KR101490143B1 - Apparatus and method for enabling discovery of wireless devices - Google Patents

Abstract

Disclosed are a method and apparatus for discovering concealed wireless devices in a wireless network employing a directional antenna system and preventing the partitioning of the wireless network. The first wireless device located in the first antenna sector is connected in response to the initial first beacon. The first beacons are received from the connected first wireless device during corresponding first beacon periods. During connection with the first wireless device, at least a second antenna sector is scanned during at least one first beacon period to listen to second beacons from a second wireless device in a second antenna sector. While the second antenna sector is being scanned, the first beacons are not received. The second wireless device is connected in response to the initial second beacon. Second beacons are then received from the connected second wireless device during corresponding second beacon periods, and the first beacons are received during corresponding first beacon periods.

Description

[0001] APPARATUS AND METHOD FOR ENABLING DISCRETE OF WIRELESS DEVICES [0002]

The present invention relates to an apparatus and method for enabling discovery of wireless devices.

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This application is related to US provisional patent application entitled " Apparatus and Method Enabling the Discovery of Wireless Devices "by Richard Chen and Chun-Ting Chouwu, entitled PCIP.558, the subject of which is incorporated herein by reference .

Evolution continues in wireless communication technology. For example, Wireless Local Area Networks (WLAN) and Wireless Personal Area Networks (WPAN) networks are becoming more common in homes and businesses. Such networks may include many independent wireless electronic devices or terminals that communicate wirelessly with one another. WLANs and WPANs can operate in accordance with a number of different available standards, including IEEE standards 802.11 (Wi-Fi), 802.15 (Bluetooth) and 802.16 (WiMax) and WiMedia Alliance Ultra- have.

FIG. 1 is a block diagram illustrating a conventional wireless network 100 that includes multiple terminals configured to communicate with one another via an exemplary WPAN 125. In FIG. Wireless terminals may include any electronic devices or nodes configured to communicate with one another. 1 illustrates a home network in which electronic devices include a personal computer 120, a digital television set 121, a digital camera 122, and a personal digital assistant (PDA) The network 100 may also include an interface to other networks, such as a modem 130, to provide access to all or some of the wireless devices 120 to 123 for the Internet 140, . ≪ / RTI > Of course, there are many different types of wireless networks in which electronic devices communicate with each other, including networks in manufacturing plants, medical facilities, security systems, and the like.

Wireless devices can communicate with each other using directional antennas that extend the transmission range. For example, recent wireless networks operate in very high frequency bands (e.g., 60 GHz) and thus use directional antennas to compensate for high path loss associated with high frequency bands. In both central and distributed wireless networks, wireless devices using directional antennas must align their respective antennas simultaneously to communicate. In other words, the wireless devices must first find each other, which is accomplished by the wireless devices scanning (e.g., sweeping their antenna beams) around the surrounding areas. However, if there is no preconditioning between them to ensure that the wireless devices sweep their antenna beams at the same time, the wireless devices can not find each other.

Beacons are widely used to convey important control information between devices. The beacons are always broadcast so that all devices within the transmission range of the beaconing device can receive the beacons. For example, an IEEE 802.11 access point periodically transmits beacons so that IEEE 802.11 wireless devices around the access point can associate with and communicate with the access point. As described above, in wireless networks where directional antennas are used, beacons can only be transmitted in certain directions. As a result, only a limited number of devices around the non-coring device will receive the beacons, thus making the beacons less useful. Wireless devices may be preprogrammed to recognize the direction of each other's antennas, but this requires a protocol for coordinating beacon transmission, reception, and processing as well as antenna orientation of the wireless devices.

In other words, although the wireless devices are within the same network 100 and in the vicinity of each other, the wireless devices can not find each other and communicate with each other. Such coordination or synchronization is difficult and costly to implement. However, wireless devices that do not have a common time-domain reference point for coordinating antenna control and / or beacon transmissions will not properly communicate as a network.
US 2001/0036843 A1 describes a network system using a multi -qlz antenna to communicate with multiple remote stations.
WO 2005/076543 A1 describes a distributed MAC protocol comprising superframes with slotted non-coring periods. The non-coring period may be fixed or changed. The non-coring protocol specifies initializing the ad-hoc network by means of initiating a non-coring period, concatenating existing non-coring periods of the ad-hoc network, and resolving conflicts during the non-coring period .

Accordingly, there is a need in particular to provide wireless devices and methods of wireless communication that provide a mechanism for wireless devices to find and communicate with each other, particularly when wireless devices use directional antenna systems.

There is provided a method of discovering wireless devices in a wireless network utilizing a directional antenna system according to claim 1 and an apparatus configured to communicate with a plurality of wireless devices via a wireless network according to claim 11. Embodiments of the method and the apparatus are also defined in the dependent claims.
In one aspect of the present invention, a method is disclosed for discovering concealed wireless devices in a wireless network using a directional antenna system, and for preventing division of a wireless network. The method comprising the steps of: the wireless device coupling the first wireless device located in the first antenna sector in response to an initial first beacon received from the first wireless device; Receiving, by the wireless device, a plurality of first beacons from the connected first wireless device during corresponding first beacon periods; And during a first beacon period of at least one of the plurality of first beacon periods to listen to second beacons from a second wireless device in a second antenna sector while the wireless device is connected to the first wireless device, And scanning at least a second antenna sector. The method further includes stopping, for the wireless device, transmitting the first response beacons while scanning at least the second antenna sector. The method includes for the wireless device a step of stopping scanning for additional beacons when connecting a predetermined number of wireless devices. At least while the second antenna sector is being scanned, the first beacons are not received.

The method may further comprise transmitting multiple first response beacons to the connected first wireless device in response to the received first beacons. While at least the second antenna sector is being scanned, the first response beacons are not transmitted.

The method includes receiving an initial second beacon from a second wireless device while scanning the second antenna sector; Connecting a second wireless device in response to an initial second beacon; And receiving multiple second beacons from the connected second wireless device during corresponding second beacon periods. At least some of the first beacons continue to be received.

When the first beacon periods occur at different times than the second beacon periods, the method may further comprise receiving each of the first beacons and the second beacons. When the first beacon periods occur at the same times as the second beacon periods, the method may further comprise alternating receiving the first beacons and the second beacons.

The method may further comprise transmitting a plurality of second response beacons to the connected second wireless device in response to the received second beacons. When transmitting the first response beacons occurs at the same times as the second beacon periods, the method may further comprise alternating transmitting the first response beacons and receiving the first beacons. When transmitting the second response beacons occurs at the same times as the first beacon periods, the method may further comprise alternating transmitting the second response beacons and receiving the first beacons.

The method includes the steps of: during a first beacon period of one of a plurality of first beacon periods and during a second beacon period of one of multiple first beacon periods, while the first wireless device and the second wireless device are connected, And scanning at least the third antenna sector to listen for beacons of < RTI ID = 0.0 > 3. ≪ / RTI > The step of transmitting the response beacons while the third antenna sector can be scanned may be stopped. While the third antenna sector is being scanned, the first beacons and the second beacons can not be received. Scanning the second antenna sector may include sweeping the beam of the directional antenna system.

According to an exemplary embodiment, there is provided an apparatus for communicating with multiple wireless devices over a wireless network, the apparatus being initially connected to a first one of a plurality of antenna sectors arranged in a first antenna sector. The apparatus includes a directional antenna system, a transceiver, and a processor. A directional antenna system is configured to communicate over a wireless network within antenna sectors. The transceiver is configured to receive multiple first beacons from the connected first wireless device via the antenna system during corresponding first beacon periods. The processor is configured to control the antenna system to scan at least a second antenna sector of the antenna sectors during a first beacon period of at least one of the first beacon periods to listen to beacons from wireless devices. The processor is further configured to stop transmitting the first response beacons while scanning at least the second antenna sector. The device is configured to stop scanning for additional beacons when connecting a predetermined number of wireless devices. While the directional antenna system is scanning, the first beacons are not received, and the device remains connected to the first wireless device.

The transceiver may be configured to receive an initial second beacon from a second wireless device disposed in a second antenna sector while the antenna system is scanning, thereby causing the device to associate with the second wireless device. The transceiver may also be configured to receive multiple second beacons from the connected second wireless device during corresponding second beacon periods, while being configured to continue to receive at least some of the first beacons. The antenna system may include one of an antenna array or a steerable antenna.

When the first beacon periods occur at different times than the second beacon periods, the transceiver may be configured to receive each of the first beacons and the second beacons. When the first beacon periods occur at the same times as the second beacon periods, the transceiver may be configured to alternate receiving the first beacons and the second beacons.

The transceiver transmits a plurality of first response beacons to the connected first wireless device in response to the received first beacons and transmits multiple second response beacons to the connected second wireless device in response to the received second beacons. Lt; / RTI > While the antenna system is scanning the antenna sectors, the first response beacons can not be transmitted. When transmitting the first response beacons occurs at the same times as the second beacon periods, the transceiver may alternate transmitting the first response beacons and receiving the second beacons. When transmitting the second response beacons occurs at the same times as the first beacon periods, the transceiver may alternate transmitting the second response beacons and receiving the first beacons.

According to an exemplary embodiment, a method according to the appended claims is provided for a secondary wireless device to discover multiple primary wireless devices over a wireless network, wherein activation schedules of the secondary wireless device and the primary wireless devices It is not synchronized. The method includes receiving first primary beacons from a first primary wireless device in a first antenna sector and responsively transmitting first secondary beacons to a first primary wireless device; Skipping receiving first primary beacons from a first primary wireless device; And skipping receiving first primary beacons, scanning other antenna sectors and listening to additional primary beacons. The method also includes receiving an initial second primary beacon from a second primary wireless device in a second antenna sector while scanning antenna sectors and responding to the initial second secondary beacon in response to a second Transmitting to the primary wireless device; And receiving second primary beacons from the second primary wireless device and in response sending secondary beacons to the second primary wireless device, and in addition, receiving from the first primary wireless device a first Receiving the primary beacons, and responsively transmitting the first secondary beacons to the first primary wireless device.

The first primary beacons may be received during a first time period and the second primary beacons may be received during a second time period. When the first time period conflicts with the second time period, the method further comprises alternating receiving the first primary beacons and the second primary beacons.

The present invention provides wireless devices and methods of wireless communication that provide a mechanism for wireless devices to find and communicate with each other.

1 is a block diagram of a conventional wireless communication network;
2 is a block diagram of exemplary primary devices communicating with a second device in a wireless network in accordance with various embodiments.
3 is a functional block diagram of an exemplary wireless device in accordance with various embodiments.
Figures 4A-4C are block diagrams of beacon periods of wireless devices according to an embodiment.
5 is a flow diagram of a wireless device discovery process in accordance with various embodiments.

In the following non-limiting detailed description, illustrative embodiments which disclose specific details are set forth in order to provide a thorough understanding of embodiments in accordance with the teachings of the present invention. It will be apparent, however, to one skilled in the art, that other embodiments in accordance with the teachings of the invention, as defined by the appended claims, are intended to fall within the scope of the appended claims, which depart from the specific details disclosed herein. Further, descriptions of known devices and methods may be omitted so as not to obscure the description of the exemplary embodiments. Such methods and apparatus are expressly within the scope of the inventive concepts as defined by the appended claims.

In various embodiments, the protocol controls beacons transmitted and received via the directional antennas of wireless devices in a wireless network, such as WLAN or WPAN. The protocol provides the wireless devices with the ability to transmit beacons in a coordinated manner in a WLAN or WPAN using directional antennas. Thus, wireless devices may exchange information, either directly or indirectly, via beacons to enable network management, data transmission, and other communications, without prior coordination of antenna direction or time synchronization of wireless devices.

2 is a block diagram of an exemplary wireless network 200 that may be a WLAN, WPAN, etc., in accordance with various standards and protocols. Each exemplary wireless device 210, 220, 230 of the wireless network 200 transmits and receives beacons via the directional antennas. For example, each of the wireless devices 210, 220, and 230 may use a switching beam antenna or a steering antenna to cover a wide area by a beam sweep / switch. However, the lack of coordination during beam sweeping among the wireless devices 210, 220, 230 may cause hidden-node problems, or otherwise substantially divide the network to be connected.

In FIG. 2, the wireless devices 210 and 230 are labeled as primary devices, and the wireless device 220 is labeled as a secondary wireless device. For the sake of discussion, the difference between the primary and secondary devices is that the primary devices (e.g., wireless devices 210, 230) are located in shaded areas (A, B, C, D) Lt; RTI ID = 0.0 > 200 < / RTI > The secondary devices (e.g., wireless device 220) receive the primary device beacons and respond to the primary device beacons. The exemplary primary devices 210 and 230 may be, for example, network access points and the exemplary secondary device 220 may be a wireless network such as a personal computer, a digital television set, a digital camera, a PDA, Lt; RTI ID = 0.0 > 200, < / RTI >

The location and orientation of the wireless devices 210, 220, 230 are not known a priori. Thus, at operation (or upon entering network 200), wireless device 210 may determine the location of, for example, other devices (e.g., wireless device 220) Lt; RTI ID = 0.0 > antennas < / RTI > for establishing communications. When the primary device 210 has not received any beacons after scanning for a period of time (e.g., one superframe), the primary device may transmit beacons to each of its beams or to each of the antenna sectors Try to discover other wireless devices. Figure 2 shows wireless device 210 and wireless devices 220, 230 having four antenna sectors for discussion. It is understood that each of these devices may have any number of antenna sectors without departing from the spirit and scope of the various embodiments as defined by the appended claims. Also, the wireless devices 210, 220, 230 do not need to know the number or locations of antenna sectors of other devices.

The wireless device 210 transmits beacons to all of its four beams indicated by shaded sector areas A-D. The wireless device 220 will subsequently operate (or otherwise enter the network 200) and begin scanning its corresponding antenna sectors A-D. The wireless device 220 receives the primary beacon transmitted by the wireless device 210 in the antenna sector A at its antenna sector C because the wireless device 210 actively transmits the beacons. The wireless device 220 responds by sending a secondary beacon to the wireless device 210 in the opposite direction, and thus is associated with the wireless device 210.

When wireless device 230 is operating (or otherwise enters network 200), wireless device 230 also begins scanning its corresponding sectors A-D. The wireless device 230 may not be able to receive (listen to) primary beacons transmitted from the wireless device 210 due to, for example, path loss, low signal strength, signal interference, interrupts, Thus, the wireless device 230 will begin transmitting its own primary beacons in all four sectors of its antenna sectors A-D. However, in a conventional system, the wireless device 220 proximate to the wireless device 230 will not be able to listen to the primary beacons transmitted from the wireless device 230, (E.g., in sector C of wireless device 220). As a result, because the wireless device 230 can not communicate with the wireless devices 210 and / or 220, the network 200 is partitioned.

In order to avoid partitioning the network 200, the wireless device 220 may be configured to use the embodiments of the present invention to allow the wireless device 230 to connect to the wireless devices 210, 220 after they establish a communication session Lt; / RTI > More specifically, the wireless device 220 skips its secondary beacon transmission to the wireless device 210 to listen to and receive beacons from the new primary device (s) (e.g., wireless device 230) do. The wireless device 220 sends the response secondary beacons to any new primary devices and, if necessary, transmits the secondary beacons to the different antenna sectors to avoid collisions in reception / transmission of the beacons with the wireless device 210. [ Will shift transmissions.

3 is a functional block diagram of an exemplary secondary wireless device 220 that is configured to communicate with exemplary primary wireless devices 210 and 230 in accordance with various embodiments over the wireless network 200. The secondary wireless devices 220, It is understood that although the wireless device 220 is shown and discussed in detail, it is understood that the wireless devices 210, 230 are configured and function in substantially the same manner as the wireless device 220. [ It is also understood that each of the wireless devices 210, 220, 230 may function as primary or secondary devices depending on which device has transmitted its primary beacons to discover its configuration and / or other wireless devices .

As will be appreciated by those skilled in the art, one or more of the many "parts" shown in FIG. 3 may be physically implemented using a software-controlled microprocessor, logic circuits embedded in hardware, or a combination thereof. Also, although the parts in Fig. 3 are functionally separated for illustrative purposes, they may be variously combined into any physical implementation.

The wireless device 220 includes a transceiver 224, a processor 226, a memory 228, and an antenna system 222. The transceiver 224 includes a receiver 223 and a transmitter 225 and is capable of communicating with other wireless devices such as wireless devices 210 and 230 via the wireless communication network 200 in accordance with appropriate standard protocols To the wireless device (220).

The processor 226 is configured to execute one or more software algorithms, including the discovery algorithms of the embodiments described herein, with the memory 228 providing the functionality of the wireless device 220. [ The discovery algorithm may be, for example, software control of the antenna system 222 implemented in the medium access control (MAC) layer. The processor 226 may include its own memory (e.g., non-volatile memory) for storing executable software code that allows it to perform various functions of the wireless device 220 discussed herein . Executable code may also be stored in designated memory locations in memory 228. [

In Figure 3, the antenna system 222 includes a directional antenna system that provides the ability for the primary device 220 to select multiple antenna beams to communicate with multiple devices in multiple directions. For example, the antenna system 222 may include multiple antennas, each antenna corresponding to one antenna beam, or the antenna system 222 may include multiple different antenna elements < RTI ID = 0.0 > Or a combination thereof.

The antenna system 222 operates various sectors corresponding to the directions in which the antenna system 222 may be directed. For example, the kth wireless device has the ability to transmit and receive signals in _Mk directions or sectors. As described above, these sectors may be created using sectorized antennas, and the sectorized antenna may be selected from among the M _k directional antennas of antenna system 222, As shown in FIG.

As described above, different devices (e.g., primary devices 210, 230 and secondary device 220) may have different numbers of antenna sectors and distributions, Lt; RTI ID = 0.0 > sectors. ≪ / RTI > For example, FIG. 2 illustrates an example in which the antenna system 222 of the wireless device 220 defines four antenna sectors, sectors A, B, C, and D. In FIG. Representative sectors A-D are evenly distributed in four quadrants surrounding wireless device 220 (and wireless devices 210, 230) and are shown in two dimensions to simplify the description. Actual sectors can overlap different or three-dimensional coverage. In addition, in the illustrated exemplary configuration, the wireless device 210 and / or 230 may include a fixed directional antenna directed to one sector in which the wireless device 220 is located.

4A, 4B, and 4C are block diagrams of operational time lines 410, 420, and 430, respectively, corresponding to signals transmitted and / or received by the wireless devices 210, 220, and 230. FIG. Each time line represents one beacon period of a corresponding superframe (not shown) according to various embodiments.

Each of the time lines 410-430 includes a series of consecutive blocks or timeslots within the beacon period that represent fixed time periods associated with the non-coring process. For example, time line 410 shows a beacon period with four slots, slots A-D, corresponding to antenna sectors A-D of wireless device 210. [ Shaded beacon slots represent primary beacon slots in which primary beacons are actively transmitted. Beacon slots A-D indicated by dashed lines represent secondary / response beacon slots for corresponding sectors as specified in the corresponding primary beacon slots of wireless device 210. The arrangement of the primary and secondary beacon slots may be varied, for example, as described in the above-mentioned U.S. Provisional Application, entitled " Device and Method Enabling Discovery of Wireless Devices " , The subject matter of which is incorporated herein by reference. However, the embodiments are not limited to this disclosure. Similarly, time line 430 shows beacon periods with primary and secondary beacons slots A-D corresponding to antenna sectors A-D of wireless device 230. [ The time line 420 shows the individual beacon slots in which the wireless device 220 transmits the response beacons to each of the wireless devices 210, 230.

Timeslots can vary in size without departing from the spirit and scope of the embodiments as defined by the appended claims. For example, the number of slots per superframe and / or the length of time of each time slot may be configured to provide unique advantages for any particular situation and satisfy various design requirements. In addition, the antenna direction and beacon periods are not pre-adjusted or otherwise synchronized among the wireless devices 210,220, 230.

The downward dashed arrows indicate the primary beacons sent to the secondary wireless device 220 by the primary wireless devices 210, 230. The dashed arrows pointing up indicate the response secondary beacons sent by the secondary wireless device 220 to the primary wireless devices 210, 230. As discussed with respect to FIG. 2, the wireless device 210 may only communicate with the wireless device 220 at the antenna sector A due to the relative locations of the wireless devices. Thus, the dashed arrows show the wireless device 210 transmitting primary beacons and receiving secondary beacons only in sector A of the time line 410. Similarly, the wireless device 230 may only communicate with the wireless device 220 at the antenna sector C due to the relative locations of the wireless devices. Thus, the dashed arrows show the wireless device 230 transmitting primary beacons and receiving secondary beacons only in sector C of the time line 430. [

Because the wireless devices 210, 220, 230 are not synchronized, the time periods for exchanging beacons may not overlap or overlap. For example, FIG. 4A shows that primary beacons transmitted by wireless device 210 (time line 410) and wireless device 230 (time line 430) do not interfere with each other, Lt; / RTI > shows the scenario in which the timing is calculated so as not to interfere with each of the secondary beacons transmitted by the secondary (beacon 420). In other words, the time that wireless device 210 transmits and / or receives primary and secondary beacons at its antenna sector A is determined by the time at which wireless device 230 receives primary and secondary beacons at its antenna sector (C) It does not overlap with the time of transmission / reception. Thus, the wireless device 220 need not adjust its timing.

In contrast, FIG. 4B shows a scenario in which the timing of transmitting primary beacons and receiving secondary beacons are completely overlapping. In other words, the time at which the wireless device 210 transmits and / or receives the primary and secondary beacons at its antenna sector A is determined by the time at which the wireless device 230 receives the primary and secondary beacons at its antenna sector C. It is the same as the transmission / reception time. Similarly, FIG. 4C illustrates a scenario in which the timing of transmitting primary beacons and receiving secondary beacons is partially overlapping. In other words, the time that wireless device 210 receives secondary beacons in its antenna sector A is equal to the time that wireless device 230 transmits primary beacons in its antenna sector C. Thus, as discussed below, in response to the scenarios of FIGS. 4B and 4C, the secondary wireless device 220 may determine that the wireless device 230 has detected and connected to the wireless devices 210, 220, Adjustments must be made between the primary wireless devices to maintain communications over the network 200 and avoid partitioning.

5 is a flow diagram illustrating a process for discovering hidden nodes using directional antennas and coordinating beacon transmission and reception, in accordance with an embodiment. The process steps of FIG. 5 will be discussed with some reference to time lines 410-430 of FIGS. 4A-4C.

In step S510, the wireless device 220 powers on, for example, to enter the network 200. [ It is assumed that the wireless device 210 is already on and transmits primary beacons in the slots A-D (e.g., in Figure 4a) at each of its corresponding antenna sectors A-D. The wireless device 220 hears primary beacons in the corresponding beacon period slots in step S512 and scans both of its sectors A-D. Each beacon transmitted by the primary wireless device 210 may include information such as the number of beacon slot (s) to which the receiving secondary wireless device should transmit the response secondary beacon, the location and / or the number of corresponding sectors . In an embodiment, the exchange of primary and secondary beacons may be accomplished according to the above-mentioned US Provisional Application, which is entitled " Device and Method Enabling Discovery of Wireless Devices " The subject matter is incorporated herein by reference.

When the wireless device 220 does not receive the primary beacon (step S514: No), the wireless device 220 repeats step S512 to continue scanning all antenna sectors. When the wireless device 220 detects a primary beacon (step S514: YES), the wireless device 220 sends a response secondary beacon in step S516. The secondary beacon is transmitted in the antenna sector (e.g., sector C) of the wireless device 220 indicated by wireless device 210. Thus, the wireless device 220 is connected to the wireless device 210, and then the wireless devices 210,220 maintain a communication session between the two devices to continue to exchange beacons in step S518.

At step A520, the wireless device 220 skips receiving the primary beacon from the wireless device 210 and / or transmitting the secondary beacon to the wireless device 210. [ This causes the wireless device 220 to scan all of its antenna sectors in step S522 and listen to other beacons, such as primary beacons from the wireless device 230. [ The timing at which the wireless device 220 skips receiving / transmitting the beacons may be varied. The wireless device may skip receiving / transmitting beacons at regular or periodic intervals, e.g., a set, according to a predetermined schedule, or the wireless device may skip irregularly or arbitrarily receive / transmit beacons have. For example, wireless device 220 may skip receiving all other beacons to scan for other antenna sectors (thus, sending all other response beacons). The wireless device 220 may also be configured to transmit all of the number of beacons (e.g., every second, third, fifteenth, etc.) according to the number of times it is desired for the wireless device 220 to check for other wireless devices. . Beacon) can be skipped. In addition, the timing at which wireless device 220 skips receiving / transmitting beacons may vary depending on the number of primary wireless devices to which it is connected. For example, if the wireless device 220 is already associated with two primary wireless devices, then the wireless device 220 determines whether the beacon is associated with both primary wireless devices to scan its antenna sectors in step S52. Lt; RTI ID = 0.0 > periodically < / RTI > This may allow the wireless device 220 to exchange beacons less often with both primary wireless devices.

At step S524, the wireless device 220 determines whether he receives a new beacon (e.g., a beacon from a wireless device other than the wireless device 210). When the wireless device 220 does not receive a new beacon (S524: NO), the wireless device 220 returns to step S518 to continue exchanging beacons with the wireless device 210, and steps S518, S520, the beacon exchange is skipped periodically or arbitrarily. When the wireless device 220 receives a new beacon (e.g., a primary beacon from the wireless device 230) (step S524: YES), the wireless device 220 transmits a new beacon (S526).

In this regard, the wireless device 220 learns information about communications with the wireless device 230 based on the timing of the new beacon and the information contained in the beacon. Thus, the wireless device 220 recognizes the schedule as it must exchange beacons with the wireless device 230. [ In step S528, the wireless device 220 compares the original schedule of beacon exchanges between the schedule and the wireless device 210, and determines whether schedules conflict. For example, Figures 4b and 4c show scenarios in which beacon reception / transmission schedules collide. 4B illustrates how wireless device 220 receives beacons from both wireless devices 210 and 230 in the same time periods and transmits response beacons to both wireless devices 210 and 230 4C illustrates that the wireless device 220 must transmit a response beacon to the wireless device 210 during the same period of time that it receives a beacon from the wireless device 230. [ These scenarios generate collisions, for example, because the wireless device 220 must simultaneously receive / transmit beacons from different devices and the wireless device 220 must direct its directional antenna in different directions.

Thus, when wireless device 220 determines that there are collisions between beacon exchanges (step S528: YES), wireless device 220 sends a beacon exchange with wireless device 210 and wireless device 230 at step S532 . 4B, the wireless device 220 may be configured to receive a primary beacon from the wireless device 210 to receive (and respond to) the primary beacon from the wireless device 230. For example, in the exemplary scenario illustrated in FIG. The wireless device 220 skips receiving the primary beacon from the wireless device 230 to receive (and respond) the primary beacon from the wireless device 210. [ 4C, the wireless device 220 skips sending a response beacon to the wireless device 210 to receive (and respond to) the primary beacon from the wireless device 230. In the example scenario shown in FIG.

As long as successful beacon exchanges are achieved within a predetermined time frame set for the normally adjustable wireless network 200 (e.g., to avoid timing conflicts and / or periodically to scan antenna sectors) ) Skipping beacon transmission / reception will not affect communication sessions between wireless devices. When there is no conflict (step S528: No), the wireless device 220 exchanges both beacons and beacons with both of the wireless devices 210, 230 without alternating the wireless devices 210, 230 in step S530 do.

As long as the communication session (s) continues (step S540: No), the wireless device 220 returns to step S520 and all associated primary wireless devices (e.g., wireless devices 210, 230) And beacon exchanges on a regular or random basis to add additional wireless devices when new beacons are detected. When the communication session (s) ends (step S540: YES), the process ends. In various embodiments, the wireless device 220 may stop scanning for additional beacons based on other criteria. For example, the wireless device 220 can be programmed to stop sector scanning if it is connected to a predetermined number of wireless devices (e.g., four wireless devices or one within each antenna sector).

In accordance with exemplary embodiments, neighboring wireless devices, such as exemplary wireless devices 210, 220, and 230, may communicate without exchanging time schedules, for example, exchanging information and / We can discover each other and meet each other. Thus, in spite of the topology, nearby wireless devices will be well connected and the network will not be partitioned. This scheme can be applied, for example, to help devices using directional antennas to locate each other. Examples for illustration are provided herein and are not intended to limit the scope of the claims, or the scope of the following claims.

While preferred embodiments are disclosed herein, many variations that are within the concept and scope of the present invention are possible. After reviewing the specification, drawings and claims, such variations will be apparent to those skilled in the art. Accordingly, the invention is not limited except as by the spirit and scope of the appended claims.

100: wireless network 120: personal computer
121: digital television set 122: digital camera
123: PDA 125: WPAN
130: modem 140: Internet
200: wireless network 210, 220, 230: wireless device
222: antenna system 224: transceiver
223: Receiver 225: Transmitter
226: Processor 228: Memory
410, 420, 430: Time line

Claims (20)

A method for discovering wireless devices (210, 230) in a wireless network (200) using a directional antenna system and preventing partitioning of the wireless network (200), the method comprising:
The wireless device 220 coupling the first wireless device 210 located in the first antenna sector C in response to an initial first beacon received from the first wireless device 210;
Receiving (S518) a plurality of first beacons from the connected first wireless device (210) during a plurality of first beacon periods in which the wireless device (220) corresponds; And
At least one of the plurality of first beacon periods to listen to second beacons from a second wireless device (230) in a second antenna sector (A) during connection with the first wireless device (210) (S522) the wireless device (220) scanning at least a second antenna sector (A) during one beacon period,
The method includes stopping transmitting the first response beacons (S520) while scanning (S522) at least the second antenna sector (A, B, C, D) Further comprising:
The method includes stopping the step of scanning for additional beacons when connecting a predetermined number of wireless devices (210, 230) to the wireless device (220, 230). ) Discovery method. The method according to claim 1,
Further comprising transmitting (S516, S518) a plurality of first response beacons to the connected first wireless device (210) in response to the received first beacons,
The first response beacons are not transmitted while at least scanning (S522) the second antenna sector (A). The method according to claim 1,
Receiving an initial second beacon from the second wireless device (230) while scanning the second antenna sector (A)
Coupling the second wireless device (230) in response to the initial second beacon; and
(S518), during a corresponding plurality of second beacon periods, receiving a plurality of second beacons from the connected second wireless device (230) and continuing to receive at least a portion of the plurality of first beacons (210, 230). ≪ / RTI > The method of claim 3,
When the first beacon periods occur at different times than the second beacon periods,
Further comprising receiving (S530) each of the first beacons and the second beacons (S530). The method of claim 3,
When the first beacon periods occur at the same times as the second beacon periods,
Further comprising alternating (S532) the receiving of the first beacons and the second beacons (S532). The method of claim 3,
Further comprising transmitting (S526) the plurality of second response beacons to the connected second wireless device (230) in response to the received second beacons (S526). The method according to claim 6,
When transmitting the first response beacons occurs at the same times as the second beacon periods,
Further comprising alternating (S532) the sending of the first response beacons and the receiving of the second beacons (S532). The method according to claim 6,
When transmitting the second response beacons occurs at the same times as the first beacon periods,
Further comprising alternating (S532) alternating sending the second response beacons and receiving the first beacons (S532). The method of claim 3,
A first beacon period of one of the plurality of first beacon periods and a second beacon period of one of the plurality of first beacon periods to listen to third beacons while being connected to the first wireless device 210 and the second wireless device 230, Further comprising scanning at least a third antenna sector (A, B, C, D) during a second beacon period of one of the two beacon periods,
Wherein during the scanning of the third antenna sector (A, B, C, D), the step of transmitting the response beacons is stopped. The method of claim 3,
Wherein the scanning of the second antenna sector (A) comprises sweeping the beam of the directional antenna system. A device (220) configured to communicate with a plurality of wireless devices (210, 230) through a wireless network (200), the device (220) comprising a first one of a plurality of antenna sectors (A, B, C, D) The apparatus (220) initially connected to a first wireless device (210) located within an antenna sector (C), the device comprising:
A directional antenna system (222) configured to communicate via the wireless network (200) at the plurality of antenna sectors (A, B, C, D);
A transceiver (224) configured to receive a plurality of first beacons from the connected first wireless device (210) via the antenna system (222) during a corresponding plurality of first beacon periods; And
Wherein the antenna system (222) is configured to receive the plurality of antenna sectors (A, B) during a first beacon period of at least one of the plurality of first beacon periods to listen to beacons from the plurality of wireless devices And a processor (226) configured to control scanning at least a second antenna sector (A) of the plurality of sectors (B, C, D)
The processor 226 is further configured to stop transmitting the first response beacons while scanning at least the second antenna sector A,
The device 220 is configured to stop scanning for additional beacons when connecting a predetermined number of wireless devices 210 and 230 to the plurality of wireless devices 210 and 230 via the wireless network 200. [ (220). 12. The method of claim 11,
While the antenna system 222 is scanning, the transceiver 224 receives an initial second beacon from a second wireless device 230 located in the second antenna sector A, and the device 220 And to be coupled to the second wireless device (230)
The transceiver 224 receives a plurality of second beacons from the connected second wireless device 230 during a corresponding plurality of second beacon periods and continues receiving at least some of the plurality of first beacons. An apparatus (220) configured to communicate with a plurality of wireless devices (210, 230) through a wireless network (200). 13. The method of claim 12,
The antenna system 222 is configured to communicate with a plurality of wireless devices 210, 230 via a wireless network 200, including one of an antenna array or a steerable antenna. 13. The method of claim 12,
The transceiver (224) is configured to receive each of the first and second beacons when the first beacon periods occur at times different than the second beacon periods, via the wireless network (200) An apparatus (220) configured to communicate with a plurality of wireless devices (210, 230) 13. The method of claim 12,
The transceiver (224) is configured to alternate receiving first and second beacons when the first beacon periods occur at the same time as the second beacon periods, via the wireless network (200) An apparatus (220) configured to communicate with a plurality of wireless devices (210, 230). delete delete delete delete delete

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