CN111357210B

CN111357210B - Processing equipment and method thereof

Info

Publication number: CN111357210B
Application number: CN201780096956.8A
Authority: CN
Inventors: 本特·林多夫; 柴塔尼亚·图木拉; 王能
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2017-11-16
Filing date: 2017-11-16
Publication date: 2022-02-01
Anticipated expiration: 2037-11-16
Also published as: WO2019096395A1; CN111357210A

Abstract

The invention relates to a processing device (100) for a client device (300). The processing device (100) determines that a random access, RA, procedure needs to be performed when in a connected state with a network access node (400) using a downlink serving beam (502). The processing device (100) further obtains RA parameters for the RA procedure, wherein the RA parameters indicate at least one RA resource and at least one RA preamble. The processing device (100) further selects an uplink beam (512) of the RA procedure according to a quasi co-location association with a reference signal resource received on a downlink beam from the network access node (400), and transmits the RA preamble in the RA resource to the network access node (400) through the selected uplink beam (512) to initiate the RA procedure. Furthermore, the invention relates to a client device (300), a corresponding method and a computer program product.

Description

Processing equipment and method thereof

Technical Field

The present invention relates to a processing apparatus. Furthermore, the invention relates to a client device comprising the processing device, a corresponding method and a computer program.

Background

The 5G cellular system is also called New Radio (NR), and its standard is currently in the establishment. NR is for the radio spectrum from below 1GHz to above 60 GHz. To achieve such a diversified wireless environment, it is necessary to support not only different system bandwidths but also different parameter sets, for example, different subcarrier spacing (SCS). In addition, for carriers exceeding 10GHz, multiple antennas and beamforming techniques are needed to combat the higher path loss associated with such high radio frequencies.

When beamforming is used, a next generation base station (gNB) transmits data in multiple directions through different transmit beams. Therefore, a User Equipment (UE) needs to adjust its receive antennas in different receive beam directions to communicate with the gNB. In order for the UE to be able to detect and track the transmit beam of the gNB, the UE needs to perform beam monitoring. Thus, the gNB transmits known pilot signals on adjacent beams, which the UE receives and uses to detect possible transmit beams to switch to when the radio environment changes. The principle of beam monitoring can be analogized to cell search in traditional Long Term Evolution (LTE), Wideband Code Division Multiple Access (WCDMA) and High Speed Packet Access (HSPA) systems. In these systems, the UE needs to periodically scan for neighboring cells to find possible handover candidates.

Each possible connection between a UE and a gNB is called a Beam Pair Link (BPL), where the BPL consists of a pair of best matching transmit and receive beams. The gNB configures a set of BPLs for UE monitoring. The configured set of detected BPLs may be determined according to which BPLs were detected by the UE. For example, the set may include all BPLs associated with control and data channels between the gNB and the UE. The gNB may also configure a set of serving BPLs for transmitting control information associated with the serving BPLs to the UE. Wherein the service BPL set is a subset of the monitoring BPL set or itself. The UE monitors the quality of the monitored BPL set and reports to the gNB via a beam measurement report. When a beam monitoring the BPL becomes stronger than the current serving BPL, a beam switch may be initiated. The NR standard has not defined an explicit procedure for beam switching. One approach may be for the UE to trigger a beam measurement report containing an event that the target BPL is stronger than the current serving BPL. In another scenario, for example, the gNB determines that the target BPL has become the appropriate serving BPL through an upstream management process. The gNB may then initiate a beam switch to the target BPL.

Under the scenario that the UE gives up the service BPL due to rotation or shielding of the UE, and the quality of all downlink service BPLs is lower than the predetermined quality, the UE declares a beam failure and starts a beam recovery procedure. The UE performs a beam recovery procedure in an attempt to recover from the beam failure. To monitor the quality of the serving BPL and the candidate BPLs, the UE may be configured to monitor either a Synchronization Signal Block (SSB) or CSI-RS that is quasi co-located with the control channel hypothesis on the respective BPL.

In NR, the beam recovery procedure involves a Random Access (RA) procedure. The main purpose of the RA procedure is to achieve uplink synchronization between the UE and the network access node. The RA procedure is also used for other scenarios where the UE is not synchronized with the network, e.g. initial access. The standardization of the RA procedure in NR is not yet complete and the NR standardization group is currently discussing the details of how the RA procedure is performed in different scenarios.

Disclosure of Invention

It is an aim of embodiments of the present invention to provide a solution to alleviate or solve the disadvantages and problems of conventional solutions.

The above and other objects are achieved by the subject matter of the independent claims. Further advantageous embodiments of the invention can be found in the dependent claims.

According to a first aspect of the present invention, the above and other objects are achieved by a processing device for a client device, the processing device being adapted to:

when the network access node using the downlink service beam is in a connected state, determining that a Random Access (RA) process needs to be executed;

obtaining RA parameters of the RA procedure, wherein the RA parameters indicate at least one RA resource and at least one RA preamble;

selecting an uplink beam of the RA procedure according to a quasi co-location association with a reference signal resource received on a downlink beam from the network access node;

transmitting the RA preamble in the RA resource to the network access node through the selected uplink beam to initiate the RA procedure.

The need to perform the RA procedure may refer to the processing device not being able to receive a response from the network access node when it is currently transmitting upstream and the processing device determining that upstream communication is needed by other means, such as performing the RA procedure described herein.

In this disclosure, being in a connected state with a network access node using a downlink service beam may refer to the processing device or a client device including the processing device being in a state capable of communicating with the network access node through the downlink service beam. The connected state may be, for example, an RRC connected state, or other state in which the network access node is aware of the client device that contains the processing device.

In this disclosure, selecting an uplink beam of the RA procedure according to a quasi-co-located association with a reference signal resource received on a downlink beam from the network access node may be understood as selecting an uplink beam in the same direction as the downlink beam transmitting the reference signal resource. Thus, from the perspective of the client device, the selected uplink beam has the same direction of view as the downlink beam transmitting the reference signal resource. Furthermore, reference signals and control channels are quasi co-located, which is understood to mean that reference signals and control channels are transmitted and/or received in the same direction, e.g. on the same uplink beam and/or on the same downlink beam. Further, the downlink beam for transmitting the reference signal resource may be a downlink service beam or a non-downlink service beam.

In this disclosure, the terms "uplink beam" and "downlink beam" are used to describe the direction of transmission of signals and the direction of reception of signals, respectively, for a client device. Thus, a particular beam may be interpreted as a certain spatial parameter setting or spatial filtering determined in the processing device. For example, these settings or parameters may be output by the processing device and used in the configuration of a client device wireless transceiver to send or receive signals in a particular direction.

Furthermore, the term "beam failure" may be interpreted as an indication made by the processing device based on a radio link quality assessment to initiate a beam recovery procedure or, more generally, to initiate a (radio) link reconfiguration, wherein a radio link here refers to a wireless communication link between a client device comprising the processing device and a network access node.

The advantage of the processing device is that it knows which RA parameters and uplink beams to use when RA procedures need to be performed. Thereby, the client device comprising the processing device is aligned with the network access node and resynchronization with the network access node can be achieved faster than with procedures known in the art.

In an implementation form of the processing device according to the first aspect, the reference signal resource is a channel state information reference signal (CSI-RS) resource configured for the communication device.

An advantage of this implementation form is that the processing device may determine which uplink beams are available for performing the RA procedure based on a quasi co-located association with CSI-RS resources. Thereby achieving faster resynchronization.

In an implementation form of the processing device according to the first aspect, the CSI-RS resources are received on the downlink serving beam.

This means that in this embodiment, the processing device may select an uplink serving beam in the same direction as a downlink serving beam transmitting the reference signal resource. Therefore, the quasi co-location association may be employed due to the correspondence between the transmit beams and the receive beams. In other words, from the perspective of the client device, the look direction of the uplink service beam is the same as the look direction of the downlink service beam.

This embodiment has the advantage that the uplink service beam can be selected. When the RA procedure is performed using the uplink serving beam, the search time required for RA by the RA detector in the network access node is shorter, and thus faster recovery can be achieved.

In an implementation form of the processing device according to the first aspect, the reference signal resource is a Synchronization Signal Block (SSB) resource.

An advantage of this implementation form is that the processing device may determine which uplink beams are available for performing the RA procedure based on a quasi co-located association with SSB resources.

In an implementation form of the processing device according to the first aspect, the SSB resources are received on the downlink serving beam.

In an implementation form of the processing device according to the first aspect, the processing device is further configured to:

acquiring a threshold corresponding to the channel quality index;

determining a channel quality for each of a plurality of reference signal resources received on a corresponding plurality of downlink beams;

selecting the reference signal resource from the plurality of reference signal resources according to the threshold and channel qualities of the plurality of reference signal resources.

The selected reference signal resource is the same as the reference signal resource selected by the processing device of the first aspect.

This embodiment has the advantage that the channel quality of the uplink beam of the RA procedure selected by the processing device is sufficiently good. Thereby making the RA detection in the network access node more reliable.

and determining that an RA flow needs to be executed according to an event triggered in the uplink transmission process.

This embodiment has the advantage that the processing device determines that the uplink transmission procedure has failed and needs to perform an RA procedure in order to continue communicating with the network access node. Thereby, a faster recovery of the communication link is achieved.

In an implementation form of the processing device according to the first aspect, the event triggered by the uplink transmission procedure is at least one of: the transmission times of the scheduling request reach the maximum value; the time alignment timer has timed out; and a medium access control reset procedure.

This embodiment has the advantage that the processing device determines the type of the failed uplink transmission procedure and needs to perform an RA procedure in order to continue communicating with the network access node. Thereby, a faster recovery of the communication link is achieved.

In an implementation form of the processing device according to the first aspect, at least one of the RA resource and the RA preamble is associated with a reference signal resource received on the downlink beam.

This implementation form has the advantage that the one-to-one mapping between the used RA parameters and the uplink beams used for transmitting preambles may make RA detection in the network access node simpler.

determining a beam failure status of the downlink serving beam prior to transmitting the RA preamble in the RA resource.

This embodiment has the advantage that the processing device can perceive the beam fault state. Thus, resynchronization with the network access node may be achieved more quickly.

if the beam fault state of the downlink service beam is determined to be a fault state, suspending the RA process;

and if the beam fault state of the downlink service beam is determined to be the fault state, initiating a beam fault recovery process.

This embodiment has the advantage that the processing device knows by which access procedure to reestablish a connection to the network access node. Therefore, the link can be quickly reconnected, and the user experience is improved.

determining a beam fault status of the downlink service beam according to a predefined beam monitoring procedure.

This embodiment has the advantage that the processing device knows how to monitor for beam faults, which means that the processing device can detect beam fault conditions more quickly. Resynchronization with the network access node is thereby achieved more quickly.

determining a beam fault status of the downlink serving beam according to the predefined beam monitoring procedure based on an assumed error rate associated with a control channel, wherein the control channel is quasi co-located with reference signal resources transmitted by the downlink beam.

This embodiment has the advantage that the processing device uses a well-defined beam monitoring procedure in order to determine possible beam fault states in a consistent manner. This improves the overall reliability of the wireless communication system.

the RA procedure is performed in a Discontinuous Reception (DRX) connected state.

This embodiment has the advantage that the processing device can operate in a power saving mode in the connected state and still perform a low latency RA preamble transmission.

According to a second aspect of the present invention, the above and other objects are achieved by a client device for a wireless communication system, comprising a processing device according to any implementation form of the processing device of the first aspect.

The client device has the advantage that it is aligned with the network access node and that resynchronization with the network access node can be achieved faster than with procedures known in the art.

According to a third aspect of the present invention, the above and other objects are fulfilled by a method for a processing device, the method comprising:

The method according to the third aspect may be extended to an implementation form corresponding to the implementation form of the processing device according to the first aspect. Embodiments of the method therefore include the features of the corresponding embodiments of the treatment device.

The advantages of the method according to the third aspect are the same as the advantages of the corresponding embodiment of the treatment apparatus according to the first aspect.

The invention also relates to a computer program characterized in that it comprises code means which, when run by processing means, causes said processing means to execute any of the methods provided by the invention. Further, the invention also relates to a computer program product comprising a computer readable medium and the aforementioned computer program, wherein the computer program is contained in the computer readable medium and the computer readable medium comprises one or more of the following: ROM (read only memory), PROM (programmable ROM), EPROM (erasable PROM), flash memory, EEPROM (electrically EPROM), and hard disk drives.

Other applications and advantages of the present invention will become apparent from the following detailed description.

Drawings

The accompanying drawings are included to illustrate and explain various embodiments of the present invention, in which:

FIG. 1 illustrates a processing device provided by an embodiment of the invention;

FIG. 2 illustrates a method provided by an embodiment of the invention;

FIG. 3 illustrates a client device provided by an embodiment of the invention;

fig. 4 illustrates a wireless communication system provided by an embodiment of the present invention;

FIG. 5 illustrates a flow chart of a method provided by an embodiment of the present invention;

fig. 6 illustrates a process for determining a beam fault condition provided by an embodiment of the present invention.

Detailed Description

Fig. 1 illustrates a processing device 100 provided by an embodiment of the present invention. In the embodiment shown in fig. 1, the processing device 100 includes at least one processor core 102, and the processor core 102 may be coupled to an internal or external memory 104 by a coupling/communication means 106 known in the art. The processing device may also include a plurality of processor cores 102. Memory 104 may store program code for processor cores 102 of processing device 100 to perform the actions described herein. The processing apparatus 100 further includes an input member 108 and an output member 110, the input member 108 and the output member 110 each coupled to the processor core 102 by a coupling/communication means 106 known in the art.

In this disclosure, the processing device 100 is configured to perform certain actions it should be understood that the processing device 100 includes suitable means, such as the processor core 102, for performing the actions. The processing device 100 may be, for example, a baseband processor with a memory 104 for use in a client device of a mobile communication network.

The processing device 100 is configured to determine that a Random Access (RA) procedure needs to be performed when in a connected state with a network Access node 400 using a downlink service beam 502 (as shown in fig. 4). The processing device 100 is further configured to obtain an RA parameter of the RA procedure. The RA parameters indicate at least one RA resource and at least one RA preamble. The processing device 100 is further configured to select an uplink beam 512 (shown in fig. 4) of the RA procedure based on a quasi co-located association with reference signal resources received on a downlink beam from the network access node 400. Furthermore, the processing device 100 is configured to send the RA preamble in the RA resource to the network access node 400 over the selected uplink beam 512 to initiate (start) the RA procedure.

Fig. 2 shows a flow diagram of a corresponding method 200, which may be performed by processing device 100, such as processing device 100 shown in fig. 1. The method 200 comprises the following steps: (202) when in a connected state with the network access node 400 using the downlink service beam 502, it is determined that an RA procedure needs to be performed. The method 200 further comprises: (204) and obtaining the RA parameter of the RA process. The RA parameters indicate at least one RA resource and at least one RA preamble. The method 200 further comprises: (206) the uplink beam 512 of the RA procedure is selected according to a quasi co-located association with reference signal resources received on a downlink beam from the network access node 400. Further, the method 200 comprises: (208) transmitting the RA preamble in the RA resource to the network access node 400 over the selected uplink beam 512 to initiate the RA procedure.

The processing device 100 may be comprised in a client device, e.g. the client device 300 shown in fig. 3, e.g. as a baseband processor. In the embodiment shown in fig. 3, the client device 300 includes the processing device 100 and a transceiver/modem 302. The processing device 100 is coupled to the transceiver 302 by a communication means 304 as is known in the art. The client device 300 further comprises an antenna or antenna array 306 coupled to the transceiver 302, which means that the client device 300 is used for wireless communication in a wireless communication system.

Fig. 4 illustrates a wireless communication system 500 provided by an implementation. The wireless communication system 500 comprises a client device 300 and a network access node 400, both for operating in the wireless communication system 500. The client device 300 includes a processing device 100. For simplicity of description, the wireless communication system 500 shown in fig. 4 includes only one client device 300 and one network access node 400. However, the wireless communication system 500 may include any number of client devices 300 and any number of network access nodes 400 without departing from the scope of the present invention.

In the wireless communication system 500, beamforming techniques are used such that data is transmitted in multiple directions through different downlink and uplink beams between the client device 300 and the network access node 400. In fig. 4, three

downlink beams

502, 504, 506 and two

uplink beams

512, 514 are shown. However, any number of uplink and/or downlink beams may exist between the client device 300 and the network access node 400 without departing from the scope of the present invention. In fig. 4, the client device 300 is in a connected state with the network access node 400 using the downlink beam 502 as the downlink service beam and the uplink beam 512 as the uplink service beam. Further, the client device 300 may receive reference signal resources from the network access node 400 on the downlink beams 502, 504, 506. The received reference signal resources may be used by the client device 300 to evaluate the quality of the downlink beams 502, 504, 506 and to select an appropriate downlink serving beam. In this embodiment of the present invention, the reference signal resource may be a channel state information reference signal (CSI-RS) resource configured by the network access node 400 for the client device 300. The CSI-RS resources may be received on downlink serving beam 502. Alternatively, the reference signal resource may be a Synchronization Signal Block (SSB) resource. At this point, SSB resources may be received on downlink service beam 502. As described previously, the client device 300 may select an uplink beam for an RA procedure using the received reference signal resources.

According to the embodiment of the present invention, the determination that the RA procedure needs to be performed may be triggered by an indication of an uplink transmission procedure. The uplink transmission procedure may be a Scheduling Request (SR) procedure or a procedure for performing uplink transmission without uplink grant, for example, configured semi-persistent scheduling. Fig. 5 is a flow chart illustrating a method 600 for determining that an RA procedure needs to be performed and performing the RA procedure according to an embodiment of the present invention. The method 600 shown in fig. 5 may be performed by the processing device 100. In the present embodiment, the processing device 100 is included in a client device 300. It is assumed that the processing device 100 or the client device 300 is in a connected state with the network access node 400 using the downlink service beam 502. The method 600 begins at step 602 with the processing device 100 determining that an RA procedure needs to be performed. The processing device 100 may determine that the RA procedure needs to be executed according to an event triggered by the uplink transmission procedure. The event triggered by the uplink transmission process is at least one of the following events: the transmission times of the scheduling request reach the maximum value; the time alignment timer has timed out; and a Medium Access Control (MAC) reset procedure.

An event that the number of transmissions of a scheduling request has reached a maximum value may be triggered, for example, in the following scenario: the network access node 400 has a heavy uplink load and cannot provide resources for uplink transmission of the client device 300, or the client device 300 has disconnected from an uplink or downlink connection with the network access node 400. The event that the time alignment timer times out is related to the timing advance, meaning that the uplink transmission timing may no longer be correct and therefore the client device may have lost uplink synchronization. Furthermore, an event in which a MAC reset procedure occurs may be triggered, for example, in the event that semi-persistent scheduling resources are cancelled.

If processing device 100 determines in step 602 that an RA procedure needs to be performed, processing device 100 performs step 604. In step 604, the processing device 100 obtains RA parameters for performing the RA procedure. The RA parameters indicate at least one RA resource, e.g., time and/or frequency resource, and at least one RA preamble, e.g., preamble signature. Furthermore, in an embodiment of the present invention, at least one of the RA resource and the RA preamble may be associated with a reference signal resource received on a downlink beam. Thus, different downlink beams associated with different reference signal resources may have different sets of RA parameters. Taking the reference signal resource as an SSB resource for example, this means that a first SSB resource transmitted on a first downlink beam may be associated with a first RA parameter, a second SSB resource transmitted on a second downlink beam may be associated with a second RA parameter, and so on. Therefore, if an uplink beam is selected in step 606 (which will be described below), based on the first SSB resource received on the first downlink beam, the processing device 100 obtains the first RA parameter according to the association between the first SSB resource and the first RA parameter.

In addition to obtaining the RA parameter, processing device 100 selects an uplink beam for the RA procedure in step 606. As shown in fig. 5, step 606 is performed after step 604. However, step 606 may also be performed before step 604, or may also be performed at least partially in parallel with step 604. The uplink beam of the RA procedure is selected according to a quasi co-located association with reference signal resources received on the downlink beam from the network access node 400. This means that the processing device 100 may select an uplink beam in the same direction as the processing device 100 receives the downlink beam of the reference signal resource. As an example, the spatial filtering for the uplink RA procedure may be the same as the spatial filtering for receiving the reference signal resources. As mentioned above, the reference signal resource may be, for example, a CSI-RS resource or an SSB resource. Thus, the quasi-co-located association may be an association with a CSI-RS resource configured for client device 300, or an association with an SSB resource. The quasi co-location association may be employed due to the correspondence between the transmit beams and the receive beams. When the client device 300 determines a downlink beam based on, for example, an association with a CSI-RS transmission, the client device 300 knows which transmit beam the network access node 400 specifically uses and which receive beam it specifically uses in the downlink. Thus, the client device 300 may use the particular receive beam as the transmit beam and know that the network access node 400 will receive the information. In other words, from the perspective of the client device 300, the look direction of the uplink service beam is the same as the look direction of the downlink service beam.

The selection of the uplink beam in step 606 of fig. 5 may also be based on the channel quality of each received reference signal resource. In this case, the processing device 100 may obtain a threshold corresponding to the channel quality indicator, and may further determine the channel quality of each of the plurality of reference signal resources received on the corresponding plurality of downlink beams. The processing device 100 further selects the reference signal resource from the plurality of reference signal resources according to the threshold and channel qualities of the plurality of reference signal resources. By the method, the uplink beam with better channel quality can be selected, so that the success chance of the RA process is improved.

Some specific examples are given below to describe how, when the processing device 100 is included in the client device 300 shown in fig. 4, the processing device 100 selects an uplink beam of the RA procedure in step 606 in fig. 5:

a) the processing device 100 may select the uplink beam through quasi-co-location association of CSI-RSs configured for the client device 300, where the uplink beam may also be the uplink serving beam 512 associated with the downlink serving beam 502.

b) Processing device 100 may select an uplink beam through quasi co-located association of SSBs. Since there may be multiple downlink beams associated with different SSBs, the processing device 100 may select the uplink beams 512, 514 associated with the downlink beams 502, 504, 506 having a quality above a threshold.

c) Processing device 100 may select an uplink beam through quasi co-located association of SSBs. Further, the selected uplink beam 512 is quasi co-located with the uplink serving beam 502. At this time, the client device 300 selects an uplink beam 512 corresponding to the downlink service beam 502, and the downlink service beam 502 is also a downlink beam for SSB.

d) Processing device 100 may select uplink beam 512 corresponding to downlink serving beam 502 or select uplink beam 514 corresponding to downlink beam 504 associated with the SSB even if the CSI-RS is configured for downlink serving beam 502.

In step 608, the processing device 100 initiates an RA procedure through the obtained RA parameter and the selected uplink beam. Thus, the processing device 100 sends the RA preamble in the RA resource to the network access node 400 through the selected uplink beam. This includes, for example, sending the RA preamble to a lower layer for transmission over the wireless link. According to an embodiment of the present invention, the connection state of the processing device 100 may be a Discontinuous Reception (DRX) connection state. In these embodiments, therefore, while in DRX connected state, processing device 100 may initiate an RA procedure in step 608.

In some embodiments of the present invention, the client device 300 may determine the beam failure status of the downlink service beam before performing the RA procedure, as shown in fig. 5, and step 610 is an optional step. In step 610, before transmitting the RA preamble in the RA resource, the processing device 100 determines a beam failure status of the downlink serving beam 502, that is, determines whether the downlink serving beam 502 is reliable. The beam fault status of the downlink service beam 502 may be determined according to a beam monitoring process. For example, processing device 100 may determine a beam fault status for downlink serving beam 502 according to a predefined beam monitoring procedure. The predefined beam monitoring procedure may be based on link quality measurements on reference signal resources transmitted on the downlink serving beam 502, the link quality corresponding to a hypothesized error rate associated with a control channel that is quasi co-located with the reference signal resources transmitted on the downlink serving beam 502. If the link quality is below a configured threshold, the downlink serving beam 502 is in a failed state, otherwise it is not in a failed state.

If it is determined that the beam failure status of the downlink serving beam 502 is a failure status, that is, the determination result in step 610 is yes, the processing device 100 may suspend the RA procedure and initiate a beam failure recovery procedure, as shown in step 612 in fig. 5. The beam failure recovery process may be performed according to a beam recovery process known in the art.

On the other hand, if it is determined that the beam failure status of the downlink service beam 502 is not the failure status, i.e., the determination in step 610 is no, the processing device 100 will jump to step 604 in fig. 5 and execute step 604, step 606 and step 608, as described above. Thus, the processing device 100 will obtain the RA parameter, select the uplink beam, and further initiate an RA procedure according to the obtained RA parameter and the selected uplink beam.

Embodiments of determining the beam failure state of the downlink serving beam may be used, for example, when the client device 300 is in a DRX connected state. Fig. 6 illustrates an application of this embodiment and illustrates the timing at which a client device 300 in a DRX connected state can determine a beam failure state for a downlink serving beam 502. In the example shown in fig. 6, the reference signal resources are transmitted on the downlink service beam 502 every 20 milliseconds, as indicated by the black bars in fig. 6. Further, the duration ON of the client device 300 itself occurs once every 100 milliseconds. During the duration ON, the ue 300 performs a beam monitoring procedure, i.e. measuring the link quality ON the reference signal resources transmitted ON the downlink serving beam 502. Thus, during each duration ON, the client device 300 may determine a beam failure state for the downlink service beam 502. However, according to the embodiment of the present invention, the beam monitoring procedure may be additionally performed once in the scheduling request procedure or in the case of a scheduling request failure. Fig. 6 shows a scheduling request procedure SRP comprising four scheduling request SR attempts. During the scheduling request procedure SRP, the client device 300 is in an on state, and thus a beam monitoring procedure may be additionally performed once to determine a beam failure state of the downlink service beam 502. Furthermore, if the scheduling request procedure SRP is unsuccessful, the client device 300 may perform additional beam monitoring immediately after the scheduling request failureWithout waiting for the next duration ON. The additional beam monitoring procedure may be an additional duration ON after the scheduling request procedure SRP_addWhile it is performed as shown in fig. 6. In this way, the client device 300 may determine the beam failure status of the downlink service beam 502 before needing to perform the RA procedure triggered by the scheduling request failure. Accordingly, client device 300 may perform the RA procedure only upon determining that the beam failure status of the downlink service beam 502 is not a failure status, as described above with respect to fig. 5. Thus, system resources are saved and power consumption of the client device 300 is reduced.

The client device 300 herein may refer to a User Equipment (UE), a mobile station, an internet of things (IoT) device, a sensor device, a wireless terminal and/or a mobile terminal, which is capable of wireless communication in a wireless communication system (also sometimes referred to as a cellular wireless system). The UE may also be referred to as a mobile phone, a cellular phone, a tablet, or a laptop computer with wireless capabilities. A UE herein may be, for example, a portable, pocket, hand-held, computer-included, or vehicle-mounted mobile device capable of voice and/or data communication with other entities, such as other receivers or servers, via a radio access network. The UE may be a Station (STA), which is any device including Media Access Control (MAC) and Physical Layer (PHY) interfaces in compliance with IEEE 802.11 standards for connecting Wireless Media (WM). The UE may also be used for communication in the fifth generation wireless technologies such as LTE and LTE-Advanced, WiMAX and their evolution systems related to 3GPP, and new air interface.

The network access node 400 may also be referred to herein as a wireless network access node, an access point or a Base Station, e.g., a Radio Base Station (RBS). In some networks, a base station may be referred to as a transmitter, "eNB", "eNodeB", "NodeB" or "B node (B node)", depending on the technology and terminology used. The radio network access nodes may be classified into different types according to transmission power and the size of a cell, for example, a macro base station (macro eNodeB), a home eNodeB (home eNodeB), or a pico base station (pico base station). A Wireless network Access node may be a Station (STA), which is any device that contains Media Access Control (MAC) and Physical Layer (PHY) interfaces in compliance with the IEEE 802.11 standard for connecting to the Wireless Medium (WM). The wireless network access node may also be a base station corresponding to a fifth generation (5G) wireless system.

In addition, any of the methods according to embodiments of the present invention may be implemented in a computer program having code means which, when run by a processing arrangement, causes the processing arrangement to perform the method steps. The computer program is embodied in a computer-readable medium of a computer program product. The computer-readable medium may include substantially any memory, such as ROM (read only memory), PROM (programmable ROM), EPROM (erasable PROM), flash memory, EEPROM (electrically EPROM), and a hard disk drive.

Furthermore, those skilled in the art realize that embodiments of the client device 300 and the network access node 400 comprise the communication capabilities necessary for performing the present solution in the form of functions, means, units, elements, etc. Examples of other such means, units, elements and functions are: processors, memories, buffers, control logic, encoders, decoders, rate matchers, de-rate matchers, mapping units, multipliers, decision units, selection units, switches, interleavers, de-interleavers, modulators, demodulators, inputs, outputs, antennas, amplifiers, receiving units, transmitting units, DSPs, MSDs, TCM encoders, TCM decoders, power supply units, power feeders, communication interfaces, communication protocols, etc., arranged together in a suitable manner to perform the present solution.

In particular, the processors of client device 300 and network access node 400 may include one or more examples of a Central Processing Unit (CPU), a Processing Unit, Processing circuitry, a processor, an Application Specific Integrated Circuit (ASIC), a microprocessor, or other Processing logic that may interpret and execute instructions. The term "processor" may thus refer to a processing circuit that includes a plurality of processing circuits, examples of which are any, some, or all of the items listed above. The processing circuitry may further perform data processing functions, inputting, outputting, and processing data, including data buffering and device control functions, such as call processing control, user interface control, and the like.

Finally, it is to be understood that the invention is not limited to the embodiments described above, but relates to and incorporates all embodiments within the scope of the appended independent claims.

Claims

1. A processing device (100) for a client device (300), characterized in that the processing device (100)

Comprising a processor core, an input member and an output member for:

determining that a random access, RA, procedure needs to be performed when in a connected state with a network access node (400) using a downlink serving beam (502);

selecting an uplink beam (512) of the RA procedure according to a quasi co-located association with reference signal resources received on a downlink beam from the network access node (400);

transmitting the RA preamble in the RA resources to the network access node (400) over the selected uplink beam (512) to initiate the RA procedure;

at least one of the RA resource and RA preamble is associated with a reference signal resource received on the downlink beam;

determining a beam failure status of the downlink serving beam (502) by performing a beam monitoring procedure during a scheduling request procedure prior to transmission of the RA preamble in the RA resource or upon a scheduling request failure.

2. The processing device (100) according to claim 1, wherein the reference signal resource is a channel state information reference signal, CSI-RS, resource configured for the processing device (100).

3. The processing device (100) according to claim 2, wherein the CSI-RS resources are received on the downlink serving beam (502).

4. The processing device (100) according to claim 3, wherein the reference signal resources are synchronization signal block, SSB, resources.

5. The processing device (100) according to claim 4, wherein the SSB resources are received on the downlink serving beam (502).

6. The processing apparatus (100) according to claim 5, configured to:

acquiring a threshold corresponding to the channel quality index;

7. The processing apparatus (100) according to claim 6, configured to:

8. The processing device (100) according to claim 7, wherein the uplink transmission procedure triggered event is at least one of: the transmission times of the scheduling request reach the maximum value; the time alignment timer has timed out; and a medium access control reset procedure.

9. The processing apparatus (100) according to claim 1, configured to:

suspending the RA procedure if the beam failure status of the downlink serving beam (502) is determined to be a failure status;

10. The processing apparatus (100) according to claim 9, configured to:

determining a beam failure status of the downlink serving beam (502) according to a predefined beam monitoring procedure.

11. The processing apparatus (100) according to claim 10, configured to:

determining a beam failure status of the downlink serving beam (502) according to the predefined beam monitoring procedure based on an assumed error rate associated with a control channel, wherein the control channel is quasi co-located with reference signal resources transmitted by the downlink serving beam (502).

12. The processing apparatus (100) according to any of the preceding claims, configured to:

performing the RA procedure in a Discontinuous Reception (DRX) connected state.

13. A client device (300) for a wireless communication system (500), the client device (300) comprising a processing device (100) according to any of the preceding claims.

14. A method for processing a device (100), the method (200) comprising:

(202) determining that a random access, RA, procedure needs to be performed when in a connected state with a network access node (400) using a downlink serving beam (502);

(204) obtaining RA parameters of the RA procedure, wherein the RA parameters indicate at least one RA resource and at least one RA preamble;

(206) selecting an uplink beam (512) of the RA procedure according to a quasi co-located association with reference signal resources received on a downlink beam from the network access node (400);

(208) transmitting the RA preamble in the RA resources to the network access node (400) over the selected uplink beam (512) to initiate the RA procedure;

15. A computer-readable medium comprising a computer program for performing the method of claim 14 when the computer program runs on a computer.