Receiving a random access response with an extended response window

Abstract

Methods, apparatus and computer program products for resolving random access responses with extended response windows. A method may include: accessing a network by a user equipment by sending a random access channel preamble to a network element. The method may also include: receiving a random access response from the network element in response to the random access channel preamble. The random access response provides an indication of which random access channel opportunity in time within a span of one or more radio frames the random access response applies to.

Description

[0001] This application is a divisional application of the invention patent application with the application date of February 14, 2019, application number 201980016306.7, and invention name “Receiving a random access response with an extended response window”. Technical Field

[0002] Some example embodiments may generally relate to mobile or wireless telecommunication systems, such as long term evolution (LTE) or fifth generation (5G) radio access technology or new radio (NR) access technology, or other communication systems. For example, certain embodiments may relate to apparatus, systems and / or methods for addressing random access responses with extended response windows. Background Art

[0003] Examples of mobile or wireless telecommunication systems may include Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN), Long Term Evolution (LTE) Evolved UTRAN (E-UTRAN), Advanced LTE (LTE-A), MulteFire, LTE-A Pro and / or fifth generation (5G) radio access technology or new radio (NR) access technology. The fifth generation (5G) wireless system refers to the next generation (NG) radio system and network architecture. 5G is mainly built on the new radio (NR), but 5G (or NG) networks can also be built on the E-UTRA radio. It is estimated that NR will provide bit rates on the order of 10-20Gbit / s or higher, and will support at least enhanced mobile broadband (eMBB) and ultra-reliable low latency communication (URLLC) and massive machine type communication (mMTC). NR is expected to provide extreme broadband and ultra-robust low latency connectivity and large-scale networks to support the Internet of Things (IoT). With the increasing popularity of IoT and machine-to-machine (M2M) communications, the demand for networks that meet the requirements of low power consumption, low data rate and long battery life will increase. Note that in 5G, a node that provides radio access functionality to user equipment (i.e., similar to a Node B in UTRAN or an eNB in ​​LTE) may be named a gNB when established on an NR radio, and may be named an NG-eNB when established on an E-UTRA radio. Summary of the invention

[0004] According to some example embodiments, a method may include: sending, by a user equipment, a random access channel preamble to a network element. The method may also include: receiving a random access response from the network element in response to sending the random access channel preamble. In an example embodiment, the random access response may provide an indication of which random access channel opportunity in time within a span of one or more radio frames the random access response applies to.

[0005] According to some example embodiments, an apparatus may include means for sending a random access channel preamble to a network element. The apparatus may also include means for receiving a random access response from the network element in response to sending the random access channel preamble. In an example embodiment, the random access response may provide an indication of which random access channel opportunity in time within a span of one or more radio frames the random access response applies to.

[0006] According to some example embodiments, an apparatus may include: at least one processor and at least one memory, the at least one memory including computer program code. The at least one memory and the computer program code may be configured to, with the at least one processor, cause the apparatus to at least send a random access channel preamble to a network element. The at least one memory and the computer program code may also be configured to, with the at least one processor, cause the apparatus to at least receive a random access response from the network element in response to sending the random access channel preamble. In an example embodiment, the random access response may provide an indication of which random access channel opportunity in time within a span of one or more radio frames the random access response applies to.

[0007] According to some example embodiments, a non-transitory computer readable medium may be encoded with instructions that, when executed in hardware, may perform a method. The method may send a random access channel preamble to a network element. The method may also receive a random access response from the network element in response to sending the random access channel preamble. In an example embodiment, the random access response may provide an indication of which random access channel opportunity in time within a span of one or more radio frames the random access response applies to.

[0008] According to some example embodiments, a computer program product may perform a method. The method may send a random access channel preamble to a network element. The method may also receive a random access response from the network element in response to sending the random access channel preamble. In an example embodiment, the random access response may provide an indication of which random access channel opportunity in time within a span of one or more radio frames the random access response applies to.

[0009] According to some example embodiments, an apparatus may include circuitry configured to send a random access channel preamble to a network element. The apparatus may also include circuitry configured to receive a random access response from the network element in response to sending the random access channel preamble. In an example embodiment, the random access response may provide an indication of which random access channel opportunity in time within a span of one or more radio frames the random access response applies to.

[0010] According to some example embodiments, a method may include: receiving a random access channel preamble from a user equipment at a network element. The method may also include: sending a random access response to the user equipment in response to the random access channel preamble. In an example embodiment, the random access response may provide an indication of which random access channel opportunity in time within a span of one or more radio frames the random access response applies to.

[0011] According to some example embodiments, an apparatus may include: means for receiving a random access channel preamble from a user equipment at a network element. The apparatus may also include: means for sending a random access response to the user equipment in response to the random access channel preamble. In an example embodiment, the random access response may provide an indication of which random access channel opportunity in time within a span of one or more radio frames the random access response applies to.

[0012] According to some example embodiments, an apparatus may include: at least one processor and at least one memory, the at least one memory including computer program code. The at least one memory and the computer program code may be configured to, together with the at least one processor, cause the apparatus to at least receive a random access channel preamble from a user equipment. The at least one memory and the computer program code may also be configured to, together with the at least one processor, cause the apparatus to at least send a random access response to the user equipment in response to the random access channel preamble. In an example embodiment, the random access response may provide an indication of which random access channel opportunity in time within a span of one or more radio frames the random access response applies to.

[0013] According to some example embodiments, a non-transitory computer readable medium may be encoded with instructions that, when executed in hardware, may perform a method. The method may receive a random access channel preamble from a user equipment at a network element. The method may also send a random access response to the user equipment in response to the random access channel preamble. In an example embodiment, the random access response may provide an indication of which random access channel opportunity in time within a span of one or more radio frames the random access response applies to.

[0014] According to some example embodiments, a computer program product may perform a method. The method may receive a random access channel preamble from a user equipment at a network element. The method may also send a random access response to the user equipment in response to the random access channel preamble. In an example embodiment, the random access response may provide an indication of which random access channel timing in time within a span of one or more radio frames the random access response applies to.

[0015] According to some embodiments, an apparatus may include: circuitry configured to receive a random access channel preamble from a user equipment. The apparatus may also include: circuitry configured to send a random access response to the user equipment in response to the random access channel preamble. In an example embodiment, the random access response may provide an indication of which random access channel opportunity in time within a span of one or more radio frames the random access response applies to. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] For a proper understanding of the present invention, reference should be made to the accompanying drawings, in which:

[0017] Figure 1 An example two-step random access channel (RACH) signal flow is shown.

[0018] Figure 2 Possible response timings according to an example embodiment are shown.

[0019] Figure 3 An example flow chart of a method according to an embodiment is shown.

[0020] Figure 4 An example flow chart of another method according to an example embodiment is shown.

[0021] Figure 5a A block diagram of an apparatus according to an example embodiment is shown.

[0022] Figure 5b A block diagram of another apparatus according to an example embodiment is shown. DETAILED DESCRIPTION

[0023] It will be readily appreciated that the components of certain example embodiments, as generally described and illustrated in the figures herein, may be arranged and designed in a variety of different configurations. Therefore, the following detailed description of some example embodiments of systems, methods, apparatus, and computer program products for addressing random access responses with extended response windows is not intended to limit the scope of certain embodiments, but is representative of selected example embodiments.

[0024] The features, structures, or characteristics of the example embodiments described throughout the specification may be combined in any suitable manner in one or more example embodiments. For example, throughout the specification, the use of the phrases "certain embodiments," "an example embodiment," "some embodiments," or other similar language refers to the fact that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment. Thus, throughout the specification, the appearance of the phrases "in certain embodiments," "an example embodiment," "in some embodiments," "in other embodiments," or other similar language does not necessarily all refer to the same set of embodiments, and in one or more example embodiments, the described features, structures, or characteristics may be combined in any suitable manner.

[0025] In addition, if necessary, the different functions or steps discussed below can be performed in different orders and / or concurrently with each other. In addition, if necessary, one or more of the described functions or steps can be optional or can be combined. Like this, the following description should be considered as only the principle of some example embodiments and the explanation of teaching, rather than limitation thereof.

[0026] Certain example embodiments may relate to a random access (RA) procedure for a 3GPP New Radio (NR) design. Other example embodiments may relate to random access response (RAR) reception for an NR radio operating in an unlicensed spectrum or MsgB reception for a two-step random access (RA) procedure.

[0027] Certain proposals have been made in 3GPP with work items on NR-based access to unlicensed spectrum and on a two-step random access channel (RACH) for NR. For example, for the RA procedure, the RA may specify the required NR modifications to enhance the RACH procedure according to the agreement during the study phase, including four-step RACH modifications to handle reduced Msg 1 / 2 / 3 / 4 transmission opportunities due to listen-before-talk (LBT) failures (Radio Access Network (RAN) 1 / RAN2). In addition, for the RA procedure, LBT for two-step RACH may be provided, as well as physical random access channel (PRACH) and physical uplink shared channel (PUSCH) format improvements for NR-U to the application of two-step RACH.

[0028] For Msg2 in initial access and mobility, TR 38.889 describes that in certain cases of Msg2 transmission in four-step RACH, it may be beneficial to extend the maximum RAR window size to more than 10ms to improve the robustness against downlink (DL) LBT failures of RAR transmissions. Therefore, the ra-ResponseWindow may be extended to more than 10ms to improve the robustness of RAR transmissions in case a DL LBT failure prevents the intended transmission.

[0029] Figure 1 An exemplary two-step RACH signal flow is shown. Figure 1 Some results of the two-step RACH signal flow in NR-U SI have been documented in the Technical Report (TR) of NR-U SI. For example, for two-step RACH, msgA can be a signal for detecting user equipment (UE) and payload, while the second message can be used for contention resolution of contention-based random access (CBRA) with possible payload. MsgA can include at least the equivalent information transmitted in msg3 of four-step RACH. In addition, additional input from RAN1 may be required for the payload size of msgA.

[0030] Taking into account the above, as a baseline, all triggers for four-step RACH are applicable to two-step RACH. However, further analysis is needed on signal information (SI) requests and beam failure recovery (BFR), as well as how to obtain timing advance and authorization for msgA. In addition, contention resolution in two-step RACH can be performed by including in the first message the UE identifier that is echoed in the second message. In addition, fallback from two-step RACH to four-step RACH can be supported. For example, fallback after msgA transmission is only feasible if it is possible to detect the UE without decoding the payload, and therefore relies on such support from the physical layer. However, if two-step RACH is used for initial access, parameters for the two-step RACH process can be broadcast, including resources for msgA.

[0031] The two-step RACH process may include several objectives. One objective may specify the content of msgA to include the equivalent content of msg3 of four-step RACH (RAN2 / RAN1). Here, including uplink control information (UCI) in msgA is not excluded. Another objective may specify the content of MsgB to include the equivalent content of msg2 and msg4 of four-step RACH (RAN1 / RAN2). Another objective may specify contention resolution for two-step RACH (RAN2) and specify the design of the radio network temporary identifier (RNTI) for MsgB of two-step RACH (RAN2). In yet another objective, the fallback process may be specified as from two-step RACH to four-step RACH (RAN2 / RAN1), and all triggers of Rel-15NR four-step RACH may be applied to two-step RACH, except for the SI requirements of BFR, which depends on the discussion of RAN2. Among all the triggers of Rel-15NR four-step RACH, there is no new trigger for two-step RACH.

[0032] For contention resolution in two-step RACH, the response may be within the contention resolution timer as in four-step RACH to allow the network (NW) sufficient time to process (multiple) radio resource control (RRC) messages. In contention resolution, the value of the contention resolution timer (ra-ContentionResolutionTimer) in NRRel-15 may include: sf8; sf16; sf24; sf32; sf40; sf48; sf56; and sf64. The initial value sf8 of the contention resolution timer corresponds to 8 subframes, while the value sf16 corresponds to 16 subframes, and so on.

[0033] Since the subframe is always 1 ms in NR, the maximum value of the timer is 64 ms. In addition, the random access radio network temporary identifier (RA-RNTI) in NR Rel-15 (TS 38.321) associated with the RA preamble transmission is based on the following formula (1):

[0034] RA-RNTI=1+s_id+14×t_id+14×80×f_id+14×80×8×ul_carrier_id (1)

[0035] According to the above formula (1), the RA-RNTI associated with the PRACH / RACH opportunity for transmitting the RA preamble is calculated. In formula (1), s_id is the index of the first orthogonal frequency division multiplexing (OFDM) symbol of the specified PRACH (0≤s_id<14), t_id is the index of the first time slot of the specified PRACH in the system frame (0≤t_id<80), f_id is the index of the specified PRACH in the frequency domain (0≤f_id<8), and ul_carrier_id is the uplink (UL) carrier used for Msgl transmission (0 for the normal uplink (NUL) carrier and 1 for the supplementary uplink (SUL) carrier). Therefore, the RA-RNTI can be unique only within the span of one radio frame / system frame / system frame number duration (i.e., 10ms).

[0036] In response to a PRACH preamble transmission, the UE may attempt to detect a DCI format 1_0 with a cyclic redundancy check (CRC) scrambled by the corresponding RA-RNTI during the RAR window. If the UE detects a DCI format 1_0 and a transport block with a CRC scrambled by the corresponding RA-RNTI in the corresponding physical downlink shared channel (PDSCH) within the window, the UE may pass the transport block to a higher layer. The higher layer may then parse the transport block from the random access preamble identity (RAPID) associated with the PRACH transmission. If the higher layer identifies the RAPID in the (multiple) RAR messages of the transport block, the higher layer may indicate an UL grant to the physical layer. Such an indication may be referred to as a random access response (RAR) UL grant.

[0037] DCI for scheduling RAR with RA-RNTI in NR Rel-15 may be defined by information transmitted by means of DCI format 1_0 with CRC scrambled by RA-RNTI. One such information may include Here, if CORESET0 is configured for the cell, then is the size of CORESET 0, and if CORESET 0 is not configured for the cell, then is the size of the initial DL bandwidth portion. In addition, the time domain resource assignment may be transmitted, which may include 4 bits. In addition, the virtual resource block to physical resource block (VRB to PRB) mapping may be transmitted using 1 bit, the modulation and coding scheme may be transmitted using 5 bits, the TB scaling may be transmitted using 2 bits, and the reserved bits may include 16 bits.

[0038] The content of the RAR UL grant starting from the most significant bit (MSB) and ending with the least significant bit (LSB) may be given in the following table:

[0039] Table 1: Contents of RAR UL authorization

[0040] RAR Authorization Field Number of bits Frequency Hopping Flag 1 PUSCH frequency resource allocation 14 PUSCH time resource allocation 4 MCS 4 TPC commands for PUSCH 3 CSI Request 1

[0041] From the above, it can be seen that in the RA-RNTI calculation formula, it is unique only within the duration of the system / radio frame (10ms in NR). This means that any RO (RACH opportunity) occurring at the same time / f_id in subsequent radio frames will have the same RA-RNTI derived by the UE and used for RAR reception.

[0042] However, the current formula already results in a maximum of approximately 18,000 RA-RNTI values ​​(with a RNTI space of 64k). Therefore, it may be difficult to extend the formula so that the RO is unique with respect to the RA-RNTI in subsequent radio frames. Specifically, if a two-step MsgB addressing the RA-RNTI with a contention resolution timer of, for example, 40ms is considered, this will have completely exhausted the RNTI space, which will render the system inoperable. Therefore, at most the RA-RNTI formula can be extended to, for example, cover more frequency domain PRACH allocations than are currently available (e.g., 8 PRACH allocations), which will increase the required space more modestly - on the other hand, this will also cause problems. However, doing so does not solve the problem of response window lengths exceeding 10ms. Therefore, it may be desirable to have a RA-RNTI calculation formula that does not need to be modified to extend beyond radio frame boundaries.

[0043] According to certain example embodiments, when the ra-ResponseWindow for receiving RAR or the ra-ContentionResolutionTimer for receiving MsgB (or any other timer defined for this purpose) is configured to be greater than 10ms, the NW may indicate in the response which RO in time within a span of one or more radio frames the response applies to without extending the RN-RNTI space. In other words, the response may indicate which RO the response applies to without extending the RA-RNTI space, since different ROs may therefore use the same RA-RNTI to schedule the response. In certain example embodiments, the response may be a DCI or a RAR / MsgB.

[0044] Figure 2 1 shows possible response timings according to an example embodiment. For example, Figure 2 FIG. 4 shows possible response timings that need to indicate to which RO the response applies. Figure 2As shown, the RA-RNTI points to the RAR of RO#0 indicating whether it is for system frame number (SFN) #0, #1 or #2 RO.

[0045] According to certain example embodiments, an indication of the RO applied in response may be provided via various mechanisms. For example, in one example embodiment, an indication of the RO applied in response may be provided in the DCI that schedules the RAR / MsgB. This may utilize existing reserved bits available in the DCI format. In another example embodiment, an indication of the RO applied in response may be provided in the RAR / MsgB message itself, and / or the message may include multiple indications about multiple ROs. The advantage of this option over providing an indication in the DCI that schedules the RAR / MsgB is that multiple ROs may be responded to in a single RAR / MsgB. However, a disadvantage may be that the UE may have to decode the media access control (MAC) protocol data unit (PDU) before determining whether the response message corresponds to the RO in which the preamble is transmitted. In another example embodiment, the NW may configure which of the above mechanisms is used.

[0046] In certain example embodiments, the indication in the response provided by the NW may include various contents. For example, in one example embodiment, the indication may include the LSB of the SFN preceding the response message scheduling, or the LSB of the SFN including the PRACH resource / RACH opportunity (RO) in which the preamble is transmitted. For example, 3 LSBs may allow the RO within 8 radio frames (i.e., 80ms) to be indicated using the same RA-RNTI. This will also cover the maximum ra-ContentionResolutionTimer value defined in Rel-15.

[0047] In another example embodiment, the indication may simply be an index offset in radio frames relative to the radio frame in which the response message is scheduled. For example, index offset #0 represents the current radio frame (i.e., the same radio frame in which the response message is scheduled), #1 represents the previous radio frame, and so on. Furthermore, the network may configure whether the UE should decode the indication, or alternatively, the UE may determine this based on the configured ra-ResponseWindow and / or ra-ContentionResolutionTimer length (i.e., if configured to be greater than 10ms).

[0048] Additionally or alternatively, in another example embodiment, if there are more than 8 ROs on a frequency at a certain point in time, the same RA-RNTI may also be applied in the frequency domain. Here, the DCI of the scheduling response message or the response message itself may indicate which RO on the frequency the response applies to. This indication may be a supplement or alternative to the time domain indication.

[0049] According to certain example embodiments, the indication may include a one-bit indication that 16 RO / PRACHs on frequency may be allowed. This may be done because setting this bit will indicate RO 8-15 in the frequency domain, and the actual index between the two may be obtained by considering the actual f_id used in the RA-RNTI formula. For example, setting this bit indicates f_id=8+f_id.

[0050] Figure 3 An example flow chart of a method according to an example embodiment is shown. In some example embodiments, Figure 3 The flowchart may be executed by a mobile station and / or a UE, for example. According to one embodiment, Figure 3 The method may include initially, at 300, accessing a network by sending a random access channel preamble to a network element. The method may also include, at 305, receiving a random access response from the network element in response to the random access channel preamble. In an example embodiment, the random access response may provide an indication of which random access channel opportunity in time within a span of one or more radio frames the random access response applies to.

[0051] Figure 4 An example flow chart of another method according to an example embodiment is shown. In some example embodiments, Figure 4 The flowchart may be executed by a network entity or a network node in a 3GPP system (such as LTE or 5GNR). For example, in some example embodiments, Figure 4 The method can be performed by a base station, an eNB or a gNB.

[0052] According to an example embodiment, Figure 4 The method may include: initially, at 400, receiving a random access channel preamble from a user equipment. The method may also include: sending a random access response to the user equipment in response to the random access channel preamble at 405. According to an example embodiment, the random access response may provide an indication of which random access channel opportunity in time within a span of one or more radio frames the random access response applies to.

[0053] In an example embodiment, the window for receiving a random access response may be greater than 10ms. In another example embodiment, the indication may be provided in the downlink control information that schedules the random access response. In another example embodiment, the indication may be provided in the random access response itself, and the random access response may include multiple indications about multiple random access channel opportunities. According to another example embodiment, the indication may include multiple least significant bits of a system frame number before the random access response is scheduled, or multiple least significant bits of multiple system frame numbers of physical random access channel resources. In another example embodiment, the indication may include an index offset in a radio frame relative to the radio frame in which the random access response is scheduled. According to another example embodiment, when there are more than 8 random access channels on a frequency, the same random access radio network temporary identifier may be applied in the frequency domain.

[0054] Figure 5a An example of an apparatus 10 according to another embodiment is shown. In one embodiment, the apparatus 10 may be a node or element in a communication network or associated with such a network, such as a UE, a mobile equipment (ME), a mobile station, a mobile device, a fixed device, an IoT device, or other device. As described herein, a UE may alternatively be referred to as, for example, a mobile station, a mobile device, a mobile unit, a mobile device, a user equipment, a subscriber station, a wireless terminal, a tablet computer, a smart phone, an IoT device, a sensor, or a NB-IoT device, etc. As an example, the apparatus 10 may be implemented, for example, in a wireless handheld device, a wireless plug-in accessory, etc.

[0055] In some example embodiments, the apparatus 10 may include one or more processors, one or more computer-readable storage media (e.g., memory, storage, etc.), one or more radio access components (e.g., modems, transceivers, etc.), and / or a user interface. In some embodiments, the apparatus 10 may be configured to operate using one or more radio access technologies, such as GSM, LTE, LTE-A, NR, 5G, WLAN, WiFi, NB-IoT, Bluetooth, NFC, MulteFire, and / or any other radio access technology. It should be noted that a person of ordinary skill in the art will understand that the apparatus 10 may include Figure 5a Components or features not shown.

[0056] like Figure 5aAs shown in the example of , the device 10 may include or be coupled to a processor 12 for processing information and executing instructions or operations. The processor 12 may be any type of general or special purpose processor. In practice, for example, the processor 12 may include one or more of the following: a general purpose computer, a special purpose computer, a microprocessor, a digital signal processor (DSP), a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), and a processor based on a multi-core processor architecture. Although in Figure 5a A single processor 12 is shown in FIG. 1 , but multiple processors may be utilized according to other embodiments. For example, it should be understood that in certain example embodiments, the apparatus 10 may include two or more processors, which may form a multiprocessor system that may support multiprocessing (e.g., in which case the processor 12 may represent a multiprocessor). According to certain example embodiments, the multiprocessor system may be tightly coupled or loosely coupled (e.g., to form a computer cluster).

[0057] Processor 12 may perform functions associated with the operation of device 10, including, as some examples, precoding of antenna gain / phase parameters, encoding and decoding of individual bits that form communication messages, formatting of information, and overall control of device 10, including processes associated with management of communication resources.

[0058] The device 10 may also include or be coupled to a memory 14 (internal or external) for storing information and instructions that can be executed by the processor 12, and the memory 14 may be coupled to the processor 12. The memory 14 may be one or more memories and of any type suitable for the local application environment, and may be implemented using any suitable volatile or non-volatile data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and / or removable memory. For example, the memory 14 may include any combination of the following: random access memory (RAM), read-only memory (ROM), static storage (such as a magnetic disk or optical disk), hard disk drive (HDD), or any other type of non-transient machine or computer readable medium. The instructions stored in the memory 14 may include program instructions or computer program codes that, when executed by the processor 12, enable the device 10 to perform the tasks described herein.

[0059] In one embodiment, the device 10 may also include or be coupled to a (internal or external) drive or port configured to accept and read an external computer-readable storage medium, such as an optical disk, a USB drive, a flash drive, or any other storage medium. For example, the external computer-readable storage medium may store a computer program or software for execution by the processor 12 and / or the device 10.

[0060] In some embodiments, the device 10 may also include or be coupled to one or more antennas 18 for receiving downlink signals and for transmitting from the device 10 via an uplink. The device 10 may also include a transceiver 18 configured to transmit and receive information. The transceiver 28 may also include a radio interface (e.g., a modem) coupled to the antenna 15. The radio interface may correspond to a variety of radio access technologies, including one or more of the following: GSM, LTE, LTE-A, 5G, NR, WLAN, NB-IoT, Bluetooth, BT-LE, NFC, RFID, UWB, etc. The radio interface may include other components, such as filters, converters (e.g., digital-to-analog converters, etc.), symbol demappers, signal shaping components, inverse fast Fourier transform (IFFT) modules, etc., to process symbols carried by the downlink or uplink, such as OFDMA symbols.

[0061] For example, the transceiver 18 may be configured to modulate information onto a carrier waveform for transmission by (multiple) antennas 15, and demodulate information received via (multiple) antennas 15 for further processing by other elements of the device 10. In other embodiments, the transceiver 18 may be capable of directly transmitting and receiving signals or data. Additionally or alternatively, in some embodiments, the device 10 may include input and / or output devices (I / O devices). In some embodiments, the device 10 may also include a user interface, such as a graphical user interface or a touch screen.

[0062] In one embodiment, the memory 14 stores software modules that provide functionality when executed by the processor 12. For example, the modules may include an operating system that provides operating system functionality for the device 10. The memory may also store one or more functional modules (such as applications or programs) to provide additional functionality for the device 10. The components of the device 10 may be implemented in hardware or any suitable combination of hardware and software. According to an example embodiment, the device 10 may optionally be configured to communicate with the device 20 via a wireless or wired communication link 70 according to any radio access technology (such as NR).

[0063] According to some example embodiments, processor 12 and memory 14 may be included in a processing circuit system or a control circuit system, or may form a part of a processing circuit system or a control circuit system. In addition, in some embodiments, transceiver 28 may be included in a transceiver circuit system, or may form a part of a transceiver circuit system.

[0064] As described above, according to some example embodiments, the apparatus 10 may be, for example, a UE, a mobile device, a mobile station, a ME, an IoT device, and / or an NB-IoT device. According to some embodiments, the apparatus 10 may be controlled by the memory 14 and the processor 12 to perform functions associated with the example embodiments described herein. For example, in some embodiments, the apparatus 10 may be configured to perform any of the flow charts or signaling diagrams described herein (such as Figure 1 , 2 One or more of the processes depicted in the flowcharts shown in and 3).

[0065] For example, in one embodiment, the apparatus 10 may be controlled by the memory 14 and the processor 12 to access the network by sending a random access channel preamble to the network element. The apparatus 14 may also be controlled by the memory 14 and the processor 12 to receive a random access response from the network element in response to sending the random access channel preamble. In an example embodiment, the random access response may provide an indication of which random access channel opportunity in time within a span of one or more radio frames the random access response applies to.

[0066] Figure 5b An example of an apparatus 20 according to an example embodiment is shown. In an example embodiment, the apparatus 20 may be a node, host, or server in a communication network or serving such a network. For example, the apparatus 20 may be a satellite, a base station, a Node B, an evolved Node B (eNB), a 5G Node B or access point, a next generation Node B (NG-NB or gNB), and / or a WLAN access point associated with a radio access network (RAN) such as an LTE network, 5G, or NR. In certain example embodiments, the apparatus 20 may be an eNB in ​​LTE or a gNB in ​​5G.

[0067] It should be understood that in some example embodiments, the device 20 may include an edge cloud server as a distributed computing system, where the server and the radio node may be independent devices that communicate with each other via a radio path or via a wired connection, or they may be located in the same entity that communicates via a wired connection. For example, in certain example embodiments where the device 20 represents a gNB, it may be configured as a central unit (CU) and distributed unit (DU) architecture that divides the gNB functionality. In such an architecture, the CU may be a logical node that includes gNB functionality (such as transmission of user data, mobility control, radio access network sharing, positioning and / or session management, etc.). The CU may control the operation of (multiple) DUs via a fronthaul interface. Depending on the functional splitting option, the DU may be a logical node that includes a subset of gNB functionality. It should be noted that a person of ordinary skill in the art will understand that the device 20 may include Figure 5b Components or features not shown.

[0068] As in Figure 5b As shown in the example of , the device 20 may include a processor 22 for processing information and executing instructions or operations. The processor 22 may be any type of general or special purpose processor. For example, as an example, the processor 22 may include one or more of the following: a general purpose computer, a special purpose computer, a microprocessor, a digital signal processor (DSP), a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), and a processor based on a multi-core processor architecture. Although in Figure 5b A single processor 22 is shown in FIG. 1 , but multiple processors may be utilized according to other embodiments. For example, it should be understood that in some embodiments, the apparatus 20 may include two or more processors, which may form a multiprocessor system that may support multiprocessing (e.g., in which case, the processor 22 may represent a multiprocessor). In some embodiments, the multiprocessor system may be tightly coupled or loosely coupled (e.g., to form a computer cluster).

[0069] According to certain example embodiments, processor 22 may perform functions associated with the operation of device 20, which may include, for example, precoding of antenna gain / phase parameters, encoding and decoding of individual bits that form communication messages, formatting of information, and overall control of device 20, including processes related to management of communication resources.

[0070] The device 20 may also include or be coupled to a memory 24 (internal or external), the memory 24 being used to store information and instructions that can be executed by the processor 22, and the memory 24 may be coupled to the processor 22. The memory 24 may be one or more memories and of any type suitable for the local application environment, and may be implemented using any suitable volatile or non-volatile data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and / or removable memory. For example, the memory 24 may include any combination of the following: random access memory (RAM), read-only memory (ROM), static memory (such as a magnetic disk or optical disk), hard disk drive (HDD), or any other type of non-transient machine or computer readable medium. The instructions stored in the memory 24 may include program instructions or computer program codes that, when executed by the processor 22, enable the device 20 to perform the tasks described herein.

[0071] In one embodiment, the device 20 may also include or be coupled to a (internal or external) drive or port configured to accept and read an external computer-readable storage medium, such as an optical disk, a USB drive, a flash drive, or any other storage medium. For example, the external computer-readable storage medium may store a computer program or software for execution by the processor 22 and / or the device 20.

[0072] In certain example embodiments, the apparatus 20 may also include or be coupled to one or more antennas 25 for transmitting signals and / or data to and receiving signals and / or data from the apparatus 20. The apparatus 20 may also include or be coupled to a transceiver 28 configured to transmit and receive information. The transceiver 28 may include, for example, a plurality of radio interfaces that may be coupled to the (multiple) antennas 25. The radio interfaces may correspond to a variety of radio access technologies, including one or more of the following: GSM, NB-IoT, LTE, 5G, WLAN, Bluetooth, BT-LE, NFC, Radio Frequency Identifier (RFID), Ultra-Wideband (UWB), MulteFire, etc. The radio interfaces may include components (such as filters, converters (e.g., digital-to-analog converters, etc.), mappers, Fast Fourier Transform (FFT) modules, etc.) to generate symbols for transmission via one or more downlinks and receive symbols (e.g., via uplinks).

[0073] Thus, the transceiver 28 may be configured to modulate information onto a carrier waveform for transmission by the antenna(s) 25, and to demodulate information received via the antenna(s) 25 for further processing by other elements of the apparatus 20. In other embodiments, the transceiver 18 may be capable of directly transmitting and receiving signals or data. Additionally or alternatively, in some embodiments, the apparatus 20 may include input and / or output devices (I / O devices).

[0074] In one embodiment, memory 24 may store software modules that provide functionality when executed by processor 22. These modules may include, for example, an operating system that provides operating system functionality for device 20. The memory may also store one or more functional modules (such as applications or programs) to provide additional functionality to device 20. The components of device 20 may be implemented in hardware or any suitable combination of hardware and software.

[0075] According to some embodiments, processor 22 and memory 24 may be included in a processing circuit system or a control circuit system, or may form a part of a processing circuit system or a control circuit system. In addition, in some embodiments, transceiver 28 may be included in a transceiver circuit system, or may form a part of a transceiver circuit system.

[0076] As used herein, the term "circuitry" may refer to a hardware-only implementation of circuitry (e.g., analog and / or digital circuitry), a combination of hardware circuitry and software, a combination of analog and / or digital hardware circuitry and software / firmware, any portion of a hardware processor(s) (including a digital signal processor) with software that works together to enable a device (e.g., device 20) to perform various functions, and / or hardware circuit(s) and / or processor(s), or portions thereof, that operate using software, but may not be present when the software is not required for operation. As another example, as used herein, the term "circuitry" may also cover an implementation of a hardware circuit or processor (or multiple processors), or a portion of a hardware circuit or processor, and its accompanying software and / or firmware. The term circuitry may also cover, for example, a baseband integrated circuit in a server, a cellular network node or device, or other computing or network device.

[0077] As described above, in some embodiments, the device 20 may be a network node or a RAN node, such as a base station, an access point, a Node B, an eNB, a gNB, a WLAN access point, etc. According to some embodiments, the device 10 may be controlled by the memory 24 and the processor 22 to perform functions associated with any of the embodiments described herein, such as Figure 1 , 2 and the flow chart or signaling diagram shown in 4.

[0078] For example, in one embodiment, the apparatus 20 may be controlled by the memory 24 and the processor 22 to receive a random access channel preamble from a user equipment to access a network. The apparatus 24 may also be controlled by the memory 24 and the processor 22 to send a random access response to the user equipment in response to the random access channel preamble. In an example embodiment, the random access response may provide an indication of which random access channel opportunity in time within a span of one or more radio frames the random access response applies to.

[0079] Certain example embodiments described herein provide several technical improvements, enhancements and / or advantages. For example, according to certain example embodiments, the RA-RNTI formula defined in Rel-15 NR may be applied as is. Alternatively, the RA-RNTI formula defined in Rel-15 NR may not need to be extended at least in the time domain, which can significantly save unnecessary RA-RNTI allocations when extending the RA response window length or introducing a long contention resolution window for MsgB.

[0080] In some example embodiments, the functionality of any method, process, signaling diagram, algorithm or flow chart described herein may be implemented by software and / or computer program code or portion of code stored in a memory or other computer-readable or tangible medium and executed by a processor.

[0081] In some example embodiments, an apparatus may include or be associated with at least one software application, module, unit, or entity configured to be executed by at least one operating processor (multiple) arithmetic operations or a program or portion thereof (including added or updated software routines). A program (also referred to as a program product or computer program, including software routines, applets, and macros) may be stored in any apparatus-readable data storage medium and includes program instructions for performing specific tasks.

[0082] A computer program product may include one or more computer executable components that are configured to perform some example embodiments when the program is run. The one or more computer executable components may be at least one software code or part thereof. Modifications and configurations required to implement the functionality of the example embodiments may be performed as (multiple) routines, which may be implemented as (multiple) added or updated software routines. (Multiple) software routines may be downloaded to a device.

[0083] As an example, the software or computer program code or part thereof may be in source code form, object code form or some intermediate form and may be stored in some carrier, distribution medium or computer readable medium, which may be any entity or device capable of carrying the program. Such carriers may include, for example, recording media, computer memory, read-only memory, optoelectronic and / or electrical carrier signals, telecommunication signals and software distribution packages. Depending on the processing power required, the computer program may be executed in a single electronic digital computer or distributed among multiple computers. The computer readable medium or computer readable storage medium may be a non-transient medium.

[0084] In other example embodiments, the function may be performed by hardware or circuitry included in a device (e.g., device 10 or device 20), such as by using an application specific integrated circuit (ASIC), a programmable gate array (PGA), a field programmable gate array (FPGA), or any other combination of hardware and software. In yet another embodiment, the function may be implemented as a signal, an intangible means that may be carried by an electromagnetic signal downloaded from the Internet or other network.

[0085] According to example embodiments, an apparatus (such as a node, a device or a corresponding component) may be configured as a circuit system, a computer or a microprocessor (such as a single-chip computer element) or a chipset, including at least a memory and an operation processor, wherein the memory is used to provide storage capacity for arithmetic operations and the operation processor is used to perform arithmetic operations.

[0086] Those skilled in the art will readily appreciate that the present invention as described above may be practiced with steps in a different order and / or with hardware elements in a configuration different from that disclosed. Therefore, although the present invention has been described based on these preferred embodiments, it is clear to those skilled in the art that certain modifications, variations, and alternative constructions will be clear without departing from the spirit and scope of the present invention. Although the above embodiments relate to 5GNR and LTE technologies, the above embodiments may also be applied to any other current or future 3GPP technologies, such as advanced LTE and / or fourth generation (4G) technologies.

[0087] Partial Glossary

[0088] DCI Downlink Control Information

[0089] eNB Enhanced Node B (LTE base station)

[0090] gNB 5G or NR base station

[0091] LBT Listen before you speak

[0092] LSB Least Significant Bit

[0093] LTE Long Term Evolution

[0094] MU Multi-User

[0095] NW Network

[0096] NR New Radio

[0097] NR-U New Radio Unlicensed

[0098] PRACH Physical Random Access Channel

[0099] PRB Physical Resource Block

[0100] RA Random Access

[0101] RACH Random Access Channel

[0102] RAR Random Access Response

[0103] RNTI Radio Network Temporary Identifier

[0104] RO RACH Timing

[0105] SFN System Frame Number

[0106] UE User Equipment

[0107] UL Uplink.

Claims

1. A method for communication, the method comprising: sending, by the user equipment to the network element, a transmission including a random access channel preamble; responsive to sending the transmission including the random access channel preamble, receiving downlink control information from the network element, the downlink control information for scheduling a random access response associated with the transmission; and Only when the window for receiving the random access response is configured to be greater than 10 ms, the user equipment determines to decode the indication in the downlink control information, in: The indication indicates a random access channel opportunity to which the random access response applies, and The indication comprises a plurality of least significant bits of a system frame number corresponding to the random access channel opportunity in which the preamble was transmitted.

2. The method according to claim 1, wherein the random access response is included in message 2 in a four-step random access procedure, or is included in message B in a two-step random access procedure.

3. A method according to any preceding claim, wherein the indication indicates the random access channel opportunity in time within a span of one or more radio frames.

4. A user equipment, comprising: at least one processor; as well as at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the user equipment to at least: sending a transmission including a random access channel preamble to a network element; responsive to sending the transmission including the random access channel preamble, receiving downlink control information from the network element, the downlink control information for scheduling a random access response associated with the transmission; and determining to decode the indication in the downlink control information only when the window for receiving the random access response is configured to be greater than 10 ms, in: The indication indicates a random access channel opportunity to which the random access response applies, and The indication comprises a plurality of least significant bits of a system frame number corresponding to the random access channel opportunity in which the preamble was transmitted.

5. The user equipment according to claim 4, wherein the random access response is included in message 2 in a four-step random access procedure, or is included in message B in a two-step random access procedure.

6. The user equipment according to any one of claims 4 to 5, wherein the indication indicates the random access channel opportunity in time within a span of one or more radio frames.

7. A method for communication, the method comprising: receiving, at a network element, a transmission from a user equipment including a random access channel preamble; In response to the transmission including the random access channel preamble, sending, by the network element to the user equipment, downlink control information for scheduling a random access response associated with the transmission; and determining, at the user equipment, to decode the indication in the downlink control information only when the window for receiving the random access response is configured to be greater than 10 ms, in: The indication indicates a random access channel opportunity to which the random access response applies, and The indication comprises a plurality of least significant bits of a system frame number corresponding to the random access channel opportunity in which the preamble was transmitted.

8. The method of claim 7, wherein the random access response is included in message 2 in a four-step random access procedure, or is included in message B in a two-step random access procedure.

9. The method according to any one of claims 7 to 8, wherein the indication indicates the random access channel opportunity in time within a span of one or more radio frames.

10. The method according to any one of claims 7 to 8, wherein the method comprises configuring, by the network element, the length of the window for receiving the random access response at the user equipment.

11. A system for communication, the system comprising a network element and a user equipment, The network elements include: at least one processor; as well as at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the network element to at least: receiving a transmission including a random access channel preamble from the user equipment; and sending, in response to the transmission including the random access channel preamble, downlink control information to the user equipment, the downlink control information being used to schedule a random access response associated with the transmission, The user equipment is configured to: determine to decode the indication in the downlink control information only when the window for receiving the random access response is configured to be greater than 10 ms, in: The downlink control information includes an indication of a random access channel opportunity to which the random access response applies, and The indication comprises a plurality of least significant bits of a system frame number corresponding to the random access channel opportunity in which the preamble was transmitted.

12. The system of claim 11, wherein the random access response is included in message 2 in a four-step random access procedure, or is included in message B in a two-step random access procedure.

13. The system of any one of claims 11 to 12, wherein the indication indicates the random access channel opportunity in time within a span of one or more radio frames.

14. The system according to any one of claims 11 to 12, wherein the network element is configured to configure a length of the window for receiving the random access response at the user equipment.

15. An apparatus for communication, the apparatus comprising means for performing a method according to any one of claims 1-3 or 7-10.

16. An apparatus for communication, the apparatus comprising circuitry configured to cause the apparatus to perform the method according to any one of claims 1-3 or 7-10.

17. A computer program product for communication, comprising a computer program, characterized in that The computer program implements the steps of the method according to any one of claims 1-3 or 7-10 when executed by a processor.

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