WO2025217835A1

WO2025217835A1 - Resource allocation for message

Info

Publication number: WO2025217835A1
Application number: PCT/CN2024/088359
Authority: WO
Inventors: Pingping Wen; Srinivasan Selvaganapathy; Mads LAURIDSEN; Ping Yuan
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy; Nokia Technologies Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy; Nokia Technologies Oy
Priority date: 2024-04-17
Filing date: 2024-04-17
Publication date: 2025-10-23
Anticipated expiration: 2026-10-17

Abstract

Example embodiments of the present disclosure provide a solution for resource allocation for a message in a random access procedure. In an example method, a terminal device receives a configuration comprising information related to downlink (DL) assignment for a second message. The second message comprises contention resolution. The terminal device transmits a first message comprising a random access preamble. The terminal device monitors the second message based on the configuration. In this way, the DL signaling can be reduced efficiently by pre-configuring DL resources for Msg4 transmission or MsgB transmission, thereby reducing the impact on UL capacity due to limitations in the corresponding DL signaling capacity and unlocking additional UL capacity potential, and thus the UL capacity can be enhanced.

Description

RESOURCE ALLOCATION FOR MESSAGE

FIELD

Various example embodiments relate to the field of communication, and in particular, to devices, methods, apparatuses, and a computer readable medium for resource allocation for a message, such as, a random access message 4 (Msg4) or a random access message B (MsgB) .

BACKGROUND

A communication network can be seen as a facility that enables communications between two or more communication devices, or provides communication devices access to a data network. A mobile or wireless communication network is one example of a communication network.

Such communication networks operate in accordance with standards, such as those promulgated by 3GPP (Third Generation Partnership Project) or ETSI (European Telecommunications Standards Institute) . Examples of such standards include the so-called 5G (5th Generation) standard or other standards promulgated by 3GPP.

SUMMARY

In general, example embodiments of the present disclosure provide a solution for resource allocation for a message a random access procedure, especially for resource allocation for Msg4 or MsgB in Internet of things (IoT) over a non-terrestrial network (NTN) .

In a first aspect, there is provided a terminal device. The terminal device comprises at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the terminal device at least to: receive a configuration comprising information related to downlink (DL) assignment for a second message, wherein the second message comprises contention resolution; transmit a first message comprising a random access preamble; and monitor the second message based on the configuration.

In a second aspect, there is provided a network device. The network device comprises at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the network device at least to: transmit a configuration comprising information related to downlink (DL) assignment for a second message, wherein the second message comprises contention resolution; receive a first message comprising a random access preamble; and transmit the second message based on the configuration.

In a third aspect, there is provided a method. The method comprises: receiving a configuration comprising information related to downlink (DL) assignment for a second message, wherein the second message comprises contention resolution; transmitting a first message comprising a random access preamble; and monitoring the second message based on the configuration.

In a fourth aspect, there is provided a method. The method comprises: transmitting a configuration comprising information related to downlink (DL) assignment for a second message, wherein the second message comprises contention resolution; receiving a first message comprising a random access preamble; and transmitting the second message based on the configuration.

In a fifth aspect, there is provided an apparatus. The apparatus comprises: means for receiving a configuration comprising information related to downlink (DL) assignment for a second message, wherein the second message comprises contention resolution; means for transmitting a first message comprising a random access preamble; and means for monitoring the second message based on the configuration.

In a sixth aspect, there is provided an apparatus. The apparatus comprises: means for transmitting a configuration comprising information related to downlink (DL) assignment for a second message, wherein the second message comprises contention resolution; means for receiving a first message comprising a random access preamble; and means for transmitting the second message based on the configuration.

In a seventh aspect, there is provided a non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least method of the above third aspect or fourth aspect.

In an eighth aspect, there is provided a computer program comprising instructions, which, when executed by an apparatus, cause the apparatus to perform at least the method of the above third aspect or fourth aspect.

In a ninth aspect, there is provided a terminal device. The terminal device comprises: receiving circuitry configured to receive a configuration comprising information related to downlink (DL) assignment for a second message, wherein the second message comprises contention resolution; transmitting circuitry configured to transmit a first message comprising a random access preamble; and monitoring circuitry configured to monitor the second message based on the configuration.

In a tenth aspect, there is provided a network device. The network device comprises: first transmitting circuitry configured to transmit a configuration comprising information related to downlink (DL) assignment for a second message, wherein the second message comprises contention resolution; receiving circuitry configured to receive a first message comprising a random access preamble; and second transmitting circuitry configured to transmit the second message based on the configuration.

It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Some example embodiments will now be described with reference to the accompanying drawings, in which:

FIG. 1A illustrates an example communication environment in which embodiments of the present disclosure may be implemented;

FIG. 1B illustrates an example four step random access procedure;

FIG. 1C illustrates an example two step random access procedure;

FIG. 2 illustrates an example of a process flow in accordance with some example embodiments of the present disclosure;

FIG. 3 illustrates an example solution of pre-configured DL assignment for Msg4 in four step random access procedure in accordance with some example embodiments of the present disclosure;

FIG. 4 illustrates an example solution of pre-configured DL assignment for MsgB in two step random access procedure in accordance with some example embodiments of the present disclosure;

FIG. 5 illustrates a flowchart of an example method implemented at a terminal device in accordance with some other embodiments of the present disclosure;

FIG. 6 illustrates a flowchart of an example method implemented at a network device in accordance with some other embodiments of the present disclosure;

FIG. 7 illustrates a simplified block diagram of a device that is suitable for implementing some example embodiments of the present disclosure; and

FIG. 8 illustrates a block diagram of an example of a computer-readable medium in accordance with some example embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numerals represent the same or similar elements.

DETAILED DESCRIPTION

Principles of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

References in the present disclosure to “one embodiment, ” “an embodiment, ” “an example embodiment, ” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It shall be understood that although the terms “first” and “second” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” , “comprising” , “has” , “having” , “includes” and/or “including” , when used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof. As used herein, “at least one of the following: <a list of two or more elements>” and “at least one of <a list of two or more elements>” and similar wording, where the list of two or more elements are joined by “and” or “or” , mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

As used in this application, the term “circuitry” may refer to one or more or all of the following:

(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

(b) combinations of hardware circuits and software, such as (as applicable) :

(i) a combination of analog and/or digital hardware circuit (s) with software/firmware and

(ii) any portions of hardware processor (s) with software (including digital signal processor (s) ) , software, and memory (ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

(c) hardware circuit (s) and or processor (s) , such as a microprocessor (s) or a portion of a microprocessor (s) , that requires software (for example, firmware) for operation, but the software may not be present when it is not needed for operation.

This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

As used herein, the term “network” , “communication network” or “data network” refers to a network following any suitable communication standards, such as long term evolution (LTE) , LTE-advanced (LTE-A) , wideband code division multiple access (WCDMA) , high-speed packet access (HSPA) , narrow band Internet of things (NB-IoT) , wireless fidelity (Wi-Fi) , non-terrestrial network (NTN) and so on. Furthermore, the communications between a terminal device and a network device/element in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the fourth generation (4G) , 4.5G, the fifth generation (5G) , the future sixth generation (6G) , IEEE 802.11 communication protocols, and/or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

As used herein, the term “network device” refers to a node in a communication network via which a terminal device receives services (e.g., positioning services) therefrom. The network device may refer to a core network device or access network device, such as base station (BS) or an access point (AP) or a transmission and reception point (TRP) , for example, a node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , a NR NB (also referred to as a gNB) , a remote radio unit (RRU) , a radio header (RH) , a remote radio head (RRH) , a WiFi device, a relay, a low power node such as a femto, a pico, and so forth, depending on the applied terminology and technology. In the following description, the terms “network device” , “AP device” , “AP” and “access point” may be used interchangeably.

The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE) , a Subscriber Station (SS) , a Portable Subscriber Station, a Mobile Station (MS) , a station (STA) or station device, or an Access Terminal (AT) . The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA) , portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE) , laptop-mounted equipment (LME) , USB dongles, smart devices, wireless customer-premises equipment (CPE) , an Internet of Things (IoT) device, a watch or other wearable, a head-mounted display (HMD) , a vehicle, a drone, a medical device and applications (for example, remote surgery) , an industrial device and applications (for example, a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts) , a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. In the following description, the terms “station” , “station device” , “STA” , “terminal device” , “communication device” , “terminal” , “user equipment” and “UE” may be used interchangeably.

Principles and embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Reference is first made to FIG. 1A, which illustrates an example communication environment 100 in which embodiments of the present disclosure may be implemented. FIG. 1A illustrates two types of communication networks, including a non-terrestrial network (NTN) and a terrestrial network (TN) . In the NTN network, a terminal device 110-1 and a network device 120-1 can communicate with each other. The network device 120-1 in the NTN network may be, for example, an eNB that provides communication coverage through space-borne vehicles (such as satellites) . In the TN network, a terminal device 110-2 and a network device 120-2 can communicate with each other. The network device 120-2 in the TN network may be, for example, a gNB that provides communication coverage.

In communication systems, “UL” refers to a communication link in a direction from a terminal device to a network device, and “DL” refers to a communication link in a direction from the network device to the terminal device.

It is to be understood that FIG. 1A is illustrated only for the purpose of illustration without suggesting any limitations. For example, the environment 100 may include any suitable number of network devices and terminal devices adapted for implementing embodiments of the present disclosure.

Communications in the communication environment 100 may be implemented according to any proper communication protocol (s) , comprising, but not limited to, cellular communication protocols of the first generation (1G) , the second generation (2G) , the third generation (3G) , the fourth generation (4G) , the fifth generation (5G) , and the sixth generation (6G) and on the like, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and/or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA) , Frequency Division Multiple Access (FDMA) , Time Division Multiple Access (TDMA) , Frequency Division Duplex (FDD) , Time Division Duplex (TDD) , Multiple-Input Multiple-Output (MIMO) , Orthogonal Frequency Division Multiple (OFDM) , Discrete Fourier Transform spread OFDM (DFT-s-OFDM) and/or any other technologies currently known or to be developed in the future.

Non-terrestrial communication can be in a complementary manner to terrestrial deployments where satellite connectivity can provide coverage beyond terrestrial deployments. Current narrow band Internet of things (NB-IoT) NTN UL system capacity is limited by the corresponding system DL capacity due to larger signaling overhead in DL (up to ～53%) , and tight coupling between UL and DL signaling. Every time a UE needs to transmit UL data, it requires an approximately equal number of DL control messages from the network. This impacts predominantly UL driven traffic, such as Mobile Originated (MO) transmissions. There is a need to propose methods to reduce the DL signaling.

FIG. 1B illustrates an example contention based four step random access procedure. As illustrated in FIG. 1B, the contention based four step random access procedure includes the following steps.

In step 1, a UE 110 transmits a random access preamble (i.e., Msg1 131) on random access channel (RACH) in UL. For example, the UE randomly selects a random access preamble, and transmits the preamble on the resources based on physical random access channel (PRACH) configuration provided by the network.

In step 2, the UE 110 receives a random access response (RAR) (i.e., Msg2 132) generated by MAC on DL-SCH from the eNB 120. For example, after the preamble transmission, the UE monitors the physical downlink control channel (PDCCH) during the RAR window. The RAR message conveys at least random access (RA) -preamble identifier, timing alignment information, initial UL grant, and assignment of Temporary cell radio network temporary identifier (C-RNTI) .

In step 3, the UE 110 transmits radio resource control (RRC) connection request (i.e., Msg3 133) to the eNB 120. For example, after the reception and processing of the Msg2, the UE 110 sends the Msg3 to request RRC connection from the network.

In step 4, the UE 110 receives contention resolution on DL (i.e., Msg4 134-2) . For example, MSG4 is sent by the network (e.g., via physical downlink shared channel (PDSCH) ) to resolve for the contention based random access procedure. Msg4 includes the identity of the UE 110 which Msg3 is correctly decoded. Prior to receiving Msg4, the terminal should monitor the PDCCH (134-1) with the Temporary C-RNTI which is allocated by the network in Msg2. If the UE detects its own UE identity sent to the network in Msg3, random access is considered successful. The Temporary C-RNTI is promoted to C-RNTI for the UE.

Downlink control information (DCI) format N1 is used for the scheduling of one NPDSCH codeword per transmission time interval (TTI) in one cell, e.g. for msg4. The DCI corresponding to a narrow band physical downlink control channel (NPDCCH) order is carried by NPDCCH. The following information in Table 1 is transmitted by means of the DCI format N1.

Table 1. DCI format N1 for NPDSCH scheduling in NB-IoT

It should be noted that the four step random access procedure can also be used with Early Data Transmission (EDT) . Specifically, for Mobile Originated traffic, the UE can provide uplink data in Msg3, while for Mobile Terminated traffic, the eNB can provide downlink data in Msg4.

FIG. 1C illustrates an example contention based two-step random access procedure. Generally, as compared with the above mentioned four step random access procedure, in step 1 of the two step random access procedure, MsgA 141 is a combination of Msg1 and Msg3. Moreover, in step 2 of the two step random access procedure, MsgB 142 is a combination of Msg2 and Msg4.

According to the four step random access procedure, each time a UE sends a preamble (i.e., Msg1) , it is accompanied by the following signals: Msg2, Msg3, and Msg4 (when Msg1 and Msg3 are decoded correctly) , which always requires the PDCCH signaling to allocate PDSCH resources to Msg4. Hence, there is a need to reduce the DL PDCCH signaling for Msg4 transmissions.

Therefore, some embodiments of the present disclosure propose a solution for resource allocation for Msg4 in four step random access procedure or MsgB in two step random access procedure. In this solution, a terminal device receives a configuration comprising information related to downlink (DL) assignment for a second message. The second message comprises contention resolution. Also, the terminal device transmits a first message comprising a random access preamble. In addition, the terminal device monitors the second message based on the configuration. By implementing the example embodiments of the present disclosure, the DL PDCCH control signaling for Msg4 and MsgB scheduling can be avoided. The DL signaling can be reduced efficiently by pre-configuring DL resources for Msg4 transmission or MsgB transmission, thereby reducing the impact on UL capacity due to limitations in the corresponding DL signaling capacity and unlocking additional UL capacity potential, thus the UL capacity can be enhanced.

For illustrative purposes, principles and example embodiments of the present disclosure will be described below with reference to FIG. 1 to FIG. 8. However, it is to be noted that these embodiments are given to enable the skilled in the art to understand inventive concepts of the present disclosure and implement the solution as proposed herein, and not intended to limit scope of the present application in any way.

FIG. 2 illustrates an example of a process flow 200 in accordance with some example embodiments of the present disclosure. For ease of understanding, the process flow 200 will be described with reference to FIG. 1. It would be appreciated that although the process flow 200 has been described referring to the communication environment 100 of FIG. 1, this process flow 200 may be likewise applied to other similar communication scenarios.

As shown in FIG. 2, at 230, a network device 220 may transmit a configuration 232 comprising information related to downlink (DL) assignment for a second message 254. For example, the second message comprises contention resolution. Accordingly, at 234, the terminal device 210 may receive the configuration 232. Thereafter, at 240, the terminal device 210 may transmit a first message 242 comprising a random access preamble. Accordingly, at 244, the network device 220 may receive the first message 242.

At 250, the terminal device 210 may monitor the second message 254 based on the configuration 232. At 252, the network device 220 may transmit the second message 254 based on the configuration 232.

In some embodiments, the first message is the random access preamble in four step random access procedure, and the second message is a random access message 4 (Msg4) in four step random access procedure, the network device may further transmit a random access response (RAR) , which may be received by the terminal device. Accordingly, the terminal device may transmit a random access message 3 (Msg3) , which may be received by the network device.

In some embodiments, the configuration is received via a system information block (SIB) , and the information at least comprises a predetermined relationship between information for a random access message other than the Msg4 and the DL assignment for the Msg4. In some embodiments, the predetermined relationship comprises a mapping rule or a mapping table between the information for the random access message other than the Msg4 and the DL assignment for the Msg4.

In some embodiments, the predetermined relationship comprises: a first relationship between information related to a random access preamble transmission in a random access message 1 (Msg1) and the DL assignment for the Msg4, a second relationship between resource assignment for RAR and the DL assignment for the Msg4, a third relationship between UL grant for the Msg3 and the DL assignment for the Msg4, or any combination thereof.

In some embodiments, the first relationship comprises a mapping relationship between the information related to the random access preamble transmission in the Msg1 and the DL assignment for the Msg4, and the information related to the random access preamble comprise: information related to physical random access channel (PRACH) preamble, or information related to physical random access channel (PRACH) resource, or both. In some embodiments, the predetermined relationship comprises an offset to be applied to: a time domain resource, a frequency domain resource, a modulation and coding scheme (MCS) index, or any combination thereof.

Additionally or alternatively, in some embodiments, the configuration is received via a system information block (SIB) , and the SIB comprises at least one parameter of the DL assignment for the Msg4. In some embodiments, the at least one parameter comprises: a scheduling delay, a resource assignment, a modulation and coding scheme (MCS) , a repetition number, a hybrid automatic repeat request (HARQ) -acknowledgement (ACK) resource, or any combination thereof. In some embodiments, the at least one parameter comprises at least part of fields in: a DCI format for physical downlink shared channel (PDSCH) scheduling, or a DCI format N1 for narrow-band physical downlink shared channel (NPDSCH) scheduling, or both. In some embodiments, the SIB comprises SIB1, and the at least one parameter of the DL assignment for the Msg4 comprises at least one DownlinkConfigCommon information element (IE) in SIB1.

In some embodiments, the DL assignment for the Msg4 is deactivated or activated by the network device. In some embodiments, the monitoring of the Msg4 based on the configuration is based on determining that a reference signal received power (RSRP) of the terminal device is above a threshold configured by the network device. In some embodiments, when there is Msg3 decoding failure at the network device, the terminal device may further receive collision information related to collision of receiving Msg3 at the network device.

In some embodiments, when there is Msg3 decoding failure at the network device, the collision information is received in the Msg4, and the collision information comprises an indication that there is Msg3 decoding failure at the network device due to incorrect decoding of Msg3. Alternatively, in some embodiments, when there is Msg3 decoding failure at the network device, the Msg4 comprise at least two transport block sizes (TBSs) , the network device may further transmit the collision information in a second TBS of the two TBSs based on determining that there is Msg3 decoding failure at the network device due to incorrect decoding of Msg3, and the terminal device may further determine that the second TBS of the two TBSs comprises the collision information based on determining that an attempt to decode for actual Msg4 with valid contents in a first TBS of the two TBSs is failed.

Alternatively, in some embodiments, when there is Msg3 decoding failure at the network device, the configuration is a first configuration, the terminal device may further receive a second configuration for a message to be transmitted on an additional resource block prior to receiving the first configuration, and the message to be transmitted on the additional resource block comprises a bitmap of RAR preambles for which valid Msg4 is available. In some embodiments, the first message is a MsgA in two step random access procedure, and the second message is a MsgB in two step random access procedure.

In some embodiments, the configuration is received via a system information block (SIB) , and the information at least comprises a predetermined fourth relationship between information for the MsgA and the DL assignment for the MsgB. In some embodiments, the fourth relationship comprises a mapping relationship between the information related to the MsgA and the DL assignment for the MsgB, and the information related to the MsgA comprises: information related to physical random access channel (PRACH) preamble, information related to physical random access channel (PRACH) resource, information related to physical uplink shared channel (PUSCH) transmission, or any combination thereof.

In some embodiments, the fourth relationship comprises an offset to be applied to: a time domain resource, a frequency domain resource, a modulation and coding scheme (MCS) index, or any combination thereof. In some embodiments, the configuration is received via a system information block (SIB) , and the SIB comprises at least one parameter of the DL assignment for the MsgB.

In some embodiments, when transmitting the second message based on the configuration, the network device may transmit the second message on a physical downlink shared channel (PDSCH) based on the configuration, and the network device may refrain from transmitting a downlink control information (DCI) on a physical downlink control channel (PDCCH) that schedules the PDSCH for the second message.

Accordingly, in some embodiments, when monitoring the second message based on the configuration, the terminal device may monitor the second message on the PDSCH based on the configuration, and the terminal device may refrain from monitoring the DCI on the PDCCH that schedules the PDSCH for the second message.

FIG. 3 illustrates an example solution of pre-configured DL assignment 305 for Msg4 340 in four step random access procedure in accordance with some example embodiments of the present disclosure.

As illustrated in FIG. 3, the solution includes the following aspects. The DL assignment 305 for Msg4 340 is pre-defined/preconfigured, e.g. the DL assignment is informed from the network (e.g., eNB 120) to UE 110 via system information block (SIB) . As such, the PDCCH signaling for Msg4 transmissions can be reduced.

In some aspects, for example, the fields/parameters of the DL assignment can be included in the SIB1, e.g., in the information element (IE) of DownlinkConfigCommon. All fields or part of the fields in DCI format N1 (as in Table1) can be included in the DL assignment. One example is the DL assignment will be with the following information: scheduling delay (e.g., 3 bits) , resource assignment (e.g., 3 bits) , modulation and coding scheme (MCS) (e.g., 4 bits) , repetition number (e.g., 4 bits) , HARQ-ACK resource (e.g., 4 bits) , or any combination thereof.

In some other aspects, for example, the mapping rule or mapping table between the information for Msg1 310/Msg2 320/Msg3 330 and DL assignment 305 for Msg4 340 can be pre-defined or informed from the network to the UE. For this case, the network not only configures the DL resources for Msg4 transmission but also configures the mapping rule or mapping table between the information of Msg1/Msg2/Msg3 and DL assignment for Msg4 to the UE. Both the network and the UE know the mapping relationship.

As such, the UE can deduce the DL assignment for Msg4 through one of the following relationships. A first relationship may be the relationship between the PRACH preamble/PRACH resources and Msg4. For example, there is a mapping relationship between the information for Msg1 (e.g. the preamble or the PRACH frequency-time resources) and the DL assignment for Msg4. For another example, one preamble corresponds to one set of DL assignment. When the UE transmits the preamble, it will know the DL assignment for Msg4.

A second relationship may be the relationship between the random-access response and Msg4. For example, there is a mapping relationship between the resources assignment for RAR (i.e., Msg2) and the DL assignment for Msg4. When the UE receive DL assignment for Msg2, it knows the corresponding DL assignment for Msg4. A third relationship may be the relationship between the UL grant for Msg3 and Msg4. For example, there is a mapping relationship between the UL grant for Msg3 and the DL assignment for Msg4. When the UE receive the UL grant for Msg3 from RAR MAC PDU, it knows the corresponding DL assignment for Msg4. Moreover, the resource relationship defines an offset in: a time domain resource, a frequency domain resource, a modulation and coding scheme (MCS) index, or any combination thereof.

In some scenarios, the pre-configured DL resources for Msg4 transmission can be deactivated and/or activated by the network. For example, a set of DL assignments is informed to the UE by the network via SIB, and the network can activate a specific DL assignment of the set and inform the DL assignment index to the UE via RAR, e.g., the “R” bits in RAR. If pre-configured DL assignment is not activated or the DL assignment index is not informed, or the DL assignment index is given as index 0 to the UE by the network, the UE will perform the normal random access procedure to monitor and receive PDCCH for Msg4.

In some implementations, the above scheme of pre-configured resource assignment for Msg4 can be applied for the users which RSRP is above a threshold. The threshold can be informed from the network to the UE together with the DL assignment configuration via SIB. Since the channel received by the UE with large RSRP may be of good quality and the Msg1/Msg3 can be decoded correctly with high probability, thus Msg4 transmission for this UE is with high probability.

Furthermore, if there is a collision with Msg3, i.e., multiple terminals select the same preamble, the network may not be able to decode any Msg3, and Msg4 will not be sent. In this case, the network can inform the collision information to the UE. As a first option, the Msg4 sent in the pre-configured resources can indicate Msg3 decoding failure when no Msg3 is decoded correctly. For example, the Msg4 sent in the pre-configured resources can indicate Msg3 decoding failure with a short message. For this case, the UE will retransmit Msg3 based on the network instruction. As a second option, two TBS sizes are provided for Msg4, where the UE may first attempt to decode for actual Msg4 with valid contents. If the attempt fails, the UE will decode for Msg4 with single bit ‘Msg3-collision’ .

As a third option, in addition to the pre-configured resources for Msg4, an additional resource block is pre-configured before the resources for Msg4, which is used for a new message that contains bitmap of RAR preambles for which valid Msg4 is available. As such, the UE first decodes this message and then decode Msg4, the message can indicate whether Msg3 reception is success or not (i.e., whether valid Msg4 is available or not) . If valid Msg4 is scheduled, then it will be decoded. Otherwise, it will declare failure on reading this part.

FIG. 4 illustrates an example solution of pre-configured DL assignment 405 for MsgB 420 in two step random access procedure in accordance with some example embodiments of the present disclosure. As illustrated in FIG. 4, the solution includes the following aspects. The DL assignment 405 for MsgB 420 is pre-defined/preconfigured, e.g. the DL assignment is informed from the network (e.g., eNB 120) to UE 110 via system information block (SIB) .

In some other aspects, for example, the mapping rule or mapping table between the information for MsgA 410 and DL assignment 405 for MsgB 420 can be pre-defined or informed from the network to the UE. For this case, the network not only configures the DL resources for MsgB transmission but also configures the mapping rule or mapping table between the information of MsgA and DL assignment for MsgB to the UE. Both the network and the UE know the mapping relationship.

As such, the UE can deduce the DL assignment for MsgB through a fourth relationship, that is, the relationship between the PRACH preamble/PRACH resources and MsgB. For example, there is a mapping relationship between the information for MsgA (e.g. the preamble or the PRACH frequency-time resources) and the DL assignment for MsgB. For another example, one preamble corresponds to one set of DL assignment. When the UE transmits the preamble, it will know the DL assignment for MsgB. Moreover, the resource relationship defines an offset in: a time domain resource, a frequency domain resource, a modulation and coding scheme (MCS) index, or any combination thereof.

In some scenarios, the pre-configured DL resources for MsgB transmission can be deactivated and/or activated by the network. If pre-configured DL assignment is not activated, the UE will perform the normal random access procedure to monitor and receive PDCCH for MsgB.

In some implementations, the above scheme of pre-configured resource assignment for MsgB can be applied for the users which RSRP is above a threshold. The threshold can be informed from the network to the UE together with the DL assignment configuration via SIB. Since the channel received by the UE with large RSRP may be of good quality and the MsgA can be decoded correctly with high probability, thus MsgB transmission for this UE is with high probability.

FIG. 5 illustrates a flowchart of an example method 500 implemented at a terminal device in accordance with some other embodiments of the present disclosure. For ease of understanding, the method 500 will be described from the perspective of the terminal device 210 with reference to FIG. 2.

At block 510, the terminal device may receive a configuration comprising information related to downlink (DL) assignment for a second message, wherein the second message comprises contention resolution. At block 520, the terminal device may transmit a first message comprising a random access preamble. At block 530, the terminal device may monitor the second message based on the configuration.

In some embodiments, the first message is the random access preamble in four step random access procedure, and the second message is a random access message 4 (Msg4) in four step random access procedure, the terminal device may further receive a random access response (RAR) , and transmit a random access message 3 (Msg3) .

In some embodiments, the configuration is received via a system information block (SIB) , and the information at least comprises a predetermined relationship between information for a random access message other than the Msg4 and the DL assignment for the Msg4.

In some embodiments, the predetermined relationship comprises a mapping rule or a mapping table between the information for the random access message other than the Msg4 and the DL assignment for the Msg4.

In some embodiments, the first relationship comprises a mapping relationship between the information related to the random access preamble transmission in the Msg1 and the DL assignment for the Msg4, and the information related to the random access preamble comprise: information related to physical random access channel (PRACH) preamble, or information related to physical random access channel (PRACH) resource, or both.

In some embodiments, the predetermined relationship comprises an offset to be applied to: a time domain resource, a frequency domain resource, a modulation and coding scheme (MCS) index, or any combination thereof.

In some embodiments, the DL assignment for the Msg4 is deactivated or activated by a network device.

In some embodiments, the monitoring of the Msg4 based on the configuration is based on determining that a reference signal received power (RSRP) of the terminal device is above a threshold configured by a network device.

In some embodiments, the terminal device may further receive collision information related to collision of receiving Msg3 at a network device.

In some embodiments, the collision information is received in the Msg4, and the collision information comprises an indication that there is Msg3 decoding failure at the network device due to incorrect decoding of Msg3.

Alternatively, in some embodiments, the Msg4 comprise at least two transport block sizes (TBSs) , and the terminal device may further determine that a second TBS of the two TBSs comprises the collision information based on determining that an attempt to decode for actual Msg4 with valid contents in a first TBS of the two TBSs is failed.

Alternatively, in some embodiments, the configuration is a first configuration, and the terminal device may further receive a second configuration for a message to be transmitted on an additional resource block prior to receiving the first configuration, wherein the message to be transmitted on the additional resource block comprises a bitmap of RAR preambles for which valid Msg4 is available.

In some embodiments, the first message is a MsgA in two step random access procedure, and the second message is a MsgB in two step random access procedure.

In some embodiments, the configuration is received via a system information block (SIB) , and the information at least comprises a predetermined fourth relationship between information for the MsgA and the DL assignment for the MsgB.

In some embodiments, the fourth relationship comprises a mapping relationship between the information related to the MsgA and the DL assignment for the MsgB, and the information related to the MsgA comprises: information related to physical random access channel (PRACH) preamble, information related to physical random access channel (PRACH) resource, information related to physical uplink shared channel (PUSCH) transmission, or any combination thereof.

In some embodiments, the fourth relationship comprises an offset to be applied to: a time domain resource, a frequency domain resource, a modulation and coding scheme (MCS) index, or any combination thereof.

In some embodiments, the configuration is received via a system information block (SIB) , and the SIB comprises at least one parameter of the DL assignment for the MsgB.

In some embodiments, when monitoring the second message based on the configuration, the terminal device may monitor the second message on a physical downlink shared channel (PDSCH) based on the configuration, and the terminal device may refrain from monitoring a downlink control information (DCI) on a physical downlink control channel (PDCCH) that schedules the PDSCH for the second message.

FIG. 6 illustrates a flowchart of an example method 600 implemented at a network device in accordance with some other embodiments of the present disclosure. For ease of understanding, the method 600 will be described from the perspective of the network device 220 with reference to FIG. 2.

At block 610, the network device may transmit a configuration comprising information related to downlink (DL) assignment for a second message, wherein the second message comprises contention resolution. At block 620, the network device may receive a first message comprising a random access preamble. At block 630, the network device may transmit the second message based on the configuration.

In some embodiments, the first message is the random access preamble in four step random access procedure, and the second message is a random access message 4 (Msg4) in four step random access procedure, the network device may further transmit a random access response (RAR) , and receive a random access message 3 (Msg3) .

In some embodiments, the configuration is transmitted via a system information block (SIB) , and the information at least comprises a predetermined relationship between information for a random access message other than the Msg4 and the DL assignment for the Msg4.

Additionally or alternatively, in some embodiments, the configuration is transmitted via a system information block (SIB) , and the SIB comprises at least one parameter of the DL assignment for the Msg4. In some embodiments, the at least one parameter comprises: a scheduling delay, a resource assignment, a modulation and coding scheme (MCS) , a repetition number, a hybrid automatic repeat request (HARQ) -acknowledgement (ACK) resource, or any combination thereof. In some embodiments, the at least one parameter comprises at least part of fields in: a DCI format for physical downlink shared channel (PDSCH) scheduling, or a DCI format N1 for narrow-band physical downlink shared channel (NPDSCH) scheduling, or both. In some embodiments, the SIB comprises SIB1, and the at least one parameter of the DL assignment for the Msg4 comprises at least one DownlinkConfigCommon information element (IE) in SIB1.

In some embodiments, the configuration is applied at a terminal device based on determining that a reference signal received power (RSRP) of the terminal device is above a threshold configured by the network device.

In some embodiments, the network device may further transmit collision information related to collision of receiving Msg3 at a network device.

Alternatively, in some embodiments, the Msg4 comprise at least two transport block sizes (TBSs) , and the network device may further transmit the collision information in a second TBS of the two TBSs based on determining that there is Msg3 decoding failure at the network device due to incorrect decoding of Msg3.

Alternatively, in some embodiments, the configuration is a first configuration, and the network device may further transmit a second configuration for a message to be transmitted on an additional resource block prior to transmitting the first configuration, wherein the message to be transmitted on the additional resource block comprises a bitmap of RAR preambles for which valid Msg4 is available.

In some embodiments, the configuration is transmitted via a system information block (SIB) , and the information at least comprises a predetermined fourth relationship between information for the MsgA and the DL assignment for the MsgB.

In some embodiments, the configuration is transmitted via a system information block (SIB) , and the SIB comprises at least one parameter of the DL assignment for the MsgB.

In some embodiments, an apparatus capable of performing any of the method 500 (for example, the terminal device 210) may comprise means for performing the respective steps of the method 500. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some embodiments, the apparatus comprises means for receiving a configuration comprising information related to downlink (DL) assignment for a second message, wherein the second message comprises contention resolution; means for transmitting a first message comprising a random access preamble; and means for monitoring the second message based on the configuration.

In some embodiments, the first message is the random access preamble in four step random access procedure, and the second message is a random access message 4 (Msg4) in four step random access procedure, the apparatus further comprises means for receiving a random access response (RAR) , and means for transmitting a random access message 3 (Msg3) .

Alternatively, in some embodiments, the Msg4 comprise at least two transport block sizes (TBSs) , and the apparatus further comprises means for determining that a second TBS of the two TBSs comprises the collision information based on determining that an attempt to decode for actual Msg4 with valid contents in a first TBS of the two TBSs is failed.

Alternatively, in some embodiments, the configuration is a first configuration, and the apparatus further comprise means for receiving a second configuration for a message to be transmitted on an additional resource block prior to receiving the first configuration, wherein the message to be transmitted on the additional resource block comprises a bitmap of RAR preambles for which valid Msg4 is available.

In some embodiments, the means for monitoring the second message based on the configuration comprises means for monitoring the second message on a physical downlink shared channel (PDSCH) based on the configuration, and the apparatus further comprises means for refraining from monitoring the DCI on a physical downlink control channel (PDCCH) that schedules the PDSCH for the second message.

In some embodiments, the apparatus further comprises means for performing other steps in some embodiments of the method 500. In some embodiments, the means comprises at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

In some embodiments, an apparatus capable of performing any of the method 600 (for example, the network device 220) may comprise means for performing the respective steps of the method 600. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some embodiments, the apparatus comprises means for transmitting a configuration comprising information related to downlink (DL) assignment for a second message, wherein the second message comprises contention resolution; means for receiving a first message comprising a random access preamble; and means for transmitting the second message based on the configuration.

In some embodiments, the first message is the random access preamble in four step random access procedure, and the second message is a random access message 4 (Msg4) in four step random access procedure, the apparatus further comprises means for transmitting a random access response (RAR) , and means for receiving a random access message 3 (Msg3) .

In some embodiments, the apparatus further comprises means for transmitting collision information related to collision of receiving Msg3 at a network device.

Alternatively, in some embodiments, the Msg4 comprise at least two transport block sizes (TBSs) , and the apparatus further comprises means for transmitting the collision information in a second TBS of the two TBSs based on determining that there is Msg3 decoding failure at the network device due to incorrect decoding of Msg3.

Alternatively, in some embodiments, the configuration is a first configuration, and the apparatus further comprises means for transmit a second configuration for a message to be transmitted on an additional resource block prior to transmitting the first configuration, wherein the message to be transmitted on the additional resource block comprises a bitmap of RAR preambles for which valid Msg4 is available.

In some embodiments, the means for transmitting the second message based on the configuration comprises means for transmitting the second message on a physical downlink shared channel (PDSCH) based on the configuration, and the apparatus further comprises means for refraining from transmitting a downlink control information (DCI) on a physical downlink control channel (PDCCH) that schedules the PDSCH for the second message.

In some embodiments, the apparatus further comprises means for performing other steps in some embodiments of the method 600. In some embodiments, the means comprises at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

FIG. 7 illustrates a simplified block diagram of a device 700 that is suitable for implementing some example embodiments of the present disclosure. The device 700 may be provided to implement a communication device, for example, the terminal device 210 or the network device 220 as shown in FIG. 2. As shown, the device 700 includes one or more processors 710, one or more memories 720 coupled to the processor 710, and one or more communication modules 740 coupled to the processor 710.

The communication module 740 is for bidirectional communications. The communication module 740 has at least one antenna to facilitate communication. The communication interface may represent any interface that is necessary for communication with other network elements.

The processor 710 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 700 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

The memory 720 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 724, an electrically programmable read only memory (EPROM) , a flash memory, a hard disk, a compact disc (CD) , a digital video disk (DVD) , and other magnetic storage and/or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 722 and other volatile memories that will not last in the power-down duration.

A computer program 730 includes computer executable instructions that are executed by the associated processor 710. The program 730 may be stored in the ROM 724. The processor 710 may perform any suitable actions and processing by loading the program 730 into the RAM 722.

The embodiments of the present disclosure may be implemented by means of the program 730 so that the device 700 may perform any process of the disclosure as discussed with reference to FIGS. 5 and 6. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

In some example embodiments, the program 730 may be tangibly contained in a computer-readable medium which may be included in the device 700 (such as in the memory 720) or other storage devices that are accessible by the device 700. The device 700 may load the program 730 from the computer-readable medium to the RAM 722 for execution. The computer-readable medium may include any types of tangible non-volatile storage, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like.

FIG. 8 illustrates a block diagram of an example of a computer-readable medium 1000 in accordance with some example embodiments of the present disclosure. The computer-readable medium 800 has the program 830 stored thereon. It is noted that although the computer-readable medium 800 is depicted in form of CD or DVD in FIG. 8, the computer-readable medium 800 may be in any other form suitable for carry or hold the program 830.

Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the method 500 or 600 as described above with reference to FIG. 5 or 6. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

In the context of the present disclosure, the computer program codes or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer-readable medium, and the like.

The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. A computer-readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer-readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. The term “non-transitory, ” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM) .

Further, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

Although the present disclosure has been described in languages specific to structural features and/or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

A terminal device comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the terminal device at least to:

receive a configuration comprising information related to downlink (DL) assignment for a second message, wherein the second message comprises contention resolution;

transmit a first message comprising a random access preamble; and

monitor the second message based on the configuration.
The terminal device of claim 1, wherein the first message is the random access preamble in four step random access procedure, and the second message is a random access message 4 (Msg4) in four step random access procedure, and wherein the terminal device is further caused to:

receive a random access response (RAR) ; and

transmit a random access message 3 (Msg3) .
The terminal device of claim 2, wherein the configuration is received via a system information block (SIB) , and the information at least comprises a predetermined relationship between information for a random access message other than the Msg4 and the DL assignment for the Msg4.
The terminal device of claim 3, wherein the predetermined relationship comprises a mapping rule or a mapping table between the information for the random access message other than the Msg4 and the DL assignment for the Msg4.
The terminal device of claim 3, wherein the predetermined relationship comprises at least one of the following:

a first relationship between information related to a random access preamble transmission in a random access message 1 (Msg1) and the DL assignment for the Msg4;

a second relationship between resource assignment for RAR and the DL assignment for the Msg4; or

a third relationship between UL grant for the Msg3 and the DL assignment for the Msg4.
The terminal device of claim 5, wherein the first relationship comprises a mapping relationship between the information related to the random access preamble transmission in the Msg1 and the DL assignment for the Msg4, and the information related to the random access preamble comprise at least one of the following:

information related to physical random access channel (PRACH) preamble; or

information related to physical random access channel (PRACH) resource.
The terminal device of claim 3, wherein the predetermined relationship comprises an offset to be applied to at least one of the following:

a time domain resource;

a frequency domain resource; or

a modulation and coding scheme (MCS) index.
The terminal device of claim 2, wherein the configuration is received via a system information block (SIB) , and the SIB comprises at least one parameter of the DL assignment for the Msg4.
The terminal device of claim 8, wherein the at least one parameter comprises at least one of the following:

a scheduling delay;

a resource assignment;

a modulation and coding scheme (MCS) ;

a repetition number; or

a hybrid automatic repeat request (HARQ) -acknowledgement (ACK) resource.
The terminal device of claim 8, wherein the at least one parameter comprises at least part of fields in at least one of the following:

a DCI format for physical downlink shared channel (PDSCH) scheduling; or

a DCI format N1 for narrow-band physical downlink shared channel (NPDSCH) scheduling.
The terminal device of claim 8, wherein the SIB comprises SIB1, and the at least one parameter of the DL assignment for the Msg4 comprises at least one DownlinkConfigCommon information element (IE) in SIB1.
The terminal device of claim 2, wherein the DL assignment for the Msg4 is deactivated or activated by a network device.
The terminal device of claim 2, wherein the monitoring of the Msg4 based on the configuration is based on determining that a reference signal received power (RSRP) of the terminal device is above a threshold configured by a network device.
The terminal device of any of claims 1-13, wherein the terminal device is further caused to:

receive collision information related to collision of receiving Msg3 at a network device.
The terminal device of claim 14, wherein the collision information is received in the Msg4, and the collision information comprises an indication that there is Msg3 decoding failure at the network device due to incorrect decoding of Msg3.
The terminal device of claim 14, wherein the Msg4 comprise at least two transport block sizes (TBSs) , and the terminal device is further caused to:

determine that a second TBS of the two TBSs comprises the collision information based on determining that an attempt to decode for actual Msg4 with valid contents in a first TBS of the two TBSs is failed.
The terminal device of claim 14, wherein the configuration is a first configuration, and the terminal device is further caused to:

receive a second configuration for a message to be transmitted on an additional resource block prior to receiving the first configuration, wherein the message to be transmitted on the additional resource block comprises a bitmap of RAR preambles for which valid Msg4 is available.
The terminal device of claim 1, wherein the first message is a MsgA in two step random access procedure, and the second message is a MsgB in two step random access procedure.
The terminal device of claim 18, wherein the configuration is received via a system information block (SIB) , and the information at least comprises a predetermined fourth relationship between information for the MsgA and the DL assignment for the MsgB.
The terminal device of claim 19, wherein the fourth relationship comprises a mapping relationship between the information related to the MsgA and the DL assignment for the MsgB, and the information related to the MsgA comprises at least one of the following:

information related to physical random access channel (PRACH) preamble; or

information related to physical random access channel (PRACH) resource.

information related to physical uplink shared channel (PUSCH) transmission.
The terminal device of claim 19, wherein the fourth relationship comprises an offset to be applied to at least one of the following:

a time domain resource;

a frequency domain resource; or

a modulation and coding scheme (MCS) index.
The terminal device of claim 18, wherein the configuration is received via a system information block (SIB) , and the SIB comprises at least one parameter of the DL assignment for the MsgB.
The terminal device of claim 1, monitoring the second message based on the configuration comprises:

monitoring the second message on a physical downlink shared channel (PDSCH) based on the configuration, and the terminal device is further caused to:

refrain from monitoring a downlink control information (DCI) on a physical downlink control channel (PDCCH) that schedules the PDSCH for the second message.
A network device comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the network device at least to:

transmit a configuration comprising information related to downlink (DL) assignment for a second message, wherein the second message comprises contention resolution;

receive a first message comprising a random access preamble; and

transmit the second message based on the configuration.
The network device of claim 24, wherein the first message is the random access preamble in four step random access procedure, and the second message is a random access message 4 (Msg4) in four step random access procedure, and wherein the network device is further caused to:

transmit a random access response (RAR) ; and

receive a random access message 3 (Msg3) .
The network device of claim 25, wherein the configuration is transmitted via a system information block (SIB) , and the information at least comprises a predetermined relationship between information for a random access message other than the Msg4 and the DL assignment for the Msg4.
The network device of claim 26, wherein the predetermined relationship comprises a mapping rule or a mapping table between the information for the random access message other than the Msg4 and the DL assignment for the Msg4.
The network device of claim 26, wherein the predetermined relationship comprises at least one of the following:

a first relationship between information related to a random access preamble transmission in a random access message 1 (Msg1) and the DL assignment for the Msg4;

a second relationship between resource assignment for RAR and the DL assignment for the Msg4; or

a third relationship between UL grant for the Msg3 and the DL assignment for the Msg4.
The network device of claim 28, wherein the first relationship comprises a mapping relationship between the information related to the random access preamble transmission in the Msg1 and the DL assignment for the Msg4, and the information related to the random access preamble comprise at least one of the following:

information related to physical random access channel (PRACH) preamble; or

information related to physical random access channel (PRACH) resource.
The network device of claim 26, wherein the predetermined relationship comprises an offset to be applied to at least one of the following:

a time domain resource;

a frequency domain resource; or

a modulation and coding scheme (MCS) index.
The network device of claim 25, wherein the configuration is transmitted via a system information block (SIB) , and the SIB comprises at least one parameter of the DL assignment for the Msg4.
The network device of claim 31, wherein the at least one parameter comprises at least one of the following:

a scheduling delay;

a resource assignment;

a modulation and coding scheme (MCS) ;

a repetition number; or

a hybrid automatic repeat request (HARQ) -acknowledgement (ACK) resource.
The network device of claim 31, wherein the at least one parameter comprises at least part of fields in at least one of the following:

a DCI format for physical downlink shared channel (PDSCH) scheduling; or

a DCI format N1 for narrow-band physical downlink shared channel (NPDSCH) scheduling.
The network device of claim 31, wherein the SIB comprises SIB1, and the at least one parameter of the DL assignment for the Msg4 comprises at least one DownlinkConfigCommon information element (IE) in SIB1.
The network device of claim 25, wherein the DL assignment for the Msg4 is deactivated or activated by the network device.
The network device of claim 25, wherein the configuration is applied at a terminal device based on determining that a reference signal received power (RSRP) of the terminal device is above a threshold configured by the network device.
The network device of any of claims 24-36, wherein the network device is further caused to:

transmit collision information related to collision of receiving Msg3 at the network device.
The network device of claim 37, wherein the collision information is transmitted in the Msg4, and the collision information comprises an indication that there is Msg3 decoding failure at the network device due to incorrect decoding of Msg3.
The network device of claim 37, wherein the Msg4 comprise at least two transport block sizes (TBSs) , and the network device is further caused to:

transmit the collision information in a second TBS of the two TBSs based on determining that there is Msg3 decoding failure at the network device due to incorrect decoding of Msg3.
The network device of claim 37, wherein the configuration is a first configuration, and the network device is further caused to:

transmitting a second configuration for a message to be transmitted on an additional resource block prior to transmitting the first configuration, wherein the message to be transmitted on the additional resource block second comprises a bitmap of RAR preambles for which valid Msg4 is available.
The network device of claim 24, wherein the first message is a MsgA in two step random access procedure, and the second message is a MsgB in two step random access procedure.
The network device of claim 41, wherein the configuration is transmitted via a system information block (SIB) , and the information at least comprises a predetermined fourth relationship between information for the MsgA and the DL assignment for the MsgB.
The network device of claim 42, wherein the fourth relationship comprises a mapping relationship between the information related to the MsgA and the DL assignment for the MsgB, and the information related to the MsgA comprises at least one of the following:

information related to physical random access channel (PRACH) preamble; or

information related to physical random access channel (PRACH) resource.

information related to physical uplink shared channel (PUSCH) transmission.
The network device of claim 42, wherein the fourth relationship comprises an offset to be applied to at least one of the following:

a time domain resource;

a frequency domain resource; or

a modulation and coding scheme (MCS) index.
The network device of claim 41, wherein the configuration is transmitted via a system information block (SIB) , and the SIB comprises at least one parameter of the DL assignment for the MsgB.
The network device of claim 24, transmitting the second message based on the configuration comprises:

transmitting the second message on a physical downlink shared channel (PDSCH) based on the configuration, and the network device is further caused to:

refrain from transmitting a downlink control information (DCI) on a physical downlink control channel (PDCCH) that schedules the PDSCH for the second message.
A method comprising:

receiving a configuration comprising information related to downlink (DL) assignment for a second message, wherein the second message comprises contention resolution;

transmitting a first message comprising a random access preamble; and

monitoring the second message based on the configuration.
A method comprising:

transmitting a configuration comprising information related to downlink (DL) assignment for a second message, wherein the second message comprises contention resolution;

receiving a first message comprising a random access preamble; and

transmitting the second message based on the configuration.
An apparatus comprising:

means for receiving a configuration comprising information related to downlink (DL) assignment for a second message, wherein the second message comprises contention resolution;

means for transmitting a first message comprising a random access preamble; and

means for monitoring the second message based on the configuration.
An apparatus comprising:

means for transmitting a configuration comprising information related to downlink (DL) assignment for a second message, wherein the second message comprises contention resolution;

means for receiving a first message comprising a random access preamble; and

means for transmitting the second message based on the configuration.
A non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method of claim 45 or 46.