KR20170109129A

KR20170109129A - LTE WLAN aggregation configuration methods and apparatus supporting high data rate WLAN

Info

Publication number: KR20170109129A
Application number: KR1020160032256A
Authority: KR
Inventors: 홍성표; 최우진
Original assignee: 주식회사 케이티
Priority date: 2016-03-17
Filing date: 2016-03-17
Publication date: 2017-09-28

Abstract

The present invention relates to an LWA configuration method and apparatus for supporting high-speed WLAN technology in an LTE-WLAN aggregation framework using base station radio resources and / or WLAN radio resources, thereby improving user throughput. In particular, the present invention provides a method for transmitting buffer size information by a terminal, comprising: calculating an L2 buffer size value based on an LWA bearer type, an uplink transmission path, and an uplink split; And transmitting the buffer size value to the base station through the terminal capability information or the RRC message.

Description

[0001] The present invention relates to a method and an apparatus for configuring an LWA supporting high-speed WLAN,

The present invention relates to an LWA configuration method and apparatus for supporting high-speed WLAN technology in an LTE-WLAN aggregation framework using base station radio resources and / or WLAN radio resources, thereby improving user throughput.

The present invention provides a method of transmitting buffer size information by a UE, the method comprising: calculating an L2 buffer size value based on an LWA bearer type, an uplink transmission path, and an uplink split; And transmitting the buffer size value to the base station through the terminal capability information or the RRC message.

1 is a schematic diagram of a LWA wireless protocol for a collocated scenario.
2 is a block diagram of a LWA wireless protocol for a non-collocated scenario.
FIG. 3 is a diagram illustrating LWA UE-EUTRA-Capability information elements and field descriptions.
4 is a diagram illustrating an example of the LWA UL layer 2 sturucture.
5 is a diagram illustrating a configuration of a base station according to another embodiment of the present invention.
6 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 numerals whenever 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 a transmission / reception point of a signal transmitted from a transmission / reception point, and the 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 a PDSCH, 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.

high speed WLAN Technology

The IEEE 802.11 specification, which provides WLAN technology, is also evolving continuously with the user's high-speed throughput requirements.

802.11ax increases frequency efficiency over the existing 802.11 technology in the 2.4GHz and 5GHz bands. To do this, we concentrate on dense deployment to provide scheduled uplinks and theoretically provide up to 9.6Gbps of throughput. In practical terms, it provides 1.6 Gbps.

802.11ad adds support for the 60 GHz millimeter waveband and delivers up to 7 Gbps.

802.11ay is in the process of improving 802.11ad and provides 20 Gbps speed.

Rel -13 LWA ( LTE - WLAN Aggregation)

In 3GPP Release 13, LWA for downlink data transmission using both base station and WLAN radio resources was standardized. The LWA has a different wireless protocol architecture depending on the LWA backhaul scenario and how the bearer is set up.

There are two bearer types for LWA as shown in FIG. 1 and FIG.

A separate LWA bearer represents a bearer where the radio protocol is present in both the base station and the WLAN in order to use both the base station radio resource and the WLAN radio resource.

- Switched LWA bearer represents a bearer where the wireless protocol is present in both the base station and the WLAN but uses only WLAN radio resources.

Figure 1 shows a LWA radio protocol architecture diagram for a collocated scenario. FIG. 2 shows a structure of a LWA radio protocol for a non-collocated scenario.

On the downlink, the LWA supports a split bearer operation in which the UE's PDCP sublayer supports in-sequence delivery of upper layer PDUs based on the reordering procedure introduced in dual connectivity. PDCP PDUs in the uplink are sent only through LTE.

Thus, in the Rel-13 LWA bearer, the split LWA bearer and the Switched LWA bearer constitute an LTE Layer 2 entity for uplink transmission to the UE in order to transmit PDCP PDUs on the uplink on the LTE. Therefore, when the terminal is configured with a switched LWA bearer as well as when the split LWA bearer is configured, the UE shall perform the reordering function (refer to Section 5.1.2.1.4 of TS 36.323) applied to the dual-connectivity split bearer specified in the PDCP standard (TS 36.323) ). When the reconfiguration of the Switched LWA (reconfiguration from the LTE bearer to the Switched LWA bearer or reconfiguration from the Switched LWA bearer to the LTE bearer) occurs, the UE reorders the PDUs transmitted out of order through the two paths, Could.

Rel -13 LWA Terminal Capability ( UE capability)

The LWA parameter UE capability is defined in FIG. 3 as a UE-EUTRA-Capability information element for Rel-13 LWA support.

For example, if the UE is instructed to support both lwa-r13 and lwa-splitbearer on the terminal capability parameter and the base station instructs the BS to support the split LWA bearer (in FIGS. 1 and 2) .

For example, if the base station instructs the base station to support lwa-r13 on the terminal capability parameter (or supports lwa-r13 but sets lwa-splitbearer to be unsupported), the base station It can be seen that the terminal supports switched LWA bearers (in FIG. 1 and FIG. 2).

In another example, when the UE is set to support lwa-BufferSize on the terminal capability parameter, the BS can know that the UE supports the increased L2 buffer size for the LWA and supports the dual-connectivity split bearer.

Thus, even if the terminal supports the increased L2 buffer size for LWA, it only supports buffer size for dual connectivity support based on LTE transmission rate. Accordingly, when using the above-described super-high-speed IEEE 802.11 technologies, a buffer size capable of supporting the corresponding transmission speed is not supported, thereby providing a speed that does not reach the maximum transmission speed.

As described above, in the conventional LWA technology, the UE can transmit data through the LWA irrespective of the IEEE 802.11 technology. However, there is a problem that sufficient high-speed throughput can not be provided for some high-speed 802.11 technologies due to buffer size limitation of the UE.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method and apparatus for efficiently supporting high-speed WLAN technology such as 802.11ax, 802.11ad, and 802.11ay to provide user throughput.

For the RRC Connected terminal, the base station must accurately recognize the terminal capability to provide a suitable configuration for the terminal. Normally, the MME stores UE capability, which consists of UE Radio Access Capability and UE Core Network Capability.

For example, the UE Core Network Capability can be indicated by the UE through NAS signaling (attach procedure, etc.). As another example, the UE Radio Access Capability can be transferred from the UE to the BS using the UE capability transfer procedure and transferred to the MME through the S1 interface. As another example, the UE Radio Access Capability may be indicated to the MME through the NAS signaling (attach procedure, etc.) by the UE and may be transmitted to the base station via the S1 interface.

If available, the MME transmits UE Radio Access Capability to the base station whenever the UE enters RRC Connected.

As described above, the LWA parameter UE capability is defined as a UE-EUTRA-Capability information element for Rel-13 LWA support as shown in FIG. Accordingly, it has been difficult to support the increased data rate of the high-speed WLAN when the LWA is configured using the high-speed WLAN technologies for the LWA-enabled terminal.

To solve this problem, the following methods can be used independently or in combination.

Increase L2 buffer size

In E-UTRA based on a single connection, the minimum L2 buffer size was taken into consideration for the RLC reordering delay. The minimum L2 buffer size is expressed by MaxDLDataRate * RoundTripTime + Max ULDataRate * RoundTripTime expression. By dividing this equation by 8.192, the bytes can be computed and quantized to the nearest value to obtain the minimum L2 buffer size. Here, the maximum downlink data rate / maximum uplink data rate represents the maximum number of maximum DL-SCH / UL-SCH transport block bits received / transmitted in the TTI according to each UE category, and the RLC round- Lt; / RTI >

With the introduction of Dual Connectivity (DC) in Rel-12, the L2 buffer size value for UEs supporting split bearer was further defined. The minimum L2 buffer size of a terminal supporting a DC split bearer considers the delay added when data is transmitted through SeNB in the above method. Therefore, the minimum L2 buffer size of the terminal supporting DC split bearer is MaxULDataRate * RTT + MaxDLDataRate_SeNB * RTT + MaxDLDataRate_MeNB * (RTT + X2 delay + Queuing in SeNB) The additional queuing was assumed to be 100 ms. Also, the maximum number of DL-SCH transport bits transmitted in one TTI allows the same distribution of MeNB and SeNB.

Rel-13 LWA adds capability to indicate that it supports larger values than the E-UTRA minimum L2 buffer size based on a single connection. Accordingly, the base station can recognize that the UE can support the L2 buffer size defined for the UE supporting the Rel-12 Dual Connectivity Split Bearer.

Larger L2 buffer size and terminal capability fields may be further defined to effectively support high-speed WLAN. First, various methods for calculating the L2 buffer size of a terminal capable of supporting high-speed WLAN will be described.

1) Split LWA Bearer L2 Buffer Size - LTE Uplink (Calculation of buffer size if the buffer size for the reordering buffers for LTE link transmission PDUs larger than the buffer size to a reordering buffer by a WLAN transmission link PDUs)

If the uplink data is transmitted to the LTE in the split LWA bearer operation, the uplink can be obtained by using the maximum number of UL-SCH transmission block bits transmitted by the UE as in the prior art. In other words, you can use MaxULDataRate_LTE * RoundTripTime.

The L2 buffer size due to the downlink transmission may be such that when the buffer size for buffering the LTE link transmission PDUs is larger than the buffer size for buffering WLAN link transmission PDUs for reordering (for example, PDUs It is possible to store the LTE link transmission PDUs during the WLAN delay to indicate that the buffer size is larger.) The L2 buffer can be obtained from MaxDLDataRate_LTE * (Xw delay + Queuing delay in WLAN + RTT in WLAN).

MaxDLDataRate_LTE can be calculated using the maximum number of the maximum DL-SCH transmission block bits to be transmitted.

Thus, for example, the final L2 buffer size can be obtained from the following equation.

MaxULDataRate_LTE * RoundTripTime (75ms) + MaxDLDataRate_LTE * (Xw delay + Queuing delay in WLAN + RTT in WLAN)

Or as another example, a buffer size for buffering PDUs that may be received via a WLAN may be added as follows.

MaxDLDataRate_LTE * RoundTripTime (75ms) + MaxDLDataRate_LTE * (Xw delay + Queuing delay in WLAN + RTT in WLAN) + MaxDLDataRate_WLAN * RTT in WLAN

MaxLDataRate_LTE * RoundTripTime (75ms) + MaxDLDataRate_LTE * (Xw delay + Queuing delay in WLAN + RTT in WLAN) + WLAN buffer size

MaxDLDataRate_WLAN can be obtained using the maximum number of bits supporting the WLAN downlink rate. Alternatively, MaxDLDataRate_WLAN can be obtained using the maximum number of bits supporting WLAN speed divided by 2 considering that the WLAN speed is provided in the uplink / downlink.

The WLAN buffer size may be used as it is, or the WLAN buffer size may be divided by 2 in consideration of the WLAN speed being provided in the uplink / downlink.

Currently, LWA and dual connectivity are not bundled together. Therefore, unlike dual connectivity, the maximum downlink data rate / maximum uplink data rate shall be such as to use the maximum number of maximum DL-SCH / UL-SCH transmission block bits received / transmitted within the TTI according to each UE category . RoundTripTime can be assumed to be RLC round trip time of 75 ms. Also, the X2 delay can be assumed to be 30ms, the same as the X2 delay. And the RTT in WLAN for retransmission in WLAN and WLAN can not be exactly assumed, but it can use smaller value than LTE base station.

To this end, the mobile station can transmit a new buffer size value calculated through the above to the base station through the terminal capability information or the RRC message. Or the terminal's (uplink / downlink / or total) WLAN rate / WLAN buffer size / high speed WLAN support / WLAN technology type to the base station through the terminal capability information or RRC message. Or the base station may receive the WLAN speed / WLAN technology type associated with the terminal through the WT.

The base station can transmit the LWA configuration including the corresponding indication information to the terminal based on the indicated information, and the terminal can apply the new configuration according to the wireless configuration according to the wireless configuration.

2) Split LWA Bearer L2 buffer size - LTE uplink (buffer size calculation method in the case where the buffer size to a reordering buffer by a WLAN transmission link PDUs larger than the buffer size to a reordering buffer by a WLAN transmission link PDUs)

If the split LWA bearer operation transmits uplink data to LTE,

The uplink can be obtained using the maximum number of UL-SCH transmission block bits transmitted by the UE in the same manner as in the prior art. In other words, you can use MaxULDataRate_LTE * RoundTripTime.

The L2 buffer size due to the downlink transmission is the maximum L2 buffer is MaxDLDataRate_WLAN * RoundTripTime (75ms) if the buffer size for buffering the WLAN link transmission PDUs is larger than the buffer size for reordering by buffering the LTE link transmission PDUs. .

MaxULDataRate_LTE * RoundTripTime (75ms) + MaxDLDataRate_WLAN * RoundTripTime (75ms)

Alternatively, as an example, the buffer size for buffering PDUs that may be received via LTE may be added as follows.

RoundTripTime (75ms) + MaxDLDataRate_LTE * RoundTripTime (75ms) + MaxDLDataRate_LTE * RoundTripTime (75ms)

Currently, LWA and dual connectivity are not bundled together. Therefore, unlike dual connectivity, when calculating the maximum downlink data rate / maximum uplink data rate, the maximum number of maximum DL-SCH / UL-SCH transmission block bits received / transmitted in the TTI according to each UE category Can be used. RoundTripTime can be assumed to be RLC round trip time of 75 ms.

For example, when the RTT in the WLAN for retransmission in the WLAN and the WLAN is several times smaller than the value (RTT) by the LTE base station and the speed (MaxDLDataRate_WLAN) of the high-speed WLAN is several times larger than the MaxDLDataRate_LTE, In order to support this, a high-speed WLAN speed can be specified, and 2) a minimum buffer size can be calculated using the equation.

As another example, the size of the L2 buffer of a terminal supporting high-speed WLAN can be calculated by the formula 1) and the maximum value of the equation 2).

3) Split LWA Bearer L2 buffer size - WLAN uplink (LTE link transmit the buffered PDUs in the reordering buffer size to the further method of calculating the size of the buffer is greater than the buffer size to a reordering buffer by a WLAN link for transmitting PDUs)

If the split LWA bearer operation transmits uplink data to the WLAN,

The uplink can be obtained using the maximum number of bits supporting the WLAN uplink rate. That is, MaxULDataRate_WLAN * RTT in WLAN. MaxULDataRate_WLAN can be obtained using the maximum number of bits supporting the WLAN uplink rate. Alternatively, MaxULDataRate_WLAN can be obtained using the maximum number of bits supporting WLAN speed divided by 2 considering WLAN speed is provided in the uplink / downlink.

The L2 buffer size due to the downlink transmission can be a value obtained from 1).

MaxULDataRate_WLAN * RTT in WLAN + MaxDLDataRate_LTE * (Xw delay + Queuing delay in WLAN + RTT in WLAN)

MaxDLDataRate_WLAN * RTT in WLAN + MaxDLDataRate_LTE * (Xw delay + Queuing delay in WLAN + RTT in WLAN) + MaxDLDataRate_WLAN * RTT in WLAN

MaxULDataRate_WLAN * RTT in WLAN + MaxDLDataRate_LTE * (Xw delay + Queuing delay in WLAN + RTT in WLAN) + WLAN buffer size

4) Split LWA Bearer L2 buffer size - WLAN link-up (buffer size calculation method in the case where the buffer size to a reordering buffer by a WLAN transmission link PDUs larger than the buffer size to a reordering buffer by a WLAN transmission link PDUs)

If the split LWA bearer operation transmits uplink data to the WLAN,

The L2 buffer size due to the downlink transmission can be a value obtained from 2).

MaxULDataRate_WLAN * RTT in WLAN + MaxDLDataRate_WLAN * RoundTripTime (75ms)

Or as another example, a buffer size for buffering PDUs that can be received via LTE in addition to the above equation.

RoundTripTime (75ms) + MaxDLDataRate_WLAN * RoundTripTime (75ms)

For example, when the RTT in the WLAN for retransmission in the WLAN and the WLAN is several times smaller than the value (RTT) by the LTE base station and the speed (MaxDLDataRate_WLAN) of the high-speed WLAN is several times larger than the MaxDLDataRate_LTE, In order to support, a high-speed WLAN speed can be specified, and 3) a minimum buffer size can be calculated using the equation.

As another example, the size of the L2 buffer of a terminal supporting high-speed WLAN can be calculated by the expression 3) and the maximum value of the expression 4).

5) Split LWA Bearer L2 buffer size - Split uplink (The method of calculating the size of the buffer is greater than the buffer size for the buffer size for the reordering buffers for LTE link transmit PDUs to the reordering buffers to the WLAN link transmission PDUs)

If the split LWA bearer operation separates and transmits uplink data using both LTE and WLAN at the same time,

The L2 buffer size due to the downlink transmission can be a value obtained from 1). The uplink can be obtained by considering the WLAN delay for the LTE uplink rate similarly to the downlink transmission.

Therefore, if the buffer size for buffering LTE link transmission PDUs and reordering is larger, the minimum L2 buffer can be obtained by the following equation.

MaxULDataRate_LTE * (Xw delay + Queuing delay in WLAN + RTT in WLAN)

MaxDLDataRate_LTE * (Xw delay + Queuing delay in WLAN + RTT in WLAN)

Alternatively, in addition to the above equation, a buffer size for buffering the PDUs that can be transmitted via the WLAN and / or a buffer size for buffering the PDUs that can be received via the WLAN may be added. For example, if both transmission and reception are included,

MaxULDataRate_LTE * (Xw delay + Queuing delay in WLAN + RTT in WLAN)

MaxDLDataRate_LTE * (Xw delay + Queuing delay in WLAN + RTT in WLAN)

+ MaxULDataRate_WLAN * RTT in WLAN + MaxDLDataRate_WLAN * RTT in WLAN

MaxULDataRate_LTE * (Xw delay + Queuing delay in WLAN + RTT in WLAN)

MaxDLDataRate_LTE * (Xw delay + Queuing delay in WLAN + RTT in WLAN)

+ WLAN buffer size + WLAN buffer size

Currently, LWA and dual connectivity are not bundled together. Therefore, unlike dual connectivity, when calculating the maximum downlink data rate / maximum uplink data rate, the maximum number of maximum DL-SCH / UL-SCH transmission block bits received / transmitted in the TTI according to each UE category Can be used.

6) Split LWA Bearer L2 buffer size - Split uplink (buffer size calculation method in the case where the buffer size to a reordering buffer by a WLAN transmission link PDUs larger than the buffer size to a reordering buffer by a WLAN transmission link PDUs)

The L2 buffer size due to the downlink transmission can be a value obtained from 2). The uplink can be obtained by considering the LTE delay for the WLAN uplink rate similarly to the downlink transmission.

Therefore, if the buffer size for buffering WLAN link transmission PDUs and reordering is larger, the minimum L2 buffer can be obtained as follows.

MaxULDataRate_WLAN * RoundTripTime (75ms) + MaxDLDataRate_WLAN * RoundTripTime (75ms)

Alternatively, in addition to the above equation, a buffer size for buffering PDUs that can be transmitted via LTE and / or a buffer size for buffering PDUs that can be received via LTE may be added. For example, if both transmission and reception are included,

RoundTripTime (75ms) + MaxDLDataRate_WLAN * RoundTripTime (75ms) + MaxDLDataRate_WLAN * RoundTripTime (75ms) + MaxDLDataRate_WLAN *

For example, when the RTT in the WLAN for retransmission in the WLAN and the WLAN is several times smaller than the value (RTT) by the LTE base station and the speed (MaxDLDataRate_WLAN) of the high-speed WLAN is several times larger than the MaxDLDataRate_LTE, In order to support this, a high-speed WLAN speed can be specified and a minimum buffer size can be calculated using the equation (6).

As another example, the size of the L2 buffer of a terminal supporting high-speed WLAN can be calculated by the equation 5) and the maximum value of the equation 6).

As another example, the L2 buffer size of a terminal supporting LWA split bearer can be calculated from the maximum value of 1), 2), 3), 4), 5), and 6).

7) Switched LWA Bearer L2 Buffer Size - LTE Uplink

In case of transmitting uplink data to LTE in Switched LWA bearer operation, the minimum L2 buffer can be obtained as follows.

MaxULDataRate_LTE * RoundTripTime (75ms) + MaxDLDataRate_WLAN * RTT in WLAN

Or by adding an additional value to support the transient reordering or (PDCP) reset in addition to the above equation.

For example, for high-speed WLANs up to 7 Gbps, the current high-speed UE (eg, Cat5 or Cat6 or higher UE) will only fit the L2 buffer size provided by the split bearer if the RTT in the WLAN is less than one- .

Therefore, when instructing the base station through the above-described methods (RRC or UE capability) that the terminal supports high-speed WLAN for high-speed WLAN support, the terminal adds information indicating that it does not support reordering, As shown in FIG.

Unlike LTE, a typical RTT in a WLAN may be much smaller, but the RTT may be long due to collisions in the WLAN attribute, so that there may be cases where the RTT can not be used only with a small value less than 1/20. Accordingly, the terminal can receive information indicating a Switched LWA bearer that does not support reordering and configure it for a new LWA bearer or a high-speed WLAN supporting terminal that does not support reordering for a high-speed WLAN supporting terminal .

8) Switched LWA bearer L2 buffer size - WLAN uplink

When transmitting uplink data to the WLAN in the Switched LWA bearer operation, the minimum L2 buffer can be obtained by the following equation.

MaxULDataRate_WLAN * RTT in WLAN + MaxDLDataRate_WLAN * RTT in WLAN

9) Switched LWA bearer L2 buffer size - split uplink

When the uplink data is separately transmitted in the Switched LWA bearer operation using both LTE and WLAN simultaneously, the minimum L2 buffer can be obtained by the following equation.

MaxULDataRate_LTE * (Xw delay + Queuing delay in WLAN + RTT in WLAN) +

MaxDLDataRate_LTE * RoundTripTime (75ms)

or

MaxLDataRate_LTE * RoundTripTime (75ms) + MaxULDataRate_LTE * (Xw delay + Queuing delay in WLAN + RTT in WLAN)

or

RoundTripTime (75ms) + MaxDLDataRate_WLAN * RoundTripTime (75ms) + MaxDLDataRate_LTE * RoundTripTime (75ms) + MaxDLDataRate_WLAN *

or

MaxLDataRate_LTE * RoundTripTime (75ms) + MaxULDataRate_WLAN * RoundTripTime (75ms) + MaxDLDataRate_LTE * RoundTripTime (75ms)

Can be used.

10) A method of calculating the maximum value obtained through the methods described above as the L2 buffer size

Alternatively, the maximum value obtained through the above-described methods can be calculated as the L2 buffer size.

To this end, the mobile station can transmit a new buffer size value calculated through the above to the base station through the terminal capability information or the RRC message. Or the terminal's (uplink / downlink / or total) WLAN rate / WLAN buffer size / high speed WLAN support / WLAN technology type to the base station through the terminal capability information or RRC message. Or the base station may receive the WLAN speed / WLAN technology type associated with the terminal through the WT. The base station can transmit the LWA configuration including the corresponding indication information to the terminal based on the indicated information, and the terminal can apply the new configuration according to the wireless configuration according to the wireless configuration.

As described above, in order to sufficiently support high-speed WLAN transmission, it is necessary to support a larger buffer size than the conventional Rel-13 LWA buffer size. In this case, in order to calculate the L2 buffer size of the high-speed WLAN supporting terminal, it may be calculated based on the LWA bearer type, the uplink transmission path, and the uplink split, or the maximum value of the calculated value may be used.

As another example, if a buffer size for a conventional Rel-13 LWA terminal is to be used for a high speed WLAN supporting terminal, or if a relatively small additional buffer size is to be provided for a high speed WLAN supporting terminal, LWA bearers and LWA bearers that provide other specific functions. For example, a new bearer can be defined to support high-speed WLAN with a small buffer size without using split bearer reordering function by limiting to a switched LWA bearer or processing data directly with the IP layer in the LWAAP entity, for example. Limited or to a bearer capable of delivering user data through the PDCP processing with some of the PDCP functions removed from the LWA bearer to avoid providing splitting / routing / separation and reordering functions in the PDCP for the switched LWA bearer .

In order to construct the LWA bearer by effectively utilizing the throughput of the terminal supporting the high-speed WLAN technology, the base station can recognize whether the terminal supports the high-speed WLAN technology, the wireless state information of the high-speed WLAN and the L2 buffer size .

For example, a new field that is distinguished from the lwa-BufferSize field described above may be defined as a terminal capability field, thereby indicating to the base station that the terminal supports a larger buffer size that supports high-speed WLAN technology.

In another example, the update field (lwa-SplitBearer-r14) in the above-described lwa-SplitBearer-r13 may indicate to the base station that the terminal supports a larger buffer size supporting high-speed WLAN technology.

Another example is the LWA switched bearer that does not support the new LWA bearer / reordering that supports high-speed WLAN (Switched LWA without WLAN bearer / split bearer reordering, distinct from the new Rel-13 LWA bearer type that supports high- Bearer / LWA bearer configured to not use some of the PDCP functions for high-speed WLAN data transmission / LWA bearer / LWAAP entity that only transmits data over the WLAN at a time Do not use split bearer reordering by processing data directly with the IP layer LWA bearer (for convenience of description, hereinafter referred to as Switched LWA bearer which does not use the reordering function, this is for convenience of explanation only, and other terms can be used). And defines a terminal capability field indicating whether or not to support the size, The base station can be instructed to support a switched bearer / larger buffer size that does not support the new LWA bearer / reordering supporting high-speed WLAN technology.

In another example, a split LWA bearer or a switched LWA bearer may define additional information elements (fields) on the terminal capability parameters to indicate that the terminal supports uplink transmissions over the WLAN. For example, it is possible to define an information element for indicating uplink transmission using both an LTE radio resource and a WLAN radio resource through an uplink split (at the PDCP). An information element for instructing to support an uplink transmission using both an LTE radio resource and a WLAN radio resource through an uplink split (in PDCP) and an information element for instructing another example to support uplink transmission through a WLAN Can be defined. For another example (at PDCP), an information element may be defined to indicate that it supports uplink transmissions using WLAN radio resources. For a terminal that does not support uplink transmission using both LTE radio resources and WLAN radio resources through the uplink split, the BS selects one of uplink transmission through WLAN and uplink transmission through LTE, As shown in FIG.

For another example, for a Switched LWA bearer, the base station may instruct the terminal to select one of uplink transmission over the WLAN and uplink transmission over the LTE to configure the terminal. That is, as shown in FIG. 4, it is possible not to configure the uplink split for the Switched LWA bearer.

For another example, for a Switched LWA bearer that does not use the reordering function, the base station may instruct the terminal to select one of the uplink transmission through the WLAN and the uplink transmission via the LTE to configure the terminal. That is, as shown in FIG. 4, it is possible not to configure the uplink split for the Switched LWA bearer.

As another example, it is possible to support uplink transmission using both LTE radio resources and WLAN radio resources only for a terminal supporting lwa-SplitBearer (conventionally). Accordingly, the base station can instruct the terminal using the high-speed WLAN to select one of the uplink transmission through the WLAN and the uplink transmission through the LTE to configure the terminal.

4 is a diagram illustrating an example of the LWA UL layer 2 sturucture.

As another example, a buffer size for a switched bearer supporting a high-speed WLAN may be newly defined, and a terminal capability field for indicating the buffer size may be defined to indicate to the base station that the terminal supports a buffer size that supports high-speed WLAN technology.

According to the above-described embodiments, the base station can forward the LWA configuration including the corresponding instruction information to the terminal based on the instruction information received from the terminal, and the terminal can apply a new configuration according to the wireless configuration according to the wireless configuration have.

If the buffer size to support high-speed WLAN is extended, it may be increased by n bits (n is a natural number) in addition to the PDCP SN of 18 bits. In this case, the base station can instruct bearer configuration information to support high-speed WLAN.

Values for larger buffer sizes supporting high speed WLAN technology can be calculated using one of the methods described above. For example, it can be calculated by further considering whether or not the uplink is split.

For another example, when a high-speed WLAN rate is supported, a buffer size for reordering buffering LTE link transmission PDUs has a larger buffer size for buffering WLAN link transmission PDUs for reordering. Accordingly, in case of supporting a high-speed WLAN speed, in the case of a terminal, a method of obtaining an L2 buffer size using a method of buffering high-speed WLAN link transmission PDUs and using a reordering method (2 in the above-mentioned method), 4), 6), 8) You can use one. In the conventional dual connectivity, buffer size is calculated by buffering MeNB link transmission PDUs while waiting for PDUs delayed through SeNB since they are merged among the same base stations. However, since the WLAN transmission speed may be higher in LWA, high-speed WLAN speed is supported , It may be necessary to calculate the buffer size in such a manner as to buffer the WLAN link transmission PDUs.

Another example is a Switched LWA bearer that supports high-speed WLAN and / or a Switched LWA bearer that does not support reordering, and / or a terminal LWA bearer that supports high-speed WLAN technology Whether or not the buffer size of the corresponding Switched LWA bearer is supported). In this case, a value for a larger buffer size supporting high speed WLAN technology can be calculated using one of the methods described above.

As described above, the present invention can effectively support high-speed WLAN technology such as 802.11ax, 802.11ad, and 802.11ay to provide user throughput.

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

5, 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 base station 1010 to provide a method and apparatus for efficiently supporting high-speed WLAN technology such as 802.11ax, 802.11ad, and 802.11ay to perform the above-described present invention to provide user throughput. .

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.

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

6, a 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 can provide a method and an apparatus for efficiently supporting the high-speed WLAN technology such as 802.11ax, 802.11ad, and 802.11ay required to perform the present invention to provide user throughput. And controls the operation of the terminal.

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

A method for a terminal to transmit buffer size information,
Calculating an L2 buffer size value based on the LWA bearer type, the uplink transmission path, and the uplink split; And
And forwarding the buffer size value to the base station via terminal capability information or an RRC message.