CN111937478B - Backup configuration during random access - Google Patents

Abstract

Embodiments of the present disclosure relate to a method, apparatus, and computer-readable storage medium for backup configuration in a Random Access (RA) procedure. In an example embodiment, a terminal device is configured with a first Coverage Enhancement (CE) mode. The terminal device initiates the RA procedure in a second CE mode different from the first CE mode. During the random access procedure, the terminal device determines whether dedicated backup configuration is enabled. If it is determined that the dedicated backup configuration is enabled, the terminal device detects a message from the network device by using the dedicated backup configuration to make the RA procedure more efficient and effective.

Description

Backup configuration during random access

technical field

Embodiments of the present disclosure generally relate to the field of communications, and in particular to methods, devices and computer-readable storage media for backup configuration in random access (RA) procedures.

Background technique

In the 3rd Generation Partnership Project (3GPP) specification, a coverage enhancement (CE) level has been proposed for a user equipment (UE) in a random access (RA) procedure to achieve enhanced coverage. For example, four CE levels are designated for different coverage areas. The UE may select a CE level from four CE levels for these CE levels based on the serving cell's Reference Signal Received Power (RSRP) measurement and the broadcasted RSRP threshold. If RA attempts at the selected CE level have failed several times, the UE may increase the CE level and initiate additional RA attempts at the increased CE level until the maximum allowed number of attempts is reached.

For an RRC_CONNECTED UE (RRC connected UE) in a radio resource control (RRC) connected state, two CE modes are proposed, which are referred to as CE mode A and CE mode B, respectively. CE pattern A corresponds to CE level 0 and CE level 1, and specifies a set of behaviors with no or few repetitions. CE pattern B corresponds to CE level 2 and CE level 3, and specifies another set of behaviors, which has a large number of repetitions. A specific CE mode can be explicitly configured to the UE via dedicated RRC signaling.

During the RA procedure of the RRC_CONNECTED UE, the UE may also increase the CE level after a failed RA attempt with a lower CE level. CE levels can be increased across different CE modes. For example, if an RA attempt in CE mode A fails, the UE may switch to CE level 2 or 3 for CE mode B to initiate additional RA attempts.

Contents of the invention

In general, example embodiments of the present disclosure provide a method, device and computer-readable storage medium for backup configuration in an RA process.

In a first aspect, a method at a terminal device is provided. The terminal device is configured with a first CE mode. The terminal device initiates a random access procedure in a second CE mode different from the first CE mode. During the random access procedure, the terminal device determines whether a dedicated backup configuration is enabled. If it is determined that the dedicated fallback configuration is enabled, the terminal device detects the message from the network device by using the dedicated fallback configuration.

In a second aspect there is provided an apparatus comprising at least one processor and at least one memory comprising computer program code. The at least one memory and computer program code are configured to, with at least one processor, cause the device to: initiate a random access procedure in a second CE mode different from the configured first CE mode; and during the random access procedure, determine Whether the dedicated fallback configuration is enabled, and in response to determining that the dedicated fallback configuration is enabled, detecting a message from the network device using the dedicated fallback configuration.

In a third aspect there is provided a computer readable storage medium having a computer program stored thereon. The computer program, when executed by a processor, causes the processor to perform the method according to the first aspect.

It should be understood that this Summary is not intended to identify key features or essential features of the embodiments of the disclosure, nor is it intended to be used to limit the scope of the disclosure. Other features of the present disclosure will become readily understood through the following description.

Description of drawings

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

FIG. 1 shows an example interaction process between a terminal device and a network device in a traditional RA process;

Figure 2 illustrates an example communication network in which embodiments of the present disclosure may be implemented;

Figure 3 shows a flowchart of an example method according to some embodiments of the present disclosure; and

Figure 4 shows a simplified block diagram of a device suitable for implementing embodiments of the present disclosure.

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

Detailed ways

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

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

As used herein, the term "communication network" refers to a network that follows any suitable communication standard or protocol, such as Long Term Evolution (LTE), LTE-Advanced (LTE-A) and 5G NR, and employs any suitable Communication technologies including, for example, Multiple Input Multiple Output (MIMO), OFDM, Time Division Multiplexing (TDM), Frequency Division Multiplexing (FDM), Code Division Multiplexing (CDM), Bluetooth, ZigBee, Machine Type Communication (MTC), eMBB , mMTC and uRLLC technologies.

As used herein, the term "network device" refers to any suitable device on the network side of a communications network. The network equipment may include any suitable equipment in the access network of the communication network, including, for example, a base station (BS), a relay, an access point (AP), a Node B (NodeB or NB), an evolved NodeB (eNodeB or eNB ), Gigabit NodeB (gNB), Remote Radio Unit (RRU), Radio Head (RH), Remote Radio Head (RRH), low power nodes (such as femto nodes, pico nodes, etc.). For discussion purposes, in some embodiments, an eNB is used as an example of a network device.

As used herein, the term "terminal device" refers to a device that can be configured, arranged and/or operable to communicate with a network device or another terminal device in a communication network. This communication may involve the transmission and/or reception of wireless signals using electromagnetic signals, radio waves, infrared signals and/or other types of signals suitable for conveying information over the air. In some embodiments, end devices may be configured to transmit and/or receive information without direct human interaction. For example, when triggered by an internal or external event, or in response to a request from the network side, the terminal device may transmit information to the network device according to a predetermined schedule.

Examples of end devices include, but are not limited to, user equipment (UE), such as smartphones, wireless-enabled tablets, laptop embedded equipment (LEE), laptop mounted equipment (LME), and/or wireless customer premises Equipment (CPE). For discussion purposes, in the following some embodiments will be described with reference to a UE as an example of a terminal device, and the terms "terminal device" and "user equipment" (UE) may be used interchangeably in the context of this disclosure.

As used herein, the term "circuitry" may refer to one or more or all of the following:

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

(b) combinations of hardware circuits and software, such as (where applicable): (i) analog and/or digital hardware circuit(s) combined with software/firmware, and (ii) hardware(s) with software any part of a processor (including digital signal processor(s), software, and memory(s) that work together to enable a device such as a mobile phone or server to perform various functions); and

(c) hardware circuit(s) and/or processor(s), such as microprocessor(s) or part of a microprocessor(s), which require software (e.g. firmware) to operate, but The software may not be present when it is not required 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 merely a hardware circuit or processor (or processors), or a hardware circuit or processor and its (or their) accompanying software and and/or the implementation of part of the firmware. The term circuitry also covers baseband integrated circuits or processor integrated circuits used in mobile devices, or similar integrated circuits in servers, cellular network equipment, or other computing or network equipment, for example and where applicable to specific claim elements .

As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. The term "comprising" and variations thereof are to be read as open terms meaning "including but not limited to". The term "based on" is to be read as "based at least in part on". The terms "one embodiment" and "an embodiment" are to be read as "at least one embodiment." The term "another embodiment" is to be read as "at least one other embodiment". Other definitions (both explicit and implicit) may be included below.

As mentioned above, two CE modes, CE mode A and CE mode B, have been proposed for RRC_CONNECTED UE. The UE may use one or more of the CE levels corresponding to the two CE modes during the RA procedure. For example, an enhanced machine type communication (eMTC) UE may try RA at several CE levels during a radio access channel (RACH) procedure. If the UE is configured with CE mode A, the UE may initiate a RACH procedure in CE mode A, for example, after reaching the maximum number of scheduling requests (SR-MAX). When the UE fails to perform RA in CE mode A, the UE may select CE level 2 or 3 corresponding to CE mode B to send another RA preamble.

Traditionally, during the RACH procedure, the UE may use a common configuration for the selected CE level, such as a Common Search Space (CSS) for a Machine Type Communication Physical Downlink Control Channel (MPDCCH) search space. For contention resolution purposes, after Message 3 (Msg3) is successfully transmitted to the eNB, UEs configured with CE Mode A fall back to a dedicated configuration for CE Mode A such as user-specific configuration for MPDCCH search space. Search space (USS) for further communication.

Figure 1 shows an example interaction process 100 between a UE and an eNB in a conventional RA procedure. In this example, the UE is configured with CE Mode A. After the RA attempt in CE mode A has failed, the UE selects CE level 2 or CE level 3 corresponding to CE mode B. Then, as shown, the UE sends (105) Message 1 (Msg1) containing the RA preamble to the eNB with the selected CE level 2 or CE level 3, and the eNB then sends (110) Message 2 (Msg2) as a random Access Response (RAR). Upon receiving Msg2, the UE sends (115) Message 3 (Msg3) with a Cell Radio Network Temporary Identifier (C-RNTI).

In this example, the transmission of Msg3 failed. The UE performs a retransmission of Msg3 (120). During the retransmission (120) of Msg3, the eNB sends (120a) an uplink (UL) grant scrambled by a temporary C-RNTI. The UE may use CSS for CE Mode B to detect UL grants. Upon receiving the UL grant, the UE sends (120b) Msg3 to the eNB. After successful transmission or retransmission of Msg3, eNB sends (125) UL grant scrambled by C-RNTI in MPDCCH. At this point, the UE falls back to CE mode A and uses the dedicated configuration for CE mode A to detect UL grants. The UE then initiates (130) a transmission on a Physical Uplink Shared Channel (PUSCH) based on the UL grant.

The inventors found that different CE modes usually have different configurations, such as the maximum repetition number (R-max) for MPDCCH/PUCCH/PUSCH/Physical Downlink Shared Channel (PDSCH). CE Mode-A specific configurations are sometimes not robust to transmissions in CE Mode B. For example, in the RA procedure shown in Figure 1, using a dedicated configuration for CE Mode A, MPDCCH transmission (125) and PUSCH transmission (130) may not be successful in poor coverage of the eNB.

In this case, the UE may have to retransmit a Radio Link Control (RLC) Protocol Data Unit (PDU). After the maximum number of RLC retransmissions is finally reached, a radio link failure will be declared. This may result in wasted resources, data interruption, more power consumption, etc. Meanwhile, the transmission of the RRC reconfiguration message may fail even when the eNB wants to reconfigure CE mode B to the UE due to insufficient CE mode-A configuration in poor coverage.

Embodiments of the present disclosure provide an improved RA procedure for a terminal device. A terminal device configured with one CE mode initiates an RA procedure with another CE mode. During the RA procedure, the end device determines whether a dedicated backup configuration is enabled. If it is determined that the dedicated fallback configuration is enabled, the terminal device detects the message from the network device by using the dedicated fallback configuration.

In various embodiments of the present disclosure, a dedicated backup configuration may be used by the terminal device during the RA procedure, if desired. In this way, the terminal device can switch to a configuration mode more suitable for radio conditions in time without waiting for CE mode reconfiguration from the network side, thereby making the RA process more effective and efficient. Additionally, network resources and UE power can be saved by disabling inappropriate CE mode configurations.

FIG. 2 illustrates an example communication network 200 in which embodiments of the present disclosure may be implemented. The network 200 includes a terminal device 210 and a network device 220 . It should be understood that the numbers of network devices and terminal devices are shown for illustrative purposes only, without imposing any limitation. Network 200 may include any suitable number of network devices and end devices.

The terminal device 210 can communicate with the network device 220 via the network device 220 or with another terminal device (not shown). Communications may utilize any suitable technology that already exists or will be developed in the future. In some embodiments, the terminal device 210 may be implemented by an eMTC UE, and the eMTC UE communicates with or via the network device 220 using MTC and/or eMTC technology.

In various embodiments of the present disclosure, end device 120 is configured with a CE mode and a dedicated fallback configuration. During an RA procedure initiated in an additional CE mode, a dedicated backup configuration may be used by the terminal device 120 to improve the RA procedure.

FIG. 3 shows a flowchart of an example method 300 according to some embodiments of the present disclosure. The method 300 can be implemented at the terminal device 210 as shown in FIG. 2 . For purposes of discussion, method 300 will be described with reference to FIG. 2 .

At block 305, a terminal device 210 configured with one CE mode (referred to as a first CE mode) initiates a random access procedure with a different CE mode (referred to as a second CE mode). The first CE mode and the second CE mode may be implemented by any suitable CE mode. In some embodiments, the terminal device 210 is in an RRC connected state, and the first CE mode and the second CE mode are CE mode A and CE mode B for the RRC connected state.

In some embodiments, prior to initiating the RA procedure at block 305, the terminal device 210 may initiate the RA procedure in the first mode. After the RA procedure in the first mode has failed, the terminal device 210 may initiate the RA procedure in the second CE mode. In some other embodiments, the terminal device 210 may directly use the second CE mode to initiate the RA process. For example, in case the terminal device 220 is configured with CE mode A (as the first CE mode), if the terminal device 220 moves to an area in poor coverage of the network device 220, the terminal device 220 may choose to use CE mode B (as the second CE mode) to initiate the RA procedure.

At block 310, the terminal device 210 determines whether a dedicated fallback configuration is enabled. The dedicated backup configuration may be configured by network device 220, for example, before the RA procedure is initiated. For example, a dedicated backup configuration may be configured with RRC signaling or a separate RRC reconfiguration message together with configuration or parameters related to the first CE mode. In addition, private backup configurations can be reconfigured.

The dedicated fallback configuration may comprise any suitable parameters other than those related to the first CE mode. In some embodiments, a dedicated fallback configuration may be associated with the second CE mode. Accordingly, the parameter(s) in the dedicated backup configuration may be related to the second CE mode. For example, in an embodiment where the first CE mode is CE mode A, the dedicated backup configuration may include one or more parameters related to CE mode B, including, for example, R-max, G factor (which may be It is used to define a USS), a downlink control information (DCI) format indicating a format of a PDCCH, and the like.

In some embodiments, a dedicated fallback configuration may be associated with one or more CE levels of the second CE mode. For example, a dedicated fallback configuration may include multiple parameter sets. Each parameter set is associated with one of the CE levels. In embodiments where the second CE mode is CE mode B, the dedicated fallback configuration may include two parameter sets for CE level 2 and CE level 3, respectively. In some other embodiments, there may be no such division of parameters in the dedicated backup configuration. The dedicated fallback configuration only includes parameter sets for the second CE mode.

In some embodiments, the terminal device 210 may be configured with one or more common backup configurations related to the second CE mode in addition to the dedicated backup configurations. Once the terminal device 210 initiates an RA attempt in the second CE mode, a common fallback configuration may be used, which will be discussed in detail in the following paragraphs.

End device 210 may determine whether to enable a dedicated fallback configuration by taking into account any suitable factors. In some embodiments, if some RA attempts in the first CE mode (referred to as the first set of RA attempts) have failed, the terminal device 210 may initiate additional RA attempts in the second CE mode (referred to as the first set of RA attempts). Two sets of RA attempts). After initiating the second set of RA attempts, the terminal device 210 may determine that the dedicated fallback configuration is enabled.

As another example, in an embodiment where the dedicated fallback configuration includes a parameter set for a CE level associated with a second CE mode, once a second set of RA attempts is initiated with that CE level, the terminal device 210 may determine the The parameter set corresponding to the selected CE level is enabled.

Other events can also trigger the enabling of dedicated fallback configurations. For example, during handover of the terminal device 210 from the network device 220 to another network device (not shown), it may be determined that the dedicated backup configuration is enabled. As another example, if the measured or reported RSRP level is below a threshold, the terminal device 210 may determine activation of a dedicated fallback configuration.

The enabling of a dedicated fallback configuration may also be triggered based on UE mobility. For example, if the terminal device 210 moves to an area in poor coverage of the network device 220, the terminal device 210 may determine that a dedicated fallback configuration should be enabled. Additionally or alternatively, the terminal device 210 may determine activation of the dedicated backup configuration based on cell deployment. For example, in cells in poor coverage, the terminal device 210 may determine activation of a dedicated backup configuration.

In some embodiments, an associated timer may be configured for a dedicated backup configuration. The terminal device 210 may obtain together from the network device 220 a dedicated backup configuration and an associated timer. In this case, the terminal device 210 may determine whether to enable the dedicated backup configuration based on a timer. If the timer expires, the terminal device 210 may determine that the dedicated backup configuration is disabled. In this way, the real-time performance of the configuration can be further ensured, so the success probability of the RA process can be further improved.

In block 315, after determining that the dedicated fallback configuration is enabled, the terminal device 210 detects the message from the network device 220 using the dedicated fallback configuration. The message may include any suitable message during the RA procedure. In some embodiments, the message may include an uplink grant from network device 220 .

In some embodiments, a dedicated fallback configuration may be used to detect messages after Msg3 has been successfully transmitted. For example, after the successful transmission or retransmission of Msg3 in the second CE mode, the terminal device 210 may start to use/activate the dedicated backup configuration. The terminal device 210 may then use the dedicated fallback configuration to detect the UL grant from the network device 220 . During the retransmission of Msg3, the terminal device 210 can still monitor the CSS for the MPDCCH scrambled with a temporary C-RNTI eg specified by the second CE mode and broadcast by the network device 220 . In these embodiments, the terminal device 210 may use the common configuration specified by the second CE mode before the successful transmission or retransmission of Msg3.

In embodiments where the dedicated fallback configuration is associated with the second CE mode and the terminal device 210 initiates the second set of RA attempts in the second CE mode, the dedicated fallback configuration may be triggered after initiation of the second set of RA attempts. For example, the terminal device 210 may switch to the second CE mode anonymously or implicitly. In some embodiments, the terminal device 210 may use the public configuration for the second CE mode before the Msg3 transmission or retransmission is successful, and use the dedicated backup configuration for further communication. Alternatively, in an embodiment where a common fallback configuration is also configured, the terminal device 210 may use the common fallback configuration after initiation of the second RA attempt.

In some embodiments, end device 210 may disable the dedicated fallback configuration based on the indication to disable the dedicated fallback configuration. The indication may include an indication from the network device 220, such as an indication for CE mode configuration or reconfiguration. For example, in the case that the terminal device 210 is configured with CE mode A, if the terminal device 210 receives an instruction to reconfigure CE mode B from the network device 220, the terminal device 210 may disable the dedicated backup configuration and start using the already configured Configure parameters related to CE mode-B. As another example, if the network device 220 reconfigures some CE Mode-A parameters to the terminal device 210, the terminal device 210 may also disable the dedicated fallback configuration.

In embodiments where the dedicated fallback configuration is associated with a timer, the indication to disable the dedicated fallback configuration may be an indication that the associated timer has expired. The end device 210 may disable the dedicated backup configuration after expiration of the timer.

In some embodiments, end device 210 may continue to use the dedicated fallback configuration in response to an indication of CE mode configuration or reconfiguration. For example, in an embodiment where a dedicated fallback configuration is associated with the second CE mode, if the network device 220 instructs the end device 210 to switch to the second CE mode, the end device 210 can use the public configuration for the second CE mode while Continue to use the dedicated fallback configuration.

In some embodiments, the terminal device 210 may automatically trigger radio link failure and re-establishment after failure of the RA procedure in the first CE mode. In this case, the first CE mode configuration may be refreshed before the terminal device 210 accesses the re-established cell.

In some embodiments, an apparatus capable of executing the method 300 (for example, the terminal device 210 ) may include components for executing corresponding steps of the method 300 . The component may be implemented in any suitable form. For example, the component may be implemented in circuitry or a software module.

In some embodiments, the apparatus comprises: means for initiating a random access procedure in a second CE mode different from a configured first coverage enhancement (CE) mode; for determining a dedicated backup during the random access procedure means for whether the configuration is enabled; and means for detecting a message from the network device using the dedicated backup configuration in response to determining that the dedicated backup configuration is enabled.

In some embodiments, the means for initiating comprises means for initiating a second set of random access attempts in the second CE mode in response to the first set of random access attempts in the first CE mode having failed.

In some embodiments, a dedicated fallback configuration is associated with the second CE mode. The means for determining includes means for determining that the dedicated backup configuration is enabled in response to initiation of the second set of random access attempts.

In some embodiments, the second CE mode is associated with a CE level, and the dedicated fallback configuration includes a parameter set for that CE level. The means for initiating a second set of random access attempts includes means for initiating a second set of random access attempts at the CE level. The means for determining includes means for determining that the parameter set is enabled in response to initiating a second set of random access attempts at the CE level.

In some embodiments, the apparatus further comprises means for continuing to use the dedicated fallback configuration for further communication with the network device in response to receiving the indication to switch the first CE mode to the second CE mode.

In some embodiments, a dedicated backup configuration is associated with a timer. The means for determining includes means for determining that the dedicated fallback configuration is disabled in response to expiration of the timer.

In some embodiments, the message includes an uplink grant from the network device. The means for detecting comprises means for detecting an uplink grant from a network device in response to a successful transmission of message 3 by using a dedicated fallback configuration.

In some embodiments, the apparatus further comprises means for receiving a dedicated backup configuration in radio resource control (RRC) signaling from the network device before initiating the random access procedure.

In some embodiments, the apparatus further includes means for disabling the dedicated fallback configuration in response to the indication to disable the dedicated fallback configuration.

FIG. 4 is a simplified block diagram of an apparatus 400 suitable for implementing embodiments of the present disclosure. The device 400 may be implemented at the terminal device 210 as shown in FIG. 2 , or at least partially implemented as a part thereof.

As shown, the device 400 includes a processor 410 , a memory 420 coupled to the processor 410 , a communication module 440 coupled to the processor 410 , and a communication interface (not shown) coupled to the communication module 440 . The memory 410 stores at least a program 430 . The communication module 440 is used for two-way communication. A communication interface may represent any interface required to communicate with a network element, such as a Uu interface for communication between an eNB and a UE.

Program 430 is assumed to include program instructions which, when executed by associated processor 410 , enable device 400 to operate in accordance with embodiments of the present disclosure, as discussed herein with reference to FIGS. 2-3 . The embodiments herein may be implemented by: computer software executable by the processor 410 of the device 400, or hardware, or a combination of software and hardware. The processor 410 may be configured to implement various embodiments of the present disclosure.

Memory 410 may be of any type suitable for a local technical network and may be implemented using any suitable data storage technology, such as non-transitory computer-readable storage media, semiconductor-based memory devices, magnetic memory devices, as non-limiting examples. Devices and systems, optical storage devices and systems, fixed and removable storage. Although only one memory 410 is shown in device 400 , there may be several physically distinct memory modules in device 400 . Processor 410 may be of any type suitable for a local technical network, and may include, as non-limiting examples, one or more of the following: a general purpose computer, a special purpose computer, a microprocessor, a digital signal processor (DSP), and A processor based on a multi-core processor architecture. Device 400 may have multiple processors, such as application specific integrated circuit chips, that are time slaved to a clock that is synchronized with the main processor.

In general, the 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. Although various aspects of the embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other graphical representation, it should be understood that, by way of non-limiting example, the blocks, devices, systems, techniques, or methods described herein Implementation may be by way of non-limiting examples: hardware, software, firmware, special purpose circuits or logic, general purpose hardware or a controller or other computing device, 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, which are executed in a device on a target real or virtual processor to perform the The method 300 described. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or divided among the program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed on local or distributed devices. In a distributed device, program modules may be located in both local and remote storage media.

Program code for carrying out the 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, a special-purpose computer, or other programmable data processing apparatus, so that the program codes, when executed by the processor or controller, make the flow charts and/or block diagrams specified The function/operation is implemented. The program code may execute entirely on the 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, computer program codes or related data may be carried by any suitable carrier, so that a device, apparatus or processor can perform the above various processes and operations. Examples of carriers include signals, computer readable media.

The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include, but is 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 computer readable storage media would include: an electrical connection with one or more wires, a portable computer floppy disk, a hard disk, random access memory (RAM), read only memory (ROM), erasable programmable Read memory (EPROM or flash memory), optical fiber, portable compact disc read only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination of the foregoing.

In addition, 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 some cases, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details have been contained in the above discussion, these should not be construed as limitations on the scope of the disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of single separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination.

Although the disclosure has been described in language specific to structural features and/or methodological acts, it is to be understood that the 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 (19)

1. A method of communication, comprising:

at a terminal device configured with a first Coverage Enhancement (CE) mode:

initiating a random access procedure in a second CE mode different from the first CE mode; and

during the random access procedure:

determining whether dedicated backup configuration is enabled

In response to determining that the dedicated backup configuration is enabled, a message from a network device is detected by using the dedicated backup configuration.

2. The method of claim 1, wherein initiating the random access procedure comprises:

a second set of random access attempts is initiated in the second CE mode in response to a first set of random access attempts in the first CE mode having failed.

3. The method of claim 2, wherein the dedicated backup configuration is associated with the second CE mode, and determining whether the dedicated backup configuration is enabled comprises:

in response to the initiation of the second set of random access attempts, it is determined that the dedicated backup configuration is enabled.

4. The method of claim 3, wherein the second CE mode is associated with a CE level and the dedicated back-up configuration includes a set of parameters for the CE level,

wherein initiating the second set of random access attempts comprises initiating the second set of random access attempts at the CE level, and

wherein determining that the dedicated backup configuration is enabled comprises: in response to initiating the second set of random access attempts at the CE level, determining that the set of parameters is enabled.

5. The method of any one of claims 1 to 4, further comprising:

in response to receiving an indication to switch the first CE mode to the second CE mode, continuing to use the dedicated backup configuration for further communication with the network device.

6. The method of any of claims 1-4, wherein the dedicated backup configuration is associated with a timer, and determining whether the dedicated backup configuration is enabled comprises:

in response to expiration of the timer, it is determined that the dedicated backup configuration is disabled.

7. The method of any of claims 1-4, wherein the message includes an uplink grant from the network device, and detecting the message from the network device includes:

the uplink grant from the network device is detected by using the dedicated backup configuration in response to successful transmission of message 3.

8. The method of any one of claims 1 to 4, further comprising:

the dedicated back-up configuration is received in Radio Resource Control (RRC) signaling from the network device prior to the initiation of the random access procedure.

9. The method of any one of claims 1 to 4, further comprising:

the dedicated backup configuration is disabled in response to an indication to disable the dedicated backup configuration.

10. An apparatus for communication, comprising:

at least one processor; and

at least one memory including computer program code;

the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to:

initiating a random access procedure in a second Coverage Enhancement (CE) mode different from the configured first CE mode; and

during the random access procedure:

determining whether dedicated backup configuration is enabled

In response to determining that the dedicated backup configuration is enabled, a message from a network device is detected by using the dedicated backup configuration.

11. The apparatus of claim 10, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to:

a second random access attempt is initiated in the second CE mode in response to a first random access attempt in the first CE mode having failed.

12. The apparatus of claim 11, wherein the dedicated backup configuration is associated with the second CE mode, and the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to:

in response to the initiation of the second random access attempt, it is determined that the dedicated backup configuration is enabled.

13. The apparatus of claim 12, wherein the second CE mode is associated with a CE level, and the dedicated backup configuration comprises a set of parameters for the CE level; and is also provided with

Wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to:

initiating a second random access attempt at said CE level

In response to initiating the second random access attempt at the CE level, determining that the parameter set is enabled.

14. The apparatus of any of claims 10 to 13, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to:

in response to receiving an indication to switch the first CE mode to the second CE mode, continuing to use the dedicated backup configuration for further communication with the network device.

15. The apparatus of any of claims 10 to 13, wherein the dedicated backup configuration is associated with a timer, and the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to:

in response to expiration of the timer, it is determined that the dedicated backup configuration is disabled.

16. The apparatus according to any of claims 10 to 13, wherein the message comprises an uplink grant from the network apparatus, and the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to:

the uplink grant from the network device is detected by using the dedicated backup configuration in response to successful transmission of message 3.

17. The apparatus of any of claims 10 to 13, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to:

the dedicated back-up configuration is received in Radio Resource Control (RRC) signaling from the network device prior to the random access procedure.

18. The apparatus of any of claims 10 to 13, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the apparatus to:

the dedicated backup configuration is disabled in response to an indication to disable the dedicated backup configuration.

19. A computer readable storage medium having stored thereon a computer program which, when executed by a processor, causes the processor to perform the method according to any of claims 1 to 9.

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