Patent ID: 12262409

DETAILED DESCRIPTION

One way to utilise the unlicensed spectrum reliably is to transmit essential control signals and channels on a licensed carrier. That is, as shown inFIG.6, a wireless device is connected to a PCell in e.g, the licensed band and one or more SCells in the unlicensed band. In this application a secondary cell in unlicensed spectrum is denoted as a licensed-assisted access secondary cell (LAA SCell).

In the unlicensed band, a wireless device or an access point performs LBT in order to access the channel for data transmission or sending scheduling information. In LAA with uplink, UL, transmission on the unlicensed band, an access point controls the UL scheduling of one or multiple wireless devices. On the UL, the wireless devices may perform a short LBT with a limited contention window (CW) before transmission or may transmit after the completion of a successful defer period, or may follow some similar LBT procedure. Each wireless device therefore should maintain a set of UL LBT parameters including the current CW, length of defer period, random backoff counter, length of initial CCA (if any), duration of quick CCAs on channels other than the principal random backoff channel, rate of CW size adaptation (if any), triggers used to adapt CW size, etc.

Uplink Hybrid Automatic Repeat Request (HARQ) in LAA is now asynchronous with the Physical Hybrid-ARQ Indicator Channel, (PHICH) being absent. So the wireless device does not know whether its packet was received and whether its uplink LBT parameters should be modified until it is explicitly rescheduled by the scheduling node. In the interim period before new scheduling/rescheduling grants from the scheduling node, the wireless device may therefore be using suboptimal UL LBT parameters. Other examples of a scheduling node are an Access Point, a Base Station, a Radio Base Station, a Base Station Controller, and a Radio Node Controller.

A mismatch in UL LBT parameters also makes UL multiplexing more difficult, since wireless devices scheduled in the same subframe are less likely to transmit simultaneously. The scheduling node generally has greater access to network-wide information such as traffic load and may make better choices for LBT parameters of the scheduled wireless devices.

Thus, the choice of parameters used in the LBT procedure prior to accessing the channel has a major impact on inter-RAT coexistence and throughput.

It is therefore an object of embodiments herein to ensure that one or more LBT parameters are regularly or continuously determined e.g. updated and/or adjusted and that a scheduled wireless device is provided with the determined, updated or adjusted one or more LBT parameters.

Embodiments herein relate to wireless communication networks in general.FIG.7ais a schematic overview depicting a wireless communication network1. The wireless communication network1comprises one or more RANs and one or more CNs. The wireless communication network1may use a number of different technologies, such as Wi-Fi, Long Term Evolution (LTE), LTE-Advanced, 5G, MulteFire, LTE-Unlicensed (LTE-U), Licensed Assisted Access (LAA). Wideband Code Division Multiple Access (WCDMA). Global System for Mobile communications/enhanced Data rate for GSM Evolution (GSM/EDGE). Worldwide Interoperability for Microwave Access (WiMax), or Ultra Mobile Broadband (UMB), just to mention a few possible implementations. Embodiments herein relate to recent technology trends that are of particular interest in a 5G context such as MulteFire. LTE-Unlicensed (LTE-U), and Licensed Assisted Access (LAA), however, embodiments are also applicable in further development of the existing wireless communication systems such as e.g. WCDMA and LTE.

In the wireless communication network1, wireless devices e.g. a wireless device10such as a mobile station, a non-access point (non-AP) STA, a STA, a user equipment and/or a wireless terminals, communicate via one or more Access Networks (AN), e.g. RAN, to one or more core networks (CN). It should be understood by the skilled in the art that “wireless device” is a non-limiting term which means any terminal, wireless communication terminal, user equipment, Machine Type Communication (MTC) device, Device to Device (D2D) terminal, or node e.g. smart phone, laptop, mobile phone, sensor, relay, mobile tablets or even a small base station communicating within a cell.

The wireless communication network1comprises a first access point, denoted as scheduling node12providing radio coverage over a geographical area, a first service area11, of a first radio access technology (RAT), such as LTE, Wi-Fi or similar. The scheduling node12may be a transmission and reception point e.g. a radio network node such as a Wireless Local Area Network (WLAN) access point or an Access Point Station (AP STA), an access controller, a base station, e.g. a radio base station such as a NodeB, an evolved Node B (eNB, eNode B), a base transceiver station, a radio remote unit, an Access Point Base Station, a base station router, a transmission arrangement of a radio base station, a stand-alone access point or any other network unit capable of communicating with a wireless device within the area served by the scheduling node12depending e.g. on the first radio access technology and terminology used. The scheduling node12may be referred to as a serving access point and communicates with the wireless device10with DL transmissions to the wireless device10and UL transmissions from the wireless device10.

Furthermore, the wireless communication network1comprises a second access point13providing radio coverage over a geographical area, a second area14, of a second RAT, such as LTE. Wi-Fi, WiMAX or similar. The second access point13may be a transmission and reception point e.g. a radio network node such as a WLAN access point or an Access Point Station (AP STA), an access controller, a base station, e.g. a radio base station such as a NodeB, an evolved Node B (eNB, eNode B), a base transceiver station, a radio remote unit, an Access Point Base Station, a base station router, a transmission arrangement of a radio base station, a stand-alone access point or any other network unit capable of communicating with a wireless device within the area served by the second access point13depending e.g. on the second radio access technology and terminology used.

The first and second RAT may be the same or different RATs and the first service area11may be referred to as a first beam group, first beam or a first cell such as a primary cell (PCell). The second service area14may be referred to as a second beam group, second beam or a second cell such as a secondary cell (SCell). It should be noted that the second service area14may be provided by the same access point as the first service area i.e. by the scheduling node12.

The scheduling node12may coordinate communication with the second access point13in the wireless communication network1. This is done by communicating with one another over a backhaul connection, e.g. an X2 connection, an Si connection or similar, between the scheduling node12and the second access point13. The scheduling node12may schedule transmissions to and from the wireless device10for both the scheduling node12as well as the second access node13.

The wireless device10is configured to perform an LBT procedure to transmit data in the second service area14. According to embodiments herein, the LBT parameters of the scheduled device(s), i.e, the wireless device10, may be dynamically determined or adjusted by the scheduling node12via e.g. L1 signalling. The LBT parameters that may be adjusted include: the current CW, length of defer period, random backoff counters, length of initial CCA (if any), duration of quick CCAs on channels other than the principal random backoff channel, rate of CW size adaptation (if any), and triggers used to adapt CW size. An example is to signal these parameters in a downlink control information (DCI) of scheduling grants.

Embodiments herein thus describe different examples of how the LBT parameters of one or more scheduled devices, such as the wireless device10, may be dynamically determined or adjusted by the scheduling node12when operating in unlicensed bands in second service area14. The LBT parameters that may be adjusted include as stated above, but is not limited to, the current CW, length of defer period, random backoff counters, length of initial CCA (if any), duration of quick CCAs on channels other than the principal random backoff channel, rate of CW size adaptation (if any), and triggers used to adapt CW size.

FIG.7bis a combined flowchart and signalling scheme according to embodiments herein.

Action701. The scheduling node12determines, e.g. adjusts dynamically, at least one LBT parameter associated with an LBT procedure.

Action702. The scheduling node12informs the wireless device10about the determined at least one LBT parameter in a scheduling grant of the uplink transmission e.g. for data transmission in licensed spectrum.

Action703. The wireless device10then uses the at least one LBT parameter in the LBT procedure when transmitting data according to the received scheduling grant.

The method actions performed by the scheduling node12, exemplified herein as the first access point, for scheduling an uplink transmission from the wireless device10to the scheduling node12according to some embodiments will now be described with reference to a flowchart depicted inFIG.7c. The wireless device10is connected to the Pcell of the scheduling node12in a licensed or unlicensed frequency band. The wireless device10is also connected to at least one SCell in an unlicensed frequency band. The actions do not have to be taken in the order stated below, but may be taken in any suitable order. Actions performed in some embodiments are marked with dashed boxes.

Action711. The scheduling node12determines at least one LBT parameter associated with an LBT procedure. The at least one LBT parameter may be specific for the wireless device10or is common for a plurality of wireless devices that are associated with the scheduling node12. The at least one LBT parameter may be one of: CW size, length of defer period, random backoff counter, length of initial CCA, duration of quick CCAs on channels other than the principal random backoff channel, rate of CW size adaptation, triggers to adapt CW size.

Action712. The scheduling node12may schedule the uplink transmission to a single subframe or a burst of subframes; and corresponding scheduling information is added to the scheduling grant. The scheduling node12may determine a delay between a joint grant transmission and a first uplink subframe and schedule multiple uplink subframes using the joint grant transmission. The first uplink subframe is scheduled based on the determined delay, wherein the delay may be determined based on a downlink data buffer and the number of uplink subframes scheduled by means of a joint grant is based on the uplink buffer of the wireless device. The delay may take an LBT process into account for the wireless device10to perform the LBT before transmitting the UL data.

Action713. The scheduling node12informs the wireless device10about the determined at least one LBT parameter in the scheduling grant of the uplink transmission. The scheduling node12may inform the wireless device10of the at least one LBT parameter by means of a common search space on the PDCCH, or another downlink control channel. The scheduling node12may inform the wireless device10of the at least one LBT parameter by means of broadcasting. The at least one LBT parameter may be an actual/absolute value of the LBT parameter or an offset to be added/subtracted to a current value of the LBT parameter. The scheduling node12may determine in action711at least two different sets of LBT parameters for the wireless device10to be used by the wireless device10in successive LBT attempts. Which set to be used by the wireless device10may be determined according to a predefined rule or predefined table and may be signalled to the wireless device10. The wireless device10may be configured with different sets of LBT parameters. The sets may contain CW sizes in increasing order for consecutive LBT attempts and their corresponding length of defer period. The wireless device10may be indicated which set to use by signalling, via higher layer signalling or L1 signalling. Furthermore, an index of the LBT attempt k, may be signalled to the wireless device10as well.

Action714. The scheduling node12may signal, to the wireless device10, a maximum transmission duration. E.g. in unlicensed spectrum, the wireless device can transmit continuously only up to the maximum transmission duration, according to regulation e.g., 6 ms or 8 ms, not needing to perform LBT during the transmission duration.

An example of an LAA uplink transmission spanning several subframes subsequent to a successful uplink LBT procedure is shown inFIG.7d.

The uplink, UL. LBT is performed prior to an UL transmission based on a previously-received UL resource grant sent by the scheduling SCell or PCell. Multiple wireless devices may perform LBT procedures in parallel if they have been scheduled in the same UL subframe.

The major LBT parameters of the LBT procedure performed by the wireless devices may include:the current CW (upper and/or lower limit),length of defer period.random backoff counters, where separate random backoff counters may be used for separate unlicensed channels.length of initial CCA (if any),duration of quick CCAs on channels other than the principal random backoff channel, if the full LBT procedure with random backoff is performed only on one such channel,rate of CW size adaptation (if any), and/ortriggers used to adapt CW size.

In the following, different example embodiments in which one or more of the above LBT parameters may be signalled by the scheduling node12are provided. The adaptation of parameters may be performed by signalling an absolute value of the new parameter(s), or by signalling a differential quantity by which to step up or step down the current parameter value. The time duration for which the signalled parameters should be adopted by the scheduled devices may also be included in the LBT parameter signalling, or may be defined semi-statically using higher-layer signalling. A subset of the above LBT parameters may also be signalled using higher-layer signalling. A non-limiting example of said higher layer signalling is the radio resource control (RRC) layer signalling in LTE.

In a first exemplifying embodiment, the one or more LBT parameters are signalled using new fields in e.g, the DCI associated with resource allocation grants sent on the (E)PDCCH. These grants may typically be located in the wireless device-specific search space. The scheduling grants containing the at least one LBT parameter may correspond to a single subframe or a burst of subframes such as in a joint grant on a particular channel, or a single subframe or burst of subframes across multiple channels, such as in a multi-carrier grant. The multiple subframes scheduled by a joint grant are not necessarily consecutive.FIG.8illustrates an example of a joint grant transmission where one DL subframe contains UL grants for several consecutive UL subframes.FIG.9illustrates another example of a joint grant transmission with non-consecutive UL subframes. In the following L is the number of UL subframes scheduled by the joint grant. Hardware limitations may impose a minimum delay between the joint grant reception and the start of the first scheduled UL subframe.8is the minimum number of subframes required between the start of the DL subframe with the joint grant and the start of the first UL subframe. In the example ofFIG.8andFIG.9, L=4 and 8=4.

As a non-limiting example, the scheduling node12may signal a common random backoff counter to all wireless devices scheduled for UL transmission starting in the same subframe or burst of subframes.

In another non-limiting example, the scheduling node12may signal wireless devices, i.e. scheduled devices, to adopt only a defer period without additional random backoff for a particular UL subframe or burst of subframes.

In another non-limiting example, the scheduling node12may signal a common random backoff counter and defer period to all wireless devices scheduled for UL transmission starting in the same subframe or burst of subframes.

In a second exemplifying embodiment, the LBT parameters that should be adopted by multiple wireless devices, e.g. scheduled devices, associated with the scheduling node12is signalled in the common search space which is typically used for paging, transmit power control commands, and system information signalling. A new RNTI may be defined for this purpose. The common search space is for example, a common PDCCH control region in a subframe that is known to a plurality of devices.

In a third exemplifying embodiment, the LBT parameters may be embedded in broadcast signals such as the Discovery Reference Signal (DRS) or System Information Blocks (SIB). Here, the adaptation of LBT parameters may be on a slower time scale compared to the use of scheduling grants.

In a fourth exemplifying embodiment, the wireless device10may be granted resource in the UL spanning longer than the allowed maximum transmission duration of a wireless device or a set of wireless devices. The wireless device10may after the maximum transmission duration re-do the channel access scheme to check whether it may continue transmitting within another transmission duration. The maximum transmission duration may be signalled to the wireless device10within the DCI format directly, e.g. as a specific subframe where the channel access scheme shall be performed as a counter based on the number of subframe the wireless device10is allowed to transmit. Another option is that the wireless device10is signalled by higher layer what the maximum transmission duration is. Yet another option is that it is always fixed to a specific value.

In a fifth exemplifying embodiment, the scheduling node12schedules multiple UL subframes using a joint grant transmission and the delay between the joint grant transmission and the first UL subframe is determined according to the downlink (DL) data buffer. In this embodiment the first UL subframe signalled in the joint grant transmitted by the scheduling node12depends on the downlink (DL) data buffer.

FIG.10gives an example of how this may be applied if the accumulated duration of all L UL subframes scheduled by means of a joint grant does not exceed the maximum allowed transmission duration and if 6<=L. InFIG.10is S=L=4. When the scheduling node12has DL data in the buffer to be transmitted to any served wireless device, the UL grant transmitted in subframe n corresponds to a first UL subframe starting in subframe n+5. This enables to fill in the subframes n to n+δ−1 with DL data. When the scheduling node12does not have DL data in buffer, the joint UL grant transmitted in subframe n corresponds to an UL burst starting in subframe n+L+2. This enables to interlace perfectly the DL subframes containing the UL grant and the UL subframes without leaving any unscheduled subframe after an initialisation phase, which would lead to reduced UL data rate.

In a sixth exemplifying embodiment, the number of UL subframes scheduled by means of a joint grant is adapted to the UL buffer situation of the wireless device10. e.g. the scheduled device, to be scheduled. In LTE, estimates of the buffer situation are regularly obtained by the scheduling node12e.g. by means of buffer status report (BSR) sent by wireless devices. If the wireless device10for which the joint grant is intended has much UL data in the buffer, a large number of UL subframes scheduled in a joint grant is beneficial.

In addition to the buffer situation, the UL spectral efficiency of the to-be-scheduled wireless device10, obtained via measurements of past UL transmission or via a prediction or estimation algorithm in the scheduling node12, may be used to determine the optimal number of UL subframes to schedule by means of a joint grant. If the scheduled wireless device10is able to empty its buffer quickly, only a few UL subframes must or may be scheduled in a joint grant. Otherwise, long-term scheduling by means of a joint grant may restrict unnecessarily the number of scheduling opportunities for other wireless devices.

The number of UL subframes scheduled by means of a joint grant may also be adapted to the traffic load, and/or to the length of the queue in the BS scheduler, and/or to the fairness metric of the considered wireless device10compared to the fairness metric of other wireless devices, and/or to the traffic type of other active wireless devices. Example: if the BS serves other wireless devices with real-time (UL or DL) traffic, such as Voice over IP (VoIP), it might be preferable not to schedule in advance a large number of subframes to the same wireless device10, this may remove the possibility to schedule another wireless device with highest priority in-between. LBT gaps, indicated by the at least one LBT parameter, may need to be indicated for the multiple UL subframes scheduled via the joint grant, which is indicating the UL scheduling.

In a seventh exemplifying embodiment, the wireless devices may be configured with different sets of LBT parameters. The sets may contain the CW sizes in increasing order for consecutive LBT attempts and their corresponding length of defer period. Based on pre-defined rules, or pre-defined tables the scheduled device knows how to change the LBT parameters in consecutive LBT attempts for a particular transmission burst. Examples are given for two sets in table 1 inFIG.11aand table 2 inFIG.11bwhere s is the table index, K is the maximum size of the set, k is the LBT attempt modulo K, and CWs (k) is the size of the CW for the set s and LBT attempt k modulo K. Table 1 illustrates an example of LBT parameters in form of pre-defined tables in set s=1, with K=5 and defer period=23 μs for all k; and table 2 illustrates examples of LBT parameters in form of pre-defined tables in set s=2, with K=8, and defer period =43 μs for all k.

In a non-limiting example the scheduled device, i.e, the wireless device10, is indicated which set to use by signalling s via higher layer signalling or L1 signalling. The wireless device10may also be preconfigured to use a default set, and only change the set if it is signalled to do so, by RRC or L1 signalling.

Moreover, the wireless device10determines the CW size by using k, being LBT attempt modulo K, according to the tables or pre-defined rules. Via higher layer or L1 signalling, for example one bit, the scheduled device knows if it has to reset the CW to minimum, i.e. to CWs(k=0) or not. Otherwise, it determines the corresponding CW size based on the parameter k and s.

In another non-liming example, the wireless device10resets the CW size to minimum if some conditions are met without being signalled to do so. Some examples of the triggers for resetting the CW to minimum are as follows:The wireless device10may be granted resource in the UL spanning longer than the allowed maximum transmission duration of a wireless device or a set of wireless devices. The wireless device10is signalled to reset the CW size for the LBT attempt after the maximum transmission duration, in order to check whether it may continue transmitting within another transmission duration.The wireless device10may be granted resources in the UL spanning longer than the allowed maximum transmission duration of a wireless device or a set of wireless devices. The wireless device10may after the maximum transmission duration re-do the channel access scheme to check whether it may continue transmitting within another transmission duration by resetting the CW size.The wireless device10may be granted resources in the UL spanning longer than one subframe. The wireless device10is signalled to reset the CW size for the LBT attempts taking place with an offset from the UL grant after a specific subframe or at specific subframe(s) within the granted resources.The wireless device10may be granted resources in the UL spanning longer than one subframe. The wireless device10resets the CW size for the LBT attempts taking place with an offset from the UL grant after a specific subframe or at specific subframe(s) within the granted resources.The offset from the UL grant may be for example a default value of RRC configured or signalled via L1 signalling.An example for a rule to determine the specific subframes may be every other subframe after that offset as specific subframes.

In another non-limiting example, the index of the LBT attempt k, may be signalled to the wireless device10as well.

The method actions performed by the wireless device10for performing the uplink transmission to the scheduling node12, according to some embodiments will now be described with reference to a flowchart depicted inFIG.12. The actions do not have to be taken in the order stated below, but may be taken in any suitable order. Actions performed in some embodiments are marked with dashed boxes. The wireless device10is connected to the Pcell of the scheduling node12in the licensed or unlicensed frequency band, and the wireless device10is also connected to at least one SCell in the unlicensed frequency band.

Action1201. The wireless device10may receive, from the scheduling node12, configuring information indicating different sets of LBT parameters.

Action1202. The wireless device10receives information, in the scheduling grant of the uplink transmission, of the at least one LBT parameter associated with an LBT procedure. For example, the wireless device10may receive the information by means of a common search space on a PDCCH or another downlink control channel, or receive the information in a broadcast. Information. The wireless device10may alternatively or additionally receive information indicating which set to use by receiving via higher layer signalling or L1 signalling.

Action1203. The wireless device10performs the LBT procedure using the at least one LBT parameter when transmitting data according to the received scheduling grant. The wireless device10may be configured to use a default set and only change the set when signalled to do so by RRC signalling or L1 signalling.

Action1204. The wireless device10may change the at least one LBT parameter in consecutive LBT attempts for a particular transmission burst based on pre-defined rules, or pre-defined tables.

Action1205. The wireless device10may receive, from the scheduling node12, the maximum transmission duration.

Action1206. In some embodiments the at least one LBT parameter comprises a CW size and the wireless device10may reset the CW size to a minimum value if some conditions are met.

FIG.13is a block diagram of the scheduling node12according to an exemplifying embodiment of the scheduling node12for scheduling the uplink transmission from the wireless device10to the scheduling node12. The scheduling node12is configured to serve the Pcell in a licensed or unlicensed frequency band and which wireless device10is configured to connect to the Pcell. The wireless device10is also configured to connect to at least one SCell in an unlicensed frequency band.FIG.13illustrates the scheduling node12comprising a processor1321and memory1322, the memory comprising instructions. e.g. by means of a computer program1323, which when executed by the processor1321causes the scheduling node12to perform a method according to the solution according to the different examples and embodiments described herein.

The processor1321, and/or the scheduling node12may be configured to determine at least one LBT parameter associated with the LBT procedure. The at least one LBT parameter may be specific for the wireless device or is common for a plurality of wireless devices that are associated with the scheduling node12. The at least one LBT parameter may be one of: CW size, length of defer period, random backoff counter, length of initial CCA, duration of quick CCAs on channels other than the principal random backoff channel, rate of CW size adaptation, triggers to adapt CW size. The at least one LBT parameter may be an actual/absolute value of the LBT parameter or an offset to be added/subtracted to a current value of the LBT parameter.

The processor1321, and/or the scheduling node12may be configured to inform the wireless device10about the determined at least one LBT parameter in a scheduling grant of the uplink transmission.

The processor1321, and/or the scheduling node12may be configured to schedule the uplink transmission to a single subframe or a burst of subframes; and to add corresponding scheduling information to the scheduling grant.

The processor1321, and/or the scheduling node12may be configured to schedule the uplink transmission by being configured to determine a delay between the joint grant transmission and the first uplink subframe and schedule multiple uplink subframes using the joint grant transmission. The processor1321, and/or the scheduling node12may then be configured to schedule the first uplink subframe based on the determined delay, and wherein the processor1321, and/or the scheduling node12may be configured to determine the delay based on a downlink data buffer and schedule the number of uplink subframes by means of a joint grant based on the uplink buffer of the wireless device.

The processor1321, and/or the scheduling node12may be configured to inform the wireless device of the at least one LBT parameter by means of a common search space on the PDCCH or another downlink control channel.

The processor1321, and/or the scheduling node12may be configured to inform the wireless device of the at least one LBT parameter by means of broadcasting.

The processor1321, and/or the scheduling node12may be configured to signal, to the wireless device10, a maximum transmission duration.

The processor1321, and/or the scheduling node12may be configured to determine the at least one LBT parameter by being configured to determine at least two different sets of LBT parameters for the wireless device10to be used by the wireless device10in successive LBT attempts. The processor1321, and/or the scheduling node12may be configured to determine which set to be used by the wireless device10according to a predefined rule or predefined table and the processor1321, and/or the scheduling node12may be configured to signal which set to use to the wireless device10.

FIG.13also illustrates the scheduling node12comprising a memory1310. It shall be pointed out thatFIG.13is merely an exemplifying illustration and memory1310may be optional, be a part of the memory1322or be a further memory of the scheduling node12. The memory may for example comprise information relating to the scheduling node12, to statistics of operation of the scheduling node12, just to give a couple of illustrating examples.FIG.13further illustrates the scheduling node12comprising processing means1320, which comprises the memory1322and the processor1321. Still further,FIG.13illustrates the scheduling node12comprising a communication unit1330. The communication unit1330may comprise an interface through which the scheduling node12communicates with other nodes, devices, UEs or entities of the communication network.FIG.13also illustrates the scheduling node12comprising further functionality1340. The further functionality1340may comprise hardware or software necessary for the scheduling node12to perform different tasks that are not disclosed herein. Merely as an illustrative example, the further functionality may comprise a scheduler for scheduling transmissions from the scheduling node12and/or for transmissions from scheduled devices with which the scheduling node12communicates with.

FIG.14is a block diagram of the scheduling node12according to another exemplifying embodiment.FIG.14illustrates the scheduling node12comprising a determining unit1403, which could also be denoted an updating unit or adjusting unit etc., for determining and/or updating/adjusting at least one LBT parameter for the wireless device10.FIG.14illustrates the scheduling node12further comprising an information unit1404, which could also be denoted transmitting unit or notification unit etc., for informing concerned scheduled wireless device(s) about the determined/adjusted/updated LBT parameters to be used by the scheduled wireless device(s) hereinafter until further notice, e.g. until they are anew determined/adjusted/updated.

The determining unit1403may be configured to determine at least one LBT parameter associated with the LBT procedure.

The information unit1404may be configured to inform the wireless device10about the determined at least one LBT parameter in a scheduling grant of the uplink transmission.

The scheduling node12may comprise a scheduler1405. The scheduler may be configured to schedule the uplink transmission to a single subframe or a burst of subframes; and to add corresponding scheduling information to the scheduling grant.

The scheduler1405may be configured to schedule the uplink transmission by being configured to determine a delay between the joint grant transmission and the first uplink subframe and scheduling multiple uplink subframes using the joint grant transmission. The scheduler1405may then be configured to schedule the first uplink subframe based on the determined delay, and wherein the scheduler1405may be configured to determine the delay based on a downlink data buffer and schedule the number of uplink subframes by means of the joint grant based on the uplink buffer of the wireless device.

The information unit1404may be configured to inform the wireless device of the at least one LBT parameter by means of a common search space on the PDCCH or another downlink control channel.

The information unit1404may be configured to inform the wireless device of the at least one LBT parameter by means of broadcasting.

The information unit1404may be configured to signal, to the wireless device10, a maximum transmission duration.

The determining unit1403may be configured to determine the at least one LBT parameter by being configured to determine at least two different sets of LBT parameters for the wireless device10to be used by the wireless device10in successive LBT attempts. The determining unit1403may be configured to determine which set to be used by the wireless device10according to a predefined rule or predefined table and the information unit1404may be configured to signal which set to use to the wireless device10.

InFIG.14, the scheduling node12is also illustrated comprising a communication unit1401. Through this unit, the scheduling node12is adapted to communicate with other nodes, devices, UEs and/or entities in the wireless communication network. The communication unit1401may comprise more than one receiving arrangement. For example, the communication unit1401may be connected to both a wire and an antenna, by means of which the scheduling node12is enabled to communicate with other nodes, devices. UEs and/or entities in the wireless communication network. Similarly, the communication unit1401may comprise more than one transmitting arrangement, which in turn is connected to both a wire and an antenna, by means of which the scheduling node12is enabled to communicate with other nodes, devices, UEs and/or entities in the wireless communication network. The scheduling node12further comprises a memory1402for storing data. Further, the scheduling node12may comprise a control or processing unit (not shown) which in turn is connected to the different units1403-1404. It shall be pointed out that this is merely an illustrative example and the scheduling node12may comprise more, less or other units or modules which execute the functions of the scheduling node12in the same manner as the units illustrated inFIG.14.

It should be noted thatFIG.14merely illustrates various functional units in the scheduling node12in a logical sense. The functions in practice may be implemented using any suitable software and hardware means/circuits etc. Thus, the embodiments are generally not limited to the shown structures of the scheduling node12and the functional units. Hence, the previously described exemplary embodiments may be realised in many ways. For example, one embodiment includes a computer-readable medium having instructions stored thereon that are executable by the control or processing unit for executing method steps (according to the solution described herein by means of several examples and embodiments) in the scheduling node12. The instructions executable by the computing system and stored on the computer-readable medium perform the method steps of the scheduling node12according to the herein described embodiments and examples.

FIG.15schematically shows an embodiment of an arrangement1500in the scheduling node12. Comprised in the arrangement1500in the scheduling node12are here a processing unit1506, e.g. with a Digital Signal Processor. DSP. The processing unit1506may be a single unit or a plurality of units to perform different actions of procedures described herein. The arrangement1500of the scheduling node12may also comprise an input unit1502for receiving signals from other entities, and an output unit1504for providing signal(s) to other entities. The input unit and the output unit may be arranged as an integrated entity or as illustrated in the example ofFIG.14, as one or more interfaces1401.

Furthermore, the arrangement in the scheduling node12comprises at least one computer program product1508in the form of a non-volatile memory, e.g. an Electrically Erasable Programmable Read-Only Memory, EEPROM, a flash memory and a hard drive. The computer program product1508comprises a computer program1510, which comprises code means, which when executed in the processing unit1506in the arrangement1500in the scheduling node12causes the scheduling node12to perform the actions according to the solution as described herein by means of the various embodiments and examples.

The computer program1510may be configured as a computer program code structured in computer program modules1510a-1510e. Hence, in an exemplifying embodiment, the code means that the computer program of the scheduling node12comprises a determining unit, or module, for determining/adjusting/updating one or more LBT parameters. The computer program further comprises an informing unit, or module, for informing/transmitting/notifying a scheduled device about the determined/adjusted/updated one or more LBT parameters.

The computer program modules could essentially perform the actions of the solution as described, to emulate the determining/adjusting/updating one or more LBT parameters. In other words, when the different computer program modules are executed in the processing unit1506, they may correspond to the units1403-1404ofFIG.14.

Although the code means in the embodiments disclosed above in conjunction withFIG.14are implemented as computer program modules which when executed in the processing unit causes the scheduling node to perform the actions described above in the conjunction with figures mentioned above, at least one of the code means may in alternative embodiments be implemented at least partly as hardware circuits.

FIG.16is a block diagram depicting the wireless device10for performing the uplink transmission to the scheduling node12according to embodiments herein. The wireless device10is configured to connect to the Pcell of the scheduling node12in a licensed or unlicensed frequency band and the wireless device10is also configured to connect to at least one SCell in an unlicensed frequency band.

The wireless device10comprises a processing means1620, e.g. one or more processors, configured to perform the methods herein.

The wireless device10may comprise a receiving module1621. The wireless device10, the processing means1620and/or the receiving module1621may be configured to receive information, in the scheduling grant of the uplink transmission, of at least one LBT parameter associated with the LBT procedure.

The wireless device10may comprise a performing module1622. The wireless device10, the processing means1620and/or the performing module1622may be configured to perform the LBT procedure using the at least one LBT parameter when transmitting data according to the received scheduling grant.

The wireless device10, the processing means1620and/or the receiving module1621may be configured to receive the information by means of the common search space on the PDCCH or another downlink control channel, or receive the information in a broadcast.

The wireless device10, the processing means1620and/or the receiving module1621may be configured to receive, from the scheduling node12, the maximum transmission duration.

The wireless device10, the processing means1620and/or the receiving module1621may be configured to further receive from the scheduling node12, configuring information indicating different sets of LBT parameters.

The wireless device10, the processing means1620and/or the performing module1622may be configured to change the at least one LBT parameter in consecutive LBT attempts for a particular transmission burst based on pre-defined rules, or pre-defined tables.

The wireless device10, the processing means1620and/or the receiving module1621may be configured to further receive information that indicates which set to use, with the further information received via higher layer signalling or L1 signalling.

The wireless device10, the processing means1620and/or the performing module1622may be configured to use a default set and only change the set when signalled to do so by RRC signalling or L1 signalling.

The wireless device10may comprise a resetting module1623. The wireless device10, the processing means1620and/or the resetting module1623may, when the at least one LBT parameter comprises the CW size, be configured to reset the CW size to a minimum value if some conditions are met.

The methods according to the embodiments described herein for the wireless device are respectively implemented by means of e.g. a computer program1611or a computer program product, comprising instructions, i.e., software code portions, which, when executed on at least one processor, cause the at least one processor to carry out the actions described herein, as performed by the wireless device. The computer program1611may be stored on a computer-readable storage medium1612. e.g. a disc or similar. The computer-readable storage medium1612, having stored thereon the computer program, may comprise the instructions which, when executed on at least one processor, cause the at least one processor to carry out the actions described herein, as performed by the wireless device10. In some embodiments, the computer-readable storage medium may be a non-transitory computer-readable storage medium.

The wireless device10further comprises a memory1610, communication unit1630and further functionality1640. The memory comprises one or more units to be used to store data on, such as LBT parameters, scheduled resources, grants, transmit power, applications to perform the methods disclosed herein when being executed, and similar.

The processor may be a single Central Processing Unit. CPU, but could also comprise two or more processing units. For example, the processor may include general purpose microprocessors; instruction set processors and/or related chips sets and/or special purpose microprocessors such as Application Specific Integrated Circuits, ASICs. The processor may also comprise board memory for caching purposes. The computer program may be carried by a computer program product connected to the processor. The computer program product may comprise a computer readable medium on which the computer program is stored. For example, the computer program product may be a flash memory, a Random-Access Memory RAM, Read-Only Memory, ROM, or an EEPROM, and the computer program modules described above could in alternative embodiments be distributed on different computer program products in the form of memories within the scheduling node.

It is to be understood that the choice of interacting units, as well as the naming of the units within this disclosure are only for exemplifying purpose, and nodes suitable to execute any of the methods described above may be configured in a plurality of alternative ways in order to be able to execute the suggested procedure actions.

It should also be noted that the units described in this disclosure are to be regarded as logical entities and not with necessity as separate physical entities.

According to an aspect a method performed by a scheduling node is provided for scheduling an uplink transmission from a wireless devices to the scheduling node. The scheduling node and the wireless device may support carrier aggregation, wherein the wireless device may be associated with the scheduling node by means of being connected to a Primary Cell, Pcell, in a licensed or unlicensed frequency band, the wireless device may also be connected to at least one Secondary Cell, SCell, in an unlicensed frequency band. The wireless device may also in this disclosure be referred to as a scheduled device, a UE, a device to be scheduled and/or a terminal.

The method may comprise determining/updating/adjusting at least one LBT parameter associated with a LBT procedure. The method may also comprise informing the wireless device about the determined/updated at least one LBT parameter.

In an example, the at least one LBT parameter is specific for the wireless device.

In another example, the at least one LBT parameter is common for a plurality of wireless devices that are associated with the scheduling node12.

In yet another example, the scheduling node12may inform the wireless device of the determined/updated/adjusted at least one LBT parameter e.g. by means of a Downlink Control Information. DCI, of the scheduling grant.

In an example, the scheduling grant may comprise LBT parameter(s) relating to a single subframe or a burst of subframes.

In a further example, the single subframe or burst of subframes is to be transmitted on a single channel or across multiple channels.

Further, in an example, the scheduling node informs the device of the determined/updated at least one LBT parameter by means of a common search space on the Physical Downlink Control Channel, PDCCH, or another downlink control channel.

Still further, in another example, the scheduling node informs the device of the determined/updated at least one LBT parameter by means of broadcasting.

In an example, the method may further comprise signalling, to the device, a maximum transmission duration.

In another example, the method may further comprise determining a delay between a joint grant transmission and a first uplink subframe and scheduling multiple uplink subframes using the joint grant transmission, wherein the first uplink subframe is scheduled based on the determined delay.

In yet an example, the delay may be determined based on a downlink data buffer.

In a further example, the number of uplink subframes scheduled by means of the joint grant may be based on the uplink buffer of the device.

Further, in an example, determining/updating at least one LBT parameter may comprise determining at least two different sets of LBT parameters for the device to be used by the device in successive LBT attempts.

In yet an example, which set to be used by the device may be determined according to a predefined rule or predefined table.

In still another example, which set to be used by the device is signalled to the device.

Further, in an example, the at least one LBT parameter is one of, but not limited to, Contention Window (CW) size, length of defer period, random backoff counter, length of initial Clear Channel Assessment (CCA), duration of quick CCAs on channels other than the principal random backoff channel, rate of CW size adaptation, triggers to adapt CW size.

In yet an example, the determined/updated at least one LBT parameter may be the actual/absolute value of the LBT parameter(s) or an offset/differential to be added/subtracted to the current value of the LBT parameter(s).

The solution may have several advantages. One possible advantage is that the use of suboptimal LBT parameters at one or more devices may be avoided and their channel access probability may be improved. Yet another possible advantage is that successful multiplexing of multiple devices on the same uplink subframe on the same unlicensed band is enabled. Still another possible advantage is that improved coexistence between LAA/standalone LTE-U and WiFi in multi-carrier deployments is enabled. A further possible advantage is that improved coexistence between LAA/standalone LTE-U networks of different operators is enabled.

While the embodiments have been described in terms of several examples and embodiments, it is contemplated that alternatives, modifications, permutations and equivalents thereof may become apparent upon reading of the specifications and study of the drawings. Instead, the embodiments herein are limited only by the following claims and their legal equivalents.