WO2021100178A1

WO2021100178A1 - Communication device, communication system, communication method, and non-temporary computer-readable medium storing program

Info

Publication number: WO2021100178A1
Application number: PCT/JP2019/045659
Authority: WO
Inventors: 暢彦伊藤; 勇人逸身; 浩一二瓶; 孝法岩井
Original assignee: 日本電気株式会社
Priority date: 2019-11-21
Filing date: 2019-11-21
Publication date: 2021-05-27

Abstract

The present invention aims to provide a communication device capable of reducing processing delay for retransmission packets. This communication device (10) comprises: a sequence number management unit (11) that associates and manages a first sequence number applied to a first layer of a transmission packet sent to a partner device and a second sequence number applied to a second layer being a lower layer than the first layer; a packet generation unit (12) that applies, to the first layer of a retransmission packet, the first sequence number for a transmitted packet that has not reached the partner device and applies the second sequence number that is associated to the first sequence number and managed, to the second layer of the retransmission packet, if it has been detected that the transmitted packet has not reached the partner device and retransmission control has been executed in the first layer; and a communication unit (13) that sends the retransmission packet to the partner device.

Description

A non-transitory computer-readable medium containing communication devices, communication systems, communication methods, and programs.

This disclosure relates to communication devices, communication systems, communication methods, and programs.

In recent years, the demand for real-time video analysis solutions using network cameras has increased. In a real-time video analysis solution, it is desired that an analysis device receives and analyzes high-quality video data in real time even in an environment where the network is congested.

Patent Document 1 discloses a configuration in which a feedback message is output from the RLC (RadioLinkControl) layer to the application layer in order to notify the application layer of the packet loss at an early stage when a packet loss occurs. There is. Specifically, by using DPI (Deep Packet Inspection), the sequence number of the lost packet in the application layer is grasped, and the sequence number of the application layer is included in the feedback message. This allows the application layer to retransmit the packet with the sequence number included in the feedback message.

Special Table 2016-515775

In the packet retransmission procedure disclosed in Patent Document 1, the transmitting device assigns the sequence number assigned to the lost packet to the application layer of the packet to be retransmitted. However, the transmitting device assigns a new sequence number to a layer lower than the application layer. That is, the transmitting device assigns a sequence number having a value larger than the sequence number assigned to the packet already transmitted to the layer lower than the application layer, and generates a retransmission packet. When the receiving device receives the retransmission packet, the receiving device executes the processing of the packets stored in the buffer in the lower layer than the application layer in order from the lowest sequence number. Therefore, the receiving device cannot execute the retransmission packet in the layer lower than the application layer earlier than the packet already stored in the buffer. As a result, there is a problem that the processing of the retransmitted packet in the application layer is delayed and the low delay service cannot be guaranteed.

An object of the present disclosure is to provide a communication device, a communication system, a communication method, and a program capable of reducing a processing delay of a retransmitted packet.

The communication device according to the first aspect of the present disclosure includes a first sequence number assigned to the first layer of the transmission packet transmitted to the opposite device, and a second layer lower than the first layer. In the first layer when it is detected that the transmission packet has not reached the opposite device and the sequence number management unit that manages the second sequence number assigned to the layer in association with each other. When the retransmission control is executed, the first sequence number of the transmission packet that has not reached the opposite device is assigned to the first layer of the retransmission packet, and the second layer of the retransmission packet is assigned. It includes a packet generation unit that assigns the second sequence number, which is managed in association with the first sequence number, and a communication unit that transmits the retransmission packet to the opposite device.

The communication system according to the second aspect of the present disclosure includes a counter device to which a packet is transmitted, a first sequence number assigned to a first layer of a transmission packet transmitted to the counter device, and the first sequence number. A sequence number management unit that manages the second sequence number assigned to the second layer, which is a layer lower than the first layer, in association with each other, and detects that the transmitted packet has not reached the opposite device. In this case, when the retransmission control is executed in the first layer, the first sequence number of the transmission packet that has not reached the opposite device is assigned to the first layer of the retransmission packet. , A packet generation unit that assigns the second sequence number managed in association with the first sequence number to the second layer of the retransmission packet, and communication for transmitting the retransmission packet to the opposite device. It is provided with a unit and a communication device having the unit.

The communication method according to the third aspect of the present disclosure includes a first sequence number assigned to the first layer of the transmission packet transmitted to the opposite device, and a second layer lower than the first layer. The retransmission control is executed in the first layer even when it is detected that the transmitted packet has not reached the opposite device by managing the second sequence number assigned to the first layer in association with the second sequence number. In this case, the first layer of the retransmission packet is assigned the first sequence number of the transmission packet that has not reached the opposite device, and the second layer of the retransmission packet is the first sequence. The second sequence number, which is managed in association with the number, is assigned, and the retransmission packet is transmitted to the opposite device.

The program according to the fourth aspect of the present disclosure includes a first sequence number assigned to the first layer of the transmission packet transmitted to the opposite device, and a second layer lower than the first layer. Retransmission control is executed in the first layer even when it is detected that the transmitted packet has not reached the opposite device by managing the second sequence number assigned to the layer in association with each other. In this case, the first layer of the retransmission packet is assigned the first sequence number of the transmission packet that has not reached the opposite device, and the second layer of the retransmission packet is assigned the first sequence number. The second sequence number, which is managed in association with the above, is assigned, and the computer is made to execute the retransmission packet to be transmitted to the opposite device.

According to the present disclosure, it is possible to provide a communication device, a communication system, a communication method, and a program capable of reducing the processing delay of the retransmitted packet.

It is a block diagram of the communication apparatus which concerns on Embodiment 1. FIG. It is a block diagram of the communication system which concerns on Embodiment 2. FIG. It is a block diagram of IoT-GW which concerns on Embodiment 2. FIG. It is a figure explaining the management table managed by the sequence number management part which concerns on Embodiment 2. FIG. It is a figure explaining the retransmission control process in IoT-GW which concerns on Embodiment 2. FIG. It is a figure which shows the packet stored in the buffer of the eNB which concerns on Embodiment 2. FIG. It is a figure which shows the packet stored in the buffer of the eNB which concerns on Embodiment 2. FIG. It is a figure which shows the flow of the creation process of the management table which concerns on Embodiment 2. FIG. It is a figure which shows the flow of the transmission processing of the retransmission packet which concerns on Embodiment 2. FIG. It is a block diagram of the communication apparatus and IoT-GW concerning each embodiment.

(Embodiment 1)
Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. A configuration example of the communication device 10 will be described with reference to FIG. The communication device 10 may be a computer device that operates by the processor executing a program stored in the memory. The communication device 10 may be, for example, a mobile phone terminal, a smartphone terminal, a mobile router, an IoT (Internet Of Things) terminal, an MTC (Machine Type Communication) terminal, or the like. Alternatively, the communication device 10 may be an IoT GW (Gateway) that aggregates a plurality of IoT terminals. In the following description, when the application layer is the uppermost layer and the physical layer is the lowest layer, for example, as in the OSI reference model, the layer closer to the physical layer than the layer of interest is referred to as the "lower layer". , And the layer closer to the application layer than the layer of interest is referred to as the "upper layer".

The communication device 10 transmits / receives data to / from the opposite device. The opposite device may be, for example, a base station, a server device, or the like. Alternatively, the opposite device may be a mobile router, IoT GW, or the like.

In the communication device 10, when transmitting a packet, the lower layer adds a header to the data received from the upper layer, and further passes it to the lower layer. In this way, packets with headers are generated in each layer. Further, in the communication device 10, when a packet is received, the upper layer receives the data from which the header has been removed in the lower layer, and further removes the header and passes it to the upper layer. In this way, the upper layer receives the data from which the header of the lower layer has been removed. Packets are processed in the opposite device in the same manner as in the communication device 10.

The opposite device can detect packet loss by confirming the sequence number of the received packet. Packet loss is a state in which the packet transmitted from the communication device 10 has not reached the opposite device. For example, it is assumed that the opposite device receives a packet having a sequence number discontinuous with a previously received sequence number while receiving a packet having a sequence number assigned continuously. In this case, the opposite device detects packet loss. When the opposite device detects the packet loss, it transmits a reception confirmation response message (NACK message) indicating that the packet loss has been detected to the communication device 10. Further, when the opposite device receives the packet normally, the opposite device transmits a reception confirmation response message (ACK message) indicating that the packet has been received normally to the communication device 10.

For example, when the opposite device receives the packet to which the sequence number 2 is assigned next to the packet to which the sequence number 1 is assigned, it determines that the packet having the sequence number assigned continuously is received. On the other hand, when the packet to which the sequence number 2 is assigned is followed by the packet to which the sequence number 4 or later is assigned, it is determined that the packet to which the discontinuous sequence number is assigned is received. When the counter device receives a packet with a discontinuous sequence number, it stores the received packet in a buffer. The counter device does not pass the packet to the upper layer until it receives the packet of the sequence number continuously assigned. The control of packets in such an opposite device may be referred to as sequence control. That is, in the above example, the opposite device does not pass the packet stored in the buffer to the upper layer until the packet to which the sequence number 3 is assigned is received. The sequence number is assigned to the header of each layer. The counter device confirms the sequence number in each layer and determines whether or not packet loss has occurred.

The communication device 10 has a sequence number management unit 11, a packet generation unit 12, and a communication unit 13. The sequence number management unit 11, the packet generation unit 12, and the communication unit 13 may be software or modules whose processing is executed by the processor executing a program stored in the memory. Alternatively, the sequence number management unit 11, the packet generation unit 12, and the communication unit 13 may be hardware such as a circuit or a chip.

The sequence number management unit 11 has a first sequence number assigned to the first layer of the transmission packet transmitted to the opposite device, and a second layer assigned to a second layer lower than the first layer. It is managed in association with the sequence number of 2. Correspondence may be paraphrased as associating or associating. Different communication protocols are defined for the first layer and the second layer. For example, each layer may be defined as a physical layer, a data link layer, a network layer, an application layer, and the like. Alternatively, RLC (RadioLinkControl), PDCP (PacketDataConvergenceProtocol), RTP (RealTimeProtocol), etc. defined by 3GPP (3rd Generation Partnership Project) are used as the communication protocol defined in each layer. May be good. A sequence number is assigned to the packet at each layer. For example, as the sequence number, consecutive numbers may be assigned to a plurality of packets in the order of transmission.

The fact that the sequence number of each layer is associated means that, for example, when the sequence number of the first layer is extracted, the sequence number of the second layer associated with the sequence number of the first layer can also be extracted at the same time. There may be. Also, managing may be replaced with storing, recording, retaining, preserving, preserving, and the like.

When the packet generation unit 12 detects that the transmitted packet has not reached the opposite device, the packet generation unit 12 transmits the retransmission packet to the opposite device. When the packet generation unit 12 detects that the transmitted packet has not reached the opposite device and the retransmission control is executed in the first layer, the packet generation unit 12 attaches the retransmission control to the opposite device in the first layer of the retransmission packet. The first sequence number of the transmitted packet that has not arrived is assigned. Further, the packet generation unit 12 assigns a second sequence number managed in association with the first sequence number to the second layer of the retransmission packet.

The transmission packet does not reach the opposite device is an event that occurs, for example, when a failure or congestion occurs in the communication path between the communication device 10 and the opposite device. Further, when the communication device 10 transmits a packet to the opposite device by performing wireless communication, an event may occur in which the transmitted packet does not reach the opposite device due to deterioration of the communication environment or the like. Further, the fact that the transmitted packet does not reach the opposite device means that packet loss has occurred.

The communication device 10 detects that the transmission packet has not reached the opposite device, for example, when the reception confirmation response message (ACK message) of the transmission packet is not received from the opposite device within a predetermined period. May be good. Alternatively, when the communication device 10 receives the reception confirmation response message (NACK message) indicating that the opposite device has not received the transmission packet, the communication device 10 may detect that the transmission packet has not reached the opposite device. .. The communication device 10 may specify the sequence number of each layer of the packet that did not reach the opposite device by executing DPI (Deep Packet Inspection).

The communication unit 13 transmits the retransmission packet generated by the packet generation unit 12 to the opposite device.

As described above, the communication device 10 can manage the sequence numbers assigned to each layer of the same packet in association with each other in the sequence number management unit 11. Therefore, when it is detected that the transmitted packet has not reached the opposite device and the retransmission control is executed in the first layer, the retransmission packet is the first layer of the packet that has not reached the opposite device. The sequence number in can be assigned. Further, the communication device 10 also assigns the sequence number of the second layer, which is a lower layer of the first layer, associated with the sequence number of the first layer of the packet that has not reached the opposite device to the retransmission packet. can do.

As a result, the opposite device can recognize the sequence number having a lower number than the buffered packet in the processing of the second layer. As a result, the opposite device can recognize that the packet received from the communication device 10 is a retransmission packet, so that the retransmission packet can be processed faster than other buffered packets. As a result, the counter device can pass the retransmission packet from the second layer to the first layer, which is the upper layer, faster than the other buffered packets.

On the other hand, when the communication device assigns the sequence number assigned to the packet that has not reached the opposite device to the first layer and newly assigns the sequence number to the second layer, the opposite device is assigned to the second layer. It cannot be recognized as a retransmission packet in the layer of. As a result, the opposite device stores the received packet in the buffer and cannot deliver the retransmitted packet to the upper layer faster than the other packets stored in the buffer. Therefore, the retransmission packet transmitted from the communication device 10 according to the first embodiment is faster in the opposite device than the retransmission packet transmitted from the communication device that does not manage the sequence numbers of each layer in association with each other. Handed over to the layer.

(Embodiment 2)
Subsequently, a configuration example of the communication system according to the second embodiment will be described with reference to FIG. The communication system of FIG. 2 has an IoT-GW 20 and an eNB (evolved Node B) 30. The IoT-GW 20 corresponds to the communication device 10 in FIG. Further, the eNB 30 corresponds to the opposite device. The IoT-GW 20 communicates with the eNB 30 via a wireless line. The eNB 30 is defined as a base station that supports LTE (Long Term Evolution) in 3GPP (3rd Generation Partnership Project). Further, instead of the eNB 30, a base station that supports a radio standard defined as so-called 5G in 3GPP may be used.

Subsequently, a configuration example of the IoT-GW 20 according to the second embodiment will be described with reference to FIG. The IoT-GW 20 has a sequence number management unit 21, a packet generation unit 22, a communication unit 23, a detection unit 24, and a search unit 25. The sequence number management unit 21, the packet generation unit 22, the communication unit 23, the detection unit 24, and the search unit 25 may be software or modules whose processing is executed by the processor executing a program stored in the memory. Good. Alternatively, the sequence number management unit 21, the packet generation unit 22, the communication unit 23, the detection unit 24, and the search unit 25 may be hardware such as a circuit or a chip.

The sequence number management unit 21, the packet generation unit 22, and the communication unit 23 correspond to the sequence number management unit 11, the packet generation unit 12, and the communication unit 13 included in the communication device 10 of FIG. Therefore, detailed description of the sequence number management unit 21, the packet generation unit 22, and the communication unit 23 will be omitted. Regarding the sequence number management unit 21, the packet generation unit 22, and the communication unit 23, the differences between the sequence number management unit 11, the packet generation unit 12, and the communication unit 13 will be mainly described.

The detection unit 24 detects whether or not the packet transmitted from the IoT-GW 20 to the eNB 30 has reached the eNB 30. That is, the detection unit 24 detects whether or not packet loss has occurred between the IoT-GW 20 and the eNB 30. For example, if the detection unit 24 does not receive the ACK message from the eNB 30 within a predetermined period after transmitting the packet from the communication unit 23 to the eNB 30, or if the detection unit 24 receives the NACK message from the eNB 30, packet loss occurs. It may be determined that it has occurred.

Here, the management table managed by the sequence number management unit 21 will be described with reference to FIG. The management table illustrated in FIG. 4 represents management information including each sequence number (SN: Sequence Number) of the RTP, RLC PDU (Protocol Data Unit), and PDCP PDU of the transmitted packet.

In the management table of FIG. 4, RTP indicates the protocol used in the uppermost layer, and RLC indicates the protocol used in the lowermost layer. PDCP represents a protocol used in the layer between RTP and RLC.

The numbers shown in the management table in FIG. 4 indicate the sequence numbers. For example, the management table manages RTP # 1, PDCP # 1-2, and RLC # 1 in association with each other. That is, each layer of a certain transmitted packet includes an RTP header to which the sequence number 1 is assigned, a PDCP header to which the

sequence numbers

1 and 2 are assigned, and an RLC header to which the sequence number 1 is assigned. Further, each layer of a certain transmitted packet includes an RTP header to which the sequence number 2 is assigned, a PDCP header to which the

sequence numbers

3 and 4 are assigned, and an RLC header to which the sequence number 2 is assigned. Further, each layer of a certain transmitted packet includes an RTP header to which the sequence number 3 is assigned, a PDCP header to which the

sequence numbers

5 and 6 are assigned, and an RLC header to which the sequence number 2 is assigned. Here, the two packets described as having the sequence number 2 assigned to the RLC header may be transmitted to the eNB 30 as one packet. That is, one packet may include an RTP header to which

sequence numbers

2 and 3 are assigned, a PDCP header to which sequence numbers 3 to 6 are assigned, and an RLC header to which sequence numbers 2 are assigned.

The sequence number management unit 21 may add, for example, the sequence number assigned to each layer included in the transmission packet to the management table each time a packet is transmitted from the communication unit 23. For example, the sequence number management unit 21 may specify the sequence number in each layer of the packet transmitted from the communication unit 23 by executing the DPI. Alternatively, the sequence number management unit 21 may add the sequence number assigned in the upper layer to the management table when passing the packet from the upper layer to the lower layer. Alternatively, the sequence number management unit 21 may add to the sequence number assigned in the upper layer and the sequence number assigned in the lower layer and the management table when passing the packet from the upper layer to the lower layer.

Returning to FIG. 3, the search unit 25 uses the sequence number of any layer included in the packet that did not reach the eNB 30 and uses the sequence number of the other layer included in the packet that did not reach the eNB 30 from the management table. Search for a number. Further, the search unit 25 identifies the sequence number of the other layer included in the packet that did not reach the eNB 30 by searching the sequence number of the other layer. Specifying may be paraphrased as selecting or detecting. For example, when retransmission control is executed in the application layer in which RTP is used, the search unit 25 searches for the sequence number assigned to the PDCP header and the RLC header by using the sequence number assigned to the RTP header. The search unit 25 identifies the sequence numbers of the PDCP header and the RLC header by searching the sequence numbers assigned to the PDCP header and the RLC header.

The sequence number included in the packet that did not reach the eNB 30 may be included in the NACK message transmitted from the eNB 30 to the IoT-GW 20, for example. For example, when retransmission control in the application layer is executed, the sequence number assigned to the RTP header of the packet that did not reach the eNB 30 may be included in the NACK message. Alternatively, when retransmission control in the application layer is executed, at least one sequence number of the PDCP header and the RLC header may be included in the NACK message in addition to the sequence number assigned to the RTP header.

Alternatively, the detection unit 24 or the search unit 25 may specify the sequence number included in the packet that did not reach the eNB 30 by executing the DPI.

When the detection unit 24 detects the packet loss related to the packet transmitted from the IoT-GW 20 to the eNB 30, the packet generation unit 22 generates a retransmission packet. For example, the packet generation unit 22 generates a retransmission packet including the sequence number assigned to the RTP header of the packet that did not reach the eNB 30 and the PDCP header and the RLC header specified by the search unit 25. Alternatively, the packet generation unit 22 may generate a retransmission packet including the RTP header, the PDCP header, and the sequence number assigned to the RLC header specified by executing the DPI for the packet that did not reach the eNB 30. Good.

The communication unit 23 transmits the retransmission packet generated by the packet generation unit 22 to the eNB 30. The communication unit 23 may transmit the retransmission packet to the eNB 30 at a predetermined timing, or may transmit the retransmission packet to the eNB 30 at an arbitrary timing.

Subsequently, the retransmission control process in the IoT-GW 20 will be described with reference to FIG. The IoT-GW 20 first transmits a packet containing the RLC header to which the sequence number 1 is assigned, the PDCP header to which the

sequence numbers

1 and 2 are assigned, and the RTP header to which the sequence number 1 is assigned to the eNB 30. Here, in the layer where the RLC protocol is used, the data of the layer where PDCP and RTP are used is treated as a payload. Therefore, in FIG. 5, a packet including an RLC header and a payload is described.

Next, the IoT-GW 20 transmits a packet containing the RLC header to which the sequence number 2 is assigned, the PDCP header to which the sequence numbers 3 to 6 are assigned, and the RTP header to which the

sequence numbers

2 and 3 are assigned to the eNB 30. To do. However, it is assumed that the packet to which the sequence number 2 is assigned to the RLC header has not reached the eNB 30. That is, it is assumed that the packet to which the sequence number 2 is assigned to the RLC header is lost between the IoT-GW 20 and the eNB 30. The packet shown by the dotted line in FIG. 5 indicates that the eNB 30 has not been reached.

Next, the IoT-GW 20 transmits a packet including the RLC header to which the sequence number 3 is assigned, the PDCP header to which the

sequence numbers

7 and 8 are assigned, and the RTP header to which the sequence number 4 is assigned to the eNB 30.

Here, the packet stored in the buffer of the eNB 30 will be described with reference to FIG. When the eNB 30 receives the packet in which the sequence number 1 is assigned to the RLC header and then the packet in which the sequence number 3 is assigned to the RLC header, the sequence number 3 is assigned to the RLC header in the buffer of the eNB 30. The packet is stored. The eNB 30 determines that the packet to which the sequence number 2 is assigned to the RLC header has not been received, and buffers the packets received thereafter. That is, the eNB 30 performs order control at the layer where the RLC protocol is used. The order control may be, for example, executing processing in order from the youngest consecutive sequence number and passing the packet to the upper layer.

In FIG. 6, the packet to which the sequence number 3 is assigned to the RLC header is stored, but the packet to which the sequence number 4 or later is assigned to the RLC header is also stored in the same manner.

Returning to FIG. 5, the IoT-GW 20 retransmits the packet that has not reached the eNB 30 after transmitting the sequence number 3 to the RLC header. Specifically, when the retransmission control in the application layer is executed, the IoT-GW 20 retransmits the packet in which the

sequence numbers

2 and 3 are assigned to the RTP header. At this time, the IoT-GW 20 assigns sequence numbers 3 to 6 to the PDCP header and sequence numbers 2 to the RLC header. The

sequence numbers

3 and 4 assigned to the PDCP header are associated with the sequence number 2 of the RTP header. Further, the

sequence numbers

5 and 6 assigned to the PDCP header are associated with the sequence number 3 of the RTP header. Further, the sequence number 2 assigned to the RLC header is associated with the

sequence numbers

2 and 3 of the RTP header.

Here, the packet stored in the buffer of the eNB 30 will be described with reference to FIG. 7. When the eNB 30 receives a packet in which the sequence number 2 is assigned to the RLC header, the eNB 30 stores the received packet in a buffer. As a result, the eNB 30 recognizes that it has received the packet in which the sequence number 2 is added to the RLC header that has not yet been received. That is, the eNB 30 recognizes that the packet in which the sequence number 2 is added to the RLC header has been retransmitted. Therefore, the eNB 30 removes the RLC header of the packet in which the sequence number 2 or later is added to the RLC header stored in the buffer, and delivers the packet from which the RLC header has been removed to the layer in which PDCP is used.

As described with reference to FIG. 7, even when retransmission control is executed in the application layer, it is recognized as a retransmission packet in the layer using the RLC protocol. Therefore, in the layer using the RLC protocol, the retransmission packet is delivered to the upper layer before other packets stored in the buffer.

Subsequently, with reference to FIG. 8, the flow of the management table creation process executed in the IoT-GW 20 will be described. The sequence number management unit 21 associates the sequence number assigned in the N layer of the packet_A transmitted from the communication unit 23 with the sequence number assigned in the N-1 layer, and adds the sequence number to the management table (S11). .. The N-1 layer is a lower layer of the N layer. For example, the sequence number management unit 21 manages the sequence number assigned in the N layer and the sequence number to be assigned in the N-1 layer at the timing when the packet is delivered from the N layer to the N-1 layer. You may add it to the table. Alternatively, the sequence number management unit 21 may add the sequence numbers assigned in the N layer and the N-1 layer to the management table at the timing when the packet is delivered from the N-1 layer to the N-2 layer. Next, the sequence number management unit 21 associates the sequence number assigned in the N-1 layer of packet_A with the sequence number assigned in the N-2 layer and adds them to the management table (S12). The sequence number management unit 21 executes addition to the management table up to the sequence number of the lowest layer managed in the management table.

Next, when the communication unit 23 completes the addition to the management table for all layers of the packet_A, the communication unit 23 transmits the packet_A (S13).

In FIG. 8, the process of adding the sequence numbers of the two layers to the management table has been described as in steps S11 and S12, but the processes of steps S11 and S12 are performed at once to manage the sequence numbers of three or more layers. You may add it to the table. For example, the sequence number management unit 21 may specify the sequence numbers of all layers by executing DPI for the packet to which the header of the lowest layer is added. The sequence number management unit 21 may add the specified sequence number to the management table.

Further, in FIG. 8, the process of creating the management table before transmitting the packet has been described, but the management table may be created after the packet is transmitted. In this case, the sequence number information given to each layer of the transmitted packet is stored in a memory or the like, and the sequence number management unit 21 adds the sequence number of each layer stored in the memory or the like to the management table. May be good.

Subsequently, with reference to FIG. 9, the flow of the transmission processing of the retransmission packet executed in the IoT-GW 20 will be described. First, the detection unit 24 determines whether or not the packet transmitted from the IoT-GW 20 to the eNB 30 has reached the eNB 30 normally (S21).

When packet loss is detected by the detection unit 24, the search unit 25 searches the management table for the sequence numbers of other layers by using the sequence number of the layer that executes the retransmission control of the lost packet (S22). The search unit 25 identifies the sequence number of the other layer by searching for the sequence number of the other layer. The layer that executes retransmission control of lost packets may be, for example, an application layer. Searching may be paraphrased as detecting or extracting.

Next, the packet generation unit 22 generates a retransmission packet including the sequence number of the layer that executes the retransmission control of the lost packet and the specified sequence number (S23). Next, the communication unit 23 transmits the retransmission packet generated by the packet generation unit 22 to the eNB 30 (S24). Further, in step S21, when the detection unit 24 determines that the packet transmitted from the IoT-GW 20 to the eNB 30 has reached the eNB 30 normally, the process ends.

As described above, the IoT-GW 20 according to the second embodiment can manage the sequence number of each layer included in the packet transmitted to the eNB 30. From this, when the IoT-GW 20 executes the retransmission control in the application layer, the sequence number assigned to the packet that did not reach the eNB 30 is also used as the sequence number assigned in the layer lower than the application layer. Can be done. In addition to the case where the retransmission control is executed in the application layer, when the retransmission control is executed in another layer, similarly, in the layer lower than the layer in which the retransmission control is executed, the packet that did not reach the eNB 30 The assigned sequence number can be used.

Further, in the second embodiment, the case where the order control is performed in the layer in which the RLC protocol of the eNB 30 is used is described. For example, when the order control is performed in the layer in which the PDCP of the eNB 30 is used, the IoT-GW 20 does not have to manage the sequence number assigned to the RLC header in the management table. That is, the IoT-GW 20 may manage the sequence number assigned to the layer in which the order control is performed in the eNB 30 in the management table.

Further, when the order control is performed only in the layer in which the RLC protocol is used, the IoT-GW 20 assigns the sequence number assigned to the packet that did not reach the eNB 30 to the RLC header, and assigns the sequence number to the other headers. May be assigned any sequence number. Alternatively, the IoT-GW 20 assigns the sequence number assigned to the packet that did not reach the eNB 30 to the RLC header, and it is not necessary to set data in the payload for the RLC header. When the eNB 30 receives such a retransmission packet, the eNB 30 can deliver the retransmission packet from the layer in which the RLC protocol is used from the layer to the upper layer faster than other packets stored in the buffer. Since the eNB 30 does not perform processing according to the order of the sequence numbers set in the header in the layer in which the order control is not performed, even if an arbitrary sequence number is assigned, the eNB 30 is used for order control. Packets are not accumulated in the buffer.

Subsequently, in the following, a configuration example of the communication device 10 and the IoT-GW 20 (hereinafter referred to as the communication device 10 and the like) described in the plurality of embodiments described above will be described.

FIG. 10 is a block diagram showing a configuration example of the communication device 10 and the like. Radio Frequency (RF) transceiver 1101 performs analog RF signal processing to communicate with the eNB 30. The analog RF signal processing performed by the RF transceiver 1101 includes frequency up-conversion, frequency down-conversion, and amplification. The RF transceiver 1101 is coupled with the antenna 1102 and the baseband processor 1103. That is, the RF transceiver 1101 receives modulation symbol data (or OFDM (Orthogonal Frequency Division Multiplexing) symbol data) from the baseband processor 1103, generates a transmission RF signal, and supplies the transmission RF signal to the antenna 1102. Further, the RF transceiver 1101 generates a baseband reception signal based on the reception RF signal received by the antenna 1102, and supplies the baseband reception signal to the baseband processor 1103.

The baseband processor 1103 performs digital baseband signal processing (data plane processing) and control plane processing for wireless communication. Digital baseband signal processing includes (a) data compression / decompression, (b) data segmentation / concatenation, and (c) transmission format (transmission frame) generation / decomposition. Furthermore, digital baseband signal processing includes OFDM symbol data (baseband OFDM) by (d) transmission path coding / decoding, (e) modulation (symbol mapping) / demodulation, and (f) Inverse Fast Fourier Transform (IFFT). Includes signal) generation and the like. On the other hand, the control plane processing includes layer 1 (eg, transmission power control), layer 2 (eg, wireless resource management, and hybrid automatic repeat request (HARQ) processing), and layer 3 (eg, attach, mobility, and call management). Includes communication management of).

For example, in the case of LTE and 5G, the digital baseband signal processing by the baseband processor 1103 may include signal processing of the Packet Data Convergence Protocol (PDCP) layer, RadioLink Control (RLC) layer, MAC layer, and PHY layer. .. Further, the control plane processing by the baseband processor 1103 may include the processing of the Non-Access Stratum (NAS) protocol, the RRC protocol, and the MAC CE.

The baseband processor 1103 includes a modem processor (eg, Digital Signal Processor (DSP)) that performs digital baseband signal processing, a protocol stack processor (eg, Central Processing Unit (CPU)) that performs control plane processing, or a Micro Processing Unit. (MPU)) may be included. In this case, the protocol stack processor that performs the control plane processing may be shared with the application processor 1104 described later.

The application processor 1104 is also called a CPU, MPU, microprocessor, or processor core. The application processor 1104 may include a plurality of processors (a plurality of processor cores). The application processor 1104 realizes various functions such as the communication device 10 by executing a system software program (Operating System (OS)) read from the memory 1106 or a memory (not shown) and various application programs. The application program may be, for example, a call application, a WEB browser, a mailer, a camera operation application, or a music playback application.

In some implementations, the baseband processor 1103 and the application processor 1104 may be integrated on one chip, as shown by the broken line (1105) in FIG. In other words, the baseband processor 1103 and the application processor 1104 may be implemented as one System on Chip (SoC) device 1105. SoC devices are sometimes referred to as system Large Scale Integration (LSI) or chipsets.

Memory 1106 is a volatile memory, a non-volatile memory, or a combination thereof. The memory 1106 may include a plurality of physically independent memory devices. The volatile memory is, for example, Static Random Access Memory (SRAM) or Dynamic RAM (DRAM) or a combination thereof. The non-volatile memory can be a mask ReadOnlyMemory (MROM), an Electrically ErasableProgrammableROM (EEPROM), a flash memory, or a hard disk drive, or any combination thereof. For example, memory 1106 may include external memory devices accessible from baseband processor 1103, application processor 1104, and SoC 1105. The memory 1106 may include a built-in memory device integrated in the baseband processor 1103, the application processor 1104, or the SoC 1105. Further, the memory 1106 may include the memory in the Universal Integrated Circuit Card (UICC).

The memory 1106 may store a software module (computer program) including instruction groups and data for performing processing by the communication device 10 and the like described in the plurality of embodiments described above. In some implementations, the baseband processor 1103 or application processor 1104 is configured to read the software module from memory 1106 and execute it to perform processing such as the communication device 10 described in the above embodiment. May be good.

Note that this disclosure is not limited to the above-described embodiment, and can be appropriately modified without departing from the spirit.

Part or all of the above embodiments may be described as in the following appendix, but are not limited to the following.

(Appendix 1)
The first sequence number assigned to the first layer of the transmission packet transmitted to the opposite device and the second sequence number assigned to the second layer, which is a layer lower than the first layer, are assigned. The sequence number management unit that manages in association with each other
When it is detected that the transmission packet has not reached the opposite device and the retransmission control is executed in the first layer, the retransmission control has reached the first layer of the retransmission packet. A packet to which the first sequence number of the transmitted packet is assigned and the second sequence number managed in association with the first sequence number is assigned to the second layer of the retransmission packet. Generator and
A communication device including a communication unit that transmits the retransmission packet to the opposite device.
(Appendix 2)
The sequence number management unit
The communication according to Appendix 1, which has management information associated with the first sequence number assigned to the first layer of the transmitted packet and the second sequence number assigned to the second layer. apparatus.
(Appendix 3)
The sequence number management unit
The communication device according to Appendix 2, wherein a sequence number assigned to each layer of the transmission packet is added to the management information before the packet is transmitted to the opposite device.
(Appendix 4)
When a predetermined period has elapsed from the transmission of the packet to the opposite device to the reception of the reception confirmation packet from the opposite device, or the above indicating that the packet has not been received from the opposite device. The communication device according to any one of Supplementary note 1 to 3, further comprising a detection unit that detects that the transmission packet has not reached the opposite device when the reception confirmation packet is received.
(Appendix 5)
The detection unit
When it is detected that the opposite device has not received the transmission packet, the reception confirmation including the first sequence number assigned to the first layer on which the retransmission control of the transmission packet is executed is executed. The communication device according to Appendix 4, which receives a packet.
(Appendix 6)
The detection unit
When it is detected that the opposite device has not received the transmission packet, the first sequence number and the second sequence number assigned to the first layer on which the retransmission control of the transmission packet is executed is executed. The communication device according to Appendix 5, which receives the reception confirmation packet including the second sequence number assigned to the layer.
(Appendix 7)
The packet generator
The communication device according to any one of Supplementary note 1 to 6, wherein a sequence number is assigned to the header of each layer of the retransmission packet, and no data is set in the payload of each layer of the retransmission packet.
(Appendix 8)
The other device to which the packet is sent and
The first sequence number assigned to the first layer of the transmission packet transmitted to the opposite device, and the second sequence number assigned to the second layer, which is a layer lower than the first layer. When the sequence number management unit that manages the packets in association with each other and when it is detected that the transmitted packet has not reached the opposite device and the retransmission control is executed in the first layer, the retransmission packet of the retransmission packet The first sequence number of the transmission packet that has not reached the opposite device is assigned to the first layer, and the second layer of the retransmission packet is managed in association with the first sequence number. A communication system including a packet generation unit that assigns the second sequence number, and a communication device that transmits the retransmission packet to the opposite device.
(Appendix 9)
The sequence number management unit
The communication according to Appendix 8, which has management information associated with the first sequence number assigned to the first layer of the transmitted packet and the second sequence number assigned to the second layer. system.
(Appendix 10)
The first sequence number assigned to the first layer of the transmission packet transmitted to the opposite device and the second sequence number assigned to the second layer, which is a layer lower than the first layer, are assigned. Associate and manage,
When it is detected that the transmission packet has not reached the opposite device and the retransmission control is executed in the first layer, the retransmission control has reached the first layer of the retransmission packet. The first sequence number of the transmitted packet is assigned, and the second sequence number managed in association with the first sequence number is assigned to the second layer of the retransmission packet.
A communication method executed in a communication device that transmits the retransmission packet to the opposite device.
(Appendix 11)
The first sequence number assigned to the first layer of the transmission packet transmitted to the opposite device and the second sequence number assigned to the second layer, which is a layer lower than the first layer, are assigned. Associate and manage,
When it is detected that the transmission packet has not reached the opposite device and the retransmission control is executed in the first layer, the retransmission control has reached the first layer of the retransmission packet. The first sequence number of the transmitted packet is assigned, and the second sequence number managed in association with the first sequence number is assigned to the second layer of the retransmission packet.
A non-transitory computer-readable medium containing a program that causes a computer to execute the retransmission packet to the opposite device.

10 Communication device 11 Sequence number management unit 12 Packet generation unit 13 Communication unit 20 IoT-GW
21 Sequence number management unit 22 Packet generation unit 23 Communication unit 24 Detection unit 25 Search unit 30 eNB

Claims

The first sequence number assigned to the first layer of the transmission packet transmitted to the opposite device and the second sequence number assigned to the second layer, which is a layer lower than the first layer, are assigned. The sequence number management unit that manages in association with each other
When it is detected that the transmission packet has not reached the opposite device and the retransmission control is executed in the first layer, the retransmission control has reached the first layer of the retransmission packet. A packet to which the first sequence number of the transmitted packet is assigned and the second sequence number managed in association with the first sequence number is assigned to the second layer of the retransmission packet. Generator and
A communication device including a communication unit that transmits the retransmission packet to the opposite device.
The sequence number management unit
The first aspect of the present invention, which has management information in which the first sequence number assigned to the first layer of the transmitted packet and the second sequence number assigned to the second layer are associated with each other. Communication device.
The sequence number management unit
The communication device according to claim 2, wherein a sequence number assigned to each layer of the transmission packet is added to the management information before the packet is transmitted to the opposite device.
When a predetermined period has elapsed from the transmission of the packet to the opposite device to the reception of the reception confirmation packet from the opposite device, or the above indicating that the packet has not been received from the opposite device. The communication device according to any one of claims 1 to 3, further comprising a detection unit that detects that the transmission packet has not reached the opposite device when a reception confirmation packet is received.
The detection unit
When it is detected that the opposite device has not received the transmission packet, the reception confirmation including the first sequence number assigned to the first layer on which the retransmission control of the transmission packet is executed is executed. The communication device according to claim 4, which receives a packet.
The detection unit
When it is detected that the opposite device has not received the transmission packet, the first sequence number and the second sequence number assigned to the first layer on which the retransmission control of the transmission packet is executed is executed. The communication device according to claim 5, wherein the reception confirmation packet including the second sequence number assigned to the layer is received.
The packet generator
The communication device according to any one of claims 1 to 6, wherein a sequence number is assigned to the header of each layer of the retransmission packet, and no data is set in the payload of each layer of the retransmission packet.
The other device to which the packet is sent and
The first sequence number assigned to the first layer of the transmission packet transmitted to the opposite device, and the second sequence number assigned to the second layer, which is a layer lower than the first layer. When the sequence number management unit that manages the packets in association with each other and when it is detected that the transmitted packet has not reached the opposite device and the retransmission control is executed in the first layer, the retransmission packet of the retransmission packet The first sequence number of the transmission packet that has not reached the opposite device is assigned to the first layer, and the second layer of the retransmission packet is managed in association with the first sequence number. A communication system including a packet generation unit that assigns the second sequence number, and a communication device that transmits the retransmission packet to the opposite device.
The sequence number management unit
The eighth aspect of the present invention, which has management information in which the first sequence number assigned to the first layer of the transmitted packet and the second sequence number assigned to the second layer are associated with each other. Communications system.
The first sequence number assigned to the first layer of the transmission packet transmitted to the opposite device and the second sequence number assigned to the second layer, which is a layer lower than the first layer, are assigned. Associate and manage,
When it is detected that the transmission packet has not reached the opposite device and the retransmission control is executed in the first layer, the retransmission control has reached the first layer of the retransmission packet. The first sequence number of the transmitted packet is assigned, and the second sequence number managed in association with the first sequence number is assigned to the second layer of the retransmission packet.
A communication method executed in a communication device that transmits the retransmission packet to the opposite device.
The first sequence number assigned to the first layer of the transmission packet transmitted to the opposite device and the second sequence number assigned to the second layer, which is a layer lower than the first layer, are assigned. Associate and manage,
When it is detected that the transmission packet has not reached the opposite device and the retransmission control is executed in the first layer, the retransmission control has reached the first layer of the retransmission packet. The first sequence number of the transmitted packet is assigned, and the second sequence number managed in association with the first sequence number is assigned to the second layer of the retransmission packet.
A non-transitory computer-readable medium containing a program that causes a computer to execute the retransmission packet to the opposite device.