JP7122082B2 - Transmission device and transmission method - Google Patents

Description

The present invention relates to communication devices such as user equipment and base stations in wireless communication systems.

Currently, 3GPP (3rd Generation Partnership Project) is studying a next-generation system called 5G, which is a successor to LTE (Long Term Evolution)-Advanced, which is one of the 4th generation wireless communication systems. In 5G, mainly three use cases are assumed: eMBB (extended mobile broadband), mMTC (massive Machine Type Communication), and URLLC (Ultra Reliability and Low Latency Communication).

For example, URLLC aims to realize wireless communication with low delay and high reliability. As specific measures to achieve low delay in URLLC, introduction of Short TTI length (subframe length, also called subframe interval), shortening of control delay from packet generation to data transmission, etc. are being considered.

3GPP TS 36.321 V13.2.0 3GPP TS 36.322 V13.2.0 3GPP TS 36.323 V13.2.1 3GPP TS 36.300 V13.4.0

In existing LTE, a U-Plane (user plane) radio interface protocol between a base station (eNB) and a user equipment (UE) consists of Layer 1 (PHY) and Layer 2. Layer 2 includes MAC (Medium Access Control) (see Non-Patent Document 1), RLC (Radio Link Control) (see Non-Patent Document 2), and PDCP (Packet Data Convergence Protocol) (see Non-Patent Document 3). Consists of sublayers. The C-Plane is composed of the same protocol as the U-Plane and RRC, which is Layer 3.

In 3GPP standardization, 5G Layer 2 is being considered based on the above Layer 2 configuration in LTE, but in the current Layer 2 control in LTE, it takes time to calculate the header of data units such as RLC PDUs. , there is a problem that generation of data units such as RLC PDUs may not be completed within a specified time when assuming TTI and the like that are being considered for 5G. Note that this problem is a problem that can occur in various layers, not limited to RLC.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and it is an object of the present invention to provide a technique that enables a communication device used in a wireless communication system to shorten the time required to generate a data unit. .

In addition, as will be described in the second embodiment described later, the invention according to the second embodiment eliminates the delay caused by the order correction processing in a predetermined layer in the communication device of the wireless communication system. It is intended to

According to the disclosed technique, a value indicating the size of the first data unit is added to the first data unit, and a second data unit including the first data unit, the value, and other segmented first data units is generated. a generator that generates data units;
a transmitting unit configured to transmit the second data unit to a receiving device;
the second data unit has a header area;
The generating unit includes, in the header area in the second data unit, information corresponding to the segmented position in the original other first data unit before segmentation. provided.

According to the technology disclosed herein, a technology is provided that enables a communication device used in a wireless communication system to shorten the time required to generate a data unit.

1 is a configuration diagram of a radio communication system according to an embodiment of the present invention; FIG. FIG. 2 is a diagram showing a configuration example of Layer 2 in the user equipment 10 (base station 20); It is a figure which shows the example of a data flow of LTE. FIG. 4 is a diagram illustrating a configuration example of an RLC PDU; FIG. 2 is a diagram for explaining an example of transmission processing of RLC PDUs in conventional LTE; FIG. 4 is a diagram for explaining an example of RLC PDU transmission processing in 5G; FIG. 4 is a diagram for explaining RLC PDU generation processing in the first embodiment; FIG. 4 is a diagram for explaining RLC PDU generation processing in the first embodiment; FIG. 4 is a diagram for explaining RLC PDU generation processing in the first embodiment; FIG. 4 is a diagram for explaining RLC PDU generation processing in the first embodiment; FIG. 4 is a diagram for explaining Realtime processing/Non-realtime processing; FIG. 4 is a diagram for explaining Realtime processing/Non-realtime processing; It is a figure for demonstrating the modification in 1st Embodiment. It is a figure for demonstrating the modification in 1st Embodiment. It is a figure for demonstrating the subject corresponding to 2nd Embodiment. FIG. 10 is a diagram for explaining processing of the user equipment 10 (base station 20) in the second embodiment; It is a figure for demonstrating the modification in 2nd Embodiment. It is a figure for demonstrating the modification in 2nd Embodiment. It is a figure for demonstrating the modification in 2nd Embodiment. FIG. 13 is a diagram for explaining the operation when Dual Connectivity is applied in the modification of the second embodiment; 2 is a functional configuration diagram of the user device 10; FIG. (a) shows the whole, (b) shows an example of the layer 2 processing section 103 in the first embodiment, and (c) shows an example of the layer 2 processing section 103 in the second embodiment. 2 is a functional configuration diagram of a base station 20; FIG. (a) shows the whole, (b) shows an example of the layer 2 processing section 203 in the first embodiment, and (c) shows an example of the layer 2 processing section 203 in the second embodiment. 2 is a hardware configuration diagram of the user equipment 10 and the base station 20. FIG.

An embodiment (this embodiment) of the present invention will be described below with reference to the drawings. The embodiments described below are merely examples, and the embodiments to which the present invention is applied are not limited to the following embodiments.

It is assumed that the radio communication system of this embodiment supports at least the LTE communication scheme. Therefore, when the radio communication system operates, the existing technology defined by LTE can be used as appropriate. However, the existing technology is not limited to LTE. In addition, “LTE” used in this specification has a broad meaning including LTE-Advanced and LTE-Advanced and subsequent systems, unless otherwise specified. Also, the present invention is applicable to communication schemes other than LTE.

In addition, in the following first and second embodiments, terms such as MAC, RLC, and PDCP used in existing LTE are used, but this is for convenience, and similar to these Functions may be called by other names.

A "data unit" herein may also be referred to as a "packet", "frame", "datagram", or the like. Both PDUs and SDUs described below are examples of "data units."

Also, in the first and second embodiments described below, data units of specific layers are targeted, but these are examples, and the present invention will be described in the first and second embodiments. It is not limited to the layer that has been used, and can be applied to other layers.

(Overall system configuration)
FIG. 1 shows a configuration diagram of a radio communication system according to this embodiment (common to the first and second embodiments). The radio communication system according to the present embodiment includes user equipment 10 and base station 20, as shown in FIG. Although FIG. 1 shows one user equipment 10 and one base station 20, this is an example and there may be more than one of each. Also, the operations described below are basically described as the operations of the user equipment 10, but the base station 20 can also perform similar operations. In order to express this, hereinafter, descriptions such as “user equipment 10 (base station 20)” are used. The user equipment 10 and the base station 20 may be collectively referred to as "communication equipment".

Also, the first embodiment (including modifications), the second embodiment (including modifications), or the first embodiment (including modifications) and the second embodiment Both forms (including modifications) may be applied to sidelink communication in which user devices communicate directly without going through a base station.

(Configuration example of layer 2)
Regarding the processing in layer 2 that is focused on in this embodiment (common to the first and second embodiments), the user equipment 10 (base station 20) operates based on the operation of layer 2 defined in LTE. 2, the basic functional configuration of Layer 2 included in the user equipment 10 (base station 20) will be described first. Note that the PDCP sublayer (or PDCP layer) may also be referred to as a PDCP entity or a PDCP processing unit. An RLC sublayer (or RLC layer) may be referred to as an RLC entity or RLC processor. A MAC sublayer (or MAC layer) may also be referred to as a MAC entity or MAC processing unit.

<PDCP>
On the transmitting side indicated by Tx (eg, transmission from the user equipment 10 to the base station 20), the PDCP sublayer performs IP packet header compression processing (ROHC) and security processing (security), and the RLC sublayer receives PDCP PDUs. is passed. On the receiving side indicated by Rx, processes such as header restoration, deciphering, integrity check, etc. corresponding to the transmitting side are performed. Also, at the time of handover, packet loss is avoided by retransmitting unconfirmed user data on the transmitting side, and duplication detection and sequence correction are performed on the receiving side.

<RLC>
The RLC sublayer has three modes: AM (Acknowledged Mode), UM (Unacknowledged Mode), and TM (Transparent Mode). On the transmission side of RLC-AM/UM, based on the TB (transport block) size notified from the MAC layer, by performing segmentation and concatenation of PDCP PDU, the TB size for each TTI Generate the matching RLC PDU and pass it to the MAC sublayer. The receiving side reassembles the PDCP PDUs.

Also, in RLC-AM, ARQ control is implemented in which the transmitting side retransmits the RLC PDU based on an acknowledgment signal (STATUS PDU) from the receiving side. Also, at the receiving side of RLC-AM/UM, duplicate detection and order correction are further performed.

<MAC>
Shared channel resources are scheduled in the MAC sublayer. That is, in the downlink, the scheduler of the base station 20 determines which bearer's RLC PDU for which user equipment is to be multiplexed into the TB and transmitted. In the uplink, the scheduler of the base station 20 determines which user equipment is to transmit data on PUSCH, and determines which bearer's RLC PDU is multiplexed in the TB by the user equipment 10 . The MAC entity on the transmitting side and the MAC entity on the receiving side transmit the TB using HARQ, and the receiving side extracts the RLC PDU from the TB and passes it to the RLC entity.

FIG. 3 shows an example of data flow in PDCP, RLC, MAC, and PHY. As shown in FIG. 3, PDUs are passed from higher layers to lower layers on the transmitting side, and SDUs are passed from lower layers to higher layers on the receiving side.

The first embodiment and the second embodiment will be described in detail below.

(First embodiment)
<Problems of the first embodiment>
First, problems in the first embodiment will be described in detail with reference to FIGS.

As described above, in the RLC layer of the user equipment 10 (base station 20), data segmentation and data concatenation from the RLC SDU are performed on the transmission side based on the TB size notified from the MAC layer. generates an RLC PDU.

FIG. 4 shows an example of RLC PDUs (here, AMD PDUs, which are RLC-AM PDUs) (Non-Patent Document 2). D/C in the header means Data or Control and indicates whether this RLC PDU is Data PDU or Control PDU. RF is a Re-segmentation Flag and indicates whether this RLC PDU is an AMD PDU or an AMD PDU segment. P is a polling bit and indicates the presence or absence of a STATUS report request. FI is Frame Info and indicates whether the first/last bit of Data is the first/last of SDU. E is an Extension bit, and indicates which of the pair of E and LI or Data follows. SN is Sequence Number, which is a serial number assigned to each PDU.

LI is Length Indicator and indicates the boundary of RLC SDU in the data field (which may be called payload). That is, LI indicates the length (data size) of the corresponding RLC SDU in the data field. In the RLC layer on the transmission side, the user apparatus 10 (base station 20) uses the LI to recognize the boundaries of (concatenated) RLC SDUs in the RLC layer on the reception side when performing Concatenation. The SDU length is reported in the RLC header.

That is, in conventional LTE, RLC PDU generation in the RLC layer can only be performed after the actual resource allocation has been performed and the TB size has been determined. A more specific example will be described with reference to FIG. FIG. 5 shows an example of data transmission focused on the RLC layer from a user equipment in conventional LTE. As shown in FIG. 5 , when the user equipment receives a UL grant from the base station, the UE performs processing for the UL grant such as TB size determination (step S1), and performs RLC SDU condensation/segmentation (step S2). Subsequently, the user equipment performs RLC PDU header calculation processing (LI calculation, etc.) (step S3), and performs RLC PDU transmission processing (step S4). In the existing LTE, it is specified that the user equipment performs data transmission (PUSCH transmission) 4 ms (4 TTI) after receiving the UL grant.

Next, an example of data transmission from the user equipment when the TTI is shortened as envisioned in 5G will be described with reference to FIG. In the example of FIG. 6, it is assumed that data transmission (PUSCH transmission) is performed 1 ms after receiving the UL grant. As shown in FIG. 6, processing for UL grant (step S11), consumption/segmentation (step S12), RLC PDU header calculation processing (step S13), and RLC PDU transmission processing (step S14). It takes time, and there is a possibility that RLC PDU generation and transmission cannot be completed within the specified time.

That is, if the TTI is shortened in 5G and the bit rate is increased, there is a problem that data processing (RLC PDU generation) may not keep up. Improving the processing capability of the user equipment may solve this problem, but the user equipment becomes complicated and expensive, which is not a preferable solution.

<Details of processing in the first embodiment>
In order to solve the above problem, in the first embodiment, the RLC PDU format is changed from the existing RLC PDU format, and the length of the RLC SDU is set in an area other than the RLC PDU header (that is, in the payload ).

More specifically, when transmitting data, the user equipment 10 (base station 20) receives an RLC SDU from the PDCP layer in the RLC layer, regardless of whether the size of the RLC PDU has been determined. (ie, regardless of whether the TB size is determined), calculate the value of the LI field, which is the length (size) of the RLC SDU. Through such processing, the user equipment 10 (base station 20) calculates the value of the LI field offline before the TB size is determined (before receiving the UL grant in the case of the user equipment 10). can be done. As a result, the amount of calculation is reduced when generating RLC PDUs, so that, for example, in the example shown in FIG. 6, it is possible to perform data transmission within a specified time while suppressing complication of the device.

The insertion position of the LI field may be any position other than the RLC header, for example, just before the RLC SDU. Also, the LI field may be inserted immediately after the RLC SDU.

An example of RLC PDU generation processing in the user equipment 10 will be described with reference to FIG. In the example shown in FIG. 7, each time an RLC SDU is generated, the user equipment 10 calculates the value of the LI field corresponding to that RLC SDU and appends the value of the LI field to that RLC SDU. The example of FIG. 7 shows that the values of the LI field of the RLC SDU are calculated and added in the order indicated by 1, 2, and 3. FIG. Note that the LI field in which the value of the LI field is set may be called "LI".

In the example of FIG. 7, for example, the RLC SDU (LI + RLC SDU) to which the LI is added is stored in a buffer, and after the length of the RLC PDU (the payload length A of the RLC PDU) is determined, each "LI + RLC SDU ” are concatenated. The example of FIG. 7 shows an example in which the payload length A of the RLC PDU is equal to the concatenated length of exactly three "LI+RLC SDUs". However, more generally, the length of the payload of the RLC PDU does not match the length of the concatenation of an integer number of "LI+RLC SDUs", e.g. Part (not including LI), 2, 3 "LI+RLC SDU" and part of 4 "LI+RLC SDU" (including LI) are stored in the payload of the RLC PDU.

In the above example, the LI and the RLC SDU are concatenated in advance (before the length of the payload of the RLC PDU is determined), but the LI and the RLC SDU are concatenated after the length of the RLC PDU is determined. It is also possible to

Alternatively, "LI+RLC SDU" may be concatenated in advance (before the payload length of the RLC PDU is determined). An example of processing in this case will be described with reference to FIG. In this case, the user apparatus 10 (base station 20) calculates the LI each time an RLC SDU is generated, adds the LI to the beginning of the RLC SDU, and replaces the "LI+RLC SDU" with the immediately preceding "LI+RLC SDU". The concatenated data (bit string) is stored in a buffer. Then, when the length of the payload of the RLC PDU is determined, the user equipment 10 (base station 20) stores the bit string in the payload of the RLC PDU.

In the example of FIG. 9 , the user equipment 10 (base station 20) performs part of the “LI+RLC SDU” indicated by 1, “LI+RLC SDU” indicated by 2 and 3, and 4 is extracted from the bit string stored in the buffer and stored in the payload of the RLC PDU. The above cutting process may be called segmentation.

That is, conventional Concatenation processing could only be performed after TB size determination, but by using the RLC PDU format according to the present embodiment, Concatenation can also be performed offline (before TB size determination). becomes.

Concatenation may thus be implemented at the PDCP layer. The process in this case corresponds to, for example, the process in which "RLC SDU" in FIG. 9 is replaced with "PDCP PDU".

In the above example, the LI is added to the beginning (just before) of the RLC SDU, but as shown in FIG. 10, the LI may be added to the end (immediately after) of the RLC SDU. Note that the length of the LI field may be a predetermined length.

In the user equipment 10 (base station 20), processing that can be performed only after the TB is determined is called realtime processing (RT processing), and processing that can be performed before the TB size is determined is called non-realtime processing (RT processing).

FIG. 11 shows the division of NR processing and RT processing in layer 2 of conventional LTE, and FIG. 12 shows the division (example) of NR processing and RT processing in layer 2 in this embodiment. As shown in FIG. 11, in conventional LTE, Concatenation and Segmentation can only be performed after TB determination. On the other hand, as shown in FIG. 12, in this embodiment, as already described, the Concatenation process can be performed before the TB size is determined.

<Regarding processing on the receiving side>
Processing on the receiving side of the RLC layer in this embodiment will be described. When the user equipment 10 (base station 20) receives an RLC PDU, if the SNs in the RLC header are continuous, the LI (RLC SDU length) in the payload portion of the PDU is observed, and the corresponding RLC SDU is Get the data (byte segment) and reconstruct the RLC SDU. For example, when the user equipment 10 (base station 20) receives the RLC PDU shown in FIG. Obtain the indicated RLC SDU, obtain the RLC SDU indicated by 2 based on the next LI, and further obtain the RLC SDU indicated by 3 based on the next LI.

<Other examples>
Only when user equipment 10 receives from the network (that is, base station 20) instruction information instructing to apply the functions described in the first embodiment (including modifications described later), the first The function described in the embodiment (including the modification) may be applied, or the function may always be applied.

Also, the functions described in the first embodiment (including modifications) may be applied only to RLC-AM in the user equipment 10 (base station 20).

Also, the functions described in the first embodiment (including modifications) may be applied only to specific user devices. In this case, for example, the user equipment supporting the function notifies the NW (base station 20) of capability information (capability) indicating that the function is supported. Also, the specific user device is, for example, a user device that provides a specific service. The particular service is, for example, a service with a short TTI, or a service with an expected throughput (Tput) exceeding a predetermined value, or both. Further, the specific service may be a service that sets a specific bearer (eg, Best effort), or a broadband communication service (eg, CA and/or DC, etc. are set). There may be.

In addition, the functions described in the first embodiment (including modifications) are for downlink communication, uplink communication, and sidelink communication in which direct communication is performed between user devices without going through a base station. For each, it may be determined whether or not it applies. That is, whether or not the functions described in the first embodiment (including modifications) are applied may differ between downlink communication, uplink communication, and sidelink communication. .

<Modification of First Embodiment>
Modifications of the first embodiment will be described below. As already explained, in the first embodiment, the RLC SDU length (LI) is moved to a non-RLC header area. In this case, the following problem may occur on the receiving side. It should be noted that the effect of shortening the data unit generation time can be obtained according to the first embodiment even if the following modified example is not implemented.

Normally, in-sequence delivery is guaranteed in the RLC layer (RLC-AM is assumed here) (SN is received without omission), so if there is an omission in SN on the receiving side (RLC on the way PDU has not been received), do not construct an RLC SDU from subsequent RLC PDUs until the missing part is received. That is, the receiving side keeps requesting the sending side to retransmit the missing part.

On the other hand, in a case (RLC re-establishment) where the RLC layer is once reestablished (initialized/flushed) as in handover or reconnection, the received data is out-of-order on the receiving side. Even if there is, if reconstruction is possible, the RLC SDU is reconstructed from the RLC PDU, and the RLC SDU is sent to the PDCP layer. As a result, the amount of data retransmitted from the transmitting side after handover/reconnection can be suppressed, and resource utilization efficiency can be improved.

In the conventional RLC PDU format, even if there is an omission in the RLC PDU, the header has LI (there is information on the boundary of the RLC SDU), so it is possible to reconstruct the RLC SDU from the payload as much as possible. be. An example of this case is shown on the left side of FIG. As shown in FIG. 13 (left side), even if there is an omission in the RLC PDU, the receiving side grasps the data position of the RLC SDU indicated by 2 in the payload from the LI information in the RLC header of the received RLC PDU. Therefore, the RLC SDU indicated by 2 can be obtained.

On the other hand, in the format in the first embodiment, if the RLC PDU containing the LI is missing, it is not possible to know where the RLC SDU boundary is in the payload, and the RLC SDU is reconstructed during RLC re-establishment. Can not do it. An example of this case is shown on the right side of FIG. As shown in FIG. 13 (right side), the receiving side does not receive the RLC PDU including the LI of the RLC SDU indicated by 1, but receives the RLC PDU including the LI of the RLC SDU indicated by 2. In this case, since the receiving side cannot grasp the RLC SDU boundary (the starting position of the RLC SDU indicated by 2) in the payload of the received RLC PDU, even if the RLC SDU indicated by 2 exists in the received RLC PDU, , unable to get it.

Therefore, in this modified example, the RLC SDU boundary information is notified in the RLC PDU. More specifically, as shown in FIG. 14, the user apparatus 10 (base station 20) generates the RLC PDU from the end of the RLC header to the start (octet) of the LI field closest to the RLC header. ) is included in the RLC header. Further, when the user equipment 10 (base station 20) generates the RLC PDU, the length (Length offset ) may be included in the RLC header. In either case, the Length offset is information corresponding to the position of the RLC SDU.

On the receiving side, the user equipment 10 (base station 20) can grasp where in the payload data (byte segments) forming the RLC SDU is located, even if there is an omission of the RLC PDU. For example, in the case on the right side of FIG. 13, the receiving user equipment 10 (base station 20) can acquire the RLC SDU indicated by 2 based on the length offset in the header of the received RLC PDU.

<Regarding the handling of special cases in the modified example>
When the data (byte segment) at the beginning of the payload corresponds to the beginning (octet) of the LI field, that is, when the beginning of the "LI + RLC SDU" starts from the beginning of the payload (data field) of the RLC PDU (example: Figure In 7), Length offset may be set to 0, or the Length offset field itself may not be inserted into the RLC header. Also, a flag indicating whether or not there is a Length offset field may be inserted into the RLC header.

If there is no boundary between RLC SDUs in the RLC payload, for example, Length offset=payload length+1 may be set, or the Length offset field itself may not be inserted into the RLC header. Also, a flag indicating whether or not there is a Length offset field may be inserted into the RLC header.

(Second embodiment)
A second embodiment will be described below. The functions of the second embodiment described below may be applied after applying the functions of the first embodiment described above, or may be applied independently of the functions of the first embodiment. , for example, for conventional LTE Layer 2 functionality.

<Problem in Second Embodiment>
As already explained, the RLC layer usually guarantees in-sequence delivery (transfer according to the order of the SN of the RLC PDU), so if there is a missing RLC PDU, an out-of-order RLC PDU (RLC PDU with new SN but previously received) is buffered at the RLC layer.

Therefore, when the missing RLC PDU is received on the receiving side, it is finally possible to assemble the RLC SDU at that time and perform reception processing (decryption processing, etc.) of the PDCP layer. However, since the processing of the PDCP layer is relatively heavy processing, if many RLC PDUs are waiting for reordering, data cannot be sent to the upper layer within a predetermined time, and E2E (end to end) There is a problem that the delay increases. Namely. In conventional LTE, there is a problem that an additional U-plane delay occurs due to the reordering (order correction) delay of the RLC layer. The technology according to the second embodiment is a technology for solving this problem, and the technology eliminates the delay caused by order correction processing in a predetermined layer in a communication device of a wireless communication system. This technology aims to enable

FIG. 15 shows an example of a situation in which this problem occurs in conventional LTE. In the example shown in FIG. 15, the RLC layer on the receiving side has not received the RLC PDU of SN=1, and RLC PDUs of subsequent SNs are buffered.

<Regarding processing contents in the second embodiment>
In order to solve the above problem, in the second embodiment, even if the RLC re-establishment procedure is not activated, the user equipment 10 (base station 20) on the receiving side receives in the RLC layer From the RLC PDU, reconstruct a reconstructable RLC SDU (or part thereof). The reconstruction method itself is, for example, the method on the left side of FIG. 13 (conventional LTE), or the method of using the Length offset when the Length offset of FIG. 14 is provided (first embodiment). be able to.

An example will be described with reference to FIG. In the example shown in FIG. 16, the receiving-side user equipment 10 (base station 20) receives RLC PDUs with SN=2 and 3 without receiving the RLC PDU with SN=1. In the second embodiment, regardless of whether the RLC re-establishment procedure is activated, the user equipment 10 (or the base station 20) receives the RLC PDU of SN=2 without receiving the RLC PDU of SN=1. , 3 RLC PDUs and pass them to the PDCP layer. After that, when the user equipment 10 (or the base station 20) receives the RLC PDU with SN=1, it acquires the RLC SDU from the RLC PDU with SN=1 and passes it to the PDCP layer.

The RLC SDU passed to the PDCP layer may be the entire RLC SDU, or may be a part of the RLC SDU obtained from the beginning (or end) of the payload of the RLC PDU (example: FIG. 8 , Fig. 9).

By the above-described processing, for data of RLC PDUs waiting for reordering (eg, RLC PDUs with SN=2 and 3 in FIG. 16), missing RLC PDUs (eg, RLC PDUs with SN=1 in FIG. 16) are received. The PDCP layer deciphering process can be performed even before the PDCP layer is received, and the PDCP SDU can be sent to the upper layer without delay when the missing RLC PDU is received. That is, it is possible to eliminate the delay caused by the order correction processing.

<Modification of Second Embodiment>
In the above-described process, the PDCP layer can determine whether the out-of-order PDCP PDU (or part thereof) is still being retransmitted by the RLC/MAC layer or has already been discarded on the transmitting side. First, on the receiving side, there is a problem that detection of packet loss on the transmitting side (in the upper layer) may be delayed (degeneration of TCP window is delayed).

This problem will be described with reference to FIGS. 17 and 18. FIG. FIG. 17 shows the transmission/reception operations of the PDCP layer and the RLC layer in conventional LTE, and FIG. 18 shows the transmission/reception operations of the PDCP layer and the RLC layer when performing the processing of the above-described second embodiment.

As shown in FIG. 17, in conventional LTE, the PDCP PDU with SN = 0 is discarded in the PDCP layer on the transmitting side, and the PDCP PDUs with SN = 1 and 2 are received by the RLC PDUs with SN = 0, 1 and 2. sent to the side. The RLC layer on the receiving side guarantees the order of the SNs of the RLC PDUs and transfers the RLC SDUs to the PDCP layer. In the example of FIG. 17, the RLC layer on the receiving side receives all RLC PDUs in the order in which they were transmitted by the transmitting side, and passes the acquired RLC SDUs to the PDCP layer. Although the PDCP layer expected the next PDCP PDU with SN=0, it is determined that the PDCP PDU with SN=1 was received without receiving the PDCP PDU with SN=0. That is, in this case, it is possible to implicitly determine in the PDCP layer on the receiving side that "the PDCP PDU with PDCP SN=0 was discarded without being transmitted wirelessly on the transmitting side".

A case of performing processing according to the second embodiment will be described with reference to FIG. In case 1 of FIG. 18, the PDCP PDU with SN=0 is discarded in the PDCP layer of the transmitting side, and the PDCP PDU with SN=1 is transmitted to the receiving side by the RLC PDU with SN=0. The receiving side receives an RLC PDU with SN=0, and receives a PDCP PDU with SN=1 instead of expecting a PDCP PDU with SN=0 at the PDCP layer.

In case 2 shown in FIG. 18 , the transmitting side cannot confirm the delivery of the transmitted RLC PDU with SN=0 (because the RLC PDU with SN=0 has not reached the receiving side). PDU is being retransmitted. On the other hand, the RLC PDU with SN=1 reaches the receiving side. The receiving side does not receive the RLC PDU with SN = 0, but in the second embodiment, acquires the RLC SDU (PDCP PDU with SN = 1) from the previously received RLC PDU with SN = 1, Pass to PDCP layer.

In the above situation, the PDCP layer on the receiving side cannot distinguish between Case 1 and Case 2, and cannot determine whether it has been discarded by the transmitting side or is being retransmitted over the air. Therefore, there is a problem that detection of packet loss on the transmitting side (at the higher layer) may be delayed on the receiving side.

<Details of processing in the modified example of the second embodiment>
Therefore, in the modified example of the second embodiment, when the PDCP PDU (or part thereof) is sent from the RLC layer to the PDCP layer in the user equipment 10 (base station 20) on the receiving side, the RLC layer Notifies the PDCP layer whether or not there is still data expected to be received. "When sending a PDCP PDU (or part thereof) from the RLC layer to the PDCP layer" means, for example, whether or not there is still data expected to be received together with the PDCP PDU (or part thereof). It is to notify the information to be shown.

FIG. 19 shows the operation of the modified example in case 1 and case 2 shown in FIG. As shown in FIG. 19, in case 1, the user equipment 10 (base station 20) on the receiving side receives the RLC PDUs in the correct order in the RLC layer. = PDCP PDU) from the RLC layer to the PDCP layer, the PDCP layer is notified of information indicating that the RLC PDU carrying the RLC SDU was received in the correct order. In the PDCP layer, this notification detects the missing PDCP PDU with SN=0, but it can be determined that the PDU has been discarded on the transmitting side.

In case 2, the user equipment 10 (base station 20) on the receiving side detects that the RLC PDU with SN=0 is missing in the RLC layer. Then, when the receiving-side user equipment 10 (base station 20) passes the RLC SDU (=PDCP PDU) acquired from the received RLC PDU with SN=1 from the RLC layer to the PDCP layer, the old data being retransmitted is It notifies the PDCP layer of information indicating that there is. The information may be information indicating that the RLC PDU with SN=0 has not been received. In the PDCP layer, it can be determined from the notification that the PDCP PDU with SN=0 is still being wirelessly transmitted.

The above-described notification in the modified example (for convenience, this will be referred to as reception status notification) enables the PDCP layer on the receiving side to quickly detect packet loss on the transmitting side.

The reception status notification may be performed one by one when data (PDCP PDU) is sent from the RLC layer (eg PDCP PDU unit), or only when there is data expected to be received (or when there is no data). may be

At the time of notification of the reception status, the status of RLC PDUs waiting for reordering in the RLC layer may also be reported. That is, in case 2 of FIG. 19, the status of the RLC PDU with SN=1 is reported. The contents of the report include, for example, the total amount of RLC PDU data waiting for reordering, the number of PDUs, the feedback status of RLC ACK/NACK, the oldest SN among the RLC PDUs waiting for reordering, and the waiting time for reordering. All of these may be reported, or some (one or more) of them may be reported.

Alternatively, information on RLC PDUs missing in the RLC layer may be reported together with the reception status notification. In the example of case 2 in FIG. 19, the information about the RLC PDU with SN=0 is reported. The contents of the report are, for example, the number of missing RLC PDUs, the feedback status of RLC ACK/NACK, and the like. All of these may be reported, or some (one or more) of them may be reported.

Further, when RLC (/PDCP) is re-established in the receiving-side user equipment 10 (base station 20), the reception status notification may not be performed. This is because in this case, the RLC layer would send an out-of-order RLC SDU to the PDCP layer.

Note that, in the present embodiment, as in the existing LTE, security processing using a COUNT value (Hyper frame number + PDCP SN) is performed in the PDCP layer. A Hyper frame number (HFN) is incremented each time the PDCP SN goes around. The receiving side estimates the HFN from the PDCP SN included in the header of the received PDCP PDU.

Here, the user equipment 10 (base station 20) on the receiving side may perform the reception status notification only when the SN length in the header of the PDCP PDU is equal to or greater than a predetermined value.

Specifically, for example, when the SN length is 15 bits or more or 18 bits or more adopted in LTE, or when the COUNT value (32 bits) is included in the header, the reception status notification is performed. may be

As described above, in the PDCP layer, the PDCP Hyper Frame Number used in the deciphering process of the PDCP PDU, while looking at the SN of the received PDCP PDU, it is determined whether to increment, but in the second embodiment , the PDCP layer may receive a larger SN than the SN expected to receive, so if the SN is too short, the PDCP layer may estimate an incorrect Hyper Frame Number. Therefore, the reception status notification may be performed only when the SN length in the header of the PDCP PDU is equal to or greater than a predetermined value. By performing such a limitation, it is possible to reduce the possibility of estimating an erroneous Hyper Frame Number in the PDCP layer.

<Other examples>
The user equipment 10 performs the second embodiment only when receiving instruction information instructing to apply the functions described in the second embodiment (including the modification) from the network (that is, the base station 20). (including modifications) may be applied, or the function may always be applied.

Also, the functions described in the second embodiment (including modifications) may be applied only to RLC-AM in the user equipment 10 (base station 20).

Also, the functions described in the second embodiment (including modifications) may be applied only to specific user devices. In this case, for example, the user equipment supporting the function notifies the NW (base station 20) of capability information (capability) indicating that the function is supported. Also, the specific user device is, for example, a user device that provides a specific service. The particular service is, for example, a service with a short TTI, or a service with an expected throughput (Tput) exceeding a predetermined value, or both. Further, the specific service may be a service that sets a specific bearer (eg, Best effort), or a broadband communication service (eg, CA and/or DC, etc. are set). There may be.

Further, as in the case of applying the Dual Connectivity Split bearer (see Non-Patent Document 4) illustrated in FIG. 20 , when a plurality of RLC entities are associated with one PDCP entity, the user equipment 10 ( The PDCP layer in the base station 20) may expect an indication (reception status notification) from only one of them, or may expect an indication from both. Note that the configuration shown in FIG. 20 shows, for example, the configuration of Layer 2 of the user equipment 10 that performs Split bearer of Dual Connectivity in UL. In this case, the user equipment 10 is provided with a MAC entity, RLC entity, and PDCP entity for MeNB, and a MAC entity, RLC entity, and PDCP entity for SeNB. Further, the configuration shown in FIG. 20 may be interpreted as showing the configuration of layer 2 in, for example, the base station 20 (here, consisting of two MeNB and SeNB) performing Split bearer of Dual Connectivity in DL. .

In addition, the functions described in the second embodiment (including modifications) are for downlink communication, uplink communication, and sidelink communication in which direct communication is performed between user devices without going through a base station. For each, it may be determined whether or not it applies. That is, whether or not the functions described in the second embodiment (including modifications) are applied may differ between downlink communication, uplink communication, and sidelink communication. .

(Device configuration)
A functional configuration example of the user equipment 10 and the base station 20 that perform the operations of the first and second embodiments described above will be described. Each of the user equipment 10 and the base station 20 may have only the functions of the first embodiment (including modifications) with respect to layer 2, or may have the functions of the second embodiment (including modifications). It may have only the function, or may include both the function of the first embodiment (including the modification) and the function of the second embodiment (including the modification). Hereinafter, unless otherwise specified, the user equipment 10 and the base station 20 each have both the functions of the first embodiment (including modifications) and the functions of the second embodiment (including modifications). It is assumed to contain

<User device>
(a) of FIG. 21 is a diagram showing an example of the functional configuration of the user device 10 . As shown in FIG. 21( a ), the user equipment 10 has a signal transmitting section 101 , a signal receiving section 102 , a layer 2 processing section 103 and an upper layer processing section 104 . The functional configuration shown in FIG. 21(a) is merely an example. As long as the operation according to the present embodiment can be executed, the functional division and the name of the functional unit may be arbitrary. For example, the layer 2 processing unit 103 may be divided into the receiving side and the transmitting side, the layer 2 processing unit on the transmitting side may be included in the signal transmitting unit 101 , and the layer 2 processing unit on the receiving side may be included in the signal receiving unit 102 .

The signal transmission unit 101 corresponds to a functional unit of the physical layer on the transmission side, and is configured to wirelessly transmit the signal passed from the layer 2 processing unit 103 . The signal receiving unit 102 corresponds to a functional unit of the physical layer on the receiving side, and is configured to wirelessly receive various signals and pass the received signals to the layer 2 processing unit 103 .

The layer 2 processing unit 103 has the layer 2 configuration described with reference to FIG. It has the processing function described in (including modified examples).

Further, for example, in correspondence with the processing function described in the first embodiment (including the modification), as shown in (b), the layer 2 processing unit 103 transmits the first a first generation unit 113 that generates a data unit; a value indicating the size of the first data unit is added to the first data unit generated by the first generation unit 113; and a second generator 123 for generating a second data unit including a payload having a payload.

Further, for example, in correspondence with the processing function described in the second embodiment (including the modification), as shown in (c), the layer 2 processing unit 103 receives the sequence A first layer processing unit 133 that performs processing on a first data unit having a number, and a second layer processing unit 143 that performs processing on a second data unit acquired from the first data unit. Layer processing section 133 acquires the second data unit from the received first data unit, and when passing the second data unit to second layer processing section 143, the unreceived first data unit expected to be received. It may be configured to notify the second layer processing unit 143 whether or not there is a data unit.

The upper layer processing unit 104 is configured to process layers higher than layer 2 . The upper layer processing unit 104 is configured to execute, for example, IP packet transmission (generation)/reception processing and RRC processing as processing in the C-plane.

<Base station 20>
(a) of FIG. 22 is a diagram showing an example of the functional configuration of the base station 20 . As shown in FIG. 22( a ), base station 20 has signal transmitting section 201 , signal receiving section 202 , layer 2 processing section 203 and higher layer processing section 204 . The functional configuration shown in FIG. 22(a) is merely an example. As long as the operation according to the present embodiment can be executed, the functional division and the name of the functional unit may be arbitrary. For example, the layer 2 processing unit 203 may be divided into the receiving side and the transmitting side, the layer 2 processing unit on the transmitting side may be included in the signal transmitting unit 201 , and the layer 2 processing unit on the receiving side may be included in the signal receiving unit 202 .

The signal transmission unit 201 corresponds to a functional unit of the physical layer on the transmission side, and is configured to wirelessly transmit the signal passed from the layer 2 processing unit 203 . The signal receiving unit 202 corresponds to a functional unit of the physical layer on the receiving side, and is configured to wirelessly receive various signals and pass the received signals to the layer 2 processing unit 203 .

The layer 2 processing unit 203 has the layer 2 configuration described with reference to FIG. It has the processing function described in (including modified examples).

Also, for example, in correspondence with the processing function described in the first embodiment (including the modification), as shown in (b), the layer 2 processing unit 203 transmits the first a first generation unit 213 that generates a data unit; a value indicating the size of the first data unit is added to the first data unit generated by the first generation unit 213; and a second generator 223 for generating a second data unit including a payload having a payload.

Also, for example, in correspondence with the processing functions described in the second embodiment (including the modification), as shown in (c), the layer 2 processing unit 203 receives the sequence A first layer processing unit 233 that performs processing on a first data unit having a number, and a second layer processing unit 243 that performs processing on a second data unit acquired from the first data unit. The layer processing unit 233 acquires the second data unit from the received first data unit, and when passing the second data unit to the second layer processing unit 243, the unreceived first data unit expected to be received. It may be configured to notify the second layer processing section 243 whether or not there is a data unit.

The upper layer processing unit 204 is configured to process layers higher than layer 2 . The upper layer processing unit 204 is configured to execute, for example, IP packet transmission (generation)/reception processing and RRC processing as processing in the C-plane.

<Hardware configuration>
The block diagrams (FIGS. 21 and 22) used to describe the above embodiments show blocks in units of functions. These functional blocks (components) are implemented by any combination of hardware and/or software. Further, means for realizing each functional block is not particularly limited. That is, each functional block may be realized by one device in which multiple elements are physically and/or logically combined, or may be realized by two or more devices that are physically and/or logically separated. and/or may be indirectly (eg, wired and/or wireless) connected and implemented by these multiple devices.

Also, for example, both the user equipment 10 and the base station 20 according to the embodiment of the present invention may function as a computer that performs processing according to the present embodiment. FIG. 23 is a diagram showing an example of the hardware configuration of user equipment 10 and base station 20 according to the present embodiment. Each of the user device 10 and the base station 20 described above may be physically configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like. good.

Note that in the following description, the term "apparatus" can be read as a circuit, device, unit, or the like. The hardware configuration of the user equipment 10 and the base station 20 may be configured to include one or more of each device indicated by 1001 to 1006 shown in the figure, or may be configured without some devices. may

Each function in the user device 10 and the base station 20 is performed by loading predetermined software (programs) on hardware such as the processor 1001 and the memory 1002, the processor 1001 performs calculations, communication by the communication device 1004, memory 1002 and by controlling reading and/or writing of data in the storage 1003 .

The processor 1001, for example, operates an operating system to control the entire computer. The processor 1001 may be configured with a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic device, registers, and the like.

The processor 1001 also reads programs (program codes), software modules, or data from the storage 1003 and/or the communication device 1004 to the memory 1002, and executes various processes according to them. As the program, a program that causes a computer to execute at least part of the operations described in the above embodiments is used. For example, the signal transmission unit 101 , the signal reception unit 102 , the layer 2 processing unit 103 , and the upper layer processing unit 104 of the user equipment 10 may be stored in the memory 1002 and implemented by a control program running on the processor 1001 . Signal transmitting section 201 , signal receiving section 202 , layer 2 processing section 203 , and upper layer processing section 204 of base station 20 may be stored in memory 1002 and realized by a control program running on processor 1001 . Although it has been described that the above-described various processes are executed by one processor 1001, they may be executed by two or more processors 1001 simultaneously or sequentially. Processor 1001 may be implemented with one or more chips. Note that the program may be transmitted from a network via an electric communication line.

The memory 1002 is a computer-readable recording medium, and is composed of at least one of, for example, ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), RAM (Random Access Memory), and the like. may be The memory 1002 may also be called a register, cache, main memory (main storage device), or the like. The memory 1002 can store executable programs (program code), software modules, etc. to perform processing according to one embodiment of the present invention.

The storage 1003 is a computer-readable recording medium, for example, an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (for example, a compact disk, a digital versatile disk, a Blu-ray disk), smart card, flash memory (eg, card, stick, key drive), floppy disk, magnetic strip, and/or the like. Storage 1003 may also be called an auxiliary storage device. The storage medium described above may be, for example, a database, server, or other suitable medium including memory 1002 and/or storage 1003 .

The communication device 1004 is hardware (transmitting/receiving device) for communicating between computers via a wired and/or wireless network, and is also called a network device, network controller, network card, communication module, or the like. For example, the signal transmission unit 101 and the signal reception unit 102 of the user device 10 may be implemented by the communication device 1004 . Also, the signal transmission unit 201 and the signal reception unit 202 of the base station 20 may be realized by the communication device 1004 .

The input device 1005 is an input device (for example, keyboard, mouse, microphone, switch, button, sensor, etc.) that receives input from the outside. The output device 1006 is an output device (eg, display, speaker, LED lamp, etc.) that outputs to the outside. Note that the input device 1005 and the output device 1006 may be integrated (for example, a touch panel).

Devices such as the processor 1001 and the memory 1002 are also connected by a bus 1007 for communicating information. The bus 1007 may be composed of a single bus, or may be composed of different buses between devices.

In addition, the user equipment 10 and the base station 20 each include a microprocessor, a digital signal processor (DSP), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), an FPGA (Field Programmable Gate) device such as a It may be configured including hardware, and part or all of each functional block may be realized by the hardware. For example, processor 1001 may be implemented with at least one of these hardware.

(Summary of embodiment)
As described above, according to the present embodiment, a communication device used in a wireless communication system includes a first generation unit that generates a first data unit to be transmitted to another communication device; adding a value indicating the size of the first data unit to the first data unit generated by the first generation unit to generate a second data unit including a payload having the first data unit and the value; and a transmitter for transmitting said second data unit to said other communication device. With this configuration, it is possible to shorten the time required to generate a data unit in a communication device used in a wireless communication system.

The second generator may generate the second data unit by concatenating a plurality of data having the first data unit and a value indicating the size of the first data unit. With this configuration, the process of generating the second data unit can be performed quickly.

The size of the second data unit is a size determined based on radio resources available in the transmission unit, and the second generation unit performs the concatenation before the size of the second data unit is determined. It may be executed. With this configuration, concatenation can be executed by non-realtime processing.

The second data unit has a header area, and the second generator includes information corresponding to a predetermined first data unit position in the payload in the header area of the second data unit. may be With this configuration, even if there is no information for determining the position of the predetermined first data unit in the payload, the position of the predetermined first data unit can be grasped.

Further, according to the present embodiment, there is provided a transmission method executed by a communication device used in a wireless communication system, comprising: a first generation step of generating a first data unit to be transmitted to another communication device; a second generation of adding a value indicating the size of the first data unit to the first data unit generated by the first generation step to generate a second data unit including a payload having the first data unit and the value; and a transmitting step of transmitting said second data unit to said other communication device. With this configuration, it is possible to shorten the time required to generate a data unit in a communication device used in a wireless communication system.

Further, according to the present embodiment, there is provided a communication device used in a wireless communication system, wherein the receiving unit receives a first data unit having a sequence number from another communication device, and the receiving unit receives the sequence Even if the first data units are not received in the numerical order, the second data unit is acquired from the received first data unit, and the processing for acquiring upper layer data from the second data unit (e.g. : a layer 2 processing unit that executes anonymization processing). With this configuration, it is possible to eliminate delay caused by order correction processing in a predetermined layer in a communication apparatus of a wireless communication system.

The layer 2 processing unit has a first layer processing unit that executes processing on the first data unit and a second layer processing unit that executes processing on the second data unit, and the first layer processing unit acquires the second data unit from the received first data unit and passes the second data unit to the second layer processing unit, an unreceived first data unit expected to be received; The second layer processing unit may be notified of whether or not there is a With this configuration, the communication device can determine whether the second data unit has been discarded at the transmitting end or is being retransmitted wirelessly.

(Supplement to the embodiment)
Although the embodiments of the present invention have been described above, the disclosed invention is not limited to such embodiments, and those skilled in the art can understand various modifications, modifications, alternatives, replacements, and the like. be. Although specific numerical examples have been used to facilitate understanding of the invention, these numerical values are merely examples and any appropriate values may be used unless otherwise specified. The division of items in the above description is not essential to the present invention, and the items described in two or more items may be used in combination as necessary, and the items described in one item may be used in another item. may apply (unless inconsistent) to the matters set forth in Boundaries of functional or processing units in functional block diagrams do not necessarily correspond to boundaries of physical components. The operations of a plurality of functional units may be physically performed by one component, or the operations of one functional unit may be physically performed by a plurality of components. As for the processing procedures described in the embodiments, the processing order may be changed as long as there is no contradiction. Although the user equipment 10 and the base station 20 have been described using functional block diagrams for convenience of explanation of processing, such equipment may be implemented in hardware, software, or a combination thereof. The software operated by the processor possessed by the user equipment 10 according to the embodiment of the present invention and the software operated by the processor possessed by the base station 20 according to the embodiment of the present invention are respectively a random access memory (RAM), a flash memory, a read-only It may be stored in memory (ROM), EPROM, EEPROM, register, hard disk (HDD), removable disk, CD-ROM, database, server, or any other appropriate storage medium.

Also, the notification of information is not limited to the aspects/embodiments described herein, and may be performed in other ways. For example, the notification of information includes physical layer signaling (e.g., DCI (Downlink Control Information), UCI (Uplink Control Information)), higher layer signaling (e.g., RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, It may be implemented by broadcast information (MIB (Master Information Block), SIB (System Information Block))), other signals, or a combination thereof. The RRC signaling may also be referred to as an RRC message, such as an RRC Connection Setup message, an RRC Connection Reconfiguration message, and the like.

Each aspect/embodiment described herein includes Long Term Evolution (LTE), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G, 5G, FRA (Future Radio Access), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, UWB (Ultra-WideBand), It may be applied to systems utilizing Bluetooth®, other suitable systems, and/or advanced next generation systems based thereon.

The procedures, sequences, flow charts, etc. of each aspect/embodiment described herein may be interchanged so long as there is no inconsistency. For example, the methods described herein present elements of the various steps in a sample order, and are not limited to the specific order presented.

Certain operations referred to herein as being performed by the base station 20 may in some cases be performed by its upper nodes. In a network of one or more network nodes with a base station 20, various operations performed for communication with the user equipment 10 may be performed by the base station 20 and/or other nodes other than the base station 20. Obviously, it can be done by a network node (eg, but not limited to MME or S-GW). Although the case where there is one network node other than the base station 20 is exemplified above, it may be a combination of a plurality of other network nodes (for example, MME and S-GW).

Each aspect/embodiment described herein may be used alone, may be used in combination, or may be switched between implementations.

User equipment 10 may be referred to by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, It may also be called a wireless terminal, remote terminal, handset, user agent, mobile client, client or some other suitable term.

Base station 20 may also be referred to by those skilled in the art as a NodeB (NB), an enhanced NodeB (eNB), a Base Station, or some other suitable terminology.

As used herein, the terms "determining" and "determining" may encompass a wide variety of actions. "Judgement", "determining" are, for example, judging, calculating, computing, processing, deriving, investigating, looking up (e.g., table , searching in a database or other data structure), ascertaining what has been "determined" or "determined", and the like. Also, “judgment” and “determination” are used to refer to receiving (e.g., receiving information), transmitting (e.g., transmitting information), input, output, access (accessing) (for example, accessing data in memory) may include deeming that a "judgment" or "decision" has been made. In addition, "judgment" and "decision" refer to resolving, selecting, choosing, establishing, comparing, etc. as "judgment" and "decision". can contain. In other words, "judgment" and "decision" can include considering that some action is "judgment" and "decision".

As used herein, the phrase "based on" does not mean "based only on," unless expressly specified otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

To the extent that "include," "including," and variations thereof are used in the specification or claims, these terms are synonymous with the term "comprising." are intended to be inclusive. Furthermore, the term "or" as used in this specification or the claims is not intended to be an exclusive OR.

Throughout this disclosure, where articles have been added by translation, e.g., a, an, and the in English, these articles are used unless the context clearly indicates otherwise. It can contain more than one.

Although the present invention has been described in detail above, it will be apparent to those skilled in the art that the present invention is not limited to the embodiments described herein. The present invention can be embodied in modifications and variations without departing from the spirit and scope of the invention defined by the claims. Accordingly, the description herein is for the purpose of illustration and explanation, and does not have any limiting meaning to the present invention.
(Section 1)
A communication device for use in a wireless communication system,
a first generator that generates a first data unit to be transmitted to another communication device;
adding a value indicating the size of the first data unit to the first data unit generated by the first generation unit to generate a second data unit including a payload having the first data unit and the value; 2 generator;
a transmitter that transmits the second data unit to the other communication device;
A communication device comprising:
(Section 2)
The second generator generates the second data unit by concatenating a plurality of data having the first data unit and a value indicating the size of the first data unit.
2. The communication device according to claim 1, characterized by:
(Section 3)
The size of the second data unit is a size determined based on available radio resources in the transmitting unit,
The second generator performs the concatenation before the size of the second data unit is determined.
3. The communication device according to claim 2, characterized by:
(Section 4)
the second data unit has a header area;
The second generator includes information corresponding to a position of a predetermined first data unit in the payload in the header area of the second data unit.
The communication device according to any one of items 1 to 3, characterized by:
(Section 5)
A transmission method performed by a communication device used in a wireless communication system, comprising:
a first generating step of generating a first data unit to be transmitted to another communication device;
adding a value indicating the size of the first data unit to the first data unit generated in the first generating step to generate a second data unit including a payload having the first data unit and the value; 2 production step;
a sending step of sending the second data unit to the other communication device;
A transmission method characterized by comprising:

10 User equipment 20 Base station 101 Signal transmission unit 102 Signal reception unit 103 Layer 2 processing unit 113 First generation unit 123 Second generation unit 133 First layer processing unit 143 Second layer processing unit 104 Upper layer processing unit 201 Signal transmission unit 202 signal receiving unit 203 layer 2 processing unit 213 first generation unit 223 second generation unit 233 first layer processing unit 243 second layer processing unit 204 upper layer processing unit 1001 processor 1002 memory 1003 storage 1004 communication device 1005 input device 1006 output Device

Claims (4)

A generator that adds a value indicating the size of the first data unit to the first data unit, and generates a second data unit that includes the first data unit, the value, and another segmented first data unit . When,
a transmitting unit configured to transmit the second data unit to a receiving device;
the second data unit has a header area;
The transmitting device, wherein the generator includes information corresponding to the segmented position in the original other first data unit before segmentation in the header area of the second data unit. 2. The generating unit according to claim 1, wherein the generator generates the second data unit by concatenating a plurality of data having the first data unit and a value indicating the size of the first data unit. transmitter. The size of the second data unit is a size determined based on available radio resources in the transmission unit,
3. The transmitting device according to claim 2, wherein the generator performs the concatenation before the size of the second data unit is determined. A transmission method executed by a transmission device,
a generating step of appending to the first data unit a value indicative of the size of the first data unit to generate a second data unit including the first data unit, the value and other segmented first data units ; When,
a transmitting step of transmitting the second data unit to a receiving device;
the second data unit has a header area;
The transmission method, wherein in the generating step, information corresponding to segmented positions in the original other first data unit before segmentation is included in the header area of the second data unit.

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