WO2025149558A1 - Slow preamble puncturing - Google Patents

Abstract

A wideband, WB, wireless device is provided. The WB wireless device is configured to operate communication according to a listen-before-talk, LBT, procedure over a multitude of resource units, RUs, forming a primary channel and one or more secondary channels to transmit a PHY protocol data unit, PPDU, wherein a PPDU bandwidth is equal to frequencies covered by the RUs for LBT procedure. The WB device is further configured to modify, when narrowband, NB, interference is present in a first secondary channel during a first LBT procedure, the PPDU bandwidth by removing one or more RUs in the first secondary channel, perform a subsequent second LBT procedure for the modified PPDU bandwidth, and transmit a PPDU with the modified PPDU bandwidth after the second LBT procedure.

Description

SLOW PREAMBLE PUNCTURING

FIELD

The present disclosure relates to wireless communications, and in particular, to configurations for preamble puncturing.

INTRODUCTION

Wi-Fi, also known as Wireless Local Area Network (WLAN), is a technology that currently mainly operates on the 2.4 GHz band or the 5 GHz band. There are specifications regulating an access points' or wireless terminals' physical (PHY) layer, medium access layer (MAC) layer and other aspects in order to ensure compatibility and inter-operability between different WLAN entities, e.g., between an access point and mobile terminals, both of which may be referred to as stations (STAs) herein. Wi-Fi is generally operated in unlicensed bands, and as such, communication over Wi-Fi may be subject to interference sources from any number of known and unknown devices. Wi-Fi is commonly used as wireless extensions to fixed broadband access, e.g., in domestic environments and hotspots, like airports, train stations and restaurants.

Wireless Coexistence

When operating in unlicensed bands, e.g., the 2.4 GHz ISM, the 5 GHz band, or the 6 GHz band, some means of spectrum sharing mechanism is typically required unless the transmissions are limited to use a very low power. Two example spectrum sharing mechanisms are listen-before-talk (LBT), also referred to as carrier sense multiple access with collision avoidance (CSMA/CA) and frequency hopping (FH).

The working procedure of LBT is as the name suggests. Before a transmission can be initiated, the transmitter listens on the channel to determine whether it is idle or if there is already another transmission ongoing. If the channel is found to be idle, the transmission can be initiated, whereas if the channel is found to be busy, the transmitter must deter from transmission and essentially keeps sensing the channel until it becomes idle. LBT is used by different versions of IEEE 802.11, commonly referred to as Wi-Fi, operating in e.g., 2.4 GHz ISM (Industrial, Scientific and medical) band as well as in the 5 GHz and 6 GHz bands. LBT is also employed by standards developed by 3GPP operating in the 5 GHz band, e.g., NR-U (New Radio-Unlicensed). If FH is used, the spectrum sharing is based on only using a specific part of the band for a relatively small fraction of the total time, leaving room for other transmissions. FH is the approach used by Bluetooth (BT).

Whether to employ LBT or FH is not obvious, but typically LBT is the preferred approach if the used channel bandwidth is relatively large, for example, 20 MHz or more, and the required usage of the channel is very dynamic with a lot of variance. FH, on the other hand, is well suited for narrowband systems where the occupied bandwidth is much less (on the order of 1 or 2 MHz) and a predictable, deterministic channel usage is required. Although both LBT and FH can be viewed as effective spectrum sharing mechanisms, both typically only work well if all devices use the same spectrum sharing mechanism. That is, if all devices apply LBT or use FH the devices tend to work well. However, if some devices use LBT whereas others use FH the devices may not be working properly. As one example, a wideband system using LBT may detect the narrowband transmission and defer from transmitting although such a transmission would have been successful without noticeable harm to the narrowband system. Conversely, the wideband system may not detect a narrowband system, since the average sensed power, within the wideband channel is relatively low, and then initiate at transmission that potentially can result in harmful interference to the narrowband system.

The above situation is present in the 2.4 GHz ISM band where Wi-Fi uses LBT, whereas BT uses FH. To allow for good coexistence between the two standards, BT has developed support for adaptive FH (AFH), which means that BT devices detect if there are Wi-Fi transmissions on some of the Wi-Fi channels, and then adapt the hopping pattern used for FH such that the frequencies coinciding with a Wi-Fi channel are not used (such channels are termed herein as blacklisted channels). In Bluetooth LE (BLE), additional specific measures are taken to limit the interference to Wi-Fi, by only using three channels for the initial link establishment, and where these three channels are selected such that, e.g., in the 2.4 GHz ISM band they do not overlap with the three most used WiFi channels, i.e., channels 1, 6 and 11.

Preamble Puncturing in IEEE 802.11

A feature introduced in the IEEE 802.1 lax ('High Efficiency', HE) amendment is ‘preamble puncturing’. It allows a HE station (STA) to transmit or receive a PHY protocol data unit (PPDU) over a channel even when a portion of the channel bandwidth is not occupied by that transmitted or received PPDU. In other words, the corresponding portion of the bandwidth of the entire PPDU is left empty, including the preamble as well as data fields. It is important to note that the mechanism is only applied to the preamble, where 'holes' of 20 MHz size are transmitted with zero energy, which leads to the punctured preamble. In the remaining part, HE's capability to assign different parts of the frequency band to the users by allocating 'Resource Units' (RUs), is applied, such that the 20 MHz holes are allocated to no user. As a result, no energy is transmitted in these holes either during the data part of the PPDU. Hence, by combining 'preamble puncturing' with a matching RU allocation, the entire PPDU may be considered punctured.

The typical usage of ‘preamble puncturing’, hereafter referred to as ‘puncturing’, is when certain portions of the operating bandwidth of a BSS are either assessed to be unavailable based on rules and regulations applicable in the presence of incumbents with higher priority (such as radar signals), or assessed to be ‘busy’ due to presence of OBSS signals, interference, or noise.

As the ‘puncturing’ of the data part is based on assigning RUs to the recipient(s) of the PPDU, in HE it is limited to the valid RU assignments defined by HE's orthogonal frequency division multiple access (OFDMA) based multi-user transmissions. The IEEE 802.1 Ibe Extremely High Throughput (EHT) amendment extends the flexibility of RU assignments to support many more bandwidth splits involving OFDMA as well as OFDM transmissions to a single user.

According to the HE and EHT amendments, the ‘preamble puncturing’ granularity for an HE as well as EHT PPDU is 20 MHz. For example, a 20 MHz portion can be punctured in 80 MHz channel, or a 40 MHz portion can be punctured in 160 MHz channel. Thus, aggregate bandwidths such as 60 MHz or 120 MHz are possible in EHT.

Narrowband (NB) interference to a wideband (WB) system may be problematic in a few different ways. Firstly, a NB transmission may prevent a WB device from accessing the communication medium which may be considered wasteful as many resources then become left unused since the use of, for example, only 1 MHz of spectrum may cause a 160 MHz channel to be unused as shown in the diagram of FIG. 1. Secondly, it may be very difficult for the WB system to deal with the interference from a narrowband signal due to the very highly concentrated power on a very narrow bandwidth.

Hence, existing systems may suffer from various coexistence issues.

SUMMARY

Aspects of the invention are provided by appended independent claims, and embodiments thereof are provided by appended dependent claims.

Some embodiments advantageously provide methods, systems, and apparatuses for preamble puncturing in wireless communication systems.

In one or more embodiments, puncturing is proposed when a wideband transmitter is subjected to narrowband interference. The implementation considers that ideal puncturing may be very hard to achieve due to the limited processing time between detecting interference until transmission occurs.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present embodiments, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:

FIG. 1 is a diagram of example showing how a NBFH transmission may block a WB transmission leading to large spectral inefficiencies;

FIG. 2 is a schematic diagram of an example network architecture illustrating a communication system according to the principles in the present disclosure;

FIG. 3 is a block diagram of an AP communicating with a Non-AP STA over an at least partially wireless connection according to some embodiments of the present disclosure; FIG. 4 is a flowchart of an example process in an non-AP STA according to some embodiments of the present disclosure;

FIG. 5 is an example schematic showing how the subsequent punctured PPDU pattern is chosen based on the channel sensing according to some embodiment of the present disclosure;

FIG. 6 is another example schematic showing how the subsequent punctured PPDU pattern is chosen based on the channel sensing according to some embodiment of the present disclosure;

FIG. 7 is a diagram of a performance plot showing the FTP download delay of a 10 MB file with different coexistence mechanisms in a scenario where 1-6 BT devices acts as interferers according to some embodiments of the present disclosure; and

FIG. 8 is a diagram of a performance plot showing the gaming delay of cloud gaming user with different coexistence mechanisms in a scenario where 1-6 BT devices acts as interferers according to some embodiments described herein.

DETAILED DESCRIPTION

There exists a need to improve the coexistence between a WB and a NB system and specifically it may be beneficial to the WB system to reduce its operating bandwidth, by using for example, puncturing, in order to try and avoid NB devices.

However, it may be very challenging to do this because puncturing cannot be fully dynamic in most implementations. This is due to the very limited time between detecting the narrowband interference and having to perform the transmission, which may not leaving sufficient time to reassemble the data unit for transmission.

Thus, there exists a need for an efficient yet feasible puncturing algorithm for avoidance of NB interferers.

One or more embodiments described herein solve one or more problems with existing systems by, for example, providing a puncturing algorithm for avoiding NB interferences.

Before describing in detail example embodiments, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to preamble puncturing based on, for example, PHY protocol data unit (PPDU) resizing. Accordingly, components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. Like numbers refer to like elements throughout the description.

As used herein, relational terms, such as “first” and “second,” “top” and “bottom,” and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the concepts described herein. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

In embodiments described herein, the joining term, “in communication with” and the like, may be used to indicate electrical or data communication, which may be accomplished by physical contact, induction, electromagnetic radiation, radio signaling, infrared signaling or optical signaling, for example. One having ordinary skill in the art will appreciate that multiple components may interoperate and modifications and variations are possible of achieving the electrical and data communication.

In some embodiments described herein, the term “coupled,” “connected,” and the like, may be used herein to indicate a connection, although not necessarily directly, and may include wired and/or wireless connections.

In some embodiments, the term “access point” or “AP” is used interchangeably and may comprise, or be, a network node. The AP may include any of base station (BS), radio base station, base transceiver station (BTS), base station controller (BSC), radio network controller (RNC), g Node B (gNB), evolved Node B (eNB or eNodeB), Node B, multi-standard radio (MSR) radio node such as MSR BS, multi -cell/multicast coordination entity (MCE), relay node, integrated access and backhaul (IAB), donor node controlling relay, radio access point (AP), transmission points, transmission nodes, Remote Radio Unit (RRU) Remote Radio Head (RRH), a core network node (e.g., mobile management entity (MME), self-organizing network (SON) node, a coordinating node, positioning node, MDT node, etc.), an external node (e.g., 3rd party node, a node external to the current network), nodes in distributed antenna system (DAS), a spectrum access system (SAS) node, an element management system (EMS), etc. The AP may also comprise test equipment. The AP may comprise a radio router, a radio transceiver, WiFi access point, wireless local area network (WLAN) access point, a network controller, etc.

In some embodiments, the non-limiting term “device” is used to describe a wireless device (WD) and/or user equipment (UE) that may be used to implement some embodiments of the present disclosure. In some embodiments, the device may be and/or comprise an access point (AP) station (STA). In some embodiments, the device may be and/or comprise a non-access point station (non-AP STA). In some embodiments, the device may be any type of device capable of communicating with a network node, such as an AP, over radio signals. The device may be any radio communication device, target device, a portable device, device-to-device (D2D) device, machine type device or device capable of machine to machine communication (M2M), low-cost and/or low-complexity device, a sensor equipped with a device, a computer, Tablet, mobile terminals, smart phone, laptop embedded equipped (LEE), laptop mounted equipment (LME), USB dongles, Customer Premises Equipment (CPE), an Internet of Things (loT) device, or a Narrowband loT (NB-IOT) device, Reduced Capability (RedCap) device, etc.

A device may be considered a network node and may include physical components, such as processors, allocated processing elements, or other computing hardware, computer memory, communication interfaces, and other supporting computing hardware. The network node may use dedicated physical components, or the node may be allocated use of the physical components of another device, such as a computing device or resources of a datacenter, in which case the network node is said to be virtualized. A network node may be associated with multiple physical components that may be located either in one location, or may be distributed across multiple locations.

Even though the descriptions herein may be explained in the context of one of a Downlink (DL) and an Uplink (UL) communication, it should be understood that the basic principles disclosed may also be applicable to the other of the one of the DL and the UL communication. In some embodiments in this disclosure, the principles may be considered applicable to a transmitter and a receiver. For DL communication, the AP station may be the transmitter and the receiver is the non-AP station. For the UL communication, the transmitter may be the non-AP station and the receiver is the AP station.

Note also that some embodiments of the present disclosure may be supported by an Institute of Electrical Engineers (IEEE) 802. 11 standard. IEEE 802.11 denotes a set of Wireless Local Area Network (WLAN) air interface standards developed by the IEEE 802.11 committee for short-range communications (e.g., tens of meters to a few hundred meters). Some embodiments may also be supported by standard documents disclosed in Third Generation Partnership Project (3GPP) technical specifications. That is, some embodiments of the description can be supported by the above documents. In addition, all the terms disclosed in the present document may be described by the above standard documents.

Note that although terminology from one particular wireless system, such as, for example, IEEE 802. 11, 3rd Generation Partnership Project (3GPP), Long Term Evolution (LTE), 5th Generation (5G) and/or New Radio (NR), may be used in this disclosure, this should not be seen as limiting the scope of the disclosure to only the aforementioned system. Other wireless systems, including without limitation Wide Band Code Division Multiple Access (W CDMA), Worldwide Interoperability for Microwave Access (WiMax), Ultra Mobile Broadband (UMB) and Global System for Mobile Communications (GSM), may also benefit from exploiting the ideas covered within this disclosure. Note further, that functions described herein as being performed by one or more of a STA, AP, non-AP STA, wireless device, network node, etc., may be distributed over a plurality of STAs, APs, non-AP STAs, wireless devices, network nodes, etc. In other words, it is contemplated that the functions of the devices described herein are not limited to performance by a single physical device and, in fact, can be distributed among several physical devices.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Some embodiments provide configurations for preamble puncturing. Referring again to the drawing figures, in which like elements are referred to by like reference numerals, there is shown in FIG. 2 a schematic diagram of the communication system 10, according to one embodiment, constructed in accordance with the principles of the present disclosure. The communication system 10 in FIG. 2 is a non-limiting example and other embodiments of the present disclosure may be implemented by one or more other systems and/or networks. Referring to FIG. 2, system 10 may comprise a wireless local area network (WLAN). The devices in the system 10 may communicate over one or more spectrums, such as, for example, an unlicensed spectrum, which may include frequency bands typically used by Wi-Fi technology. One or more of the devices may be further configured to communicate over other frequency bands, such as shared licensed frequency bands, etc. The system 10 may include one or more coverage areas 12a, 12b, etc. (collectively referred to herein as “coverage area 12”), which may be defined by corresponding access points (APs) 14a, 14b, etc. (collectively referred to herein as “AP 14”). The AP 14 may or may not be connectable to another network, such as a core network over a wired or wireless connection. The system 10 includes a plurality of non-AP devices, such as, for example, non-AP STAs 16a, 16b, 16c (collectively referred to as non-AP STAs 16). The system 10 may include a plurality of narrowband (NB) non-AP devices 17a, 17b, etc. (collectively referred to as NB non-AP STAs 17). NB non-AP STAs may operating according to one or more frequency hopping scheme where NB non-AP STAs may be configured to perform frequency hopping based in part on the punctured preambles described herein. Each of the non-AP STAs 16 may be located in one or more coverage areas 12 and may be configured to wirelessly connect to one or more AP 14. Note that although two APs 14a and 14b and two non-AP STAs 16a and 16b are shown for convenience, the communication system may include many more non-AP STAs 16 and APs 14. Each AP 14 may connect to/serve/configure/schedule/etc. one or more non-AP STAs 16.

It should be understood that the system 10 may include additional nodes/devices not shown in FIG. 2. In addition, the system 10 may include many more connections/interfaces than those shown in FIG. 2. Thus, the elements shown in FIG. 2 are presented for ease of understanding. Also, it is contemplated that a non-AP STA 16 can be in communication and/or configured to separately communicate with more than one AP 14 and/or more than one type of AP 14. Furthermore, an AP 14 may be in communication and/or configured to separately communicate with other APs 14, which may be via wired and/or wireless communication channels.

An non-AP 16 is configured to include a preamble unit 18, which is configured to perform one or more non-AP 16 functions described herein, such as with respect to resizing or modifying the PPDU size.

Example implementations, in accordance with an embodiment, of the AP 14 and non-AP STA 16 discussed in the preceding paragraphs will now be described with reference to FIG. 3.

The AP 14 includes hardware 20 including a communication interface 22, processing circuitry 24, a processor 26, and memory 28. The communication interface 22 may be configured to communicate with any of the nodes/devices in the system 10 according to some embodiments of the present disclosure, such as with one or more other APs 14 and/or one or more non-AP STAs 16. In some embodiments, the communication interface 22 may be formed as or may include, for example, one or more radio frequency (RF) transmitters, one or more RF receivers, and/or one or more RF transceivers, and/or may be considered a radio interface. In some embodiments, the communication interface 22 may also include a wired interface.

The processing circuitry 24 may include one or more processors 26 and memory, e.g., memory 28. In addition to a processor 26 and memory 28, 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) the 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).

The AP 14 may further include software 30 stored internally in, for example, memory 28, or stored in external memory (e.g., database) accessible by the AP 14 via an external connection. 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., AP 14. The memory 28 is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software 30 may include instructions stored in memory 28 that, when executed by the processor 26 and/or preamble unit 18 causes the processing circuitry 24 and/or configures the AP 14 to perform the processes described herein with respect to the AP 14 (e.g., processes described with reference to FIG. 4, and/or any of the other figures herein). Referring still to FIG. 3, the non-AP STA 16 includes hardware 32, which may include a communication interface 34, processing circuitry 36, a processor 38, and memory 40. The communication interface 34 may be configured to communicate with one or more AP 14, such as via wireless connection 35, and/or with other elements in the system 10, according to some embodiments of the present disclosure. In some embodiments, the communication interface 34 may be formed as or may include, for example, one or more radio frequency (RF) transmitters, one or more RF receivers, and/or one or more RF transceivers, and/or may be considered a radio interface. In some embodiments, the communication interface 34 may also include a wired interface.

The processing circuitry 36 may include one or more processors 38 and memory, such as, the memory 40. Furthermore, in addition to a traditional processor and memory, the processing circuitry 36 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 38 may be configured to access (e.g., write to and/or read from) the memory 40, 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 non-AP STA 16 may further include software 42 stored internally in, for example, memory 40, or stored in external memory (e.g., database) accessible by the non-AP STA 16 via an external connection. The software 42 may be executable by the processing circuitry 36. The processing circuitry 36 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 the non-AP STA 16. The memory 40 is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software may include instructions stored in memory 40 that, when executed by the processor 38, causes the processing circuitry 36 and/or configures the non- AP STA 16 to perform the processes described herein with respect to the non-AP STA 16 (e.g., processes described with reference to FIG. 4, and/or any of the other figures herein).

In FIG. 3, the connection between the devices AP 14 and the non-AP STAs 16 is shown without explicit reference to any intermediary devices or connections. However, it should be understood that intermediary devices and/or connections may exist between these devices, although not explicitly shown.

Although FIG. 3 shows preamble unit 18, as being within a processor, it is contemplated that this element may be implemented such that a portion of the element is stored in a corresponding memory within the processing circuitry. In other words, the element may be implemented in hardware or in a combination of hardware and software within the processing circuitry. FIG. 4 is a flowchart of an example process in a first non-AP STA 16 (e.g., a wideband (WB) wireless device 16) according to one or more embodiments described herein. One or more Blocks and/or functions and/or methods performed by the first non-AP STA 16 may be performed by one or more elements of the non-AP STA 16 such as by preamble unit 18 in processing circuitry 36, memory 40, processor 38, communication interface 34, etc. according to the example process/method. The non- AP STA 16 is configured to detect (Block SI 00) narrowband interference during a listening procedure, as described herien. The non-AP STA 16 is configured to modify (Block SI 02) a PHY protocol data unit, PPDU, size for performing a subsequent listening procedure, where the modification is based on the detecting of the narrowband interference.

According to one or more embodiments, the PPDU size is modified by at least statically puncturing a plurality of resource units, RUs.

According to one or more embodiments, the PPDU size may be based at least on channel sensing.

According to one or more embodiments, the listening procedure is a backoff procedure.

According to one or more embodiments, the PPDU size may be based at least on a previous backoff procedure.

According to one or more embodiments, the PPDU size is based on a probability of a narrowband interferer continuing to transmit on a same channel and a relative difference in PPDU size after the modification.

According to one or more embodiments, the WB wireless device is a 802.11 WB wireless device.

According to one or more embodiments, the narrowband interference is based on frequency hopping.

One or more embodiments described herein provide low complexity and effective preamble puncturing schemes to deal with the presence of narrowband interference. Due to the limited time between detecting narrowband interference and performing the transmission of the punctured PPDU it is very challenging to puncture in a fully dynamic way and thus one or more embodiments described herein determines a puncturing pattern for subsequent PPDU transmissions.

For the below embodiments the narrowband interference uses a frequency hopping system, such as Bluetooth, but the teachings are equally applicable to other wireless communication protocols that may cause narrowband interference.

Embodiment 1: Static Puncturing

In a first embodiment, the WB wireless device 16, after detecting the narrowband interference, determines to statically puncture out one or more resource units (RUs). This may, at first glance, seem strange since the NBFH device (e.g., device causing the narrowband interference such as NB wireless device 17) will likely move around on different channels in accordance with an FH scheme. However, the NBFH device is likely to attempt and find the best operating channels for its frequency hopping set. For example, Bluetooth uses adaptive frequency hopping in order to tag certain channels it deems as not good for communication as “not used” for its channel hopping set and, as such, is more likely to start operating on the punctured RU.

Hence, this may lead to improved performance for both the WB device 16 and the NBFH devices. Moreover, this method allows the WB device 16 to be in control and select a suitable RU to puncture out. For example, it may be more beneficial to puncture a certain RU over another or, in the case of multiple interfering NBFH devices, puncturing out the smallest available RU may not be sufficient, but rather some set of multiple RUs is preferable to puncture out.

However, in the static puncturing, there might be a long convergence time until the NBFH device finds and operates on the punctured spectrum (depending on implementations) and furthermore, there might not be an absolute guarantee that the NBFH device will eventually converge to only that part of the bandwidth (e.g., on the punctured portion of the bandwidth that the WB device 16 selected).

Embodiment 2: Slow RU Puncturing

In another embodiment, the WB wireless device 16 punctures in a more dynamic way than Embodiment 1 so as not to entirely rely on the operation of the NBFH device, e.g., not entirely rely on the NBFH device converging on the punctured part of the bandwidth. In this case, the puncturing is still not entirely dynamic due to the previously mentioned feasibility limits. Rather, instead of dynamically changing the puncturing of the PPDU belonging to the current backoff instance, the puncturing size of the PPDU belonging to the subsequent backoff instance is dynamically changed.

FIG. 5 is a timing diagram of an example showing how the subsequent punctured PPDU pattern is chosen based on the channel sensing according to one or more embodiments of the present disclosure. For example, a wideband device is operating over a 160 MHz channel sharing the channel with a NBFH device. Initially, when the WB wireless device 16 performs EBT, it does so with the intention to transmit a full 160 MHz-wide PPDU. According to how IEEE 802. 11 bundles 20 MHz- channels, initially, during the first backoff slots, only the primary 20 MHz channel (p20) is observed (indicated by the short solid lines in FIG. 5), which is always idle.

However, PIFS (25 ps) before the start of the transmission, the device starts to observe all 20 MHz-segments of the 160 MHz channel (indicated by the long dashed line in FIG. 5). Hence, WB wireless device 16 detects the NB interference, and the backoff fails. According to Embodiment 2, instead of waiting until the NB transmission has completed, WB wireless device 16 restarts its LBT procedure, but now with a PPDU limited to the maximum available channel bandwidth that includes the primary channel which avoids the NB interference (in this case 40 MHz). This restriction allows the WB wireless device 16 to successfully complete the backoff procedure and to transmit the PPDU. Still referring to FIG. 5, in the final slot of the backoff procedure, WB wireless device 16 still senses that there is ongoing NB interference (indicated by the shorter dashed line) when the data transmission starts and thus remembers (e.g., stores data indicating this ongoing NB interference) this for the next channel access attempt. Therefore, at the start of the next channel access attempt, WB wireless device 16 immediately limits the PPDU bandwidth to 40 MHz and thus increases its probability of completing the backoff successfully.

In the timing diagram of FIG. 6, the NB interference stops during the backoff procedure. As described above, the wideband device has already prepared the 40 MHz PPDU, which is not changed. However, in the final backoff slot before the transmission, the wideband device senses (as indicated by the longer dashed line) that the NB interference has stopped, and therefore prepares a full 160 MHz PPDU in the subsequent attempt.

Using this scheme, narrowband interference that stays on the same frequency for longer periods of time can effectively be avoided. Furthermore, by reducing the size of the transmitted PPDU, the likelihood of being blocked by yet another NBFH device is reduced.

Moreover, by keeping track of successful PPDU formats in memory 40, WB wireless device 16 may determine to use this scheme in a statistical way in cases where the narrowband interference is not as persistent. Thus, depending on how much narrowband interference there is, the operating channel will be decreased (Cf. FIG. 5) by WB wireless device 16 to allow for a good chance to access the channel.

In another example, the WB wireless device 16 also takes into consideration the potential gain of using a wider channel bandwidth, as well as the likelihood of there being NB interference in the channel. For example, it may be beneficial for the WD wireless device 16 to try and wait out the interference if it means that a much wider channel bandwidth may be employed. In other cases, it may also be beneficial for the WB wireless device 16 to try a wider bandwidth PPDU first and then restart the UBT after detecting the NB interference.

In another example, the WB wireless device 16 might also want to take into consideration what type of traffic is being delivered. For example, by choosing a reduced PPDU format and applying a puncturing pattern, the likelihood of successful channel access increases but the overall data that may be transmitted in the PPDU gets reduced. Thus, it may be more beneficial for latency sensitive applications (e.g., software applications operating at WB wireless device 16) to choose a more stringent PPDU format to try and guarantee channel access whilst applications relying more on high throughput might want to choose to wait out the narrowband interference.

Below, some performance curves of this scheme in a simulation scenario are described where there are 3 Wi-Fi APs using non-overlapping 160 MHz channels to communicate to 3 Wi-Fi STAs (e.g., WB wireless device 16). The Wi-Fi nodes are being interfered by 1 to 6 Bluetooth links transmitting 1280B of data with a periodicity of 20 milliseconds. In the case of the example shown in the graph of FIG. 7, the Wi-Fi STAs perform FTP file downloads, thus, the key performance indicator measured is the mean file download delay. In this case, using an idealistic fully dynamic puncturing shows significant gains over the no-puncturing case, whereas the slow puncturing has only marginal to no gain. For this traffic assumption, raw throughput is important. However, the implementation of slow puncturing in the simulation does not effectively use the available spectrum as it only punctures to valid RU sizes. For example, a 160 MHz channel may only puncture to an 80/40/20 MHz transmission and as such a lot of valuable resources are left unused. More effective implementations making use of the mRUs introduced in 1 Ibe (e.g., 802. 1 Ibe) or assignments of RUs to multiple users may achieve better spectral efficiency and thus also increase the gain in the FTP case.

In contrast, the graph of FIG. 8 shows the results if the FTP traffic is replaced by a cloud gaming traffic, i.e., with high-rate video downlink (30MB/s mean) and small but high-frequent control traffic uplink (15ms inter-frame duration). As a key performance indicator, a worst-case round-trip time is used (i.e., the sum of the 99th percentiles of the uplink- and downlink delay), corresponding to the gaming delay observed by the user. From the results, it becomes visible that while the ideal fully dynamic puncturing still gives the best performance, there is already a significant gain in using the slowly adaptive puncturing in comparison to the no-puncturing case. This result can be explained by the fact that for this latency-sensitive traffic, reducing the channel access time is important, whereas the maximum throughput is secondary, especially for the small control uplink frames.

Therefore, one or more embodiments described herein are beneficial for latency-critical applications where the reduction of the time to access the channel in the presence of narrowband interference is important.

Additional Examples

Within the present disclosure, frequency hopping devices have been assumed to be the narrowband interferer. However, it should be noted that teachings described herein may also be applied to deal with narrowband interference from technologies that remain on the same frequency channel, or do not change their operating channels very frequently.

Furthermore, in some scenarios the narrowband interferer could be any technology working on a narrower band than the wideband device. For example, if there are one or more 20 MHz Wi-Fi APs operating on separate channels within a larger 160 MHz channel, the wideband wireless devices 16 could also make use of the present disclosure to find suitable PPDU formats for subsequent channel attempts.

Therefore, according to one or more embodiments, a wideband transmitter may achieve much better channel access delay and throughput in cases when the medium is shared with narrowband devices when compared to existing coexistence schemes. Some Non-Limiting Examples

1. A method in a wideband wireless device 16 for improving its channel access delay or throughput in an environment shared with narrowband interferers, the method includes: starting a backoff procedure to access the wireless medium, detecting narrowband interference that forces the wireless device to stop the backoff procedure, selecting a PPDU size for a subsequent backoff procedure based on the narrowband interference frequency usage.

2. The method of Example 1, where the wireless device selects the same PPDU format as what cleared the previous backoff attempt.

3. The method of Example 2, where the decision to select the same PPDU format is based on sensing the narrowband interference up until the transmission occurs.

4. The method of Example 1, where the WB wireless device 16 stores one or more previously successful PPDU formats in memory and chooses the next PPDU size based on statistics.

5. The method of Example 1, where the WB wireless device 16 statically chooses a punctured PPDU format.

6. The method of any of Examples 1-5, where the determination of the next PPDU size considers the probability of the NB interferer continuing to transmit on the same channel and the relative difference in PPDU size.

7. The method of any of Examples 1-6, where the WB wireless device 16 is an 802.11 STA.

8. The method of Example 6, where the transmission size after puncturing matches a valid RU size.

9. The method of any one of Examples 1-8, where the narrowband interferer (e.g., NB wireless device 17) is using frequency hopping.

As will be appreciated by one of skill in the art, the concepts described herein may be embodied as a method, data processing system, computer program product and/or computer storage media storing an executable computer program. Accordingly, the concepts described herein may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects all generally referred to herein as a “circuit” or “module.” Any process, step, action and/or functionality described herein may be performed by, and/or associated to, a corresponding module, which may be implemented in software and/or firmware and/or hardware. Furthermore, the disclosure may take the form of a computer program product on a tangible computer usable storage medium having computer program code embodied in the medium that can be executed by a computer. Any suitable tangible computer readable medium may be utilized including hard disks, CD-ROMs, electronic storage devices, optical storage devices, or magnetic storage devices. Some embodiments are described herein with reference to flowchart illustrations and/or block diagrams of methods, systems and computer program products. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer (to thereby create a special purpose computer), special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

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

The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.

It is to be understood that the functions/acts noted in the blocks may occur out of the order noted in the operational illustrations. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality/acts involved. Although some of the diagrams include arrows on communication paths to show a primary direction of communication, it is to be understood that communication may occur in the opposite direction to the depicted arrows.

Computer program code for carrying out operations of the concepts described herein may be written in an object oriented programming language such as Python, Java® or C++. However, the computer program code for carrying out operations of the disclosure may also be written in conventional procedural programming languages, such as the "C" programming language. The program code may execute entirely on the user's computer, partly on the user's computer, as a standalone software package, partly on the user's computer and partly on a remote computer or entirel y on the remote computer. In the latter scenario, the remote computer may be connected to the user's computer through a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). Many different embodiments have been disclosed herein, in connection with the above description and the drawings. It will be understood that it would be unduly repetitious and obfuscating to literally describe and illustrate every combination and subcombination of these embodiments. Accordingly, all embodiments can be combined in any way and/or combination, and the present specification, including the drawings, shall be construed to constitute a complete written description of all combinations and subcombinations of the embodiments described herein, and of the manner and process of making and using them, and shall support claims to any such combination or subcombination.

It will be appreciated by persons skilled in the art that the embodiments described herein are not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings.

Embodiments:

Embodiment Al . A wideband, WB, wireless device configured to: detect narrowband interference during a listening procedure; and modify a PHY protocol data unit, PPDU, size for performing a subsequent listening procedure, the modification is based on the detecting of the narrowband interference.

Embodiment A2. The WB wireless device of Embodiment Al, wherein the PPDU size is modified by at least statically puncturing a plurality of resource units, RUs.

Embodiment A3. The WB wireless device of any one of Embodiments A1-A2, wherein the PPDU size may be based at least on channel sensing.

Embodiment A4. The WB wireless device of any one of Embodiments A1-A3, wherein the listening procedure is a backoff procedure.

Embodiment A5. The WB wireless device of Embodiment A4, wherein the PPDU size may be based at least on a previous backoff procedure.

Embodiment A6. The WB wireless device of any one of Embodiments A1-A5, wherein the PPDU size is based on a probability of a narrowband interferer continuing to transmit on a same channel and a relative difference in PPDU size after the modification. Embodiment A7. The WB wireless device of any one of Embodiments A1-A6, wherein the WB wireless device is a 802.11 WB wireless device.

Embodiment A8. The WB wireless device of any one of Embodiments A1-A7, wherein the narrowband interference is based on frequency hopping.

Embodiment Bl. A method implemented by a wideband, WB, wireless device, the method comprising: detecting narrowband interference during a listening procedure; and modifying a PHY protocol data unit, PPDU, size for performing a subsequent listening procedure, the modification is based on the detecting of the narrowband interference.

Embodiment B2. The method of Embodiment Bl, wherein the PPDU size is modified by at least statically puncturing a plurality of resource units, RUs.

Embodiment B3. The method of any one of Embodiments Bl - B2, wherein the PPDU size may be based at least on channel sensing.

Embodiment B4. The method of any one of Embodiments Bl- B3, wherein the listening procedure is a backoff procedure.

Embodiment B5. The method of Embodiment B4, wherein the PPDU size may be based at least on a previous backoff procedure.

Embodiment B6. The method of any one of Embodiments Bl- B5, wherein the PPDU size is based on a probability of a narrowband interferer continuing to transmit on a same channel and a relative difference in PPDU size after the modification.

Embodiment B7. The method of any one of Embodiments Bl - B6, wherein the WB wireless device is a 802.11 WB wireless device.

Embodiment B8. The method of any one of Embodiments Bl- B7, wherein the narrowband interference is based on frequency hopping.

Claims

1. A wideband, WB, wireless device (16) configured to: operate communication according to a listen-before-talk, LBT, procedure over a multitude of resource units, RUs, forming a primary channel and one or more secondary channels to transmit a PHY protocol data unit, PPDU, wherein a PPDU bandwidth is equal to frequencies covered by the RUs for LBT procedure; modify (S136), when narrowband, NB, interference is present in a first secondary channel during a first LBT procedure, the PPDU bandwidth by removing one or more RUs in the first secondary channel; perform a subsequent second LBT procedure for the modified PPDU bandwidth; and transmit a PPDU with the modified PPDU bandwidth after the second LBT procedure.

2. The WB wireless device (16) of claim 1, further configured to: restore PPDU bandwidth when no NB interferer is present in the first secondary channel at a third LBT procedure subsequent to the second LBT procedure.

3. The WB wireless device (16) of claim 2, wherein a minimum time between the second LBT procedure and the third LBT procedure is set to a first value for latence sensitive traffic and to a second value for traffic not indicated as latentcy sensitive traffic, wherein the first value is larger than the second value.

4. The WB wireless device (16) of any one of claims 1-3, wherein the LBT procedures are backoff procedures.

5. The WB wireless device (16) of any one of claims 1-4, being an IEEE 802.11 WB wireless device.

6. The WB wireless device (16) of claim 5, wherein the removing of RUs comprises removing RUs corresponding to an IEEE 802.11 20 MHz channel.

7. The WB wireless device (16) of any one of claims 1-6, wherein the narrowband interference is based on frequency hopping.

8. A method for a wideband, WB, wireless device (16), the method comprising operating communication according to a listen-before-talk, LBT, procedure over a multitude of resource units, RUs, forming a primary channel and one or more secondary channels to transmit a PHY protocol data unit, PPDU, wherein a PPDU bandwidth is equal to frequencies covered by the RUs for LBT procedure; modifying (S136), when narrowband, NB, interference is present in a first secondary channel during a first LBT procedure, the PPDU bandwidth by removing one or more RUs in the first secondary channel; performing a subsequent second LBT procedure for the modified PPDU bandwidth; and transmitting a PPDU with the modified PPDU bandwidth after the second LBT procedure.

9. The method of claim 8, further comprising restoring PPDU bandwidth when no NB interferer is present in the first secondary channel at a third LBT procedure subsequent to the second LBT procedure.

10. The method of claim 9, wherein a minimum time between the second LBT procedure and the third LBT procedure is set to a first value for latence sensitive traffic and to a second value for traffic not indicated as latentcy sensitive traffic, wherein the first value is larger than the second value.

11. The method of any one of claims 8-10, wherein the LBT procedures are backoff procedures.

12. The method of any one of claims 8-11, wherein the WB wireless device (16) is an IEEE 802.11 WB wireless device.

13. The method of claim 12, wherein the removing of RUs comprises removing RUs corresponding to an IEEE 802.11 20 MHz channel.

14. The method of any one of claims 8-13, wherein the narrowband interference is based on frequency hopping.