA; Arty |
July 23, 2015 |
METHOD AND APPARATUS FOR SELECTING A MULTI-BAND ACCESS POINT TO
ASSOCIATE WITH A MULTI-BAND MOBILE STATION
Abstract
A method and apparatus for selecting one of a plurality of
multi-band access points (APs) to associate with a multi-band
wireless transmit/receive unit (WTRU) are disclosed. The multi-band
APs broadcast frequency band information regarding multiple
frequency bands on which the multi-band AP is configured to
operate. The multi-band WTRU selects a particular multi-band AP to
associate with and a frequency band to use to communicate with the
selected multi-band AP based on the frequency band information. If
the multi-band WTRU receives frequency band information from the
selected multi-band AP which indicates that a characteristic,
(e.g., throughput, path loss, load, capacity, backhaul), of the
selected frequency band is unacceptable, the multi-band WTRU
determines whether to disassociate with the selected multi-band AP
or to continue to associate with the selected multi-band AP via a
different frequency band.
Inventors: |
CHANDRA; Arty; (Manhasset
Hills, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
InterDigital Technology Corporation |
Wilmington |
DE |
US |
|
|
Assignee: |
InterDigital Technology
Corporation
Wilmington
DE
|
Family ID: |
37026711 |
Appl. No.: |
14/675858 |
Filed: |
April 1, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13661770 |
Oct 26, 2012 |
9026173 |
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14675858 |
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12880583 |
Sep 13, 2010 |
8301190 |
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13661770 |
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11284242 |
Nov 21, 2005 |
7797018 |
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12880583 |
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60667523 |
Apr 1, 2005 |
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Current U.S.
Class: |
370/329 |
Current CPC
Class: |
H04W 48/08 20130101;
H04L 5/0048 20130101; Y02D 70/22 20180101; H04W 88/10 20130101;
H04W 48/12 20130101; H04W 88/06 20130101; H04W 48/20 20130101; Y02D
70/142 20180101; Y02D 30/70 20200801; H04W 88/08 20130101; H04W
72/0453 20130101 |
International
Class: |
H04W 72/04 20060101
H04W072/04; H04W 76/06 20060101 H04W076/06; H04W 88/06 20060101
H04W088/06; H04W 88/10 20060101 H04W088/10; H04L 5/00 20060101
H04L005/00; H04W 76/02 20060101 H04W076/02 |
Claims
1. A method performed by a multi-band access point (AP),
comprising: receiving a probe request message from a wireless
transmit/receive unit (WTRU), wherein the probe request message
includes first frequency band information; transmitting a probe
response message to the WTRU, wherein the probe response message is
responsive to the probe request message and includes information
regarding a first frequency band and a second frequency band
supported by the multi-band AP; establishing an association with
the WTRU on the first frequency band; transmitting second frequency
band information to the WTRU; and subsequent to transmitting the
second frequency band information, maintaining the association with
the WTRU on the second frequency band or terminating the
association with the WTRU.
2. The method of claim 1, wherein the WTRU is a multi-band
WTRU.
3. The method of claim 1, wherein the first frequency band
information indicates a multi-band capability of the WTRU.
4. The method of claim 1, further comprising: receiving an
association request message from the WTRU; and transmitting an
association response message to the WTRU.
5. The method of claim 1, further comprising: communicating data
with the WTRU on the first frequency band.
6. The method of claim 1, further comprising: determining whether
to maintain the association with the WTRU on the second frequency
band or to terminate the association with the WTRU based on a
quality metric.
7. The method of claim 6, wherein the quality metric is one of:
throughput, path loss, load, capacity, and backhaul.
8. A multi-band access point (AP), comprising: a processor; and a
transceiver in communication with the processor, wherein the
transceiver and the processor are configured to: receive a probe
request message from a wireless transmit/receive unit (WTRU),
wherein the probe request message includes first frequency band
information; transmit a probe response message to the WTRU, wherein
the probe response message is responsive to the probe request
message and includes information regarding a first frequency band
and a second frequency band supported by the multi-band AP;
establish an association with the WTRU on the first frequency band;
transmit second frequency band information to the WTRU; and
subsequent to transmission of the second frequency band
information, maintain the association with the WTRU on the second
frequency band or terminate the association with the WTRU.
9. The multi-band AP of claim 8, wherein the WTRU is a multi-band
WTRU.
10. The multi-band AP of claim 8, wherein the first frequency band
information indicates a multi-band capability of the WTRU.
11. The multi-band AP of claim 8, wherein the transceiver and the
processor are further configured to: receive an association request
message from the WTRU; and transmit an association response message
to the WTRU.
12. The multi-band AP of claim 8, wherein the transceiver and the
processor are further configured to: communicate data with the WTRU
on the first frequency band.
13. The multi-band AP of claim 8, wherein the transceiver and the
processor are further configured to: determine whether to maintain
the association with the WTRU on the second frequency band or to
terminate the association with the WTRU based on a quality
metric.
14. The multi-band AP of claim 13, wherein the quality metric is
one of: throughput, path loss, load, capacity, and backhaul.
15. A multi-band access point (AP), comprising: a processor; and a
transceiver in communication with the processor, wherein the
transceiver and the processor are configured to: receive a probe
request message from a wireless transmit/receive unit (WTRU),
wherein the probe request message includes first frequency band
information; transmit a probe response message to the WTRU, wherein
the probe response message is responsive to the probe request
message and includes information regarding a first frequency band
and a second frequency band supported by the multi-band AP; receive
an association request message from the WTRU; transmit an
association response message to the WTRU; transmit second frequency
band information to the WTRU; and subsequent to transmission of the
second frequency band information, maintain the association with
the WTRU on the second frequency band or terminate the association
with the WTRU.
16. The multi-band AP of claim 15, wherein the WTRU is a multi-band
WTRU.
17. The multi-band AP of claim 15, wherein the first frequency band
information indicates a multi-band capability of the WTRU.
18. The multi-band AP of claim 15, wherein the transceiver and the
processor are further configured to: communicate data with the WTRU
on the first frequency band.
19. The multi-band AP of claim 15, wherein the transceiver and the
processor are further configured to: determine whether to maintain
the association with the WTRU on the second frequency band or to
terminate the association with the WTRU based on a quality
metric.
20. The multi-band AP of claim 19, wherein the quality metric is
one of: throughput, path loss, load, capacity, and backhaul.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a Continuation of U.S. patent
application Ser. No. 13/661,770 filed on Oct. 26, 2012, which is a
Continuation of U.S. patent application Ser. No. 12/880,583 filed
on Sep. 13, 2010 and issued as U.S. Pat. No. 8,301,190 on Oct. 30,
2012, which is a Continuation of U.S. patent application Ser. No.
11/284, 242 filed on Nov. 21, 2005 and issued as U.S. Pat. No.
7,797,018 on Sep. 14, 2010, which in turn claims priority to U.S.
Provisional Patent Application No. 60/667,523 filed Apr. 1, 2005,
the contents of all of which are hereby incorporated by reference
in their entireties.
FIELD OF INVENTION
[0002] The present invention relates to a wireless communication
system including a plurality of multi-band access points (APs) and
a multi-band wireless transmit/receive unit (WTRU), (i.e., a mobile
station). More particularly, the present invention is related to a
method and apparatus for selecting a particular one of the
multi-band APs to associate with based on frequency band
information transmitted from the multi-band APs to the multi-band
WTRU.
BACKGROUND
[0003] A typical wireless local area network (WLAN) includes an AP
which provides radio access to WTRUs in a coverage area of the AP.
The AP is comprised by a basic service set (BSS) which is a basic
building block of an IEEE 802.11-based WLAN. Multiple BSSs may be
interconnected through a distribution system (DS) to form an
extended service set (ESS).
[0004] The WLAN may be configured in an infrastructure mode or an
Ad-hoc mode. In the infrastructure mode, wireless communications
are controlled by an AP. The AP periodically broadcasts beacon
frames to enable WTRUs to identify, and communicate with, the AP.
In the Ad-hoc mode, a plurality of WTRUs operate in a peer-to-peer
communication mode. The WTRUs establish communication among
themselves without the need of coordinating with a network element.
However, an AP may be configured to act as a bridge or router to
another network, such as the Internet.
[0005] The WTRUs and the AP may be configured to utilize multiple
frequency bands for communication. In a conventional wireless
communication system, a multi-band WTRU transmits multiple probe
requests on different channels of a frequency band to discover if
there are any APs available in the area. Once an AP receives the
probe request, it sends a probe response packet to the WTRU. The AP
will send the probe response packet on its operating channel in a
particular frequency band. The probe response packet contains
required parameters, such as supported rate, or the like, for the
WTRU to associate with the AP. The WTRU will send an association
request packet and waits for an association response packet from an
AP for further data communication.
[0006] Once associated, the multi-band WTRU may scan other
frequency bands in search of a better communication band by
transmitting a probe request packet and waiting for a probe
response packet. Upon receiving another probe response packet, the
WTRU compares the frequency bands and/or the AP and selects a more
preferable frequency band and/or AP.
[0007] In the conventional wireless communication system, the
multi-band WTRU must scan and compare different frequency bands to
determine the frequency band that provides the best quality of
wireless communications. However, these scanning and comparison
functions are time-consuming and require a significant amount of
battery power. A method and apparatus for reducing the amount of
time and battery power required to make frequency band and channel
selection decisions is desired.
SUMMARY
[0008] The present invention is related to a method and apparatus
for selecting one of a plurality of multi-band APs to associate
with a multi-band WTRU. The multi-band APs broadcast frequency band
information regarding multiple frequency bands on which the
multi-band AP is configured to operate. The multi-band WTRU selects
a particular multi-band AP to associate with and a frequency band
to use to communicate with the selected multi-band AP based on the
frequency band information. If the multi-band WTRU receives
frequency band information from the selected multi-band AP which
indicates that a characteristic, (e.g., throughput, path loss,
load, capacity, backhaul), of the selected frequency band is
unacceptable, the multi-band WTRU determines whether to
disassociate with the selected multi-band AP or to continue to
associate with the selected multi-band AP via a different frequency
band.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] A more detailed understanding of the invention may be had
from the following description, given by way of example and to be
understood in conjunction with the accompanying drawings
wherein:
[0010] FIG. 1 shows a wireless communication system including a
plurality of multi-band APs and a multi-band WTRU which operate in
accordance with the present invention;
[0011] FIG. 2 is an exemplary beacon frame which comprises
frequency band information transmitted from the multi-band APs to
the multi-band WTRU of the wireless communication system of FIG.
1;
[0012] FIG. 3 is a flow diagram of a process for the multi-band
WTRU to select one of the multi-band APs to associate with in
accordance with the present invention;
[0013] FIG. 4 is a flow diagram of a process for the multi-band
WTRU to determine whether to change a particular frequency band
used for wireless communications with a multi-band AP or to
associate with a different multi-band AP in accordance with the
present invention; and
[0014] FIG. 5 is a flow diagram of a process for establishing a
wireless communication link between the multi-band WTRU and a
preferable multi-band AP over a preferable frequency band in
accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] Hereafter, the terminology "WTRU" includes but is not
limited to a user equipment (UE), a mobile station, a fixed or
mobile subscriber unit, a pager, or any other type of device
capable of operating in a wireless environment. Such WTRUs include,
but are not limited to, phones, video phones, and Internet ready
phones, personal data assistances (PDAs) and notebook computers
with wireless modems that have network capabilities.
[0016] When referred to hereafter, the terminology "AP" includes
but is not limited to a Node-B, a base station, a site controller
or any other type of interfacing device in a wireless environment
that provides other WTRUs with wireless access to a network with
which the AP is associated.
[0017] The features and elements of the present invention may be
implemented on a single IC, (such as an application specific
integrated circuit (ASIC)), multiple ICs, discrete components or a
combination of discrete components and ICs.
[0018] The present invention is applicable to any type of wireless
communication systems including, but not limited to, 802.x-based
wireless communication systems.
[0019] FIG. 1 shows a wireless communication system 100 including a
plurality of multi-band APs 105.sub.1-105.sub.N and a multi-band
WTRU 110 which operate in accordance with the present invention.
Each of the multi-band APs 105.sub.1-105.sub.N and the multi-band
WTRU 110 operate on at least two frequency bands. The multi-band
APs 105.sub.1-105.sub.N transmit frequency band information
115.sub.1-115.sub.N which indicates the different multi-bands that
the respective APs 105.sub.1-105.sub.N are configured to operate
on. Each of the multi-band APs 105.sub.1-105.sub.N include a
respective transceiver 120.sub.1-120.sub.N and a respective
processor 125.sub.1-125.sub.N. Each respective transceiver
120.sub.1-120.sub.N is configured to operate on at least two
different frequency bands. Each respective processor
125.sub.1-125.sub.N generates and formats the respective frequency
band information 115.sub.1-115.sub.N and provides it to the
transceiver 120.sub.1-120.sub.N for transmission. The multi-band
WTRU 110 also includes a transceiver 130 and a processor 135. The
transceiver 130 is configured to operate on at least two different
frequency bands. The processor 135 processes the frequency band
information 115.sub.1-115.sub.N received by the transceiver 130
from the multi-band APs 105.sub.1-105.sub.N, selects a multi-band
AP 105 to associate with, and a frequency band to use in
communication with the selected multi-band AP 105, based on the
frequency band information 115.sub.1-115.sub.N.
[0020] The multi-band WTRU 110 and the multi-band APs
105.sub.1-105.sub.N may use any management, control or data packet
to provide the frequency band information to the multi-band WTRU
110. For example, an authentication frame, (which is a management
frame), can also be used to send multi-band frequency information.
Similarly, this packet can be piggybacked on any of the current or
future WLAN packets.
[0021] Alternatively, a proprietary message exchange between the
multi-band WTRU 110 and the multi-band APs 105.sub.1-105.sub.N may
also be utilized to provide the frequency band information to the
multi-band WTRU 110.
[0022] FIG. 2 shows an exemplary beacon frame which comprises
frequency band information 115 transmitted from each of the
multi-band APs 105.sub.1-105.sub.N to the multi-band WTRU 110 of
the wireless communication system 100 of FIG. 1. The frequency band
information 115 indicates whether a particular multi-band AP 105
supports multiple frequency bands 205.sub.1-205.sub.N, channel
numbers 215 and timing information 220 or the like.
[0023] The frequency band information 115 may further include
quality metric information 210.sub.1-210.sub.N for each of the
frequency bands 205.sub.1-205.sub.N. The quality metric information
may include, but is not limited to, path loss, load, (e.g., the
number of associated WTRUs 110), throughput, capacity and backhaul
on each frequency band.
[0024] FIG. 3 is a flow diagram of a process 300 for establishing a
wireless communication link between a particular one of
115.sub.1-115.sub.N and the multi-band WTRU 110 in the wireless
communication system 100 of FIG. 1 based on frequency band
information 115.sub.1-115.sub.N transmitted from the multi-band APs
105.sub.1-105.sub.N to the multi-band WTRU 110. In step 305, a
plurality of multi-band APs 105.sub.1-105.sub.N broadcast frequency
band information 115.sub.1-115.sub.N regarding multiple frequency
bands on which the respective multi-band AP s 105.sub.1-105.sub.N
are configured to operate. The frequency band information
115.sub.1-115.sub.N may be broadcast in a beacon frame, as shown in
FIG. 2. In step 310, a multi-band WTRU 110 receives and processes
the frequency band information 115.sub.1-115.sub.N. In step 315,
the multi-band WTRU 110 selects a particular one of the multi-band
APs 105.sub.1-105.sub.N to associate with, and a frequency band to
use to communicate with the selected multi-band AP 105 based on the
frequency band information 115.sub.1-115.sub.N.
[0025] FIG. 4 is a flow diagram of a process 400 for the multi-band
WTRU 110 to determine whether to change a particular frequency band
used for wireless communications with a multi-band AP 105, or to
associate with a different multi-band AP 105 in accordance with the
present invention. In step 405, the multi-band WTRU 110 associates
with a particular multi-band AP 105 on a particular frequency band.
In step 410, the multi-band WTRU 110 receives frequency band
information 115 from the particular multi-band AP 105 including a
quality metric which indicates that the particular frequency band
has, for example, poor throughput. In step 415, the multi-band WTRU
110 either disassociates with that the multi-band AP 105 and
associates with another multi-band AP 105 continues to associate
with the same multi-band AP 105 over a different frequency band for
which the frequency band information 115 includes a quality metric
which indicates a good, (i.e., high), throughput.
[0026] FIG. 5 is a flow diagram of a process 500 for establishing a
wireless communication link between the multi-band WTRU and a
preferable multi-band AP over a preferable frequency band in
accordance with the present invention. In step 505, a multi-band
WTRU 110 broadcasts an association request packet or a probe
request packet which is received by a plurality of multi-band APs
105.sub.1-105.sub.N. The multi-band WTRU 110 may include an
indication of the multi-band capability and related information of
the WTRU 110 in the request packet. In step 510, each of the
multi-band APs 105.sub.1-105.sub.N sends an association response
packet or a probe response packet to the multi-band WTRU 110 which
includes frequency band information 115.sub.1-115.sub.N in
accordance with the multi-band capability of the WTRU 110. In step
515, the multi-band WTRU 110 selects a preferable frequency band
and a preferable multi-band AP 105 to associate with based on the
frequency band information 115.sub.1-115.sub.N.
[0027] In another embodiment, the wireless communication system 100
may also include a single-band AP and a single-band WTRU, in
addition to the multi-band APs 105.sub.1-105.sub.N and the
multi-band WTRU 104a. If a single-band WTRU is associated with a
multi-band AP 105, the information regarding the multiple frequency
bands of the multi-band AP 105 other than information regarding the
frequency band on which the single-band WTRU is configured to
operate will be simply ignored by the single-band WTRU since the
single-band WTRU not configured to communicate on multiple
frequency bands. The single-band AP broadcasts its information
regarding its single frequency band, (such as timing, load, or the
like) in a beacon frame. Both a single-band WTRU and a multi-band
WTRU 110 may utilize this information to decide whether or not to
associate with the single-band AP.
[0028] In accordance with the present invention, the multi-band
WTRU 110 is not required to consume significant time and battery
power for scanning various frequency bands in search of an adequate
AP to associate with. Moreover, by providing the multi-band WTRU
110 with quality metrics of each frequency band, (such as
throughput), the WTRU is enabled to optimize not only its own
throughput, but also the throughput of the AP 105.
[0029] Although the features and elements of the present invention
are described in the preferred embodiments in particular
combinations, each feature or element can be used alone without the
other features and elements of the preferred embodiments or in
various combinations with or without other features and elements of
the present invention.
* * * * *