Methods of wireless communication device operation and methods of access node operation

Abstract

The present application relates to a method of operating a wireless communication device and a method of operating an access node. A method (400, 500) of operating a wireless communication device (101) and an access node (112) of a communication network (100) during a two-step random access procedure is provided. The method (400, 500) comprises the steps of transmitting (401, 501) a message from the access node (112) to the wireless communication device (101), the message comprising a configuration defining at least one of a plurality of different types of scheduling applicable for resource allocation of an uplink shared channel (211) of the communication network (100). An uplink message (2117) of the two-step random access procedure comprises a connection request for establishing a data connection between the wireless communication device (101) and the communication network (100), and the uplink message (2117) is transmitted (407, 507) on the uplink shared channel (211) in accordance with the configuration.

Description

TECHNICAL FIELD

[0001] Various examples relate to methods of operating a wireless communication device during a two-step random access procedure and of operating an access node of a communication network. BACKGROUND

[0002] In 3GPP standardization, a procedure for two-step random access in wireless communication networks has recently been proposed to further reduce latency and signaling with respect to the traditional four-step random access procedure.

[0003] In principle, the two-step random access procedure comprises all four messages of the four-step random access procedure, but the four messages are only communicated in two signaling steps. The first step (msgA) of the proposed procedure comprises the first and third steps of the known procedure (Msg1, Msg3), which respectively comprise a random access preamble (Msg1), followed by a connection request (Msg3). The second step (msgB) of the proposed procedure comprises the second and fourth steps of the known procedure (Msg2, Msg4), which respectively comprise a random access response (RAR) and a connection response. In other words, the proposed two-step random access procedure comprises an uplink step involving uplink messages, and a downlink step involving downlink messages. The content of msgA and msgB is discussed in 3GPP RAN2, and the channel structure carrying msgA and msgB is discussed in 3GPP RAN1.

[0004] The main issue related to the first step (MsgA) concerns the identification and allocation of the transmission occasion (i.e. time-frequency resources) of the uplink data (Msg3) by the user equipment (UE) in the uplink shared channel. Various different types of scheduling can be envisioned for the resource allocation, which can or can not be associated with the transmission occasion of the random access preamble.

[0005] Considering that wireless communication networks need to serve different use cases such as enhanced mobile broadband (eMBB), massive machine type communications (mMTC) and ultra-reliable and low latency communications (URLLC), and also need to reliably provide these services (i.e. by avoiding / minimizing collisions), the recently proposed two-step random access procedure needs to flexibly assign transmission occasions. SUMMARY

[0006] In a first aspect, a method of operating a wireless communication device is provided. The method comprises receiving a message from an access node of a communication network during a two-step random access procedure, the message comprising a configuration defining at least one of a plurality of different types of scheduling applicable for resource allocation of an uplink shared channel of the communication network; and transmitting an uplink message of the two-step random access procedure on the uplink shared channel in accordance with the configuration. The uplink message comprises a connection request for establishing a data connection between the wireless communication device and the communication network.

[0007] The method can further comprise selecting between a first type of scheduling and a second type of scheduling of the plurality of different types of scheduling in accordance with the configuration.

[0008] The method can further comprise transmitting an indication of a result of the selection to the access node.

[0009] The indication can be transmitted using a partitioning of a random access preamble of the random access procedure between the plurality of different types of scheduling.

[0010] The selection can depend on a modulation and / or coding scheme associated with the first type of scheduling and the second type of scheduling, respectively, in accordance with the configuration.

[0011] The selection can depend on a transport block size associated with the first type of scheduling and the second type of scheduling, respectively, in accordance with the configuration.

[0012] The selection can depend on a resource size associated with the first type of scheduling and the second type of scheduling, respectively, in accordance with the configuration.

[0013] The uplink message can further comprise uplink payload data, and the selection can depend on a comparison of a size of the uplink payload data and the resource size associated with the first type of scheduling and the second type of scheduling, respectively.

[0014] The selection can depend on a mode of operation of the wireless communication device for the communication network.

[0015] The selection can depend on a device category associated with the wireless communication device.

[0016] The method can further comprise the steps of receiving a selection command from the access node, the selection command indicating a selection between the first type of scheduling and the second type of scheduling of the plurality of different types of scheduling in accordance with the selection command; and disabling the first type of scheduling or the second type of scheduling of the plurality of different types of scheduling in accordance with the selection indicated by the selection command.

[0017] The selection command can be comprised in a paging message associated with the random access procedure.

[0018] The selection command can be comprised in a connection release message for releasing the data connection.

[0019] The configuration can be received in at least one of a broadcast system information block and a downlink control message addressed to the wireless communication device.

[0020] In a second aspect, there is provided a method of operating an access node of a communication network. The method comprises the steps of sending a message to a wireless communication device during a two-step random access procedure, the message comprising a configuration defining at least one of a plurality of different types of scheduling applicable for resource allocation of an uplink shared channel of the communication network; and receiving an uplink message of the two-step random access procedure on the uplink shared channel in accordance with the configuration. The uplink message comprises a connection request for establishing a data connection between the wireless communication device and the communication network.

[0021] The method can further comprise the steps of selecting between a first type of scheduling and a second type of scheduling of the plurality of different types of scheduling; and sending a selection command to the wireless communication device, the selection command indicating a selection between the first type of scheduling and the second type of scheduling of the plurality of different types of scheduling.

[0022] The selection can depend on an application associated with the data connection.

[0023] The first type of scheduling can define a timing for transmitting the uplink message on the uplink shared channel with reference to a timing of a random access preamble for transmitting the two-step random access procedure on a random access channel. The second type of scheduling can define a timing for transmitting the uplink message on the uplink shared channel with reference to a framing of a time-frequency resource grid defined by the communication network.

[0024] In a third aspect, a wireless communication device is provided. The device comprises a processing unit arranged to: receive, from an access node of a communication network, a message during a two-step random access procedure, the message comprising a configuration defining at least one of a plurality of different types of scheduling applicable for resource allocation of an uplink shared channel of the communication network; and transmit, on the uplink shared channel, an uplink message of the two-step random access procedure in accordance with the configuration. The uplink message comprises a connection request for establishing a data connection between the wireless communication device and the communication network.

[0025] The processing unit of the wireless communication device can be arranged to perform a method of operating the wireless communication device in accordance with various embodiments.

[0026] In a fourth aspect, an access node of a communication network is provided. The access node comprises a processing unit arranged to: transmit, to a wireless communication device, a message during a two-step random access procedure, the message comprising a configuration defining at least one of a plurality of different types of scheduling applicable for resource allocation of an uplink shared channel of the communication network; and receive, on the uplink shared channel, an uplink message of the two-step random access procedure in accordance with the configuration. The uplink message comprises a connection request for establishing a data connection between the wireless communication device and the communication network.

[0027] The processing unit of the access node can be arranged to perform a method of operating the access node of the communication network in accordance with various embodiments.

[0028] It will be appreciated that features described above and to be explained below can be used not only in the specified combinations but also in other combinations or alone, without departing from the scope of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 Communication between a UE and a BS on a wireless link is schematically illustrated in accordance with various examples.

[0030] Figure 2 A UE and a BS in accordance with various examples are schematically illustrated in more detail.

[0031] Figure 3 Aspects in relation to a cellular network in accordance with various examples are schematically illustrated.

[0032] Figure 4 Various network registration modes of a UE at a cellular network in accordance with various examples are schematically illustrated.

[0033] Figure 5A andFigure 5B A time-frequency resource grid of an uplink in a wireless link is schematically illustrated in accordance with various examples.

[0034] Figure 6 A flowchart of a method in accordance with various examples is illustrated. DETAILED DESCRIPTION

[0035] Some examples of the present disclosure generally provide a plurality of circuits or other electrical devices. All references to circuits and other electrical devices and functions provided by each are not intended to limit the scope of what is contained in this disclosure to only include what is explicitly described herein. Although specific labels are assigned to particular features described herein, such labels are not intended to limit the scope of the circuits and other electrical devices to what is described herein. Such circuits and other electrical devices can be combined with, and / or separated from, other circuits and other electrical devices in any manner based on desired types of electrical implementation. It is to be recognized that any of the circuits or other electrical devices disclosed herein can include any number of microcontrollers, graphics processor units (GPUs), integrated circuits, memory devices (e.g., flash memory, random access memory (RAM), read only memory (ROM), electrically programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), or other suitable variants thereof), and software that cooperate to execute the operations disclosed herein. Additionally, any one or more of the electrical devices can be configured to execute program code embodied in a non-transitory computer readable medium that is programmed to execute any number of the functions disclosed.

[0036] Embodiments of the present application will be described in detail below with reference to the attached drawings. It will be understood that the following description of embodiments is not intended to limit the application. The scope of the application is not intended to be limited by the embodiments described below or the attached drawings, which are to be considered as illustrative only.

[0037] The accompanying drawings will be considered in conjunction with the foregoing description, and it will be readily understood that the drawings are included to provide further assistance in understanding the application. The drawings are not intended to be exhaustive or to limit the application to the precise form disclosed. It will be readily understood that the function and general principles of the various elements of the drawings can be applied to any element thereof, and that the drawings, presented in a simplified form, are not intended to be understood as true in scale. Any connection or coupling between functional blocks, devices, components, or other physical or functional units shown in the drawings or described herein can also be implemented by indirect connections or couplings. The coupling between components can also be established by wireless connections. Functional blocks can be implemented in hardware, firmware, software, or a combination thereof.

[0038] Figure 1A wireless communication system 90 that can benefit from the technology disclosed herein is schematically illustrated. The communication system 90 comprises a user equipment (UE) 101 and an access node of a network, here implemented by a base station (BS) 112 of a cellular network. As a general rule, the technology described herein can be applied to various kinds and types of networks: the network can be a 3GPP standardized network, such as 3G, 4G-LTE or 5G-NR. Other examples include 3GPP narrow band Internet of Things (NB-IoT), enhanced Machine Type Communication (eMTC) or IEEE Wi-Fi networks.

[0039] A wireless link 114 is established between the BS 112 and the UE 101. The wireless link 114 comprises a downlink (DL) from the BS 112 to the UE 101; and also comprises an uplink (UL) from the UE 101 to the BS 112.

[0040] The wireless link 114 can be implemented on a dedicated spectrum. The dedicated spectrum can be fully controlled by the network operator.

[0041] The UE 101 can for example be one of the following: a smartphone; a cellular phone; a tablet; a notebook; a computer; a smart TV; an MTC device; an eMTC device; an IoT device; an NB-IoT device; a sensor; an actuator; etc.

[0042] The BS 112 comprises a processor (CPU) 1121 and an interface (IF) 1122 (sometimes also called front-end). The IF 1122 comprises a receiver and a transmitter. The BS 112 further comprises a memory (MEM) 1125 (for example, a non-volatile memory). The memory can store program code that can be executed by the processor 1121. The processor 1121 and the memory 1125 thus form a control circuit. Execution of the program code can cause the processor 1121 to perform steps of a method of operating an access node 112 of a communication network 100 according to various embodiments.

[0043] The UE 101 comprises a processor (CPU) 1011 and an interface (IF) 1012 (sometimes also called front-end). The IF 1012 comprises a receiver and a transmitter. The UE 101 further comprises a memory (MEM) 1015 (for example, a non-volatile memory). The memory 1015 can store program code that can be executed by the processor 1011. The processor 1011 and the memory 1015 thus form a control circuit. Execution of the program code can cause the processor 1011 to perform steps of a method of operating a wireless communication device 101 according to various embodiments.

[0044] Figure 3 An example implementation of the wireless communication network 100 is schematically illustrated in more detail. Figure 3An example illustrates a wireless network 100 according to the 3GPP 5G architecture. Details of the infrastructure are described in 3GPP TS 23.501, version 1.3.0 (2017-09). While Figure 3 and other parts described below illustrate techniques in the 3GPP 5G framework, similar techniques can be readily applied to different communication protocols. Examples include 3GPP LTE 4G and IEEE Wi-Fi technologies.

[0045] The UE 101 is able to connect to the wireless communication network 100 via a radio access network (RAN) 111, typically formed by one or more BSs 112. A wireless link 114 is established between the RAN 111, in particular one or more of the BSs 112 of the RAN 111, and the UE 101, enabling the communication system 90 (see Figure 1 ) to communicate.

[0046] The RAN 111 is connected to a core network (CN) 115. The CN 115 comprises a user plane (UP) 191 and a control plane (CP) 192. Application data is typically routed through the UP 191. To this end, UP functions (UPFs) 121 are provided. The UPFs 121 can implement router functions. Application data can pass through one or more UPFs 121. In Figure 3 the scenario of a UE 101 accessing a data network (DN) 180, such as the Internet or a local area network, the UPF 121 acts as a gateway to the DN 180. Application data can be communicated between the UE 101 and one or more servers on the DN 180.

[0047] The network 100 further comprises an access and mobility management function (AMF) 131; a session management function (SMF) 132; a policy control function (PCF) 133; an application function (AF) 134; a network slice selection function (NSSF) 134; an authentication server function (AUSF) 136; and a unified data management (UDM) 137. Figure 3 Protocol reference points N1-N22 between these nodes are also illustrated.

[0048] The AMF 131 provides one or more of the following functions: registration management; NAS termination; connection management; reachability management; mobility management; access authentication; and access authorization. The AMF 131 can track timing of a discontinuous reception (DRX) cycle of the UE 101. The AMF 131 can track various network registration modes in which the UE 101 can operate. The AMF 131 can trigger the BSs 112 of the RAN 111 to send a paging signal to the UE 101, e.g., in a tracking area or a registration area, to account for UE mobility.

[0049] If the respective UE 101 operates in connected mode, a data connection 189 is established by the AMF 131. To keep track of the current network registration mode of the UE 101, the AMF 131 sets the UE 101 to an evolved packet system connection management (ECM) connected or ECM idle. During ECM connected, a non-access stratum (NAS) connection is maintained between the UE 101 and the AMF 131. The NAS connection enables an example of a mobility control connection. The NAS connection can be established in response to a paging of the UE 101.

[0050] The SMF 132 provides one or more of the following functions: session management (including session establishment, modification and release, including bearer setup for UP bearers between the RAN 111 and the UPF 121); selection and control of UPF; configuration of traffic steering; roaming functionality; termination of at least some NAS messages, etc.

[0051] As such, both the AMF 131 and the SMF 132 implement CP mobility management required to support a mobile UE.

[0052] Figure 3 Aspects are also illustrated with respect to the data connection 189. The data connection 189 is established between the UE 101 and a DN 180 via the RAN 111 and the UPF 121 of the CN 115 and towards the DN 180. For example, a connection to the Internet or another packet data network can be established. To establish the data connection 189, the respective UE 101 can perform a random access (RA) procedure, e.g., in response to a reception of a paging signal. A server of the DN 180 can host a service that transmits application data (sometimes also referred to as payload data) via the data connection 189. The data connection 189 can comprise one or more bearers, such as a dedicated bearer or a default bearer. The data connection 189 can be defined on a radio resource control (RRC) layer (e.g., typically layer 3 of the OSI model).

[0053] Figure 4 Aspects are illustrated with respect to different network registration modes 301-304 in which the UE 101 can operate. For example, example implementations of the operating modes 301-304 are described in 3GPP TS 38.300 (e.g., version 15.0).

[0054] In connected mode 301, a control plane connection and a user plane connection are established between the UE 101 and the CN 115. This includes the setup of the data connection 189. For example, a default bearer and optionally one or more dedicated bearers can be setup between the UE 101 and the network 100. The receiver of the UE 101 can continuously operate in an active state. The connected mode 301 includes network-controlled UE mobility.

[0055] To reduce power consumption, the UE 101 can then be transitioned from the connected mode 301 to the connected mode 302 employing a DRX cycle of the receiver. The DRX cycle comprises an ON period and an OFF period according to a respective timing schedule. During the OFF period, the receiver is not adapted to receive data; an inactive state of the receiver can be activated.

[0056] The timing schedule of the DRX cycle is synchronized between the UE 101 and the BS 112, such that the network 100 can align any DL transmission (e.g., of application data) with the ON period of the connected mode DRX cycle. The ON period thus represents a period in which the UE 101 monitors the PDCCH for a potential indication of DL traffic by the network 100. In mode 302, the data connection 189 is maintained.

[0057] To achieve further power reduction, the UE 101 can be operated in idle mode 303.

[0058] The idle mode 303 is again associated with a DRX cycle of the receiver of the UE 101. However, during the on-duration of the DRX cycle in idle mode 303, the receiver is only adapted to receive paging indicators and optionally paging messages. This can help limit the specific bandwidth that needs to be monitored by the receiver during the on-duration of the DRX cycle in idle mode 303, for example. The receiver can not be adapted to receive application data. This can help further reduce power consumption (e.g., if compared to the connected mode 302). In idle mode 303, the UE also performs cell reselection when detecting that a given cell reselection criterion is met.

[0059] In inactive mode 304, the control plane and user plane connections between the UE 101 and the CN 115 are maintained (as in connected mode 301), and the UE 101 performs cell reselection (as in idle mode 303). In doing so, the UE 101 can move within a notification area configured by the RAN 111 without notifying the RAN 111, and paging is initiated by the RAN 111. This further reduces signaling and power consumption related thereto in view of new use cases such as enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra-reliable and low-latency communications (URLLC).

[0060] Figure 5A 、 Figure 5B Aspects with respect to a time-frequency resource grid 200A, 200B comprising a plurality of time-frequency resource elements in the uplink of the wireless link 114 are schematically illustrated. The time-frequency resource grid 200 is defined by the RAN 111 according to the respective RAT for communication on the wireless link 114 in the UL direction.

[0061] The time-frequency resource elements of the time-frequency resource grid 200A, 200B are defined by symbols and subcarriers according to OFDM modulation. Further, the time- frequency resource elements are structured in the time domain. To this end, a frame structure comprising transmission frames 201-203 is provided. The transmission frames 201-203 can be further subdivided into subframes and slots (not shown). For example, a frame can comprise a number (e.g., ten (10)) of subframes, and a given subframe can comprise one or more (e.g., one (1)) slots, and an individual slot can comprise fourteen (14) OFDM symbols.

[0062] As a general rule, the individual frames 201-203 of the frame structure have a certain sequence number (referred to as system frame number (SFN)). The sequence number of the frames 201-203 can implement a time reference of the respective cellular network 100. In addition, the subframes within a frame and / or the slots within a subframe can have a certain sequence number. Synchronization signals (not exemplified in Figure 5A Figure 5B ).

[0063] Figure 5A Figure 5B Aspects with respect to a plurality of channels 210-212 are also exemplified. In particular, different channels 210-212 can be associated with different time-frequency resource elements. Different channels 210-212 can be used for different types of signals. Different channels can use different modulation and coding schemes. For DL communication, there is a corresponding frame structure.

[0064] A first channel (e.g., implemented by a physical UL control channel (PUCCH) 210) in the shaded area in Figure 5A Figure 5B is an UL control channel. The PUCCH 210 may, for example, comprise a scheduling request (e.g., implemented by a buffer status report (BSR)). This can trigger scheduling by the BS 112. A scheduling grant on a physical DL control channel (PDCCH) (not shown in Figure 5A Figure 5B may be used to indicate a second channel (e.g., implemented by a physical UL shared channel (PUSCH) 211) in the shaded area in Figure 5A Figure 5B ​​​​​The fifth channel (not shown in FIG. 2B) can be implemented, for example, as a physical DL shared channel (PDSCH) 214. The PDSCH 214 can carry payload DL messages that bear higher layer data. For example, the higher layer messages can include application data or RRC control messages, such as a paging message. The paging message can indicate the identity of a particular UE that is to be paged.

[0065] The third channel (see thick solid line in FIG. 2A) can be implemented, for example, by a physical random access channel (PRACH) 212. The PRACH 212 can be used by the UE 101 and possibly other UEs 101 simultaneously to transmit a random access preamble, thereby initiating a random access procedure to establish a control plane connection and a data plane connection between the UE 101 and the CN 115. The network 100 can broadcast system information (i.e., SIB2) that defines those time-frequency resource elements of the time-frequency resource grid 200 that are assigned to the PRACH 212 and that can be used to transmit a random access preamble (so-called random access occasions (ROs) 212). Signaling can be reduced by predefining various preamble formats and resource assignments, which can be referenced and looked up using a PRACH configuration index. Figure 5A , Figure 5B The fourth channel (not shown in FIG. 2A) can be implemented, for example, as a physical DL control channel (PDCCH) 213. The PDCCH 213 can carry DL control signals. Examples include a paging indicator that enables the cellular network 100 (e.g., the AMF 131) to page the UE 101 during a paging occasion. The PDCCH 213 can also carry scheduling grants / assignments (sometimes referred to as DL control information (DCI)) on the fifth channel (not shown in FIG. 2A), which can be implemented, for example, by a physical DL shared channel (PDSCH) 214. The PDSCH 214 can be associated with payload DL messages that bear higher layer data. For example, the higher layer messages can include application data or RRC control messages, such as a paging message. The paging message can indicate the identity of a particular UE that is to be paged.

[0066] The sixth channel (see dashed line in FIG. 2A) can be implemented, for example, as a physical uplink control channel (PUCCH) 216. The PUCCH 216 can carry uplink control information (UCI) from the UE 101 to the network 100. Examples include a scheduling request (SR) and hybrid automatic repeat request (HARQ) feedback (e.g., an acknowledgement (ACK) or negative acknowledgement (NACK) for a DL message received by the UE 101). The PUCCH 216 can also carry a random access response (RAR) message from the network 100 to the UE 101. Figure 6 The reference signs 230-234 are further exemplified in connection with

[0067] The fifth channel (not shown in FIG. 2B) can be implemented, for example, as a physical DL shared channel (PDSCH) 214. The PDSCH 214 can carry payload DL messages that bear higher layer data. For example, the higher layer messages can include application data or RRC control messages, such as a paging message. The paging message can indicate the identity of a particular UE that is to be paged. Figure 5A , 5B The fourth channel (not shown in FIG. 2B) can be implemented, for example, as a physical DL control channel (PDCCH) 213. The PDCCH 213 can carry DL control signals. Examples include a paging indicator that enables the cellular network 100 (e.g., the AMF 131) to page the UE 101 during a paging occasion. The PDCCH 213 can also carry scheduling grants / assignments (sometimes referred to as DL control information (DCI)) on the fifth channel (not shown in FIG. 2B), which can be implemented, for example, by a physical DL shared channel (PDSCH) 214. The PDSCH 214 can be associated with payload DL messages that bear higher layer data. For example, the higher layer messages can include application data or RRC control messages, such as a paging message. The paging message can indicate the identity of a particular UE that is to be paged. Figure 5A , 5B The sixth channel (see dashed line in FIG. 2B) can be implemented, for example, as a physical uplink control channel (PUCCH) 216. The PUCCH 216 can carry uplink control information (UCI) from the UE 101 to the network 100. Examples include a scheduling request (SR) and hybrid automatic repeat request (HARQ) feedback (e.g., an acknowledgement (ACK) or negative acknowledgement (NACK) for a DL message received by the UE 101). The PUCCH 216 can also carry a random access response (RAR) message from the network 100 to the UE 101.

[0068] Figure 6Flowcharts of interrelated methods 400, 500 according to various examples are illustrated. The methods relate to the operation of a wireless communication device 101 and the operation of an access node 112 of a communication network 100, respectively. In particular, the wireless communication device 101 can be a user equipment (UE) and the access node 112 can be a base station (BS).

[0069] In Figure 6 In the middle, the basic steps of the above methods are represented with solid lines / borders and highlighted with shaded areas.

[0070] Configuration of multiple different types of scheduling

[0071] At block 501, the method 500 comprises the step of the access node / base station 112 transmitting 501, to the wireless communication device 101, a message during a two-step random access procedure, the message comprising a configuration defining at least one of a plurality of different types of scheduling that can be used for resource allocation of an uplink shared channel 211 of the communication network 100.

[0072] As used herein, one type of scheduling can relate to a configuration set by the network 100, in particular by the respective access node 112, and informing the wireless communication device 101 how to identify a transmission occasion of an uplink transmission during a two-step random access procedure in a physical uplink shared channel (PUSCH).

[0073] As used herein, a shared channel can relate to at least one recurring time-frequency resource element of a time-frequency resource grid 200, the temporary and mutually exclusive use of which by a plurality of UEs 101 is controlled by the respective access node 112 based on appropriate scheduling.

[0074] As used herein, a "random access procedure" is a signaling / handshake between a wireless communication device 101 and an access node 112 in a wireless communication network 100, which initializes the establishment of a control plane connection and a data plane connection between the wireless communication device 101 and the wireless communication network 100. In other words, the random access procedure precedes and prepares the transfer of payload data.

[0075] Correspondingly, at block 401, the method 400 comprises the step of the wireless communication device 101 receiving 401 a message from the access node 112 during the two-step random access procedure, the message comprising a configuration defining at least one of a plurality of different types of scheduling applicable for resource allocation of the uplink shared channel 211 of the communication network 100. The configuration can be received in at least one of a broadcast system information block 2141 (via PDSCH 214) and a downlink control message 2131 (via PDCCH 213) addressed to the wireless communication device 101, such as an RRC message. In particular, the configuration information can be split into parts transmitted 401, 501 via the broadcast system information block 2141 and the downlink control message 2131, respectively. For example, the availability of the plurality of different types of scheduling and a default configuration can be transmitted 401, 501 at least via the system broadcast message 2141. Further configuration details, such as pre-allocated PUSCH occasions or any time- and / or frequency-dependencies between PRACH occasions and PUSCH occasions (see below), can also be informed or updated via the UE-specific downlink control message 2131, i.e. an RRC message.

[0076] Irrespective of how the wireless communication device 101 is configured with the plurality of different types of scheduling, it is provided with a selection regarding the scheduling applicable for resource allocation of the uplink shared channel 211 of the communication network 100 during the two-step random access procedure. In other words, within the scope of the two-step random access procedure, the access node 112 can delegate the final selection among the plurality of types of uplink scheduling to the wireless communication device 101. However, there can be cases in which the access node 112 can want to force the wireless communication device 101 to use a particular scheduling among the plurality of different types of scheduling, either temporarily or permanently.

[0077] To this end, at block 502, the method 500 can further comprise the step of the access node 112 selecting 502 between a first type of scheduling and a second type of scheduling among the plurality of different types of scheduling. The selection 502 can depend on an application associated with the data connection. For example, the second type of scheduling can be selected for an NR unlicensed network due to the need for a listen-before-talk (LBT) technique, i.e. a technique in which a radio transmitter used in radio communication first senses its radio environment before it starts transmission.

[0078] At block 503, the method 500 can further comprise the step of the access node 112 sending 503 a selection command to the wireless communication device 101, the selection command indicating to select 503 between the first type of scheduling and the second type of scheduling among the plurality of different types of scheduling.

[0079] Correspondingly, at block 403, the method 400 can further comprise the step of the wireless communication device 101 receiving 403 a selection command from the access node 112, the selection command indicating to select 502 between a first type of scheduling and a second type of scheduling of the plurality of different types of scheduling in accordance with the selection command.

[0080] At block 404, the method 400 can further comprise the step of the wireless communication device 101 disabling 404 the first type of scheduling or the second type of scheduling of the plurality of different types of scheduling in accordance with the selection indicated by the selection command. If the wireless communication device 101 is in idle mode 303 (mobile terminated case), the selection command can be comprised in a paging message 2143A (via PDSCH 214) associated with a random access procedure. Alternatively, if the wireless communication device 101 is in connected mode 301 or connected mode with receiver’s DRX cycle 302, the selection command can be comprised in a connection release message 2143B (via PDSCH 214) for releasing a data connection. As used herein, the terms “disable” and “enable” can refer to “not enable” and “not disable”, respectively.

[0081] In other words, the access node 112 can reduce the number of available options for the wireless communication device 101 to select 405 one of the plurality of different types of scheduling available for resource allocation, which is next described. It is noted that the network 100 can configure a specific scheduling of the plurality of different types of scheduling available for resource allocation by disabling all options but one of the selection step 405.

[0082] Selection from multiple different types of scheduling

[0083] At block 405, the method 400 can further comprise the step of the wireless communication device 101 selecting 405 between the first type of scheduling and the second type of scheduling of the plurality of different types of scheduling in accordance with the configuration. The first type of scheduling can define a PUSCH occasion 220 (see Figure 5A ) for transmitting 407 an uplink message 2117 on an uplink shared channel (PUSCH) 211 with reference to a PRACH occasion (see Figure 5A ) for transmitting 406 a random access preamble 2126 of a two-step random access procedure on a random access channel (PRACH) 212. Figure 5A Possible definitions of the respective PUSCH occasion 220 of a preceding PRACH occasion 212 are exemplified with reference 230, 232. The PUSCH occasion 220 can be defined with reference 232 to the start of the preceding PRACH occasion 212, or with reference 230 to the end of the preceding PRACH occasion 212 (see Figure 5A). Alternative examples with an implicit periodicity according to the PRACH occasions 212 can be envisaged, wherein the POs 220 can be provided in any subframe of any frame, but always referring to the PRACH occasions 212. In contrast, the second type scheduling reference 234 defines the PUSCH occasions 220 for transmitting 407 an uplink message 2117 on an uplink shared channel (PUSCH) 211 (see Figure 5B ) from a framing of the time-frequency resource grid 200 defined by the communication network 100, i.e. without any direct reference to any PRACH occasion (see reference sign 212 in Figure 5B ) for transmitting 406 a random access preamble 2126 on the random access channel 212. Figure 5B Possible definitions of the PUSCH occasions 220 referring to the beginning of a system frame are exemplified. In a particular example, the PUSCH occasions (POs) 220 are provided in subframes 3 and 8 of each frame 201-203. Alternative examples with an implicit periodicity can be envisaged, wherein the POs 220 can be provided in any subframe / slot of any frame. Further examples with an implicit offset with respect to the beginning of the system frames 201-203 can be envisaged, wherein the POs 220 can be provided with an offset of N subframes / slots with respect to the beginning of the system frames 201-203.

[0084] At block 405, the selection 405A can additionally or alternatively depend on a modulation and / or coding scheme (MCS) associated with the first type scheduling and the second type scheduling, respectively, according to a configuration. For example, the first type scheduling can be associated with BPSK / QPSK and the second type scheduling can be associated with higher order modulation such as 16QAM and above.

[0085] As used herein, a “modulation and / or coding scheme” can relate to a particular selection of modulation order and code rate for physical layer encoding.

[0086] At block 405, the selection 405B can additionally or alternatively depend on a transport block size (TBS) associated with the first type scheduling and the second type scheduling, respectively, according to a configuration. For example, the first type scheduling can be associated with a TBS up to 100 bits and the second type scheduling can be associated with a larger TBS such as up to 1000 bits. Thus, if the UE has needed to transmit small data during connection establishment, it can use the second type scheduling.

[0087] As used herein, a “transport block size” can relate to the number of bits (including a medium access control (MAC) header and a payload) that can be transmitted per subframe, i.e. per millisecond.

[0088] At block 405, depending on the configuration, the selection 405C can additionally or alternatively depend on resource sizes associated with the first type of scheduling and the second type of scheduling, respectively. The uplink message 2117 can also comprise uplink payload data, and the selection 405C can depend on a comparison of a size of the uplink payload data with resource sizes associated with the first type of scheduling and the second type of scheduling, respectively.

[0089] As used herein, a "resource size" can relate to an extension of a time- frequency resource grid 200 in frequency and time. In frequency, a resource size can be expressed as a number of subcarriers. In time, a resource size can be expressed as a number of subframes and / or slots. For example, since the smallest resource unit that can be allocated to a user in an LTE network is a resource block (RB) of size 12 subcarriers and 1 slot, a resource size can also be expressed as a number of resource blocks (RBs) in such a network.

[0090] At block 405, depending on the configuration, the selection 405 can additionally or alternatively depend on coverage enhancement (CE) modes associated with the first type of scheduling and the second type of scheduling, respectively. For example, the first type of scheduling can be associated with a particular CE mode, and the second type of scheduling can be associated with another CE mode (or none at all).

[0091] As used herein, a "coverage enhancement mode" relates to a transmission mode that implies multiple transmission repetitions, such that individual data packets are repeated tens, hundreds or even thousands of times to improve the chance of successful transmission. In particular, different CE modes imply different numbers of transmission repetitions.

[0092] At block 405, the selection 405D can additionally or alternatively depend on a mode of operation 301-304 of the wireless communication device 101 with respect to the communication network 100 (see Figure 3 ).

[0093] For example, in the idle mode 303, the first type of scheduling can be used by default, while the second type of scheduling can be used for specific use cases, such as unlicensed operation, or early / small data transmission, as indicated via system information.

[0094] For example, upon entering the inactive mode 304, the use of the first type of scheduling or the second type of scheduling can be configured by the network 110, e.g., by including a selection command in a connection release message 2143B used to release the data connection.

[0095] For example, in the connected mode 301, the configuration of the plurality of different types of scheduling can be dynamically changed to temporarily enable / disable a particular scheduling of the plurality of different types of scheduling. In particular, the first type of scheduling can be used when a radio link failure occurs (however, a fallback to a four-step random access procedure can be envisaged for a wide range of radio link failures), and the second type of scheduling can be used, among others, after a handover procedure from a source access node 112 to a target access node 112, wherein the source access node 112 can prepare the UE 101 for the configuration of the plurality of different types of scheduling suitable for the target access node 112.

[0096] At block 405, the selection 405E can additionally or alternatively depend on a device category associated with the wireless communication device 101. For example, mMTC UEs that can require transmission repetitions can select the first type of scheduling (assuming that this scheduling type supports appropriate CE modes).

[0097] Msg 1 (RA preamble)

[0098] At block 406, the wireless communication device 101 transmits a random access preamble 2126 to the access node 112, thereby initiating the two-step random access procedure. To this end, the wireless communication device 101 selects an appropriate random access preamble out of a set of random access preambles given by the network 100, selects an appropriate available periodic PRACH occasion out of one or more available periodic PRACH occasions provided / configured by the network 100 for transmitting 406 the random access preamble 2126 of the two-step random access procedure on a random access channel (PRACH) 212, and transmits the selected preamble 2126 at the selected PRACH occasion. In NR networks, this message is known as Msgl.

[0099] At block 406, the method 400 can further comprise the step of transmitting 406 an indication of the result of the selection 405, 405A-405E to the access node 112. The indication can be transmitted 406 using a partitioning of random access preambles of the random access procedure between the plurality of different types of scheduling. A similar partitioning is known in NR networks, wherein a fixed number (64) of preamble signatures is available in each NR cell, and wherein these signatures are partitioned between signatures for contention-based access and signatures allocated to specific UEs on a contention-free basis. Incidentally, in the partitioning used herein, a random access preamble can be used to distinguish between the plurality of different types of scheduling. For example, preamble indices 0-32 and 33-63 can represent the first type of scheduling and the second type of scheduling of the plurality of different types of scheduling, respectively (or vice versa).

[0100] ​Correspondingly, at block 506, the access node 112 receives a random access preamble 2126 from the wireless communication device 101 at the selected PRACH occasion.

[0101] In a conventional four-step random access procedure, upon successful detection of a random access preamble at a PRACH occasion, the receiving access node 112 will schedule UL resources, i.e. a PUSCH occasion 220, and optionally provide timing advance (TA) information. In LTE networks, this information will be transmitted to the wireless communication device 101 in a DL message called Msg2. In response, the wireless communication device(s) 101 that have transmitted the same random access preamble 2126 will transmit a RRC connection request, their unique identity (UE ID) and a buffer status report (BSR) at the PUSCH occasion 220. In LTE networks, this message is called Msg3.

[0102] Msg 3 (RRC connection request)

[0103] In contrast to the conventional approach described above, at block 407, the method 400 comprises the step of transmitting 407, by the wireless communication device 101, an uplink message 2117 (corresponding to Msg3 in LTE) of the two-step random access procedure in an uplink shared channel (PUSCH) 211 according to the configuration previously received 401 from the network 100.

[0104] More specifically, according to the methods 400, 500, the time and / or frequency offset of the PUSCH occasion 220 for the uplink message 2117 is defined according to the scheduling of the plurality of different types of scheduling selected 405 by the wireless communication device 101 and enabled (i.e. not disabled 404) by the access node 112. In other words, the PUSCH occasion 220 to be used for Msg3 can be defined with reference to (i.e. relative to) the PRACH occasion, or independently / solo.

[0105] For example, according to a first type of scheduling of the plurality of different types of scheduling, the time and / or frequency offset of the PUSCH occasion 220 for the uplink message 2117 relative to the selected PRACH occasion can depend on (i.e. be a function of) the index of the selected random access preamble 2126. For example, the preamble index N can be associated with a PUSCH resource unit (PRU) N of the PUSCH occasion. In other words, the respective PUSCH occasion can be sliced into PRUs according to the preamble index. The configuration of the first type of scheduling of the plurality of different types of scheduling can comprise this dependency of the time and / or frequency offset of the PUSCH occasion 220, e.g. as a lookup table (LUT). The time and / or frequency offset of the PUSCH occasion 220 can be defined relative to the start time or the end time of the selected PRACH occasion.

[0106] The first type of scheduling described above reduces connection control signaling by pre-configuring PUSCH occasions relative to PRACH occasions, thereby pre-defining the PUSCH occasion to be used for the uplink message 2117 based on the selected PRACH occasion.

[0107] For example, according to a second type of scheduling out of the plurality of different types of scheduling, the PUSCH occasion 220 to be used for the uplink message 2117 can be independent of any PRACH occasion. The network 100 can individually establish recurring PUSCH occasions 220, which can be defined based on and relative to a given framing (described in the above and in Figure 5B For example, the PUSCH occasions can be provided in every M-th system frame, optionally shifted / offset by N system frames, where M and N are reconfigurable integer values. Within a system frame, there can be multiple PUSCH occasions. As such, the individually established PUSCH occasions and PRACH occasions can or can not coincide. The configuration of the second type of scheduling out of the plurality of different types of scheduling can comprise information about the established recurring PUSCH occasions 220, e.g., as a list, as a LUT, or as a formula / equation to generate the next available PUSCH occasion for the current SFN.

[0108] The second type of scheduling described above reduces connection control signaling by pre-configuring PUSCH occasions relative to system framing, thereby pre-defining the next available PUSCH occasion to be used for the uplink message 2117 based on the current system frame number (SFN), subframe number, and time slot number.

[0109] It can be beneficial to use a particular scheduling out of the plurality of different types of scheduling as a default mode for most UEs and to use another scheduling out of the plurality of different types of scheduling as an alternative based on payload attributes or device attributes / states. One possible scenario can be to use the first type of scheduling out of the plurality of different types of scheduling as a default, e.g., to schedule PUSCH occasions for legacy Msg3 messages. For example, the second type of scheduling out of the plurality of different types of scheduling can be used whenever a larger transport block size (TBS) is required, or if transmission repetition is required.

[0110] The configuration of the plurality of different types of scheduling enables the respective access node 112 to define the plurality of different types of scheduling and to dynamically enable / disable / switch between the plurality of different types of scheduling according to use cases and varying circumstances at the access node 112.

[0111] The configuration of the plurality of different types of scheduling also enables the wireless communication device 101 to use each of the enabled plurality of different types of scheduling individually or simultaneously and to dynamically switch between the enabled plurality of different types of scheduling according to use cases and varying circumstances at the device 101.

[0112] As in the Msg3 of the legacy LTE or NR, the uplink message 2117 includes the RRC connection request, the unique identity (UE ID) and the buffer status report (BSR) of the wireless communication device 101. In addition, the uplink message 2117 can also include the uplink payload data (such as small data).

[0113] Correspondingly, at block 507, the method 500 includes the step of accessing node 112 receiving 507 the uplink message 2117 of the two-step random access procedure on the uplink shared channel (PUSCH) 211 according to the configuration.

[0114] In the two-step random access procedure defined for the NR network, the first step MsgA includes the combination of Msg1 and Msg3.

[0115] Msg 2 (RA response)

[0116] At block 508, upon successfully detecting the random access preamble 2126 at the PRACH occasion at block 506, the receiving access node 112 schedules the UL resource, i.e. the PUSCH occasion 220, and transmits 508 a DL message 2138 via the PDCCH 213, which includes the corresponding random access response (RAR) of the wireless communication device 101 and optional timing advance (TA) information. In the LTE network, this message is referred to as Msg2.

[0117] Correspondingly, at block 408, the wireless communication device 101 receives 408 the DL message 2138.

[0118] Msg 4 (RRC response / connection setup complete)

[0119] At block 509, the access node 112 selects the identity (UE ID) of one of the one or more wireless communication devices 101 that have transmitted the same random access preamble 2126 and transmits 509 an RRC response / connection setup complete message 2149 including the selected identity to the wireless communication device 101 via the PDSCH 214 for the contention resolution. In the LTE network, this message is referred to as Msg4.

[0120] Correspondingly, at block 409, the wireless communication device 101 receives 409 the RRC response / connection setup complete message 2149 including the selected identity. Only when the selected identity corresponds to the unique identity (UE ID) of the wireless communication device 101, the identified wireless communication device 101 confirms the reception of the contention resolution (not illustrated in the figure). Figure 6

[0121] ​In the two-step random access procedure defined for NR networks, the second step, MsgB, includes a combination of Msg2 and Msg4.

[0122] While the application has been shown and described with reference to certain preferred embodiments, other equivalents and modifications will occur to others skilled in the art upon reading and understanding the foregoing description. The application includes all such equivalents and modifications and is limited only by the scope of the claims.

[0123] To illustrate, various examples have been described with respect to wireless communication devices and access nodes / base stations (BSs) of a cellular network that communicate over a licensed spectrum. The BSs act as schedulers for the UEs. As a general rule, similar techniques can be applied to other devices (e.g., wireless communication devices and access nodes of a non-cellular network).

[0124] To further illustrate, various examples have been described with respect to a two-step random access procedure that involves four messages, which are transmitted in the order of Msgl > Msg3 > Msg2 > Msg4 in Figure 6 However, those skilled in the art will appreciate that, for example, the two-step random access procedure can also involve transmitting Msgl and Msg3 simultaneously, and / or transmitting Msg2 and Msg4 simultaneously.

Claims

1. A method (400) for operating a wireless communication device (101), the method (400) comprising the following steps: - Prior to the two-step random access procedure, a message (401) is received from the access node (112) of the communication network (100). This message includes a configuration defining at least one of several different types of scheduling that can be used for resource allocation on the uplink shared channel (211) of the communication network (100) during the two-step random access procedure. The different types of scheduling differ in how they define the timing of uplink message transmission. This configuration informs the wireless communication device (101) how to identify the timing of uplink transmission on the uplink shared channel (211) during the two-step random access procedure. - According to the configuration, the uplink message (2117) of the two-step random access procedure is sent (407) on the uplink shared channel (211), the uplink message (2117) including a connection request for establishing a data connection between the wireless communication device (101) and the communication network (100).

2. The method (400) according to claim 1, further comprising the following step: - Based on the configuration, select between the first type of scheduling and the second type of scheduling among the multiple different types of scheduling.

3. The method (400) according to claim 2, further comprising the following step: - Send an indication (406) of the result of the selection to the access node (112).

4. The method (400) according to claim 3, in, The instruction is sent among the plurality of different types of scheduling using the partitioning of the random access preamble of the random access procedure.

5. The method (400) according to any one of claims 2 to 4, in, According to the configuration, the selection depends on the modulation and / or coding schemes associated with the first type of scheduling and the second type of scheduling, respectively.

6. The method (400) according to any one of claims 2 to 4, in, According to the configuration, the selection depends on the transport block size associated with the first type of scheduling and the second type of scheduling, respectively.

7. The method (400) according to any one of claims 2 to 4, in, According to the configuration, the selection depends on the resource size associated with the first type of scheduling and the second type of scheduling, respectively.

8. The method (400) according to claim 7, in, The uplink message (2117) also includes uplink payload data. The selection depends on a comparison between the size of the uplink payload data and the size of the resources associated with the first type of scheduling and the second type of scheduling, respectively.

9. The method (400) according to any one of claims 2 to 4, in, The selection depends on the operating mode of the wireless communication device (101) for the communication network (100).

10. The method (400) according to any one of claims 2 to 4, in, The selection depends on the device category associated with the wireless communication device (101).

11. The method (400) according to any one of claims 2 to 4, wherein the method (400) further comprises the following step: - Receive (403) a selection command from the access node (112), the selection command instructing (502) to select between a first type of schedule and a second type of schedule among a plurality of different types of schedules, and - Based on the selection indicated by the selection command, disable (404) the first type of scheduling or the second type of scheduling among the plurality of different types of scheduling.

12. The method (400) according to claim 11, in, The selection command is included in the paging message (2143A) associated with the random access procedure.

13. The method (400) according to claim 11, in, The selection command is included in the connection release message (2143B) used to release the data connection.

14. The method (400) according to claim 1, in, The configuration is received in at least one of a broadcast system information block (2141) and a downlink control message (2131) addressed to the wireless communication device (101).

15. The method (400) according to any one of claims 2 to 4, in, The first type of scheduling reference defines the timing for sending (406) the random access preamble (2126) of the two-step random access procedure on the random access channel (212) to define the timing for sending (407) the uplink message (2117) on the uplink shared channel (211), and The second type of scheduling refers to the framing of the time-frequency resource grid (200) defined by the communication network (100) to define the timing for sending (407) the uplink message (2117) on the uplink shared channel (211).

16. A method (500) for operating an access node (112) of a communication network (100), the method (500) comprising the following steps: - Prior to the two-step random access procedure, a message (501) is sent to the wireless communication device (101), the message including a configuration defining at least one of several different types of scheduling for resource allocation on the uplink shared channel (211) of the communication network (100) during the two-step random access procedure, wherein the different types of scheduling differ in how the timing of uplink message transmission is defined, the configuration informing the wireless communication device (101) how to identify the timing of transmission for uplink transmission on the uplink shared channel (211) during the two-step random access procedure, and -According to the configuration, the uplink message (2117) of the two-step random access procedure is received (507) on the uplink shared channel (211), the uplink message (2117) including a connection request for establishing a data connection between the wireless communication device (101) and the communication network (100).

17. The method (500) according to claim 16, further comprising the step of: - Select between the first type of scheduling and the second type of scheduling among the multiple different types of scheduling (502), - Send a (503) selection command to the wireless communication device (101), the selection command indicating the selection between the first type of scheduling and the second type of scheduling among the plurality of different types of scheduling.

18. The method (500) according to claim 17, in, The choice depends on the application associated with the data connection.

19. The method (500) according to claim 17 or 18, in, The first type of scheduling reference defines the timing for sending (406) the random access preamble (2126) of the two-step random access procedure on the random access channel (212) to define the timing for sending (407) the uplink message (2117) on the uplink shared channel (211), and The second type of scheduling refers to the framing of the time-frequency resource grid (200) defined by the communication network (100) to define the timing for sending (407) the uplink message (2117) on the uplink shared channel (211).

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