System and method for reducing side-lobe contamination effects in Wi-Fi access points

A multibeam access point may include a plurality of co-located, beamforming transceivers, each configured to transmit data to a user equipment on a first channel. The multibeam access point may further include a cluster transceiver co-located with the beamforming transceivers, configured to transmit data to the user equipment on a second channel. A processor or controller may monitor whether at least two of the beamforming transceivers have detected data transmission from the user equipment. Based on the monitoring, the processor may allow the cluster transceiver to transmit data to the user equipment.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. Provisional Patent Application No. 61/764,209 filed on Feb. 13, 2013, U.S. Provisional Patent Application No. 61/805,770, filed Mar. 27, 2013, and U.S. Provisional Patent Application No. 61/809,054 filed on Apr. 5, 2013, all of which are incorporated herein by reference in its entirety.

FIELD OF THE PRESENT INVENTION

The present invention relates generally to methods of enhanced performance systems using RF beamforming and/or digital signal processing, in both MIMO and non-MIMO systems.

BACKGROUND

Active antenna systems may implement 1-dimensional and 2-dimensional multi-beam base stations that focus transmission and reception into narrow sub-sectors, facilitate reduced interference to neighboring cells, and enable reuse of the radio spectrum at its own cell by activating independent simultaneous co-channel non-overlapping beams.

Base stations may separate transmission and reception by using different frequencies or different time divisions for transmission and reception. For example, cellular protocols, such as GSM (Global System for Mobile Communications), WiMAX (Worldwide Interoperability for Microwave Access), and LTE (Long-Term Evolution), may sync (synchronize) all transmission and receiving channels using time-division. Wi-Fi base stations, which may incorporate a multi-beamforming cluster of co-located, co-channel Wi-Fi access points, may not inherently include such syncing capabilities and may operate inefficiently when in close proximity, due to the nature of the CSMA/CA (Carrier sense multiple access with collision avoidance) property of the Wi-Fi protocol. The CSMA/CA property may require yielding to all first-come Wi-Fi data transmission in order to avoid transmission collisions or jamming. Further, while co-located, co-channel Wi-Fi access points may provide super-isolation of data transmission via RF manipulation methods, side-lobe interference in adjacent beams may occur in regions nearer to the base stations. Performance may be improved if different radio channels are utilized for data transmission occurring in closer proximity to the base station.

SUMMARY

A multibeam access point may include a plurality of co-located, beamforming transceivers, each configured to transmit data to a user equipment on a first channel. The multibeam access point may further include a cluster transceiver co-located with the beamforming transceivers, configured to transmit data to the user equipment on a second channel. A processor or controller may monitor whether at least two of the beamforming transceivers have detected data transmission from the user equipment. Based on the monitoring, the processor may allow the cluster transceiver to transmit data to the user equipment by, for example, engaging in operations that require the user equipment to register on a different antenna beam and channel than the user equipment originally intended. Further, as the user equipment moves to new locations, the processor may direct the user equipment to a different antenna beam and channel.

DETAILED DESCRIPTION

Embodiments of the invention may be described in reference to the IEEE (Institute of Electrical and Electronics Engineer) 802.11 standard for implementing wireless local area networks (WLAN). The IEEE 802.11 standard may also be known as the Wi-Fi standard. “802.11xx” may refer to any version of the 802.11 standard, such as 802.11a, 802.11g, or 802.11ac, for example. Versions of the 802.11 standard may operate using a technique called Collision Sense Multiple Access/Collision Avoidance (CSMA/CA), a networking method which aims to prevent transmission collisions before they occur. While embodiments of the invention are described in terms of the 802.11 protocol, other network protocols built on the CSMA/CA concept may be used.

Access points (AP's) or transceivers may be grouped together or co-located on a base station to form a multi-beam access point (MBAP). As used herein, transceiver and AP may be used interchangeably as any device having independent transmit and receive functions and capable of acting as a 802.11xx access point. Further as used herein, “beamforming” may refer to the ability to direct data towards a narrow azimuth with high gain or power. Transceivers or access points may be co-located if, under ordinary usage of the CSMA/CA technique, data transmission from one transceiver prevents simultaneous data transmission from another transceiver on the same channel or frequency. The transceivers' co-location or proximity to each other may cause, for example, RF interference, a busy CCA, or an updated NAV. Co-located transceivers may be clustered or grouped together into one base station that serves UE's in a limited geographical area. Co-located transceivers may share processing tasks or may each have separate processing capabilities.

Each AP or transceiver may be coupled to an individual antenna to broadcast or transmit data to a user equipment (UE). A beamforming antenna may be a directive antenna to focus radio energy on a narrow azimuth covering an intended user on a UE. Broadcasting on a narrow azimuth may enable one or the same frequency channel (e.g., the same or overlapping frequency spectrum) to be used simultaneously or concurrently on a different azimuth beam which points to a different UE. A cluster antenna may broadcast on a wider azimuth with lower power than a beamforming antenna.

The IEEE 802.11 standard may determine which frequency channels that AP's may communicate on to minimize interference. For example, the 802.11 standard may require that AP's communicating on non-overlapping frequency channels may only transmit data at 2.4 Ghz in channels 1, 6, or 11 out of a possible 13 channels. For a cluster or group of co-located transceivers or AP's communicating on the same frequency channel, e.g., channel 1, overlapping transmission azimuths in each beam's sidelobes may cause interference between the AP's.

FIGS. 1A and 1Bare illustrations of an antenna pattern originating from a multi-beam access point100, according to embodiments of the invention. MBAP100may include a plurality of co-located beamforming transceivers or access points. (A detailed description of the MBAP100is illustrated inFIG. 3.) Each beam102a-din the antenna pattern may originate or radiate from an individual access point in the MBAP. The access points may share the same communication resources, e.g., they may communicate with a UE on the same frequency channel. While each beam102a-dmay establish an intercept contour directed toward a narrow azimuth which may contain a UE104a, for example, interference may occur in the beams' side lobes in an area106near or close to MBAP100. Each directive beam102a-dmay establish a −82 dBm (power ratio in decibels to one milliwatt) intercept contour with a typical side lobe overlap of 30 dBm. Area106, or the side lobe contamination area (SLC area), may thus represent a −52 dBm contour. Other dBm values may be used. A UE104bin side-lobe contamination area106may be detected on two beams102band102c, and UE104bmay also detect transmission from both beams102band102c.

Access points or transceivers that make up MBAP100may use a CSMA/CA wireless network, including IEEE 802.11 Wi-Fi networks. The 802.11 standard may require each access point to determine whether a radio channel is clear, prior to broadcasting or transmitting data in the channel. The AP may do this by performing a clear channel assessment (CCA), which includes two functions: listening to received energy on an RF interface (termed “energy detection”), or detecting and decoding an incoming Wi-Fi signal preamble from a nearby access point. Due to the CCA function, a UE104bin SLC area106may be communicating with an access point on beam104b, but may prevent an access point from transmitting on beam104cusing the same frequency channel. Further, UE104b's own CCA function may prevent transmission if it detects data transmission from beam104c. In contrast, UE104a, located outside of SLC area106, may not experience these interference issues due to the absence of side-lobe interference.

Embodiments of the invention may provide a system or method of detecting UE's, such as UE104b, within SLC area106and communicating with co-located and co-channel beamforming access points. To avoid the interference problems described above, a controller or processor may allow UE104bto switch to a cluster access point which may communicate on a different frequency than the beamforming access points. Since the CCA function of the 802.11 standard may detect a preamble from other access points even at a low power level, CCA detection may occur at a longer range than the SLC area106. Embodiments of the invention may be configured to switch UE104bto a cluster transceiver or access point at a modified SLC area108to account for all CCA detection areas.

According to some embodiments, shown inFIG. 1B, MBAP100may include a second group or plurality of beamforming access points which transmit to UE's, such as UE104c. The second group of beamforming access points may transmit narrow azimuth beams102e-hin a frequency channel different from beams102a-d. The second group of beams102e-hmay also increase capacity for the MBAP100, but may still have the problem of side-lobe contamination. MBAP100may include a cluster transceiver for transmitting to UE's in SLC area106at a frequency channel different from the frequency channel used in beams102a-dand102e-f.

WhileFIGS. 1A and 1Billustrate SLC area106as having a smooth line contour, the contour area may in practice be more irregular or ragged due to different propagation factors “R” over a transmission path.

FIGS. 2A-2Care graphs that illustrate the relationship between different propagation factors and an SLC area.FIG. 2Ais a graph illustrating a ratio of range varying with different values of R, according to embodiments of the invention. The ratio of range may be the ratio of the distance covered by the main beam and the distance covered by the side lobe. The x-axis202may represent decibels and the y-axis204may represent the ratio of range. The ratio of the range may change with different values of R, a factor which may adjust free space attenuation to attenuation in a more cluttered environment. At 30 dB, side-lobe level may have a reduced range, as values of R increase. For example, at an R of 2.5206, side-lobes that are −30 dB below the main beam may have a range of about 1/16 of the main beam range. As with other examples shown herein, other or different relationships between values may be used, and other or different values may be used.

FIG. 2Bis a graph illustrating signal level varying across a signal path, according to embodiments of the invention. For access points designed with a −82 dBm intercept contour, the maximum coverage of an access point may be 900 feet208. With a side-lobe of −30 dB, the SLC area may have a −52 dBm contour and have a constant R=2.5 over the path. Under these conditions, the side-lobe range may be only about 56 feet210or 1/16 of the 900 foot maximum range.

FIG. 2Cis an illustration of signal level varying across a signal path using real world attenuation. The real world attenuation may vary over distance and use a value for R that ranges from 2.05, nearer to an access point or transceiver, to a value of 2.5 further out several hundred feet. This may be a more realistic estimate since nearer to the AP, obstructions may be less likely while at longer ranges obstructions may increase R. In this graph, the side-lobe processing range extends out to about 125 ft or 13% of the range (125 ft/950 ft). Thus, since R is a key factor in determining SLC area, and R may change along a signal path, the size and shape of the SLC area may be more complex than shown inFIG. 1.

FIG. 3is a schematic diagram of a multibeam access point300, according to embodiments of the invention. Multibeam access point300may include a first plurality of beamforming access points or transceivers302a-dtransmitting on the same channel or frequency channel. MBAP300may further include a second plurality of beamforming transceivers302e-htransmitting on a different frequency channel than transceivers302a-d. Other MBAP's may not include a second plurality of beamforming transceivers. While four transceivers are shown for each group or plurality of transceivers, other numbers of transceivers may be included, but not less than two. Beamforming transceivers302a-hmay be configured to transmit data in a CSMA/CA protocol, such as IEEE 802.11. MBAP300may further include a cluster transceiver303to transmit data to a UE when UE is detected in a SLC area (seeFIG. 1, reference106). Cluster transceiver303may transmit to UE on a different frequency channel than first plurality of transceivers302a-dand second plurality of transceivers302e-h.

Each beamforming transceiver or access point302a-hmay be coupled to a directive antenna304a-h, and each directive antenna304a-hmay form directive beams to transmit data to a UE306. Cluster transceiver303may be coupled to a cluster antenna305which may form a beam covering a wider azimuth and at lower gain than the directive beams originating from directive antennas304a-h. A UE306may be a cell phone, smart phone, tablet or any device with Wi-Fi capability and able to communicate with a Wi-Fi access point, or another wireless capable device. UE's306may be recognized in a WLAN as a Station (STA) device, according to the IEEE 802.11xx protocol. Each transceiver302a-hand303may operate according to the IEEE 802.11xx protocol, or other protocol using CSMA/CA. A MBAP controller308may interface with or control each transceiver302a-hand303. MBAP controller308may include a processor311aand memory311b. The transceivers302a-hand303may each include for example a transmitter309, receiver310, antenna interface or RF circuitry312, and a processor314and memory316, although other or different equipment may be used. Processor314may be a general purpose processor configured to perform embodiments of the invention for example by executing code or software stored in memory316, or may be other processors, e.g. a dedicated processor. In other embodiments, transceivers may share a processor314and memory316to implement software.

Transceivers302a-hand303may each include one or more controller(s) or processor(s)314, respectively, for executing operations and one or more memory unit(s)316, respectively, for storing data and/or instructions (e.g., software) executable by a processor. Processor(s)314may include, for example, a central processing unit (CPU), a digital signal processor (DSP), a microprocessor, a controller, a chip, a microchip, an integrated circuit (IC), or any other suitable multi-purpose or specific processor or controller. Memory unit(s)316may include, for example, a random access memory (RAM), a dynamic RAM (DRAM), a flash memory, a volatile memory, a non-volatile memory, a cache memory, a buffer, a short term memory unit, a long term memory unit, or other suitable memory units or storage units. Processor(s)314may be general purpose processors configured to perform embodiments of the invention by for example executing code or software stored in memory, or may be other processors, e.g. dedicated processors.

According to the IEEE 802.11 protocol, channels 1, 6, and 11 may be examples of non-overlapping channels operating at 2.4 GHz. Other frequencies and frequency channels may be used. The channels may be assigned, for example, so that the first group or plurality of beamforming transceivers302a-dtransmit in channel 1, the second group or plurality of transceivers302e-htransmit in channel 6, and cluster transceiver303transmits in channel 11. Other configurations may be used.

If UE306ais located in a SLC area, for example, MBAP controller308or processor may monitor whether or not two or more beamforming transceivers (e.g., transceivers302aand302b) of the plurality or group302a-dtransmitting on the same frequency have detected UE's presence or activity. UE's presence or activity may be determined or detected by, for example, receiving a registration request. Based on the monitoring, MBAP controller308may allow cluster transceiver303to transmit data to the UE306aby, for example, sending control signals to transceivers302aand302binstructing them to reject registration of UE306a. MBAP controller may monitor other activity between transceivers302a-hand UE to determine whether to allow UE to switch to data transmission with cluster transceiver303. Other kinds of activity or data may be monitored to determine whether at least two beamforming transceivers have detected UE306a. In another embodiment, for example, MBAP controller308may track or store UE's306activity over time. MBAP controller308may track a number of times in a predetermined time period that at least two of the beamforming transceivers have detected data transmission from UE306a. For example, if MBAP controller308determines that at least two beamforming transceivers receive or sense a registration request (or other kinds of activity or data) from UE306aat a threshold number of times in one time period (e.g., 1 second, 200 milliseconds), then MBAP controller308may compel UE306ato register with a different antenna beam and channel by re-registering UE306a.

If a UE306bis not in SLC area, for example, MBAP controller308may determine that two or more beamforming transceivers have not detected UE306band MBAP controller308may not take steps to allow cluster transceiver303to transmit data with UE306b. For example, only one beamforming transceiver, e.g.,304cmay detect UE306b, and MBAP controller308may allow data transmission between UE and the one beamforming transceiver304cto continue or may accept UE's registration with the one beamforming transceiver304c. If MBAP controller308determines that no beamforming transceivers302a-hcan detect a UE306c, then UE306cmay be entirely out of the geographic range of the MBAP300. While the above example was described in reference to the first plurality of beamforming transceivers302a-don a first channel, the above example would also apply to the second plurality of beamforming transceivers302e-htransmitting on a second channel.

MBAP controller308may allow cluster transceiver303to transmit data to UE306aby, for example, rejecting a registration request by UE306ato beamforming transceiver304aor304b. Rejecting registration of UE to allow cluster transceiver to transmit data to UE may be implemented for example in the following manner. Transceivers302a-hmay use the same ESS (Extended Service Set), by using the same Service Set Identification (SSID), e.g., primary SSID “A”. Cluster transceiver303on channel 11 may use a second SSID, e.g., secondary SSID “B”. Thus, beamforming transceivers304a-bmay each maintain a primary SSID “A”, and cluster transceiver303may maintain or store a secondary SSID “B” in memory, e.g., memory316. The UE306amay distinguish each transceiver through a unique Basic Service Set Identification (BSSID) address. UEs306associated with MBAP300may be configured with both SSID “A” and SSID “B” as preferred networks. When UE is located in a SLC area, for example, MBAP controller308may reject UE's306aregistration request to any of beamforming transceivers302a-hwhich have SSID “A”. When UE306ais rejected, UE306amay request registration with cluster transceiver303, which has SSID “B”. MBAP300may be configured so that UE306aobtains exactly the same service and uses the authentication credentials on both the primary and secondary SSID. MBAP300may be capable of fast roaming according to IEEE 802.11r so that UE's306atransitions between primary and secondary SSIDs may occur faster and with less user disruption for UE's306athat are also 802.11r capable.

FIG. 4is a flowchart of a method for rejecting UE requests, according to an embodiment of the invention. In operation402, when a UE attempts to register on a beamforming transceiver, the UE may do so by sending a data frame, shown in a generic format404, according to the specifications of IEEE 802.11, for example. A generic data frame404may be in a standardized data format so that transceivers and UE's understand when to expect certain kinds of information. In a generic data frame404, six bytes may be allocated for a MAC (Media Access Control) address from a sender406of the generic data frame404. Beamforming transceivers (e.g., reference302a-hinFIG. 3) may listen for a generic data frame404from the UE due to the CSMA/MA properties of the 802.11 protocol. In operation408, a MBAP controller (e.g.,308inFIG. 3) may determine if UE is detected by two or more beamforming transceivers by determining if two or more beamforming transceivers receive or sense a registration request from the UE in a SLC area. The MBAP controller may log or track whether a beamforming transceiver receives a generic data frame with a sender address that is the same as the UE. If the MBAP controller determines that UE is detected on multiple beams, MBAP controller may direct a beamforming transceiver to reject UE's registration request in operation412. If the MBAP controller determines that UE is not detected on multiple beams, for example, if only one beamforming transceiver receives or senses UE's registration request, than in operation410, MBAP controller may direct the beamforming transceiver to accept the UE's registration request and allow registration. In operation414, when UE's registration request to the beamforming transceiver is rejected, UE may then attempt to register on the cluster transceiver of the MBAP. This may be because UE is programmed to prefer a primary SSID “A” and a secondary SSID “B”. When UE is rejected from registration with SSID “A”, UE may automatically attempt registration with secondary SSID “B”, which only the cluster transceiver maintains. In operation416, MBAP controller may allow cluster transceiver to transmit data to UE on a different frequency channel than the beamforming transceivers by accepting UE's registration request with the cluster transceiver. Alternatively, UE may initially register on primary SSID “A” with cluster transceiver, and MBAP may allow this registration as well.

FIG. 5is an illustration of UE movement in the geographical coverage of a multibeam access point600, according to embodiments of the invention. UE602amay, for example, start in a SLC area604and move outwards within a beamforming transceiver's antenna path (e.g., beam606). In SLC area604, UE602amay have been initially registered on the cluster transceiver channel 11 as discussed above. As UE602amoves outward, the signal on the cluster transceiver may decrease and UE602amay autonomously decide to roam to another transceiver or access point, in this case the transceiver that supports beam606. In the SLC area604, UE602acould have been on either primary SSID “A” or secondary SSID “B”, but in either case, the MBAP network may support roaming between transceivers. Further, the MBAP600may be 801.11r (fast roaming) capable and if the UE is also 802.11r capable, that protocol may be used. Because of “stickiness” and the extra coverage provided by the cluster antenna, UE602amay stay on cluster channel 11 well into the beam606area. The MBAP600may also be 802.11k capable and if UE1 is also 802.11k capable, that procedure may be used to guide UE602ato a better access point, such as the access point broadcasting beam606.

Another UE602bmay start operation in an area of beam608and move into the SLC area604. The MBAP controller may continue to monitor all data frames from all UE being serviced by the MBAP to determine if a UE is starting to be detected by more than one access point. If detections occur on a regular basis (a period of time which can be adjusted as a tuning parameter) then UE602bmay be forced to move from a beamforming transceiver channel to the cluster transceiver channel 11. UE602bmay be inside the coverage of the cluster transceiver before it enters the SLC area604. However, practically, these boundaries may not be sharp or smooth so the margin between the SLC area and cluster beam coverage may be provided. The margin level may be field tuned.

Another UE602cmay move laterally from one beam610to another beam611. As UE602cmoves, the signal on beam610may decrease and at some point the UE autonomously may decide to roam to another access point, e.g., the access point that supports beam611. This may be standard UE roaming and the MBAP may be 801.11r (fast roaming) capable so that if the UE is also 802.11r capable, that protocol will be used. Again because of “stickiness” UE602cmay stay on beam610for a longer duration than it should. The MBAP will also be 802.11k capable and if UE3 is also 802.11k capable, that procedure may be used to guide UE602cto a better access point.

FIG. 6is a flowchart of a method for tracking UE movement, according to embodiments of the invention. In operation702, every time a data frame sent by any UE registered on one of the narrow beams is received, the MBAP controller may check to see if that UE is also detected on one or more of the other associated beamforming transceivers, meaning the UE has been detected in the SLC area. Every UE that is being served by a beamforming transceiver is tracked. For every data frame sent by a UE, if UE is detected on another beam, this event may be time stamped and the “hit” counter for that UE may be incremented704. If it is not detected, this event may be time stamped and a “miss” counter may incremented706. In operation708, each “hit” and “miss” is logged or tracked for every UE served by the multibeam access point.

In operation710, the data for each UE may be analyzed to determine the statistics of “hits” and “misses” for each UE over a sample time period. In operation720, the hit statistics may be compared to a threshold value. The length (both time of observation and number of detections) and the ratio of hits to misses may be field adjustable and may be set to cause an alarm when the a threshold of hits indicates that UE has moved into the SLC area. In operation740, if the threshold has been reached, MBAP controller may switch UE to a cluster transceiver beam, or allow data transmission between cluster transceiver and UE. Non-limiting examples of decisions may be: i) 50 UE data frames may be observed and 20% or more produced “hits” so the UE may be considered in the SLC area and the UE may be moved to the Cluster beam. ii) 50 UE data frames have been observed and only 2% produced “hits” so the UE may not be moved. The specific values and the thresholds and averaging window may be field adjustable numbers.

FIG. 7is a flowchart of a method for changing the range of the cluster transceiver, according to embodiments of the invention. In operation802, the MBAP controller may collect and log key metrics of all UEs supported by the MBAP. The data logged may include: time stamp, SINR/SNR (Signal to Interference plus Noise Ratio), SLC area hit or miss, channel number, activity level of UE, or UE capability (802.11k, 802.11r, CCX, etc.), for example. The MBAP controller may store the information in a memory for MBAP UE data803.

Periodically, e.g., every minute or every 30 seconds, for example, the UE Assignment Algorithm as shown in804-812may be executed.

In operation804, an algorithm may examine the collected data to determine longer term trends on a UE. A series of statistics may be developed to optimize the stability of the reassignment algorithms. The algorithm may develop medium term utilization statistics for each beam that considers channel loading, average SNIR for each UE, or other statistics.

In operation806, the MBAP may consider whether to change the coverage of the cluster transceiver by increasing or decreasing the transceiver power and the sensitivity of the receiver, so as to maintain uplink/downlink ratios used on other beams. (However, the cluster transceiver coverage may not be reduced below what is required to fully blanket the SLC area). If a cluster antenna pattern change is desired, cluster transceiver power and sensitivity may be changed in operation808and parameters for the change may calculated and sent to the cluster transceiver. Additionally the MBAP configuration file may be updated with this new configuration data and operation804may be executed with the changed configuration data.

If a cluster antenna pattern change is not required, then in operation810, the MBAP may consider whether the UE's channel assignment needs to be changed based on data from operation804. In operation812, the UE channel assignment may be changed if the data supports this decision. If the data does not mandate a change in the UE channel assignment, analysis of UE data may continue in operation804.

FIG. 8is a flowchart of a method describing a UE channel reassignment process, according to embodiments of the invention. This routine may be used when MBAP determines that UE is in an SLC or detected by two or more beamforming transceivers. The method may be used periodically when the MBAP's trend analysis indicates that channel rebalancing could improve overall MBAP performance.

In operation902, MBAP controller may determine if the UE is IEEE 802.11k and CCX (Cisco Compatible Extensions) capable. These protocols may be designed to aid in UE assignments to the appropriate transceivers so as to improve resource management. If UE is 802.11k and CCX compatible, the processor may allow the UE to register with the cluster transceiver and allow the cluster transceiver to transmit data to the UE in accordance with a standard protocol defined by IEEE 802.11k or CCX.

For legacy UE (those that are neither 802.11k or CCX compatible) a deregistration message may be sent to the UE in operation906. This message may cause the UE to scan for a new connection in operation908. In operation909, the controller may determine whether UE is on the cluster transceiver beam. If the UE was being served by one of the multibeams, it would have been connected to primary SSID “A”. Having been deregistered from primary SSID “A” the UE may look for another SSID in its preferred network list. Secondary SSID “B” may be in the UEs preferred network list and is being used as the second SSID by the cluster antenna. The transition from SSID “A” to SSID “B” and vice versa may occur with less service disruption if the UE is 802.11r capable. If UE fails to register on the cluster transceiver channel, MBAP may continue to attempt registration of UE on the cluster transceiver in operation910.

The above approach may enable all UE to be moved out of SLC conditions on to the Cluster antenna as well as being move on to the Cluster antenna as part of channel load balancing.

In the event a legacy UE has been moved into an expanded Cluster Beam area and the MBAP controller would like that UE back on the multibeam, the UE can be “coaxed” to move by the MBAP lowering the power on the Cluster Beam.

It is also possible, by repeating rejection, to move the legacy UE to a different multibeam. This can be accomplished by continuing to reject registration request from the UE until it request registration on the AP channel desired by the MBAP controller. This repeated registration rejection method will not in general be used and only the UE that are either 802.11k or CCX capable will be directly assigned to beams by the MBAP controller

FIG. 9is a flowchart of a method according to embodiments of the invention. In operation10, a user equipment device may transmit data to at least one of plurality of co-located beamforming transceivers. The beamforming transceivers may be part of a multibeam access point and may communicate with UE according to a CSMA/CA protocol, such as IEEE 802.11 for example. In operation12, a multibeam access point processor or controller may monitor whether at least two of the beamforming transceivers have detected the user equipment on a first channel. This may be an indication that the UE is in a side-lobe contamination area, where conflicting transmission between UE's and the beamforming transceivers may cause inefficiencies. In operation14, the processor may allow data transmission between the user equipment and a cluster transceiver on a second channel, based on the monitoring. The processor may, for example, reject a registration request from the UE to one of the beamforming transceivers, so that UE may request registration with the cluster transceiver.

Different embodiments are disclosed herein. Features of certain embodiments may be combined with features of other embodiments; thus certain embodiments may be combinations of features of multiple embodiments.

Embodiments of the invention may include an article such as a computer or processor readable non-transitory storage medium, such as for example a memory, a disk drive, or a USB flash memory device encoding, including or storing instructions, e.g., computer-executable instructions, which when executed by a processor or controller, cause the processor or controller to carry out methods disclosed herein.

In various embodiments, computational modules may be implemented by e.g., processors (e.g., a general purpose computer processor or central processing unit executing software), or digital signal processors (DSPs), or other circuitry. The baseband modem may be implanted, for example, as a DSP. A beamforming matrix can be calculated and implemented for example by software running on general purpose processor. Beamformers, gain controllers, switches, combiners, and phase shifters may be implemented, for example using RF circuitries.

An additional benefit of the invention is the possibility of increasing the utilization of limited radio channels by organizing UE on different radio channels by the quality of their connection to the AP thus increasing the utilization of the radio environment. Specifically the quality of the signal from the UE is measured by the AP and those UEs with stronger signals are assigned to a radio channel with an antenna that has a lower gain and broad azimuth coverage, while the weaker signals are assigned to a higher gain more directional antenna.