WO2021199390A1

WO2021199390A1 - Terminal and communication method

Info

Publication number: WO2021199390A1
Application number: PCT/JP2020/015121
Authority: WO
Inventors: 皓平原田; 明人花木; 高橋　秀明; 天楊閔
Original assignee: 株式会社Ｎｔｔドコモ
Priority date: 2020-04-01
Filing date: 2020-04-01
Publication date: 2021-10-07
Also published as: JPWO2021199390A1

Abstract

A terminal provided with: a transmission unit that, when first context for data communication has been established and second context for data communication is to be newly established, transmits part or all of the second context and an expanded context identifier containing an identifier which is for the second context and a flag which indicates whether or not to refer to the first context as reference context; a reception unit that receives feedback corresponding to the second context; and a control unit that, in response to receipt of the feedback by the reception unit, applies a compression header at the time of data transmission.

Description

Terminal and communication method

The present invention relates to a terminal and a communication method in a wireless communication system.

In the Ethernet (registered trademark) header compression procedure, the compressor notifies the compressor of the Full Header (FH) of a certain packet and the Context ID (CID) associated with the FH. The de-compressor notifies the compresor of the feedback corresponding to the context. Upon receiving the feedback, the compressor determines that the context has been established and begins compressing the header. That is, the compressor transmits the compressed header (CH: Compressed Header) to the de-compressor.

Discussions are being held at the 3GPP meeting regarding the design of the CID field (details of bit allocation). It has been agreed to support the design of 1 octet (= 8 bits) and 2 octets extended CID fields. It has also been agreed to notify by RRC signaling which of the 1 octet extended CID field and the 2 octet extended CID field to use.

When establishing a new context, the Ethernet Full Header is transmitted from the compressor to the de-compressor in order to assign the CID to the Ethernet Full Header, which may increase the overhead.

There is a need for a way to reduce the overhead of establishing a new context.

According to one aspect of the present invention, when a first context for data communication is established and a second context for data communication is newly established, the second context An extended context identifier including an identifier and a flag indicating whether or not to refer to the first context as a reference context, and a transmitter for transmitting a part or all of the second context. A terminal comprising a receiving unit that receives feedback corresponding to the second context, and a control unit that applies a compression header when transmitting data in response to the receiving unit receiving the feedback. Is provided.

According to the embodiment, a method of reducing the overhead in establishing a new context is provided.

It is a figure which shows the example of the structure of the communication system in this embodiment. It is a figure which shows the Uu interface between a terminal and 5G-AN. It is a figure which shows the example of the header compression procedure. It is a figure which shows the example of the structure of Full Header. It is a figure which shows the example of the design of the extended CID field. It is a figure which shows the example of the design of the extended CID field. It is a figure which shows the example of the design of the extended CID field. It is a figure which shows the example of the design of the extended CID field. It is a figure which shows the example of the subfield of 802.Q TAG. It is a figure which shows the example of the design of the extended CID field of one octet. It is a figure which shows the example of the extended CID field which expanded the size when the Reference CID flag bit is 1. It is a figure which shows the example of the process which establishes a new context using a reference context. It is a figure which shows the example of a reference context and a new context. It is a figure which shows the example which does not include the 802.1Q TAG field in the extended CID field. It is a figure which shows the example of the extended CID field which can be used when 802.1Q TAG is included. It is a figure which shows the example of the extended CID field which can be used when 802.1Q TAG is included. It is a figure which shows the example of the extended CID field when the CID is 6 bits. It is a figure which shows the example of the extended CID field when the CID is 6 bits. It is a figure which shows the example of the extended CID field when the CID is 7 bits. It is a figure which shows the example which uses the format of 1 octet of CID + 1 octet of reference CID. It is a figure which shows an example of the functional structure of a terminal. It is a figure which shows an example of the functional structure of a base station. It is a figure which shows an example of the hardware composition of a terminal and a base station.

Hereinafter, embodiments of the present invention will be described 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 wireless communication system in the following embodiment basically conforms to NR, but this is an example, and the wireless communication system in the present embodiment is a wireless communication system other than NR in a part or all of the wireless communication system. It may be compliant with a communication system (eg LTE, LTE-A).

(Overall system configuration)
FIG. 1 is a diagram showing an example of a configuration of a wireless communication system according to the present embodiment. As shown in FIG. 1, the wireless communication system according to the present embodiment includes a terminal 10 and a base station 20 (which may be a base station simulator). Although FIG. 1 shows one terminal 10 and one base station 20, this is an example, and there may be a plurality of each. When a base station simulator is used instead of the base station 20, instead of forming a cell as shown in FIG. 1, a fading simulator and an attenuator are used between the base station simulator and the terminal 10. The test environment may be configured by connecting the base station simulator and the terminal 10 with a coaxial cable or the like after interposing such as.

The terminal 10 is a communication device having a wireless communication function such as a smartphone, a mobile phone, a tablet, a wearable terminal, and a communication module for M2M (Machine-to-Machine), and is wirelessly connected to the base station 20 by a wireless communication system. Use the various communication services provided. The base station 20 is a communication device that provides one or more cells and wirelessly communicates with the terminal 10.

In the present embodiment, the duplex system may be a TDD (Time Division Duplex) system or an FDD (Frequency Division Duplex) system.

Further, in the embodiment of the present invention, when the radio parameter or the like is "configured" or "defined", a predetermined value is pre-configured in the base station 20 or the terminal 10. This may be the case, or it may be assumed that the base station 20 or the terminal 10 is pre-configured, or the radio parameter notified from the base station 20 or the terminal 10 is set. It may be set.

The base station 20 is a communication device that provides one or more cells and performs wireless communication with the terminal 10. The physical resources of the radio signal are defined in the time domain and the frequency domain, the time domain may be defined by the number of OFDM symbols (slots, subframes, symbols, time resources shorter than the symbols, etc.), and the frequency domain may be defined. It may be defined by the number of subcarriers or the number of resource blocks. The base station 20 transmits a synchronization signal and system information to the terminal 10. Synchronous signals are, for example, NR-PSS and NR-SSS. A part of the system information is transmitted by, for example, NR-PBCH, and is also referred to as broadcast information. The synchronization signal and the broadcast information may be periodically transmitted as an SS block (SS / PBCH block) composed of a predetermined number of OFDM symbols. For example, the base station 20 transmits a control signal or data to the terminal 10 by DL (Downlink), and receives the control signal or data from the terminal 10 by UL (Uplink). Both the base station 20 and the terminal 10 can perform beamforming to transmit and receive signals. For example, the reference signal transmitted from the base station 20 includes CSI-RS (Channel State Information Reference Signal), and the channels transmitted from the base station 20 are PDCCH (Physical Downlink Control Channel) and PDSCH (Physical Digital). including.

(EHC)
Release 16 of 3GPP defines Ethernet® Header Compression (EHC) for IoT (Industrial Internet of Things).

For example, as shown in the example of FIG. 2, when transmitting and receiving an Ethernet frame between a terminal and 5G-AN (Uu interface), the Ethernet header of the Ethernet frame is compressed.

For example, in the case of uplink communication, the Ethernet header compressed by the Packet Data Transmission Protocol (PDCP) entity of the terminal (UE) is decompressed by the PDCP entity of 5G-AN, and the remote controller is decompressed using the decompressed header information. The packet is transmitted to.

In the following description, the base station may have a compressor and a de-compressor, and the terminal may have a compressor and a de-compressor. In the case of downlink communication, the base station may operate as a compressor and the terminal may operate as a de-compressor. Further, in the case of uplink communication, the base station may operate as a de-compressor, and the terminal may operate as a compressor. In the following description, the context may be the content of the Ethernet Header.

FIG. 3 is a diagram showing an example of an Ethernet header compression procedure. The compressor and de-compressor compress the Ethernet (registered trademark) header as follows. In step S101, the compressor notifies the decompressor of the Full Header (FH) of a certain packet and the Context ID (CID) associated with the FH.

In step S102, the de-compressor notifies the compresor of the feedback corresponding to the context.

The compressor that received the feedback in step S102 determines that the context has been established, and starts compressing the header. That is, the compressor transmits the compressed header (CH: Compressed Header) to the de-compressor in step S103.

In the above description, establishing a context may mean establishing a state in which the same Ethernet Header content is shared between the compressor side and the de-compressor side.

The above-mentioned Ethernet Header Compression (EHC) is executed by PDCH entity. The order of protocol headers higher than PDCP may be as follows.

PDCP header | SDAP header | EHC header | ROHC header | payload

In this specification, for convenience of explanation, Robust Header Compression (ROHC) header is not described. However, the PDCP entity that transmits the user plane data may use the ROHC compressor to compress the ROHC header.

The EHC function can be applied in units of Data Radio Bearer (DRB) that transmits user plane data. Further, the EHC function can be applied to both the uplink and the downlink. When adding the DRB, the base station may notify the terminal by RRC signaling whether or not to compress the Ethernet header.

FIG. 4 is a diagram showing an example of the configuration of Ethernet Full Header. A CID is assigned before the Ethernet Full Header. As shown in the example of FIG. 4, the Ethernet Full Header is a 7-octet preamble, a 1-octet start of Frame deleter (SFD), a 6-octet destination address, a 6-octet source address, and a 4-octet 802.1Q. TAG, 2 octets of LENGTH / TYPE, 42 to 1500 octets of PAYLOAD (+ PAD), 4 octets of FRAME CHECK SEQUENCE (FCS) may be included.

FIG. 7 is a diagram showing an example of a subfield of 802.1Q TAG. 802.1Q TAG includes Tag Protocol Identifier (TPID), Priority Code Point (PCP), Canonical Format Indicator (CFI) (or Drop eligible Identifier (DEI)), and VLAN ID. The TPID is a 16-bit field in which a fixed value of 0x8100 is set to indicate that it is a tagged frame according to IEEE802.1Q. The PCP is a 3-bit field that specifies the priority defined in IEEE802.1p. Frame priorities are indicated by 0 (lowest) to 7 (highest) and can be used to prioritize various types of traffic (audio, video, data, etc.). CFI is a 1-bit field, and 1 indicates that the MAC address is not in regular format. If 0, the MAC address is in regular format. In the case of Ethernet, it is always 0. The VID is a 12-bit field and specifies the VLAN to which the frame belongs.

In the following description, the field may be each element of the Ethernet header and the CID. The types of fields may include CID, transmission MAC address, reception Mac address, Type / Length, and 802.1Q TAG. The value may be a value stored in the field. Further, the Ethernet frame may be an Ethernet header + payload.

(New Context Establishment using Reference CID in EtherHead Compression)
The design of the CID field (details of bit allocation) shown in FIG. 4 is being discussed at the 3GPP meeting. It has been agreed to support the design of 1 octet (= 8 bits) and 2 octets extended CID fields. It has also been agreed to notify by RRC signaling which of the 1 octet extended CID field and the 2 octet extended CID field to use.

Further, regarding the design of the extended CID field, the CID field is set to 7 bits, and the FH / CH format indication (flag indicating whether the received header is FH or CH) is set to 1 bit. Several designs have been proposed that include other bitfields.

FIG. 5A is a diagram showing an example of an extended CID field design. In the example of FIG. 5A, 7 bits are assigned to the CID and 1 bit is assigned to the F / C (indicating whether the header is Full Header or Compressed Header).

FIG. 5B is a diagram showing another example of the design of the extended CID field. In the example of FIG. 5B, 6 bits are assigned to the CID, 1 bit is assigned to the R (reserved bit), and the remaining 1 bit is assigned to the F / C.

FIG. 6A is a diagram showing another example of the design of the extended CID field. In the example of FIG. 6A, 15 bits are assigned to the CID and 1 bit is assigned to the F / C.

FIG. 6B is a diagram showing another example of the design of the extended CID field. In the example of FIG. 6B, 14 bits are assigned to the CID, 1 bit is assigned to the R, and the remaining 1 bit is assigned to the F / C.

(About issues)
When establishing a context using one Ethernet Full Header and establishing another context using another Ethernet Full Header, among all the fields included in the one Ethernet Full Header. If the value assigned to at least one of the fields is different from the value assigned to the corresponding field of another Ethernet Full Header, then the new CID (ie, that is, for that other Ethernet Full Header). It is assumed that a CID different from the CID associated with one Ethernet Full Header described above) is assigned.

Currently, in order to assign a new CID to the other Ethernet Full Header, the other Ethernet Full Header must be transmitted from the compressor to the de-compressor, which may increase the overhead.

As shown in the following example, when a context is established using a certain Ethernet Full Header, and a new context is established using a new Ethernet Full Header, one of the new Ethernet Full Headers is used. It is conceivable that the values of some or most of the fields are the same as the values of some or most of the Ethernet Full Header described above.

For example, in the example of FIG. 2, when there is one Remote Controller and the same application is often used, some fields (in the case of a downlink, the source) even if they have different contexts. MAC address) is likely to be the same.

As another example, since PCP (Priority Code Point), which is a subfield of 802.1Q TAG, is a field for prioritizing data, only the value of the PCP field is available among all the fields of Ethernet Full Header. It may have changed and the values of the other fields may be the same. Similarly, it is possible that only the values in the DEI field are changed and the values in the other fields are the same.

(Proposal method 1)
In order to solve the above-mentioned problem, the Reference CID flag field may be introduced in the extended CID field. For example, when the Reference CID flag field is introduced into the extended CID field, the reserve bit may be 2 bits. Note that this embodiment is not limited to this example, and the reserve bit may be 1 bit or 3 bits or more.

FIG. 8 is a diagram showing an example of a 1-octet extended CID field design. As shown in FIG. 8, in the 1-octet extended CID field, 6 bits may be assigned to the CID, 2 bits may be assigned to the Reservation bit, and the remaining 1 bit may be assigned to the F / C.

In the example of FIG. 8, the reserve bit may be used as an extended CID bit, a profile flag bit, or a Reference CID flag bit.

(Proposal method 2)
When establishing a new context, the CID of the already established context may be used as a reference CID, and the compressor may notify the de-compressor.

Then, among all the fields of the new context Ethernet Full Header, the reference CID is used for the fields that have the same values as the values of the corresponding fields of the already established Ethernet Full Header. It may be used to make the de-compressor refer to the value of the corresponding field of the Ethernet Full Header, which is an already established context.

Here, the referenced context (that is, the content of the already established Ethernet Full Header that is referenced) may be defined as the reference context, and the CID of the reference context may be defined as the reference CID.

When establishing a new context, if the value of the field with the new context is the same as the value of the corresponding field of the already established context, the field with the new context is sent to the Ethernet Header to be transmitted. It does not have to be included.

The fact that the Reference CID flag bit is 0 may indicate that the size of the CID field does not need to be expanded as shown in the example of FIG. 8 (in the example of FIG. 8, the size of the CID field is 1 octet). On the other hand, the fact that the Reference CID flag bit is 1 may indicate that the size of the CID field needs to be expanded, as shown in the example of FIG.

FIG. 9 is a diagram showing an example of an extended CID field with an expanded size when the Reference CID flag bit is 1. In the example of FIG. 9, "S" may correspond to "SOURCE ADDRESS" in the example of FIG. In the example of FIG. 9, "D" may correspond to "DESTITION ADDRESS" in the example of FIG. In the example of FIG. 9, "T / L" may correspond to "LENGTH / TYPE" in the example of FIG. In the example of FIG. 9, "TPID", "PCP", "CFI", and "VID" may be subfields of "802.1Q TAG" in the example of FIG.

For example, in the example of FIG. 9, the fact that the S bit is 1 may indicate that the value of "SOURCE ADRESS" is the same as the value of "SOURCE ADRESS" in the context corresponding to the reference CID. In addition, for "D", "T / L", "TPID", "PCP", "CFI", and "VID", the fact that the bit is 1 is the value of the corresponding field in the context corresponding to the reference CID. May be shown to be the same as.

For example, in the example of FIG. 9, it is assumed that the S bit and the D bit are 1 respectively, and "T / L", "TPID", "PCP", "CFI", and "VID" are zero. FIG. 11 is a diagram showing an example of a referenced context and a new context in this case. As shown in FIG. 11, when establishing a new context, "SOURCE ADDRESS" and "DESTITION ADDRESS" are not transmitted in the new Ethernet Header transmitted from the compressor to the de-compressor. In this case, the de-compressor refers to the "SOURCE ADDRESS" and "DESTINATION ADDRESS" fields of the already established referenced context, and thereby the value of the "SOURCE ADDRESS" field in the new Ethernet Header and the "DESTINATION ADDRESS". You may set the value of the field.

FIG. 10 is a diagram showing an example of a process of establishing a new context using a reference context. In the example of FIG. 10, it is assumed that the base station 20 performs the process corresponding to the compressor of FIG. 3 and the terminal 10 performs the process corresponding to the decompressor of FIG. However, the embodiment is not limited to this example, and the base station 20 may perform the decompressor process, and the terminal 10 may perform the compressor process. Further, it is assumed that Ethernet Device 1 and Ethernet Device 2 are connected to the terminal 10. The Ethernet Device 1 and the Ethernet Device 2 may be, for example, sensors. Further, it is assumed that the MAC address of Ethernet Device 1 is Address 1 and the MAC address of Ethernet Device 2 is Address 2.

First, in step S201, an RRC connection is set between the base station 20 and the terminal 10.

Next, in step S202, Data Radio Bearer (DRB) is set between the base station 20 and the terminal 10.

Next, in step S203, the base station 20 starts a process of establishing a context 1 with the terminal 10 in order to transmit data to the Ethernet Device 1. Specifically, in step S203, the base station 20 transmits the Ethernet Full Header and the Context ID (CID) associated with the FH to the terminal 10. The value of the CID field transmitted by the base station 20 to the terminal 10 in step S203 is set to CID1 which is the context ID of the context 1, and the value of the "SOURCE ADDRESS" field in FH is set to the MAC address of the remote controller. The value of the "DESTITION ADDRESS" field in FH is set to Address 1, which is the MAC address of Ethernet Device 1.

After receiving the FH transmitted from the base station 20 and the CID associated with the FH in step S203, the terminal 10 transmits feedback corresponding to the context to the base station 20 in step S204.

After receiving the feedback transmitted from the terminal 10 in step S204, the base station 20 determines that the context has been established and starts compressing the header. That is, the compressor transmits data to Ethernet Device 1 using the compressed header (CH: Compressed Header) after step S205.

Next, in step S206, the base station 20 starts a process of establishing a context 2 with the terminal 10 in order to transmit data to the Ethernet Device 2. In this case, among the contexts 2 established with the terminal 10, the value of the "DESTITION ADDRESS" field is set to Address 2, which is the MAC address of Ethernet Device 2, but the value of the "SOURCE ADDRESS" field is. , The MAC address of the remote controller, which is the same as the value in the "SOURCE ADDRESS" field of the context established in step S204. Therefore, the base station 20 uses, for example, an extended extended CID field of the size shown in FIG. 9 to establish a context 2 with the terminal 10. Specifically, the base station 20 sets the value of the Reference CID flag field of the expanded CID field shown in FIG. 9 to 1, and sets the value of the FH / CH field to the bit value corresponding to FH. Then, the value of the S field is set to 1, and the reference CID is set to CID1. Then, in step S206, the base station 20 transmits an Ethernet Header that does not include "SOURCE ADDRESS" and an extended CID field of the above size to the terminal 10.

After receiving the Ethernet Header not including "SOURCE ADDRESS" transmitted from the base station 20 in step S206 and the expanded CID of the size associated with the Ethernet Header, the terminal 10 receives the extended CID of the size. Based on, the value of the "SOURCE ADDRESS" field of the Ethernet Header is set to the MAC address of the remote controller, and a new Ethernet Full Header is set by referring to the CID1 as the reference CID. Then, in step S207, the terminal 10 transmits feedback corresponding to the new context to the base station 20.

After receiving the feedback transmitted from the terminal 10 in step S207, the base station 20 determines that a new context has been established, and starts compressing the header. That is, the compressor transmits data to Ethernet Device 2 using the compressed header (CH: Compressed Header) after step S208. In the example of the process of establishing a new context using the above-mentioned reference context, when the context 1 is set between the base station 20 and the terminal 10 and then the context 2 is set, the context 1 is set. It is used as a reference context. However, this example is not limited to this example. For example, in the case where the N-1 context has already been established between the base station 20 and the terminal 10, and then the Nth context is newly established between the base station 20 and the terminal 10. , A context having a high degree of similarity to the newly established Nth context may be selected from the already established N-1 contexts, and the selected context may be used as the reference context.

(Effect of proposal)
When establishing a new context, it is possible to reduce the overhead by not sending all the contexts to be established (that is, the new Ethernet Full Header) and referencing a context close to the content of the new context on the receiving side. Become.

For example, in the example of FIG. 10, the base station 20 transmits the Ethernet Full Header and the CID associated with the FH to the terminal 10 in step S203. On the other hand, in step S206, the base station 20 transmits an Ethernet Header that does not include "SOURCE ADDRESS" and an expanded CID of a size associated with the Ethernet Header. In this case, as shown in the example of FIG. 11, the CID of step S203 is 1 octet, whereas the CID of the expanded size of step S206 is 3 octets, but "SOURCE ADDRESS" is 6 octets. Therefore, the amount of information transmitted in step S206 is 3 octets less than the amount of information transmitted in step S203.

Further, as shown in FIG. 11, in the newly set context, the value of the "SOURCE ADDRESS" field and the value of the "DESTITION ADDRESS" field are the value of the "SOURCE ADDRESS" field and the "DESTITION ADDRESS" of the referenced context. If it is the same as the value of the field, an overhead reduction of 10 octets can be expected.

The compresor must continue to send the Ethernet Full Header until it receives feedback from the de-compressor. Therefore, it is considered that the effect of reducing the overhead becomes remarkable, especially when the wireless environment is bad.

(Modification example)
In the example of FIG. 9, whether or not to refer to the corresponding fields of the reference CID, "S", "D", "T / L", "TPID", "PCP", "CFI", and "VID". The flag indicating is set. However, for example, among the fields, the Type / Length field is considered to be static in many cases, and the “T / L” flag corresponding to the Type / Length field does not necessarily have to be set. Therefore, as a modification of the example of the extended CID field shown in FIG. 9, for example, an extended CID field including only the flag corresponding to the dynamic field can be considered. Hereinafter, some modifications to the example of the extended CID field shown in FIG. 9 will be shown.

Ethernet frame 802.1Q TAG is optional. Therefore, it is not necessary to include the 802.1Q TAG field in the extended CID field. FIG. 12 is a diagram showing an example in which the 802.1Q TAG field is not included in the extended CID field. In the example shown in FIG. 12, among the “S”, “D”, “T / L”, “TPID”, “PCP”, “CFI”, and “VID” shown in the example of FIG. 9, 802.1Q The "TPID", "PCP", "CFI", and "VID" corresponding to the TAG field are not included. In the case of a non-tagged frame, the extended CID field shown in FIG. 12 may be used instead of the example of the extended CID field shown in FIG.

FIG. 13 is a diagram showing an example of an extended CID field that can be used when the Ethernet frame contains 802.1Q TAG. Of the 802.1Q TAG subfields, "PCP" and "DEI" are considered to be dynamic, so the flag "PCP + DEI" is set in the extended CID field of FIG. VID is a flag of VLAN Identifier. Different VLAN Identifiers mean different Ethernet Devices. Assuming that the number of Ethernet devices: the number of controls = N: 1, one of S and D is the same as the value of the corresponding field in the context corresponding to the reference CID. For example, in the case of a downlink, the value in the "DESTITION ADDRESS" field is changed, so "D" is selected from "S / D". If it is an uplink, the value of the "SOURCE ADDRESS" field is changed, so "S" is selected from "S / D".

FIG. 14 is a diagram showing another example of the extended CID field that can be used when the Ethernet frame contains 802.1Q TAG. In the example of FIG. 13, the number of Ethernet devices: the number of controllers = N: 1 is assumed, but in the example of FIG. 14, the number of Ethernet devices: the number of controllers = N: N is assumed. Therefore, the "S" flag and the "D" flag are included.

FIG. 15 is a diagram showing an example of an extended CID field when the CID is 6 bits. When the CID is 6 bits, the number of remaining bits in the extended CID field is limited. Therefore, for example, as shown in the example of FIG. 15, only the "PCP" flag among various flags is displayed in the extended CID field. May be included.

FIG. 16 is a diagram showing another example of the extended CID field when the CID is 6 bits. As shown in FIG. 16, the extended CID field may include the “S / D” flag and the “VID + PCP + DEI” flag among various flags. Here, "VID + PCP + DEI" may be a flag set to the value 1 when any one of "VID", "PCP", and "DEI" is different.

FIG. 17 is a diagram showing an example of an extended CID field when the CID is 7 bits. In the example of the extended CID field of FIG. 17, there is no room for including the Reference CID flag bit. In this case, in addition to notifying whether the number of octets of the CID is 1 octet or 2 octets by RRC signaling, the necessity of reference CID may be notified by RRC signaling. Alternatively, as shown in the example of FIG. 18, RRC signaling may notify that the format of 1 octet of CID + 1 octet of reference CID is used.

In the above-described embodiment, an example in which the CID (extended CID field) is 1 octet has been described. However, the size of the CID is not limited to the above examples. For example, the size of the CID may be 2 octets. Generally, the bit length of the CID is equal to the bit length of the reference CID. Therefore, when the size of the CID is 2 octets, 8 bits are added to the CID, and 8 bits are added to the reference CID.

The order of each field in the extended CID field and the like is not limited to the above-described embodiment. Further, the order of the bits included in each field is not particularly limited.

As a modification of each of the above-described embodiments, the default context may be notified by RRC signaling, and thereafter, the operation of each embodiment may be performed using the context as a reference context.

(Device configuration)
Next, a functional configuration example of the terminal 10 and the base station 20 that execute the processing operations described so far will be described. The terminal 10 and the base station 20 have all the functions described in the present embodiment. However, the terminal 10 and the base station 20 may have only a part of all the functions described in the present embodiment.

<Terminal>
FIG. 19 is a diagram showing an example of the functional configuration of the terminal 10. As shown in FIG. 19, the terminal 10 has a transmitting unit 110, a receiving unit 120, and a control unit 130. The functional configuration shown in FIG. 19 is only an example. Any function classification and name of the functional unit may be used as long as the operation according to the present embodiment can be executed.

The transmission unit 110 creates a transmission signal from the transmission data and wirelessly transmits the transmission signal. The receiving unit 120 wirelessly receives various signals and acquires a signal of a higher layer from the received signal of the physical layer. Further, the receiving unit 120 includes a measuring unit that measures the received signal and acquires the received power and the like.

The control unit 130 controls the terminal 10. The function of the control unit 130 related to transmission may be included in the transmission unit 110, and the function of the control unit 130 related to reception may be included in the reception unit 120.

For example, in the transmission unit 110 of the terminal 10, when the first context for data communication is established and a second context for data communication is newly established, the second context An extended context identifier including an identifier and a flag indicating whether to refer to the first context as a reference context, and a part or all of the second context are transmitted to the base station 20. The receiving unit 120 of the terminal 10 receives the feedback corresponding to the second context from the base station 20. In response to the reception unit 120 receiving the feedback, the control unit 130 of the terminal 10 applies the compression header when transmitting the data.

For example, when the transmission unit 110 of the terminal 10 indicates that the flag indicating whether or not to refer to the first context as the reference context refers to the first context as the reference context, the transmission unit 110 may be set to the extended context identifier. A value that includes the identifier of the first context and is one or more fields of the second context, the same as the values set in the corresponding one or more fields of the first context, respectively. Is set, the context excluding one or more fields from the second context is transmitted to the base station 20. In addition, the transmission unit 110 of the terminal 10 may include in the extended context identifier the corresponding one or more flags indicating that one or more fields have been removed from the second context.

<Base station 20>
FIG. 20 is a diagram showing an example of the functional configuration of the base station 20. As shown in FIG. 20, the base station 20 includes a transmission unit 210, a reception unit 220, and a control unit 230. The functional configuration shown in FIG. 20 is only an example. Any function classification and name of the functional unit may be used as long as the operation according to the present embodiment can be executed.

The transmission unit 210 includes a function of generating a signal to be transmitted to the terminal 10 side and transmitting the signal wirelessly. The receiving unit 220 includes a function of receiving various signals transmitted from the terminal 10 and acquiring information of, for example, a higher layer from the received signals. Further, the receiving unit 220 includes a measuring unit that measures the received signal and acquires the received power and the like.

The control unit 230 controls the base station 20. The function of the control unit 230 related to transmission may be included in the transmission unit 210, and the function of the control unit 230 related to reception may be included in the reception unit 220.

For example, in the transmission unit 210 of the base station 20, when the first context for data communication is established and a second context for data communication is newly established, the second context is established. The extended context identifier, including the identifier of, and a flag indicating whether or not to refer to the first context as a reference context, and a part or all of the second context are transmitted to the terminal 10. The receiving unit 220 of the base station 20 receives the feedback corresponding to the second context from the terminal 10. In response to the reception unit 220 receiving the feedback, the control unit 230 of the base station 20 applies the compression header when transmitting the data.

For example, when the transmission unit 210 of the base station 20 indicates that the flag indicating whether or not to refer to the first context as the reference context indicates that the first context is referred to as the reference context, the extended context identifier is used. Contains the identifier of the first context and is one or more fields of the second context, the same as the values set in the corresponding one or more fields of the first context, respectively. A context in which one or more fields in which a value is set is excluded from the second context is transmitted to the terminal 10. In addition, the transmission unit 210 of the base station 20 may include the corresponding one or more flags indicating that the one or more fields have been removed from the second context in the extended context identifier.

<Hardware configuration>
The block diagrams (FIGS. 19 to 20) used in the description of the above-described embodiment show blocks of functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Further, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized by using one device that is physically or logically connected, or directly or indirectly (for example, by two or more devices that are physically or logically separated). , Wired, wireless, etc.) and may be realized using these plurality of devices. The functional block may be realized by combining the software with the one device or the plurality of devices. Functions include judgment, decision, judgment, calculation, calculation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, solution, selection, selection, establishment, comparison, assumption, expectation, and assumption. Broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, assigning, etc., but limited to these I can't. For example, a functional block (component) that functions transmission is called a transmitting unit or a transmitter. As described above, the method of realizing each of them is not particularly limited.

Further, for example, the terminal 10 and the base station 20 in one embodiment of the present invention may both function as computers that perform processing according to the present embodiment. FIG. 21 is a diagram showing an example of the hardware configuration of the terminal 10 and the base station 20 according to the present embodiment. The terminal 10 and the base station 20 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. ..

In the following explanation, the word "device" can be read as a circuit, device, unit, etc. The hardware configuration of the terminal 10 and the base station 20 may be configured to include one or more of the devices shown in 1001 to 1006 shown in the figure, or may be configured not to include some of the devices. May be good.

For each function of the terminal 10 and the base station 20, the processor 1001 performs calculations by loading predetermined software (programs) on hardware such as the processor 1001 and the memory 1002, and controls communication by the communication device 1004. It is realized by controlling at least one of reading and writing of data in the memory 1002 and the storage 1003.

Processor 1001 operates, for example, an operating system to control the entire computer. The processor 1001 may be configured by a central processing unit (CPU: Central Processing Unit) including an interface with a peripheral device, a control device, an arithmetic unit, a register, and the like.

Further, the processor 1001 reads a program (program code), a software module, data, etc. from at least one of the storage 1003 and the communication device 1004 into the memory 1002, and executes various processes according to these. As the program, a program that causes a computer to execute at least a part of the operations described in the above-described embodiment is used. For example, the control unit 130 of the terminal 10 may be realized by a control program stored in the memory 1002 and operating in the processor 1001, and may be realized in the same manner for other functional blocks. Although the above-mentioned various processes have been described as being executed by one processor 1001, they may be executed simultaneously or sequentially by two or more processors 1001. Processor 1001 may be implemented by one or more chips. The program may be transmitted from the network via a telecommunication line.

The memory 1002 is a computer-readable recording medium, and is composed of at least one such as a ROM (Read Only Memory), an EPROM (Erasable Programmable ROM), an EEPROM (Electrically Erasable Programmable ROM), and a RAM (Random Access Memory). May be done. The memory 1002 may be referred to as a register, a cache, a main memory (main storage device), or the like. The memory 1002 can store a program (program code), a software module, or the like that can be executed to implement the wireless communication method according to the embodiment of the present disclosure.

The storage 1003 is a computer-readable recording medium, and is, for example, an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, an optical magnetic disk (for example, a compact disk, a digital versatile disk, or a Blu-ray). It may consist of at least one (registered trademark) disk), smart card, flash memory (eg, card, stick, key drive), floppy (registered trademark) disk, magnetic strip, and the like. The storage 1003 may be referred to as an auxiliary storage device. The storage medium described above may be, for example, a database, server or other suitable medium containing at least one of the memory 1002 and the storage 1003.

The communication device 1004 is hardware (transmission / reception device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, a communication module, or the like. The communication device 1004 includes, for example, a high frequency switch, a duplexer, a filter, a frequency synthesizer, and the like in order to realize at least one of frequency division duplex (FDD: Frequency Division Duplex) and time division duplex (TDD: Time Division Duplex). It may be composed of. For example, the transmission unit 110, the reception unit 120, and the like described above may be realized by the communication device 1004. Further, the transmitting unit 110 and the receiving unit 120 may be physically or logically separated from each other.

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

Further, each device such as the processor 1001 and the memory 1002 is connected by the bus 1007 for communicating information. The bus 1007 may be configured by using a single bus, or may be configured by using a different bus for each device.

In addition, the terminal 10 and the base station 20 are hardware such as a microprocessor, a digital signal processor (DSP: Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), and an FPGA (Field Programmable Gate Array), respectively. It may be configured to include hardware, and a part or all of each functional block may be realized by the hardware. For example, processor 1001 may be implemented using at least one of these hardware.

(Summary of embodiments)
This specification discloses at least the following terminals and communication methods.

When the first context for data communication has been established and a second context for data communication is newly established, the identifier of the second context and the first context are used. An extended context identifier that includes a flag indicating whether or not to refer to it as a reference context, a transmitter that transmits a part or all of the second context, and feedback corresponding to the second context. A terminal including a receiving unit that receives the data and a control unit that applies a compression header when the data is transmitted in response to the receiving unit receiving the feedback.

According to the above configuration, when establishing a new context by including a flag in the extended context identifier to indicate whether to refer to an already established context, all the contexts that you want to establish (ie, the new one). By not transmitting Ethernet Full Header) and referencing a context close to the content of the new context on the receiving side, it is possible to reduce the overhead.

When the flag indicates that the first context is referred to as a reference context, the transmitter includes the identifier of the first context in the extended context identifier and of the second context. One or more of the fields, one or more of which are set to the same values set in the corresponding one or more fields of the first context, respectively. You may send the context excluded from the context of.

According to the above configuration, when the flag contained in the extended context identifier indicates that it refers to an already established context, the value is common to the already established context among the fields of the new context. By transmitting the context obtained by excluding the field that is, the overhead can be reduced.

The transmitter may include in the extended context identifier the corresponding one or more flags indicating that the one or more fields have been removed from the second context.

According to the above configuration, the receiving side can appropriately grasp the field to be referred to when referencing the content by checking the content of the flag.

When the first context for data communication has been established and a second context for data communication is newly established, the identifier of the second context and the first context are used. An extended context identifier that includes a flag indicating whether or not to refer to it as a reference context, a transmitter that transmits a part or all of the second context, and feedback corresponding to the second context. A base station comprising a receiving unit that receives the data and a control unit that applies a compression header when transmitting data in response to the receiving unit receiving the feedback.

When a first context for data communication has been established and a second context for data communication is newly established, the identifier of the second context and the first context are used. An extended context identifier that includes a flag indicating whether or not to refer to it as a reference context, a step of transmitting some or all of the second context, and feedback corresponding to the second context. A communication method by a terminal comprising a step of receiving and a step of applying a compressed header when transmitting data in response to receiving the feedback.

(Supplement to the embodiment)
Although the embodiments of the present invention have been described above, the disclosed inventions are not limited to such embodiments, and those skilled in the art can understand various modifications, modifications, alternatives, substitutions, and the like. There will be. Although explanations have been given using specific numerical examples in order to promote understanding of the invention, these numerical values are merely examples and any appropriate value may be used unless otherwise specified. The classification of items in the above description is not essential to the present invention, and items described in two or more items may be used in combination as necessary, and items described in one item may be used in combination with another item. It may be applied (as long as there is no contradiction) to the matters described in. The boundary of the functional unit or the processing unit in the functional block diagram does not always correspond to the boundary of the physical component. The operation of the plurality of functional units may be physically performed by one component, or the operation of one functional unit may be physically performed by a plurality of components. Regarding the processing procedure described in the embodiment, the processing order may be changed as long as there is no contradiction. For convenience of processing description, the terminal 10 and the base station 20 have been described with reference to functional block diagrams, but such devices may be implemented in hardware, software, or a combination thereof. The software operated by the processor of the terminal 10 according to the embodiment of the present invention and the software operated by the processor of the base station 20 according to the embodiment of the present invention are random access memory (RAM), flash memory, and read-only memory, respectively. It may be stored in (ROM), EPROM, EEPROM, registers, hard disk (HDD), removable disk, CD-ROM, database, server or any other suitable storage medium.

The notification of information is not limited to the mode / embodiment described in the present disclosure, and may be performed by using other methods. For example, information notification includes physical layer signaling (for example, DCI (Downlink Control Information), UCI (Uplink Control Information)), higher layer signaling (for example, RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, etc. It may be carried out by notification information (MIB (Master Information Block), SIB (System Information Block)), other signals, or a combination thereof. Further, the RRC signaling may be called an RRC message, and may be, for example, an RRC connection setup (RRC Connection Setup) message, an RRC connection reconfiguration (RRC Connection Reconfiguration) message, or the like.

Each aspect / embodiment described in the present disclosure includes LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), and 5G (5th generation mobile communication). system), FRA (Future Radio Access), NR (new Radio), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)) )), LTE 802.16 (WiMAX®), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth®, and other systems that utilize suitable systems and have been extended based on these. It may be applied to at least one of the next generation systems. Further, a plurality of systems may be applied in combination (for example, a combination of at least one of LTE and LTE-A and 5G).

The order of the processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in the present disclosure may be changed as long as there is no contradiction. For example, the methods described in the present disclosure present elements of various steps using exemplary order, and are not limited to the particular order presented.

In some cases, the specific operation performed by the base station 20 in the present disclosure may be performed by its upper node. In a network consisting of one or more network nodes having a base station 20, various operations performed for communication with a terminal are performed by the base station 20 and other network nodes other than the base station 20 (for example,). , MME, S-GW, etc., but not limited to these). Although the case where there is one network node other than the base station 20 is illustrated above, it may be a combination of a plurality of other network nodes (for example, MME and S-GW).

The input / output information and the like may be stored in a specific location (for example, memory) or may be managed using a management table. Input / output information and the like can be overwritten, updated, or added. The output information and the like may be deleted. The input information or the like may be transmitted to another device.

The determination may be made by a value represented by 1 bit (0 or 1), by a boolean value (Boolean: true or false), or by comparing numerical values (for example, a predetermined value). It may be done by comparison with the value).

Each aspect / embodiment described in the present disclosure may be used alone, in combination, or switched with execution. Further, the notification of predetermined information (for example, the notification of "being X") is not limited to the explicit one, but is performed implicitly (for example, the notification of the predetermined information is not performed). May be good.

Software, whether referred to as software, firmware, middleware, microcode, hardware description language, or other names, is an instruction, instruction set, code, code segment, program code, program, subprogram, software module. , Applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc. should be broadly interpreted.

Further, software, instructions, information, etc. may be transmitted and received via a transmission medium. For example, the software uses at least one of wired technology (coaxial cable, optical fiber cable, twisted pair, digital subscriber line (DSL: Digital Subscriber Line), etc.) and wireless technology (infrared, microwave, etc.) to create a website. When transmitted from a server, or other remote source, at least one of these wired and wireless technologies is included within the definition of transmission medium.

The information, signals, etc. described in this disclosure may be represented using any of a variety of different techniques. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description are voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any of these. It may be represented by a combination of.

Note that the terms explained in the present disclosure and the terms necessary for understanding the present disclosure may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may be a signal (signaling). Also, the signal may be a message. Further, the component carrier (CC: Component Carrier) may be referred to as a carrier frequency, a cell, a frequency carrier, or the like.

The terms "system" and "network" used in this disclosure are used interchangeably. In addition, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, relative values from predetermined values, or using other corresponding information. It may be represented. For example, the radio resource may be one indicated by an index.

The names used for the above parameters are not limited in any respect. Further, mathematical formulas and the like using these parameters may differ from those explicitly disclosed in this disclosure. Since the various channels (eg, PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, the various names assigned to these various channels and information elements are in any respect limited names. is not it.

In this disclosure, "base station (BS: Base Station)", "wireless base station", "fixed station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", " "Access point", "transmission point", "reception point", "transmission / reception point", "cell", "sector", "cell group", "cell group" Terms such as "carrier" and "component carrier" can be used interchangeably. Base stations are sometimes referred to by terms such as macrocells, small cells, femtocells, and picocells.

The base station can accommodate one or more (for example, three) cells. When a base station accommodates multiple cells, the entire coverage area of the base station can be divided into multiple smaller areas, each smaller area being a base station subsystem (eg, a small indoor base station (RRH:)). Communication services can also be provided by Remote Radio Head). The term "cell" or "sector" refers to part or all of the coverage area of at least one of the base stations and base station subsystems that provide communication services in this coverage. Point to.

In the present disclosure, terms such as "mobile station (MS: Mobile Station)", "user terminal", "user device (UE: User Equipment)", and "terminal" may be used interchangeably. ..

Mobile stations can be used by those skilled in the art as subscriber stations, mobile units, subscriber units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals, mobile terminals, wireless. It may also be referred to as a terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable term.

At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a communication device, or the like. At least one of the base station and the mobile station may be a device mounted on the mobile body, the mobile body itself, or the like. The moving body may be a vehicle (for example, a car, an airplane, etc.), an unmanned moving body (for example, a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned type). ) May be. It should be noted that at least one of the base station and the mobile station includes a device that does not necessarily move during communication operation. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

Further, the base station in the present disclosure may be read by the user terminal. For example, communication between a base station and a user terminal has been replaced with communication between a plurality of user terminals (for example, it may be referred to as D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.). Each aspect / embodiment of the present disclosure may be applied to the configuration. In this case, the terminal 10 may have the function of the base station 20 described above. In addition, words such as "up" and "down" may be read as words corresponding to communication between terminals (for example, "side"). For example, the upstream channel, the downstream channel, and the like may be read as a side channel. Similarly, the user terminal in the present disclosure may be read as a base station. In this case, the base station 20 may have the functions of the terminal 10 described above.

The terms "connected", "coupled", or any variation thereof, mean any direct or indirect connection or connection between two or more elements, and each other. It can include the presence of one or more intermediate elements between two "connected" or "combined" elements. The connections or connections between the elements may be physical, logical, or a combination thereof. For example, "connection" may be read as "access". As used in the present disclosure, the two elements use at least one of one or more wires, cables and printed electrical connections, and, as some non-limiting and non-comprehensive examples, the radio frequency domain. Can be considered to be "connected" or "coupled" to each other using electromagnetic energy having wavelengths in the microwave and light (both visible and invisible) regions.

The reference signal can also be abbreviated as RS (Reference Signal), and may be called a pilot depending on the applicable standard.

The phrase "based on" as used in this disclosure does not mean "based on" unless otherwise stated. In other words, the statement "based on" means both "based only" and "at least based on".

When used in the present disclosure are "include," "include," and variants thereof, these terms are as comprehensive as the term "comprising." Is intended. Furthermore, the term "or" used in the present disclosure is intended not to be an exclusive OR.

In the present disclosure, if articles are added by translation, for example, a, an and the in English, the disclosure may include that the nouns following these articles are plural.

In the present disclosure, the term "A and B are different" may mean "A and B are different from each other". The term may mean that "A and B are different from C". Terms such as "separate" and "combined" may be interpreted in the same way as "different".

Although the present invention has been described in detail above, it is clear to those skilled in the art that the present invention is not limited to the embodiments described in the present specification. The present invention can be implemented as modifications and modifications without departing from the spirit and scope of the invention as defined by the claims. Therefore, the description of the present specification is for the purpose of exemplification and does not have any limiting meaning to the present invention.

10 Terminal 110 Transmitter 120 Receiver 130 Control 20 Base station 210 Transmitter 220 Receiver 230 Control 1001 Processor 1002 Memory 1003 Storage 1004 Communication device 1005 Input device 1006 Output device

Claims

When the first context for data communication is established and a second context for data communication is newly established, the identifier of the second context and the first context are used. An extended context identifier that includes a flag indicating whether or not to refer to it as a reference context, and a transmitter that transmits a part or all of the second context.
A receiver that receives feedback corresponding to the second context, and
A control unit that applies a compression header when transmitting data in response to the receiving unit receiving the feedback.
A terminal equipped with.
When the flag indicates that the first context is referred to as a reference context, the transmitter includes the identifier of the first context in the extended context identifier and of the second context. One or more of the fields, one or more of which are set to the same values set in the corresponding one or more fields of the first context, respectively. Send the context removed from the context of
The terminal according to claim 1.
The transmitter includes a corresponding flag in the extended context identifier, indicating that the one or more fields have been removed from the second context.
The terminal according to claim 2.
When the first context for data communication is established and a second context for data communication is newly established, the identifier of the second context and the first context are used. An extended context identifier that includes a flag indicating whether or not to refer to it as a reference context, and a transmitter that transmits a part or all of the second context.
A receiver that receives feedback corresponding to the second context, and
A control unit that applies a compression header when transmitting data in response to the receiving unit receiving the feedback.
Base station with.
When the first context for data communication is established and a second context for data communication is newly established, the identifier of the second context and the first context are used. A flag indicating whether or not to refer as a reference context, an extended context identifier including, and a step of transmitting a part or all of the second context.
The step of receiving feedback corresponding to the second context,
In response to receiving the feedback, the step of applying the compressed header when sending the data,
Communication method by a terminal equipped with.