WO2017116395A1

WO2017116395A1 - Monitoring of wlan channel availability

Info

Publication number: WO2017116395A1
Application number: PCT/US2015/067675
Authority: WO
Inventors: Congzhen ZHANG; Xuemin Zhang; Moses LI; Xiang FU
Original assignee: Airmagnet Inc.
Priority date: 2015-12-28
Filing date: 2015-12-28
Publication date: 2017-07-06

Abstract

A system for monitoring the availability of channels in a multi-channel WLAN telecommunication system is provided. The system includes a wireless Access Point (AP) configured to provide communication with a mobile station over a plurality of Radio Frequency (RF) channels. The system further includes a plurality of mobile stations (STAs) operating in the plurality of RF channels. The system further includes a network monitoring device communicatively coupled to the WLAN telecommunication system. The network monitoring device is configured and operable to detect a channel acquisition request transmitted between one of the plurality of mobile stations and the wireless AP. The channel acquisition request seeks a first frequency channel. The first frequency channel includes a primary channel and a secondary channel. The network monitoring device is further configured and operable to determine a status of the channel acquisition request for the first frequency channel.

Description

MONITORING OF WLAN CHANNEL AVAILABILITY

FIELD OF THE INVENTION

Embodiments of the present invention relate generally to wireless local area networks (WLA s), and specifically to monitoring of WLAN channel availability.

BACKGROUND OF THE INVENTION

Wireless devices such as smart phones and tablet computing devices continue to proliferate, adding to the total number of mobile devices that seek pervasive Wi-Fi connectivity. Wireless LAN technology continues to evolve as wireless connection speeds advance. Various monitoring tools that monitor wireless networks need therefore be configured to support multiple device types, including legacy 802.11 a/b/g/n devices, and current 802.1 lac devices that enable greater than 1 Gbit/s speeds. The

IEEE 802.1 lac standard supports a more efficient modulation scheme and may bond wider channel bandwidth, up to 160 MHz, to improve link speed. Therefore, the ability to efficiently monitor acquisition of wider channel bandwidths is advantageous to devices utilized for monitoring wireless networks.

SUMMARY OF THE INVENTION

The purpose and advantages of the illustrated embodiments will be set forth in and apparent from the description that follows. Additional advantages of the illustrated embodiments will be realized and attained by the devices, systems and methods particularly pointed out in the written description and claims hereof, as well as from the appended drawings.

In accordance with a purpose of the illustrated embodiments, in one aspect, a system for monitoring the availability of channels in a multi-channel WLAN telecommunication system is provided. The system includes a wireless Access Point (AP) configured to provide communication with a mobile station over a plurality of Radio Frequency (RF) channels. The system further includes a plurality of mobile stations (STAs) operating in the plurality of RF channels. The system further includes a network monitoring device communicatively coupled to the WLAN telecommunication system. The network monitoring device is configured and operable to detect a channel acquisition request transmitted between one of the plurality of mobile stations and the wireless AP. The channel acquisition request seeks a first frequency channel. The first frequency channel includes a primary channel and a secondary channel. The network monitoring device is further configured and operable to determine a status of the channel acquisition request for the first frequency channel.

In another aspect, a computer program product for automatically monitoring the availability of channels in a multi-channel WLAN telecommunication system is provided. The computer program product includes one or more computer-readable storage devices and a plurality of program instructions stored on at least one of the one or more computer- readable storage devices. The plurality of program instructions includes program instructions to detect a channel acquisition request transmitted between one of a plurality of mobile stations and a wireless AP. The channel acquisition request seeks a first frequency channel. The first frequency channel includes a primary channel and a secondary channel. The plurality of program instructions further include program instructions determine a status of the channel acquisition request for the first frequency channel. BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying appendices and/or drawings illustrate various, non-limiting, examples, inventive aspects in accordance with the present disclosure:

FIG. 1 shows an exemplary architecture of a multi-channel WLAN

telecommunication system, according to one embodiment of the present invention;

FIG. 2 is a diagram showing an example of a successful 80MHz channel acquisition, according to an embodiment of the present invention;

FIGS. 3A and 3B are diagrams showing examples of an unsuccessful 80MHz channel acquisition, according to embodiments of the present invention;

FIG. 4 is a flowchart illustrating a method for monitoring the availability of channels in the multi-channel WLAN telecommunication system of FIG. 1, in accordance with an illustrated embodiment of the present invention;

FIG. 5 is a flowchart illustrating detection of 80MHz channel acquisition request in the multi-channel WLAN telecommunication system of FIG. 1, in accordance with an illustrated embodiment of the present invention;

FIGS. 6A-6C are diagrams showing examples of detection of successful 80MHz channel acquisition request, according to embodiments of the present invention;

FIG. 7 is a flowchart illustrating detection of unsuccessful 80MHz channel acquisition in the multi-channel WLAN telecommunication system of FIG. I, in accordance with an illustrated embodiment of the present invention;

FIGS. 8A-8E are diagrams showing examples of detection of unsuccessful 80MHz channel acquisition, according to embodiments of the present invention; FIG. 9 is a flowchart illustrating detection of successful 80MHz channel acquisition in the multi-channel WLAN telecommunication system of FIG. 1, in accordance with an illustrated embodiment of the present invention;

FIGS. lOA-lOC are diagrams showing examples of detection of successful SOMHz channel acquisition, according to embodiments of the present invention;

FIG. 11 is a flowchart illustrating detection of associated AP and ST A pairs with 80MHz channel capability in the multi-channel WLAN telecommunication system of FIG. 1, in accordance with an illustrated embodiment of the present invention; and

FIG. 12 is a block diagram of a computer system configured to implement various methods described herein according to some embodiments of the present invention.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

The present invention is now described more fully with reference to the

accompanying drawings, in which illustrated embodiments of the present invention are shown wherein like reference numerals identify like elements. The present invention is not limited in any way to the illustrated embodiments as the illustrated embodiments described below are merely exemplary of the invention, which can be embodied in various forms, as appreciated by one skilled in the art. Therefore, it is to be understood that any structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative for teaching one skilled in the art to variously employ the present invention. Furthermore, the terms and phrases used herein are not intended to be limiting but rather to provide an understandable description of the invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention, exemplary methods and materials are now described. It must be noted that as used herein and in the appended claims, the singular forms "a", "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a stimulus" includes a plurality of such stimuli and reference to "the signal" includes reference to one or more signals and equivalents thereof known to those skilled in the art, and so forth.

It is to be appreciated the embodiments of this invention as discussed below are preferably a software algorithm, program or code residing on computer useable medium having control logic for enabling execution on a machine having a computer processor. The machine typically includes memory storage configured to provide output from execution of the computer algorithm or program.

As used herein, the term "software" is meant to be synonymous with any code or program that can be in a processor of a host computer, regardless of whether the

implementation is in hardware, firmware or as a software computer product available on a disc, a memory storage device, or for download from a remote machine. The embodiments described herein include such software to implement the equations, relationships and algorithms described below. One skilled in the art will appreciate further features and advantages of the invention based on the below-described embodiments. Accordingly, the invention is not to be limited by what has been particularly shown and described, except as indicated by the appended claims.

In exemplary embodiments, a computer system component may constitute a "module" that is configured and operates to perform certain operations as described herein below. Accordingly, the term "module" should be understood to encompass a tangible entity, be that an entity that is physically constructed, permanently configured (e.g., hardwired) or temporarily configured (e.g. programmed) to operate in a certain manner and to perform certain operations described herein.

The following disclosed embodiments present a method to monitor the acquisition of a channel with a particular frequency designated for synchronizing communication and subsequently communicating the data portion of a communication packet. Some WLAN technologies may use non-contiguous frequency segments for communication, such as two separated 80 MHz segments to form one logical 160 MHz operating channel. Devices within this network may or may not support this operation— i.e., some devices may support only 80 MHz operation while others support 160 MHz operation. The network can function with a mixture of 40MHz, 80 MHz and 160 MHz devices, and can provide a means for a 160 MHz- capable device (which could be a STA or the AP) to temporarily declare itself capable of only 80 MHz operation while still maintaining operation within the network.

In particular, WLAN systems, such as for example 802.11 ac systems (that is, systems that support an Institute of Electrical and Electronics Engineers (IEEE) 802.11 ac standard), may in some instances come in two types: systems including non-contiguous channels, and those including contiguous channels. Non-contiguous channels among others allow flexibility in responding to the configuration of interfering/competing networks and radars to be avoided, essentially by improving the probability that a device may find a workable 40 MHz+40 MHz or 80 MHz+80 MHz non-contiguous channel versus 80 MHz and 160 MHz contiguous channels, respectively. For example, according to an 802.11 ac standard, a noncontiguous 80 MHz transmission may be established whose frequency spectrum consists of a first segment transmitted using one 40 MHz channel, and a second segment transmitted using another 40 MHz channel, possibly non-adjacent in frequency. Thus, 80 MHz non-contiguous devices according to some embodiments could operate with 80 MHz contiguous or non- contiguous networks. However, when radio propagation path quality becomes inferior, communication errors increase, and both APs and STAs may switch to other operating channels, such as channels having bandwidth of 40MHz or even 20 MHz, to communicate with each other. One illustrative embodiment of the method disclosed herein monitors the acquisition of the 80MHz bonding channel and raises alarms to report the radio environment deterioration when either AP or STA is unable to obtain the requested channel bandwidth.

In accordance with an illustrated embodiment of the present invention, reference is now made to FIG. 1 which is an exemplary and non- limiting diagram illustrating a network architecture to which embodiments of the present invention are applicable. In the illustrated embodiment of FIG. 1, wireless communication system 100 can include a network of one or more access points (APs) 104 that are configured to communicate with one or more wireless stations (STAs) 102. An AP 104 can emit radio signals that carry management information, control information or users' data to one or more wireless stations 102. An STA can also transmit radio signals to an AP in the same frequency channel via time division duplexing (TDD) or in different frequency via frequency division duplexing (FDD).

It is to be understood and appreciated in IEEE 802.1 lac environment, wireless stations (also called stations, e.g., STAs 102a and STAs 102b in FIG. 1) associated in the radio coverage area establish a BSS (basic service set) and provide basic service of WLAN. A BSS built around an AP is called an infrastructure BSS. FIG. 1 illustrates an example of two infrastructure BSSes formed by two APs. The first BSS contains a first AP 104a and a first plurality of STAs 102a. The first AP 104a maintains associations with the STAs 102a. The second BSS contains a second AP 104b and a second plurality of STAs 102b. The second AP 104b maintains associations with the second plurality of STAs 102b.

Advantageously, the wireless communication system 100 further includes a WLAN monitoring system 106 that is able to monitor wireless local area network signals. In one embodiment, the monitoring system 106 comprises a plurality of WLAN signal detectors 108, a monitoring computing device 110 communicatively coupled to the plurality of signal detectors 108 and a database 112 for storing information related to at least WLAN devices capabilities and associations. The monitoring system 106 may include any number of signal detector elements 108. Thus, in one embodiment, the detector elements 106 may include two or more receive elements (e.g., multiple antennas) for receiving wireless

signals over the air interface.

In various embodiments, the monitoring computing device 110 may comprise any suitable computing device, such as, but not limited to, a personal computer (PC), laptop computer, smart phone or other computing device having a processor, a memory and a user interface. The monitoring computing device 110 is configured to run a software component to monitor channel availability (such as, but not limited to 80 MHz channel availability) in the wireless communication system 100. The monitoring computing device 110 also

communicates with the database 112 for logging and accessing various data associated with communications (e.g., AP-STA pairing information). The database 112 may be a single database, table, or list, or a combination of databases, tables, or lists. In various embodiments, the database 112 can be a standalone database or it can be a component of the monitoring computing device 110.

FIG. 2 is a diagram illustrating an example of a successful channel acquisition, according to an embodiment of the present invention. As previously noted, the different

STAs 102a, 102b may operate at least partly on different frequency channels. IEEE 802.11η specification specifies a data transmission mode that includes 20 MHz wide primary and secondary channels. The primary channel is used in all data transmissions with clients supporting only the 20 MHz mode and with clients supporting higher bandwidths. A further definition in 802.1 In is that the primary and secondary channels are adjacent. The 802.1 In specification also defines a mode in which a STA 102 may, in addition to the primary channel, occupy one secondary which results in a maximum bandwidth of 40 MHz. IEEE 802.1 lac task group extends such an operation model to provide for wider bandwidths by allowing both the primary and secondary channels to include up to four 20MHz subchannels, thus resulting in bandwidths of 20 MHz, 40 MHz, 80 MHz and 160 MHz. A 40 MHz transmission band may be formed by two contiguous 20 MHz bands and an 80 MHz transmission band may be formed by two contiguous 40 MHz bands. However, a 160 MHz band may be formed by two contiguous or non-contiguous 80 MHz bands.

Different BSSs may employ different bonding channel bandwidths.

Next, a channel allocation mechanism in the wireless communication system 100 will be described according to embodiments of the present invention. Although the embodiments described below relate to a wireless system using a bonding channel in which contiguous 4 subchannels having a bandwidth of 20 MHz are combined (i.e., a bonding channel having a channel bandwidth of 80MHz), this is for exemplary purposes only. The embodiments described below can equally apply to a wireless system including a plurality of subchannels (e.g., up to eight subchannels), which is apparent to those skilled in the art. In addition, the embodiments of the present invention are not limited to the wireless telecommunication system whose subchannel has a bandwidth of 20 MHz.

In the embodiment illustrated in FIG. 2, the bonding channel having bandwidth of 80MHz includes a primary 40MHz channel 202 and a secondary 40 MHz channel 204. As shown in FIG. 2, both the primary channel 202 and secondary channel 204 may further comprise two contiguous 20 MHz subchannels. Notably, the wireless network 100 employs request-to-send (RTS) signaling mechanism to protect data transmissions.

According to RTS signaling mechanism, a wireless device (e.g., STA 102) must transmit a request-to-send frame 206 before transmitting a data frame 210. In other words, a sending device (node) may use an RTS frame 206 to announce an intention to transmit a data frame 210, and the RTS frame 206 may be addressed to a recipient of the data frame 210. Upon receiving the RTS frame 206, the recipient (e.g., AP 104) may respond with a clear-to-send (CTS) frame 208 if the data transmission is acceptable to it (e.g., if the channel is sensed to be free). On the other hand, the recipient may refrain from transmitting the CTS frame 208 and, upon receiving no CTS frame 208, the sending node 102 may refrain from data transmission and avoid collision, thus avoiding collision and improving overall performance. Upon receiving the CTS frame 208, the sending node 102 may transmit the data frame 210 under the protection caused by the prior RTS frame 206. This mechanism avoids the hidden node problems because the recipient node announces the

coming data transmission with the transmission of the CTS frame 208.

As shown in FIG. 2, the RTS frame 206 is sent over four 20 MHz subchannels. The recipient node 104 receiving the RTS frame 206 sends back a CTS frame 208, in which all of the four 20MHz subchannels (e.g., both the primary channel 202 and secondary channel 204), are indicated as being available to receive data by the recipient node 104. It is noted that in this scenario, subsequent data frames 210 or the like are generally transmitted by the STA 102 using the entire 80 MHz wide bonding channel. In response to receiving the data frame 210, the AP 104 sends a Block acknowledgment (ACK) frame 212 on each of the four subchannels.

FIGS. 3A and 3B are diagrams showing examples of an unsuccessful 80MHz channel acquisition, according to embodiments of the present invention. In a first unsuccessful channel acquisition case, shown in FIG. 3 A, the recipient node 104 receiving the RTS frame 206 on all four subchannels sends back the CTS frame 208 in which only two of the four 20MHz subchannels (the primary channel 202), are indicated as being available to receive data by the recipient node 104. Accordingly, subsequent data frame 210 is transmitted by the STA 102 using only the primary channel having bandwidth of 40 MHz. In response to receiving the data frame 210, the recipient node 104 sends a Block ACK frame 212 over each subchannel of the primary channel 202. Thus, FIG. 3A illustrates that in this case the secondary channel 204 cannot be acquired (visually depicted by a box 302a) in response to a channel acquisition request (i.e., the RTS frames 206) sent by an original sender (e.g., STA 102).

In a second scenario, shown in FIG. 3B, the recipient node 104 again

receives the RTS frame 206 on all four subchannels and sends back the CTS frame 208 in which only the primary 20MHz channel 202 is indicated as being available to receive data by the recipient node 104. In this case, the subsequent data frame 210 is transmitted by the STA 102 using only the 20MHz channel 202. In response to receiving the data frame 210, the recipient node 104 sends a Block ACK frame 212 only over the primary 20MHz primary channel 202. The remaining subchannels cannot be acquired as visually depicted by a box 302b.

FIGS. 4, 5, 7, 9 and 11 are flowcharts illustrating a method for monitoring the availability of channels in the multi-channel WLAN telecommunication system of FIG. 1, in accordance with an illustrated embodiment of the present invention. Before turning to description of FIGS. 4, 5, 7, 9 and 11, it is noted that the flow diagrams in these figures show examples in which operational steps are carried out in a particular order, as indicated by the lines connecting the blocks, but the various steps shown in these diagrams can be performed in any order, or in any combination or sub-combination. It should be appreciated that in some embodiments some of the steps described below may be combined into a single step. In some embodiments, one or more additional steps may be performed. As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a method or computer program product. In some embodiments, the method described below may be performed, at least in part, by one or more components of the monitoring system 106, such as, but not limited to, the monitoring computing device 110.

Starting with FIG. 4, there is illustrated a high level overview of a channel acquisition detection mechanism that may be implemented by the monitoring computing device 110. In one embodiment, the software component running on the monitoring computing device 110, hereafter referred to as a monitoring engine, may employ status flags to indicate when particular boundary conditions (such as, for example, failure count exceeding a predefined threshold ) are present. Thus, at step 402, the monitoring engine begins monitoring by setting a channel acquisition alarm flag to an "inactive" status. Notably, the active status of the alarm flag may indicate a significant number of channel acquisition failures in the wireless telecommunications system 100 being monitored. A threshold value indicating this significant number of failures may be a user configurable predefined parameter in the monitoring system 106 shown in FIG. 1. Next, at step 404, the monitoring engine may reset the total failure counter to a predetermined reset value, such as minus one. At step 406, the monitoring engine increments the total failure counter. A determination is made at step 408 whether the total failure counter reached the predefined threshold value indicating that an alarm needs to be raised. If the threshold value has been reached (decision block 408, "yes" branch), the monitoring engine resets the status of the channel acquisition alarm flag to "active" at step 410 and returns to step 404 to start another monitoring cycle. According to an embodiment of the present invention, when the acquisition alarm flag becomes "active" in step 410, the monitoring engine may report the radio environment deterioration to a user via the monitoring engine's user interface or any other suitable notification mechanism. For example, the monitoring engine may generate one or more ad hoc user alert notifications indicating a number of APs and/or STAs unable to obtain requested channel bandwidths. In response to determining that the total failure counter has not reached the predefined threshold yet (decision block 408, "no" branch), at step 412, the monitoring engine performs detection of channel acquisition requests in the monitored wireless communication system 100.

Referring now to FIG. 5, there is illustrated a flowchart depicting a channel acquisition request detection method in the multi-channel WLAN telecommunication system of FIG. 1, in accordance with an illustrated embodiment of the present invention. Continuing with a non-limiting example where a bonding channel comprises four combined contiguous subchannels having a bandwidth of 20 MHz, in one embodiment, the monitoring engine may start monitoring only a secondary channel of the bonding channel at step 502. A

determination is made at step 504 whether the RTS frame is detected, as shown in FIGS. 6A- 6C.

As shown in FIG. 6A, in one embodiment, the monitoring engine may monitor only 20 MHz subchannels of the secondary channel 204. Finding an RTS frame 208a or 208b on any of the two subchannels would be a sufficient indication of a channel acquisition request. Alternatively, as shown in FIG. 6B, the monitoring engine may detect a channel acquisition request by finding the RTS frames 208a and 208b on each of the 20MHz subchannels comprising the secondary channel 204. In yet another embodiment, illustrated in FIG. 6C, the monitoring engine may also detect a channel acquisition request by monitoring both the primary 202 and the secondary 204 channels (step 502) and by finding combined four RTS frames 208a- 208d, one on each subchannel. It will be apparent to those skilled in the art, that while any of the detection techniques illustrated in FIGS. 6A-6C may be implemented by the monitoring engine, the embodiment illustrated in FIG. 6A represents the most efficient approach.

Referring back to FIG. 5, in response to detecting at least one RTS frame 208 on at least one subchannel (decision block 504, "yes" branch), the monitoring engine may make the positive determination that a channel acquisition request transmitted by a sending node (e.g., one of the plurality of STAs 102a) has been detected (step 506). Now referring back to FIG. 4, if the monitoring engine detects a channel acquisition request (decision block 414, "yes" branch), at step 422, the monitoring engine continues monitoring the communication session between the sending node 102 and the recipient node 104 and attempts to detect unsuccessful channel acquisition for the requested bonding channel.

Referring now to FIG. 7, there is illustrated a flowchart depicting detection of unsuccessful 80MHz channel acquisition in the multi-channel WLAN telecommunication system of FIG. 1, in accordance with an illustrated embodiment of the present invention. At step 702, the monitoring engine may first determine whether the data frame 210 has been transmitted exclusively over the primary channel 202 instead of the entire

bonding channel having the bandwidth of 80MHz, as shown in FIG. 8A. Since the primary channel 202 has bandwidth of 40MHz and the channel acquisition request in the form of RTS frames 206 requested 80MHz wide bonding channel, the data frame 210 detected exclusively on the primary channel 202 indicates that the channel acquisition request was not granted 302a by the recipient node with respect to the secondary channel 204.

If the monitoring engine does not detect the data frame 210 exclusively on the primary channel 202 (decision block 702, "no" branch), at step 704, a determination is made whether the Block ACK frames 212 have been transmitted exclusively via the primary 40 MHz channel 202, as shown in FIG. 8B. If the monitoring engine does not detect any Block ACK frames 212 following the RTS frames 206 on all four subchannels, the monitoring engine in this scenario can definitely conclude that the channel acquisition request was not granted 302a by the recipient node with respect to the secondary channel 204.

If the monitoring engine does not detect the Block ACK frames 212 exclusively on both subchannels of the primary channel 202 (decision block 704, "no" branch), at step 706, a determination is made whether the data frame 210 has been transmitted via the primary 20MHz channel 802 only instead of the entire bonding channel having the bandwidth of 80MHz, as shown in FIG. 8C. Since the channel 802 has bandwidth of 20MHz and the channel acquisition request in the form of RTS frames 206 requested 80MHz bonding channel, the data frame 210 detected exclusively on the subchannel 802 indicates that the channel acquisition request was not granted 302b by the recipient node with respect to other subchannels.

Furthermore, if the monitoring engine does not detect the data frame 210 exclusively on the primary 20MHz channel (decision block 706, "no" branch), at step 708, a

determination is made whether the Block ACK frames 212 have been transmitted exclusively via the primary 20MHz channel 802, as shown in FIG. 8D. If the monitoring engine only detects a single Block ACK frame 212 on the primary 20MHz channel 802 following the RTS frames 206 on all four subchannels, the monitoring engine in this scenario can definitely conclude that the channel acquisition request was not granted 302b by the recipient with respect to three other subchannels.

According to an embodiment of the present invention, if the channel acquisition failure analysis performed in steps 702-708 evaluates to true (decision blocks 702-708, "yes" branches), at step 710, the monitoring engine makes a positive determination of unsuccessful 80MHz channel acquisition in the multi-channel WLAN telecommunication system of FIG. 1. According to an alternative embodiment, if the monitoring engine determines that both the sender 102a and recipient 104a (i.e., STA - AP pair) have 80 MHz channel capability but communicate with each other via one or more subchannels having a combined bandwidth below the requested bandwidth, as shown in FIG. 8E, the monitoring engine in this case can also make a positive determination of unsuccessful 80MHz channel acquisition.

Now referring back to FIG. 4, if the monitoring engine detects a channel acquisition failure (decision block 424, "yes" branch), it returns back to step 406, increments the total failure counter and optionally repeats the steps 408-414 and 422 for other bonding communication channels in the multi-channel WLAN telecommunication system of FIG. 1. In response to failing to detect a channel acquisition failure for a monitored bonding channel (decision block 424, "no" branch), at step 426, the monitoring engine can optionally make a positive detection of successful channel acquisition for the monitored bonding channel.

Referring now to FIG. 9, there is illustrated a flowchart depicting detection of a successful 80MHz channel acquisition in the multi-channel WLAN telecommunication system of FIG. 1, in accordance with an illustrated embodiment of the present invention. At step 902, the monitoring engine may first determine whether the CTS frame 208 is detected on each 20MHz subchannel included in the primary 202 and secondary 204 channels, as shown in FIG. 10A. If the monitoring engine does not detect the CTS frames 208 on each subchannel (decision block 902, "no" branch), at step 904, a determination is made whether the data frame 210 has been transmitted using entire 80 MHz bandwidth, as shown in FIG. 10B. If the monitoring engine does not successfully detect the data frame 210 transmission using the entire bonding channel (decision block 904, "No" branch), at step 906, yet another determination is made whether the Block ACK frame 212 is detected on any subchannel of the secondary channel 204, as shown in FIG. IOC. According to an embodiment of the present invention, if the channel acquisition analysis performed in any of the steps 902-906 evaluates to true (decision blocks 902-906, "yes" branches), at step 908, the monitoring engine makes a positive determination of a successful 80MHz channel acquisition in the multi-channel WLAN telecommunication system of FIG. 1.

Now referring back to FIG. 4 yet again, if the monitoring engine detects a successful channel acquisition (decision block 428, "yes" branch), it returns back to step 402, resets the status of the channel acquisition alarm flag back to "inactive" and optionally repeats the steps 404-414 and 422-426 for other bonding communication channels in the multi-channel WLAN telecommunication system of FIG. 1. In response to failing to detect any 80 MHz channel acquisition requests (decision block 414, "no" branch), at step 416, the monitoring engine can detect pairs of nodes that communicate with each other and have 80MHz communication capability.

FIG. 11 is a flowchart illustrating detection of AP and STA pairs with 80MHz channel capability in the multi-channel WLAN telecommunication system of FIG. 1, in accordance with an illustrated embodiment of the present invention. At step 1102, the monitoring engine may begin detection by capturing a series of frames transmitted over the air interface in one or more monitored BSS using the plurality of WLAN signal detectors 108, for example. Next, at step 1104, the monitoring engine analyzes the captured frames to identify communication nodes having the communication capability of interest. In one embodiment, such communication capabilities can be readily determined based on information in the beacon frames, association request/response frames, reassociation request/reassociation response and/or probe request/probe response, for example. Once the monitoring engine identifies all STAs 102 and all APs 104 having the communication capability of interest (i.e., 80 MHz), at step 1106, the monitoring engine may continue the analysis by pairing STAs 102 and APs 104 that communicate with each other based on the information captured during the association, re-association and/or data transmission procedure for each monitored communication session.

At step 1108, according to an embodiment of the present invention, the monitoring engine stores at least some of the communication session related information, such as, but not limited to, AP-STA pairings in the database 112 depicted in FIG. 1. Now referring back to FIG. 4, once the communicating nodes are paired up by the monitoring engine, at step 418, the monitoring engine may determine whether any data frames are transmitted via one or more subchannels having a combined bandwidth below the desired bandwidth, as shown in FIG. 8E. In response to detecting no data frames (decision block 418, "no" branch), the monitoring engine returns back to step 412 and attempts once again to detect any channel acquisition requests. If such data frames are detected and the pair exchanging the data frames is included in the database as having higher bandwidth capabilities (decision block 420, "yes" branch), the monitoring engine counts such transmissions as channel acquisition failures and returns back to step 406 to increase the total failure counter, as shown in FIG. 4.

In summary, various embodiments of the present invention disclose a novel approach to monitor acquisition of various channel bandwidths by wireless devices in multi-channel WLAN telecommunication systems. Although the embodiments described above are directed to a wireless system using a bonding channel in which four contiguous subchannels having a bandwidth of 20 MHz are combined (i.e., a bonding channel having a channel bandwidth of 80MHz), this is for exemplary purposes only. The embodiments described above can equally apply to a wireless system having a bonding channel bandwidth of 40MHz or 160MHz, for example. Furthermore, the above description equally applies to non-contiguous, such as, but not limited to, 80 MHz+80 MHz non-contiguous channel. It will be apparent to those skilled in the art, that if the bandwidth of the monitored bonding channel is 40MHz, both the primary 202 and secondary 204 channels have bandwidth of 20MHz. In such system the monitoring engine is enabled to: 1) detect a channel acquisition request when the RTS frame 208 is detected on at least one of the primary 202 and secondary 204 channels; 2) detect a failure of 40MHz channel acquisition when the data frame 210 or Block ACK frame 212 is detected exclusively on the primary channel 202; 3) detect a successful acquisition of 40MHz channel when the CTS 208, data 210 or Block ACK 212 frames are detected on both the primary 202 and secondary 204 channels or when the Block ACK frame 212 is detected at least on the secondary channel 204. On the other hand, if the bandwidth of the monitored bonding channel is 160MHz, both the primary 202 and secondary 204 channels have bandwidth of 80MHz and each includes four different 20MHz subchannels. In such system, the monitoring engine is enabled to: 1) detect a channel acquisition request when the RTS frame 208 is detected on at least one of the subchannels included in the secondary channel 204; 2) detect a failure of 160MHz channel acquisition when the data frame 210 or Block ACK frame 212 is detected exclusively on at least one of the subchannels included in the primary channel 202; 3) detect a successful acquisition of 160MHz channel when the CTS 208, data 210 or Block ACK 212 frames are detected on all subchannels of both the primary 202 and secondary 204 channels or when the Block ACK frame 212 is detected on at least one subchannel of the secondary channel 204.

As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system, method or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a "circuit," "module" or "system." Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon.

Any combination of one or more computer readable medium(s) may be utilized. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.

A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.

Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN), a wide area network (WAN) or WLAN, or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).

Aspects of the present invention are described above with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program

instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for

implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks.

The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. Embodiments of the network monitoring system may be implemented or executed by one or more computer systems. One such computer system, the monitoring computing device 110 is illustrated in FIG. 12. In various embodiments, network monitoring system 110 may be a server, a distributed computer system, a workstation, a network computer, a desktop computer, a laptop, a tablet, a wireless device or the like.

The monitoring computing device 110 is only one example of a suitable system and is not intended to suggest any limitation as to the scope of use or functionality of embodiments of the invention described herein. Regardless, the monitoring computing device 110 is capable of being implemented and/or performing any of the functionality set forth hereinabove.

The monitoring computing device 110 is operational with numerous other general purpose or special purpose computing system environments or configurations. Examples of well-known computing systems, environments, and/or configurations that may be suitable for use with the network monitoring system 100 include, but are not limited to, personal computer systems, server computer systems, thin clients, thick clients, hand-held or laptop devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, network PCs, minicomputer systems, mainframe computer systems, and distributed data processing environments that include any of the above systems or devices, and the like.

The components of the monitoring computing device 110 may be described in the general context of computer system-executable instructions, such as program modules, being executed by a computer system. Generally, program modules may include routines, programs, objects, components, logic, data structures, and so on that perform particular tasks or implement particular abstract data types. The monitoring computing device 110 may be practiced in distributed data processing environments where tasks are performed by processing devices that are linked through a communications network. In a distributed data processing environment, program modules may be located in both local and remote computer system storage media including memory storage devices.

The monitoring computing device 110 is shown in FIG. 12 in the form of a general- purpose computing device. The components of the monitoring computing device 110 may include, but are not limited to, one or more processors or processing units 1216, a system memory 1228, and a bus 1218 that couples various system components including the system memory 1228 to the processor 1216.

The bus 1218 represents one or more of any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus.

The monitoring computing device 110 typically includes a variety of computer system readable media. Such media may be any available media that is accessible by the monitoring computing device 110, and it includes both volatile and non- volatile media, removable and non-removable media.

The system memory 1228 can include computer system readable media in the form of volatile memory, such as a random access memory (RAM) 1230 and/or a cache memory 1232. The monitoring computing device 110 may further include other removable/nonremovable, volatile/non-volatile computer system storage media. By way of example only, a storage system 1234 can be provided for reading from and writing to a non-removable, nonvolatile magnetic media (not shown and typically called a "hard drive"). Although not shown, a magnetic disk drive for reading from and writing to a removable, non- volatile magnetic disk (e.g., a "floppy disk"), and an optical disk drive for reading from or writing to a removable, non-volatile optical disk such as a CD-ROM, DVD-ROM or other optical media can be provided. In such instances, each can be connected to the bus 1218 by one or more data media interfaces. As will be further depicted and described below, the memory 1228 may include at least one program product having a set (e.g., at least one) of program modules that are configured to carry out the functions of embodiments of the invention.

Program/utility 1240, having a set (at least one) of program modules 1215 (such as the monitoring engine) may be stored in the memory 1228 by way of example, and not limitation, as well as an operating system, one or more application programs, other program modules, and program data. Each of the operating system, one or more application programs, other program modules, and program data or some combination thereof, may include an implementation of a networking environment. Program modules generally carry out the functions and/or methodologies of embodiments of the invention as described herein.

The monitoring computing device 110 may also communicate with one or more external devices 1214 such as a keyboard, a pointing device, a display, etc.; one or more devices that enable a user to interact with the monitoring computing device 110; and/or any devices (e.g., network card, modem, etc.) that enable the monitoring computing device 110 to communicate with one or more other computing devices. Such communication can occur via Input/Output (I/O) interfaces 1222. Still yet, the monitoring computing device 110 can communicate with one or more networks such as a LAN, a WAN, a WLAN and/or a public network (e.g., the Internet) via a network adapter 1220. As depicted, the network adapter 1220 communicates with the other components of monitoring computing device 110 via the bus 1218. It should be understood that although not shown, other hardware and/or software components could be used in conjunction with the monitoring computing device 110.

Examples, include, but are not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data archival storage systems, etc.

The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware -based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

The descriptions of the various embodiments of the present invention have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

What is claimed is:

1. A system for monitoring the availability of channels in a multi-channel WLAN telecommunication system, the system comprising:

a wireless access point (AP) configured to provide communication with a mobile station over a plurality of Radio Frequency (RF) channels;

a plurality of mobile stations (STAs) operating in the plurality of RF channels; and a network monitoring device communicatively coupled to the WLAN telecommunication system, wherein the one or more network monitoring devices are configured and operable to:

detect a channel acquisition request transmitted between one of the plurality of mobile stations and the wireless AP, the channel acquisition request requesting a first frequency channel, the first frequency channel comprises a primary channel and a secondary channel; and

determine a status of the channel acquisition request for the first frequency channel.

2. The system as recited in claim 1, wherein the primary channel comprises at least one 20 MHz subchannel and wherein the secondary channel comprises at least one 20 MHz subchannel.

3. The system as recited in claim 2, wherein the first frequency channel has a bandwidth of 40MHz, 80MHz, or 160MHz.

4. The system as recited in claim 2, wherein the primary channel and the secondary channel comprise non-contiguous frequency channels.

- 26 - f

5. The system as recited in claim 2, wherein the network monitoring device is further configured and operable to detect the channel acquisition request by monitoring the primary channel and the secondary channel and by detecting a request-to-send (RTS) frame transmitted between the AP and one of the plurality of STAs on each of the subchannels of the primary channel and the secondary channel.

6. The system as recited in claim 2, wherein the network monitoring device is further configured and operable to detect the channel acquisition request by monitoring the secondary channel and by detecting a request-to-send (RTS) frame transmitted between the AP and one of the plurality of STAs on at least one of the subchannels of the secondary channel.

7. The system as recited in claim 2, wherein the network monitoring device is further configured and operable to determine successful channel acquisition by monitoring the primary channel and the secondary channel and by detecting a clear-to-send (CTS) frame transmitted between the AP and one of the plurality of STAs on each of the subchannels of the primary channel and the secondary channel.

8. The system as recited in claim 1, wherein the network monitoring device is further configured and operable to determine successful channel acquisition by monitoring the first frequency channel and by detecting a data frame transmitted between the AP and one of the plurality of STAs using the requested bandwidth of the first frequency channel.

9. The system as recited in claim 2, wherein the network monitoring device is further configured and operable to determine successful channel acquisition by monitoring the secondary channel and by detecting an acknowledgment frame transmitted between the AP and one of the plurality of STAs on at least one of the subchannels of the secondary channel.

10. The system as recited in claim 2, wherein the network monitoring device is further configured and operable to determine unsuccessful channel acquisition by monitoring the primary channel and the secondary channel and by detecting acknowledgment transmitted between the AP and one of the plurality of STAs exclusively on the primary channel.

11. The system as recited in claim 2, wherein the network monitoring device is further configured and operable to determine unsuccessful channel acquisition by monitoring the primary channel and the secondary channel and by detecting a data frame transmitted between the AP and one of the plurality of STAs using a frequency band substantially lower than the requested first frequency channel bandwidth.

12. The system as recited in claim 1, wherein the network monitoring device is further configured and operable to detect deteriorated wireless environment by detecting the capabilities of the AP and the plurality of STAs and by comparing the detected capabilities with a bandwidth utilized by the AP and the plurality of STAs for transmitting a plurality of data frames.

13. The system as recited in claim 1, wherein the network monitoring device is further configured and operable to send an alarm notification based on the determined status of the channel acquisition request.

14. A computer program product for automatically monitoring the availability of channels in a multi-channel WLAN telecommunication system, the computer program product comprising: one or more computer-readable storage devices and a plurality of program instructions stored on at least one of the one or more computer-readable storage devices, the plurality of program instructions comprising:

program instructions to detect a channel acquisition request transmitted between one of a plurality of mobile stations and a wireless AP, the channel acquisition request requesting a first frequency channel, the first frequency channel comprises a primary channel and a secondary channel; and

program instructions determine a status of the channel acquisition request for the first frequency channel.

15. The computer program product as recited in claim 14, wherein the primary channel comprises at least one 20 MHz subchannel and wherein the secondary channel comprises at least one 20 MHz subchannel.

16. The computer program product as recited in claim 15, wherein the first frequency channel has a bandwidth of 40MHz, 80MHz, or 160MHz.

- 29 - f

17. The computer program product as recited in claim 15, wherein the primary channel and the secondary channel comprise non-contiguous frequency channels.

18. The computer program product as recited in claim 15, wherein the plurality of program instructions further comprises program instructions to detect the channel acquisition request by monitoring the primary channel and the secondary channel and by detecting a request-to-send (RTS) frame transmitted between the AP and one of the plurality of ST As on each of the subchannels of the primary channel and the secondary channel.

19. The computer program product as recited in claim 15, wherein the plurality of program instructions further comprises program instructions to determine successful channel acquisition by monitoring the primary channel and the secondary channel and by detecting a clear-to- send (CTS) frame transmitted between the AP and one of the plurality of ST As on each of the subchannels of the primary channel and the secondary channel.

20. The computer program product as recited in claim 15, wherein the plurality of program instructions further comprises program instructions to determine unsuccessful channel acquisition by monitoring the first frequency channel and by detecting a data frame transmitted between the AP and one of the plurality of STAs using the requested bandwidth of the first frequency channel.