METHODS OF PERFORMING FREQUENCY HOPPING BY A DEVICE IN A FIRST WIRELESS COMMUNICATION NETWORK, AS WELL AS CORRESPONDING DEVICES AND A COMPUTER PROGRAM PRODUCT
Technical field
The present disclosure generally relates to the field of wireless communication and, more specifically, to an enhanced frequency hopping scheme for mitigating interference.
Background
In license-exempt frequency bands like 2.4 GHz ISM, 5 GHz, or 6 GHz, effective spectrum sharing mechanisms may be of importance, especially when transmissions are not restricted to very low power. The primary spectrum sharing methods are listen-before-talk, LBT, also referred to as carrier sense multiple access with collision avoidance, CSMA/CA, and frequency hopping, FH.
LBT, as the name implies, involves the transmitter determining if the channel is idle before initiating a transmission. If busy, the transmitter waits until the channel is available. This method is used in IEEE 802.11 , i.e. Wi-Fi operating in 2.4 GHz, 5 GHz, and 6 GHz, for example. On the other hand, FH, utilized by for example Bluetooth, BT, involves using a specific part of the band for a small fraction of the total time, leaving room for other transmissions.
Choosing between LBT and FH depends on factors such as channel bandwidth and dynamic usage. LBT is typically favoured for wider bandwidths with dynamic channel requirements, while FH typically suits narrowband systems with predictable channel usage.
However, both LBT and FH work effectively when all devices employ the same mechanism. Mismatched usage, such as LBT with FH, can lead to issues. For example, a wideband system using LBT may defer transmission due to detecting a narrowband signal, even if it wouldn't harm the narrowband system. Conversely, the wideband system may not detect a narrowband signal, potentially causing harmful interference.
In amongst the 2.4 GHz ISM band, coexistence challenges arise between Wi-Fi, using LBT, and Bluetooth, using FH. Bluetooth addresses this with adaptive FH, AFH, allowing devices to report and update channel conditions. A central node distributes a channel map to determine the operating channels for hopping. Bluetooth Low Energy, BLE, further minimizes interference to Wi-Fi by using three channels during initial link establishment, strategically avoiding the most commonly used non-overlapping Wi-Fi channels i.e., avoiding channels 1 , 6, and 11 in the 2.4 GHz band.
When a narrowband frequency hopping device has many available channels, it may not be advantageous to utilize all these available channels, especially when sharing the spectrum with other wireless technologies. Narrowband interference poses challenges to wideband systems in multiple ways.
Firstly, a narrowband transmission can restrict a wideband device's access to the medium, leading to inefficient resource utilization. Secondly, dealing with interference from a narrowband signal is challenging for wideband systems due to the concentrated power on a narrow bandwidth. Additionally, wideband systems struggle to mitigate narrowband interference, as seen when algorithms like Adaptive Frequency Hopping, AFH, designed to maximize frequency diversity are used, typically in Bluetooth.
Summary
It would be advantageous to achieve methods of performing frequency hopping by a device in a first wireless communication network, wherein the method takes into account its impact on a second wireless communication network operating in the same frequency band and/or takes deployment of this other wireless communication network operating in the same frequency band into account for improving the performance of the second wireless communication network.
It would further be advantageous to achieve corresponding devices and computer program products. In a first aspect of the present disclosure, a method of performing frequency hopping by a device in a first wireless communication network is provided, wherein said first wireless communication network operates in a first frequency range, which is at least partially overlapping with a second frequency range utilized for communication by a second wireless communication network, wherein the communication in the first wireless communication network utilizes frequency hopping on a first set of frequency channels within said first frequency range, and the second wireless communication network communicates on a second set of frequency channels within said second frequency range.
The method comprises the steps of: configuring, by the device, a subset of said set of frequency channels for performing said frequency hopping, said subset being based on information about operation on frequency channels of said second set of frequency channels in said second wireless communication network; performing, by said device, said frequency hopping within said subset of frequency channels.
The inventors have found that it may be beneficial if the frequency channels used for frequency hopping in the first wireless communication network are based on information about operation on frequency channels of the second set of frequency channels in the second wireless communication network.
The present disclosure is thus directed to a frequency hopping scheme for devices in the first wireless network to use in license exempt spectrum where the number of available frequency channels is larger than the number of channels that is needed for satisfactory operation. The method is based on a reduction of the number of operating frequency channels, i.e. the frequency channels used for the frequency hopping by the first device, based on information about operation on the frequency channels of the second set of frequency channels in the second wireless communication network. This improves coexistence with the second wireless communication network.
By taking advantage of the present disclosure, multiple advantages may be obtained.
First, the probability of interference caused by the first wireless communication network to the second wireless communication network may be reduced. This is, for example, accomplished by excluding frequency channels in the first set of frequency channels that “map” onto frequency channels, i.e. at least partially overlap with frequency channels, in the second wireless communication network that are being utilized by device in the second wireless communication network. These excluded frequency channels may thus not be part of the subset of frequency channels for performing the frequency hopping by the first device in the first wireless communication network.
Second, the performance of the first wireless communication network may be improved as the probability of interference experienced by devices in the first wireless communication network from device in the second wireless communication network may be reduced.
In wireless communication, frequency channels play a role in managing the allocation of the radio frequency spectrum. The radio frequency spectrum is divided into distinct frequency channels. These frequency channels represent specific frequencies on which wireless devices can transmit and receive signals.
Frequency hopping is a technique employed to improve the robustness and efficiency of wireless communication systems, particularly in the presence of interference. Instead of staying on a fixed frequency channel, a device utilizing frequency hopping switches between different frequency channels. This dynamic approach helps mitigate the impact of interference on a specific frequency channel.
The process of frequency hopping involves known sequences or patterns that dictate the order and timing of channel changes. This sequence is shared between devices, ensuring synchronized frequency hopping and allowing them to stay connected even as they move through different channels.
Frequency hopping spreads the communication over multiple frequencies, providing a level of resilience against interference and contributing to a more reliable and secure wireless communication environment.
In accordance with the present disclosure, the first wireless communication network utilizes frequency hopping on a first set of frequency channels. A device operating in the first wireless communication network may thus utilize all these frequency channels when performing frequency hopping. However, the inventors have found that it may be beneficial to limit the number of frequency channels utilized for frequency hopping in a specific way - i.e. the selection of frequency channels to be used for frequency hopping is made such that the impact on the second wireless communication network is reduced.
A subset of frequency channels of the first set of frequency channels may be created, wherein the subset is based on information on channels of the second wireless communication network and where the second wireless communication network operates within a same, i.e. at least partially overlapping, frequency span as the first wireless communication network.
In accordance with the present disclosure, the first set of frequency channels may be viewed as the first set of frequency hopping channels. This means that this first set of frequency channels may be used by the device for frequency hopping.
In an example, the information about operation on the frequency channels of the second set of frequency channels in said second wireless communication network comprises a-priori information on available frequency channels in said second wireless communication network.
The a-priori information may, for example, be related to the bandwidth of the frequency channels in the second wireless communication network. A-priori information may also be related to the specific frequencies used by the different channels in the second wireless communication network.
An example is provided for Wi-Fi. In, for example, the 2.4 GHz frequency band typically used by Wi-Fi, there are several aspects to consider regarding frequency channels. The 2.4 GHz spectrum is divided into multiple channels, typically ranging from 1 to 11 . Each channel occupies a specific frequency range within the 2.4 GHz band, and Wi-Fi devices can transmit and receive signals on these channels.
The standard channel width for Wi-Fi in the 2.4 GHz band is 20 MHz. However, in environments with less congestion, channel bonding may be utilized to combine adjacent channels and increase data throughput, resulting in 40 MHz or wider channels.
Channels 1 , 6, and 11 are often recommended for use in 2.4 GHz Wi-Fi deployments because they have minimal overlap. Using non-overlapping channels helps reduce interference between nearby Wi-Fi networks. The (a-priori) knowledge that these channels 1 , 6 and 11 are often primarily used in 2.4GHz Wi-Fi deployments can be used when creating the subset of the first set of frequency channels.
In another example, the information about operation on frequency channels of the second set of frequency channels in said second wireless communication network comprises current information on said operation on frequency channels of the second set of frequency channels. Current information being information on current operation of frequency channels of the second set of frequency channels. It may constitute actual, dynamic, or real-time information.
The inventors have found that current information about the frequency channels of the second set of frequency channels may be used in the selection of the subset of the first set of frequency channels. The current information, or real-time or dynamic information, may be interpreted as a dynamic snapshot of the current state of these frequency channels in the second wireless communication network.
When referring to Wi-Fi, the current information about frequency channels in the 2.4 GHz band for Wi-Fi may provide a dynamic snapshot of the current state of the wireless environment. Unlike a-priori information, which offers a static understanding of channel allocations and possible usage, real-time data may provide for constantly changing conditions in the wireless environment.
The first and second wireless communication network operate in a shared frequency spectrum. Real-time information with respect to frequency channel utilization in the second wireless communication network may aid in mitigating interference and optimizing channel usage within the first wireless communication network. That is, the frequency channels used for frequency hopping may be based on frequency channel utilization in the second wireless communication network.
In another example, the information about operation on frequency channels of the second set of frequency channels in said second wireless communication network comprises information about which frequency channels are key frequency channels in said second wireless communication network.
Two adjacent channels in the second wireless communication network may be combined to one single wide frequency channel. Typically, one of those two adjacent channels is then considered to be the key frequency channel. The key frequency channel may be regarded as a primary frequency channel.
In Wi-Fi networks operating in the 2.4 GHz band, for example, when using 40 MHz wide channels, the concept of primary frequency channels is applicable. When a Wi-Fi channel width is increased to 40 MHz, two adjacent 20 MHz channels may be bonded together to form a single 40 MHz channel. This allows for higher data transfer rates and increased network capacity.
The primary channels, which are often used as reference points, may include channels 1 , 6, and 11. These channels are particularly significant because they have minimal overlap with each other, reducing interference and ensuring efficient use of the available spectrum.
When configuring Wi-Fi networks with 40 MHz wide channels in the 2.4 GHz band, network administrators often align the channel bonding with these primary channels to optimize performance and minimize interference from neighbouring networks.
In, for example, the 5 GHz Wi-Fi spectrum, certain frequency channels are frequently designated as primary reference points, such as channels 36, 40, and 44. These channels may hold particular importance due to their non-overlapping characteristics, which reduces interference and improves spectrum utilization efficiency.
When setting up Wi-Fi networks with 80 MHz or wider channel widths in the 5 GHz range, network administrators commonly synchronize their channel bonding strategies with these primary channels. This alignment may be of importance to enhance network performance and reduce potential disruptions from adjacent networks.
The present disclosure may, for example, map the key frequency channels, i.e. the primary channels like 36, 40 and 44, to frequency channels in the first wireless communication network. Mapping means that the frequency channels in the first wireless communication network that share the same frequency spectrum as the primary channels like 36, 40, and 44 are selected. These selected frequency channels in the first wireless communication network may be excluded from the subset to prevent a relatively severe impact on the operation of the second wireless communication network.
In a further example, the method comprises the step of: determining, by said device, said information about said operation on frequency channels of the second set of frequency channels in said second wireless communication network.
The inventors have found that it may be beneficial if the device is able to actively determine the information about the operation on frequency channels of the second set of frequency channels in the second wireless communication network. For example, the device may determine that a particular frequency channel within the first set of frequency channels in the first wireless communication network is often not available. This may be caused by ongoing communications in a frequency channel in the second wireless communication network that “maps” on the particular frequency channel within the first set of frequency channels.
The device may then, for example, exclude all frequency channels within the first set of frequency channels in the first wireless communication network that “map” onto that frequency channel in the second wireless communication network. In this example, the frequency channels in the second wireless communication network may have a larger bandwidth compared to the frequency channels in the first wireless communication network.
In a further example, the device is further arranged for communicating in said second wireless communication network, and wherein said method comprises the step of: scanning, by said device, said frequency channels of the second set of frequency channels in said second wireless communication network for obtaining said information.
The device may be able to communicate within the first wireless communication network as well as to communicate in the second wireless communication network. If that’s the case, then the device may sense, scan, or observe the frequency channels of the second set of frequency channels in the second wireless network for obtaining the information.
The device may use this sensing, scanning, or observing in limiting the frequency channels in the first wireless communication network for frequency hopping.
In a further example, the method comprises the steps of: excluding, by said device, from said subset of frequency channels, all frequency channels of the first set of frequency channels in said first wireless communication network that map on a particular frequency channel of the second set of frequency channels in said second wireless communication network.
So, for example, the device may determine that a particular frequency channel in said first wireless communication network should optimally not be used for said frequency hopping and may determine a frequency channel in said second wireless communication network that maps on said particular frequency channel.
All frequency channels in the first set of frequency channels of the first wireless communication network that “map” onto that determined frequency channel in the second set of frequency channels, or at least partly overlap with that determined frequency channel in the second set of frequency channels, in the second wireless communication network may then be excluded from the subset of frequency channels available for frequency hopping.
In a typical scenario a Bluetooth wireless communication network coexists with a Wi-Fi wireless communication network. Both operating in the same frequency range. Wi-Fi may have 20 MHz width frequency channels. Bluetooth may have 1 MHz width frequency channels, with a 1 MHz guard band. The present disclosure may deselect, or exclude, or Bluetooth frequency channels that map on a particular Wi-Fi frequency channel. For example, it may be determined that a particular Wi-Fi channel, for example channel 1 in Wi-Fi operating in the 2.4GHz band, is utilized for Wi-Fi communication. In accordance with the present disclosure, all 1 MHz width Bluetooth channels that map onto channel 1 of the Wi-Fi wireless communication network may then be excluded from the frequency hopping algorithm. This will improve the efficiency of the Wi-Fi communication network.
In another example, the information about operation on frequency channels of the second set of frequency channels in said second wireless communication network comprises channel allocation information of said frequency channels of the second set of frequency channels in said second wireless communication network.
In yet another example, the method comprises the step of: ordering, by said device, said frequency channels of said first set of frequency channels in said first wireless communication network based on said information about operation on frequency channels of said second set of frequency channels in said second wireless communication network, wherein said step of configuring said subset comprises configuring, by said device, said subset of frequency channels of said first set frequency channels based on said ordered frequency channels.
In a further example, the first wireless communication network is a Bluetooth based communication network and/or the second wireless communication network is a Wi-Fi based communication network.
In a second aspect of the present disclosure, there is provided a device arranged for performing frequency hopping by a device in a first wireless communication network, wherein said first wireless communication network operates in a first frequency range, which is at least partially overlapping with a second frequency range utilized for communication by a second wireless communication network, wherein the communication in the first wireless communication network utilizes frequency hopping on a first set of frequency channels within said first frequency range, and the second wireless communication network communicates on a second set of frequency channels within said second frequency range.
The device comprising: configuring equipment arranged for configuring a subset of said set of frequency channels for performing said frequency hopping, said subset being based on information about frequency channels of said second set of frequency channels in said second wireless communication network; processing equipment arranged for performing said frequency hopping within said subset of frequency channels.
It is noted that the advantages as explained with respect to the first aspect of the present disclosure, being the method of performing frequency hopping by a device in a first wireless communication network, are also applicable to the second aspect of the present disclosure, being the device arranged for performing the frequency hopping in the first wireless communication network.
In an example, the information about operation on the frequency channels of the second set of frequency channels in said second wireless communication network comprises a-priori information on available frequency channels in said second wireless communication network.
In a further example, the information about operation on frequency channels of the second set of frequency channels in said second wireless communication network comprises current information on said operation on frequency channels of the second set of frequency channels in said second wireless communication network.
In yet another example, the information about operation on frequency channels of the second set of frequency channels in said second wireless communication network comprises information about which frequency channels are primary frequency channels in said second wireless communication network.
In an example, the processing equipment is further arranged for determining said information about said operation on frequency channels of the second set of frequency channels in said second wireless communication network.
In a further example, the device is further arranged for communicating in said second wireless communication network, and wherein said device further comprises: scanning equipment arranged for scanning said frequency channels of the second set of frequency channels in said second wireless communication network for obtaining said information.
In yet another example, the processing equipment is further arranged for excluding from said subset of frequency channels, all frequency channels of the first set of frequency channels in said first wireless communication network that at least partially overlap with, i.e. map on, a particular frequency channel of the second set of frequency channels in said second wireless communication network.
In an example, the information about operation on frequency channels of the second set of frequency channels in said second wireless communication network comprises channel allocation information of said frequency channels of the second set of frequency channels in said second wireless communication network.
In a further example, the processing equipment is further arranged for ordering said frequency channels of said first set of frequency channels in said first wireless communication network based on said information about operation on frequency channels of said second set of frequency channels in said second wireless communication network, and wherein said configuring equipment is further arranged for configuring said subset comprises configuring, by said device, said subset of frequency channels of said first set frequency channels based on said ordered frequency channels.
In yet another example, the first wireless communication network is a Bluetooth based communication network and/or the second wireless communication network is a Wi-Fi based communication network.
In a third aspect of the present disclosure, there is provided a computer program product comprising a computer readable medium having instructions stored thereon which, when executed by a device in a first wireless communication network, cause said device to implement a method in accordance with any of examples as provided above.
The present disclosure is described in conjunction with the appended figures. It is emphasized that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.
In the appended figures, similar components and/or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.
The above and other aspects of the disclosure will be apparent from and elucidated with reference to the examples described hereinafter.
Brief description of the drawings Fig. 1 discloses an example of a communication system having a first and a second wireless communication network;
Fig. 2 discloses an example of a device for operation in a first wireless communication network, in accordance with the present disclosure;
Fig. 3 discloses an example of spectrum sharing between the first and second wireless communication networks;
Fig. 4 discloses an example of a device able to communicate in the first as well as in the second wireless communication network;
Fig. 5 discloses an example of a flow chart of a method in accordance with the present disclosure.
Detailed description
It is noted that in the description of the figures, same reference numerals refer to the same or similar components performing a same or essentially similar function.
A more detailed description is made with reference to particular examples, some of which are illustrated in the appended drawings, such that the manner in which the features of the present disclosure may be understood in more detail. It is noted that the drawings only illustrate typical examples and are therefore not to be considered to limit the scope of the subject matter of the embodiments. The drawings are incorporated for facilitating an understanding of the disclosure and are thus not necessarily drawn to scale. Advantages of the subject matter as claimed will become apparent to those skilled in the art upon reading the description in conjunction with the accompanying drawings.
The ensuing description above provides preferred exemplary embodiment(s) only, and is not intended to limit the scope, applicability or configuration of the disclosure. Rather, the ensuing description of the preferred exemplary embodiment(s) will provide those skilled in the art with an enabling description for implementing a preferred exemplary embodiment of the disclosure, it being understood that various changes may be made in the function and arrangement of elements, including combinations of features from different embodiments, without departing from the scope of the disclosure.
Unless the context clearly requires otherwise, throughout the description and the embodiments, the words "comprise," "comprising," and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to." As used herein, the terms "connected," "coupled," or any variant thereof means any connection or coupling, either direct or indirect, between two or more elements; the coupling or connection between the elements can be physical, logical, electromagnetic, or a combination thereof. Additionally, the words "herein," "above," "below," and words of similar import, when used in this application, refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the Detailed Description using the singular or plural number may also include the plural or singular number respectively. The word "or," in reference to a list of two or more items, covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list.
These and other changes can be made to the technology in light of the following detailed description. While the description describes certain examples of the technology, and describes the best mode contemplated, no matter how detailed the description appears, the technology can be practiced in many ways. Details of the system may vary considerably in its specific implementation, while still being encompassed by the technology disclosed herein. As noted above, particular terminology used when describing certain features or aspects of the technology should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the technology with which that terminology is associated. In general, the terms used in the following embodiments should not be construed to limit the technology to the specific examples disclosed in the specification, unless the Detailed Description section explicitly defines such terms. Accordingly, the actual scope of the technology encompasses not only the disclosed examples, but also all equivalent ways of practicing or implementing the technology under the embodiments.
Referring now to the drawing figures, in which like elements are referred to by like reference numerals, there is shown in FIG. 1 a schematic diagram of a communication system 10, according to an example, which comprises a plurality of narrowband wireless devices 16a and 16b, referred to collectively as narrowband wireless devices 16, which may form a first wireless communication network 15, such as a Bluetooth communication network. A narrowband wireless device 16 is configured to include a frequency hopping, FH, unit 18 which is configured to perform frequency hopping using available channels within the first wireless communication network.
Communication system 10 further includes a plurality of wideband wireless devices 12a and 12b, referred to collectively as wideband wireless devices 12, which may form a second wireless communication network 13, such as a Wi-Fi communication system. A wideband wireless device 12 is configured to include a listen before talk, LBT, unit 14, which is configured for checking if a frequency channel is clear before transmitting on that frequency channel to avoid collisions.
Note that although only two narrowband wireless devices 16 and two wideband wireless devices 12 are shown for convenience, the communication system may include many more narrowband wireless devices 16 and wideband wireless devices 12.
Furthermore, it is to be understood that a narrowband wireless device 16 may also be capable of wideband communication, and a wideband wireless device 12 may also be capable of narrowband communication, such that a single wireless device may be either or both of a narrowband wireless device 16 and/or a wideband wireless device 12, depending on the context, use case, configuration, etc.
For example, a wireless device may be configured for both Bluetooth capability and Wi-Fi capability, such that when it is communicating via Bluetooth, it is referred to as a narrowband wireless device 16, whereas when it is communicating via Wi-Fi, it may be referred to as a wideband wireless device 12. Such a wireless device is shown in figure 4.
The method in accordance with the present disclosure may be most effective in situations wherein the first wireless communication network utilizes frequency channels that have a smaller bandwidth compared to the bandwidth of the frequency channels utilized in the second wireless communication network.
So, the device in the first wireless communication network may be referred to as a narrowband wireless device. The method in accordance with the present disclosure may be viewed as a detailed version of adaptive frequency hopping, which is a technique used in wireless communication, like Bluetooth, where devices continuously switch between different frequency channels in a synchronized manner to avoid interference and maintain a stable connection; this dynamic hopping pattern is adjusted based on information on frequency channels of a second wireless communication network to optimize performance.
It is further noted that the second wireless communication network might not utilize a frequency hopping mechanism. Communications between devices and/or between devices and an Access Point, AP, may be performed using one frequency channel.
Example implementations, in accordance with an example, of the narrowband wireless device 16 discussed in the preceding paragraphs will now be described with reference to FIG. 2. In a communication system 10, the narrowband wireless device 16 may have hardware 20 that may include a radio interface 22 configured to set up and maintain a wireless connection with one or more other narrowband wireless devices 16 in a first wireless communication network 13. The radio interface 22 may be formed as or may include, for example, one or more RF transmitters, one or more RF receivers, and/or one or more RF transceivers.
The hardware 20 of the narrowband wireless device 16 further includes processing circuitry 24. The processing circuitry 24 may include a processor 26 and memory 28. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 24 may comprise integrated circuitry for processing and/or control, e.g., one or more processors and/or processor cores and/or FPGAs (Field Programmable Gate Array) and/or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor 26 may be configured to access (e.g., write to and/or read from) memory 28, which may comprise any kind of volatile and/or nonvolatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory).
Thus, the narrowband wireless device 16 may further comprise software 30, which is stored in, for example, memory 28 at the narrowband wireless device 16, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the narrowband wireless device 16. The software 30 may be executable by the processing circuitry 24.
The processing circuitry 24 may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by narrowband wireless device 16.
The processor 26 corresponds to one or more processors 26 for performing narrowband wireless device 16 functions described herein. The narrowband wireless device 16 includes memory 28 that is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software 30 may include instructions that, when executed by the processor 26 and/or processing circuitry 24, causes the processor 26 and/or processing circuitry 24 to perform the processes described herein with respect to narrowband wireless device 16. For example, the processing circuitry 24 of the narrowband wireless device 16 may include a FH unit 14 arranged for configuring a subset of the set of frequency channels for performing the frequency hopping.
The method in accordance with the present disclosure is now discussed with reference to figure 3. Figure 3 shows an example wherein a first wireless communication network, being a Bluetooth based communication network, shares a frequency spectrum with a second wireless communication network, being a Wi-Fi based communication network.
The Wi-Fi based communication network utilizes a plurality of frequency channels. Figure 3 shows three frequency channels, being channel 1 , channel 6 and channel 11. These three channels 1 , 6 and 11 do not overlap and are, therefore, often used from a pragmatic point of view. In between the channels 1 and 6, and in between the channels 6 and 11 , other frequency channels are located but are omitted for readability purposes. Typically, in the 2.4GHz range, the frequency channels of the WiFi based communication network are 20MHz wide. In the 2.4 GHz band, the Wi-Fi channels are typically spaced 5 MHz apart from each other. The center frequencies of the standard Wi-Fi channels start from 2.412 GHz, channel 1 , and increase by 5 MHz increments for each subsequent channel. The Bluetooth based communication network utilizes many more frequency channels. Typically, about 79 frequency channels are used, each about 1 MHz width. These frequency channels are not overlapping.
It is noted that the Bluetooth based communication network utilizes frequency hopping. A device operating in the Bluetooth based communication network hops from one frequency channel to another in accordance with a particular hopping pattern.
The Wi-Fi based communication network does not utilize such a hopping scheme. A device in a Wi-Fi based communication network typically uses one frequency channel for communication. For example, channel 1 is allocated for communications for a particular Wi-Fi enabled device.
The present disclosure is directed to a mechanism to limit the number of utilized frequency channels in the Bluetooth based communication network. The number of available frequency channels is not limited in an arbitrary manner. A subset of the frequency channels is created based on knowledge about the frequency channels in use by Wi-Fi communication network.
Some specific examples are elucidated here below for a better understanding of the present disclosure.
In this disclosure a method for a (narrowband) frequency hopping device in a first wireless communication network is disclosed, wherein the device is to choose a subset of operating frequency channels out of a larger set of available channels with the goal to either limit its negative impact on a second wireless communication network and/or to improve its own performance within the first wireless communication network.
The device does so by selecting a subset of the available frequency channels as its operating channels, based on knowledge about the second wireless communication network and, more specifically, on knowledge about the channels in use in the second wireless communication network.
The number of frequency channels in the subset can be any integer N that is smaller than the total number of available channels M, i.e., N<M. Throughout operation the device may keep updating the selection of the available frequency channels and may replace the subset of operating channels based on the new selection such that it operates at any N channels, when they are available. The below provided example will be explained using Bluetooth and Wi-Fi for the first wireless communication network and the second wireless communication network, however it is not limited to these standards I technologies.
As mentioned above, the performance within the first wireless communication network may be improved using the method in accordance with the present disclosure. By excluding problematic, or “likely problematic” channels from the hopping sequence in the first wireless communication network, devices can avoid potential sources of interference altogether.
This proactive approach may ensure that the communication remains uninterrupted and of high quality. Moreover, in environments where multiple devices coexist, selectively excluding problematic channels can reduce the chances of collisions and contention, allowing each device to transmit and receive data more efficiently.
In one example, aiming to enhance coexistence with a Wi-Fi system, a Bluetooth, BT, device arranges, or orders, the available operating channels based on their potential impact on blocking or interfering with the Wi-Fi system on a 20 MHz channel in use in the Wi-Fi system.
The ordering considers factors like whether the channel is a primary, i.e. key, frequency channel or not, or secondary, i.e., the less critical segments of a wideband channel. For instance, it may prioritize using frequency hopping channels that match wideband channels in the secondary 80 MHz channel rather than the primary 80 MHz channel in a broader 160 MHz channel.
Determining which frequency channels are the primary 20 MHz channels may not be immediately apparent. However, this information can be obtained in several ways. For example, a-priori information may be used, such as being mandated by a regulatory document like ETSI EN 303 687. The device may also utilize a Wi-Fi radio by actively scanning if such a device supports both Wi-Fi and BT and shares an interface between BT and Wi-Fi on the chip, or making an educated guess based on "preferred frequency channels", or “preferred scanning channels”. Preferred frequency channels are, for example, channels 1 , 6 and 11 in traditional 2.4GHz Wi-Fi Systems.
Through the use of the method in accordance with the present disclosure, the impact on the Wi-Fi communication network can be reduced by giving priority to those frequency channels in the Bluetooth network that affect the Wi-Fi channels (that are actually being used in the Wi-Fi network) the least.
By operating on a limited set of available frequency channels, Bluetooth operation becomes more predictable for the Wi-Fi communication network. This predictability provides opportunities for the Wi-Fi communication network to adjust its own operation accordingly.
A scenario affecting coexistence arises when the Bluetooth, BT, system communicates using isochronous channels, adding complexity because the Downlink, DL, and Uplink, UL, communication does not occur on the same frequency channel. Furthermore, the number of used uplink frequency channels may vary based on how many peripheral devices a central device communicates with, potentially reaching up to 31 peripherals. This variation increases the potential interference or blockage generated by Bluetooth communication.
In another approach, the ordering of operating channels for peripheral devices is determined by whether the channel falls within the same 20 MHz Wi-Fi channel as the central channel. This concentration of interference or blockage into the same WiFi channel aligns with the probability of interfering with multiple Wi-Fi transmissions.
In situations where there are more peripheral devices than BT channels in a 20 MHz bandwidth, additional frequency channels may be selected in an adjacent 20 MHz bandwidth belonging to the same Wi-Fi wideband channel or, similarly to the previous case, chosen with potentially the least impact on the Wi-Fi communication network.
In another example, the device arranges the channels based on the perceived channel conditions and operates only on a subset that corresponds to channels with the highest likelihood of successful communication, wherein this selection considers the frequency channels in use by the second wireless communication system. The criteria for ordering frequency channels could include factors like experienced interference strength or the amount of detected interference time on the channel.
To illustrate, let us consider a grading system where each channel is assigned a value from 0 to 1 in increments of 0.1. A value of 0 might indicate a channel deemed entirely unusable, while 1.0 would represent a channel perfect for communication. Intermediate values, such as 0.3, could be assigned based on the expected probability of successful transmission without negatively affecting the second wireless communication network — indicating a 30% chance of success and a 70% chance of failure due to interference.
Unlike a binary block list that simply indicates whether a channel should be used for Frequency Hopping, FH, or not, a non-binary channel quality list provides more flexibility. The decision to include a channel in the set used for frequency hopping may then not only depend on the condition of that specific channel but may also consider its relative quality compared to other channels. For example, if a particular channel is graded as 0.5, its inclusion in the subset may depend on the grades of other channels.
If many other channels have higher grades, indicating a higher probability of successful transmission and/or without harming a second wireless communication network operating in the same frequency band, the specific channel might be blacklisted. Conversely, if all other channels are graded lower, the channel may be considered relatively good and included in the FH set.
When causing interference to wideband systems that carry (very) different types of traffic, the consequences of the interference can vary significantly, even if the number of interfered packets in the different wideband systems is identical. For example, if one wideband system handles best-effort or background traffic, a relatively high packet loss rate might be tolerable. On the other hand, if another wideband system supports voice, XR, or VR applications, packet loss could have a substantial impact. Traditional approaches focus on coexistence at the physical layer, aiming to minimize collisions and similar issues.
In certain situations, such as when a narrowband system utilizing Frequency Hopping, FH, struggles to find completely unused channels, it might be preferred to interfere with a wideband system serving a less critical application. This choice could be made even if the impact on the physical layer is equally large or even larger compared to interfering with a wideband system supporting applications with low latency or high reliability requirements.
Therefore, according to this approach, the FH system's selection of hopping channels is influenced, at least in part, by the specific application requirements supported by the second wireless communication network. In yet another example, to illustrate the distinctions between the methods in this disclosure and known approaches, a simplified scenario is considered. Consider a Narrowband Frequency Hopping, NBFH, pair, consisting of a transmitter and receiver, operating near a Wi-Fi communication network with a 40 MHz bandwidth and low activity, such as a low duty cycle of 10%.
The 40 MHz Wi-Fi channel comprises a primary 20 MHz channel and a secondary 20 MHz channel. In conventional methods like Adaptive Frequency Hopping, AFH, observing the same level of operation on both Wi-Fi channels (10% duty cycle on both primary and secondary channels) would lead the NBFH pair to randomly operate on either or both 20 MHz portions with equal probability over time.
In contrast, the present disclosure deviates from this by consistently selecting the non-primary channel for NBFH use, even when the Wi-Fi activities on both channels are the same. This choice is made because, although the conditions experienced by NBFH devices on the two links are identical, operating on the nonprimary channel reduces the impact on Wi-Fi operations. The primary channel is of importance for Wi-Fi operations, while the secondary channel is of lesser importance from the Wi-Fi perspective.
Figure 4 shows an example 101 of a device that is able to communicate in the first wireless communication network as well as in the second wireless communication network. The first wireless communication network being the Bluetooth 102 based communication network and the second wireless communication network being the Wi-Fi 103 based communication network.
In this particular case, the device may be able to scan the frequency channels of the second wireless communication network. The information obtained may be used for creating the subset of frequency channels, in the first wireless communication network, wherein the subset of frequency channels is utilized for frequency hopping by the device.
Figure 5 shows a method 201 in accordance with an example of the present disclosure. The method is directed to performing frequency hopping by a device in a first wireless communication network, wherein said first wireless communication network operates in a first frequency range, which is at least partially overlapping with a second frequency range utilized for communication by a second wireless communication network, wherein the communication in the first wireless communication network utilizes frequency hopping on a first set of frequency channels within said first frequency range, and the second wireless communication network communicates on a second set of frequency channels within said second frequency range.
The method comprises the steps of: configuring 202, by the device, a subset of said set of frequency channels for performing said frequency hopping, said subset being based on information about operation on frequency channels of said second set of frequency channels in said second wireless communication network; performing 203, by said device, said frequency hopping within said subset of frequency channels.
To reduce the number of claims, certain aspects of the technology are presented below in certain claim forms, but the applicant contemplates the various aspects of the technology in any number of claim forms. For example, while some aspect of the technology may be recited as a computer-readable medium claim, other aspects may likewise be embodied as a computer-readable medium claim, or in other forms, such as being embodied in a means-plus-function claim.
In the description above, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of implementations of the disclosed technology. It will be apparent, however, to one skilled in the art that embodiments of the disclosed technology may be practiced without some of these specific details.
Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope thereof.