HK1220569B - Methods and devices for random access - Google Patents

Description

Method and apparatus for random access

Technical Field

The present disclosure relates generally to wireless communications, and more particularly to methods and apparatus for random access.

Background Art

With the development of Long Term Evolution (LTE) or Long Term Evolution-Advanced (LTE-A), a new feature called dynamic time division duplexing (TDD) is proposed.

For a communication device capable of operating in dynamic TDD mode, such as a user equipment, it may be assigned more than one TDD configuration. This may cause problems in some communication situations when a communication party (e.g., a user equipment or a base station) determines which TDD configuration the other communication party (e.g., a base station or a user equipment) is currently using.

Summary of the Invention

One or more methods and apparatuses according to the present disclosure aim to provide a communication solution for a communication device that can operate in a dynamic TDD scenario.

According to one aspect of the present disclosure, a method for operating a communications device is provided. According to one embodiment of the present disclosure, the method includes: sending a first message including a random access preamble to a network device according to a TDD configuration in a system information block (SIB); and receiving a second message including a random access response from a network node device using the random access preamble according to the TDD configuration in the SIB.

According to one aspect of the present disclosure, a method for operating a network node device is provided. According to one embodiment of the present disclosure, the method includes: receiving a first message including a random access preamble from a communication device according to a TDD configuration in a SIB; and directing the communication device to send a second message including a random access response using the random access preamble according to the TDD configuration in the SIB.

According to one aspect of the present disclosure, a communication device is provided. According to one embodiment of the present disclosure, the communication device includes: a transmitting unit configured to transmit a first message including a random access preamble to a network node device according to a time division duplex (TDD) configuration in a SIB; and a receiving unit configured to receive a second message including a random access response from the network node device using the random access preamble according to the TDD configuration in the SIB.

According to one aspect of the present disclosure, a network node device is provided. According to one embodiment of the present disclosure, the network node device includes: a receiving unit configured to receive a first message including a random access preamble from a communication device according to a TDD configuration in a SIB; and a sending unit configured to send a second message including a random access response to the communication device using the random access preamble according to the TDD configuration in the SIB.

According to one aspect of the present disclosure, a method for operating a communications device is provided. According to one embodiment of the present disclosure, the method includes: determining whether explicit signaling indicating a TDD configuration is received; selecting a random access synchronization code based on the determination result; sending a first message for a random access procedure including a random access preamble to a network node device based on the TDD configuration in a SIB; and performing subsequent message transmission for the random access procedure based on the TDD configuration determined based on the determination result. The communications device may be in an out-of-sync state.

According to one embodiment of the present disclosure, in a contention-based random access procedure, the step of selecting a random access preamble may include: in response to determining that explicit signaling is received, selecting a random access preamble belonging to a predefined subset of available random access preambles in a cell; and in response to determining that explicit signaling is not received, selecting a random access preamble that does not belong to the predefined subset of available random access preambles in the cell.

According to one embodiment of the present invention, the step of performing subsequent message reception and transmission for a random access procedure may include: in response to determining that explicit signaling is received, performing subsequent message reception and transmission for the random access procedure according to the TDD configuration indicated by the explicit signaling; and in response to determining that no explicit signaling is received, performing subsequent message reception and transmission for the random access procedure according to the TDD configuration in the system information block.

According to one embodiment of the present invention, in a contention-free random access procedure, explicit signaling may be configured to be transmitted to a communication device in the same message as a random access preamble assigned to the communication device. In response to determining that the explicit signaling is received, selecting the random access preamble may include selecting the random access preamble assigned to the communication device, and performing subsequent messaging for the random access procedure may include performing subsequent messaging for the random access procedure according to the TDD configuration indicated by the explicit signaling.

According to one embodiment of the present invention, the communication device may be a user equipment.

According to one embodiment of the present invention, the user equipment may be in an out-of-sync state.

According to another aspect of the present disclosure, a method for operating a network node device is provided. According to one embodiment of the present invention, the method includes: sending explicit signaling indicating a TDD configuration to a communication device; receiving a first message for a random access procedure including a random access preamble from the communication device according to the TDD configuration in a SIB; determining whether the communication device has received the explicit signaling based on the random access preamble; and performing subsequent message transmission and reception for the random access procedure according to the TDD configuration determined based on the determination result.

According to one embodiment of the present disclosure, in a contention-based random access process, the step of determining whether a communication device has received explicit signaling based on a random access preamble may include: determining that the communication device has received explicit signaling if the random access preamble belongs to a predefined subset of available random access preambles in a cell; and determining that the communication device has not received explicit signaling if the random access preamble does not belong to a predefined subset of available random access preambles in the cell.

According to one embodiment of the present disclosure, the step of performing subsequent message reception and transmission for a random access procedure may include: in response to determining that the communication device receives explicit signaling, performing subsequent message reception and transmission for the random access procedure according to the TDD configuration indicated by the explicit signaling; and in response to determining that the communication device does not receive explicit signaling, performing subsequent message reception and transmission for the random access procedure according to the TDD configuration in the system information block.

According to one embodiment of the present disclosure, in a contention-free random access procedure, explicit signaling may be configured to be transmitted to a communication device in a message along with a random access preamble assigned to the communication device. Determining whether the communication device has received the explicit signaling based on the random access preamble may include determining that the communication device has received the explicit signaling if the random access preamble is a random access preamble assigned to the communication device. Performing subsequent messaging for the random access procedure may include, in response to determining that the communication device has received the explicit signaling, performing subsequent messaging for the random access procedure according to a TDD configuration indicated by the explicit signaling.

According to one embodiment of the present disclosure, the network node device may be a base station.

According to one embodiment of the present disclosure, the method may be used for random access.

According to one aspect of the present disclosure, a communication device is provided. According to one embodiment of the present disclosure, the communication device may include: a receiving unit configured to receive a message from a network node device; a determining unit configured to determine whether the receiving unit has received explicit signaling indicating a TDD configuration; a selecting unit configured to select a random access preamble based on the determination result; and a sending unit configured to send a first message for a random access procedure including a random access preamble to the network node device based on the TDD configuration in the SIB. The sending unit and the receiving unit may be configured to perform subsequent message transmission and reception for the random access procedure based on the TDD configuration determined based on the determination result.

According to one embodiment of the present disclosure, in a contention-based random access process, the selection unit may be configured to: in response to the determination unit determining that the receiving unit has received explicit signaling, select a random access preamble belonging to a predefined subset of available random access preambles in the cell; and in response to the determination unit determining that the receiving unit has not received explicit signaling, select a random access preamble that does not belong to the predefined subset of available random access preambles in the cell.

According to one embodiment of the present disclosure, the sending unit and the receiving unit may be configured to: in response to the determining unit determining that the receiving unit has received explicit signaling, perform subsequent message reception and sending for the random access procedure according to the TDD configuration indicated by the explicit signaling; and in response to the determining unit determining that the receiving unit has not received explicit signaling, perform subsequent message reception and sending for the random access procedure according to the TDD configuration in the system information block.

According to one embodiment of the present disclosure, in a contention-free random access procedure, explicit signaling may be configured to be transmitted to a communication device in the same message as a random access preamble assigned to the communication device. In response to the determination unit determining that the receiving unit has received the explicit signaling, the selection unit may be configured to select the random access preamble assigned to the communication device, and the sending unit and the receiving unit may be configured to perform subsequent message reception and transmission for the random access procedure according to the TDD configuration indicated by the explicit signaling.

According to one embodiment of the present disclosure, the communication device may be a user equipment.

According to one embodiment of the present disclosure, the user equipment may be in an out-of-sync state.

According to another aspect of the present disclosure, a network node device is provided. According to one embodiment of the present disclosure, the network node device includes: a transmitting unit configured to transmit explicit signaling indicating a TDD configuration to a communication device; a receiving unit configured to receive a first message for a random access procedure including a random access preamble from the communication device based on the TDD configuration in a SIB; and a determining unit configured to determine, based on the random access preamble, whether the out-of-sync communication device has received the explicit signaling. The transmitting unit and the receiving unit are configured to perform subsequent message transmission and reception for the random access procedure based on the TDD configuration determined based on the determination result.

According to one embodiment of the present disclosure, in a contention-based random access process, the determination unit may be configured to: determine that the communication device has received explicit signaling if the random access preamble belongs to a predefined subset of available random access preambles in the cell; and determine that the communication device has not received explicit signaling if the random access preamble does not belong to a predefined subset of available random access preambles in the cell.

According to one embodiment of the present disclosure, the sending unit and the receiving unit may be configured to: in response to the determining unit determining that the communication device has received explicit signaling, perform subsequent message reception and sending for the random access procedure according to the TDD configuration indicated by the explicit signaling; and in response to the determining unit determining that the communication device has not received explicit signaling, perform subsequent message reception and sending for the random access procedure according to the TDD configuration in the system information block.

According to one embodiment of the present disclosure, in a contention-free random access procedure, explicit signaling may be configured to be transmitted to a communication device in a message along with a random access preamble assigned to the communication device. A determining unit may be configured to determine that the communication device has received the explicit signaling if the random access preamble is the random access preamble assigned to the communication device. The transmitting unit and the receiving unit may be configured to, in response to determining that the communication device has received the explicit signaling, perform subsequent message transmission and reception for the random access procedure according to the TDD configuration indicated by the explicit signaling.

According to one embodiment of the present disclosure, the network node device may be a base station.

According to one aspect of the present disclosure, a communication device is provided. According to one embodiment of the present disclosure, the communication device includes: a processing device adapted to send a first message including a random access preamble to a network node device according to a time division duplex (TDD) configuration in a system information block; and receive a second message including a random access response from the network node device using the random access preamble according to the TDD configuration in the system information block. According to one embodiment of the present disclosure, the processing device may include a processor and a memory, and the memory may contain instructions executable by the processor.

According to another aspect of the present disclosure, a network node device is provided. According to one embodiment of the present disclosure, the network node device includes: a processing device configured to receive a first message including a random access preamble from a communication device according to a TDD configuration in a system information block; and direct the communication device to send a second message including a random access response using the random access preamble according to the TDD configuration in the system information block. According to one embodiment of the present disclosure, the processing device may include a processor and a memory, and the memory may include instructions executable by the processor.

According to another aspect of the present disclosure, a communications device is provided. According to one embodiment of the present disclosure, the communications device includes: a processing device adapted to determine whether explicit signaling indicating a TDD configuration is received; select a random access preamble based on the determination result; send a first message for a random access procedure including the random access preamble to a network node device based on the TDD configuration in a system information block; and perform subsequent message transmission and reception for the random access procedure based on the TDD configuration determined based on the determination result. According to one embodiment of the present disclosure, the processing device may include a processor and a memory, and the memory may contain instructions executable by the processor.

According to another aspect of the present disclosure, a network node device is provided. According to one embodiment of the present disclosure, the network node device includes: a processing device adapted to send explicit signaling indicating a TDD configuration to a communication device; receive a first message for a random access procedure including a random access preamble from the communication device according to the TDD configuration broadcast in a system information block; determine whether the communication device has received the explicit signaling based on the random access preamble; and perform subsequent message transmission and reception for the random access procedure according to the TDD configuration determined based on a result of the determination. According to one embodiment of the present disclosure, the processing device may include a processor and a memory, and the memory may contain instructions executable by the processor.

According to another aspect of the present disclosure, a method for operating a network node device that serves a communication device via at least one secondary cell in carrier aggregation is provided. The method comprises: sending RRC signaling to the communication device according to a TDD configuration in a system information block to instruct the communication device to enable a mode capable of dynamic TDD; receiving an acknowledgment from the communication device that the communication device received the RRC signaling according to the TDD configuration in the system information block; and communicating with the communication device via the at least one secondary cell according to the mode capable of dynamic TDD.

According to another aspect of the present disclosure, a method for operating a communication device is provided, wherein the communication device is served by a network node device via at least one secondary cell in carrier aggregation. The method includes: receiving RRC signaling from the network node device according to a TDD configuration in a system information block, wherein the RRC signaling instructs the communication device to enable a mode capable of dynamic TDD; sending an acknowledgment indication to the network node device according to the TDD configuration in the system information block to instruct the communication device to receive the RRC signaling; determining whether the network node device has received the acknowledgment indication; in response to determining that the network node device has received the acknowledgment indication, communicating with the network node device via the at least one secondary cell according to the mode capable of dynamic TDD; and in response to determining that the network node device has not received the acknowledgment indication, communicating with the network node device via the at least one secondary cell according to the TDD configuration in the system information block.

According to another aspect of the present disclosure, a network node device is provided for serving a communication device via at least one secondary cell in carrier aggregation. The network node device includes: a transmitting unit configured to transmit RRC signaling to the communication device according to a TDD configuration in a system information block to instruct the communication device to enable a dynamic TDD-capable mode; a receiving unit configured to receive an acknowledgment from the communication device that the communication device received the RRC signaling according to the TDD configuration in the system information block; and a control unit configured to control the transmitting unit and the receiving unit to communicate with the communication device via the at least one secondary cell according to the dynamic TDD-capable mode.

According to another aspect of the present disclosure, a communication device served by a network node device through at least one secondary cell in carrier aggregation is provided. The communication device includes: a receiving unit configured to receive RRC signaling from the network node device according to a TDD configuration in a system information block, wherein the RRC signaling instructs the communication device to enable a mode capable of dynamic TDD; a sending unit configured to send a confirmation indication to the network node device according to the TDD configuration in the system information block to instruct the communication device to receive the RRC signaling; a determining unit configured to determine whether the network node device has received the confirmation indication; a control unit configured to: in response to determining that the network node device has received the confirmation indication, control the receiving unit and the sending unit to communicate with the network node device through at least one secondary cell according to the mode capable of dynamic TDD; and in response to determining that the network node device has not received the confirmation indication, control the receiving unit and the sending unit to communicate with the network node device through at least one secondary cell according to the TDD configuration in the system information block.

According to another aspect of the present disclosure, a network node device is provided. According to one embodiment of the present disclosure, the network node device includes: a processing device adapted to send RRC signaling to a communication device according to a TDD configuration in a system information block to instruct the communication device to enable a mode capable of dynamic TDD; receive an acknowledgment indication from the communication device that the communication device received the RRC signaling according to the TDD configuration in the system information block; and communicate with the communication device via at least one secondary cell according to the mode capable of dynamic TDD. According to one embodiment of the present disclosure, the processing device may include a processor and a memory, and the memory may contain instructions executable by the processor.

According to another aspect of the present disclosure, a communication device is provided. According to one embodiment of the present disclosure, the communication device includes: a processing device, adapted to receive RRC signaling from a network node device according to RRC signaling in a system information block, wherein the RRC signaling instructs the communication device to enable a mode capable of dynamic TDD; send an acknowledgment indication to the network node device according to the TDD configuration in the system information configuration block to indicate that the communication device has received the RRC signaling; determine whether the network node device has received the acknowledgment indication; in response to determining that the network node device has received the acknowledgment indication, communicate with the network node device through at least one secondary cell according to the mode capable of dynamic TDD; and in response to determining that the network node device has not received the acknowledgment indication, communicate with the network node device through at least one secondary cell according to the TDD configuration in the system information block. According to one embodiment of the present disclosure, the processing device may include a processor and a memory, and the memory may contain instructions executable by the processor.

According to one or more embodiments of the present disclosure, when a UE in an out-of-sync and/or link failure state initiates a random access process in a dynamic TDD scenario, the UE and the corresponding base station (e.g., an evolved Node B) may use a consistent TDD configuration in the message transmission and reception for the random access process, thereby significantly reducing the random access failure of such a UE in a dynamic TDD scenario.

BRIEF DESCRIPTION OF THE DRAWINGS

The inventive features which are considered as characteristic of the present invention are set forth in the appended claims. However, the present invention, its embodiments and other objects, features and advantages will be better understood by reading the following detailed description of exemplary embodiments with reference to the accompanying drawings, in which:

FIG1A is a diagram schematically illustrating a contention-free random access procedure;

FIG1B is a diagram schematically illustrating a contention-based random access procedure;

FIG2 schematically illustrates an example flow chart of a method for operating a communication device according to one or more embodiments of the present disclosure;

FIG3 schematically illustrates an example flow chart for operating a network node device according to one or more embodiments of the present disclosure;

FIG4 is a block diagram schematically illustrating a communication device according to one or more embodiments of the present disclosure;

FIG5 is a block diagram schematically illustrating a network node device according to one or more embodiments of the present disclosure;

FIG6 schematically illustrates an example flow chart for operating a communication device according to one or more embodiments of the present disclosure;

FIG7 schematically illustrates an example flow chart of a method for operating a network node device according to one or more embodiments of the present disclosure;

FIG8 is a block diagram of a communication device according to one or more embodiments of the present disclosure;

FIG9 is a block diagram schematically illustrating a network node device according to one or more embodiments of the present disclosure;

FIG10 schematically illustrates an example flow chart of a method for operating a communication device according to one or more embodiments of the present disclosure;

FIG11 schematically illustrates an example flow chart of a method for operating a network node device according to one or more embodiments of the present disclosure;

FIG12 is a block diagram schematically illustrating a communication device according to one or more embodiments of the present disclosure;

FIG13 is a block diagram schematically illustrating a network node device according to one or more embodiments of the present disclosure.

DETAILED DESCRIPTION

Embodiments of the present disclosure will be described below with reference to the accompanying drawings. In the following description, many specific details are illustrated in order to more fully understand the present disclosure. However, it will be clear to those skilled in the art that the present invention may be implemented without these details. Additionally, it should be understood that the present invention is not limited to the specific embodiments as described herein. Quite the contrary, it can be considered that the combination of the following features and units implements and realizes the present invention regardless of whether they relate to different embodiments. For example, although it is described below in the context of an LTE or LTE-A type wireless communication system for illustrative purposes, those skilled in the art will recognize that one or more embodiments of the present disclosure may also be applicable to various other types of wireless communication systems. Therefore, the following aspects, features, embodiments and advantages are for illustrative purposes only and should not be understood as elements or limitations of the appended claims unless otherwise expressly specified in the claims.

According to the dynamic TDD technology, the TDD configuration of a cell can be dynamically changed according to the instantaneous traffic in the cell. TDD allows different asymmetries in the amount of resources allocated for uplink and downlink transmission respectively by means of different downlink/uplink configurations. Taking Long Term Evolution (LTE) as an example, there are seven different TDD configurations specified in Table 4.2-2 of the 3GPP standard 36.211 v8.4.0. If there is more downlink traffic in the cell, the TDD configuration can be configured to support a TDD configuration with heavier downlink traffic (also called a downlink heavier configuration); and if there is more uplink traffic in the cell, the TDD configuration can be configured to support a TDD configuration with heavier uplink traffic (also called an uplink heavier configuration). The dynamic TDD feature can be enabled, and the user equipment (UE) obtains two TDD configurations from a base station, such as an evolved Node B (eNodeB). One is the uplink heavier TDD configuration broadcast in the System Information Block (SIB), and the other is the downlink heavier TDD configuration notified to the UE via dedicated Radio Resource Control (RRC) signaling when the UE first attaches to the network. All possible TDD configurations that can be applied in communications between the UE and the eNodeB are determined by the uplink heavier TDD configuration broadcast in the SIB and the downlink heavier TDD configuration notified via dedicated RRC signaling. Each of those determined TDD configurations configures uplink subframes that belong to a subset of uplink subframes for the uplink heavier TDD configuration in the SIB and downlink subframes that belong to a subset of downlink subframes for the downlink heavier TDD configuration in the dedicated RRC signaling.

However, in dynamic TDD scenarios, multiple TDD configurations can be used between the UE and the eNodeB. Therefore, a UE that has been assigned more than one TDD configuration but is currently out of synchronization or experiencing a link failure can initiate a random access procedure using any of those TDD configurations. However, the eNodeB is unaware of which TDD configuration the UE actually uses when communicating the random access procedure. Inconsistent TDD configurations between the UE and eNodeB will cause the random access procedure to fail.

The term "out-of-sync" as used throughout this disclosure refers to a communication device state when uplink (UL) timing alignment is not maintained. For example, as defined in 3GPP TS 36.331 v12.0.0, the TimeAlignmentTimer information element is used to control the duration that a communication device considers its serving cell to be uplink time-aligned. Upon expiration of the timer, the communication device considers the uplink out-of-sync and requires a random access procedure to acquire uplink timing.

The term "link failure" mentioned in this disclosure also refers to a communication device status. If the downlink radio quality drops below a given threshold, the communication device will indicate a loss of synchronization to higher layers. If the communication device detects that the out-of-sync state persists for a certain period of time, a radio link failure (RLF) occurs, and the communication requires reestablishing the RRC connection via a random access procedure.

Therefore, there is a need to provide a communication solution that facilitates random access for out-of-sync and/or link failure communication devices that may operate in dynamic TDD scenarios, for example.

FIG1A is a diagram schematically illustrating a contention-free random access procedure in the related art.

In a contention-free random access procedure, eNodeB 120 transmits a message (MSG0) for random access preamble assignment to UE 110 via the Physical Downlink Control Channel (PDCCH). This message includes a random access preamble assigned to UE 110. In this example, UE 110 is already connected to the network but out of synchronization. UE 110 retrieves the random access preamble from the received MSG0 and transmits it to eNodeB 120 in a first message (MSG1) of a random access request. eNodeB 120 monitors a selected uplink channel to receive MSG1. Upon receiving MSG1, eNodeB 120 transmits a second message (MSG2) including a random access response to UE 110 via the Downlink Shared Channel (DL-SCH) to confirm the successful detection of the preamble. eNodeB 120 and UE 110 are thus aligned in the time domain.

FIG1B is a diagram schematically illustrating a contention-based random access procedure in the related art.

In a contention-based random access procedure, UE 110 initiates the random access procedure by sending a first message (MSG1) containing a random access preamble selected from all preambles available in the cell on a selected uplink channel. eNodeB 120 monitors the uplink channel to detect the preamble. eNodeB 120 then sends a second message (MSG2) containing a random access response to confirm the successful detection of the preamble. If UE 110 receives MSG2, UE 110 sends a third message (MSG3) containing an identifier specific to UE 110 to eNodeB 120. UE 110 then monitors the designated downlink channel for a response from eNodeB 120. eNodeB 120 attempts to resolve any contention and sends a fourth message (MSG4) containing a contention resolution to UE 110.

According to 3GPP specification TS 36.213 V11.4.0, the uplink timing requirements for the random access procedure are described as follows:

For the layer 1 random access procedure, the UE's uplink transmission timing after random access preamble transmission is as follows.

a. If a PDCCH (Physical Downlink Control Channel) associated with a Radio Access Radio Network Temporary Identifier (RA-RNTI) is detected in subframe n, and the corresponding DL-SCH transport block contains a response to the transmitted preamble sequence, then if the UE Delay field is set to zero, the UE shall transmit the UL-SCH transport block in the first subframe n+ _k1 , _k1 ≥ 6 according to the information in the response, where n+ _k1 is the first available UL subframe for PUSCH transmission. If the field is set to 1, the UE shall defer PUSCH transmission to the next available UL subframe after n+ _k1 .

b. If a random access response is received in subframe n and the corresponding DL-SCH transport block does not contain a response to the transmitted preamble, then the UE shall be ready to transmit a new preamble no later than in subframe n+5 if requested by higher layers.

c. If no random access response is received in subframe n, where subframe n is the last subframe of the random access response window, then the UE shall be ready to transmit a new preamble no later than subframe n+4 if requested by higher layers.

In case the random access procedure is initiated by a "PDCCH order" in subframe n (i.e. contention-free random access), the UE shall transmit a random access preamble in the first subframe n+ _k2 , _k2≥6 , where PRACH (Packet Random Access Channel) resources are available, if requested by higher layers.

Therefore, it can be seen that both MSG1 in contention-free random access and MSG3 in contention-based random access have strict timing requirements.

According to 3GPP specification TS 36.321 V11.2.0, the downlink timing requirements for the random access procedure are described as follows:

Once the random access preamble is transmitted and regardless of any measurement gaps that may occur, the UE shall monitor the PDCCH of the PCell (primary cell) for random access responses identified by the RA-RNTI defined below in the RA response window starting at the following subframe, which contains the end of the preamble transmission plus three subframes and has a length of ra-ResponseWindowSize subframes.

Therefore, it can be seen that receiving MSG2 also has timing requirements.

According to an example of the present disclosure, the transmission/reception of MSG1 follows the TDD configuration in the SIB, and the transmission/reception of MSG1 at eNodeB 120 and UE 110 can then be aligned. On the other hand, the transmission/reception of MSG2/3/4 may still be subject to uncertainty, as UE 110/eNodeB 120 may transmit/receive MSG2/3/4 according to any of the possible TDD configurations, which may not be known to its peer device, in a dynamic TDD scenario. Even if explicit signaling is used to inform UE 110 of which TDD configuration eNodeB 120 will use, eNodeB 120 still cannot know whether UE 110 initiating random access has detected the explicit signaling, as UE 110 may be in active time or in sleep time if it is out of synchronization.

Embodiments of the present disclosure are intended to eliminate such TDD configuration ambiguity at least in the random access procedure between a network node device, such as an eNodeB, and a communication device, such as a UE, that has been assigned more than one TDD configuration, so that the communication device/network node device can know which TDD configuration is used by its peer device in the random access messaging.

In the present disclosure, a communication device, also referred to as a mobile terminal, wireless terminal, and/or user equipment (UE), is enabled to wirelessly communicate with a network node in a wireless communication system, sometimes also referred to as a cellular radio system. Examples of a communication device include, but are not limited to, a mobile phone, a smartphone, a sensor device, a meter, a vehicle, a home appliance, a medical appliance, a media player, a camera, or any type of consumer electronic device, such as, but not limited to, a television, a radio, a lighting fixture, a tablet computer, a laptop, or a PC. A "terminal device/communication device" may be a portable, pocket-storable, handheld, computer-integrated, or vehicle-mounted mobile device capable of communicating voice and/or data via a wireless or wired connection.

Typically, a network node device may serve or cover one or several cells of a wireless communication system. That is, the network node device provides radio coverage in the cell and communicates with communication devices operating on radio frequencies within its range over an air interface. The network node devices in some wireless communication systems may also be referred to as "eNB," "eNodeB," "Node B," or "B-node" depending on the technology and terminology used. In the present disclosure, the network node device may also be referred to as a base station (BS). The network node device may be of different categories based on transmit power and thus also based on cell size, such as, for example, a macro eNodeB, a home eNodeB, or a pico base station or a relay node.

Solution 1

2-5 , various embodiments of Solution 1 of the present disclosure are described in detail.

FIG2 schematically illustrates an example flow chart of a method 200 for operating a communication device according to one or more embodiments of the present disclosure.

A communications device may be in an out-of-sync or link failure state, requiring it to initiate a random access procedure with a network node device, such as an eNodeB. The communications device may have been assigned more than one TDD configuration before initiating the random access procedure. Those previously assigned TDD configurations may include a TDD configuration in the SIB and at least one other TDD configuration notified by the eNodeB via dedicated radio resource control signaling.

As shown in FIG2 , in block S210, a communication device, such as UE 110 as shown in FIG1A and 1B , sends a first message (MSG1) including a random access preamble to a network node device, such as eNodeB 120 as shown in FIG1A and 1B , according to the TDD configuration in the SIB.

In block S220, the communication device receives a second message (MSG2) including a random access response from the network node device using a random access preamble according to the TDD configuration in the SIB. In the contention-free random access procedure, the communication device and the network node device can thus be aligned in the time domain in this block.

According to one or more embodiments regarding the contention-based random access procedure, the method 200 may further proceed with blocks S230 - S240 .

In block S230 , the communication device may send a third message ( MSG3 ) including an identifier specific to the communication device to the network node device according to the TDD configuration in the SIB.

In block S240 , the communication device may receive a fourth message ( MSG4 ) according to the TDD configuration in the SIB or the dynamic TDD configuration depending on whether the communication device and the base station switch to a dynamic TDD-enabled mode.

According to one embodiment of the present disclosure, as an option, the communication device may be switched to a dynamic TDD-capable mode to support multiple dynamic TDD configurations after sending MSG3 in block S230. During the switching process, the communication device may be configured to switch to a dynamic TDD-capable mode by RRC signaling received from a network node device. In this embodiment, the communication device may receive MSG4, including contention resolution, from the network node device in block S240 by monitoring downlink channels according to multiple dynamic TDD configurations. Specifically, the communication device will monitor all downlink channels allowed by the multiple dynamic TDD configurations to receive MSG4.

According to one embodiment of the present disclosure, as another option, the communication device may be switched to a dynamic TDD-capable mode to support multiple dynamic TDD configurations after the UE receives MSG4 in block S240. During the switching process, the communication device may be configured to switch to a dynamic TDD-capable mode by RRC signaling received from a network node device. In this embodiment, in block S240, the UE may be configured to receive MSG4 according to the TDD configuration in the SIB.

According to an embodiment of the present disclosure, each of the multiple dynamic TDD configurations may have uplink subframes belonging to a subset of the uplink subframes of the TDD configuration in the system information block and downlink subframes belonging to a subset of the downlink subframes of the TDD configuration that has been assigned to the communication device by the network node device and notified via dedicated resource control signaling.

FIG3 schematically illustrates an example flow chart of a method 300 for operating a network node device according to one or more embodiments of the present disclosure.

The network node device may be a base station, such as eNodeB 120 as shown in Figures 1A and 1B.

As shown in FIG3 , in block S310, a network node device receives a first message (MSG1) including a random access preamble from a communication device, such as UE 110 shown in FIG1A and FIG1B , according to the TDD configuration in the SIB. The communication device may be in an out-of-sync or link failure state, and therefore it needs to initiate a random access procedure with a network node device, such as an eNodeB. The network node device may have assigned more than one TDD configuration to the communication device before initiating the random access procedure. Those previously assigned TDD configurations may include the TDD configuration in the SIB and at least one other TDD configuration notified via dedicated radio resource control signaling.

In block S320, the network node device sends a second message (MSG2) including a random access response to the communication device using the pre-random access guidance according to the TDD configuration in the SIB. In the contention-free random access procedure, the network node device and the communication device can thus be aligned in the time domain in this block.

According to one or more embodiments of the present disclosure regarding contention-based random access procedures, the method 300 may further proceed with blocks S330 - S340 .

In block S330 , the network node device may receive a third message ( MSG3 ) including an identifier specific to the communication device from the communication device according to the TDD configuration in the SIB.

In block S340 , the network node device may send a fourth message ( MSG4 ) according to the TDD configuration in the SIB or the dynamic TDD configuration depending on whether the communication device and the network node device are switched to a dynamic TDD capable mode.

According to one embodiment of the present disclosure, as an option, the network node device may switch to a dynamic TDD-capable mode after receiving MSG3 in block S330 to support multiple dynamic TDD configurations. During the switching process, the network node device may also configure the communication device to switch to a dynamic TDD-capable mode, for example, via RRC signaling. In this embodiment, the network node device may send MSG4 including contention resolution to the communication device in block S340 according to one of the multiple dynamic TDD configurations.

According to one embodiment of the present disclosure, as another option, the network node device may be switched to a dynamic TDD-capable mode to support multiple dynamic TDD configurations after the base station sends the MSG in block S340. During the switching process, the network node device may also configure the communication device to switch to a dynamic TDD-capable mode, for example, via RRC signaling. In this embodiment, in block S340, the network node device may send MSG4 according to the TDD configuration in the SIB.

According to an embodiment of the present disclosure, each of the multiple dynamic TDD configurations may have uplink subframes belonging to a subset of the uplink subframes of the TDD configuration in the system information block and downlink subframes belonging to a subset of the downlink subframes of the TDD configuration that has been assigned to the communication device by the network node device and notified via dedicated resource control signaling.

FIG4 is a block diagram schematically illustrating a communication device 400 according to one or more embodiments of the present disclosure.

The communication device 400 may be currently in a state of out-of-sync or link failure and needs to initiate a random access procedure with a network node device, such as an eNodeB. The communication device may have been assigned more than one TDD configuration before initiating the random access procedure. Those previously assigned TDD configurations may include a TDD configuration in the SIB and at least one other TDD configuration notified by the eNodeB via dedicated radio resource control signaling.

As shown in FIG4 , a communication device 400, such as the communication device 110 shown in FIG1A and FIG1B , includes a transmitting unit 410 and a receiving unit 420 for communicating with a network node device, such as the eNodeB 120 shown in FIG1A and FIG1B . The transmitting unit 410 and the receiving unit 420 may include any appropriate hardware components for bidirectional wireless communication with the network node device. For example, the transmitting unit 410 and the receiving unit 420 may be implemented as an appropriate radio frequency transceiver (i.e., may be implemented as a single component or as separate transmitters and receivers) for bidirectional wireless communication with the network node device via one or more antennas (not shown in FIG4 ).

The communication device 400 also includes a processor 40, which includes one or more microprocessors or microcontrollers and other digital hardware, which may include a digital signal processor (DSP), dedicated digital logic, etc. The processor 40 can be configured to execute program code stored in a memory (not shown in FIG. 4 ), which may include one or more types of memory, such as read-only memory (ROM), random access memory, cache memory, flash memory devices, optical storage devices, etc. The program code stored in the memory includes, in several embodiments, program instructions for executing one or more telecommunication and/or data communication protocols and instructions for implementing one or more of the techniques described herein.

The sending unit 410 is configured to send a first message (MSG1) including a random access preamble to a network node device according to the TDD configuration in the SIB.

The receiving unit 420 is configured to receive a second message (MSG2) including a random access response from the network node device using a random access preamble according to the TDD configuration in the SIB. In the contention-free random access procedure, the UE 400 can thereby align with the network node device in the time domain by receiving the random access response.

According to one or more embodiments regarding the contention-based random access procedure, the sending unit 410 may be further configured to send a third message (MSG3) including an identifier specific to the communication device 400 to the network node device according to the TDD configuration in the SIB during the contention-based random access procedure.

According to one embodiment of the present disclosure, one functional aspect of the processor 40 may include a control unit 430 configured to switch the communication device to a dynamic TDD-capable mode to support multiple dynamic TDD configurations after the communication device 400 transmits MSG3. In this embodiment, the receiving unit 420 may be configured to receive a fourth message (MSG4) including contention resolution from the network node device by monitoring the downlink channel according to the multiple dynamic TDD configurations.

According to another embodiment of the present disclosure, the receiving unit 420 may be further configured to receive a fourth message (MSG4) including contention resolution from the network node device according to the TDD configuration in the SIB. In this embodiment, the control unit 430 may be configured to switch the communication device to a dynamic TDD-capable mode to support multiple dynamic TDD configurations after receiving MSG4.

According to an embodiment of the present disclosure, each of the multiple dynamic TDD configurations may have uplink subframes belonging to a subset of the uplink subframes of the TDD configuration in the system information block and downlink subframes belonging to a subset of the downlink subframes of the TDD configuration that has been assigned to the communication device by the network node device and notified via dedicated resource control signaling.

FIG5 is a block diagram schematically illustrating a network node device according to one or more embodiments of the present disclosure.

As shown in FIG5 , a network node device, such as the eNodeB 120 shown in FIG1A and FIG1B , includes a receiving unit 510 and a transmitting unit 520 for communicating with a communication device, such as the UE 110 shown in FIG1A and FIG1B . A communication device may lose synchronization or experience a link failure, necessitating a random access procedure with the network node device, such as the eNodeB. The network node device 500 may have assigned more than one TDD configuration to the communication device before initiating the random access procedure. Those previously assigned TDD configurations may include a TDD configuration in the SIB and at least one other TDD configuration signaled via dedicated radio resource control signaling. The receiving unit 510 and the transmitting unit 520 may include any suitable hardware components for bidirectional wireless communication with one or more communication devices. For example, the receiving unit 510 and the transmitting unit 520 may be implemented as suitable radio frequency transceivers (i.e., may be implemented as a single component or as separate transmitters and receivers) for bidirectional wireless communication with one or more communication devices via one or more antennas (not shown in FIG5 ).

The network node device 500 also includes a processor 50, which includes one or more microprocessors or microcontrollers and other digital hardware, which may include a digital signal processor (DSP), dedicated digital logic, etc. The processor 50 can be configured to execute program code stored in a memory (not shown in Figure 5), which may include one or more types of memory, such as read-only memory (ROM), random access memory, cache memory, flash memory device, optical storage device, etc. The program code stored in the memory includes program instructions for executing one or more remote communication and/or data communication protocols and instructions for implementing one or more of the technologies described herein in several embodiments.

The receiving unit 510 is configured to receive a first message (MSG1) including a random access preamble from a communication device according to the TDD configuration in the SIB.

The transmitting unit 520 is configured to send a second message (MSG2) including a random access response to the communication device using the pre-random access guidance according to the TDD configuration in the SIB. In the contention-free random access procedure, the network node device 500 can thereby align with the communication device in the time domain when the UE receives the random access response.

According to one or more embodiments regarding the contention-based random access procedure, the receiving unit 510 may also be configured in the contention-based random access procedure to receive a third message (MSG3) including a communication device-specific identifier from the communication device according to the TDD configuration in the SIB.

According to one embodiment of the present disclosure, one functional aspect of the processor 50 may include a control unit 530 configured to switch the network node device to a dynamic TDD-capable mode to support multiple dynamic TDD configurations after the network node device 500 receives MSG3. In this embodiment, the transmitting unit 520 may also be configured to transmit a fourth message (MSG4) including contention resolution to the communication device according to one of the multiple dynamic TDD configurations.

According to another embodiment of the present disclosure, the transmitting unit 520 may be further configured to transmit a fourth message (MSG4) including contention resolution to the communication device according to the TDD configuration in the SIB. The control unit 530 may be configured to switch the network node device 500 to a dynamic TDD-capable mode to support multiple dynamic TDD configurations after transmitting MSG4.

According to an embodiment of the present disclosure, each of the multiple dynamic TDD configurations may have uplink subframes belonging to a subset of the uplink subframes of the TDD configuration in the system information block and downlink subframes belonging to a subset of the downlink subframes of the TDD configuration that has been assigned to the communication device by the network node device and notified via dedicated resource control signaling.

In the general case of Solution 1, all messages received on the common search space can follow the timing given by the TDD configuration in the SIB. As an example, during the process of switching the communication device to a mode capable of dynamic TDD as shown in Figures 2 and 3, the communication device can be configured by RRC signaling from the network node device. The communication device is scheduled for uplink traffic on the common search space and follows the TDD configuration in the SIB until the network node device has received an acknowledgment message (such as RRC reconfiguration complete) from the communication device to indicate that it is switching to a mode capable of dynamic TDD. In one embodiment, the feedback timing of the network node device for downlink scheduling on the common search space (i.e., at least for downlink subframes or special subframes according to the TDD configuration in the SIB) also follows the TDD configuration in the SIB. After the RRC reconfiguration message that can, for example, instruct the network node device to switch to a mode capable of dynamic TDD, the network node device can follow the timing associated with the dynamic TDD configuration in the scheduling received on the communication device-specific search space. In another implementation, the RNTI or DCI format used to scramble downlink control information (DCI) may also be used to indicate the TDD configuration to be used for UL transmission.

Those skilled in the art will recognize that various embodiments of Solution 1 according to the present disclosure can also be implemented in a handover scenario in which a communication device is handed over from a source cell served by a source network node device to a cell served by a target network node device. During handover preparation, the target network node device may inform the source network node device of the TDD configuration in the SIB of the target cell via RRC signaling MobilityControlInfo. The TDD configuration in the SIB of the target cell may then be signaled by the source network node device to the communication device during handover execution. Based on the received TDD configuration in the SIB of the target cell, the communication device may be operable to perform a random access procedure in the target cell as described above in conjunction with FIG. 2 .

Note that the configuration in the SIB here is used as a general term for the configuration to be applied in the cell for legacy users, and this information can be obtained, for example, by reading the SIB (if present) or through other signaling such as RadioResourceConfigCommonSCell or other RRC signaling in a handover or carrier aggregation scenario.

According to one or more embodiments of Solution 1 of the present disclosure, when a communication device initiates a random access procedure in a dynamic TDD scenario, the communication device and a corresponding network node device, such as an eNodeB, can use a consistent TDD configuration in the SIB to perform messaging for the random access procedure. This eliminates TDD configuration uncertainty between the network node device and the communication device. These approaches significantly reduce random access failures in dynamic TDD scenarios for communication devices experiencing desynchronization or link failures.

Solution 2

In various embodiments of Solution 2, explicit signaling can be used to carry the TDD configuration that the eNodeB intends the communication device to use. This information can be used by a communication device that has lost synchronization when initiating a random access procedure. Since the communication device that has lost synchronization is still in connected mode, it can be in either active time or sleep time when the explicit signaling is transmitted from the eNodeB. Therefore, a communication device in active time can detect the explicit signaling and thus know the TDD configuration that the eNodeB will use in the random access procedure, while a communication device in sleep time has no idea of the TDD configuration to be used. Therefore, these two different scenarios should be handled differently. According to one or more embodiments of the present disclosure, a communication device that has lost synchronization and does not detect the TDD configuration notified by the eNodeB in explicit signaling can use the TDD configuration in the SIB to perform a random access procedure, while a communication device that has lost synchronization and detects the TDD configuration notified by the eNodeB in explicit signaling can use the TDD configuration in the explicit signaling to perform a random access procedure.

6 to 9 , various embodiments of Solution 2 of the present disclosure are described in detail.

FIG6 schematically illustrates an example flow chart of a method ( 600 ) for random access in an out-of-sync communication device according to one or more embodiments of the present disclosure.

As shown in FIG6 , in block S610, a communication device, such as the communication device 110 shown in FIG1A and FIG1B , determines whether to receive explicit signaling indicating a TDD configuration. The communication device may be configured to receive explicit signaling from a network node device, such as the eNodeB 120 shown in FIG1A and FIG1B . When the out-of-sync communication device is in sleep time, the communication device may miss the explicit signaling.

In block S620 , the communication device selects a random access preamble based on the determination result of block S610 .

According to one or more embodiments, in a contention-based random access procedure, a communications device may, in response to determining in block S610 that explicit signaling has been received, select a random access preamble from a predefined subset of available random access preambles in a cell served by a network node device. In response to determining in block S610 that explicit signaling has not been received, the communications device may select a random access preamble that does not belong to the predefined subset of available random access preambles in the cell. Since the network node device is also aware of the predefined preamble subset, the communications device can notify the network node device of whether explicit signaling has been received by using the selected preamble.

In block S630, the communication device sends a first message (MSG1) for a random access procedure including the random access preamble selected in block S620 to the network node device according to the TDD configuration in the SIB.

In block S640, the communication device performs subsequent message reception and transmission for the random access procedure according to the TDD configuration determined based on the determination result. Here, "subsequent message reception and transmission" refers to receiving or sending messages for the random access procedure after MSG1, including but not limited to MSG2/3/4 shown in Figures 1A and 1B.

According to one or more embodiments of the present disclosure, the communication device may, in response to determining in block S610 that explicit signaling is received, perform subsequent message reception and transmission for a random access procedure according to the TDD configuration indicated by the explicit signaling. In a contention-based random access procedure, the communication device may use the TDD configuration indicated by the explicit signaling to transmit or receive MSG2/MSG3/MSG4 to or from a network node device. In response to determining in block S610 that explicit signaling is not received, the communication device may perform subsequent message reception and transmission for a subsequent access procedure according to the TDD configuration in the SIB. In a contention-based random access procedure, the communication device may use the TDD configuration in the SIB to transmit or receive MSG2/MSG3/MSG4 to or from a network node device.

According to one or more embodiments of the present disclosure, in a contention-free random access procedure, explicit signaling may be configured to be transmitted in the same message, such as MSG0, as a random access preamble assigned to a communication device. In those embodiments of the present disclosure, if the communication device determines in block S610 that explicit signaling has been received, the communication device may select a random access preamble assigned to the out-of-sync communication device in block 620 to notify the network node device that the communication device has received the explicit signaling. The communication device may then perform subsequent messaging for the random access procedure according to the TDD configuration indicated by the explicit signaling, i.e., receive a random access response by monitoring the downlink channel according to the TDD configuration indicated by the explicit signaling.

In some embodiments, in the case where the communication device does not receive explicit signaling, the communication device also misses the preamble assignment transmitted from the network node device for the contention-free random access procedure and fails to access the network.

FIG7 schematically illustrates an example flow chart of a method 700 for random access in a network node device according to one or more embodiments of the present disclosure.

As shown in FIG. 7 , in block S710 , a network node device, such as the eNodeB 120 as shown in FIG. 1A and FIG. 1B , sends explicit signaling to the out-of-sync communication device indicating a TDD configuration to be used, for example, in a random access procedure.

In block S720, the network node device receives a first message (MSG1) for a random access procedure including a random access preamble from the out-of-sync communication device according to the TDD configuration in the SIB.

In block S730 , the network node device determines whether the out-of-sync communication device has received explicit signaling based on the received random access preamble.

According to one or more embodiments of the present disclosure, in a contention-based random access process, if the received random preamble belongs to a predefined subset of available random access preambles in a cell served by the network node device, the network node device can determine that the out-of-sync communication device has received explicit signaling; and if the received random preamble does not belong to a predefined subset of available random access preambles in the cell, the network node device can determine that the out-of-sync communication device has not received explicit signaling.

In block S740 , the network node device performs subsequent messaging for the random access procedure according to the TDD configuration determined based on the result of the determination in block S730 .

According to one or more embodiments of the present disclosure, in response to determining in block S730 that the out-of-sync communication device has received explicit signaling, the network node device performs subsequent message reception and transmission for the random access procedure according to the TDD configuration indicated by the explicit signaling. In a contention-based random access procedure, the network node device may use the TDD configuration in the explicit signaling to transmit or receive MSG2/MSG3/MSG4 to or from the communication device. In response to determining in block S730 that the out-of-sync communication device has not received explicit signaling, the network node device may perform subsequent message reception and transmission for the random access procedure according to the TDD configuration in the SIB. In a contention-based random access procedure, the network node device may use the TDD configuration in the SIB to transmit or receive MSG2/MSG3/MSG4 to or from the communication device.

According to one or more embodiments of the present disclosure, in a contention-free random access procedure, explicit signaling may be configured to be transmitted in the same message, such as MSG0, as a random access preamble assigned to a communication device that is out of sync. In those embodiments, if the received random access preamble is a random access preamble assigned to a communication device that is out of sync, the network node device may determine, in block S730, that the communication device that is out of sync has received explicit signaling. In response to determining that the communication device that is out of sync has received explicit signaling, the random access preamble may perform subsequent message reception and transmission for the random access procedure according to the TDD configuration indicated by the explicit signaling, i.e., send a random access response according to the TDD configuration indicated by the explicit signaling.

In those embodiments, in the event that the communication device does not receive explicit signaling, the communication device also misses the preamble assignment transmitted from the network node device for the contention-free random access procedure and fails to access the network.

FIG8 is a block diagram schematically illustrating a communication device 800 according to one or more embodiments of the present disclosure.

As shown in FIG8 , a communication device 800, such as the UE 110 shown in FIG1A and FIG1B , includes a transmitting unit 810 and a receiving unit 820 for communicating with a network node device, such as the eNodeB 120 shown in FIG1A and FIG1B . The transmitting unit 810 and the receiving unit 820 may include any appropriate hardware components for bidirectional wireless communication with the network node device. For example, the transmitting unit 810 and the receiving unit 820 may be implemented as an appropriate radio frequency transceiver (i.e., may be implemented as a single component or as separate transmitters and receivers) for bidirectional wireless communication with the network node device via one or more antennas (not shown in FIG8 ).

The receiving unit 820 may be configured to receive explicit signaling indicating the TDD configuration when the communication device 800 is in the active time.

The network node device 800 also includes a processor 80, which includes one or more microprocessors or microcontrollers and other digital hardware, which may include a digital signal processor (DSP), dedicated digital logic, etc. The processor 80 can be configured to execute program code stored in a memory (not shown in FIG8 ), which may include one or more types of memory, such as read-only memory (ROM), random access memory, cache memory, flash memory device, optical storage device, etc. The program code stored in the memory includes program instructions for executing one or more remote communication and/or data communication protocols and instructions for implementing one or more of the technologies described herein in several embodiments.

According to one embodiment of the present disclosure, one functional aspect of the processor 80 may include a selection unit 830 and a determination unit 840. The determination unit 840 is configured to determine whether the receiving unit has received explicit signaling indicating a TDD configuration. The selection unit 830 is configured to select a random access preamble based on the determination result of the determination unit 840.

The sending unit 810 is configured to send a first message (MSG1) for a random access procedure including a random access preamble selected by the selecting unit 830 to the network node device according to the TDD configuration in the SIB.

The transmitting unit 810 and the receiving unit 820 are further configured to perform subsequent message transmission and reception for the random access procedure according to the TDD configuration determined based on the determination result of the determining unit 840 .

According to one or more embodiments of the present disclosure, in a contention-based random access procedure, the selection unit 830 may be configured to select a random access preamble belonging to a predefined subset of available random access preambles in a cell served by a network node device in response to determining that the reception unit 820 has received explicit signaling. In response to determining that the reception unit 820 has not received explicit signaling, the selection unit 830 may be configured to select a random access preamble that does not belong to the predefined subset of available random access preambles in the cell. Since the network node device also knows the predefined preamble subset, the communication device 800 can notify the network node device of whether explicit signaling has been received by using the selected preamble.

According to one or more embodiments of the present disclosure, in a contention-based random access procedure, the transmitting unit 810 and the receiving unit 820 may be configured to, in response to determining that the receiving unit 820 has received explicit signaling, perform subsequent messaging for the random access procedure according to the TDD configuration indicated by the explicit signaling. Thus, the transmitting unit 810 and the receiving unit 820 may be configured to receive or transmit MSG2/MSG3/MSG4 from or to a network node device using the TDD configuration indicated by the explicit signaling. In response to determining that the receiving unit 820 has not received explicit signaling, the transmitting unit 810 and the receiving unit 820 may be configured to perform subsequent messaging for the random access procedure according to the TDD configuration in the SIB. Thus, the transmitting unit 810 and the receiving unit 820 may be configured to receive or transmit MSG2/MSG3/MSG4 from or to a network node device using the TDD configuration in the SIB.

According to one or more embodiments of the present disclosure, in a contention-free random access procedure, explicit signaling may be configured to be transmitted in the same message, such as MSG0, as a random access preamble assigned to a communication device. In those embodiments of the present disclosure, if the determination unit 840 determines that the reception unit 820 receives explicit signaling, the selection unit 830 may be configured to select a random access preamble assigned to a desynchronized communication device to notify the network node device that the communication device has received the explicit signaling. The transmission unit 810 and the reception unit 820 may then be configured to perform subsequent messaging for the random access procedure according to the TDD configuration indicated by the explicit signaling, i.e., to receive a random access response by monitoring the downlink channel according to the TDD configuration indicated by the explicit signaling.

In those embodiments, if the communication device does not receive explicit signaling, the communication device will also miss the preamble assignment transmitted from the network node device for the contention-free random access procedure and fail to access the network.

FIG9 is a block diagram schematically illustrating a network node device 900 according to one or more embodiments of the present disclosure.

As shown in FIG9 , a network node device 900, such as the eNodeB 120 shown in FIG1A and FIG1B , includes a transmitting unit 910 and a receiving unit 920 for communicating with a communication device, such as the UE 110 shown in FIG1A and FIG1B . The transmitting unit 910 and the receiving unit 920 may include any suitable hardware components for bidirectional wireless communication with one or more communication devices. For example, the transmitting unit 910 and the receiving unit 920 may be implemented as a suitable radio frequency transceiver (i.e., may be implemented as a single component or as separate transmitters and receivers) for bidirectional wireless communication with one or more communication devices via one or more antennas (not shown in FIG9 ).

The sending unit 910 is configured to send explicit signaling indicating the TDD configuration to the out-of-synchronization communication device.

The receiving unit 920 is configured to receive a first message (MSG1) for a random access procedure including a random access preamble from a desynchronized communication device according to a TDD configuration in a SIB.

The network node device 900 also includes a processor 90, which includes one or more microprocessors or microcontrollers and other digital hardware, which may include a digital signal processor (DSP), dedicated digital logic, etc. The processor 90 can be configured to execute program code stored in a memory (not shown in FIG. 9 ), which may include one or more types of memory, such as read-only memory (ROM), random access memory, cache memory, flash memory device, optical storage device, etc. In several embodiments, the program code stored in the memory includes program instructions for executing one or more remote communication and/or data communication protocols and instructions for implementing one or more of the technologies described herein.

According to an embodiment of the present disclosure, a functional aspect of the processor 90 may include a determining unit 930 configured to determine whether the out-of-sync communication device receives explicit signaling based on the random access preamble received by the receiving unit 920 .

The transmitting unit 910 and the receiving unit 920 are configured to perform subsequent message transmission and reception for the random access procedure according to the TDD configuration determined based on the determination result of the determining unit 930 .

According to one or more embodiments of the present disclosure, in a contention-based random access procedure, the determining unit 930 may be configured to determine that the out-of-sync communication device has received explicit signaling if the random access preamble received by the receiving unit 920 belongs to a predefined subset of available random access preambles in the cell. The determining unit 930 may be configured to determine that the out-of-sync communication device has not received explicit signaling if the random access preamble received by the receiving unit 920 does not belong to the predefined subset of available random access preambles in the cell.

According to one or more embodiments of the present disclosure, in response to determining that the out-of-sync communication device receives explicit signaling, the transmitting unit 910 and the receiving unit 920 may be configured to perform subsequent messaging for a random access procedure according to the TDD configuration indicated by the explicit signaling. In a contention-based random access procedure, the transmitting unit 910 and the receiving unit 920 may transmit or receive MSG2/MSG3/MSG4 to or from the communication device using the TDD configuration in the explicit signaling. In response to determining that the out-of-sync communication device does not receive explicit signaling, the transmitting unit 910 and the receiving unit 920 may be configured to perform subsequent messaging for the random access procedure according to the TDD configuration in the SIB. In a contention-based random access procedure, the transmitting unit 910 and the receiving unit 920 may transmit or receive MSG2/MSG3/MSG4 to or from the communication device using the TDD configuration in the SIB.

According to one or more embodiments of the present disclosure, in a contention-free random access procedure, explicit signaling may be configured to be transmitted in the same message (e.g., MSG0) as the random access preamble assigned to the out-of-sync communication device. The determining unit 930 may be configured to determine that the out-of-sync communication device has received the explicit signaling if the random access preamble is the random access preamble assigned to the out-of-sync communication device. In response to determining that the out-of-sync communication device has received the explicit signaling, the transmitting unit 910 and the receiving unit 920 may be configured to perform subsequent message transmission for the random access procedure according to the TDD configuration indicated by the explicit signaling, i.e., to transmit a random access response according to the TDD configuration in the explicit signaling.

In these embodiments, if the communication device does not receive explicit signaling, the communication device will also miss the preamble assignment transmitted from the network node device for the contention-free random access procedure, and the random access procedure will fail. According to one or more embodiments of the present disclosure, when a communication device initiates a random access procedure in a dynamic TDD scenario, the communication device and the corresponding network node device, such as an eNodeB, can use a consistent TDD configuration in the SIB or explicit signaling to perform message reception and reception for the random access procedure. In these approaches, random access failures of out-of-sync communication devices in dynamic TDD scenarios can be significantly reduced.

Solution 3 for Carrier Aggregation (CA)

When using carrier aggregation (CA), a communications device can communicate via a primary cell (PCell) and one or more secondary cells (SCells), which together form the serving cell set for the communications device. The component carriers (CCs) of the PCell and SCells aggregated for the communications device typically originate from the same network node device, such as an eNodeB, and those CCs are synchronized. The communications device can be configured to separately and independently operate in a dynamic TDD-capable mode in the PCell and SCells.

A network node device, such as an eNodeB, can instruct a communication device to enable a dynamic TDD-capable mode in the SCell via RRC signaling, such as RRCConnectionReconfiguration. Upon receiving the RRC signaling instructed by the network node device, the communication device needs to notify the network node device that it has enabled a dynamic TDD-capable mode in their communications through the SCell. Once the network node device has received the communication device's confirmation, it communicates with the communication device through the SCell in the dynamic TDD-capable mode. On the communication device side, before it understands that the network node device has received its confirmation, it communicates with the network node device in the SCell according to the TDD configuration in the SIB.

However, before enabling dynamic TDD-capable mode in the SCell, there is uncertainty about the TDD configuration for message exchanges between the network node device and the communication device, as the communication device may have been pre-assigned more than one TDD configuration. In Solution 3 of the present disclosure, similar to Solution 1, a TDD configuration in a SIB broadcast by the network node device can be selected and used to perform signaling exchanges between the network node device and the communication device before establishing dynamic TDD communication.

10 to 13 , various embodiments of Solution 3 of the present disclosure are described in detail.

FIG10 schematically illustrates an example flow chart of a method 1000 for operating a network node device according to one or more embodiments of the present disclosure.

As shown in Figure 10, in step S1010, a network node device, such as an eNodeB, that serves a communication device through at least one secondary cell in carrier aggregation sends RRC signaling to the communication device according to the TDD configuration in the SIB to instruct the communication device to enable a mode capable of dynamic TDD.

In step S1020 , the network node device receives, from the communication device according to the TDD configuration in the SIB, a confirmation indication that the communication device has received the RRC signaling.

In step S1030 , the network node device is controlled to communicate with the communication device through the SCell according to a dynamic TDD-capable mode so as to support multiple dynamic TDD configurations.

The network node device may use implicit signaling to inform the communication device that it has received an acknowledgement indication from the communication device, so that the communication device may understand that the network node device has been switched to a dynamic TDD capable mode in their communication over the SCell.

FIG11 schematically illustrates an example flow chart of a method 1100 for operating a communication device according to one or more embodiments of the present disclosure.

As shown in Figure 11, in step S1110, a communication device, such as a UE, served by a network node device via at least one secondary cell in carrier aggregation receives RRC signaling from the network node device according to the TDD configuration in the SIB. The RRC signaling is used to instruct the communication device to enable a dynamic TDD-capable mode.

In step S1120 , the communication device sends an acknowledgment indication to the network node device according to the TDD configuration in the SIB to indicate that it has received the RRC signaling.

In step S1130 , it is determined whether the network node device has received a confirmation indication.

According to one embodiment of the present disclosure, a communication device may determine whether its scheduling information is detected in a UE-specific search space or a common search space. If the scheduling information from the network node device is detected in the UE-specific search space, it is determined that the network node device has received an acknowledgment indication and has switched to a mode capable of dynamic TDD; if the scheduling information from the network node device is detected in the common search space, it is determined that the network node device has not received an acknowledgment indication and has not switched to a mode capable of dynamic TDD.

According to one embodiment of the present disclosure, a communication device may perform a determination based on a radio network temporary identifier (RNTI) sent by a network node device on a control channel, such as a physical downlink control channel (PDCCH). The network node device may use the RNTI as implicit signaling to indicate whether it has received an acknowledgment indication from the communication device and has switched to a mode capable of dynamic TDD. For example, an RNTI may be selected to indicate that the network node device has received an acknowledgment indication, while another different RNTI may be selected to indicate that the network node device has not received an acknowledgment indication.

According to one embodiment of the present disclosure, a communication device may perform a determination based on a DCI format transmitted by a network node device on a control channel. The network node device may use the DCI format as implicit signaling to indicate whether it has received an acknowledgment indication from the communication device and has switched to a mode capable of dynamic TDD. For example, a DCI format may be selected to indicate that the network node device has received an acknowledgment indication, while a different DCI format may be selected to indicate that the network node device has not received an acknowledgment indication.

In step S1140 , in response to the network node device having received the confirmation indication, the communication device communicates with the network node device according to the dynamic TDD-capable mode to support multiple dynamic TDD configurations.

In step S1150 , in response to determining that the network node device has not received the confirmation indication, the communication device communicates with the network node device according to the TDD configuration in the SIB.

FIG12 is a block diagram schematically illustrating a network node device 1200 according to one or more embodiments of the present disclosure.

As shown in FIG12 , a network node device 1200 serving a communication device via at least one secondary cell in carrier aggregation includes a transmitting unit 1210 and a receiving unit 1220. The transmitting unit 1210 and the receiving unit 1220 may include any appropriate hardware components for bidirectional wireless communication with one or more communication devices. For example, the transmitting unit 1210 and the receiving unit 1220 may be implemented as an appropriate radio frequency transceiver (i.e., may be implemented as a single component or as separate transmitters and receivers) for bidirectional wireless communication with one or more communication devices via one or more antennas (not shown in FIG12 ).

The sending unit 1210 is configured to send RRC signaling to the communication device according to the TDD configuration in the SIB to instruct the communication device to enable a mode capable of dynamic TDD.

The receiving unit 1220 is configured to receive a confirmation indication from the communication device that it enables a dynamic TDD-capable mode according to the TDD configuration in the SIB.

The network node device 1200 also includes a processor 1201, which includes one or more microprocessors or microcontrollers and other digital hardware, which may include a digital signal processor (DSP), dedicated digital logic, etc. The processor 1201 can be configured to execute program code stored in a memory (not shown in FIG12 ), which may include one or more types of memory, such as read-only memory (ROM), random access memory, cache memory, flash memory device, optical storage device, etc. In several embodiments, the program code stored in the memory includes program instructions for executing one or more remote communication and/or data communication protocols and instructions for implementing one or more of the technologies described herein.

According to one embodiment of the present disclosure, one functional aspect of the processor 1201 includes a control unit 1230. The control unit 1230 is configured to control the transmitting unit 1210 and the receiving unit 1220 of the network node 1200 to communicate with the communication device according to a dynamic TDD-capable mode to support multiple dynamic TDD configurations.

The control unit 1230 of the network node device 1200 may control the transmitting unit 1210 to use implicit signaling to notify the communication device that it has received an acknowledgement indication from the communication device and switched to a mode capable of dynamic TDD.

FIG13 is a block diagram schematically illustrating a communication device 1300 according to one or more aspects of the present disclosure.

As shown in FIG13 , a communication device 1300 served by a network node device via at least one secondary cell in carrier aggregation includes a receiving unit 1310 and a transmitting unit 1320. The receiving unit 1310 and the transmitting unit 1320 may include any appropriate hardware components for bidirectional wireless communication with one or more communication devices. For example, the receiving unit 1310 and the transmitting unit 1320 may be implemented as an appropriate radio frequency transceiver (i.e., may be implemented as a single component or as separate transmitters and receivers) for bidirectional wireless communication with one or more communication devices via one or more antennas (not shown in FIG13 ).

The receiving unit 1310 is configured to receive RRC signaling from a network node device according to the TDD configuration in the SIB. The RRC signaling is used to instruct communication devices to enable a dynamic TDD-capable mode in their communications through the SCell.

The sending unit 1320 is configured to send a confirmation indication to the network node device according to the TDD configuration in the SIB to indicate that it has enabled a dynamic TDD-capable mode in their communication through the SCell.

The communication device 1300 also includes a processor 1301, which includes one or more microprocessors or microcontrollers and other digital hardware, which may include a digital signal processor (DSP), dedicated digital logic, etc. The processor 1301 can be configured to execute program code stored in a memory (not shown in FIG13 ), which may include one or more types of memory, such as read-only memory (ROM), random access memory, cache memory, flash memory devices, optical storage devices, etc. The program code stored in the memory includes, in several embodiments, program instructions for executing one or more telecommunication and/or data communication protocols and instructions for implementing one or more of the techniques described herein.

According to one embodiment of the present disclosure, one functional aspect of the processor 1301 may include a determining unit 1330 and a control unit 1340 .

The determining unit 1330 is configured to determine whether the network node device 1300 has received a confirmation indication.

According to one embodiment of the present disclosure, the determination unit 1330 may perform the determination based on whether the scheduling information of the communication device is detected in the UE-specific search space or in the public search space. If the scheduling information from the network node device is detected in the UE-specific search space, the determination unit 1330 may determine that the network node device has received an acknowledgment indication and has switched to a mode capable of dynamic TDD; if the scheduling information from the network node device is detected in the public search space, the determination unit 1330 may determine that the network node device has not received an acknowledgment indication and has not switched to a mode capable of dynamic TDD.

According to one embodiment of the present disclosure, the determining unit 1330 may perform the determination based on a radio network temporary identifier (RNTI) sent by the network node device on a control channel, such as a physical downlink control channel (PDCCH). The network node device may use the RNTI as implicit signaling to indicate whether it has received an acknowledgment indication from the communication device and has switched to a mode capable of dynamic TDD. For example, an RNTI may be selected to indicate that the network node device has received an acknowledgment indication, while another different RNTI may be selected to indicate that the network node device has not received an acknowledgment indication.

According to one embodiment of the present disclosure, the determination unit 1330 may perform the determination based on a DCI format sent by the network node device on the control channel. The network node device may use the DCI format as implicit signaling to indicate whether it has received an acknowledgment indication from the communication device and has switched to a mode capable of dynamic TDD. For example, a DCI format may be selected to indicate that the network node device has received an acknowledgment indication, while another different DCI format may be selected to indicate that the network node device has not received an acknowledgment indication.

The control unit 1340 is configured to control the receiving unit 1310 and the sending unit 1320 to communicate with the network node device through the SCell according to the dynamic TDD capable mode in response to the determining unit 1330 determining that the network node device has received the confirmation indication to support multiple dynamic TDD configurations.

The control unit 1340 is configured to control the receiving unit 1310 and the sending unit 1320 to communicate with the network node device in the SCell according to the TDD configuration in the SIB in response to the determining unit 1330 determining that the network node device has not received the confirmation indication.

According to one or more embodiments of the present disclosure, before enabling a dynamic TDD-capable mode in an SCell, TDD configuration uncertainty can be effectively eliminated for message exchanges between a network node device and a communication device.

In general, various example embodiments may be implemented in hardware or dedicated circuitry, software, logic, or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device, but the disclosure is not limited thereto. Although various aspects of example embodiments of the present disclosure may be illustrated and described as block diagrams and signaling diagrams, it is reasonably understood that the blocks, devices, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware, or a controller or other computing device, or some combination thereof, as non-limiting examples.

As such, it should be appreciated that at least some aspects of the example embodiments of the disclosure may be implemented in various components, such as integrated circuit chips and modules.As is well known in the art, the design of integrated circuits is primarily a highly automated process.

The present disclosure can also be embedded in a computer program product, which comprises all the features enabling the implementation of the method as described herein, and which when loaded in a computer system can carry out the method.

While the present disclosure has been particularly illustrated and described with reference to preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made thereto without departing from the spirit and scope of the present disclosure.

Claims (30)

1. A method (200) for operating a wireless communication device, comprising: According to the Time Division Duplex (TDD) configuration in the system information block, a first message including a random access preamble is sent to the network node device (S210); According to the TDD configuration in the system information block, the system receives (S220) a second message including a random access response from the network node device using the random access preamble. The wireless communication device is assigned more than one TDD configuration for a cell served by the network node before initiating a random access procedure, and the more than one TDD configuration includes the TDD configuration in the system information block and at least one other TDD configuration notified via dedicated radio resource control signaling. 2. The method (200) according to claim 1, further comprising: In a contention-based random access process, According to the TDD configuration in the system information block, a third message including an identifier specific to the wireless communication device is sent to the network node device (S230). 3. The method (200) according to claim 2, further comprising: Switch the wireless communication device to a mode capable of dynamic TDD to support multiple dynamic TDD configurations; By monitoring the downlink channel according to the plurality of dynamic TDD configurations, the network node device receives (S240) a fourth message including contention resolution. 4. The method (200) according to claim 2, further comprising: According to the TDD configuration in the system information block, a fourth message including contention resolution is received from the network node device (S240); Switch the wireless communication device to a mode that enables dynamic TDD to support multiple dynamic TDD configurations. 5. The method (200) according to any one of claims 3-4, wherein each of the plurality of dynamic TDD configurations has uplink subframes belonging to a subset of uplink subframes of the TDD configuration in the system information block and downlink subframes belonging to a subset of downlink subframes of the other TDD configuration notified via dedicated radio resource control signaling. 6. The method according to any one of claims 1-4, wherein the wireless communication device is switched from a source cell served by the source network node device to a target cell served by the network node device, and The TDD configuration in the system information block is notified from the network node device to the source network node device, and the TDD configuration in the system information block is sent from the source network node device to the wireless communication device via signaling. 7. The method (200) according to any one of claims 1-4, wherein the wireless communication device is a user equipment. 8. The method (200) according to claim 7, wherein the user equipment is in a state of out-of-synchronization or link failure. 9. A method (300) for operating a network node device, comprising: Receive (S310) a first message including a random access preamble from the wireless communication device according to the TDD configuration in the system information block; According to the TDD configuration in the system information block, the wireless communication device sends (S320) a second message including a random access response using the random access preamble. The wireless communication device is assigned more than one cell TDD configuration with respect to the network node before initiating a random access procedure, and the more than one TDD configuration includes the TDD configuration in the system information block and at least one other TDD configuration notified via dedicated radio resource control signaling. 10. The method (300) according to claim 9, further comprising: In a contention-based random access process, According to the TDD configuration in the system information block, a third message including an identifier specific to the wireless communication device is received from the wireless communication device (S330). 11. The method (300) according to claim 10, further comprising: Switch the network node device to a dynamic TDD-enabled mode to support multiple dynamic TDD configurations; A fourth message, including contention resolution, is sent to the wireless communication device according to one of the plurality of dynamic TDD configurations (S340). 12. The method (300) according to claim 10, further comprising: According to the TDD configuration in the system information block, a fourth message including contention resolution is sent to the wireless communication device (S340); Switch the network node device to a dynamic TDD mode to support multiple dynamic TDD configurations. 13. The method (300) according to claim 11 or 12, wherein each of the plurality of dynamic TDD configurations has uplink subframes belonging to a subset of uplink subframes of the TDD configuration in the system information block and downlink subframes belonging to a subset of downlink subframes of the other TDD configuration notified via dedicated radio resource control signaling. 14. The method (300) according to any one of claims 9-12, wherein the network node device serves a target cell from which the wireless communication device is handed over from a source cell served by the source network node device, and The network node device notifies the source network node device of the TDD configuration in the system information block, and the source network node device sends the TDD configuration in the system information block to the wireless communication device via signaling. 15. The method (300) according to any one of claims 9-12, wherein the network node device is a base station. 16. A wireless communication device (400), comprising: The sending unit (410) is configured to send a first message including a random access preamble to the network node device according to the time division duplex (TDD) configuration in the system information block; The receiving unit (420) is configured to receive a second message including a random access response from the network node device using the random access preamble according to the TDD configuration in the system information block. The wireless communication device is assigned more than one cell TDD configuration with respect to the network node prior to the random access procedure, and the more than one TDD configuration includes the TDD configuration in the system information block as well as at least another TDD configuration notified via dedicated radio resource control signaling. 17. The wireless communication device (400) according to claim 16, further comprising: The sending unit (410) is also configured to send a third message, including an identifier specific to the wireless communication device, to the network node device in accordance with the TDD configuration in the system information block during a contention-based random access process. 18. The wireless communication device (400) according to claim 17, further comprising: The control unit (430) is configured to switch the wireless communication device to a dynamic TDD mode to support multiple dynamic TDD configurations; The receiving unit (420) is further configured to receive a fourth message, including contention resolution, from the network node device by monitoring the downlink channel according to the plurality of dynamic TDD configurations. 19. The wireless communication device (400) according to claim 17, wherein: The receiving unit (420) is further configured to receive a fourth message, including contention resolution, from the network node device according to the TDD configuration in the system information block; The wireless communication device (400) further includes a control unit (430) configured to switch the wireless communication device to a dynamic TDD mode to support multiple dynamic TDD configurations. 20. The wireless communication device (400) according to claim 18 or 19, wherein each of the plurality of dynamic TDD configurations has uplink subframes belonging to a subset of uplink subframes of the TDD configuration in the system information block and downlink subframes belonging to a subset of downlink subframes of the other TDD configuration notified via dedicated radio resource control signaling. 21. The wireless communication device (400) according to any one of claims 16-19, wherein the wireless communication device is switched from a source cell served by the source network node device to a target cell served by the network node device, and The network node device notifies the source network node device of the TDD configuration in the system information block, and the source network node device sends the TDD configuration in the system information block to the wireless communication device using signaling. 22. The wireless communication device (400) according to any one of claims 16-19, wherein the wireless communication device is a user equipment. 23. The wireless communication device (400) according to claim 22, wherein the user equipment is in a state of out-of-synchronization or link failure. 24. A network node device (500), comprising: The receiving unit (510) is configured to receive a first message including a random access preamble from the wireless communication device according to the TDD configuration in the system information block; The transmitting unit (520) is configured to transmit a second message including a random access response to the wireless communication device using the random access preamble according to the TDD configuration in the system information block. The network node device is configured to assign more than one cell TDD configuration to the wireless communication device prior to the random access procedure, wherein the more than one TDD configuration includes the TDD configuration in the system information block and also includes at least one other TDD configuration notified via dedicated radio resource control signaling. 25. The network node device (500) of claim 24, wherein the receiving unit (510) is further configured to receive, in a contention-based random access process, a third message including an identifier specific to the wireless communication device from the wireless communication device according to the TDD configuration in the system information block. 26. The network node device (500) according to claim 25, further comprising: The control unit (530) is configured to switch the network node device to a dynamic TDD mode to support multiple dynamic TDD configurations; The transmitting unit (520) is further configured to transmit a fourth message, including contention resolution, to the wireless communication device according to one of the plurality of dynamic TDD configurations. 27. The network node device (500) according to claim 25, wherein: The transmitting unit (520) is further configured to transmit a fourth message, including contention resolution, to the wireless communication device according to the TDD configuration in the system information block; The network node device (500) also includes a control unit (530) configured to switch the network node device to a dynamic TDD mode to support multiple dynamic TDD configurations. 28. The network node device (500) according to claim 26 or 27, wherein each of the plurality of dynamic TDD configurations has uplink subframes belonging to a subset of uplink subframes of the TDD configuration in the system information block and downlink subframes belonging to a subset of downlink subframes of the other TDD configuration notified via dedicated radio resource control signaling. 29. The network node device (500) according to any one of claims 24-27, wherein the network node device serves a target cell from which the wireless communication device is handed over from a source cell served by the source network node device, and The network node device notifies the source network node device of the TDD configuration in the system information block, and the source network node device sends the TDD configuration in the system information block to the wireless communication device using signaling. 30. The network node device (500) according to any one of claims 24-27, wherein the network node device is a base station.