JP2018196129A - Wireless communication method and apparatus - Google Patents

Abstract

Provided is a wireless communication method and apparatus in which each access point performs distributed and independent channel selection. An access point includes a wireless network interface that is switchable between a plurality of wireless communication channels. The access point monitors each of multiple monitored channels from multiple channels over a period of time, identifies transmissions that may interfere on the monitored channel, and calculates an interference metric for the monitored channel. Remember. Compare the stored interference metrics for multiple monitored channels and select the monitored channel with the lowest interference metric as the communication channel. [Selection] Figure 3

Description

  Embodiments described herein generally relate to wireless communication methods and apparatus, and more particularly to channel selection by access points in a wireless network.

  Wireless local area network (WLAN) technology has evolved significantly over the last decade and continues to be useful, but there are scenarios where it is struggling to achieve acceptable performance for most basic services. Specifically, in scenarios that are deployed very densely, performance can degrade. One of the main causes of this degradation is the overcrowding of devices in the unlicensed band where the WLAN normally operates. In addition to the problem, not only the number of users but also access points (APs) that provide services to users are increasing. As a result, coverage areas overlap in dense areas.

  The problem that arises in such a deployment is how to select the channel that the AP operates. Particularly in unplanned installations, an AP has little or no control over a large number of APs operating in the vicinity of their radio, each often selecting independently.

  Embodiments will be described below with reference to the drawings.

1 illustrates a wireless network according to one embodiment. FIG. The figure which shows the access point by one Embodiment. 1 is a diagram illustrating a wireless communication method according to an embodiment. FIG. FIG. 4 is a diagram illustrating a start procedure in an access point according to an embodiment. The figure which shows the data memorize | stored in the memory of the access point in one Embodiment. The figure which shows the channel scanning method by one Embodiment. The figure which shows the method of switching the channel in one Embodiment. 8a is a diagram showing the vicinity of the network according to one embodiment, and 8b is a diagram showing the vicinity of the network according to one embodiment. The figure which shows the access point by one Embodiment.

  In one embodiment, a method of wireless communication at an access point of a wireless network is disclosed. The access point comprises a wireless network interface configured to be switchable between a plurality of wireless communication channels. The method monitors each of a plurality of monitored channels from a plurality of channels, wherein monitoring the monitored channels configures the wireless network interface to monitor the monitored channels; Identifying transmissions that may interfere on the monitored channel and determining a count of transmissions that may interfere on the monitored channel; and possibly interference on the monitored channel Storing interference for a plurality of monitored channels comprising: calculating an interference metric for the monitored channel as a function of at least a count of a transmission; and storing an interference metric for the monitored channel Compare metrics and select monitored channel with lowest interference metric as communication channel DOO DOO, and a configuring the access point to communicate via a wireless network using the selected communication channel.

  In one embodiment, monitoring the monitored channel further comprises determining a measure of received signal strength for each potentially interfered transmission identified on the monitored channel, wherein the interference metric is A function of the count of potentially interfering transmissions on the monitored channel and the sum of indications of received signal strength indicators for each potentially interfering transmission on the monitored channel.

  In one embodiment, identifying a potentially interfering transmission on the monitored channel includes receiving the transmission; determining the destination of the received transmission; and when the destination is not an access point, Identifying the transmission as a transmission that may interfere.

  In one embodiment, communicating via a wireless network using a selected communication channel comprises communicating using a wireless network interface.

  In one embodiment, the access point comprises a first wireless network interface and a second wireless network interface, each configured to be switchable between a plurality of wireless communication channels, each of the plurality of monitored channels. Monitoring comprises switching the first wireless network interface to each monitored channel from a plurality of monitored channels, and communicating via the wireless network using the selected communication channel is second Switching the wireless network interface to the selected communication channel.

  In one embodiment, the interference metric is the average signal strength of transmissions that may interfere on the monitored channel.

  In one embodiment, the interference metric is a moving average of the signal strength of transmissions that may interfere on the monitored channel.

  In one embodiment, the method further comprises transmitting an indication of an interference metric for the selected communication channel on the selected communication channel.

  In one embodiment, a computer-readable carrier medium carrying processor-executable instructions that, when executed on a processor, cause the processor to perform the wireless communication method according to the above embodiments.

  In one embodiment, an access point for a wireless network is disclosed. An access point identifies a first wireless network interface configured to be switchable between a plurality of wireless communication channels; and identifies potentially interfering transmissions on monitored channels of the plurality of wireless communication channels; An identification module configured to determine a count of potentially interfering transmissions on the monitored channel; an interference metric for the monitored channel as a function of at least a count of potentially interfering transmissions on the monitored channel; Using a communication channel selected by comparing the interference metrics stored in the memory; a calculation module configured to calculate an interference metric for each monitored channel; Through the wireless network to the access point And a communication module configured to Shin.

  In one embodiment, the communication module is configured to communicate on the selected communication channel using the first wireless network interface.

  In one embodiment, the access point further comprises a second wireless network interface, and the communication module is configured to communicate on the selected communication channel using the second wireless network interface.

  In one embodiment, the identification module further determines the signal strength of the identified potentially interfering transmissions on the monitored channel and determines the sum of the signal strengths of the potentially interfering transmissions on the monitored channel. The computing module is configured to determine an interference metric for the monitored channel as a function of a count of potentially interfering transmissions and a sum of signal strengths of potentially interfering transmissions on the monitored channel. Is configured to calculate

  In one embodiment, the identification module determines the destination of the received transmission and, when the destination is not an access point, identifies the transmission as a potentially interfering transmission, thereby interfering on the monitored channel. Configured to identify possible transmissions.

  In one embodiment, the memory is configured to store a list of clients associated with the access point, and the identification module may interfere with transmissions originating from transmitters that are not on the list of clients associated with the access point. Is configured to identify as a transmission.

  In one embodiment, the interference metric is the average signal strength of transmissions that may interfere on the monitored channel.

  In one embodiment, the interference metric is a moving average of the signal strength of transmissions that may interfere on the monitored channel.

  In one embodiment, the communication module is further configured to transmit an indication of an interference metric for the selected communication channel on the selected communication channel.

  FIG. 1 illustrates a wireless network according to one embodiment. The wireless network includes an access point (AP) 100 and five clients (STAs) 21, 22, 23, 24, 25. The client communicates wirelessly with the access point 100 via a wireless channel.

  FIG. 2 shows the AP 100 in more detail. The AP 100 includes a wireless network interface 110, a channel control module 120, a communication module 130, an identification module 140, a calculation module 150, and a memory 160. Wireless network interface 110 is coupled to antenna 115.

  The wireless network interface 110 is operable to send and receive signals using the antenna 115 on one or more of a plurality of radio frequency channels defined in the radio frequency spectrum. The channel control module 120 selects which radio frequency channel the wireless network interface 110 uses. The communication module 130 controls the wireless network interface 110 to send and receive signals according to a communication protocol, for example, to a client STA, as described above in connection with FIG.

  The identification module 140 monitors the signal received by the wireless network interface 110 and operates in the vicinity where the detected signal is from a client associated with the AP 100 or operates on the same channel as the AP 100. Determine if it is another communication related to another AP. These signals can be either signals transmitted by neighboring APs or signals transmitted by clients of neighboring APs. The calculation module 150 performs calculations on the data extracted by the identification module 140 from signals associated with other APs. The memory 160 stores data extracted from these signals.

  The method performed by the modules of AP 100 is described in further detail below.

  FIG. 3 illustrates a wireless communication method according to one embodiment. In step S302, the channel control module 120 causes the wireless network interface 110 to switch to a channel to be monitored, referred to as a monitored channel in the following description. In step S304, the identification module 140 identifies transmissions that may interfere on the monitored channel. The identification module 140 identifies transmissions that may interfere by comparing the identifier of the node on which the transmission occurred with a list of clients associated with the AP 100. If the node is not on the list of clients associated with AP 100, the transmission is identified as a potentially interfering transmission. A count of potentially interfering transmissions on the monitored channel is stored in memory 160. Each time the identification module 140 identifies a potentially interfering transmission, the count for the monitored channel is incremented.

  In step S306, the calculation module 150 calculates an interference metric regarding the monitored channel. The interference metric is a function of a count of potentially interfering transmissions observed on the monitored channel. In addition to maintaining a count of potentially interfering transmissions, the sum of observed signal strengths of potentially interfering transmissions is also stored by the identification module 140. The interference metric is a function of both the sum of the signal strengths and the count of transmissions that may interfere.

  In step S308, the interference metric calculated for the monitored channel is stored in the memory 160. In step S310, a check is performed regarding whether all channels have been monitored. If there are still channels to be monitored, the method returns to step S302 and a new channel is selected as the monitored channel. When all channels are monitored, the method proceeds to S312.

  In step S312, a communication channel is selected. The communication channel is selected by comparing the interference metrics stored in memory for each channel and selecting the channel with the lowest interference metric as the communication channel. In step S314, the AP 100 communicates with the client using the selected communication channel.

  An AP according to the above embodiment operating on a channel “i” may receive various transmissions on that channel. Some of these transmissions may be from clients connected to this AP, and some other transmissions are from neighboring APs operating in the vicinity on the same channel. Management frames (e.g. beacon) transmissions, some transmissions may be from nearby clients connected to neighboring APs operating on the same channel is there. In the case of transmission from a client associated with this AP, the frame is decoded and passed to an upper layer.

  For transmissions from other devices, such as other APs and clients connected to other APs, the signal strength recorded during frame reception is stored and the rest of the frame is discarded. Note that in some cases, only the header may be decodable and the frame may not be decodable. There are two possible causes for this. First, the client may be located physically away from the AP, and signal attenuation may affect reception quality. Second, in communications compliant with the IEEE 802.11 standard and other technical specifications, the frame header is always sent at the base rate, even if the rest of the frame is sent at a faster rate, Thereby, the header may be able to be decoded over a longer transmission distance than the rest of the frame.

  In the context of this disclosure, only frames with at least a decodable header are considered. When an AP intercepts a transmission from a client, the AP can compare the node on which this transmission occurred against a list of clients associated with it. If no match is found, this indicates an interception of the interference transmission. When intercepting such a transmission, the signal strength is recorded, the recorded value is added to the cumulative parameter, and the counter is incremented. At the same time, an interference metric is calculated. This can be a count of interfering transmissions experienced over a window, or some function calculated over the sum and count parameters. The reason for using the cumulative counter is that when many nodes in the neighboring cell are not active, the counter has a low value as well, while the nodes in the neighboring cell are actively transmitting. This is because the counter is likely to have a large value when it is within the wireless vicinity of the AP.

  In the above embodiment, the sum of the observed signal strengths is stored by the AP. In alternative embodiments, the average, maximum value, median or moving average is stored.

  FIG. 4 shows a start procedure at an access point according to one embodiment. In step S402, the access point is switched on. After the AP is turned on, in step S404, the AP tunes to the first non-overlapping channel. The AP remains in each channel for a period of time until the dwell timer expires. In step S406, the count, sum, and timerExpiredFlag values are set to zero. Thereafter, a dwell timer for the monitored channel is started. The AP then collects information on this channel and moves to the next channel when the dwell timer expires. In step S408, the AP determines whether a frame has been received. If no frame is received, the method proceeds to step S410, where the AP determines whether the dwell timer has expired. If the dwell timer has not expired, the method returns to step S408.

  If, in step S408, the AP determines that a frame has been received, the method proceeds to step S412. In step S412, the AP checks whether the received frame is associated with the AP client. If the received frame is associated with the AP client, the frame is processed in step S414 and the method returns to step S410. If the received frame is not associated with the client of the AP, the AP checks in step S416 if the received frame is an association request. If the received frame is an association request, it is processed in step S414 and the method returns to step S410. If the received frame is not an association request, the method proceeds to step S418.

  In step S418, an indication of the possibility of interference from the received frame is added to the total value and the counter is incremented. In this embodiment, the possible interference indication from the received frame is a received signal strength indicator (RSSI) for the received frame. In step S418, an interference metric is also calculated from the sum value and the count value. The interference metric is a function of the sum value and the count value. For example, the interference metric f (sum, count) can be the average signal strength of the interference transmission calculated by dividing the sum by the count.

  The interference metric can be a moving average, or the count value itself can be used as the interference metric.

  After step S418, the method proceeds to S410. As described above, in step S410, the AP determines whether the dwell timer has expired. If the dwell timer has expired, the method proceeds to step S420. In step S420, the sum, count, and interference metric values corresponding to the monitored channels are stored in the AP memory. After step S420, the method proceeds to step S422.

  In step S422, a check is performed to determine whether all channels have been scanned. If all channels have not been scanned, in step S424, the next unscanned channel is selected as the monitored channel, and the method returns to step S406 for the new monitored channel. If it is determined in step S422 that all channels have been monitored, the method proceeds to step S426. In step S426, the channel is selected as the communication channel. The interference metric values for each monitored channel are compared, and the channel with the lowest interference metric is selected as the communication channel. Thereafter, the AP switches to the channel selected as the communication channel and starts normal operation in this channel. Thereafter, the method proceeds to step S428 where protocol processing is performed. The protocol processing step S428 shown in FIG. 4 and the figures shown below indicates that the AP is communicating on the selected communication channel, or is idle during communication on the selected communication channel.

  As described above, the AP intercepts transmissions to capture the level of potential interference on each channel in the vicinity of its radio. The AP maintains statistics for each non-overlapping channel over a certain window. The window length can be equal to or greater than the dwell time on the channel. When the dwell time counter expires, the AP moves to the next channel and repeats the process. The process continues until the AP has scanned all non-overlapping channels. The purpose of doing this is to select an operating channel where the AP can minimize the level of potential interference.

  FIG. 5 shows data stored in the memory of the AP in one embodiment. Each AP can maintain a history list of one set <sum, count, interferenceMetric> as shown in FIG. The length of this history is an adjustable parameter “N”. This list can be implemented, for example, with a sliding buffer that overwrites the oldest value in the list whenever the list is full.

As shown in FIG. 5, the AP has N sets of statistics (stat _i1 , stat _i2 ,... Stat _iN ) for channel i and N sets of statistics (stat _j1 , stat _j2 ,... stat _jN ) and the corresponding set of statistics for each channel up to channel m. In each case, the statistics include sum, count and interference metric values.

  At the start of each new monitoring cycle, the parameters <sum, count, interferenceMetric> are all reset so that the measured values indicate the latest state in the vicinity of the radio. In addition, at the end of the monitoring cycle, any new statistics collected are stored in the history list corresponding to the monitored channel. By storing historical information about “N” latest monitoring cycles, the AP can identify trends that may be taken into account in the channel selection / switching process.

  In one embodiment, the AP can calculate the trend using time series prediction or a simple moving average. These trends are used to identify whether the likelihood of interference is increasing, decreasing, or remains constant. The AP can compare trends across different channels, and the trends can be included in the channel selection process. In one embodiment, the AP can use machine learning techniques to identify periodic trends, such as whether a particular channel has a high level of interference potential at a particular time.

  Assuming that the AP has a single wireless card, other channels will be temporarily monitored to keep up to date the potential interference information. This monitoring can be done periodically or when the AP is idle. A periodic monitoring process is shown in FIG. In one embodiment, the AP can perform such monitoring in a responsive manner. That is, the process shown in FIG. 6 is started when the AP undergoes performance degradation.

  FIG. 6 illustrates a channel scanning method according to one embodiment. In step S602, the AP determines that it is idle. In step S604, the AP temporarily switches to another channel as the monitored channel in order to update the information about the monitored channel.

  As described above in connection with FIG. 4, the AP then remains on the monitored channel for a period of time until the dwell timer expires. In step S606, the count, total, and timerExpiredFlag values are set to zero. Thereafter, a dwell timer for the monitored channel is started. The AP collects information about this channel and moves to the next channel when the dwell timer expires. In step S608, it is determined whether a frame has been received. If no frame has been received, the method proceeds to step S610 where it is determined whether the dwell timer has expired. If the dwell timer has not expired, the method returns to step S608.

  If it is determined in step S608 that a frame has been received, the method proceeds to step S612. Since an AP is monitoring a channel that it is not operating on, it can be assumed that any frames received are not associated with that AP and therefore may interfere.

  In step S612, an indication of the possibility of interference from the received frame is added to the total value, and the counter is incremented. As discussed above, the possible interference indication from the received frame is a received signal strength indicator (RSSI) for the received frame. In step S418, an interference metric is also calculated from the sum value and the count value. The interference metric is a function of the sum value and the count value.

  After step S612, the method proceeds to S610 where it is determined whether the dwell timer has expired. If the dwell timer has expired, the method proceeds to step S614. In step S614, the sum, count, and interference metric values corresponding to the monitored channels are stored in the AP memory. After step S614, the method proceeds to S616.

  In step S616, the values in the history list in the AP's memory for the monitoring channel are updated. Thereafter, the AP switches back to the operating channel and a different candidate channel is selected as the next monitored channel for which the AP performs a temporary scan. Thereafter, the method proceeds to step S618, where protocol processing is performed.

  Another approach to gathering neighbor information for other channels is to utilize information gathered by other neighboring APs operating in the neighborhood for these channels. Each AP (eg, AP1) is monitoring its neighborhood on its operating channel (channel X). AP 1 can then advertise this information (eg, sum, count, interference metric) on the operating channel (channel X) via a beacon frame. Whenever another AP (AP2) operating another channel (channel Y) temporarily tunes to channel X to monitor the state of this channel, both these APs are in range of each other. If so, the possibility of interference with channel X can be easily captured by listening to the beacon from AP1. Such an approach will give an approximate state of the neighborhood, but can significantly reduce the scan time. Therefore, such an approach will help to quickly estimate the likelihood of interference for the candidate channel.

  The information advertised by the AP can be the latest value of the interference metric. Alternatively, or in addition, the AP can advertise summary values that indicate a trend or periodic variation in the likelihood of interference for the operating communication channel.

  The AP may be experiencing an interference level that is being compared to the interference level, for example, when a scan of neighboring channels indicates the availability of a promising alternative channel compared to the operating channel, and when the operating channel is selected. One may choose to switch its operating channel under various circumstances, such as when it goes up (eg, when the retransmission rate is above a certain threshold). Each AP monitors dynamically and keeps up-to-date information about the different channels so that at any given time, the AP can select the channel that promises to provide the best performance. .

  FIG. 7 illustrates a method for switching channels in one embodiment. In step S702, protocol processing is performed by the AP that communicates on the selected communication channel. In step S704, it is determined whether channel switching has been triggered. An example of channel switching was discussed in the previous paragraph. If channel switching has not been triggered, the method returns to step S702. When channel switching is triggered, the stored values of interference metrics are compared and the channel with the lowest interference metric is selected as the new working channel. Thereafter, the AP switches to a new operation channel and returns to step S702.

  As discussed above, the interference metric used in the comparison to select a new working channel can be based on historical information about the monitored channel. Information in the history can be used to calculate summary values, or other probable alternative channels can be pointed out, for example, by identifying periodic variations or patterns of interference potential for the channel Can be used to determine insights. The summary for each channel can be compared to yield the best alternative channel at a given time.

  Another important issue to consider is to avoid synchronization between simultaneously operating neighbors, i.e. each neighbor, or neighbor pair. To alleviate this problem, randomization can be introduced. For example, instead of monitoring each channel sequentially, the channels can be randomly selected so that each AP scans each available channel at least once per cycle. In addition, randomization may be introduced during the channel switching process. In scenarios where two or more neighbors are on the same channel, it is desirable that the neighbors do not operate simultaneously. For example, it may not be desirable for two neighboring APs to switch channels at the same time, and both to switch to the same channel or interfering channels. To avoid such simultaneous switching, the AP can randomize its decision when facing a channel switching option. In one embodiment, the AP selects a random or pseudo-random number from a distribution and determines a sequence of actions if the random number is less than a threshold.

  8a in FIG. 8 shows a network neighborhood according to one embodiment. As shown in 8a of FIG. 8, the first AP1 has two clients n1 and n2. The second AP2 has three clients n6, n7 and n8. The third AP3 has three clients n3, n4 and n5.

  8b of FIG. 8 shows the communication intercepted by AP3 in the vicinity of the network shown in 8a of FIG. 8 during the channel scan. As shown in 8b of FIG. 8, the first AP1 intercepts frames transmitted by two of the clients n3 and n4 associated with the third AP3. Furthermore, the first AP1 also intercepts frames transmitted by the third AP3. Thus, during a channel scan according to one embodiment, the first AP1 determines the count of transmissions transmitted by the two clients n3 and n4 and the third AP3 and an indication of the strength of those transmissions. It will be. Thus, the first AP 1 will have an indication of the possibility of interference for the channel on which the third AP 3 is operating due to communication between the third AP 3 and its clients.

  As shown in 8b of FIG. 8, the second AP2 intercepts communication by one n6 of clients associated with the third AP3. Thus, during the channel scan, the second AP 2 will determine the sum of the transmission count and strength indication by the client n 5 of the third AP 3.

  Further, as shown in 8b of FIG. 8, the third AP3 transmits the transmission by the first AP1, the transmissions by the two clients n1 and n2 associated with the first AP1, and further the second AP2 The transmission by the client n6 is intercepted. Thus, if the first AP1 and the second AP were operating on the same channel, the third AP3 would determine a relatively high level of interference possibility on that channel during the scan. there is a possibility. If this is the case, the third AP 3 will then select an alternative channel either during startup or after a channel switch trigger.

  In the above embodiment, the access point comprises a single radio card or a wireless network interface. In an alternative embodiment, the access point comprises two wireless cards. FIG. 9 shows such an embodiment.

  FIG. 9 illustrates an access point according to one embodiment. The access point 900 includes a first wireless network interface 910, a second wireless network interface 970, a channel control module 920, a communication module 930, an identification module 940, a calculation module 950, and a memory 960. The first wireless network interface 910 is coupled to the first antenna 915 and the second wireless network interface 970 is coupled to the second antenna 975.

  Both the first wireless network interface 910 and the second wireless network interface 970 are operable to send and receive signals using the first antenna 915 and the second antenna 975, respectively. Each of the first wireless network interface 910 and the second wireless network interface 970 operates on one channel selected from a plurality of radio frequency channels. The channel control module 920 selects which radio frequency channel the first wireless network interface 910 uses and which radio frequency channel the second wireless network interface 970 uses.

  In this embodiment, the first wireless network interface 910 is used to communicate with a client associated with the access point 900 using one communication channel selected from a plurality of possible channels. The second wireless network interface 970 can be used simultaneously to scan other channels. The communication module 930 controls the first wireless network interface 910 to send and receive signals according to the communication protocol.

  The second wireless network interface 970 may be controlled by the channel control module 920 to operate on a different channel than the first wireless network interface 910. Accordingly, the second wireless network interface 970 can be used to perform a scan as shown in steps S604 to S616 in FIG. That is, the scan can be performed even when the AP 900 is not idle.

  In one embodiment, the identification module 940 monitors the signal received by the first wireless network interface 910 and the detected signal is a signal from a client associated with the AP 900 or another operating nearby. Determine if it is another communication related to the AP. The calculation module 950 performs calculations on the data extracted by the identification module 940 from signals associated with other APs. The memory 960 stores data extracted from these signals. As a result, in addition to the monitored channel, the AP 900 can collect information on interference related to the channel with which the AP 900 is communicating.

  Embodiments have the advantage that the AP can take into account the possibility of interfering transmissions on each channel and can select the channel with the least likelihood. Further, dynamically monitoring and maintaining history information can provide more useful information that may improve channel selection / switching decisions. Furthermore, embodiments may be implemented without requiring any modification other devices operating in the vicinity of the same network. Using the above method, the AP can depict the situation of neighboring channels and can select the channel that provides the lowest potential for interference.

  In an embodiment, a central controller is not required because each access point can make decisions independently in a distributed manner. Furthermore, in a scenario where a plurality of APs belonging to different management entities share a wireless proximity, the centralized management method may not be achieved. According to an embodiment, there may be an indeterminate wireless environment, particularly where there is no facility for an AP to initiate another AP change, and each AP attempts to select a path with the least interference if possible. The AP will be able to operate in a wireless environment where it can be attempted.

  Specific embodiments are presented schematically. The reader will understand that the detailed implementation of each embodiment may be achieved in several ways. For example, a dedicated hardware implementation can be designed and constructed. On the other hand, a processor may implement a management unit as described above in connection with an embodiment, by a storage medium (eg, a device based on magnetic, optical, solid state memory) or by a computer receivable signal (eg, a complete Downloadable program or “patch” update to an existing program). In addition to these two situations, multifunction hardware devices such as DSPs, FPGAs, etc. can be configured with configuration instructions.

  Although several embodiments have been described, these embodiments are presented by way of example only and are not intended to limit the scope of the invention. Indeed, the novel devices and methods described herein may be embodied in various other forms; further, as described herein without departing from the spirit of the invention. Various omissions, replacements and changes may be made to the device, method and product configurations. The appended claims and their equivalents are intended to include forms and modifications that will fall within the scope and spirit of the invention.

Claims (18)

A wireless communication method at an access point of a wireless network, wherein the access point comprises a wireless network interface configured to be switchable between a plurality of wireless communication channels.
Monitoring each of a plurality of monitored channels from the plurality of wireless communication channels over a period of time;
Configuring the wireless network interface to remain in the monitored channel for a period of time to monitor the monitored channel;
Identifying potentially interfering transmissions on the monitored channel and determining a count over the certain period of potentially interfering transmissions on the monitored channel;
Calculating an interference metric for the monitored channel based on at least the count of potentially interfering transmissions on the monitored channel;
Storing the interference metric for the monitored channel over the period of time when the period of time has elapsed;
Monitoring each of a plurality of monitored channels from the plurality of wireless communication channels over a period of time comprising:
Comparing the stored interference metrics for the plurality of monitored channels and selecting the monitored channel having the lowest interference metric as a communication channel;
Configuring the access point to communicate via the wireless network using the selected communication channel.   Monitoring each of the plurality of monitored channels over a period of time further comprises determining an indicator of received signal strength for each identified potentially interfering transmission on the monitored channel; Interference metrics are the count of potentially interfering transmissions on the monitored channel and the sum of indications of the indicator of the received signal strength for each potentially interfering transmission on the monitored channel. The method of claim 1, wherein the method is calculated based on.   Identifying potentially interfering transmissions on the monitored channel includes receiving a transmission, determining a destination of the received transmission, and when the destination is not the access point, 3. A method according to claim 1 or 2, comprising identifying the transmission as a transmission that may interfere.   4. The method of any one of claims 1-3, wherein communicating via the wireless network using the selected communication channel comprises communicating using the wireless network interface.   The access point includes a first wireless network interface and a second wireless network interface, each of which is configured to be switchable between the plurality of wireless communication channels, and each of the plurality of monitored channels is fixed. Monitoring over a period of time includes switching the first wireless network interface to a respective monitored channel from the plurality of monitored channels, and communicating via the wireless network using the selected communication channel. 5. The method of any one of claims 1-4, wherein doing includes switching the second wireless network interface to the selected communication channel.   6. A method as claimed in any preceding claim, wherein the interference metric is an average signal strength of the potentially interfering transmissions on the monitored channel.   The method according to claim 1, wherein the interference metric is a moving average of signal strength of the potentially interfering transmissions on the monitored channel.   8. The method of any one of claims 1 to 7, further comprising transmitting an indication of the interference metric for the selected communication channel on the selected communication channel.   A computer readable recording medium recording processor-executable instructions that, when executed on a processor, cause the processor to perform the method of any one of claims 1-8. An access point for a wireless network,
A first switch configured to switch between a plurality of wireless communication channels and to monitor each of the plurality of monitored channels from the plurality of wireless communication channels in order to remain in each monitored channel over a certain period of time; A wireless network interface;
Configured to identify potentially interfering transmissions on monitored channels of the plurality of wireless communication channels and to determine a count over the period of potentially interfering transmissions on the monitored channels An identification module;
A calculation module configured to calculate an interference metric for the monitored channel based on at least the count of potentially interfering transmissions on the monitored channel;
A memory configured to store the interference metric for each monitored channel over the period of time when the period of time has elapsed;
An access point comprising: a communication module configured to cause the access point to communicate over the wireless network using a communication channel selected by comparing the interference metrics stored in the memory.   The access point of claim 10, wherein the communication module is configured to communicate over the selected communication channel using the first wireless network interface.   12. An access according to claim 10 or 11, further comprising a second wireless network interface, wherein the communication module is configured to communicate over the selected communication channel using the second wireless network interface. point.   The identification module further determines a signal strength of the identified potentially interfering transmission on the monitored channel and determines a sum of the signal strength of the potentially interfered transmission on the monitored channel. Configured to determine, based on the count of potentially interfering transmissions and the sum of the signal strengths of the potentially interfering transmissions on the monitored channel, 13. An access point according to any one of claims 10 to 12, configured to calculate the interference metric for the monitored channel.   The identification module interferes on the monitored channel by determining the destination of the received transmission and identifying the transmission as a potentially interfering transmission when the destination is not the access point 14. An access point according to any one of claims 10 to 13, configured to identify potential transmissions.   The memory is configured to store a list of clients associated with the access point, and the identification module may interfere with transmissions originating from transmitters that are not on the list of clients associated with the access point. 14. An access point according to any one of claims 10 to 13, configured to identify as a transmission.   The access point according to any one of claims 10 to 15, wherein the interference metric is an average signal strength of the potentially interfering transmissions on the monitored channel.   16. The access point according to any one of claims 10 to 15, wherein the interference metric is a moving average of the signal strength that may interfere with the monitored channel.   18. The access according to any one of claims 10 to 17, wherein the communication module is further configured to transmit an indication of the interference metric for the selected communication channel over the selected communication channel. point.