KR20180049423A - Apparatus and method of frequency resource allocation for NR(New Radio) - Google Patents

Abstract

Provided is a method for allocating frequency resources for fractional RB allocation, and more particularly, to a fractional RB allocation for minimizing control signaling overheads. The method comprises the steps of: setting an N value according to sub-carrier spacing; allocating upper or lower N subcarriers for uplink or downlink transmission and reception; and transmitting and receiving an uplink or a downlink.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method and an apparatus for allocating frequency resources for a next-

The present embodiments relate to a frequency resource allocation method for a next generation / 5G radio access network (hereinafter referred to as "NR [New Radio]") which has been discussed in 3GPP, .

In one embodiment, there is provided a method of allocating frequency resources for a next-generation radio access network, the method comprising: setting an N value according to sub-carrier spacing; setting N values for M sub- subcarriers for uplink or downlink transmission and reception, and transmitting and receiving uplink or downlink through an allocated subcarrier.

FIG. 1 shows an example of symbol level alignment among different SCS.
2 is a diagram showing fractional RB usage.
3 is a view showing a fractional RB format.
4 is a diagram illustrating a configuration of a base station according to another embodiment of the present invention.
5 is a diagram illustrating a configuration of a user terminal according to another embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Herein, the MTC terminal may mean a terminal supporting low cost (or low complexity) or a terminal supporting coverage enhancement. In this specification, the MTC terminal may mean a terminal supporting low cost (or low complexity) and coverage enhancement. Alternatively, the MTC terminal may refer to a terminal defined in a specific category for supporting low cost (or low complexity) and / or coverage enhancement.

In other words, the MTC terminal in this specification may mean a newly defined 3GPP Release-13 low cost (or low complexity) UE category / type for performing LTE-based MTC-related operations. Alternatively, the MTC terminal may support enhanced coverage over the existing LTE coverage or a UE category / type defined in the existing 3GPP Release-12 or lower that supports low power consumption, or a newly defined Release-13 low cost low complexity UE category / type.

The wireless communication system in the present invention is widely deployed to provide various communication services such as voice, packet data and the like. A wireless communication system includes a user equipment (UE) and a base station (BS, or eNB). The user terminal in this specification is a comprehensive concept of a terminal in wireless communication. It is a comprehensive concept which means a mobile station (MS), a user terminal (UT), an SS (User Equipment) (Subscriber Station), a wireless device, and the like.

A base station or a cell generally refers to a station that communicates with a user terminal and includes a Node-B, an evolved Node-B (eNB), a sector, a Site, a BTS A base transceiver system, an access point, a relay node, a remote radio head (RRH), a radio unit (RU), and a small cell.

That is, the base station or the cell in this specification is interpreted as a comprehensive meaning indicating a partial region or function covered by BSC (Base Station Controller) in CDMA, NodeB in WCDMA, eNB in LTE or sector (site) And covers various coverage areas such as megacell, macrocell, microcell, picocell, femtocell and relay node, RRH, RU, and small cell communication range.

Since the various cells listed above exist in the base station controlling each cell, the base station can be interpreted into two meanings. i) the device itself providing a megacell, macrocell, microcell, picocell, femtocell, small cell in relation to the wireless region, or ii) indicating the wireless region itself. i indicate to the base station all devices that are controlled by the same entity or that interact to configure the wireless region as a collaboration. An eNB, an RRH, an antenna, an RU, an LPN, a point, a transmission / reception point, a transmission point, a reception point, and the like are exemplary embodiments of a base station according to a configuration method of a radio area. ii) may indicate to the base station the wireless region itself that is to receive or transmit signals from the perspective of the user terminal or from a neighboring base station.

Therefore, a base station is collectively referred to as a base station, collectively referred to as a megacell, macrocell, microcell, picocell, femtocell, small cell, RRH, antenna, RU, low power node do.

Herein, the user terminal and the base station are used in a broad sense as the two transmitting and receiving subjects used to implement the technical or technical idea described in this specification, and are not limited by a specific term or word. The user terminal and the base station are used in a broad sense as two (uplink or downlink) transmitting and receiving subjects used to implement the technology or technical idea described in the present invention, and are not limited by a specific term or word. Here, an uplink (UL, or uplink) means a method of transmitting / receiving data to / from a base station by a user terminal, and a downlink (DL or downlink) .

There are no restrictions on multiple access schemes applied to wireless communication systems. Various multiple access schemes such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), OFDM-FDMA, OFDM- Can be used. An embodiment of the present invention can be applied to asynchronous wireless communication that evolves into LTE and LTE-advanced via GSM, WCDMA, and HSPA, and synchronous wireless communication that evolves into CDMA, CDMA-2000, and UMB. The present invention should not be construed as limited to or limited to a specific wireless communication field and should be construed as including all technical fields to which the idea of the present invention can be applied.

A TDD (Time Division Duplex) scheme in which uplink and downlink transmissions are transmitted using different time periods, or an FDD (Frequency Division Duplex) scheme in which they are transmitted using different frequencies can be used.

In systems such as LTE and LTE-advanced, a standard is constructed by configuring uplink and downlink based on a single carrier or carrier pair. The uplink and the downlink are divided into a Physical Downlink Control Channel (PDCCH), a Physical Control Format Indicator CHannel (PCFICH), a Physical Hybrid ARQ Indicator CHannel, a Physical Uplink Control CHannel (PUCCH), an Enhanced Physical Downlink Control Channel (EPDCCH) Transmits control information through the same control channel, and is configured with data channels such as PDSCH (Physical Downlink Shared CHannel) and PUSCH (Physical Uplink Shared CHannel), and transmits data.

On the other hand, control information can also be transmitted using EPDCCH (enhanced PDCCH or extended PDCCH).

In this specification, a cell refers to a component carrier having a coverage of a signal transmitted from a transmission point or a transmission point or transmission / reception point of a signal transmitted from a transmission / reception point, and a transmission / reception point itself .

The wireless communication system to which the embodiments are applied may be a coordinated multi-point transmission / reception system (CoMP system) or a coordinated multi-point transmission / reception system in which two or more transmission / reception points cooperatively transmit signals. antenna transmission system, or a cooperative multi-cell communication system. A CoMP system may include at least two multipoint transmit and receive points and terminals.

The multi-point transmission / reception point includes a base station or a macro cell (hereinafter referred to as 'eNB'), and at least one mobile station having a high transmission power or a low transmission power in a macro cell area, Lt; / RTI >

Hereinafter, a downlink refers to a communication or communication path from a multipoint transmission / reception point to a terminal, and an uplink refers to a communication or communication path from a terminal to a multiple transmission / reception point. In the downlink, a transmitter may be a part of a multipoint transmission / reception point, and a receiver may be a part of a terminal. In the uplink, the transmitter may be a part of the terminal, and the receiver may be a part of multiple transmission / reception points.

Hereinafter, a situation in which a signal is transmitted / received through a channel such as PUCCH, PUSCH, PDCCH, EPDCCH, and PDSCH is expressed as 'PUCCH, PUSCH, PDCCH, EPDCCH and PDSCH are transmitted and received'.

In the following description, an indication that a PDCCH is transmitted or received or a signal is transmitted or received via a PDCCH may be used to mean transmitting or receiving an EPDCCH or transmitting or receiving a signal through an EPDCCH.

That is, the physical downlink control channel described below may mean a PDCCH, an EPDCCH, or a PDCCH and an EPDCCH.

Also, for convenience of description, EPDCCH, which is an embodiment of the present invention, may be applied to the portion described with PDCCH, and EPDCCH may be applied to the portion described with EPDCCH according to an embodiment of the present invention.

Meanwhile, the High Layer Signaling described below includes RRC signaling for transmitting RRC information including RRC parameters.

The eNB performs downlink transmission to the UEs. The eNB includes a physical downlink shared channel (PDSCH) as a main physical channel for unicast transmission, downlink control information such as scheduling required for reception of PDSCH, and uplink data channel A physical downlink control channel (PDCCH) for transmitting scheduling grant information for transmission in a Physical Uplink Shared Channel (PUSCH). Hereinafter, the transmission / reception of a signal through each channel will be described in a form in which the corresponding channel is transmitted / received.

NR (New Radio)

3GPP recently approved the study item "Study on New Radio Access Technology" for research on next generation / 5G radio access technology, and based on this, RAN WG1 has frame structure, channel coding and modulation , waveform & multiple access scheme and so on. NR is required not only to improve the data transmission rate as compared with LTE, but also to design various requirements that are required according to granular and specific usage scenarios. In particular, enhancement mobile broadband (eMBB), massive MTC (MMTC) and URLLC (Ultra Reliable and Low Latency Communications) have been proposed as typical usage scenarios of NR. As a method to satisfy the requirements of each usage scenario, structure design is required. Specifically, eMBB, mMTC, and URLLC are considered as typical usage scenarios of NR that are being discussed in 3GPP. Since each usage scenario has different requirements for data rates, latency, coverage, etc., it is necessary to use different numerology (eg subcarrier) to efficiently satisfy the requirements of each usage scenario through frequency bands constituting an NR system there is a need for a method of effectively multiplexing a radio resource unit based on a space, a subframe, a TTI, etc.

One method is to support TDM, FDM, or TDM / FDM based multiplexing on a single NR carrier for numerology with different subcarrier spacing values, and to construct a scheduling unit in the time domain. The discussion on how to support the unit has been discussed. In this regard, NR is a type of time domain structure defined as a subframe. Reference numerology for defining the subframe duration is defined as 14 OFDM symbols of 15 kHz sub-carrier spacing (SCS) based normal CP overhead equivalent to LTE To define a single subframe duration. Thus, subframes in NR have a time duration of 1ms. However, unlike LTE, NR subframes are absolute reference time durations, and slots and mini-slots can be defined as time units that are the basis of actual uplink and downlink data scheduling. In this case, the number of OFDM symbols constituting the slot, y value is defined as y = 7 and 14 for the numerology having the SCS value of up to 60 kHz, and for the numerology having the SCS value larger than 60 kHz, y = Lt; / RTI >

Accordingly, any slot can be composed of 7 or 14 symbols, and all symbols are used for DL transmission according to the transmission direction of the corresponding slot, or all symbols are used for UL transmission, or the DL portion + (gap) + UL portion.

Also, a mini-slot composed of a smaller number of symbols than a corresponding slot is defined in an arbitrary numerology (or SCS), and a short-time time-domain scheduling interval is set for uplink / downlink data transmission or reception, A long-time time-domain scheduling interval for uplink / downlink data transmission and reception can be configured. Especially, in case of sending / receiving latency critical data such as URLLC, it is difficult to satisfy the latency requirement when scheduling is performed in 0.5 ms or 1 ms slot unit defined in a numerology based frame structure having a small SCS value such as 15 kHz Therefore, it is possible to define a mini-slot composed of a smaller number of OFDM symbols than the corresponding slot and to schedule the latency critical data such as the URLLC based on the defined mini-slot.

Alternatively, as described above, by supporting the numerology having different SCS values in one NR Carrier by multiplexing the TDM and / or FDM scheme, it is possible to reduce the number of slots based on the slot (or mini-slot) length defined for each numerology Scheduling of data according to latency requirement is also considered. For example, as shown in FIG. 1, when the SCS is 60 kHz, the symbol length is reduced to about 1/4 of that of the SCS 15 kHz. Therefore, when one slot is composed of 7 OFDM symbols, While the slot length based on 60 kHz is reduced to about 0.125 ms.

In this way, the NR is discussing how to satisfy the requirements of URLLC and eMBB by defining different SCSs or different TTI lengths.

[timing relationship between control and data for NR ]

According to the decision of the last 3GPP RAN1, NR is a method of determining HARQ ACK / NACK feedback timing according to downlink data reception of a UE, dynamically set by L1 signaling (eg DCI) or semi-statically Or a combination of higher layer and dynamic L1 signaling is being considered.

Also, as a method of determining the timing between UL assignment and UL data transmission according to this, it is also possible to set it dynamically by L1 signaling (eg DCI), semi-statically by higher layer, or combination of higher layer and dynamic L1 signaling Are being considered.

In addition, discussion has not been made through the 3GPP conference, but the DL assignment and accordingly the timing of receiving DL data are set dynamically by L1 signaling (eg DCI), semi-statically by higher layer, And dynamic L1 signaling may be considered.

Below is the contents of the 86bis Chair Note.

Agreements:

Timing relationship between DL data reception and corresponding acknowledgement can be (one or more of, FFS which ones)

Timing relationship between DL data reception and corresponding acknowledgment can be (one or more of FFS which ones)

- dynamically indicated by L1 signaling (e.g., DCI)

- Semi-statically indicated to a UE via higher layer

- a combination of indication by higher layers and dynamic L1 signaling (e.g., DCI)

FFS: minimum interval between DL data reception and corresponding acknowledgement

FFS: minimum interval between DL data reception and corresponding acknowledgment

FFS: common channels (e.g. random access)

FFS: common channels (eg random access)

Agreements:

Timing relationship between UL assignment and corresponding UL data transmission can be (one or more of, FFS which ones)

Timing relationship between UL assignment and corresponding UL data transmission can be (one or more of FFS which ones)

- dynamically indicated by L1 signaling (e.g., DCI)

- Semi-statically indicated to a UE via higher layer

- a combination of indication by higher layers and dynamic L1 signaling (e.g., DCI)

FFS: minimum interval between UL assignment and corresponding UL data transmission

FFS: minimum interval between UL assignment and corresponding UL data transmission

FFS: common channels (e.g. random access)

FFS: common channels (eg random access)

[Fractional RB  Usage]

According to the discussions of the last 3GPP RAN1 meeting, scenarios that require multiplexing between different numerologies, co-existence with LTE including NB-IoT, and guard band settings such as edge of system bandwidth can be dramatically increased compared to LTE.

Accordingly, when a guard band is set for each RB, efficient resource utilization may not be achieved in terms of resource efficiency. Therefore, a need for fractional RB usage is considered as shown in FIG.

When the fractional RB resource allocation for an arbitrary terminal is performed as described above, it is necessary to define a frequency resource allocation method for the corresponding fractional RB allocation. In this case, additional control signaling overhead may be added in addition to the conventional RB-based DCI configuration method.

The present invention proposes a frequency resource allocation method for fractional RB allocation. In particular, we propose a fractional RB allocation method that minimizes control signaling overhead.

Point 1: fractional PRB  Configuring format

Two fractional RB formats can be defined for any RB as shown in FIG. Specifically, for the 12 subcarriers constituting one RB, only the upper N subcarriers can be used for the uplink or downlink transmission and reception only for the format 1 and the lower N subcarriers usable for uplink or downlink transmission and reception. 2 can be defined.

In this case, the N value, which is the number of usable subcarriers (s) of the fractional RBs of format 1 and format 2, is an arbitrary natural number value satisfying 1 <= N <12 and defined as a single value according to each SCS value . In one embodiment of the present invention, a corresponding N value constituting a fractional RB format according to each SCS value may be defined as follows.

-------------------- Example of setting N value according to SCS ---------------------

SCS = 15kHz, no fractional RB supported

SCS = 30 kHz, format 1, format 2 fractional RB with N = 6

SCS = 60 kHz, format 1, format 2 fractional RB with N = 9

SCS = 120 kHz format 1, format 2 fractional RB with N = 10

SCS > 120 kHz, format 1, format 2 fractional RB with N = 11

-------------------------------------------------- --------------------

However, the above is only an example and all cases in which the N value for constructing the format 1 and format 2 fractional RB are determined as a function of SCS are included in the scope of the present invention.

Alternatively, the N value may be set by the base station by cell-specific or UE-specific RRC signaling as another way of defining the N value for fractional RB configuration of format 1 and format 2. In this case, the N values set by the base station for the format 1 and format 2 fractional RB configurations may be applied equally regardless of the SCS, or a different N value may be set by the base station depending on the SCS.

In addition, the corresponding N values for the fractional RB configuration based on format 1 and format 2 are not defined as a single value for each SCS or for all SCSs, but can be defined as a plurality of values. For example, for an SCS of 60 kHz, two values of N = 6 and 9 can be defined. The case where the corresponding N value for the fractional RB configuration based on each format 1 and format 2 has one or more candidate values for any SCS can also be included in the scope of the present invention.

Point 2. Fractional RB  How to allocate

Solution 1. Higher layer fractional RB  allocation without DCI  indication

Any cell / base station / network may be any NR carrier configured by the corresponding cell / base station / network via UE-specific / UE-specific higher layer signaling or broadcast DCI (i.e., cell-specific L1 signaling) RB allocation information having fractional RB usage based on the above format 1 or format 2 can be set and transmitted to the UE in the corresponding cell. In this case, the fractional RB allocation information is commonly applied to all UEs in the cell, and the corresponding fractional RB allocation information includes RB index (or indices) allocation information having the corresponding fractional RB usage, the format 1 based fractional RB The fractional RB format indication information indicating the format 2 based fractional RB, the numerology related setting information (eg, SCS value) of the corresponding RB, the N value setting related information, the relevant time interval related information And the like.

When the cell is set to the common fractional RB allocation by the cell / base station / network, any UE in the corresponding cell can perform UL assignment for the corresponding UE or corresponding UE for DL data transmission or DL data reception through the DL assignment DCI. When the RB allocation information including the fractional RBs is received, the set fractional RB can receive the uplink data or the downlink data only through the usable subcarrier (s).

Solution 2. DCI  Fractional through RB  indication method

It is possible to define that a fractional RB allocation is indicated through a UL assignment or a DL assignment DCI for an arbitrary UE in each NR cell / base station / network. Specifically, it is possible to define an information area for a fractional RB allocation in a UL assignment or a DL assignment DCI format for an arbitrary terminal.

As an example of the fractional RB allocation through the DCI, we construct an information area for the fractional RB allocation, and only the fractional RB allocation for the highest RB and the lowest RB among the RBs assigned through the UL assignment or the DL assignment DCI RB configuration is possible and can be indicated through the corresponding DCI. As an example of this, the fractional RB indication information area is composed of 2 bits, and 4 fractional RB setting information can be indicated according to the setting as follows.

'00' => no fractional RB

'01' => format 2 fractional RB for highest RB

'10' => format 1 fractional RB for lowest RB

'11' => format 2 fractional RB for highest RB and format 1 fractional RB for lowest RB

However, the mapping relationship between the set value of the information area and the corresponding fractional RB indication information is not limited to the above example, and the four fractional RB allocation information may be indicated through the corresponding fractional RB indication information of the DCI All cases fall within the scope of the present invention.

However, the fractional RB allocation can be limited to be applied only when contiguous RB allocation is performed for an arbitrary terminal.

In addition, if it is possible to set more than one value for the corresponding N value in the above fractional RB configuration, that is, the number of usable subcarriers (s) of the format 1 and format 2 fractional RBs is N1, N2, ..., Nm If the m values are configurable, the size of the fractional RB indication information area and the fractional RB indication case that can be indicated through it can be increased accordingly.

For example, when two values of N1 and N2 can be set as the number of usable subcarriers (s) in the format 1 and format 2 fractional RBs, the UL assignment or the fractional RB indication information field of the DL assignment DCI Can be composed of 3 bits, which allows the following seven fractional RB allocations.

000 => no fractional RB

001 => format 2 fractional RB for highest RB with N1 usable subcarriers

010 => format 2 fractional RB for highest RB with N2 usable subcarriers

011 => format 1 fractional RB for lowest RB with N1 usable subcarriers

100 => format 1 fractional RB for lowest RB with N2 usable subcarriers

101 => format 2 fractional RB for highest RB with N1 usable subcarriers and format 1 fractional RB for lowest RB with N1 usable subcarriers

110 => format 2 fractional RB for highest RB with N2 usable subcarriers and format 1 fractional RB for lowest RB with N2 usable subcarriers

111 => reserved

In this case, the mapping relationship between the set value of the information area and the fractional RB indication information is not limited to the above example, and the 7 fractional RB allocation information may be indicated through the corresponding fractional RB indication information of the DCI And all such cases are included in the scope of the present invention.

Alternatively, in the above example, the fractional RB indication information area of the UL assignment or DL assignment DCI may be composed of 4 bits, thereby allowing the following nine fractional RB allocation.

0000 => no fractional RB

0001 => format 2 fractional RB for highest RB with N1 usable subcarriers

0010 => format 2 fractional RB for highest RB with N2 usable subcarriers

0011 => format 1 fractional RB for lowest RB with N1 usable subcarriers

0100 => format 1 fractional RB for lowest RB with N2 usable subcarriers

0101 => format 2 fractional RB for highest RB with N1 usable subcarriers and format 1 fractional RB for lowest RB with N1 usable subcarriers

0110 => format 2 fractional RB for highest RB with N1 usable subcarriers and format 1 fractional RB for lowest RB with N2 usable subcarriers

0111 => format 2 fractional RB for highest RB with N2 usable subcarriers and format 1 fractional RB for lowest RB with N1 usable subcarriers

1000 => format 2 fractional RB for highest RB with N2 usable subcarriers and format 1 fractional RB for lowest RB with N2 usable subcarriers

1001 ~ 1111 => reserved

In this case, however, the mapping relationship between the set value of the information area and the fractional RB indication information is not limited to the above example, and the nine fractional RB allocation information may be indicated through the corresponding fractional RB indication information of the DCI And all such cases are included in the scope of the present invention.

Or, in the above example, the fractional RB allocation for a certain terminal can be limited to only one of the highest RB and the lowest RB. Accordingly, the fractional RB indication information area of the corresponding UL assignment or DL assignment DCI is composed of 3 bits, The following five settings can be defined.

000 => no fractional RB

001 => format 2 fractional RB for highest RB with N1 usable subcarriers

010 => format 2 fractional RB for highest RB with N2 usable subcarriers

011 => format 1 fractional RB for lowest RB with N1 usable subcarriers

100 => format 1 fractional RB for lowest RB with N2 usable subcarriers

However, in this case, the mapping relationship between the set value of the information area and the fractional RB indication information is not limited to the above example, and the five fractional RB allocation information may be indicated through the corresponding fractional RB indication information of the DCI And all such cases are included in the scope of the present invention.

Or a fractional RB indication and the number of usable subcarriers (s) (N1 vs. N2) in the corresponding fractional RB as separate information areas.

4 is a diagram illustrating a configuration of a base station according to another embodiment of the present invention.

Referring to FIG. 4, a base station 1000 according to another embodiment includes a control unit 1010, a transmission unit 1020, and a reception unit 1030.

The controller 1010 controls the overall operation of the base station 1000 according to the frequency resource allocation method for fractional RB allocation in the next generation radio access network according to the present invention described above.

The transmitting unit 1020 and the receiving unit 1030 are used to transmit and receive signals, messages, and data necessary for carrying out the present invention to and from the terminal.

5 is a diagram illustrating a configuration of a user terminal according to another embodiment of the present invention.

5, the user terminal 1100 according to another embodiment includes a receiving unit 1110, a control unit 1120, and a transmitting unit 1130.

The receiving unit 1110 receives downlink control information, data, and messages from the base station through the corresponding channel.

In addition, the controller 1120 controls the overall operation of the user terminal 1100 according to the frequency resource allocation method for fractional RB allocation in the next generation radio access network according to the present invention described above.

The transmitter 1130 transmits uplink control information, data, and a message to the base station through the corresponding channel.

The standard content or standard documents referred to in the above-mentioned embodiments constitute a part of this specification, for the sake of simplicity of description of the specification. Therefore, it is to be understood that the content of the above standard content and some of the standard documents is added to or contained in the scope of the present invention, as falling within the scope of the present invention.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims (1)

A frequency resource allocation method for a next generation radio access network,
Setting an N value according to sub-carrier spacing;
Allocating upper or lower N subcarriers for uplink or downlink transmission / reception to M subcarriers constituting one RB; And
And transmitting / receiving the uplink or the downlink through the allocated subcarrier.

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