WO2023065114A1

WO2023065114A1 - Apparatus and methods to perform uplinkdata compression in nr

Info

Publication number: WO2023065114A1
Application number: PCT/CN2021/124703
Authority: WO
Inventors: Yuanyuan Zhang; Chia-Chun Hsu
Original assignee: Mediatek Singapore Pte. Ltd.
Priority date: 2021-10-19
Filing date: 2021-10-19
Publication date: 2023-04-27
Also published as: CN115996426A

Abstract

Methods and apparatus to integrate uplink data compression (UDC) in NR are proposed. At the TX, UDC is performs first before packets routing and UL switching. At the RX, the receiver performs reordering before decompresses each UDC packet. UDC can be performed for a DRB, a SRB, a split bearer or a DAPS bearer.

Description

APPARATUS AND METHODS TO PERFORM UPLINKDATA COMPRESSION IN NR

TECHNICAL FIELD

The disclosed embodiments relate generally to wireless communication, and, more particularly, to data for Uplink Data Compression (UDC) transaction in NR.

BACKGROUND

Mobile data usage has been increasing at an exponential rate in recent year. Due to the steep increase in mobile traffic over the past years, there have been many attempts in finding new communication technologies to further improve the end-user experience and system performance of the mobile networks. The traffic growth has been mainly driven by the explosion in the number of connected devices, which are demanding more and more high-quality content that requires very high throughput rates.

Uplink data compression (UDC) is a method to improve uplink capacity by compressing uplink (UL) data. For UDC, many compression algorithms can be applied. For example, two different UDC compression algorithms are described in RFC1951 DEFLATE and RFC1950 ZLIB. UDC uses dictionary-based compression method. Up to now, UDC is introduced in LTE with limited usage. For example, UDC configuration is not applied to split RBs. However, it has not been supported in NR. In order to further improve the UE experience in NR, a method is desired to integrate UDC in NR with wide range of application, e.g. support of MRDC and split bearers. Considering the processes in NR protocol stack are different from LTE, the methods to support UDC in NR will be different from LTE.

SUMMARY

A method to integrate uplink data compression (UDC) in NR protocol stack is proposed. Specifically, At the TX, UDC is performs first before packets routing and UL switching. At the RX, the receiver performs reordering before decompresses each UDC packet.

In one embodiment, a transmitting device generates uplink data compression (UDC) compressed data packets and routs the data packets to the corresponding RLC bearer when the DRB is a split bearer. The receiving device stores and reorders the UDC compressed data packets. After that the receiving device decompresses those packets when delivering them to upper layer.

In one embodiment, a transmitting device configures two UDC protocol stacks when a DAPS bearer is configured. The transmitting device generates uplink data compression (UDC) compressed data packets and performs UDC with the target cell configuration when UL data switching is received from lower layer.

Other embodiments and advantages are described in the detailed description below. This summary does not purport to define the invention. The invention is defined by the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, where like numerals indicate like components, illustrate embodiments of the invention.

Figure 1 illustrates a mobile communication network 100 with a user equipment (UE) 101 and a base station 102 supporting uplink data compression (UDC) in accordance with embodiments of the current invention.

Figure 2 illustrates a simplified block diagram of a UE 201 supporting UDC in accordance with embodiments of the current invention.

Figure 3 illustrates an exemplary process flow for a UE to perform UDC for a normal or split bearer in accordance with embodiments of the current invention.

Figure 4 illustrates an exemplary process flow for a BS to perform UL data decompression for a normal or split bearer in accordance with embodiments of the current invention.

Figure 5 illustrates an exemplary process flow for a UE to perform UDC for a DAPS bearer in accordance with embodiments of the current invention.

Figure 6 illustrates an exemplary process flow for a BS to perform UL data decompression for a DAPS bearer in accordance with embodiments of the current invention.

Figure 7 is a flow chart of a method to perform UDC in from transmitter perspective in accordance with one novel aspect.

Figure 8 is a flow chart of a method to perform UL data decompression from receiver perspective in accordance with one novel aspect.

DETAILED DESCRIPTION

Reference will now be made in detail to some embodiments of the invention, examples of which are illustrated in the accompanying drawings.

Figure 1 illustrates a mobile communication network 100 with a user equipment (UE) 101 and a base station 102 supporting uplink data compression (UDC) in accordance with embodiments of the current invention. Wireless system 100 includes one or more fixed base infrastructure units forming a network distributed over a geographical region. The base unit may also be referred to as an access point, an access terminal, a base station, aNode-B, an eNode-B, a gNB, or by other terminology used in the art. UE 101 is configured with uplink data compression (UDC) to improve uplink capacity by compressing uplink (UL) data. UDC uses dictionary-based compression method. At the transmitter side, e.g., UE 101, the UDC compressor keeps processed uncompressed data in its compression memory 130; at the receiver side, e.g., BS 102, the UDC decompressor also keeps processed uncompressed data in its own compression memory 140.

In accordance with a novel aspect, a method to perform UDC in NR is proposed, which supports different MR-DC scenarios. To facilitate UDC transaction between transmitter and receiver, the following designs are considered: 1) procedure flow for processing compressed and uncompressed packets for both TX and RX; and 2) enable UDC for split bearer.

In the example of Figure 1, UE 101 is transmitting uplink data to be received by BS 102. At the TX side, application layer prepares data packets to be transmitted to BS 102 over lower layers. In PDCP layer 111, data packets are compressed by UDC, and compressed UDC packets 110 are transmitted over radio link control (RLC) layer 112. The transmission mode can be RLC AM or RLC UM. RLC layer packets is further transmitted over MAC layer 113 and PHY layer 114. At the RX side, BS 102 receives the data packets over PHY layer 124, MAC layer 123, RLC layer 122, and PDCP layer 121. BS 102 decompresses the compressed UDC packets 120 and deliver to higher application layer. In one embodiment, split bearer is configured for UE 101, which transmits UL data through two RLC bearers in UL.

Different layers apply different error handling schemes to ensure proper packet delivery. For example, PHY layer applies cyclic redundancy check (CRC) error detection and channel encoding/decoding, MAC layer applies Hybrid automatic repeat request (HARQ) forward error checking and ARQ error control, RLC layer applies ARQ which provides error correction by retransmission in AM. In PDCP layer, ifUDC is configured, then UDC layer error handling is applied through UDC checksum to maintain compression memory synchronization between TX and RX.

Figure 2 illustrates a simplified block diagram of a UE 201 supporting UDC in accordance with embodiments of the current invention. UE 201 has radio frequency (RF) transceiver module 213, coupled with antenna 214 receives RF signals from antenna 214, converts them to baseband signals and sends them to processor 212. RF transceiver 213 also converts received baseband signals from the processor 212, converts them to RF signals, and sends out to antenna 214. Processor 212 processes the received baseband signals and invokes different functional modules to perform features in UE 201. Memory 211 stores program instructions 215 and data to control the operations of UE 201. The program instructions and data 215, when executed by processor 212, enables UE 201 to carry out embodiments of the current invention. Suitable processors include, by way of example, a special purpose processor, a digital signal processor (DSP) , a plurality of microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, Application specific integrated circuits (ASICs) , Field programmable gate array (FPGAs) circuits, and other type of integrated circuit (IC) , and/or state machine.

UE 201 also includes multiple function modules and circuits that carry out different tasks in accordance with embodiments of the current invention. The functional modules and circuits can be implemented and configured by hardware, firmware, software, and any combination thereof. A processor in associated with software may be used to implement and configure features ofUE 201. In one embodiment, the functional modules and circuits 220 comprise an application or SDAP module 221 including a UDC layer entity 222 for UDC compression and decompression, a PDCP layer entity 223 for PDCP layer functionalities including ciphering, header compression, routing and reordering, an RLC layer entity 224, a MAC layer entity 225 with HARQ, and a PHY layer entity 226 supporting CRC and channel encoding/decoding.

In one example, Application module 221 prepares data packets to be compressed by UDC entity 222 to be passed to PDCP entity 223, and the compressed PDCP/UDC packets are transmitted over RLC bearer, which are then transmitted over MAC layer and PHY layer. Memory 211 comprises buffer 216 for storing a stream of uncompressed source packets and buffer 217 for storing a stream of UDC compressed packets. In addition, memory 221 comprises a UDC compression memory/buffer 218, which acts as a first in first out (FIFO) buffer. The input data of the UDC compression memory/buffer 218 is the stream of uncompressed packets, which is used for UDC checksum calculation. In one advantageous aspect, each UDC compressed packet is attached with a checksum. A receiver also maintains a UDC compression memory/buffer, which is used for deriving the checksum. The compression memory is synchronized initially between UE 201 and the receiver when UDC is configured. In one embodiment, UDC is configured for a split bearer, and the PDCP entity 223 is associated with two RLC bearers/

entities

224 and 234.

Figure 3 illustrates an exemplary process flow for a UE to perform UDC for a normal or split bearer in accordance with embodiments of the current invention. For a PDCP SDU received from upper layers, the transmitting PDCP entity associates the COUNT value corresponding to TX_NEXT to this PDCP SDU, performs UL data compression of the PDCP SDU using UDC, performs integrity protection, and ciphering, set the PDCP SN of the PDCP Data PDU, increment TX_NEXT by one, and submit the resulting PDCP Data PDU to lower layer. UE performs routing for the resulting PDCP Data PDU to the proper RLC entity when split bearer is configured.

Figure 4 illustrates an exemplary process flow for a BS to perform UL data decompression for a normal or split bearer in accordance with embodiments of the current invention. At reception of a PDCP Data PDU from lower layers, the receiving PDCP entity shall determine the COUNT value of the received PDCP Data PDU. After that, it performs deciphering and integrity verification of the PDCP Data PDU. Then the receiving PDCP entity performs reordering for the stored PDCP SDUs. Finally, it performs UL data decompression when delivering the PDCP SDUs to upper layers.

Figure 5 illustrates an exemplary process flow for a UE to perform UDC for a DAPS bearer in accordance with embodiments of the current invention. For DAPS bearers, the PDCP entity is configured with two sets of UDC protocols. When upper layers request uplink data switching, the transmitting PDCP entity shall perform UDC of the PDCP SDU using UDC configuration of the target cell and deliver the resulting PDCP Data PDU to target cell.

Figure 6 illustrates an exemplary process flow for a BS to perform UL data decompression for a DAPS bearer in accordance with embodiments of the current invention. For DAPS bearers, the PDCP entity is configured with two sets of UDC protocols. For DAPS bearers, the PDCP entity is configured with two sets of UDC protocols. The receiving PDCP entity performs PDCP reordering before UDC decompression. When upper layers request uplink data switching, the receiving PDCP entity shall perform UDC decompression of the PDCP SDU using UDC configuration of the target cell and deliver the resulting PDCP SDUs to upper layer.

Figure 7 is a flow chart of a method to perform UDC in from transmitter perspective in accordance with one novel aspect. In step 701, a transmitting device receives data packets from upper layer e.g. application layer or SDAP layer. In step 702, a transmitting device generates uplink data compression (UDC) compressed data packets. Each corresponding uncompressed data packet is pushed into a UDC compression buffer. In step 703, the device routs and submits the the UDC compressed data packets to lower layer.

Figure 8 is a flow chart of a method to perform UL data decompression from receiver perspective in accordance with one novel aspect. In step 801, a receiving device receives uplink data compression (UDC) compressed data packets. In step 802, the device stores and reorders the UDC compressed data packets. In step 803, the device decompresses the UDC compressed data packets when deliver the packets to upper layer.

Although the present invention has been described in connection with certain specific embodiments for instructional purposes, the present invention is not limited thereto. Accordingly, various modifications, adaptations, and combinations of various features of the described embodiments can be practiced without departing from the scope of the invention as set forth in the claims.

Claims

A method comprising:

generating uplink data compression (UDC) compressed data packets for a radio bearer by a transmitting device; and

routing the resulting data packets to a RLC bearer.
The method of Claim 1, wherein the radio bearer is a DRB, a SRB, or a split bearer.
The method of Claim 1, wherein the radio bearer is a DAPS bearer.
The method of Claim 3, wherein the transmitting device configures two sets of UDC and performs UDC with the target cell configuration when upper layers request uplink data switching.
A method comprising:

reordering uplink data compression (UDC) compressed data packets for a radio bearer by a receiving device from one or two RLC bearers; and

decompressing the uplink data compression (UDC) compressed data packets when deliver the data packets to upper layer.
The method of Claim 5, wherein the radio bearer is a DRB, a SRB, or a split bearer.
The method of Claim 5, wherein the radio bearer is a DAPS bearer.
The method of Claim 5, wherein the receiving device is the target cell, which performs UDC decompression with the target cell configuration when upper layers request uplink data switching.