PATENT
`Attorney Docket No. 56162.000497
`GV297
`
`LOCATION AWARENESS IN WIRELESS NETWORKS
`
`FIELD OF THE INVENTION
`
`The present invention relates generally to location awareness in wireless networks and
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`more particularly to identifying and communicating with proximate wireless stations. The
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`present invention also relates generally to communications between stations in wireless networks
`
`5
`
`and more particularly to establishing wireless direct links between proximate stations.
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`BACKGROUND OF THE INVENTION
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`Various wireless standards, such as Institute of Electrical and Electronics Engineers
`
`(IEEE) standards 802.11 a/b/c/e/g/i (referred to collectively as IEEE 802.11 ), provide for wireless
`
`connectivity between a wireless station and an infrastructure network ( e.g., the Internet) via an
`
`10
`
`access point. Processes covered by these standards include the association of a wireless station
`
`with an access point, the transmission of data from wireless station to infrastructure network, and
`
`vice versa, via the access point, communication between wireless stations via an access point,
`
`and the like.
`
`Some wireless standards, such as the direct link protocol (DLP) proposed for inclusion in
`
`15
`
`IEEE 802.11 e, provide a technique for initiating direct communications between wireless
`
`stations without the access point acting as an intermediary for the forwarding the data frames.
`
`The direct communications are commonly referred to as a wireless "direct link." These
`
`conventional direct link processes, however, require active cooperation from the access point in
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`initiating and establishing the direct link. It will be appreciated that the access point may be
`
`20
`
`configured to prevent the establishment of a direct link or may be incapable of supporting direct
`
`link capabilities (e.g., modulation type) preferred by the wireless stations. Wireless stations
`
`using conventional direct link techniques therefore may be unable to establish a direct link or
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`may restricted to establishing and using a direct link with capabilities limited to the supported
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`capabilities of the access point.
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`25
`
`While providing for the establishment of a direct link in limited instances, conventional
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`wireless techniques fail to provide an adequate technique for identifying nearby wireless stations
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`with which a direct link may be established. Further, conventional wireless standards fail to
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`-1 -
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`APPLE 1029
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`

`

`PATENT
`Attorney Docket No. 56162.000497
`GV297
`
`provide processes that allow a wireless user to identify nearby users of wireless stations with
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`whom the wireless user may want to meet or converse.
`
`Accordingly, techniques for establishing a direct link independent of an access point and
`
`for identifying proximate wireless stations users would be advantageous.
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`5
`
`SUMMARY OF THE INVENTION
`
`The present invention mitigates or solves the above-identified limitations in known
`
`solutions, as well as other unspecified deficiencies in known solutions. A number of advantages
`
`associated with the present invention are readily evident to those skilled in the art, including
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`economy of design and resources, transparent operation, cost savings, etc.
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`10
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`Still further features and advantages of the present invention are identified in the ensuing
`
`description, with reference to the drawings identified below.
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`BRIEF DESCRIPTION OF THE DRAWINGS
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`The purpose and advantages of the present invention will be apparent to those of ordinary
`
`skill in the art from the following detailed description in conjunction with the appended drawings
`
`15
`
`in which like reference characters are used to indicate like elements, and in which:
`
`Figure 1 is a top view of an exemplary building having wireless network access provided
`
`by a plurality of access points in accordance with at least one embodiment of the present
`
`invention.
`
`Figure 2 is a schematic diagram illustrating an exemplary wireless station for identifying
`
`20
`
`proximate wireless stations in accordance with at least one embodiment of the present invention.
`
`Figure 3 is a flowchart illustrating an exemplary operation of the wireless station of
`
`Figure 2 in accordance with at least one embodiment of the present invention.
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`Figure 4 is a schematic diagram illustrating an exemplary technique for identifying
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`proximate wireless stations using direct polling in accordance with at least one embodiment of
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`25
`
`the present invention.
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`-2-
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`

`

`PATENT
`Attorney Docket No. 56162.000497
`GV297
`
`Figure 5 is a schematic diagram illustrating an exemplary technique for identifying
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`proximate wireless stations using proximity information maintained by an access point in
`
`accordance with at least one embodiment of the present invention.
`
`Figure 6 is a schematic diagram illustrating an exemplary technique for identifying
`
`5
`
`proximate wireless stations using proximity information maintained by a proximity server
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`associated with an extended service set (ESS) in accordance with at least one embodiment of the
`
`present invention.
`
`Figure 7 is a schematic diagram illustrating an exemplary technique for identifying
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`proximate wireless stations using proximity information maintained by a proximity server
`
`10
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`associated with an infrastructure network in accordance with at least one embodiment of the
`
`present invention.
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`Figures 8, 9 and I OA-1 OD are block diagrams illustrating various tables of proximity
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`information that may be maintained by a proximity server in accordance with at least one
`
`embodiment of the present invention.
`
`15
`
`Figures 11, 12A-12C and are schematic and flow diagrams illustrating an exemplary
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`technique for identifying wireless stations within a transmission/reception range of another
`
`wireless station in accordance with at least one embodiment of the present invention.
`
`Figure 14 is a schematic diagram illustrating a technique for obtaining one or more user
`
`identifications (IDs) associated with a proximate wireless station in accordance with at least one
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`20
`
`embodiment of the present invention.
`
`Figure 15 is a schematic diagram illustrating an exemplary table of information related to
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`associates of a user of a wireless station in accordance with at least one embodiment of the
`
`present invention.
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`Figure 16 is a flow diagram illustrating an exemplary technique for notifying a wireless
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`25
`
`station user of one or more proximate wireless station users using the table of Figure 15 in
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`accordance with at least one embodiment of the present invention.
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`Figure 17 is a flow diagram illustrating exemplary techniques for communicating with a
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`proximate wireless station in accordance with at least one embodiment of the present invention.
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`-3-
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`

`

`PATENT
`Attorney Docket No. 56162.000497
`GV297
`
`Figure 18 is a schematic diagram illustrating an independent link protocol (IDLP)
`
`technique for establishing a wireless direct link between proximate wireless stations in
`
`accordance with at least one embodiment of the present invention.
`
`Figure 19 is a schematic diagram illustrating an exemplary IDLP frame used by the
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`5
`
`technique of Figure 18 in accordance with at least one embodiment of the present invention.
`
`DETAILED DESCRIPTION OF THE INVENTION
`
`The following description is intended to convey a thorough understanding of the present
`
`invention by providing a number of specific embodiments and details involving the identification
`
`of, and communication with, proximate wireless stations. It is understood, however, that the
`
`10
`
`present invention is not limited to these specific embodiments and details, which are exemplary
`
`only. It is further understood that one possessing ordinary skill in the art, in light of known
`
`systems and methods, would appreciate the use of the invention for its intended purposes and
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`benefits in any number of alternative embodiments, depending upon specific design and other
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`needs.
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`15
`
`For ease of illustration, the various techniques of the present invention are discussed
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`below in the context of IEEE 802.11-based wireless networking. However, those skilled in the
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`art, using the teachings provided herein, may advantageously implement the disclosed techniques
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`in other wireless networks. Accordingly, reference to techniques and components specific to
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`IEEE 802.11, such as a media access control (MAC) addresses, applies also to the equivalent
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`20
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`technique or component in other wireless network standards unless otherwise noted.
`
`Referring now to Figure 1, an exemplary implementation of one or more techniques is
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`illustrated in accordance with at least one embodiment of the present invention. Figure 1 depicts
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`a top view 100 of a building, where the building may include any of a variety of structures, such
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`as, for example, an airport, a shopping mall, a factory, a business office, a school campus, a
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`25
`
`residence, and the like. Situated at various points within the buildings interior are a plurality of
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`access points 102-118 (illustrated as AP 1-AP 9, respectively) having coverage areas 122-138,
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`respectively. The access points 102-118 typically are connected via a backbone network (not
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`illustrated) to form one or more extended service sets (ESSs). The backbone network in turn
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`- 4 -
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`

`

`PATENT
`Attorney Docket No. 56162.000497
`GV297
`
`typically is connected to an infrastructure network, such as, for example, a wide area network
`
`(WAN), metropolitan area network (MAN), the Internet, etc. Thus, wireless network access to
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`the infrastructure network may be provided to one or more wireless stations 140-172 (illustrated
`
`as S 1-S 17, respectively) that are positioned within one or more of the coverage areas 122-138.
`
`5
`
`The wireless stations 140-172 include devices enabled to communicate wirelessly using
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`one or more protocols supported by one or more the access points 102-118. Such protocols may
`
`include, for example, the IEEE 802.11 protocols (802.1 la/b/e/g/i, etc. Examples ofwireless(cid:173)
`
`enabled devices may include notebook ( or "laptop") computers, handheld computers, desktop
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`computers, workstations, servers, portable digital assistants (PDAs), cellular phones, etc.
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`10
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`In conventional wireless applications, a wireless station typically is unaware of the
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`position or proximity of wireless stations and is further unaware of the one or more user IDs
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`associated with the users of nearby wireless stations. In many instances, however, a user of a
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`wireless station may desire to receive notification of other users of proximate wireless stations.
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`Particularly, a certain user may want to be notified of other users with whom the certain user has
`
`15
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`some sort of association (i.e., "associates" of the certain user). Accordingly, in one embodiment
`
`of the present invention, one or more of the wireless stations 140-172 may be adapted to identify
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`proximate wireless devices and determine one or more user IDs associated with the user or users
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`of the proximate wireless devices. A user's ID may include, for example, a login ID supplied by
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`the user to enable the user's use of the wireless station, an email address associated with the user
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`20
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`and used by an email client operating on the wireless station, a user ID associated with one or
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`more software programs operating on the wireless station, such as an instant messenger client,
`
`and the like.
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`After determining the user ID(s) associated with a nearby station, the wireless station
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`may automatically notify the user of the wireless station. Alternatively, in one embodiment, a
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`25
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`filtering process may be performed to determine whether the user should be notified of a
`
`proximate station user. The filtering process may include, for example, comparing the user ID
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`with a list of associate user IDs or applying one or more notification filter rules that govern the
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`notification process. Examples of notification filter rules may include rules that prevent or allow
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`-5-
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`

`

`•.
`
`PATENT
`Attorney Docket No. 56162.000497
`GV297
`
`notification of proximate users during certain time periods, at certain locations, or in other
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`situations. Exemplary filtering processes are discussed in greater detail herein.
`
`The user of the wireless station may be notified of proximate users in a variety of
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`manners. For example, a pop-up window could be displayed on a display screen of the station
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`5
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`that informs the user of the proximity of the identified proximate user and also may provide
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`additional related information, such as, for example, a value representing the degree of proximity
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`(e.g., a physical distance value). The pop-up window could be displayed in conjunction with a
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`communications program operating on the wireless station, such as an email client or an instant
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`messaging program. Notification also may be provided by, for example, automated speech
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`10
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`output by a speaker of the station, transmitting an email to an email client operating on the
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`wireless station, etc.
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`After receiving notification of proximate users or associates, a user may take any of a
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`variety of actions, such as initiating communications with a proximate user via their respective
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`wireless stations, attempting to locate the proximate user for a face-to-face meeting, etc.
`
`15 Communications between nearby wireless stations may be accomplished via conventional
`
`wireless techniques where data communications between two wireless stations are
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`communicated via one or more access points and/or the backbone network. Alternatively, in one
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`embodiment, if the nearby wireless stations are within each other's transmission range, a
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`wireless direct link may be established between the nearby wireless stations whereby data is
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`20
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`communicated directly between the wireless stations without assistance or interference from an
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`access point.
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`After establishing a direct link with the proximate station, various types of information
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`may be transmitted over the direct link. For example, the proximate users could establish an
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`instant messaging session using the direct link, transmit email directly without routing the emails
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`25
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`through the infrastructure network, conduct a videoconference over the direct link, and the like.
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`As another example, if one station belongs to a business and the other station to a potential
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`customer, the direct link formed between the stations could be used to send advertisements,
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`promotionals, coupons, and the like, from the business to the potential customer. Thus,
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`-6-
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`

`

`PATENT
`Attorney Docket No. 56162.000497
`GV297
`
`advertising could be targeted by the business to potential customers that are within a certain
`
`proximity of the business.
`
`As described above, a user of a wireless station may be interested in learning of other
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`users of wireless stations within a certain proximity. The proximity may be defined by the user,
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`5
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`an access point, or a third party based at least in part on equipment capabilities and the desires of
`
`the user and/or administrator of the wireless network. Various exemplary definitions of
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`proximity are described in the following using Figure 1 for illustrative purposes. For ease of
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`reference, the one or more conditions that define a proximity in a particular instance are
`
`collectively referred to herein as a proximity definition.
`
`10
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`In at least one embodiment, wireless stations associated with a same access point (i.e., in
`
`a same basic service set or BSS) may be classified as proximate to each other. For example, the
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`user of wireless station 144 may want be notified only of those wireless stations that are in the
`
`same coverage area 128 of access point 108 to which wireless station 144 is associated. In this
`
`case, wireless stations 146 and 148 may be considered as proximate to wireless station 144. In
`
`15
`
`another embodiment, a user of certain wireless station may consider only those wireless stations
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`that are associated with the same access point or another access point having a coverage area that
`
`overlaps or is immediately adjacent to the coverage area of the access point associated with the
`
`certain wireless station. For example, under this classification of proximity, wireless stations
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`156, 158 and 170 may be considered proximate to wireless station 160 because the access points
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`20
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`114, 118 associated with one or more of the wireless stations 156, 158 and 170 have coverage
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`areas 134 and 138, respectively, which overlap or are immediately adjacent to coverage area 136
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`of access point 116. Further, in one embodiment, wireless stations may be considered proximate
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`when they are associated with the same ESS. To illustrate, assume that access points 102-108
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`form an ESS that spans rooms A and B. In this case, wireless stations 140-150 and 172 may be
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`25
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`considered proximate to each other as each is associated with an access point that is a member of
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`the same ESS.
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`As described above, a proximity definition may be based at least in part on the physical
`
`proximity or logical proximity of the access points to which the wireless stations are associated.
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`-7-
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`

`

`PATENT
`Attorney Docket No. 56162.000497
`GV297
`
`In other circumstances, however, a proximity definition may be substantially based on the
`
`physical proximity, or physical distance, between wireless stations. In one embodiment,
`
`proximity may be defined as a physical distance from a certain wireless station. For example,
`
`the user of the wireless station 152 may consider only those wireless stations within an area 180
`
`5
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`described by a radius 182 as proximate wireless stations. Under this exemplary proximity
`
`definition, wireless stations 150, 154 and 166 would be proximate wireless stations while
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`wireless station 156 would not even though it is associated with the same access point 112 as the
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`wireless station 152. The dimensions of the proximate area may be defined in part by features of
`
`the area where the wireless station is located ( e.g., the walls or ceiling), by the
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`10
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`transmission/reception range of the wireless station (e.g., radius 182 may represent the maximum
`
`transmission range), or by the coverage areas of nearby access points.
`
`Rather than, or in addition to, basing proximity on a distance from the wireless station,
`
`features of the room or building where the wireless station is located may be used to aid in
`
`defining proximity. For example, the contours of room A may set the boundary for an area
`
`15
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`considered proximate by a user of a wireless station located in room A. In another example, the
`
`wireless stations located in either room A or room B may be considered proximate to each other
`
`because rooms A and B are adjacent and wireless stations in either room B or room C may be
`
`considered proximate to each other because Rooms B and C are adjacent. Wireless stations in
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`room A, however, may not be considered proximate to wireless stations in room C, and vice
`
`20
`
`versa, in this example because the areas of room A and C are not adjacent.
`
`In other embodiments, proximity may be defined based on both physical proximity of the
`
`wireless stations and the proximity of access points. For example, wireless stations may be
`
`considered to be proximate when they are located in the same room and are associated with the
`
`same ESS or are associated with access points having overlapping or adjacent coverage areas.
`
`25 Although various exemplary proximity definitions have been disclosed, other definitions of
`
`proximity may be utilized based on the teachings provided herein without departing from the
`
`spirit or the scope of the present invention.
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`-8-
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`

`

`PATENT
`Attorney Docket No. 56162.000497
`GV297
`
`Referring now to Figures 2 and 3, an exemplary wireless station 202 for implementing
`
`the various techniques described herein and an exemplary method 300 for its use are illustrated
`
`in accordance with at least one embodiment of the present invention. The wireless station 202
`
`includes a radio frequency (RF) transceiver 204, one or more processors 206, a proximity
`
`5
`
`identification module 208, a notification module 210 and a link module 212. The wireless
`
`station 202 further may include one or more software applications 214, 216. The software
`
`applications 214,216 may include, for example, communications based applications such as an
`
`email client, an instant messaging client, videoconferencing software, and the like. The wireless
`
`station 202 further may include a global positioning system (GPS) receiver 218 for determining
`
`10
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`the position of the wireless station 202.
`
`In at least one embodiment, data and other signaling is communicated between the
`
`wireless device 202 and one or more access points 220 or other wireless stations 222, 224 as
`
`frames represented by RF energy transmitted by and received via the RF transceiver 204.
`
`Incoming data from the RF transceiver 204 may be processed by the processor 206 using one or
`15 more protocol stacks 226, such as, for example, an Internet Protocol (IP) stack. The resulting
`
`extracted data may be used by the proximity identification module 208, the notification module
`
`210, the link module 212 and/or one or more of the software applications 214, 216 as described
`
`herein. Similarly, data generated by one or more of the modules 208-212 and/or software
`
`applications 214, 216 may be encapsulated or otherwise processed by the processor 206 using
`
`20
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`the one or more protocol stacks 226 and transmitted to the access point 220 or wireless stations
`
`222, 224 via the transceiver 204.
`
`In at least one embodiment, the modules 208-210 are at least partially implemented as
`
`software executed by one or more processors 206 to perform the associated function. In other
`
`embodiments, some or all of the modules 208-210 may be implemented as hardware, firmware,
`
`25
`
`or a combination thereof For example, the modules 208-212 may be implemented as a software
`
`application installed on and executed by the wireless station 202 to perform the proximity
`
`detection, notification, and link establishment techniques described herein. Alternatively, the
`
`modules 208-212 may be implemented as software "plug-ins" for implementation in conjunction
`
`with another software application, such as an email client application.
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`-9-
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`

`

`PATENT
`Attorney Docket No. 56162.000497
`GV297
`
`Referring to Figure 3, an exemplary method 300 illustrating an operation of the wireless
`
`station 202 is illustrated. The method 300 initiates at step 302 wherein the proximity
`
`identification module 208 identifies wireless stations proximate the wireless station 202 under
`
`one or more proximity definitions. In one embodiment, the proximity identification module 208
`
`5
`
`identifies proximate wireless stations using a direct polling approach as described with reference
`
`to Figure 4. In another embodiment, the proximity identification module 208 identifies
`
`proximate wireless stations based at least in part on proximity information provided by the
`
`access point 220 or a proximity server implemented by, or connected to, the access point 220 as
`
`described with reference to Figures 6-1 OD. Alternatively, the proximity identification module
`
`10
`
`208 may identify proximate wireless stations using an automatic peer discovery technique as
`
`described with reference to Figures 12-14B. Other techniques for identifying proximate wireless
`
`stations may be implemented without departing from the spirit or the scope of the present
`
`invention.
`
`At step 304, the proximity identification module 208 determines one or more user IDs
`
`15
`
`associated with the identified proximate wireless stations. A user ID may include, for example, a
`
`login ID used to access the wireless station, an email address associated with a user of the
`
`wireless station, a user ID provided by the user in response to a request for identification, a user
`
`ID provided specifically for proximate identification purposes, etc.
`
`In one embodiment, the user
`
`ID of the user of a proximate wireless station may be received by the proximity identification
`
`20 module 208 as data transmitted by the proximate wireless station in response to a identification
`
`request transmitted by the proximity identification module 208. Alternatively, the user ID of a
`
`user of a proximate wireless station may be provided by the proximity server or the access point
`
`220.
`
`As noted above, in some instances the user of the wireless station 202 may want to be
`
`25
`
`notified of a proximate station user only under certain conditions. For example, one condition
`
`may be that the proximate station user be associated in some way with the user of the wireless
`
`station 202, i.e., the proximate station user is an associate of the user of the wireless station 202.
`
`An associate may include, for example, a family member, a friend, a co-worker, a business
`
`associate, a fellow club member, etc. Accordingly, at step 306, the user IDs of proximate
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`-10-
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`

`

`PATENT
`Attorney Docket No. 56162.000497
`GV297
`
`wireless stations may be compared to a list of user IDs related to identified associates of the user
`
`of the wireless station 202. In the event that the user ID of a proximate wireless station
`
`substantially matches a user ID on the list of associate IDs, the proximity identification module
`
`208 may identify the user of the proximate wireless station as an associate. In other
`
`5
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`embodiments, however, the user of the wireless device 202 may opt to receive notification of
`
`proximate users regardless of an association, or lack thereof, with the user of the wireless device
`
`202. In this case, step 306 may be omitted.
`
`At step 308, the notification module 210 notifies the user of the wireless station 202 of
`
`the proximity of nearby station users. The notification module 210 may notify the user by, for
`
`10
`
`example, displaying a display window having proximate user information on a display screen of
`
`the wireless station 202 for observation by the user, by playing an automated voice output
`
`identifying proximate users, by sending an email to an email client operating on the wireless
`
`station 202, etc.
`
`In certain instances, however the notification module 210 performs a filtering process
`
`15
`
`before notifying the user of proximate users. The filtering process may include subjecting the
`
`user IDs associated with the proximate wireless stations to one or more notification filter rules
`
`set by the user of wireless station 202. The one or more notification filter rules may include, for
`
`example, conditions relating to the time of notification, the place of notification, the means of
`
`notification, and the like. For example, the wireless station 202 may include a notebook
`
`20
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`computer and the user of the wireless station may work at an office with other workers having
`
`similarly configured notebook computers. The user therefore may not desire to receive
`
`notification of the proximity of associates at the office due to user's preexisting awareness that
`
`the other workers are proximate due to their co-employment at the same office. Accordingly, the
`
`user may set a notification filter rule whereby no notification is given for proximate users
`
`25
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`identified as coworkers when the wireless station 202 is within the confines of the user's office.
`
`After notifying the user of proximate users, the user may be provided with the choice of
`whether to initiate a direct link with one or more proximate wireless stations. If the user does not
`
`want to establish a direct link, the user may so indicate at step 310 and the method 300
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`-11-
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`

`PATENT
`Attorney Docket No. 56162.000497
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`
`terminates at end step 312. Otherwise, the user may select one or more proximate users with
`
`whom the link module 212 may attempt to establish a direct link.
`
`At step 314, the link module 212 may initiate the one or more direct link techniques to
`
`establish a direct link with the wireless station(s) of the selected proximate user(s). Any of a
`
`5
`
`variety of techniques may be used to establish a direct link, two of which are discussed with
`
`reference to Figures 17-19. After a direct link is established at step 316, the user may
`
`communicate with the proximate user, and vice versa, via the direct link at step 318. Such
`
`communications may include instant messaging, direct email, video conferencing, etc.
`
`Referring now to Figure 4, an exemplary direct polling technique 400 for identifying
`
`10
`
`proximate wireless stations is illustrated in accordance with at least one embodiment of the
`
`present invention. In the illustrated example, the proximity identification module 208 of station
`
`202 generates and provides for transmission a poll frame 402 having a broadcast or multicast
`
`MAC address in its destination address field. The poll frame 402 further may include, for
`
`example, data identifying the frame as a request for wireless devices to identify themselves upon
`
`15
`
`receipt of the poll frame 402. In this case, the proximate wireless stations 222, 224 may prepare
`
`and transmit poll response frames 404 and 406, respectively, for receipt by the wireless station
`
`202. The poll response frames 404 and 406 may include, for example, data representing the
`
`MAC address of the proximate wireless station sending the poll response frame, an indicator of
`
`the type of wireless station (e.g., PDA, notebook computer, cell phone, etc.), one or more user
`
`20
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`IDs associated with the wireless station, and the like.
`
`It will be appreciated that the receipt of a poll response frame from a wireless station
`
`indicates a strong possibility that the wireless station is nearby. Based on this possibility, upon
`
`receipt of a broadcast response frame, the proximity identification module 208 may insert
`
`relevant data from the poll response frame into a response table 408 maintained at the wireless
`
`25
`
`station 202. In other embodiments, rather than transmitting a poll response frame in response to
`
`a poll frame 402, the wireless stations 202, 222, and 224 may be adapted to periodically transmit
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`a beacon frame, similar to the poll response frames 404 and 406, identifying the MAC address,
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`type, user ID, etc., of the wireless station transmitting the beacon frame. Upon receipt of a
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`PATENT
`Attorney Docket No. 56162.000497
`GV297
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`beacon frame from another wireless station, the receiving wireless station may add information
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`from the beacon frame to the response table 208.
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`In the illustrated example, the response table 408 includes an entry for each broadcast
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`response frame received, the entry including the MAC address (column 410), type (column 412)
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`and user ID (column 414) associated with the wireless station transmitting the response frame.
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`Information from the response table 408 therefore may be used by the proximity identification
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`module 408 and notification module 410 to identify proximate station users and to provide
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`notification of their proximity.
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`Referring now to Figure 5, an exemplary technique for identifying proximate wireless
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`stations based on proximity information provided an access point is illustrated in accordance
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`with at least one embodiment of the present invention. IEEE 802.11 and other wireless standards
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`describe an association process whereby a wireless station that enters the coverage area of an
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`access point may identify itself to the access point and request that the access point handle
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`incoming and outgoing frames on behalf of the wireless station. In at least one embodiment, the
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`access point and wireless device may be adapted to provide proximity information during or in
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`response to the association process.
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`To illustrate, the access point 502 may be adapted to maintain an association table 504
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`that stores information relating to wireless stations associated with the access point 502. This
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`information may include, for example, the MAC address of the wireless station, the type of
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`20 wireless station, user ID(s) associated with the wireless station, etc.
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`When wireless device 506 enters the coverage area of the access point 502 (already
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`associated with wireless stations 508 and 510), the wireless station 506 may transmit an
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`association request frame 512 to the access point 502 requesting association with the access point
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`502. Information related to the wireless device 506 may be transmitted as part of the association
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`request 512 or in subsequent frame(s). Upon receipt of the frame(s) containing information
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`related to wireless station 506, the access point 502 may use this in