Communication in a license-exempt spectrum

Abstract

A node configured to support communication between two nodes in an unlicensed spectrum is disclosed, wherein the channel can be used for both downlink and uplink communication simultaneously. The method, performed at the node, involves assessing at that node (e.g., a UE) the existence of a transmission to be made to another node (e.g., a gNB). A first node receives an indication regarding the availability of communication with the other node using Flexible Frequency Division Duplex (FDD) technology on the channel within the unlicensed spectrum. The first node determines whether the transmission of the other node is taking place within a first portion of the channel within the unlicensed spectrum; and if so, transmits to the other node within a second portion of the channel that does not overlap with the first portion.

Description

Technical Field

[0001] Various example implementations involve communication within the unlicensed spectrum. Background Technology

[0002] Unlicensed spectrum offers the opportunity to increase the available bandwidth for signals to be transmitted within a network. Because unlicensed spectrum is shared with other devices, scanning may be required before any transmission to mitigate interference within the unlicensed band. Rules may exist regarding the scans performed by the devices. These rules may attempt to allow for the fair sharing of unlicensed spectrum. The processes typically used in sharing unlicensed spectrum can lead to increased latency.

[0003] Unlicensed spectrum is divided into sub-bands or channels, each covering a predetermined frequency range. Scanning processes such as Listen-Before-Speak (LBT) involve sensing a sub-band or channel to determine its availability before signal transmission. If it is determined to be available, the channel can be acquired by a node for a Channel Occupied Time (COT). During the COT, a signal can be transmitted by the node, and other nodes are blocked from using the channel.

[0004] More and more devices are capable of transmitting and receiving on more than one channel, and this can be used to increase throughput and / or reliability. There is a need to provide a system for communicating in unlicensed spectrum in a manner that is both efficient and allows coexistence with other systems. Summary of the Invention

[0005] The scope of protection sought by the various embodiments of the present invention is stated by the independent claims. Embodiments, examples, and features (if any) described in this specification that are not within the scope of the independent claims are to be interpreted as examples useful for understanding the various embodiments of the invention.

[0006] According to various, but not necessarily all, embodiments of the invention, according to a first aspect, a node is provided comprising components configured to: assess at the node the existence of a transmission to another node; receive an indication that communication between the node and the other node is supported using Flexible Frequency Division Duplex (FDD) technology on a channel within unlicensed spectrum; determine whether the transmission of the other node is taking place within a first portion of the channel; and if so, transmit to the other node within a second portion of the channel that does not overlap with the first portion.

[0007] The node-implemented operating mode recognizes that even if the first frequency portion of the channel is being used for communication by another node (e.g., a gNB), transmission by a node (e.g., a user equipment) within the channel is still possible. Specifically, the node can be configured to operate in a manner that improves communication efficiency by determining whether transmission by another node is taking place within the first frequency portion of the channel; and if so, transmitting to the other node within a second frequency portion of the channel that does not overlap with the first frequency portion.

[0008] Indications regarding communication between nodes using Flexible Frequency Division Duplex (FDD) technology on channels within unlicensed spectrum can include broadcast or multicast communication from, for example, the gNB to all UEs within the cell. These indications can include, for example, Physical Downlink Control Channel (PDCCH) messages or signaling.

[0009] A node may include a component configured to determine if a transmission by another node is taking place within the first part of the channel, and the specified duration of the listen-before-speak process performed by the node prior to the transmission is reduced.

[0010] A node may include a determining component configured to determine that if it is determined that a transmission of another node is taking place within the first part of the channel, the initialization of a listen-before-speak process prior to transmission is prevented.

[0011] A node may include a determining component configured to determine whether a transmission by another node is occurring within the first part of the channel by estimating at the node whether another node is performing a transmission within the first part of the channel.

[0012] A node may include an estimation component configured to perform an estimation by detecting one or more signature signals associated with another node.

[0013] One or more signature signals associated with other nodes may include: demodulation reference signals or channel state information reference signals.

[0014] A node may include an estimation component configured to estimate the signal received at the node when communication between the node and another node is supported by flexible frequency division duplex (FDD) technology on a channel within the unlicensed spectrum, in a manner that is associated with the signal received when communication on the channel is reserved for transmission by another node.

[0015] A node can be configured such that when communication between the node and another node is supported on a channel within the unlicensed spectrum using Flexible Frequency Division Duplex (FDD) technology, the specified duration of the listen-before-speak process prior to transmission is reduced, and when communication on the channel immediately preceding the flexible time slot is reserved for transmission by another node.

[0016] A node can be configured such that when communication between the node and another node is supported on a channel within the unlicensed spectrum using Flexible Frequency Division Duplex (FDD) technology, and when communication on the channel immediately preceding the flexible time slot is reserved for transmission by another node, the initialization of the listen-before-speak process prior to transmission is prevented.

[0017] A node may include a component configured to evaluate the duration of a transmission to another node and to transmit only if the transmission is within a predetermined threshold.

[0018] A node may include components configured to assess the duration of a transmission to another node; components for determining at the node that the channel has been acquired by another node for a predetermined occupancy time; and components for transmitting only if the transmission to another node can be performed within the predetermined occupancy time.

[0019] A node may include: components for assessing the duration of a transmission to another node and an indication of whether communication between the node and another node is supported using Flexible Frequency Division Duplex (FDD) technology on a channel within the unlicensed spectrum; components for assessing whether the transmission of the other node is supported in a first part of the channel; and if so, components for transmitting the transmission to be performed in a second part of the channel while the transmission of the other node is supported in the first part of the channel.

[0020] Indications regarding communication between nodes using Flexible Frequency Division Duplex (FDD) technology on channels within the unlicensed spectrum are supported and may include: Slot Format Indicator (SFI) messages.

[0021] The node according to the invention may include: at least one processor; and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to cause operation of the node together with the at least one processor.

[0022] According to various, but not necessarily all, embodiments of the invention, according to a second aspect, a method performed at a node is provided, the method comprising: assessing at the node the existence of a transmission to another node; receiving an indication that communication between the node and the other node is supported using Flexible Frequency Division Duplex (FDD) technology on a channel within unlicensed spectrum; determining whether the transmission of the other node is taking place within a first portion of the channel; and if so, transmitting to the other node within a second portion of the channel that does not overlap with the first portion.

[0023] This method recognizes that even if the first frequency portion of the channel is being used for communication by another node (e.g., a gNB), transmission by a node (e.g., a user equipment) within the channel is still possible. Specifically, the method recognizes that communication efficiency can be improved by determining whether transmission by another node is taking place within the first frequency portion of the channel; and if so, by transmitting to the other node within a second frequency portion of the channel that does not overlap with the first frequency portion.

[0024] This method recognizes that when it is determined that transmission from another node is taking place within the first part of the channel, the specified duration of the listen-before-speak process prior to transmission is reduced.

[0025] The use of unlicensed spectrum may require scanning the channel before communication is initiated to allow coexistence between various devices using the spectrum and the network. The scanning process adds latency and can itself cause additional problems; for example, it may require devices to wait until the unlicensed spectrum is idle for a regulated period of time before attempting to access it. If there are many devices nearby, the latency can be significant. Listen-before-speak (LBT) is an example of such a scanning process.

[0026] This method allows the initialization of the listen-before-speak process to be prevented when it is determined that the transmission of another node is taking place within the first part of the channel.

[0027] This method allows determining whether a transmission by another node is taking place within the first part of the channel to include: estimating at the node whether the other node is performing a transmission within the first part of the channel.

[0028] This method allows the estimation to include detecting one or more signature signals associated with other nodes.

[0029] This method allows one or more signature signals associated with another node to include: a demodulation reference signal or a channel state information reference signal.

[0030] This method allows the estimation to include: the signal received at the node when communication between the node and another node is supported using flexible frequency division duplex (FDD) technology on a channel within the unlicensed spectrum, and the signal received when communication on the channel is reserved for transmission at another node.

[0031] This method enables a reduction in the specified duration of the listen-before-speak process when communication between a node and another node is supported on a channel within the unlicensed spectrum using flexible frequency division duplex (FDD) technology, and when it also indicates that communication on the channel immediately preceding the flexible time slot is reserved for transmission by another node.

[0032] This method enables the initialization of a listen-before-speak process to be prevented when communication between a node and another node is supported on a channel within the unlicensed spectrum using flexible frequency division duplex (FDD) technology, and when it also indicates that communication on the channel immediately preceding the flexible time slot is reserved for transmission by another node.

[0033] The method may include: assessing the duration of a transmission to another node; and only transmitting if the transmission is within a predetermined threshold.

[0034] The method may include: assessing the duration of a transmission to another node; determining at the node that the channel has been acquired by another node for a predetermined occupancy time; and transmitting only if the transmission to the other node can be performed within the predetermined occupancy time.

[0035] The method may include: assessing the duration of a transmission to another node and an indication that communication between the node and the other node is supported using flexible frequency division duplex (FDD) technology on a channel within unlicensed spectrum; assessing whether the transmission to the other node is supported in a first part of the channel; and if so, transmitting the transmission to be performed in a second part of the channel while the transmission to the other node is supported in the first part of the channel.

[0036] This method allows for indications that communication between nodes on unlicensed spectrum channels using Flexible Frequency Division Duplex (FDD) technology can support features such as Slot Format Indicator (SFI) messages.

[0037] This method allows for indications that communication between nodes on unlicensed spectrum channels using flexible frequency division duplex (FDD) technology is supported, which may include indications that one or more time slots are classified for flexible use.

[0038] According to various, but not necessarily all, embodiments of the invention, according to a second aspect, a computer program including computer-readable instructions is provided, which, when executed by a computer on a node, are configured to cause the node to perform the method as described above.

[0039] Further specific and preferred aspects are set forth in the appended independent and dependent claims. Features of the dependent claims may be suitably combined with features of the independent claims, and may be combined with features of the independent claims in combinations other than those expressly specified in the claims.

[0040] When a device feature is described as operable to provide a function, it should be understood that this includes device features that provide the function or are adapted or configured to provide the function. Furthermore, it should be understood that components configured to perform a function include logic or circuitry systems configured to implement that function. Attached Figure Description

[0041] Some exemplary embodiments will now be described with reference to the accompanying drawings, in which:

[0042] Figure 1 A flexible frequency division duplex (FDD) method is illustrated schematically;

[0043] Figure 2 It shows things like Figure 1 A possible problem with the FDD method shown;

[0044] Figure 3 Example embodiments of the subjects described herein are illustrated schematically; and

[0045] Figure 4 The flowchart illustrates an operation block based on an exemplary implementation. Detailed Implementation

[0046] Before discussing the example embodiments in more detail, an overview will first be provided.

[0047] As background, it will be recognized that unlicensed spectrum (New Radio Unlicensed NR-U) operation allows a portion of the spectrum to be shared between networks and devices; for example, mobile / wireless telecommunications networks can share frequency areas used for WiFi communications. Several possibilities exist that allow different schemes to coexist within the unlicensed spectrum.

[0048] A sharing scheme enables shared Channel Occupancy Time (COT) between a next-generation NodeB (gNB) (as the initiating device) and a User Equipment (UE) (as the responding device). According to this scheme, Time Division Duplex (TDD) operation is implemented. Based on the TDD sharing method, the gNB and UE are configured to transmit on the same unlicensed channel / band. Shared COT can be interpreted as the next-generation NodeB (gNB) (as the initiating device) acquiring the "right" to access the channel for a specific time period (COT). This right is acquired through an "extended" Listen-Before-Speak (LBT) procedure (referred to as cat4 LBT).

[0049] COT (Confirmation of Access) may not prevent other devices from accessing the channel. Instead, COT allows priority access to the channel in relation to the initiating and responding devices for a limited time period. Specifically, COT is typically acquired by the initiating device using LBT Type 1, which requires the target channel to be unoccupied for a predetermined amount of time. This amount of time is associated with the traffic priority of the payload to be transmitted by the initiating device. The higher the traffic priority, the less time the channel must be occupied during the LBT check.

[0050] COT acquisition is accomplished by the initiating device performing a transmission in the channel (after a successful LBT check). The initiating device can pause its transmission during the COT and then resume it by performing a shorter LBT (while still within the COT). If the COT has passed, the initiating device must restart resource acquisition. It will be appreciated that if the initiating device pauses its transmission, other devices may be able to access the channel, provided they successfully overcome their own LBT checks.

[0051] The acquired COT can also be used by the responding device (i.e., the device that responds to the transmission from the initiating device) to acquire the channel (in response to the initiating device). The responding device typically needs to implement its own LBT process before making a transmission.

[0052] Because different systems access the shared spectrum asynchronously, multiple devices acting as initiating devices can simultaneously have valid COT (Confirmation of Origin). In other words, even if the COT is valid, as long as the first initiating device suspends its transmission for a sufficiently long time to allow another initiating device to also establish a COT, other devices can still access the same spectrum.

[0053] If a shared COT is acquired, the gNB can be configured to share access channel rights with its responding device (UE), provided that their transmissions occur within the COT acquired by the gNB. Within the shared COT, the UE can apply a “simplified” LBT procedure or not apply LBT at all.

[0054] The following LBT types are defined for uplink (UL) channel access in NR-U:

[0055] Type 1 (Cat4 LBT) – Used for UL transmissions other than COT acquired by gNB.

[0056] • Type 2A (25ms Cat2 LBT) – Used for UL transmissions within the COT acquired by the gNB, where the downlink (DL) to uplink gap is ≥25ms; and for UL transmissions following another UL transmission.

[0057] • Type 2B (16ms Cat2 LBT) – Used for UL transmission within the COT acquired by the gNB, but only for UL transmission after DL (DL-UL gap is exactly 16ms)

[0058] • Type 2C (No UL LBT) – Can only be used for UL transmission after DL, where the DL-UL gap is ≤16ms and the duration of the UL transmission is ≤584ms.

[0059] Other possible sharing schemes that can be implemented in NR-U are frequency division duplex (FDD) solutions for unpaired bands. Such solutions are needed to better meet the evolving use cases of enhanced ultra-reliable low-latency communication (eURLLC) and time-synchronized communication (TSC). These solutions eliminate the undesirable limitations of traditional TDD on unpaired bands, which prevent parallel uplink and downlink transmissions and thus limit eURLLC / TSC performance, particularly in terms of communication latency.

[0060] Figure 1 A flexible frequency division duplex (FDD) method is illustrated schematically. For example... Figure 1 As shown, when operating with a flexible FFD scheme, gNB is configured to enable it to:

[0061] • Dynamically using a portion of the spectrum for UL or DL ​​transmission; and

[0062] • Assuming the frequency interval (Rx / Tx protection band) between UL and DL is minimized, simultaneous transmission and reception are performed on the frequency band.

[0063] Flexible FDD allows for mitigation of latency associated with TDD operations within subbands, while avoiding intra-cell cross-link interference issues associated with in-band full-duplex operations.

[0064] Figure 1A sub-band or channel with a frequency range Y (e.g., 20 MHz) is schematically illustrated. Downlink transmission 10 and uplink transmission 20 can be transmitted within the same frequency range Y, depending on the implementation of appropriate guard bands in time 30 and frequency 40. Multiple frequency guard bands 40 allow for sufficient separation in the transmission and reception frequencies to mitigate interference and signal-to-noise problems. The guard interval 30 can be variable to account for changes in transmission and reception configurations and propagation delays.

[0065] Figure 2 It shows things like Figure 1 One potential problem with the FDD method illustrated is that when implementing a scheme for flexible FDD operation in unlicensed spectrum, the UE may still need to perform a UL LBT procedure before any UL transmission (as described above regarding TDD operation). This is because, if a flexible FDD method is used, the gNB can perform gapless DL transmissions over at least a portion of the acquired subband, which could lead to LBT failures at the UE. Regulations require the transmitter to perform LBT measurements over the entire subband (e.g., the entire 20MHz band), even if DL or UL transmissions only occupy a portion of that subband. As a result, even if a flexible FDD DL transmission only occupies a portion of the subband in the Clear Channel Assessment (CCA) slot before the UL transmission (UE to Tx / Rx guard time), the probability of the UE sensing the channel as busy remains high due to: the high coupling gain between the UE and its serving gNB; and leakage from the serving gNB to the rest of the band. Since the UE detects that channel Y is not idle, it cannot perform a UL transmission. Figure 2 As shown, the gNB can notify the UE within its cell of operating parameters, for example, via signaling 50 transmitted on the Physical Downlink Control Channel (PDCCH). The gNB can continue to transmit 10 on the DL Shared Channel (e.g., the Physical Downlink Shared Channel (PDSCH)). Figure 2 As shown, DL transmission 10 may occupy only a portion of the subband or channel Y. When the UE attempts LBT procedure 60 on the entire channel Y, DL transmission 10 is detected and the UE determines that it cannot perform UL transmission, even though resource 70 is available assuming the network is configured to use flexible FDD technology.

[0066] The embodiments provide nodes configured to transmit channels in unlicensed spectrum in a manner that reduces transmission latency and increases overall throughput. Specifically, the embodiments can implement flexible FDD UL transmission in unlicensed channels, where UL transmission can begin in a first portion of the unlicensed channel while DL transmission is simultaneously occurring on a (non-overlapping) second portion of the unlicensed channel.

[0067] The embodiments introduce UE implementation solutions that do not require explicit signaling, which may introduce additional latency or network inefficiency. The UE-implementation-based embodiments configure the UE to: (i) estimate whether the serving next-generation NodeB (gNB) is performing a simultaneous DL transmission; and (ii) based on that estimate, determine which LBT type should be applied. This estimation can be performed before the UE UL transmission is executed within the UL Configuration Authorization (CG) resource allocation. The embodiments recognize that scanning processes (e.g., LBT processes) increase latency and reduce overall efficiency. The embodiments recognize that nodes within the network (such as UEs) can use available information, sometimes employing estimation and evaluation techniques, to allow communication within flexible FDD schemes without requiring explicit additional signaling.

[0068] It will be recognized that controlled operation of flexible FDD within unlicensed spectrum includes a slot format indicator (SFI) transmitted between the gNB and the UE served by that gNB. The SFI already exists in the current specification for TDD operation and includes indications of DL symbols, UL symbols, and flexible (F) symbols within the slot. The role of the flexible symbol is to indicate that the symbol can act as either UL or DL, and it can also be used to switch between DL and UL (and vice versa). Embodiments of the present invention can use information from the gNB when determining how the UE operates.

[0069] Figure 3 Example embodiments of the subjects described herein are illustrated schematically. According to Figure 3 The illustrated embodiment may include the following blocks:

[0070] S1: The control node (such as the gNB) is configured to notify the UE operating within the cell via PDCCH signaling 50 of the type of communication direction that each symbol within the authorization has been assigned. This direction may include downlink, uplink, or a flexible indication. Communication may be conducted via the use of SFI message 80 or other suitable broadcast or multicast communication methods. This message delivery by the gNB is also used to indicate to the UE that the gNB has acquired COT.

[0071] S2: The user equipment (with UL configuration authorization (CG) allocation) receives, for example, an indication of symbol direction by receiving an SFI, and is configured to interpret the indication and detect which symbols are marked as flexible (F).

[0072] S3: In the symbol identified as F, the UE takes steps to detect whether the gNB is performing a DL transmission. For example, this detection process can take one of the following forms: detection via demodulation reference signal (DMRS); channel state information reference signal (CSI-RS); and / or based on the correlation with the signal in the initial DL symbol.

[0073] S4: Based on the result of detection block S3, the UE is configured as follows:

[0074] S4A: If the serving gNB has been identified as the transmitter and the duration of the UL transmission is less than 0.584 ms, proceed to LBT type 2C and perform the UL transmission 90 within the appropriate frequency range of channel Y using a frequency available as the Physical Uplink Shared Channel (PUSCH); or

[0075] S4B: If any of the following conditions are met, proceed to LBT type 2A:

[0076] - No transmission detected; or

[0077] - The service gNB is not identified as a transmitter; or

[0078] - The duration of the UL transmission to be performed by the UE is greater than 0.584ms.

[0079] Without using the method according to the embodiments, flexible FDD can occur within the unlicensed spectrum if the gNB is configured to introduce at least one gap between two consecutive DL transmissions to allow a potential UE to perform a successful LBT check and continue its UL transmission. These gaps on DL transmissions waste available resources that could otherwise be used for communication. Embodiments can allow flexible FDD operation with DL transmissions that do not need to be interrupted or disrupted to allow the UE to perform the LBT procedure before the UE's UL transmission. Specifically, the gNB can perform DL on the first portion of the unlicensed channel and DL-UL handover on the second portion of the same unlicensed channel without introducing additional signaling. In other words, some embodiments can allow a reduced scanning procedure or no scanning procedure before the UE begins transmission.

[0080] The implementation can be particularly useful for UL configuration grant allocation, where the UE is allocated a periodic semi-static Physical Uplink Shared Channel (PUSCH), and therefore the gNB cannot specifically indicate the LBT type when allocating those PUSCH resources. However, it should be understood that the implementation can also be applied to scheduling PUSCH transmissions, particularly scheduling PUSCH transmissions outside of the COT acquired by the gNB.

[0081] Figure 4 The flowchart illustrates an operation block executed by the UE to select the appropriate transport mechanism or LBT procedure according to an exemplary implementation.

[0082] S100: The UE determines that it has a Physical Uplink Shared Channel (PUSCCH) transmission to perform, starting with symbol #x in time slot #N and ending with symbol #y in time slot #M. The UE has an initial LBT type of type 1 (Cat4) (e.g., associated with a scheduled PUSCH other than the COT obtained by the UL configuration authorization or gNB).

[0083] S110: Is this time slot N? If so, proceed to S120.

[0084] S120: The UE checks, for example, downlink control information (DCI) sent on the PDCCH. The DCI may include a slot format indicator (SFI) message and a COT from the serving gNB.

[0085] If such a message is not detected at the UE, the UE is configured to implement LBT, type 1 (cat4) T1.

[0086] If message transmission is detected, the UE proceeds to frame S130.

[0087] S130: The UE decodes and processes the SFI message and identifies F time slots, then proceeds to frame S140.

[0088] S140: UE operation to determine whether the symbol #y of time slot #M is within the determined COT?

[0089] If not, the UE is configured to implement LBT, type 1 (cat4) T1.

[0090] If so, the UE proceeds to frame S150.

[0091] S150: UE operation to determine whether at least one type F time slot exists before symbol #x.

[0092] If not, the UE is configured to determine whether the previous time slot of S155 is type D:

[0093] If not, the UE is configured to implement LBT, type 2A(cat2)T2A

[0094] If so, the UE is configured to implement LBT, type 2C (without LBT)T2C

[0095] If S150 reveals that there is at least one type F time slot before symbol #x, then the UE proceeds to frame S160.

[0096] S160: The UE is configured to attempt to detect DL transmissions from the serving gNB, and the detection method used may be any of those methods described in more detail below.

[0097] S170: The UE is configured to determine whether a DL transmission from the serving gNB is detected in frame S160.

[0098] If not, the UE is configured to implement LBT, type 2A(cat2)T2A

[0099] If so, the UE is configured to implement LBT, type 2C (without LBT)T2C

[0100] S180: Once the UE (T1, T2A, T2C) selects the appropriate LBT type associated with the PUSCH transmission of interest, the UE executes the LBT procedure and determines whether the result of the LBT procedure is positive. If yes, the UE continues to execute the uplink transmission.

[0101] S190: If the result of the LBT process is not positive, the process is restarted.

[0102] UE detection for DL ​​transmission

[0103] The UE can detect the presence of DL transmissions from the serving gNB in ​​various ways. For example, detection can be performed via: detection of a specific DL DMRS port / sequence; CSI-RS detection; and / or based on the correlation between a signal present in a time slot identified as F and a signal appearing in a time slot identified as D, for example, whenever D is present in the same time slot or k previous time slots within the relevant time period of the channel at the UE receiver. Changes in UL transmission duration in LBT Type 2C

[0104] According to certain channel access regulations, when a UE applies LBT type 2C, the duration of its UL transmission is limited to ≤584μs. In flexible FDD operation, if DL transmission is still in progress and the UE is aware of the ongoing transmission, the UE can extend its transmission beyond 584μs, thereby improving efficiency and throughput. However, while improving efficiency, simply extending the UL transmission can have unintended consequences if a "hidden node" exists. By extending the UE UL transmission, the UE will restrict channel access for any hidden node, as the hidden node's own LBT process will fail. To address this, some embodiments may require the UE to perform sensing across the entire channel to estimate the presence of potential hidden nodes. This sensing can occur before the UL transmission. The sensing period can be enabled during gNB quiescent periods in the time and / or frequency domains. For example, in some embodiments, the UE can measure the power in empty frequency resources prior to uplink transmissions and, for LBT power sensing purposes, conservatively insert that power across the entire channel size to account for the potential presence of hidden nodes. In other words, the UE can perform hidden node sensing within a known time period when the gNB is not performing any DL transmissions. Extended UL transmission can be enabled or prevented based on channel estimation results. If the certainty of the presence of a hidden node is higher than a certain threshold, the UE can be prevented from transmitting for more than 584 μs. If the certainty of the presence of a hidden node is lower than a certain threshold, the UE can be allowed to transmit for more than 584 μs.

[0105] Those skilled in the art will readily recognize that blocks of the various methods described above can be executed by a programmed computer. Here, some embodiments are also intended to cover program storage devices, such as digital data storage media, that are machine- or computer-readable and encoded with a program of machine-executable or computer-executable instructions, wherein these instructions perform some or all of the steps of the methods described above. The program storage device may be, for example, a digital memory, a magnetic storage medium such as a disk and magnetic tape, a hard disk drive, or an optically readable digital data storage medium. Embodiments are also intended to cover computers programmed to perform the steps of the methods described above.

[0106] Although embodiments of the invention have been described with reference to various examples in the preceding paragraphs, it should be understood that modifications may be made to the given examples without departing from the scope of the claimed invention.

[0107] The features described above may be used in combinations other than those explicitly described.

[0108] Although the functions have been described with reference to certain features, these functions can be performed through other features, whether or not they are described.

[0109] Although features have been described with reference to certain embodiments, these features may exist in other embodiments, whether or not they are described.

[0110] Although the foregoing description has made efforts to draw attention to those features of the invention that are considered particularly important, it should be understood that the applicant claims protection for any patentable features or combinations thereof mentioned above and / or shown in the drawings, whether or not they are specifically emphasized.

Claims

1. A node for communication, comprising: A component configured to evaluate at the node the existence of a transmission to be made to another node; The component is configured to receive an indication regarding the support for flexible frequency division duplex (FDD) technology on a channel within unlicensed spectrum for communication between the node and the other node. Configured to determine whether the transmission of the other node is occurring within a first frequency portion of the channel, and if the transmission of the other node is occurring within the first frequency portion of the channel, then a component is prevented from initiating a listen-before-speak process before transmission. A component configured to transmit to the additional node within a second frequency portion of the channel that does not overlap with the first frequency portion.

2. The node according to claim 1, wherein the component comprises: At least one processor; as well as At least one memory including computer program code, the at least one memory and the computer program code being configured together with the at least one processor to enable the operation of the node.

3. The node according to claim 1 or claim 2, wherein when it is determined that the transmission of the other node is taking place within a first frequency portion of the channel, the specified duration of the listen-before-speak process prior to transmission is reduced.

4. The node of claim 1, wherein the component for determining whether the transmission of the other node is taking place within a first frequency portion of the channel is configured to: estimate at the node whether the other node is performing a transmission within a first frequency portion of the channel.

5. The node of claim 4, wherein the estimation comprises: Detect one or more signature signals associated with the other node.

6. The node of claim 5, wherein the one or more signature signals associated with the additional node comprise: Demodulation reference signal, or channel state information reference signal.

7. The node of claim 4, wherein the estimation comprises: The use of Flexible Frequency Division Duplex (FDD) technology on a channel within the unlicensed spectrum for communication between the node and the other node is supported when the signal received at the node is associated with the signal received when communication on the channel is reserved for transmission at the other node.

8. The node according to claim 1 or claim 2, wherein when communication between the node and the other node is supported using flexible frequency division duplex (FDD) technology on a channel within the unlicensed spectrum, the indication further indicates that communication on the channel immediately preceding the flexible time slot is reserved for transmission of the other node, and the specified duration of the listen-before-speak process prior to transmission is reduced.

9. The node according to claim 1 or claim 2, wherein when communication between the node and the other node is supported using flexible frequency division duplex (FDD) technology on a channel within the unlicensed spectrum, and the indication further indicates that communication on the channel immediately preceding the flexible time slot is reserved for transmission of the other node, the initialization of the listen-before-speak process prior to transmission is prevented.

10. The node according to claim 1, comprising: A component configured to evaluate the duration of the transmission to be made to the other node; as well as A component configured to transmit only when the transmission is within a predetermined threshold.

11. The node according to claim 1, comprising: A component configured to evaluate the duration of the transmission to be made to the other node; A component configured at the node to determine that the channel has been acquired by the other node for a predetermined period of time; as well as A component configured to transmit only if the transmission to the other node can be performed within the predetermined time period.

12. The node according to claim 1, comprising: The component is configured to assess the duration of the transmission to the other node and the indication that the communication between the node and the other node is supported by flexible frequency division duplex (FDD) technology on a channel within the unlicensed spectrum. A component configured to evaluate whether the transmission of the additional node is supported in the first frequency portion of the channel; And if the transmission of the other node is supported in the first frequency portion of the channel, then A component configured to transmit the transmission to be performed in the second frequency portion of the channel while the transmission at the other node is supported in the first frequency portion of the channel.

13. A method performed at a node for communication, the method comprising: At the node, an assessment is made to determine if a transmission to another node is necessary. The system receives an indication that communication between the node and the other node using Flexible Frequency Division Duplex (FDD) technology on a channel within the unlicensed spectrum is supported. Determine whether the transmission of the other node is occurring within the first frequency portion of the channel; if the transmission of the other node is occurring within the first frequency portion of the channel, then the initialization of the listen-before-speak process prior to transmission is prevented, and Transmission to the other node occurs within a second frequency portion of the channel that does not overlap with the first frequency portion.

14. A computer program comprising computer-readable instructions, which, when executed by a computer on a node, are configured to cause the node to perform the method according to claim 13.

15. A node for communication, comprising: At least one processor; as well as At least one memory including computer program code, the at least one memory and the computer program code being configured together with the at least one processor to cause the node to: At the node, an assessment is made to determine if a transmission to another node is necessary. The system receives an indication that communication between the node and the other node using Flexible Frequency Division Duplex (FDD) technology on a channel within the unlicensed spectrum is supported. Determine whether the transmission of the other node is occurring within the first frequency portion of the channel; if the transmission of the other node is occurring within the first frequency portion of the channel, then the initialization of the listen-before-speak process prior to transmission is prevented, and Transmission to the other node occurs within a second frequency portion of the channel that does not overlap with the first frequency portion.

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