METHOD AT A FIRST ACCESS POINT OR AT A SECOND ACCESS POINT TO DETECT INTERFERENCE, FIRST ACCESS POINT AND SECOND ACCESS POINT CONFIGURED TO DETECT INTERFERENCE, SYSTEM FOR DETECTING INTERFERENCE AND STORAGE MEDIA

Abstract

METHOD, DEVICE AND INTERFERENCE DETECTION SYSTEM. A method for detecting interference in wireless networks is disclosed. A leading idea is to use a first access point to detect interference disturbing a wireless device associated with a second access point, where the device at the source of the interference is in range of the first access point but not in range of the second access point. second access point. Taking advantage of the difference in coverage between different wireless network technologies, the first access point is able to detect data traffic from a second access point and a short-range jamming device on the same frequency channel. More precisely, by measuring a strength level of a received signal on the frequency channel in a period of time when no data traffic from the second access point is detected, the first access point is able to detect interference according to the measured signal. The interference detected corresponds to another device using the second access point's frequency channel, not communicating with the second access point. Since interference detected by the first access point may not be detected by the second access point (because it is not in range of the second access point, although it does disturb some of its associated devices), the first access point advantageously sends an item information indicating that interference was detected. Sending this indication is advantageous as it allows the second access point to detect an interfering device, even if it is not in range.

Description

1 / 25 “METHOD AT A FIRST ACCESS POINT OR AT A SECOND ACCESS POINT TO DETECT INTERFERENCE, FIRST ACCESS POINT AND SECOND ACCESS POINT CONFIGURED FOR "DETECTING INTERFERENCE, SYSTEM FOR DETECTING INTERFERENCE AND STORAGE MEDIA" 1. TECHNICAL FIELD

[001] The technical field of the method, device and system described is related to wireless networks, wireless access points and interference detection in radio frequency channels. 2. BACKGROUND OF THE ART

[002] Wireless networks using unlicensed bands are very popular and used in many places. Wi-Fi represents a widely adopted technology worldwide that operates in the unlicensed 2.4 GHz and / or 5 GHz bands. As Wi-Fi is widely adopted, unlicensed bands become crowded, and access points have to mitigate interference through appropriate channel allocation techniques. Furthermore, since unlicensed bands are inherently open to different types of network protocols, devices operating in these bands must deal with various types of interference. The 2.4 GHz wireless band is, for example, used by microwave ovens, Bluetooth devices, cordless phones, baby monitors, and IEEE 802.15.4 devices, also known as ZigBee devices. Some methods are known to mitigate interference problems, such as dynamic channel allocation methods implemented by access points.Dynamic channel allocation methods typically involve an access point that scans the frequency band, measuring received signal strength across multiple frequency channels and searching for a frequency channel with a reasonably low level of activity. Since an access point is not located in the same place as its associated devices, there may be... Petition 870250052526, dated 06 / 23 / 2025, page 7 / 66 2 / 25 situations where an associated device is locally disrupted by another interfering wireless device that is not within range of the access point. In this situation, even if the access point detects a degradation in transmission performance with an associated device, the access point has no technical means to diagnose and correct the problem. Because the interfering device is not within range of the access point, there is no way for the access point to determine the source of the problem. Such performance degradations are frequent reasons for a perceived malfunction of a Wi-Fi network by a user who may dismiss the fault as being in their Wi-Fi gateway.

[003] Furthermore, with the rapid growth of smart home solutions based on IEEE 802.15.4, also known as ZigBee, which has less coverage than Wi-Fi and sixteen channels that overlap with Wi-Fi channels, such situations are occurring more and more frequently. A solution is needed to enable an access point to detect interference occurring in a remote location and disrupting some of its associated wireless devices. 3. SUMMARY OF THE INVENTION

[004] A key idea is to use a first access point to detect interference disrupting a wireless device associated with a second access point, where the device causing the interference is within the range of the first access point but not within the range of the second access point. By leveraging the coverage difference between different wireless network technologies, the first access point is able to detect data traffic from a second access point and a short-range interfering device on the same frequency channel. More precisely, by measuring the strength level of a received signal on the frequency channel during a period when no data traffic from the second access point is detected, the first access point is able to detect interference based on the measured signal. The detected interference Petition 870250052526, dated 06 / 23 / 2025, page 8 / 66 3 / 25 corresponds to another device using the frequency channel of the second access point, without communicating with the second access point. Since the interference detected by the first access point may not be detected by the second access point (because it is not within the second access point's range, although it disturbs some of its associated devices), the first access point advantageously sends an information item indicating that interference has been detected. Sending this indication is advantageous because it allows the second access point to detect an interfering device, even if it is not within its range.

[005] To this end, a method is disclosed at a first access point for detecting interference. The method comprises: - detect data traffic from a second access point on a frequency channel; - Obtain a signal strength level from a received signal on the frequency channel during a period when no data traffic is detected; - sending an information item indicating that interference was detected on the frequency channel according to the level obtained.

[006] According to a particularly advantageous variant, the sending of the information item comprises the transmission of the information item on the frequency channel.

[007] According to another particularly advantageous variant, sending the information item includes transmitting the information.

[008] According to another particularly advantageous variant, the sending of the information item comprises a unicast transmission of the information item to the second access point.

[009] According to another particularly advantageous variant, the first access point and the second access point are Wi-Fi access points.

[010] According to another particularly advantageous variant, obtaining the Petition 870250052526, dated 06 / 23 / 2025, page 9 / 66 4 / 25 signal strength level involves performing a clean channel assessment of the frequency channel.

[011] According to another particularly advantageous variant, the first access point also comprises another wireless interface according to a ZigBee or Bluetooth type protocol.

[012] According to another particularly advantageous variant, the information item also includes an indication of the type of protocol that created the interference.

[013] According to another particularly advantageous variant, the information item also includes a value that quantifies the detected interference.

[014] In a second aspect, a method is also disclosed at a second access point for detecting interference. The method comprises: - sending and receiving data on a frequency channel, - to receive from a first access point an item of information indicating that interference has been detected based on a signal strength level obtained by the first access point on the frequency channel during a period when no data is being sent or received by the second access point.

[015] According to another particularly advantageous variant, the method further comprises switching the second access point to a second frequency channel to measure another resistance level of another signal received on the second frequency channel.

[016] In a third aspect, a first access point device configured to detect interference is also revealed. It comprises: - means to detect data traffic from a second access point on a frequency channel; - methods for obtaining a signal strength level from a received signal on a frequency channel during a period when data traffic is not detected; Petition 870250052526, dated 06 / 23 / 2025, page 10 / 66 5 / 25 The means to send an information item indicating the interference were detected on the frequency channel according to the level obtained.

[017] In a fourth aspect, a first access point device configured to detect interference is also revealed. It comprises a processor configured to: - detect data traffic from a second access point on a frequency channel; - Obtain a signal strength level from a received signal on the frequency channel during a period when no data traffic is detected; - Send an information item indicating that interference was detected on the frequency channel according to the level obtained.

[018] In a fifth aspect, a second access point device configured to detect interference is also revealed. This comprises: - means for sending and receiving data on a frequency channel, - means to receive from a first access point an item of information indicating that interference has been detected, based on a signal strength level obtained by the first access point on the frequency channel during a period when no data is sent or received by the second access point.

[019] In a sixth aspect, a second access point device configured to detect interference is also revealed. It comprises a processor configured to: - sending and receiving data on a frequency channel, - to receive from a first access point an information item indicating that interference was detected according to a signal strength level obtained by the first access point on the frequency channel during a period in which no data is sent or received by the second access point.

[020] In a seventh aspect, a system for detecting is also disclosed. Petition 870250052526, dated 06 / 23 / 2025, page 11 / 66 6 / 25 an interference. The system comprises a first access point and a second access point, where: - The second access point is configured to process data traffic on a frequency channel; The first access point is configured for: Detect data traffic from the second access point on the frequency channel; To obtain a signal strength level from a received signal on the frequency channel during a period when no data traffic is detected; Send an information item to the second access point to indicate that interference was detected on the frequency channel according to the level obtained.

[021] In an eighth aspect, a computer program for detecting interference is also disclosed. The computer program comprises program code instructions executable by a processor to execute the method implemented at the first access point in any of its variants, or the method implemented at the second access point in any of its variants.

[022] In a ninth aspect, a computer-readable storage medium is also disclosed that stores program instructions executable by the computer. The computer-readable storage medium comprises program code instructions executable by at least one processor to execute the method implemented at the first access point in any of its variants, or the method implemented at the second access point in any of its variants.

[023] Although not explicitly described, the present embodiments may be employed in any combination or subcombination. By Petition 870250052526, dated 06 / 23 / 2025, page 12 / 66 7 / 25 For example, the present principles are not limited to the variants described, and any arrangement of variants and embodiments may be used. Furthermore, the present principles are not limited to the examples described of ZigBee or Bluetooth, and any other type of interfering technology is compatible with the disclosed principles. The present principles are not limited to the unlicensed 2.4 GHz and / or 5 GHz unregistered bands and are applicable to any other licensed or unlicensed band. The present principles are no longer limited to the wireless technologies described.

[024] Furthermore, any feature, variant or embodiment described for a method is compatible with an access point device intended to process the described method, with a computer program product comprising program code instructions and with a computer-readable storage medium storing program instructions. 4. BRIEF DESCRIPTION OF THE DRAWINGS

[025] In the drawings, one embodiment of the present description is illustrated. As follows: Figure 1 represents an example of an interference situation occurring according to a specific, non-limiting concretization; Figure 2a illustrates a method for detecting interference according to a specific and non-limiting embodiment; Figure 2b illustrates the method for detecting interference according to another specific and non-limiting embodiment; Figure 3 represents a processing device for detecting interference according to two specific and non-limiting embodiments; Figure 4 represents an exemplary architecture of the processing device in Figure 3 according to a specific, non-limiting embodiment. 5. DESCRIPTION OF THE METHODS OF IMPLEMENTATION

[026] Figure 1 illustrates an example of an interference situation. Petition 870250052526, dated 06 / 23 / 2025, page 13 / 66 8 / 25 occurring according to a specific and non-limiting embodiment of the principles described. A first access point AP1 is installed in a first house 10 of a first user. The first access point AP1 comprises a wireless network interface operating on a radio frequency channel ch3. According to the specific and non-limiting embodiment of the principles described, the first access point AP1 provides wireless network functions for wireless stations STA3 also operating on the radio frequency channel ch3. According to the specific and non-limiting embodiment of the principles described, a second access point AP2 is installed in a second house 20 of a second user, the second house 20 being a neighboring house to the first house 10.The second wireless access point AP2 also comprises a wireless network interface, operating on a different radio frequency channel ch2 to provide wireless networking functions towards other wireless stations STA2, STA3 also operating on the other radio frequency channel ch2. According to the illustrated example, operating on two different radio frequency channels ch2, ch3, the first and second access points AP1, AP2, although neighboring access points do not interfere with each other.

[027] For reasons of clarity and without loss of generality, the wireless network provided by the first and second access points AP1, AP2 is referred to throughout the description as a Wi-Fi network operating in the unlicensed 2.4 GHz band, according to any IEEE 802.11 variant, but any other type of wireless network operating in any other band is also applicable to the disclosed principles.

[028] Throughout the document, the strength level is described as being measured by RF's front extremities.

[029] For clarity and without loss of generality, the first and second access points are described as having local RF front ends to measure a signal strength level. This is also applicable to access points with non-local RF front ends, such as, for example, virtualized access points, Petition 870250052526, dated 06 / 23 / 2025, page 14 / 66 9 / 25 where an RF front end is located a few kilometers away from a radio equipment controller (performing baseband processing for the access point). The radio equipment controller is connected to the RF front end via a fiber optic cable.

[030] According to a specific and non-limiting embodiment of the principles described, the first access point AP1 further comprises another optional wireless interface, which also operates in the 2.4 GHz band. This other optional wireless interface is, for example, a ZigBee interface according to the IEEE 802.15.4 standard for wireless connection, for example, a ZigBee controller ZB1 for the first access point AP1. The ZigBee controller ZB1 is further wirelessly connected to another ZigBee device ZB2, for example, a ZigBee sensor using an IEEE 802.15.4 ultra-low power protocol. In one variant, the ZigBee devices ZB1, ZB2 constitute an autonomous wireless network independent of the first AP1 or second access point AP2. This is the case, for example, when the first access point AP1 does not include a ZigBee-compatible wireless interface.Any other type of wireless interface also operating in the 2.4 GHz band, such as Bluetooth for wireless connection of additional peripherals to the first access point AP1, or between them independently of the first access point AP1, is also compatible with the disclosed principles.

[031] The 2.4 GHz unlicensed band is further illustrated in Figure 1 from an IEEE 802.11 perspective as a set of three consecutive frequency channels ch1, ch2, ch3. Each frequency channel ch1, ch2, ch3 has a bandwidth of 22 MHz and a distance of 25 MHz separates the centers of two consecutive IEEE 802.11 frequency channels. Figure 1 further illustrates the unlicensed 2.4 GHz band from an IEEE 802.15.4 perspective as a set of sixteen consecutive frequency channels z11, z12, z13, z14, z15, z16, z17, z18, z19, z20, z21, z17, z18, z19, z20, z21, z22, z23, z34, z25, z26, overlapping the three channels of Petition 870250052526, dated 06 / 23 / 2025, p. 15 / 66 The IEEE 802.11 frequency channels z11-z26 have a bandwidth of 3 MHz, and a distance of 5 MHz separates the centers of two consecutive IEEE 802.15.4 frequency channels. Figure 1 further illustrates how the IEEE 802.11 frequency channels overlap with the IEEE 802.15.4 frequency channels, vertically representing the overlapping channels of both protocols. For example, the second IEEE 802.11 frequency channel z11 overlaps the four consecutive IEEE 802.15.4 frequency channels z16, z17, z18, z19. Furthermore, the frequency band is represented twice, the left side corresponding to the frequency band usage as perceived by the first access point AP1, and the right side corresponding to the frequency band usage as perceived by the second access point AP2.

[032] As described earlier, some interfering wireless technologies, such as ZigBee or Bluetooth, have a fairly limited range. In the example illustrated in Figure 1, the ZigBee controller ZB1 and / or the ZigBee sensor ZB2 interfere with the wireless station STA2, although they are not within range of the second access point AP2. The ZigBee devices ZB1, ZB2 use the Z18 channel of the ZigBee frequency which overlaps with the WiFi frequency channel ch2 used by the wireless stations STA2. As ZigBee devices are installed in house 10, they are configured to use a ZigBee channel z18 that does not interfere with the frequency channel ch3 of the first access point AP1 in house 10. This can be done automatically by ZigBee devices ZB1, ZB2 that detect a power level on the frequency channel ch3, or more manually by a user who does not select overlapping frequencies for the Wi-Fi and ZigBee wireless networks in house 10.The second access point in the neighboring house 20, being located far enough away from the ZigBee devices ZB1, ZB2 to detect them, has no way of detecting that the frequency channel ch2 is polluted by the remote devices ZB1, ZB2 using channel z18 interfering with one of their associated stations STA2. Petition 870250052526, dated 06 / 23 / 2025, page 16 / 66 11 / 25

[033] Figure 2a illustrates a method for detecting interference according to a specific and non-limiting embodiment of the principles described. According to the specific and non-limiting embodiment of the principles described, the method is performed on a first wireless access point AP1 comprising a wireless network interface operating on a radio frequency channel ch3. Detecting data traffic from the second access point AP2

[034] In step S20, the first access point AP1, operating a first wireless network on a first frequency channel ch3, is detecting data traffic from a second access point AP2 on a second frequency channel ch2. For example, the wireless network interface of the first access point AP1 comprises multiple RF (radio frequency) front ends capable of operating on multiple frequency channels in parallel during the same period of time. More precisely, each RF front end operates on a specific, possibly different, frequency channel, allowing the first access point to utilize the first wireless network on the first frequency channel ch3 with one front end and to scan other frequency channels ch1, ch2 to detect traffic or measure a received signal strength with another RF front end.In a second example, the wireless network interface of the first access point comprises a single RF front end capable of time-switching. More precisely, the RF front end is capable of sequentially switching and using different frequency channels ch1, ch2, ch3. In other words, the RF front end operates a first wireless network on the first frequency channel ch3 for a period of time, then switches to a second frequency channel ch2 to detect traffic or measure a received signal strength, for another period of time, and so on.

[035] Without loss of generality, the data traffic of the second access point AP2 is defined as comprising any data or control packet received and / or transmitted by the second access point AP2. For example, the traffic Petition 870250052526, dated 06 / 23 / 2025, page 17 / 66 12 / 25 data traffic from the second access point AP2 comprises any packet transmitted by the second access point AP2 to a STA2 or STA3 station. Data traffic from the second access point AP2 also includes any unicast, multicast, or broadcast packet transmitted by the second access point AP2. Data traffic from the second access point AP2 also includes any packet sent by a STA2 or STA3 station to the second access point AP2. Depending on the configuration, the first access point AP1 may not be within range of the second access point AP2 and may not be able to detect packets sent by the second access point. The first access point AP1 may, however, detect packets transmitted by a STA2 station towards the second access point AP2.These detected packets belong to the detected traffic from the second access point AP2, even though the second access point AP2 is not within the range of the first access point AP1.

[036] Traffic detection from the second access point AP2 on the second frequency channel ch2 comprises configuring one of the RF front ends of the first access point AP1 to the second frequency channel ch2 in any of the variants described above. In a first variant, traffic detection from the second access point AP2 further comprises configuring the wireless interface of the first access point AP1 in a snoop mode in order to capture all data and control packets being transmitted by any wireless device within range of the first access point AP1 on the second frequency channel ch2. The captured packets are analyzed in order to extract network identifiers identifying the network devices, whether a station or an access point, and whether a source or destination of the captured packet.For clarity and without loss of generality, the MAC (Medium Access Control) address is used in the description for this network identifier, but any other type of network identifier, whether a network address or a connection identifier, may also be used. Petition 870250052526, dated 06 / 23 / 2025, page 18 / 66 13 / 25 logic is compatible with the disclosed principles. Captured packets are, for example, classified according to the network devices that sent and / or received them. The detected data traffic from the second access point AP2 comprises captured packets that were sent or received by the second access point AP2, where the MAC address of the second access point AP2 is in the source MAC address or destination MAC address field of the captured packets. The detected data traffic from the second access point AP2 also comprises the various beacons generated in transmission mode by the second access point AP2. The BSSID (Basic Service Set Identifier) ​​of the second access point AP2, identifying the second access point AP2 among other access points, is additionally used, in addition to the MAC address of the second access point AP2, to associate captured packets with the traffic of the second access point AP2.

[037] In a second variant, the detection of traffic from the second access point AP2 involves configuring the wireless interface to capture data packets according to a set of forwarding rules, so as to, for example, reduce the load of packets captured at the first access point AP1. Several techniques are available to experts in the art to configure a network interface to capture packet streams according to forwarding rules, for example based on IPtables or OpenFlow open software. The forwarding rules are, for example, determined to capture the data according to the transmission mode (single-cast / broadcast), or according to the source and / or destination MAC addresses. In a first example, the MAC address and / or BSSID of the second access point AP2 are pre-configured in the first access point AP1.In a second example, the MAC address and / or BSSID of the second access point AP2 are autonomously determined by the first access point, having performed a preliminary acquisition of data traffic in a snoop mode to detect devices in the vicinity. In a third example, the... Petition 870250052526, dated 06 / 23 / 2025, page 19 / 66 The MAC address and / or BSSID of the second access point AP2 (14 / 25) is configured on the first access point AP1 by a network management system that manages, for example, a set of access points, including the first and second access points AP1 and AP2.

[038] In an advantageous variant, the first access point AP1 is detecting a plurality of data traffic from a plurality of access points, each access point operating on the second frequency channel or on another frequency channel. Measuring the strength level of a received signal

[039] In step S22, a signal strength level is measured by the first access point AP1 where the signal is received on the frequency channel ch2 during a time period when data traffic from the second access point is not detected. For clarity and without loss of generality, the principles described are described with access points measuring a signal level with local embedded RF front ends, although they are equally applicable to access points obtaining a signal strength level possibly measured by an external and possibly remote RF front end.The principles disclosed are, for example, also applicable to virtualized access points where an RF front end (generally called radio equipment) is located a few kilometers away from a radio equipment controller (performing the baseband processing of the access point), both interconnected by an optical fiber carrying a baseband radio signal. Throughout the description, the term measured or measurement is not restricted to local measurement on a single device, but possibly means obtaining from another measuring device such as, for example, an external RF front end.

[040] The first access point AP1, for example, associates a time reference with any amount of energy detected, the time reference that Petition 870250052526, dated 06 / 23 / 2025, page 20 / 66 15 / 25 represents a time value when energy is detected or the corresponding signal is received. Some detected energy amounts still correspond to some data traffic from the second access point AP2 (in any of the variants described above), while some other detected energy amounts do not correspond to any data traffic from the second access point AP2. The detection of an energy amount on the frequency channel ch2 that does not correspond to any data traffic from the second access point AP2 is done, for example, by analyzing the time reference of each detected energy amount and which access point or device it corresponds to. They may correspond to Wi-Fi traffic received or directed to other access points; they may also correspond to radio frequency activity from any other device.In other words, a received signal corresponds to possible interference for the second access point AP2, when it is measured on the same frequency channel ch2 as the operating frequency of the second access point AP1, without being transmitted or directed to the second access point AP2. Trigger by sending an information item indicating a detection of interference.

[041] In step S24, the first access point AP1 sends an information item indicating that interference was detected on the second frequency channel ch2 according to the measured level.

[042] In a first variant, the first access point AP1 triggers the transmission of the information item if the measured level is above a certain energy value. In a first example, the given energy value corresponds to a ratio, for example, one-third of the maximum permitted power in the frequency band. In a second example, the given energy value corresponds to 20 dB above the minimum sensitivity of the receiver's physical layer. Any other definition of a given energy value is compatible with the Petition 870250052526, dated 06 / 23 / 2025, page 21 / 66 16 / 25 principles disclosed.

[043] In a second variant, the first access point AP1 triggers the transmission of the information item if the measured level is above a certain energy value for a minimum period of time.

[044] In a third variant, the first access point AP1 triggers the transmission of the information item if the measured level is above a certain energy value for a minimum fraction of a time period. The first, second, and third variants are only exemplary techniques that can be further combined to limit the amount of energy detected to trigger the transmission of the information item, indicating that interference has been detected on the second frequency channel ch2. Transmit the information item.

[045] Several variants are described below for the transmission of the information item by the first access point AP1. According to one variant, the first and second access points AP1, AP2 are connected to the same distribution system, for example, an Ethernet network, and the information item is transmitted by the first access point AP1 in the distribution system. According to another variant, the first access point AP1 sends the information item through a wireless network interface on the second frequency channel ch2. According to yet another variant, the information item is sent in transmission mode, wirelessly on the second frequency channel ch2, or using the distribution system described above.According to yet another variant, the information item is sent in single-cast mode by the first access point AP1, using the MAC address of the second access point AP2 as a destination MAC address for wireless transmission of the information item on the second frequency channel ch2, or using the distribution system previously described. According to yet another variant, the first access point AP1 is configured and managed by... Petition 870250052526, dated 06 / 23 / 2025, page 22 / 66 17 / 25 a network manager, using a remote management protocol, and the information item is transmitted to the network manager via the remote management protocol. According to this variant, the network manager will then communicate with the second access point AP2 to mitigate the detected interference. Indicating the detected interferences

[046] Several options are described below as possible variants for the content of the information item. In a first variant, the information item comprises an interference value that quantifies the detected interference. For example, the interference value represents a fraction of a time period (expressed as a percentage) for which a signal level, measured at step S22, is evaluated above the given power value. In another example, the signal level measured at step S22 is compared to a plurality of given power values, and the interference value represents a plurality of fractions of a period where each fraction corresponds to the signal measured at step S22, evaluated at a range of given power values. In a second variant, the information item further comprises an indication of the type of protocol that created the interference. The indication, for example, indicates whether the interfering protocol is ZigBee, Bluetooth, or unknown.The protocol type detection is, for example, performed by the first access point AP1, detecting the interfering protocol from a compatible wireless interface. Using a clean channel assessment (CCA)

[047] According to a specific and non-limiting embodiment of the principles described, the measurement of the signal strength level comprises performing a Clear Channel Assessment (CCA) of the second frequency channel ch2. CCA is defined in the IEEE 802.11-2007 standards as part of the physical layer. CCA involves two related functions: CCA-CS (Clear Channel Assessment - Carrier Sense) and CCA-ED (Clear Channel Assessment - Energy Detection). CCA-CS comprises the detection and decoding of Wi-Fi preambulars, and the protocol header of Petition 870250052526, dated 06 / 23 / 2025, page 23 / 66 18 / 25 Physical layer convergence, inferring the duration of time (in μs) for which the medium will be occupied. CCA-ED comprises the detection of non-Wi-Fi energy in the frequency channel and the transmission of data back. The ED threshold is, for example, defined as being 20dB above the minimum sensitivity of the physical layer receiver. According to this specific and non-limiting embodiment, the measured resistance level of the received signal during a period in which data traffic from the second access point AP2 is not detected, comprises non-Wi-Fi energy detected by CCA-ED and Wi-Fi energy detected by CCA-CS, excluding the detected traffic from the second access point AP2.

[048] If CCA is used, any of the variants described above for triggering the transmission of the information item, based on the measured strength level and measured signal duration, is applicable to the disclosed principles. In addition, any of the information item content variants described above based on the measured strength level and measured signal duration is applicable to the disclosed principles using CCA.

[049] Figure 2b illustrates the method for detecting interference according to another specific and non-limiting embodiment of the principles described. According to the specific and non-limiting embodiment of the principles described, the method is performed on a second wireless access point AP2 comprising a wireless interface operating a wireless network on a second frequency channel ch2.

[050] In stage S25, the second access point AP2 transmits and receives packets on the second frequency channels ch2. The transmission comprises broadcast, multicast and unicast data transmission on the second frequency channel ch2.

[051] In step S27, the second access point AP2 receives an information item from the first access point AP1 according to any variant described previously. The information item indicates that interference has been detected from Petition 870250052526, dated 06 / 23 / 2025, page 24 / 66 19 / 25 according to a signal strength level measured by the first access point AP1 on the second frequency channel ch2 during a period of time when no data was sent or received by the second access point AP2. As mentioned earlier, receiving such an indication that interference was detected on the same frequency channel by the first access point AP1 at points in time when no packets were sent or received by the second access point AP2 is advantageous because it allows the second access point AP2 to know about interference that it does not directly measure, but which may disturb some of its associated STA2 wireless devices. Once this indication is received, the second access point AP2 has a large set of possible actions to improve the situation.In one example, as an optional S29 step, the second access point AP2 switches to another frequency channel to measure the strength of another signal received on that channel, in order to determine if the other frequency channel provides better RF conditions than the currently used second frequency channel ch2. In another example, the second access point AP2 increases the transmission power to the associated stations. In yet another example, the second access point AP2 displays information through a user interface, indicating detected interference and suggesting that users move the second access point to improve RF conditions. In yet another example, the second access point AP2 is capable of forming multiple beams and alters the beam configurations, seeking to improve RF conditions.Any method for modifying the wireless interface configuration to improve RF conditions is compatible with the disclosed principles.

[052] According to yet another embodiment of the principles described, a system is revealed. The system comprises a first and a second access point AP1, AP2. The first access point AP1 sends and receives data on a first frequency channel ch3. The second access point AP2 sends and receives Petition 870250052526, dated 06 / 23 / 2025, page 25 / 66 20 / 25 data on a second frequency channel ch2. The first access point AP1 detects data traffic from the second access point AP2 on the second frequency channel ch2. The first access point AP1 also measures the signal strength level of a received signal on the second frequency channel ch2 during a period when data traffic from the second access point AP2 is not detected by the first access point AP1. The first access point AP1 detects some energy on the second frequency channel ch2, which does not correspond to any data traffic from the second access point AP2. There is a possibility that the detected energy interferes with some of the stations on the second access point AP2. Furthermore, it is possible that the second access point AP2 does not detect this energy due to different intervals and locations.Therefore, it is advantageous for the first access point AP1 to send an information item indicating that a quantity of energy was detected on the second frequency channel ch2 during time periods that do not correspond to any data traffic from the second access point AP2. The second access point AP2, for example, experiencing some transmission errors with one of its stations, despite a reasonable signal-to-noise ratio, and receiving the information item sent by the first access point AP1, is in a position to correlate the transmission errors with a possible remote interference device, which is not within its own reach. The second access point AP2, being aware of remote interference on the second frequency channel ch2, possibly affecting some of its associated wireless devices, can take any appropriate action to improve network conditions.

[053] The disclosed principles are advantageous in many situations. A prime example is an internet service provider that provides access points to customers in accordance with the disclosed principles. In dense urban areas, the internet service provider, by remotely managing and configuring its access points, has the ability to detect interference from a first point of view. Petition 870250052526, dated 06 / 23 / 2025, page 26 / 66 21 / 25 access, where interference disrupts some devices associated with a second access point, even though it is not directly detectable by the second access point. The Internet service provider advantageously adapts the configuration of the second access point to better mitigate the interference experienced by some of its associated devices.

[054] In a second example, a device manufacturer may advantageously implement the disclosed principles in its access points, so that its access points cooperate and work better in a closed neighborhood than a heterogeneous set of access points provided by different manufacturers not implementing the disclosed principles.

[055] Figure 3 represents a processing device for detecting interference, according to two specific and non-limiting embodiments of the principles described. The processing device 3 comprises a first network interface 30 configured to send and receive packets to / from at least one wireless device. According to different embodiments of the principles described, the first network interface 30 is a wireless network interface belonging to a set comprising: IEEE 802.11, which includes any variation of the IEEE 802.11 standard; Bluetooth in any of its variants.

[056] The processing device 3 further comprises a second optional interface 32 configured to send and receive packets to / from at least one other wireless device. According to different embodiments of the principles described, the second network interface 32 is a wireless network interface belonging to a set comprising: IEEE 802.15.3 in any of its variants, especially supporting ZigBee devices. Bluetooth in any of its variants. Petition 870250052526, dated 06 / 23 / 2025, page 27 / 66 22 / 25

[057] Generally, any wireless network interface that allows sending and receiving packets to / from a wireless device is compatible with the disclosed principles.

[058] According to a specific and non-limiting embodiment, the processing device 3 further comprises an optional third network interface 38 configured to send and receive packets to other devices. According to different embodiments of the principles described, the third network interface 38 belongs to a set comprising: - A wired local area network interface, such as Ethernet, MoCA, or a power line interface; - A bus interface such as USB in any of its variants; - A broadband network interface, which includes a wide area network interface such as xDSL, HFC, FTTx, WiMAX. - A wireless network interface in any of the variants mentioned above.

[059] The processing device 3 may, for example, comprise two third network interfaces 38, one being a wired LAN interface and one being a WAN interface, such as home gateways that provide internet access at home. More generally, any network interface that allows sending and receiving packets to other devices is compatible with the disclosed principles. The first, second and third interfaces 30, 32, 38 are connected to a processing module 34, which is configured to detect interference.

[060] According to a first non-limiting embodiment of the principles described, the first network interface 30 is configured to capture data packets on a radio frequency channel. The processing module 34 is configured to detect data traffic from an access point from the packets of Petition 870250052526, dated 06 / 23 / 2025, page 28 / 66 23 / 25 data captured by the first network interface 30. The processing module 34 is further instructed to configure the first network interface 30 to measure the strength level of a received signal on the frequency channel during a period when no data traffic is detected. The processing module 34 is further configured to send an information item indicating that interference was detected on the frequency channel according to the measured level. Depending on the variant, the information item is sent on any of the first 30, second 32, or third 38 network interfaces. This first embodiment of the processing device 3 corresponds to the first access point AP1 of the method described in Figure 2a.

[061] According to a second, non-limiting embodiment of the principles described, the first network interface 30 is configured to transmit and receive packets from a radio frequency channel. The processing module 34 is configured to process an information item indicating that interference has been detected according to a signal strength level measured by an access point on the frequency channel during a period when no data is sent or received by the processing device 3. According to different variants, the information item is received from either the first 30, second 32, or third 38 network interface. This second embodiment of the processing device 3 corresponds to the second access point AP2 of the method described in Figure 2b.

[062] Figure 4 represents an exemplary architecture of processing device 3 according to a specific and non-limiting embodiment, in which processing device 3 is configured to detect interference. Processing device 3 comprises one or more processor(s) 410, which is (are), for example, a CPU, a GPU and / or a DSP (digital signal processor), together with internal memory 420 (e.g., RAM, ROM, EPROM). Processing device 3 comprises a Petition 870250052526, dated 06 / 23 / 2025, page 29 / 66 24 / 25 or several Input / Output interface(s) 430 adapted to send, to display output information and / or allow a user to enter commands and / or data (e.g., a keyboard, a mouse, a touchpad, a webcam, a display screen), and / or to send / receive data through a network interface; and a power source 440 that may be external to the processing device 3.

[063] According to an exemplary and non-limiting embodiment, the processing device 3 further comprises a computer program stored in memory 420. The computer program comprises instructions which, when executed by the processing device 3, in particular by the processor 410, cause the processing device 3 to perform the processing method described with reference to Figures 2a or 2b. According to a variant, the computer program is stored externally to the processing device 3 on a non-transient digital data carrier, and on an external storage medium, such as an SD card, HDD, CD-ROM, DVD, a DVD read / write drive and / or a DVD read / write drive, all known in the technical field. The processing device 3 thus comprises an interface for reading the computer program.In addition, processing device 3 could access one or more Universal Serial Bus (USB) type storage devices (e.g., memory sticks) via corresponding USB ports (not shown).

[064] According to exemplary and non-limiting embodiments, processing device 3 is a device belonging to a set comprising: - an access point device; - an internet gateway device; - a set-top box decoder device; - a smartphone; Petition 870250052526, dated 06 / 23 / 2025, page 30 / 66 25 / 25 - a digital media player device; - a TV set; - a mobile device; - a gaming device; - a tablet (or tablet computer); - a laptop; - a communication device. Petition 870250052526, dated 06 / 23 / 2025, page 31 / 66

Claims

1 / 4 CLAIMS 1. A method at a first access point (AP1) for detecting interference, said method CHARACTERIZED by comprising: detecting (S20) data traffic from a second access point (AP2) on a frequency channel (ch2), wherein the detected data traffic from the second access point (AP2) is not directed to the first access point (AP1); obtaining (S22) a signal strength level received on the frequency channel (ch2) when data traffic is not detected; sending (S24) an information item indicating that interference was detected on the frequency channel (ch2) according to the level obtained to the second access point (AP2).

2. Method, according to claim 1, CHARACTERIZED in that sending the information item comprises transmitting the information item on the frequency channel (ch2).

3. A method according to claim 1 or 2, characterized in that sending the information item comprises broadcasting the information.

4. Method, according to claim 1 or 2, CHARACTERIZED in that sending the information item comprises a unicast transmission of the information item to the second access point (AP2).

5. Method, according to any one of claims 1 to 4, CHARACTERIZED in that the first access point (AP1) and the second access point (AP2) are Wi-Fi access points.

6. Method, according to claim 5, CHARACTERIZED in that obtaining the signal strength level comprises performing a clean channel evaluation of the frequency channel (ch2).

7. Method, according to claim 5 or 6, CHARACTERIZED by Petition 870250052526, dated 06 / 23 / 2025, page 32 / 66 2 / 4 fact that the first access point (AP1) further comprises another wireless interface according to a ZigBee or Bluetooth type protocol.

8. Method according to claim 7, CHARACTERIZED in that the information item further includes an indication of the type of protocol that created the interference.

9. Method, according to any one of claims 1 to 8, CHARACTERIZED in that the information item further comprises a value that quantifies the detected interference.

10. Method at a second access point (AP2) to detect interference, said method CHARACTERIZED by comprising: sending and receiving (S25) data on a frequency channel (ch2), receiving (S27) from a first access point (AP1) an item of information indicating that interference has been detected according to a signal strength level obtained by the first access point (AP1) on the frequency channel (ch2) when data traffic from the second access point (AP2) is not detected, the data traffic not being directed to the first access point (AP1).

11. Method, according to claim 10, CHARACTERIZED in that it further comprises switching (S29) the second access point (AP2) to a second frequency channel to measure another strength level of another signal received on the second frequency channel.

12. First access point (AP1) configured to detect interference, said first access point (AP1) CHARACTERIZED by comprising: means to detect data traffic from a second access point (AP2) on a frequency channel (ch2), wherein the detected data traffic from the second access point (AP2) is not directed to the first access point (AP1); means to obtain a signal strength level of a received signal on the frequency channel (ch2) when data traffic is not detected; Petition 870250052526, dated 06 / 23 / 2025, page 33 / 66 3 / 4 means to send an information item indicating that interference was detected on the frequency channel (ch2) according to the level obtained to the second access point (AP2).

13. Second access point (AP2) configured to detect interference, said second access point (AP2) CHARACTERIZED by comprising: means for sending and receiving data on a frequency channel (ch2), means for receiving from a first access point (AP1) an item of information indicating that interference has been detected according to a signal strength level obtained by the first access point (AP1) on the frequency channel (ch2) when data traffic from the second access point (AP2) is not detected, the data traffic not being directed to the first access point (AP1).

14. System for detecting interference, the system CHARACTERIZED by comprising a first access point (AP1) and a second access point (AP2), wherein: the second access point (AP2) is configured to process data traffic on a frequency channel (ch2); the first access point (AP1) is configured to: detect data traffic from the second access point (AP2) on the frequency channel (ch2), where the data traffic is not directed to the first access point (AP1); obtain a signal strength level from a signal received on the frequency channel (ch2) when data traffic is not detected; send an information item to the second access point (AP2) to indicate that interference was detected on the frequency channel (ch2) according to the level obtained. Petition 870250052526, dated 06 / 23 / 2025, page 34 / 66 4 / 4 15. Storage media CHARACTERIZED by comprising the method defined in any one of claims 1 to 11. Petition 870250052526, dated 06 / 23 / 2025, p. 35 / 66

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