CN106549736A - A kind of cross-carrier rlc layer data repeating method and device - Google Patents

Abstract

The invention discloses a cross-carrier RLC layer data retransmission method and device, the method comprising: receiving an RLC retransmission indication sent when a medium access control MAC entity detects a target authorized cell with available resources; according to the RLC retransmission indication, Sending the RLC layer data that fails to be transmitted by the unlicensed cell to the MAC entity, so that the RLC layer data that fails to be transmitted by the unlicensed cell is retransmitted using available resources of the target authorized cell. In the present invention, when the transmission quality of the unlicensed frequency band is poor and there is RLC layer data that needs to be retransmitted, the target authorized cell with available resources detected by the MAC entity is used to retransmit the RLC layer data that fails to be transmitted in the unlicensed cell. The transmission quality of the cell is reliable, so the reliable transmission of RLC layer data can be guaranteed.

Description

A cross-carrier RLC layer data retransmission method and device

technical field

The invention relates to the field of wireless and LTE communication, in particular to a cross-carrier RLC layer data retransmission method and device.

Background technique

Licensed-Assisted Access (LAA, Licensed-Assisted Access) relies on carrier aggregation technology to ensure a higher data rate by aggregating unlicensed frequency bands into LTE licensed frequency bands. However, since LAA uses the same unlicensed frequency band as WiFi, and different operators can share this frequency band, the channel interference of LAA is serious. Although LAA technology can bring larger channel bandwidth to mobile communication, strong interference seriously affects the performance of LAA system.

In the LTE system, the reliable reception of data is guaranteed through the following two data retransmission methods: one is the Hybrid Automatic Repeat reQuest (HARQ, Hybrid Automatic Repeat reQuest) retransmission process of the Media Access Control (MAC, Media Access Control) layer , and the other is a radio link control (RLC, Radio Link Control) layer retransmission process. The HARQ retransmission technology reduces the negative impact of channel and interference jitter on data transmission by retransmitting multiple versions of the same transmission block. However, applying HARQ retransmission to the LAA system may not achieve its performance in the LTE system, because the LAA system works in an unlicensed frequency band with complex interference. The failure of HARQ retransmission in the LAA system probably means that the current unlicensed channel cannot guarantee highly reliable data reception, especially for error-sensitive services, such as Web browsing and file downloading.

Therefore, a cross-carrier HARQ retransmission scheme was proposed during standardization discussions. The cross-carrier HARQ retransmission scheme uses other carrier resources (licensed carriers or unlicensed carriers) for retransmission. The disadvantage is that the retransmission resources must be sufficient. If the available resources of the target carrier cannot bear all the data of the retransmitted MAC PDU, cross-carrier HARQ retransmission cannot be realized.

Contents of the invention

The present invention provides a cross-carrier RLC layer data retransmission method and device, which solves the problem in the prior art that HARQ retransmission requires many carrier resources when the transmission quality of the unlicensed frequency band is poor.

According to one aspect of the present invention, a cross-carrier RLC layer data retransmission method is provided, which is applied to a radio link control RLC entity, and the method includes:

receiving an RLC retransmission indication sent when the medium access control MAC entity detects a target authorized cell with available resources;

According to the RLC retransmission instruction, send the RLC layer data that failed to be transmitted by the unlicensed cell to the MAC entity, so that the RLC layer data that failed to be transmitted by the unlicensed cell is retransmitted using the available resources of the target authorized cell.

Wherein, before receiving the RLC retransmission indication sent when the medium access control MAC entity detects the target authorized cell with available resources, it also includes:

When receiving the RLC status protocol data unit PDU, prepare for RLC retransmission; or,

When receiving the hybrid automatic repeat request HARQ data retransmission failure indication sent by the MAC entity and the sequence number of the RLC protocol data unit to be retransmitted, prepare for RLC retransmission.

Wherein, receiving the hybrid automatic repeat request HARQ data retransmission failure indication sent by the MAC entity specifically includes:

Receiving the HARQ data retransmission failure indication sent by the MAC entity when the number of HARQ data retransmissions reaches the maximum number of retransmissions; or,

Receiving the HARQ data retransmission failure indication sent by the MAC entity after the HARQ data retransmission time exceeds the maximum retransmission delay.

Wherein, the serial number of the RLC protocol data unit that needs to be retransmitted and sent by the receiving MAC entity specifically includes:

The sequence number of the RLC protocol data unit identified and delivered by the receiving MAC entity; or,

Receive the RLC protocol data unit data delivered by the MAC entity, and identify the corresponding RLC protocol data unit sequence number according to the RLC protocol data unit data.

Among them, the RLC layer data of the transmission failure of the unauthorized cell is sent to the MAC entity, specifically including:

According to the size of the MAC protocol data unit indicated by the MAC entity, segment the RLC layer data of the unauthorized cell transmission failure;

re-encapsulate the RLC layer data that failed to be transmitted in the segmented unlicensed cell;

Delivering the encapsulated RLC layer data that fails to be transmitted in the unlicensed cell to the MAC entity.

According to another aspect of the present invention, a method for retransmitting cross-carrier RLC layer data is also provided, which is applied to a medium access control MAC entity, and the method includes:

An RLC retransmission indication sent to an RLC entity preparing to perform RLC retransmission when a target authorized cell with available resources is detected;

Receiving the RLC layer data that the RLC entity sends according to the RLC retransmission indication and the transmission failure of the unauthorized cell;

The RLC layer data that fails to be transmitted by the unlicensed cell is retransmitted by using available resources of the target authorized cell.

Wherein, before the RLC retransmission instruction sent to the RLC entity preparing to perform RLC retransmission, it also includes:

When HARQ data retransmission failure is detected, an HARQ data retransmission failure indication and the sequence number of the RLC protocol data unit to be retransmitted are sent to the RLC entity.

Among them, it is detected that the hybrid automatic repeat request HARQ data retransmission fails, specifically including:

When it is detected that the number of HARQ data retransmissions reaches the maximum number of retransmissions, the HARQ data retransmission fails; or,

When it is detected that the HARQ data retransmission time exceeds the maximum retransmission delay, the HARQ data retransmission fails.

Wherein, the serial number of the RLC protocol data unit that needs to be retransmitted is sent to the RLC entity, including:

Identify the corresponding RLC protocol data unit sequence number according to the retransmitted RLC layer data, and send the RLC protocol data unit sequence number to the RLC entity; or,

The RLC protocol data unit data sent to the RLC entity, where the corresponding RLC protocol data unit sequence number can be identified according to the RLC protocol data unit data.

Wherein, detecting a target authorized cell with available resources includes:

When it is detected that there are available resources in the authorized cell, determining the authorized cell where the first available resource is located as the target authorized cell; or

Searching for a first authorized cell corresponding to an unauthorized cell that needs to retransmit RLC layer data according to a preset mapping relationship between an unauthorized cell and an authorized cell;

When it is detected that there are available resources in the first authorized cell, it is determined that the first authorized cell is the target authorized cell.

According to another aspect of the present invention, a cross-carrier RLC layer data retransmission device is also provided, which is applied to a radio link control RLC entity, and the device includes:

The first receiving module is configured to receive an RLC retransmission indication sent when a medium access control MAC entity detects a target authorized cell with available resources;

The first sending module is configured to send the RLC layer data that failed to be transmitted by the unlicensed cell to the MAC entity according to the RLC retransmission instruction, so that the RLC layer data that failed to be transmitted by the unlicensed cell is retransmitted using the available resources of the target authorized cell.

Wherein, the cross-carrier RLC layer data retransmission device also includes:

The first processing module is configured to prepare for RLC retransmission when receiving the RLC status protocol data unit PDU; or,

The second processing module is configured to prepare for RLC retransmission when receiving the HARQ data retransmission failure indication sent by the MAC entity and the sequence number of the RLC protocol data unit to be retransmitted.

Wherein, the second processing module specifically includes:

The first receiving unit is configured to receive the HARQ data retransmission failure indication sent by the MAC entity when the number of HARQ data retransmissions reaches the maximum number of retransmissions; or,

The second receiving unit is configured to receive the HARQ data retransmission failure indication sent by the MAC entity after the HARQ data retransmission time exceeds the maximum retransmission time delay.

Wherein, the second processing module specifically includes:

The third receiving unit is configured to receive the serial number of the RLC protocol data unit identified and delivered by the MAC entity; or,

The fourth receiving unit is configured to receive the RLC protocol data unit data delivered by the MAC entity, and identify the corresponding RLC protocol data unit sequence number according to the RLC protocol data unit data.

Wherein, the first sending module includes:

The segmentation unit is used to segment the RLC layer data whose transmission fails in the unlicensed cell according to the size of the MAC protocol data unit indicated by the MAC entity;

An encapsulation unit, configured to re-encapsulate RLC layer data that fails to be transmitted in the segmented unlicensed cell;

The first sending unit is configured to deliver the encapsulated RLC layer data of the failed transmission of the unlicensed cell to the MAC entity.

According to another aspect of the present invention, a cross-carrier RLC layer data retransmission device is also provided, which is applied to a medium access control MAC entity, and the device includes:

The second sending module is used to send an RLC retransmission indication to an RLC entity preparing to perform RLC retransmission when a target authorized cell with available resources is detected;

The second receiving module is used to receive the RLC layer data sent by the RLC entity according to the RLC retransmission indication that the transmission of the unauthorized cell failed;

The retransmission module is used to retransmit the RLC layer data that failed to be transmitted by the unlicensed cell by utilizing the available resources of the target authorized cell.

Wherein, the cross-carrier RLC layer data retransmission device also includes:

The third sending module is configured to send a HARQ data retransmission failure indication and the sequence number of the RLC protocol data unit to be retransmitted to the RLC entity when the HARQ data retransmission failure is detected.

Wherein, the third sending module includes:

The first sending unit is configured to identify the corresponding RLC protocol data unit serial number according to the retransmitted RLC layer data, and send the RLC protocol data unit serial number to the RLC entity; or,

The second sending unit is configured to send the RLC protocol data unit data to the RLC entity, where the corresponding RLC protocol data unit serial number can be identified according to the RLC protocol data unit data.

Wherein, the cross-carrier RLC layer data retransmission device also includes:

The first confirming module is configured to, when it is detected that there are available resources in the authorized cell, determine the authorized cell where the first available resource is located as the target authorized cell; or

A search module, configured to search for a first authorized cell corresponding to an unlicensed cell that needs to retransmit RLC layer data according to a preset mapping relationship between an unlicensed cell and an authorized cell;

The second confirming module is configured to determine that the first authorized cell is a target authorized cell when it is detected that there are available resources in the first authorized cell.

The beneficial effects of the embodiments of the present invention are:

When the transmission quality of the unlicensed frequency band is poor and there is RLC layer data that needs to be retransmitted, the target licensed cell with available resources detected by the MAC entity is used to retransmit the RLC layer data that failed to be transmitted by the unlicensed cell. The transmission quality is reliable, so the timeliness and reliability of RLC layer data retransmission can be guaranteed.

Description of drawings

Fig. 1 shows the schematic flow chart of the method for retransmitting RLC layer data across carriers at the RLC entity end of the present invention;

Fig. 2 shows the schematic flow chart of the MAC entity end cross-carrier RLC layer data retransmission method of the present invention;

FIG. 3 shows a schematic diagram of dynamically selecting retransmission resources in the present invention;

Fig. 4 shows the schematic diagram of RLC layer data segmentation of the present invention;

FIG. 5 shows a schematic diagram of statically selected retransmission resources in the present invention;

FIG. 6 shows a schematic flow diagram of the cross-carrier RLC layer data retransmission method of the present invention;

7 shows a schematic flow diagram of the RLC entity terminal cross-carrier RLC layer data retransmission device of the present invention;

FIG. 8 shows a schematic flowchart of the device for retransmitting RLC layer data across carriers at the MAC entity end in the present invention.

detailed description

Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the invention may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided for more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

In order to solve the problem of poor transmission quality in unlicensed frequency bands and many carrier resources required for HARQ retransmission in the prior art, an embodiment of the present invention provides a cross-carrier RLC layer data retransmission method. The following will control the RLC entity from the radio link The cross-carrier RLC layer data retransmission method is introduced respectively on the side of the medium access control MAC entity and the side of the medium access control MAC entity.

RLC entity side

As shown in Figure 1, the cross-carrier RLC layer data retransmission method specifically includes the following steps:

Step S11: Receive the RLC retransmission indication sent when the MAC entity detects a target authorized cell with available resources.

When the RLC entity enters the state of preparing for RLC retransmission, instruct the MAC entity to detect whether there is a target authorized cell with available resources; when the MAC entity detects a target authorized cell with available resources, receive the RLC retransmission instruction sent from the MAC entity .

Step S12: According to the RLC retransmission instruction, send the RLC layer data that failed to be transmitted by the unlicensed cell to the MAC entity, so that the RLC layer data that failed to be transmitted by the unlicensed cell is retransmitted using the available resources of the target authorized cell.

After receiving the RLC retransmission instruction sent by the MAC entity, send the RLC layer data (RLC PDU) that the unlicensed cell failed to transmit to the MAC entity end, so that the RLC layer data that the unlicensed cell failed to transmit can be authorized by the target through the MAC entity. available resources of the cell for retransmission.

It is worth pointing out that the RLC entity and the MAC entity mentioned in this embodiment can be applied to both the user terminal side and the base station side. When it is on the user terminal side, it means that the uplink data transmission of the unlicensed cell fails. When retransmitting data at the RLC layer, it is necessary to detect whether there is an authorized target cell with available uplink resources; when it is on the base station side, it means that the downlink data transmission of the unlicensed cell When data transmission fails and RLC retransmission is performed, it is necessary to detect whether there is an authorized target cell with available downlink resources.

Wherein, before step S11, it also includes: preparing for RLC retransmission according to the received radio link control RLC retransmission request; its specific implementation can refer to the following two ways:

Way 1: specifically includes: preparing for RLC retransmission when an RLC status protocol data unit PDU is received.

Wherein, the RLC status protocol data unit PDU is sent by the peer RLC entity, and the peer RLC entity refers to the receiving end RLC entity corresponding to the sending end RLC entity.

Method 2: specifically includes: preparing for RLC retransmission when receiving the hybrid automatic repeat request HARQ data retransmission failure indication sent by the MAC entity and the sequence number of the RLC protocol data unit to be retransmitted.

Here it means that when the retransmission request is an HARQ retransmission failure indication triggered by the MAC entity, the RLC layer also needs to obtain the serial number of the RLC protocol data unit to be retransmitted from the MAC entity.

Specifically, receiving the hybrid automatic repeat request HARQ data retransmission failure indication sent by the MAC entity specifically includes:

Receiving the HARQ data retransmission failure indication sent by the MAC entity when the HARQ data retransmission times reach the maximum retransmission times.

A maximum number of HARQ retransmissions is preset, and when the number of HARQ data retransmissions reaches the maximum number of retransmissions, it means that the HARQ retransmission fails.

Or, receive the HARQ data retransmission failure indication sent by the MAC entity after the HARQ data retransmission time exceeds the maximum retransmission time delay.

The MAC entity at the sending end and the MAC entity at the receiving end maintain a HARQ retransmission timer of the same length for each HARQ process. During the validity period of the HARQ retransmission timer, the number of HARQ retransmissions is not limited. Once the HARQ retransmission timer expires, it means that the HARQ retransmission fails. Since the lengths of the HARQ retransmission timers maintained by the MAC entity of the sending end and the MAC entity of the receiving end are the same, the sending end and the receiving end can be informed of the HARQ retransmission failure at the same time. Wherein, the length of the HARQ retransmission timer can be issued through RRC signaling, or can be set through a certain field of MAC-MainConfig (for example, a new field similar to maxHARQ-Tx).

Specifically, the sequence number of the RLC protocol data unit that needs to be retransmitted is obtained from the MAC entity

Receive the serial number of the RLC protocol data unit identified and delivered by the MAC entity; this step can be realized through the demultiplexing function of the MAC layer: the serial number of the RLC protocol data unit can be identified by the MAC layer and delivered to the RLC layer.

Alternatively, the MAC layer demultiplexing function is used to receive the RLC protocol data unit data delivered by the MAC entity, and identify the corresponding RLC protocol data unit sequence number according to the RLC protocol data unit data.

Among them, since the RLC layer has a segmentation function, when the retransmission data is larger than the retransmission resource, the retransmission data can be segmented and retransmitted, specifically including:

According to the size of the MAC protocol data unit indicated by the MAC entity, the RLC layer data whose transmission fails in the unauthorized cell is segmented to match the size of the MAC protocol data unit indicated by the MAC layer.

Re-encapsulate the segmented RLC layer data that fails to be transmitted in the unauthorized cell, which refers to adding an RLC header to the segmented RLC layer data respectively, and encapsulating it as new RLC layer data.

The encapsulated RLC layer data whose transmission failed in the unauthorized cell is delivered to the MAC entity, the new RLC layer data matches the size of the MAC protocol data unit, and the RLC layer data is retransmitted through the available transmission resources.

The above describes the cross-carrier RLC layer data retransmission method from the RLC entity side, and the following will further describe the cross-carrier RLC layer data retransmission method from the MAC entity side.

MAC entity side

As shown in Figure 2, the cross-carrier RLC layer data retransmission method specifically includes the following steps:

Step S21: when a target licensed cell with available resources is detected, an RLC retransmission indication is sent to the RLC entity preparing for RLC retransmission.

When the RLC layer data transmission of the unlicensed cell fails, the RLC entity will receive an RLC retransmission request, and then prepare for RLC retransmission. At this time, the MAC entity will detect whether there is currently a target authorized cell with available resources; The RLC retransmission indication sent by the MAC entity to the RLC entity preparing to perform RLC retransmission when the target licensed cell with available resources is reached.

Step S22: receiving the RLC layer data sent by the RLC entity according to the RLC retransmission indication that the transmission of the unlicensed cell failed.

After receiving the RLC retransmission indication sent by the MAC entity, the RLC entity sends the RLC layer data that the transmission of the unauthorized cell failed to the MAC entity.

Step S23: retransmit the RLC layer data that failed to be transmitted by the unlicensed cell by using the available resources of the target authorized cell.

After the MAC entity receives the RLC layer data sent by the RLC entity that fails to be transmitted by the unlicensed cell, it uses the detected available resources of the target authorized cell to retransmit the RLC layer data that fails to be transmitted by the unlicensed cell.

Wherein, before the RLC retransmission instruction sent to the RLC entity preparing to perform RLC retransmission, it also includes:

When the RLC layer data transmission of the unlicensed cell fails, that is, when the hybrid automatic repeat request HARQ data retransmission failure is detected, an HARQ data retransmission failure indication and the RLC protocol data unit sequence number to be retransmitted are sent to the RLC entity.

Among them, it is detected that the hybrid automatic repeat request HARQ data retransmission fails, specifically including:

When it is detected that the number of retransmissions of the HARQ data reaches the maximum number of retransmissions, the retransmission of the HARQ data fails.

Or, when it is detected that the HARQ data retransmission time exceeds the maximum retransmission delay, the HARQ data retransmission fails.

Wherein, the serial number of the RLC protocol data unit that needs to be retransmitted is sent to the RLC entity, including:

Identify the corresponding RLC PDU sequence number according to the retransmitted RLC layer data, and send the RLC PDU sequence number to the RLC entity.

Or, the RLC protocol data unit data sent to the RLC entity, where the corresponding RLC protocol data unit sequence number can be identified according to the RLC protocol data unit data.

Wherein, detecting a target authorized cell with available resources is a manner of configuring retransmission resources, which specifically includes a static configuration manner and a dynamic configuration manner.

Wherein, the dynamic configuration method specifically includes: when it is detected that there are available resources in the authorized cell, the authorized cell where the first available resource is located is determined as the target authorized cell.

This means that as long as the available resources do not belong to unauthorized cells, they can be configured as retransmission resources. This step can be understood as that the RLC protocol data units in the RLC retransmission buffer can only be sent through authorized resources. Cross-carrier RLC retransmission can occur on any available licensed cell resource. When the MAC layer recognizes a licensed cell with available resources, it selects the licensed cell where the first available resource is located as the target licensed cell, and instructs the RLC layer to use data The target authorized cell performs RLC layer data retransmission.

Taking the sending end as a user terminal as an example, that is, the situation where the uplink RLC layer data transmission fails, as shown in Figure 3, the base station configures 4 carrier aggregation conditions for the user terminal, that is, one primary cell and two authorized secondary cells (authorized cell 1 and licensed cell 2), and an unlicensed secondary cell. Among them, in the frame structure of the auxiliary cell, subframe 0, subframe 4, subframe 5, and subframe 9 are downlink subframes, subframe 1 and subframe 6 are special subframes, and subframe 2, subframe 3, and subframe 7 are And subframe 8 is an uplink subframe. On subframe 4 of the unlicensed cell, the RLC entity of the user terminal receives the HARQ retransmission failure indication and the sequence number of the RLC PDU to be retransmitted from the lower-layer MAC entity, indicating that cross-carrier RLC retransmission is required. The MAC entity detects that the subframe 8 of the current frame and the subframe 2 of the next frame of the authorized cell 1 are available resources, and the subframe 7 and subframe 8 of the current frame of the authorized cell 2 are available resources. Subframe 7 on cell 2 is authorized as the first available uplink transmission resource, so it is selected as the RLC retransmission resource for cross-carrier RLC retransmission.

Due to the problem that the retransmission data of the RLC layer is larger than the retransmission resource size, the RLC layer data needs to be segmented. Assuming that the size of available resources on subframe 7 of authorized cell 2 cannot meet the requirements for retransmission of RLC layer data, as shown in Figure 4, the RLC entity performs re-segmentation operations on the RLC layer data that needs to be retransmitted to match the requirements indicated by the MAC layer. The size of the MAC Protocol Data Unit (MAC PDU). Since the first available resource (subframe 7) on the authorized cell 2 cannot meet the transmission requirements for retransmitting the RLC layer data, the retransmitting RLC layer data needs to be segmented again. The retransmission of RLC layer data segmentation operation is consistent with the existing mechanism, that is, the RLC layer data that needs to be retransmitted is segmented and reassembled into the new RLC layer data, and then the RLC header is added to the new RLC layer data, and the encapsulation It is the new RLC layer data (RLC PDU1 and RLC PDU2). After being re-segmented and encapsulated by the RLC layer, it is multiplexed to the MAC layer and encapsulated into retransmission data MAC PDU 1 and MAC PDU 2, which are then handed over to the physical layer for transmission to realize the retransmission of RLC layer data.

The dynamic configuration method has been introduced above, and the static configuration method will be further introduced below, specifically: according to the preset mapping relationship between unlicensed cells and authorized cells, search for the first authorized cell corresponding to the unlicensed cell that needs to retransmit RLC layer data .

When it is detected that there are available resources in the first authorized cell, it is determined that the first authorized cell is the target authorized cell.

The target authorized cell may be statically configured, that is, when cross-carrier RLC retransmission is triggered, the retransmission of RLC layer data is always completed on the target authorized cell corresponding to the unlicensed cell whose transmission failed. That is to say, the mapping relationship between each authorized auxiliary cell and one or more authorized cells is pre-configured on the base station side. When cross-carrier RLC retransmission is required on the authorized auxiliary cell, the cross-carrier RLC retransmission process can only occur between on the corresponding authorized cell. Only when the MAC layer of the sending end recognizes that there are available resources in the corresponding authorized cell, it will instruct the RLC layer to multiplex the RLC layer data that needs to be retransmitted to the available resources of the target authorized cell for RLC retransmission.

Taking the sending end as the user terminal as an example, that is, the situation where the uplink RLC layer data transmission fails, as shown in Figure 5, the base station configures 4 carrier aggregation conditions for the user terminal, that is, one primary cell and two authorized secondary cells (authorized cell 1 and licensed cell 2), and an unlicensed secondary cell. Among them, in the frame structure of the auxiliary cell, subframe 0, subframe 4, subframe 5, and subframe 9 are downlink subframes, subframe 1 and subframe 6 are special subframes, and subframe 2, subframe 3, and subframe 7 are And subframe 8 is an uplink subframe. On subframe 4 of the unlicensed cell, the RLC entity of the user terminal receives the HARQ retransmission failure indication and the sequence number of the RLC PDU to be retransmitted from the lower-layer MAC entity, indicating that cross-carrier RLC retransmission is required. The MAC entity detects that the subframe 8 of the current frame and the subframe 2 of the next frame of the authorized cell 1 are available resources, and the subframe 7 and subframe 8 of the current frame of the authorized cell 2 are available resources. Since the retransmission cell of the pre-configured unlicensed cell is the authorized cell 1, even if the subframe 7 on the authorized cell 2 is used as the first available uplink transmission resource, the MAC entity still selects the authorized cell 1 for RLC retransmission. Pass resources.

It is worth noting that the above two methods for determining retransmission resources are not only applicable to the case where the sending end is a user terminal, but also applicable to the case where the sending end is a base station. When the sending end is a base station, the MAC layer should detect whether there is an authorized cell with downlink transmission resources. The specific implementation method is similar to the above example, so it will not be described again.

As shown in Figure 6, the cross-carrier RLC retransmission method specifically includes:

Step 61. After receiving the RLC status PDU sent by the RLC at the receiving end, the RLC at the sending end enters the state of preparing for retransmission;

Step 62. When the MAC at the sending end detects that there is an authorized cell with available resources, the MAC at the sending end sends an RLC retransmission indication to the RLC at the sending end;

Step 63, the sending end RLC sends the RLC layer data to be retransmitted to the sending end MAC;

Step 64: The MAC at the sending end uses the available resources of the selected target authorized cell to retransmit the RLC layer data to the MAC at the receiving end.

To sum up, when the transmission quality of the unlicensed frequency band is poor and there is RLC layer data that needs to be retransmitted, the target licensed cell with available resources detected by the MAC entity is used to retransmit the RLC layer data that failed to be transmitted by the unlicensed cell. The transmission quality of the authorized cell is reliable, so the timeliness and reliability of data retransmission at the RLC layer can be guaranteed.

According to another aspect of the embodiments of the present invention, a cross-carrier RLC layer data retransmission device is also provided, which is applied to a radio link control RLC entity. As shown in FIG. 7, the device includes:

The first receiving module 71 is configured to receive an RLC retransmission indication sent when a medium access control MAC entity detects a target authorized cell with available resources;

The first sending module 72 is configured to send the RLC layer data that failed to be transmitted by the unlicensed cell to the MAC entity according to the RLC retransmission indication, so that the RLC layer data that failed to be transmitted by the unlicensed cell is retransmitted using the available resources of the target licensed cell.

Wherein, the cross-carrier RLC layer data retransmission device also includes:

The first processing module is configured to prepare for RLC retransmission when receiving the RLC status protocol data unit PDU; or,

The second processing module is configured to prepare for RLC retransmission when receiving the HARQ data retransmission failure indication sent by the MAC entity and the sequence number of the RLC protocol data unit to be retransmitted.

Wherein, the second processing module specifically includes:

The first receiving unit is configured to receive the HARQ data retransmission failure indication sent by the MAC entity when the number of HARQ data retransmissions reaches the maximum number of retransmissions; or,

The second receiving unit is configured to receive the HARQ data retransmission failure indication sent by the MAC entity after the HARQ data retransmission time exceeds the maximum retransmission time delay.

Wherein, the second processing module specifically includes:

The third receiving unit is configured to receive the serial number of the RLC protocol data unit identified and delivered by the MAC entity; or,

The fourth receiving unit is configured to receive the RLC protocol data unit data delivered by the MAC entity, and identify the corresponding RLC protocol data unit sequence number according to the RLC protocol data unit data.

Wherein, the first sending module includes:

The segmentation unit is used to segment the RLC layer data whose transmission fails in the unlicensed cell according to the size of the MAC protocol data unit indicated by the MAC entity;

An encapsulation unit, configured to re-encapsulate RLC layer data that fails to be transmitted in the segmented unlicensed cell;

The first sending unit is configured to deliver the encapsulated RLC layer data of the failed transmission of the unlicensed cell to the MAC entity.

According to yet another aspect of the embodiments of the present invention, a cross-carrier RLC layer data retransmission device is also provided, which is applied to a medium access control MAC entity. As shown in FIG. 8, the device includes:

The second sending module 81 is used to send an RLC retransmission indication to an RLC entity preparing to perform RLC retransmission when a target authorized cell with available resources is detected;

The second receiving module 82 is used to receive RLC layer data sent by the RLC entity according to the RLC retransmission indication that the transmission of the unauthorized cell failed;

The retransmission module 83 is configured to use available resources of the target authorized cell to retransmit the RLC layer data that failed to be transmitted by the unauthorized cell.

Wherein, the cross-carrier RLC layer data retransmission device also includes:

The third sending module is configured to send a HARQ data retransmission failure indication and the sequence number of the RLC protocol data unit to be retransmitted to the RLC entity when the HARQ data retransmission failure is detected.

Wherein, the third sending module includes:

The first sending unit is configured to identify the corresponding RLC protocol data unit serial number according to the retransmitted RLC layer data, and send the RLC protocol data unit serial number to the RLC entity; or,

The second sending unit is configured to send the RLC protocol data unit data to the RLC entity, where the corresponding RLC protocol data unit serial number can be identified according to the RLC protocol data unit data.

Wherein, the cross-carrier RLC layer data retransmission device also includes:

The first confirming module is configured to, when it is detected that there are available resources in the authorized cell, determine the authorized cell where the first available resource is located as the target authorized cell; or

A search module, configured to search for a first authorized cell corresponding to an unlicensed cell that needs to retransmit RLC layer data according to a preset mapping relationship between an unlicensed cell and an authorized cell;

The second confirming module is configured to determine that the first authorized cell is a target authorized cell when it is detected that there are available resources in the first authorized cell.

It should be noted that this device is a device corresponding to the above cross-carrier RLC retransmission method, and all the implementation methods in the above method embodiments are applicable to the embodiments of the device, and can also achieve the same technical effect.

What has been described above is a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, some improvements and modifications can also be made without departing from the principles described in the present invention. within the scope of protection of the invention.

Claims (19)

1. A cross-carrier RLC layer data retransmission method, applied to a radio link control RLC entity, is characterized in that, comprising: receiving an RLC retransmission indication sent when the medium access control MAC entity detects a target authorized cell with available resources; According to the RLC retransmission indication, send the RLC layer data that failed to be transmitted by the unlicensed cell to the MAC entity, so that the RLC layer data that failed to be transmitted by the unlicensed cell is retransmitted using the available resources of the target licensed cell. 2. The cross-carrier RLC layer data retransmission method according to claim 1, wherein, before receiving the RLC retransmission indication sent when the medium access control MAC entity detects a target authorized cell with available resources, further comprising: When receiving the RLC status protocol data unit PDU, prepare for RLC retransmission; or, When receiving the hybrid automatic repeat request HARQ data retransmission failure indication sent by the MAC entity and the sequence number of the RLC protocol data unit that needs to be retransmitted, prepare for RLC retransmission. 3. The cross-carrier RLC layer data retransmission method according to claim 2, characterized in that, receiving the hybrid automatic repeat request HARQ data retransmission failure indication sent by the MAC entity specifically includes: Receive the HARQ data retransmission failure indication sent by the MAC entity when the number of HARQ data retransmissions reaches the maximum number of retransmissions; or, Receive the HARQ data retransmission failure indication sent by the MAC entity after the HARQ data retransmission time exceeds the maximum retransmission delay. 4. the cross-carrier RLC layer data retransmission method according to claim 3, is characterized in that, the RLC protocol data unit serial number that needs retransmission that receives described MAC entity sends, specifically comprises: receiving the sequence number of the RLC protocol data unit identified and delivered by the MAC entity; or, receiving the RLC protocol data unit data delivered by the MAC entity, and identifying the corresponding RLC protocol data unit sequence number according to the RLC protocol data unit data. 5. The method for retransmitting cross-carrier RLC layer data according to claim 4, wherein the RLC layer data of an unauthorized cell transmission failure is sent to the MAC entity, specifically comprising: Segmenting the RLC layer data that fails to be transmitted by the unlicensed cell according to the size of the MAC protocol data unit indicated by the MAC entity; re-encapsulate the RLC layer data that failed to be transmitted in the segmented unlicensed cell; delivering the encapsulated RLC layer data of the failed transmission of the unlicensed cell to the MAC entity. 6. A cross-carrier RLC layer data retransmission method, applied to a medium access control MAC entity, is characterized in that, comprising: An RLC retransmission indication sent to an RLC entity preparing to perform RLC retransmission when a target authorized cell with available resources is detected; Receiving the RLC layer data that the RLC entity sent according to the RLC retransmission indication that the transmission of the unauthorized cell failed; Retransmitting the RLC layer data that fails to be transmitted by the unlicensed cell by using available resources of the target authorized cell. 7. The cross-carrier RLC layer data retransmission method according to claim 6, wherein, before the RLC retransmission indication sent to the RLC entity preparing to carry out RLC retransmission, it also includes: When HARQ data retransmission failure is detected, the HARQ data retransmission failure indication and the sequence number of the RLC protocol data unit to be retransmitted are sent to the RLC entity. 8. The cross-carrier RLC layer data retransmission method according to claim 7, wherein the retransmission of hybrid automatic repeat request HARQ data is detected to fail, specifically comprising: When it is detected that the number of HARQ data retransmissions reaches the maximum number of retransmissions, the HARQ data retransmission fails; or, When it is detected that the HARQ data retransmission time exceeds the maximum retransmission delay, the HARQ data retransmission fails. 9. the cross-carrier RLC layer data retransmission method according to claim 8, is characterized in that, sends the RLC protocol data unit serial number that needs retransmission to described RLC entity, specifically comprises: Identify the corresponding RLC protocol data unit sequence number according to the retransmitted RLC layer data, and send the RLC protocol data unit sequence number to the RLC entity; or, The RLC protocol data unit data sent to the RLC entity, wherein the corresponding RLC protocol data unit sequence number can be identified according to the RLC protocol data unit data. 10. The cross-carrier RLC layer data retransmission method according to claim 9, wherein detecting a target authorized cell with available resources comprises: When it is detected that there are available resources in the authorized cell, determining the authorized cell where the first available resource is located as the target authorized cell; or Searching for a first authorized cell corresponding to an unauthorized cell that needs to retransmit RLC layer data according to a preset mapping relationship between an unauthorized cell and an authorized cell; When it is detected that there are available resources in the first authorized cell, it is determined that the first authorized cell is a target authorized cell. 11. A cross-carrier RLC layer data retransmission device, which is applied to a radio link control RLC entity, is characterized in that, comprising: The first receiving module is configured to receive an RLC retransmission indication sent when a medium access control MAC entity detects a target authorized cell with available resources; The first sending module is configured to send, to the MAC entity, the RLC layer data that fails to be transmitted by the unlicensed cell according to the RLC retransmission indication, so that the RLC layer data that fails to be transmitted by the unlicensed cell uses the target authorized cell available resources for retransmission. 12. The cross-carrier RLC layer data retransmission device according to claim 11, further comprising: The first processing module is configured to prepare for RLC retransmission when receiving the RLC status protocol data unit PDU; or, The second processing module is configured to prepare for RLC retransmission when receiving the hybrid automatic repeat request HARQ data retransmission failure indication sent by the MAC entity and the sequence number of the RLC protocol data unit that needs to be retransmitted. 13. The cross-carrier RLC layer data retransmission device according to claim 12, wherein the second processing module specifically comprises: The first receiving unit is configured to receive the HARQ data retransmission failure indication sent by the MAC entity when the number of HARQ data retransmissions reaches the maximum number of retransmissions; or, The second receiving unit is configured to receive the HARQ data retransmission failure indication sent by the MAC entity after the HARQ data retransmission time exceeds the maximum retransmission time delay. 14. The cross-carrier RLC layer data retransmission device according to claim 13, wherein the second processing module specifically comprises: The third receiving unit is configured to receive the sequence number of the RLC protocol data unit identified and delivered by the MAC entity; or, The fourth receiving unit is configured to receive the RLC protocol data unit data delivered by the MAC entity, and identify the corresponding RLC protocol data unit sequence number according to the RLC protocol data unit data. 15. The cross-carrier RLC layer data retransmission device according to claim 14, wherein the first sending module comprises: A segmentation unit, configured to segment the RLC layer data whose transmission failed in the unlicensed cell according to the size of the MAC protocol data unit indicated by the MAC entity; An encapsulation unit, configured to re-encapsulate RLC layer data that fails to be transmitted in the segmented unlicensed cell; The first sending unit is configured to deliver, to the MAC entity, the encapsulated RLC layer data that fails to be transmitted by an unlicensed cell. 16. A cross-carrier RLC layer data retransmission device, which is applied to a medium access control MAC entity, is characterized in that, comprising: The second sending module is used to send an RLC retransmission indication to an RLC entity preparing to perform RLC retransmission when a target authorized cell with available resources is detected; The second receiving module is configured to receive the RLC layer data sent by the RLC entity according to the RLC retransmission indication that the transmission of the unauthorized cell failed; A retransmission module, configured to use the available resources of the target authorized cell to retransmit the RLC layer data that failed to be transmitted by the unlicensed cell. 17. The cross-carrier RLC layer data retransmission device according to claim 16, further comprising: The third sending module is configured to send the HARQ data retransmission failure indication and the sequence number of the RLC protocol data unit to be retransmitted to the RLC entity when the HARQ data retransmission failure is detected. 18. The cross-carrier RLC layer data retransmission device according to claim 17, wherein the third sending module comprises: The first sending unit is configured to identify the corresponding RLC protocol data unit serial number according to the retransmitted RLC layer data, and send the RLC protocol data unit serial number to the RLC entity; or, The second sending unit is configured to send the RLC PDU data to the RLC entity, where the corresponding RLC PDU sequence number can be identified according to the RLC PDU data. 19. The cross-carrier RLC layer data retransmission device according to claim 18, further comprising: The first confirming module is configured to, when it is detected that there are available resources in the authorized cell, determine the authorized cell where the first available resource is located as the target authorized cell; or A search module, configured to search for a first authorized cell corresponding to an unlicensed cell that needs to retransmit RLC layer data according to a preset mapping relationship between an unlicensed cell and an authorized cell; The second confirming module is configured to determine that the first authorized cell is a target authorized cell when it is detected that there are available resources in the first authorized cell.