Adaptive listen-before-talk for wideband systems

Abstract

A method is performed in a wireless device, WD, and / or network node) in a system, the WD and / or network node being configured to perform spectrum sharing associated with one or more adaptive Listen-Before-Talk (LBT) operations. The method includes detecting a presence of multiple frequency-hopping WDs with high duty cycle and adapting one or more parameters of the one or more LBT operations based on the detected presence, the one or more parameters determining aggressiveness of channel access.

Description

[0001] ADAPTIVE LISTEN-BEFORE-TALK FOR WIDEBAND SYSTEMS

[0002] FIELD

[0003] The present disclosure relates to wireless communications, and in particular, to Listen- Before-Talk (LBT), energy detection threshold, coexistence, interference, Wi-Fi, Bluetooth, narrow-band frequency hopping, spectrum sharing, etc.

[0004] INTRODUCTION

[0005] Some wireless communication systems, such as Wi-Fi systems, may operate in licenseexempt bands. Wi-Fi, also known as Wireless Local Area Network (WLAN), is a technology that currently mainly operates in the 2.4 GHz, the 5 GHz, and the 6 GHz bands. When operating in license-exempt bands, e.g., the 2.4 GHz band, the 5 GHz band, or the 6 GHz band, spectrum sharing mechanisms are typically required unless the transmissions are limited to using a very low power. The two most commonly used spectrum sharing mechanisms are: (i) LBT, typically implemented by carrier sense multiple access with collision avoidance (CSMA / CA); and (ii) frequency hopping (FH).

[0006] CSMA / CA-based LBT works 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 ("Carrier Sense"). 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 defer from transmission. To reduce the probability that two or more devices transmit at the same time, the channel sensing duration is randomized, and the range of the duration is adapted based on recent transmission success rates ("Collision Avoidance"). CSMA / CA-based LBT may be used by different flavors of Electrical and Electronics Engineers (IEEE) 802.11, commonly referred to as Wi-Fi. It is also employed by standards developed by the Third Generation Partnership Project (3GPP) operating in the 5 GHz band, e.g., new radio unlicensed (NR-U).

[0007] If instead FH is used, the spectrum sharing is based on only using a relatively small part of the band for a relatively small fraction of the total time, leaving room for other transmissions. FH is the approach used by, for example, Bluetooth.

[0008] Whether to employ CSMA / CA-based LBT or FH may not be apparent, but typically LBT is the preferred approach if the used channel bandwidth is relatively large, e.g., 20 MHz or more, and the required usage of the channel is very dynamic with a lot of variance. However, FH is well suited for narrowband systems where the occupied bandwidth is much less (in the order of few MHz) and a predictable, deterministic channel usage is required. Although both CSMA / CA-based LBT and FH can be viewed as effective spectrum sharing mechanisms, both typically only work well if all devices are using the same spectrum sharing mechanism. That is, if all devices either apply LBT or use FH, things work well. However, if some devices use LBT whereas others use FH, the system may not be working properly. As one example, a wideband system using LBT may detect a narrowband transmission and defer from transmitting although such a transmission would have been successful without causing any 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 a transmission that potentially can result in harmful interference to the narrowband system.

[0009] Currently, the above situation is present in the 2.4 GHz industrial, scientific, and medical (ISM) band where Wi-Fi uses CSMA / CA-based LBT, whereas Bluetooth uses FH. To allow for better coexistence between the two standards, Bluetooth has developed support for adaptive FH (AFH), which means that the Bluetooth devices identify channels with high interference, and then adapt the hopping pattern used for FH such that these channels are no longer used. Furthermore, as the assumption is that the interference originates from Wi-Fi, all frequencies coinciding with the overlapping 20 MHz Wi-Fi channel are also removed from the hopping pattern. Eventually, Bluetooth may vacate the spectrum used by Wi-Fi. In Bluetooth Low Energy (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 they will not overlap with the three most commonly used Wi-Fi channels (Wi-Fi Channels 1, 6 and 11).

[0010] AFH may be an effective coexistence mechanism in some cases, but it has the limitation that it is rather slow to adapt. By necessity, it takes some time to determine whether a frequency channel should be considered as occupied by another system and therefore should not be used, and also to determine when it is no longer occupied so that it should be used again. How long this takes may also depend on how much the channel is used, and it can be expected that if a channel is only used, say, 10% of the time, many FH transmissions may be needed in order to determine that in fact the channel is occupied. During this time, the impact on the wideband system may be non-negligible.

[0011] To enhance the coexistence between a FH system and a wideband system using CSMA / CA-based LBT it is proposed to let the FH system use a simplified form of LBT, denoted as frequency -hopping LBT (FH-LBT) in the following. Specifically, for the FH system, before transmitting a narrow band signal on a new frequency, it is first checked whether the narrowband channel is idle or busy. If the channel is idle, the transmission is started, but if the channel is found to be busy, the transmission on this channel is skipped, and the transmitter waits for the next attempt on the next channel according to the frequency hopping pattern. In comparison to the CSMA / CA-based LBT, the FH-LBT does not randomize or adapt the sensing duration, as the "Collision Avoidance" part is already given by the random selection of the narrow band channel.

[0012] FH-LBT can be combined with AFH, i.e., the system remembers that channels have been sensed as occupied regularly, and then removes them completely from the hopping pattern. Adding FH-LBT to AFH speeds up the convergence of AFH to unoccupied spectrum, as not only reception errors trigger a removal of a frequency from the hopping pattern. Furthermore, even before convergence, the FH system is more careful not to interfere with the wideband system as it backs off its transmission if it detects the channel as occupied. Of course, the time it takes until the FH-LBT converges introduces additional delay to the narrowband system because it will skip transmission opportunities every time the FH-LBT detects a channel that is still in the hopping pattern as busy.

[0013] In some cases, if multiple wideband systems occupy the complete available spectrum, all non-overlapping available wideband channels may be used. More specifically, the FH-LBT may detect all channels always as occupied and fail to deliver the given load. Further, an adaptive LBT operation for the FH system, which adapts the sensitivity of the LBT depending on the spectrum usage, may be employed, where the FH-LBT may ignore wideband transmissions if the FH is limited to a smaller amount of the spectrum, thereby balancing out the probability for channel access.

[0014] A similar problem exists for a wideband system attempting to access the channel if multiple FH systems (with or without LBT) with sufficiently high load are present.

[0015] FIG. 1 shows an exemplary spectrum sharing situation at low narrowband load. The available spectrum, which is shared between an LBT-FH and a wideband system, may be 80MHz. The wideband system channel bandwidth may be 20MHz, and it only uses the lowest of the four 20MHz channels. At the same time, one FH link is active, spreading out its frame exchanges over the whole 80MHz by using 2MHz at any given time.

[0016] In the beginning, only the FH link is active; hence, the LBT detects the channel as idle, and the frame exchange can take place as planned. At the next hopping interval, the FH link (pseudo-)randomly selects another narrowband channel and repeats the operation. As the operation is spread over the whole spectrum, the probability is high that the wideband link's LBT detects its 20MHz channel as idle (essentially a bit higher than 1 / 4), hence also the wideband link can start the transmission without significant delay. Once the wideband link is active, the probability is very low that the FH link jumps into the 20MHz spectrum exactly at the interframe times. Hence, wideband is blocking this portion of the spectrum, and the FH link's LBT will detect it as busy, which must be handled, for example, by quickly selecting another part of the spectrum to transmit. Therefore, the spectrum is shared by the two technologies.

[0017] FIG. 2 shows an exemplary spectrum sharing situation at high narrowband load. Instead of a single FH-link, in FIG. 2, 6 links (different shades of gray) are active at the same time, all with a significant duty cycle. As seen from the wideband link, at no time will the clear channel assessment (CCA) detect the channel as idle during the LBT process, as always at least one FH- link is using a fragment of the 20MHz wideband channel. Hence, the wideband system is blocked from accessing the channel.

[0018] The blocking probability may depend on:

[0019] (1) the fraction of the complete spectrum that the wideband system is using.

[0020] (2) the number of FH-links and their duty cycle.

[0021] To evaluate the blocking probability a simulation campaign may be performed. Assuming realistic parameters of the wideband system and the FH-links that share 480MHz of spectrum, the wideband system may have either 20MHz, 40MHz, 80MHz, or 160MHz of spectrum. Further, the FH system may use 230 channels where 1MHz are allocated evenly spaced in the 480MHz. There may be 1 to 50 FH active links, with a duty cycle of 1% to 80%.

[0022] FIG. 3 shows an example channel access delay 99-percentile for a wideband link interfered with by FH-links. More specifically, four plots are shown, for the four different assumed wideband bandwidths, the 99-percentile of the channel access delay. A delay of more than 50ms may be assumed to correspond to a perceivable impact to the wideband system. The graphs show the lines that limit the areas where the wideband system has a 99-percentile channel access delay of less than 10ms / 20ms / 50ms / 100ms.

[0023] Even if only a 20MHz fraction of the 480MHz is accessed by the wideband system, loads above approximately 50% and more than 30 active links result in channel access delays of more than 20ms. Once the bandwidth requirement of the wideband system grows, the probability of a blocked channel increases. This becomes visible as the 10 / 20 / 50 / 100ms lines shift to the origin corner of the graphs. In the case of 160MHz channels, only 10 FH links with high duty cycle above 60% lead to a channel access delay of ~100ms; similar values are observed with 40 FH links and a duty cycle above 20%.

[0024] It has to be noted that this blocking will not occur if the wideband link shares the spectrum with another wideband link, that also adheres to the specification of LBT and thus uses a contention-based protocol. In this case, the other wideband link's channel usage in time is limited by the maximum allowed transmit duration. Hence, the first wideband link will sense an idle channel at least after this maximum duration, in contrast to the situation as described above.

[0025] Furthermore, it must be observed that this blocking is not limited to the case of a single wideband link and multiple NBFH links. It might very well also occur if a wideband link, using CSMA / CA as described above, aggregates multiple parts of the spectrum which are also occupied by other wideband links using CSMA / CA. FIG. 10 illustrates an example where a wideband channel is blocked by other wideband users. Here, different parts of the spectrum (e.g., 20 MHz each) are used by four different wideband systems. The fifth wideband system attempts to access the full spectrum (80 MHz to continue the example), but is unable to do so as at any time it is blocked by at least one of the other systems, although each of the systems leave more than enough idle time.

[0026] SUMMARY

[0027] Aspects of the invention are given by the appended independent claims, and embodiments thereof are given by the appended dependent claims.

[0028] Some embodiments advantageously provide methods, systems, and apparatuses for an adaptive LBT operation and / or method for wideband systems. The operation may be based on the detection of channel blocking for an unknown (from the listening entity's point of view and knowledge) duration, e.g., by multiple narrowband frequency-hopping links. In some embodiments, on or both of the following steps may be performed:

[0029] (1) Using its clear channel assessment (CCA), a wireless device (WD) (e.g., wideband device) detects the channel as continuously occupied by energy for a duration that is larger than the maximum channel occupancy time allowed for wideband. The WD concludes that a situation as given in the examples above is present, and it is blocked from accessing the channel, e.g., by the multiple narrowband FH links.

[0030] (2) As a mitigation, the wideband device slowly increases its energy-detection threshold (EDT), thereby becoming less sensitive. Eventually, the CCA may identify the channel as idle, such that the wideband device is allowed to transmit.

[0031] After a successful transmission, the EDT level of the wideband device is reset to the default value.

[0032] In addition, the wideband device may also use other channel statistics before raising the EDT, especially the variance of the measured energy over time.

[0033] The embodiments of the present disclosure may mitigate the impact on channel blocking for a wideband device caused by other users of the spectrum, e.g., the multiple frequency- hopping high duty-cycle links for a wideband device as of example given above. As the wideband device can detect the presence of the blocking situation and distinguish this situation from the presence of other, probably higher-priority wideband devices, it becomes possible for the wideband device to react appropriately. By increasing the LBT EDT as a reaction, eventually the wideband link will be able to transmit despite the other users and as such it will never be completely blocked out of channel access.

[0034] BRIEF DESCRIPTION OF THE DRAWINGS

[0035] 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:

[0036] FIG. 1 shows an exemplary spectrum sharing situation at low narrowband load;

[0037] FIG. 2 shows an exemplary spectrum sharing situation at high narrowband load;

[0038] FIG. 3 shows an example channel access delay 99-percentile for a wideband link interfered with by FH-links;

[0039] FIG. 4 is a schematic diagram of an example network architecture illustrating a communication system according to principles disclosed herein;

[0040] FIG. 5 is a block diagram of a network node in communication with a WD over a wireless connection according to some embodiments of the present disclosure;

[0041] FIG. 6 is a flowchart of an example process in a WD according to some embodiments of the present disclosure;

[0042] FIG. 7 is a flowchart of an example process in a WD according to some embodiments of the present disclosure;

[0043] FIG. 8 shows example transmissions in the lower 20MHz segment, and also the exemplary received energy and the EDT of a WD according to some embodiments of the present disclosure; and

[0044] FIG. 9 shows an adaptive EDT that allows WD 22 to access the medium after having boosted twice according to some embodiments of the present disclosure.

[0045] FIG. 10 illustrates an example where a wideband channel is blocked by other wideband users.

[0046] DETAILED DESCRIPTION

[0047] Before describing in detail exemplary embodiments, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to an adaptive LBT operation or method for wideband systems. 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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. Referring again to Wi-Fi or WLAN, there are specifications regulating an access points' or mobile terminals' physical (PHY) layer, medium access layer (MAC) layer and other aspects in order to secure 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 license-exempt 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.

[0052] In some embodiments, the term “network node” is used and may comprise, or be, an “access point” or “AP”. 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.

[0053] In some embodiments, the non-limiting term “device” or wireless device (WD) is used to describe a wideband device and / or user equipment (UE) that may be used to implement some embodiments of the present disclosure. In some embodiments, the WD 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.

[0054] 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, e.g., a first STA and, e.g., a second STA. For DL communication, the first STA may be the transmitter, and the second STA may be the receiver. For UL communication, the transmitter may be the second STA, and the receiver may be the first STA. In some embodiments, the first STA may be an AP or non-AP STA, and the second STA may be an AP or a non-AP STA. Thus, the WD 22 may act as an AP STA or a non-AP STA.

[0055] Note also that some embodiments of the present disclosure may be supported by an Institute of 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 (e.g., standard documents). In addition, all the terms disclosed in the present document may be described by the above standard documents.

[0056] 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 (WCDMA), 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 first STA, second STA, transmitting STA, receiving 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.

[0057] In some embodiments, the term “transmission signal quality condition” is used and may refer to transmit (TX) signal quality requirements, such as in terms of EVM of the transmitted signal. A maximum TX power may be limited by the transmit signal quality requirements.

[0058] 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.

[0059] Referring again to the drawing figures, in which like elements are referred to by like reference numerals, there is shown in FIG. 4 a schematic diagram of a communication system 10 (e.g., wideband system), according to an embodiment, that may support standards such as Wi-Fi, Bluetooth, LTE and / or NR (5G), which may comprise an access network 12, such as a radio access network, and a core network 14. The access network 12 comprises a plurality of network nodes 16a, 16b, 16c (referred to collectively as network nodes 16), such as APs or other wireless access points, each defining a corresponding coverage area 18a, 18b, 18c (referred to collectively as coverage areas 18). Each network node 16a, 16b, 16c is connectable to the core network 14 over a wired or wireless connection 20. A first WD 22a located in coverage area 18a is configured to wirelessly connect to, or be paged by, the corresponding network node 16a. A second WD 22b in coverage area 18b is wirelessly connectable to the corresponding network node 16b. While a plurality of WDs 22a, 22b (collectively referred to as WDs 22) are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole WD is in the coverage area or where a sole WD is connecting to the corresponding network node 16. Note that although only two WDs 22 and three network nodes 16 are shown for convenience, the communication system may include many more WDs 22 and network nodes 16.

[0060] Also, it is contemplated that a WD 22 can be in simultaneous communication and / or configured to separately communicate with more than one network node 16 and more than one type of network node 16. For example, a WD 22 can have dual connectivity with a network node 16 that supports a communication technology and the same or a different network node 16 that supports another communication technology.

[0061] A network node 16 is configured to include a node management unit 24 which is configured to perform any step and / or task and / or process and / or method and / or feature described in the present disclosure, e.g., network node functions. A WD 22 is configured to include a WD management unit 26 which is configured to perform any step and / or task and / or process and / or method and / or feature described in the present disclosure, e.g., WD functions.

[0062] Example implementations, in accordance with an embodiment, of the WD 22 and network node 16 discussed in the preceding paragraphs will now be described with reference to FIG. 5.

[0063] The communication system 10 includes a network node 16 provided in a communication system 10 and includes hardware 28 enabling it to communicate with the WD 22. The hardware 28 may include a radio interface 30 for setting up and maintaining at least a wireless connection 32 with a WD 22 located in a coverage area 18 served by the network node 16. The radio interface 30 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 radio interface 30 includes an array of antennas 34 to radiate and receive signal(s) carrying electromagnetic waves. The hardware 28 may also include a communication interface 31 for setting up and maintaining wireless / wired connection with other network nodes 16 and / or WDs 22. The communication interface 31 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 communication interface 31 may also include an array of antennas to radiate and receive signal(s) carrying electromagnetic waves.

[0064] In the embodiment shown, the hardware 28 of the network node 16 further includes processing circuitry 36. The processing circuitry 36 may include a processor 38 and a memory 40. In particular, in addition to or instead of a processor, such as a central processing unit, 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 network node 16 further has software 42 stored internally in, for example, memory 40, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the network node 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 network node 16. Processor 38 corresponds to one or more processors 38 for performing network node 16 functions described herein. The memory 40 is configured to store data, programmatic software code and / or other information described herein. In some embodiments, the software 42 may include instructions that, when executed by the processor 38 and / or processing circuitry 36, causes the processor 38 and / or processing circuitry 36 to perform the processes described herein with respect to network node 16. For example, processing circuitry 36 of the network node 16 may include node management unit 24 which is configured to perform any step and / or task and / or process and / or method and / or feature described in the present disclosure, e.g., network node functions.

[0065] The communication system 10 further includes the WD 22 already referred to. The WD 22 may have hardware 44 that may include a radio interface 46 configured to set up and maintain a wireless connection 32 with a network node 16 serving a coverage area 18 in which the WD 22 is currently located. The radio interface 46 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 radio interface 46 includes an array of antennas 48 to radiate and receive signal(s) carrying electromagnetic waves. The hardware 44 may also include a communication interface for setting up and maintaining wireless / wired connection with other WDs 22 and / or network nodes 16. The communication interface 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 communication interface may also include an array of antennas to radiate and receive signal(s) carrying electromagnetic waves.

[0066] The hardware 44 of the WD 22 further includes processing circuitry 50. The processing circuitry 50 may include a processor 52 and memory 54. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 50 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 52 may be configured to access (e.g., write to and / or read from) memory 54, 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).

[0067] Thus, the WD 22 may further comprise software 56, which is stored in, for example, memory 54 at the WD 22, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the WD 22. The software 56 may be executable by the processing circuitry 50. The software 56 may include a client application 58. The client application 58 may be operable to provide a service to a human or non-human user via the WD 22.

[0068] The processing circuitry 50 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 WD 22. The processor 52 corresponds to one or more processors 52 for performing WD 22 functions described herein. The WD 22 includes memory 54 that is configured to store data, programmatic software code and / or other information described herein. In some embodiments, the software 56 and / or the client application 58 may include instructions that, when executed by the processor 52 and / or processing circuitry 50, causes the processor 52 and / or processing circuitry 50 to perform the processes described herein with respect to WD 22. For example, the processing circuitry 50 of the WD 22 may include WD management unit 26 which is configured to perform any step and / or task and / or process and / or method and / or feature described in the present disclosure, e.g., WD functions.

[0069] In some embodiments, the inner workings of the network node 16 and WD 22 may be as shown in FIG. 5 and independently, the surrounding network topology may be that of FIG. 4.

[0070] The wireless connection 32 between the WD 22 and the network node 16 is in accordance with the teachings of the embodiments described throughout this disclosure. More precisely, the teachings of some of these embodiments may improve the data rate, latency, and / or power consumption and thereby provide benefits such as reduced user waiting time, relaxed restriction on file size, better responsiveness, extended battery lifetime, etc. In some embodiments, a measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve.

[0071] Although FIGS. 4 and 5 show various “units” such as node management unit 24 and WD management unit 26 as being within a respective processor, it is contemplated that these units may be implemented such that a portion of the unit is stored in a corresponding memory within the processing circuitry. In other words, the units may be implemented in hardware or in a combination of hardware and software within the processing circuitry. FIG. 6 is a flowchart of an example process in a WD 22. One or more blocks described herein may be performed by one or more elements of network node 16 such as by one or more of processing circuitry 50 (including the WD management unit 26), processor 52, and / or radio interface 46. WD 22 such as via processing circuitry 50 and / or processor 52 and / or radio interface 46 is configured to detect (Block SI 00) a presence of multiple frequency -hopping WDs 22 with high duty cycle and adapt (Block SI 02) one or more parameters of the one or more LBT operations based on the detected presence, the one or more parameters determining aggressiveness of channel access.

[0072] In some embodiments, one or more of: (A) the detection of the multiple frequencyhopping WDs 22 with high duty cycle is performed by recognizing energy without a gap that exceeds a predetermined gap threshold on the channel for a predetermined duration; (B) the gap exceeds the predetermined gap threshold if its duration is equal or longer to a gap duration required between two wideband channel occupancies; and (C) the predetermined duration is the maximum channel occupancy time of the system.

[0073] In some other embodiments, one or more of: (A) the adaptation of is performed by increasing an energy detection threshold (EDT) value; (B) the EDT value is increased while the channel stays busy; and (C) the increase of the EDT value cannot exceed a currently sensed energy level.

[0074] In some embodiments, one or both of: (A) the adaptation is applied only to a predetermined frequency part of an available bandwidth; and (B) the one or more parameters are reset to a default value after a successful channel access attempt.

[0075] In some embodiments, the system 10 is a wideband system, and the WD 22 is a wideband device.

[0076] FIG. 7 is a flowchart of an example process in a network node 16. One or more blocks described herein may be performed by one or more elements of network node 16 such as by one or more of processing circuitry 36 (including the node management unit 24), processor 38, and / or radio interface 30. Network node 16 such as via processing circuitry 36 and / or processor 38 and / or radio interface 30 is configured to detect (Block S104) a presence of multiple frequency -hopping WDs 22 with high duty cycle and adapt (Block SI 06) one or more parameters of the one or more LBT operations based on the detected presence, the one or more parameters determining aggressiveness of channel access. In the context of non-AP STA and AP STA elucidated above, the network node 16 typically acts as an AP STA.

[0077] In some embodiments, one or more of: (A) the detection of the multiple frequencyhopping WDs 22 with high duty cycle is performed by recognizing energy without a gap that exceeds a predetermined gap threshold on the channel for a predetermined duration; (B) the gap exceeds the predetermined gap threshold if its duration is equal or longer to a gap duration required between two wideband channel occupancies; and (C) the predetermined duration is the maximum channel occupancy time of the system.

[0078] In some other embodiments, one or more of: (A) the adaptation of is performed by increasing an energy detection threshold (EDT) value; (B) the EDT value is increased while the channel stays busy; and (C) the increase of the EDT value cannot exceed a currently sensed energy level.

[0079] In some embodiments, one or both of: (A) the adaptation is applied only to a predetermined frequency part of an available bandwidth; and (B) the one or more parameters are reset to a default value after a successful channel access attempt.

[0080] In some other embodiments, one or more of the system 10 is a wideband system, the network node 16 is wideband device, and the WDs 22 are other wideband devices.

[0081] Having described the general process flow of arrangements of the disclosure and having provided examples of hardware and software arrangements for implementing the processes and functions of the disclosure, the sections below provide details and examples of arrangements for an adaptive LBT operation or method for wideband systems.

[0082] The following are nonlimiting example embodiments:

[0083] 1. A spectrum sharing mechanism for a wideband device employing listen-before-talk is described, where the WD 22 detects the presence of multiple frequency-hopping devices with high duty cycle (e.g., above a predetermined threshold) and adapts at least one of the parameters of the listen-before-talk determining the aggressiveness of the channel access.

[0084] 2. As in Example 1, where the detection of the multiple frequency -hopping devices with high duty cycle is performed by recognizing energy without a significant gap on the channel for a certain duration.

[0085] 3. As in Example 2, where a gap is significant if its duration is equal or longer to the gap duration required between two wideband channel occupancies.

[0086] 4. As in Example 2, where the certain duration is the maximum channel occupancy time of the wideband system.

[0087] 5. As in Example 1, where the adaptation of the listen-before-talk parameter is done by increasing the energy detection threshold value.

[0088] 6. As in Example 1, where the energy detection threshold value is increased while the channel stays busy. 7. As in any one of Examples 5 and 6, where the increase of the energy detection threshold cannot exceed the currently sensed energy level.

[0089] 8. As in any of Examples 1-7, where the adaptation of the listen-before-talk-parameters are applied only to a certain frequency part of the available bandwidth.

[0090] 9. As in any of Examples 1-8, where the at least one parameter of the listen-before-talk is reset to its default value after a successful channel access attempt.

[0091] FIG. 8 is a graph showing the transmissions in the lower 20MHz segment, and also the exemplary received energy and the EDT of WD 22. More specifically, FIG. 8 shows an exemplary energy detection situation based on the case shown in FIG. 2. However, in FIG. 8, a static EDT is exceeded by the NB transmissions. As the received energy may be always above the EDT, the CCA may report the channel always as busy and the already described blocking of the channel occurs. However, if the methods of the present disclosure are enabled, then the behavior of WDs 22 change as exemplified in the graph of FIG. 9 which is also an exemplary energy detection situation based on the case shown in FIG. 2. More specifically, FIG. 9 shows an adaptive EDT that allows WD 22 to access the medium after having been boosted twice. After a certain duration of being blocked, WD 22 starts to increase the EDT level. In this example, the increasing of the EDT level happens in consecutive steps. After two increases, also the situation on the channel changes, as one FH transmission stops and another one starts. In contrast to other situations, by the increased EDT, the CCA may now identify the channel as idle, and the wideband transmission starts.

[0092] This wideband transmission may also be detected (vice-versa) by all other FH links that hop into this part of the spectrum; therefore, they (e.g., the FHP links) may refrain from accessing the channel and not interfere with the ongoing wideband transmission.

[0093] To reduce the impact of the wideband transmission to an already active transmission once the boosting of the EDT is in progress, the increase of the EDT may be limited by the currently sensed energy. In this way, in some embodiments, the EDT may never be above the energy of the currently ongoing transmissions, and the channel may only be sensed as idle after at least the currently ongoing transmission has concluded. After the transmission has finished, the EDT of the wideband device is reset to the default value to ensure fairness of the next channel access attempt.

[0094] The discussed procedure can be applied equally well to the example situation given in FIG. 10 where multiple other wideband systems are the cause of the channel blocking.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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 stand-alone software package, partly on the user's computer and partly on a remote computer or entirely 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).

[0101] 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.

[0102] 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.

[0103] Some of the embodiments described herein can be listed as:

[0104] Embodiment Al . A method in a wireless device (WD) in a system, the WD being configured to perform spectrum sharing associated with one or more adaptive Listen-Before- Talk (LBT) operations, the method comprising: detecting a presence of multiple frequency-hopping WDs with high duty cycle; and adapting one or more parameters of the one or more LBT operations based on the detected presence, the one or more parameters determining aggressiveness of channel access. Embodiment A2. The method of Embodiment Al, wherein one or more of: the detection of the multiple frequency-hopping WDs with high duty cycle is performed by recognizing energy without a gap that exceeds a predetermined gap threshold on the channel for a predetermined duration; the gap exceeds the predetermined gap threshold if its duration is equal or longer to a gap duration required between two wideband channel occupancies; and the predetermined duration is the maximum channel occupancy time of the system.

[0105] Embodiment A3. The method of any one of Embodiments Al and A2, wherein one or more of: the adaptation of is performed by increasing an energy detection threshold (EDT) value; the EDT value is increased while the channel stays busy; and the increase of the EDT value cannot exceed a currently sensed energy level.

[0106] Embodiment A4. The method of any one of Embodiments A1-A3, wherein one or both of: the adaptation is applied only to a predetermined frequency part of an available bandwidth; and the one or more parameters are reset to a default value after a successful channel access attempt.

[0107] Embodiment A5. The method of any one of Embodiments A1-A4, wherein the system is a wideband system, and the WD is a wideband device.

[0108] Embodiment Bl. A wireless device (WD) in a system, the WD being configured to perform spectrum sharing associated with one or more adaptive Listen-Before-Talk (LBT) operations, the WD being configured to, and / or comprising a radio interface and / or processing circuitry configured to: detect a presence of multiple frequency-hopping WDs with high duty cycle; and adapt one or more parameters of the one or more LBT operations based on the detected presence, the one or more parameters determining aggressiveness of channel access.

[0109] Embodiment B2. The WD of Embodiment Bl, wherein one or more of: the detection of the multiple frequency-hopping WDs with high duty cycle is performed by recognizing energy without a gap that exceeds a predetermined gap threshold on the channel for a predetermined duration; the gap exceeds the predetermined gap threshold if its duration is equal or longer to a gap duration required between two wideband channel occupancies; and the predetermined duration is the maximum channel occupancy time of the system.

[0110] Embodiment B3. The WD of any one of Embodiments Bl and B2, wherein one or more of: the adaptation of is performed by increasing an energy detection threshold (EDT) value; the EDT value is increased while the channel stays busy; and the increase of the EDT value cannot exceed a currently sensed energy level.

[0111] Embodiment B4. The WD of any one of Embodiments B1-B3, wherein one or both of: the adaptation is applied only to a predetermined frequency part of an available bandwidth; and the one or more parameters are reset to a default value after a successful channel access attempt.

[0112] Embodiment B5. The WD of any one of Embodiments B1-B4, wherein the system is a wideband system, and the WD is a wideband device.

[0113] Embodiment Cl. A method in a network node in a system, the network node being configured communicate with one or more wireless devices (WDs) and to perform spectrum sharing associated with one or more adaptive Listen-Before-Talk (LBT) operations, the method comprising: detecting a presence of multiple frequency -hopping WDs with high duty cycle; and adapting one or more parameters of the one or more LBT operations based on the detected presence, the one or more parameters determining aggressiveness of channel access.

[0114] Embodiment C2. The method of Embodiment Cl, wherein one or more of: the detection of the multiple frequency-hopping WDs with high duty cycle is performed by recognizing energy without a gap that exceeds a predetermined gap threshold on the channel for a predetermined duration; the gap exceeds the predetermined gap threshold if its duration is equal or longer to a gap duration required between two wideband channel occupancies; and the predetermined duration is the maximum channel occupancy time of the system.

[0115] Embodiment C3. The method of any one of Embodiments Cl and C2, wherein one or more of: the adaptation of is performed by increasing an energy detection threshold (EDT) value; the EDT value is increased while the channel stays busy; and the increase of the EDT value cannot exceed a currently sensed energy level.

[0116] Embodiment C4. The method of any one of Embodiments C1-C3, wherein one or both of: the adaptation is applied only to a predetermined frequency part of an available bandwidth; and the one or more parameters are reset to a default value after a successful channel access attempt.

[0117] Embodiment C5. The method of any one of Embodiments C1-C4, wherein one or more of the system is a wideband system, the network node is wideband device, and the WDs are other wideband devices.

[0118] Embodiment DI. A network node in a system, the network node being configured communicate with one or more wireless devices (WDs) and to perform spectrum sharing associated with one or more adaptive Listen-Before-Talk (LBT) operations, the network node being configured to, and / or comprising a radio interface and / or processing circuitry configured to: detect a presence of multiple frequency-hopping WDs with high duty cycle; and adapt one or more parameters of the one or more LBT operations based on the detected presence, the one or more parameters determining aggressiveness of channel access.

[0119] Embodiment D2. The network node of Embodiment DI, wherein one or more of: the detection of the multiple frequency-hopping WDs with high duty cycle is performed by recognizing energy without a gap that exceeds a predetermined gap threshold on the channel for a predetermined duration; the gap exceeds the predetermined gap threshold if its duration is equal or longer to a gap duration required between two wideband channel occupancies; and the predetermined duration is the maximum channel occupancy time of the system.

[0120] Embodiment D3. The network node of any one of Embodiments DI and D2, wherein one or more of: the adaptation of is performed by increasing an energy detection threshold (EDT) value; the EDT value is increased while the channel stays busy; and the increase of the EDT value cannot exceed a currently sensed energy level.

[0121] Embodiment D4. The network node of any one of Embodiments D1-D3, wherein one or both of: the adaptation is applied only to a predetermined frequency part of an available bandwidth; and the one or more parameters are reset to a default value after a successful channel access attempt.

[0122] Embodiment D5. The network node of any one of Embodiments D1-D4, wherein one or more of the system is a wideband system, the network node is wideband device, and the WDs are other wideband devices.

Claims

CLAIMS1. A method of a wireless device, WD, (22) or network node (16) configured to operate within a bandwidth in a spectum-sharing wireless communication system employing Listen-Before-Talk (LBT) operations, the method comprising: adapting (SI 02, SI 06), during a time period, one or more parameters of the one or more LBT operations when there is a continuously occupied channel, and due to a plurality of other interfering devices using different parts of a full bandwidth of the WD's operating bandwidth.

2. The method of claim 1, wherein the one or more parameters are adapted (SI 02, SI 06) to change aggressiveness of channel access such that a likelihood of determining the channel as occupied is reduced.

3. The method of Claim 1 or 2, wherein the time period is the maximum allowed channel occupancy time of the spectrum-sharing wireless communication system.

4. The method of any one of claims 1-3, wherein the adaptation (S102, S106) of the one or more parameters is performed when there is at least a variation of received signal energy at listening exceeding a variation threshold.

5. The method of any one of Claims 1-4, wherein the adaptation (SI 02, SI 06) of the one or more parameters is performed by increasing an energy detection threshold, EDT, value.

6. The method of any one of Claims 1-4, wherein the adaptation (SI 02, SI 06) of the one or more parameters is performed by increasing an energy detection threshold, EDT, value while the channel stays busy.

7. The method of Claim 5 or 6, wherein the increase of the EDT value cannot exceed a currently sensed energy level.

8. The method of any one of Claims 1-7, wherein the adaptation (SI 02, SI 06) of the one or more parameters is applied only to a first part of the WD's operating bandwidth.

9. The method of any one of Claims 1-8, comprising resetting the one or more parameters to a default value after a successful channel access attempt.

10. A wireless device, WD, (22) configured to operate within a bandwidth in a spectum-sharing wireless communication system employing Listen-Before-Talk, LBT, operations, the WD being configured to, and / or comprising a radio interface and / or processing circuitry configured to: adapt, during a time period, one or more parameters of the one or more LBT operations when there is a continuously occupied channel, and due to a plurality of other interfering devices using different parts of a full bandwidth of the WD's operating bandwidth.

11. The WD (22) of Claim 10, wherein the WD (22) being configured to, and / or the radio interface and / or processing circuitry configured to perform the method according to any one of claims 2-9.

12. The WD (22) of Claim 10 or 11, being configured to operate as an access point, AP, station, STA, or a non-AP STA in the spectum sharing wireless communication system.

13. A network node (16) configured to operate within a bandwidth in a spectum- sharing wireless communication system employing Listen-Before-Talk, LBT, operations, the network node (16) being configured to, and / or comprising a radio interface and / or processing circuitry configured to: adapt, during a time period, one or more parameters of the one or more LBT operations when there is a continuously occupied channel, and due to a plurality of other interfering devices using different parts of a full bandwidth of the WD's operating bandwidth.

14. The network node (16) of Claim 12, wherein the network node (16) being configured to, and / or the radio interface and / or processing circuitry configured to perform the method according to any one of claims 2-9.

15. The network node (16) of Claim 13 or 14, being configured to operate as an access point, AP, station, STA, in the spectum sharing wireless communication system.

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