WO2021035600A1

WO2021035600A1 - Early data transmission for downlink data

Info

Publication number: WO2021035600A1
Application number: PCT/CN2019/103204
Authority: WO
Inventors: Fei Lu; Yingjie HONG
Original assignee: Zte Corporation
Priority date: 2019-08-29
Filing date: 2019-08-29
Publication date: 2021-03-04
Also published as: CN114208316A

Abstract

Method, systems and devices for wireless communication. The method includes receiving, by an apparatus, a paging message. The paging message includes a mobile terminated-early data transmission (MT-EDT) indication. The apparatus includes a memory storing instructions and a processor in communication with the memory. The method includes sending, by the apparatus, the paging message to a user equipment (UE); and establishing, by the apparatus, a radio resource control (RRC) connection with the UE. The method includes receiving, by the apparatus, an end marker. In response to receiving the end marker, the method further includes triggering, by the apparatus, a suspend procedure of suspending the RRC connection with the UE.

Description

EARLY DATA TRANSMISSION FOR DOWNLINK DATA

TECHNICAL FIELD

The present disclosure is directed generally to wireless communications. Particularly, the present disclosure relates to methods for early data transmission for downlink data.

BACKGROUND

Wireless communication technologies are moving the world toward an increasingly connected and networked society. High-speed and low-latency wireless communications rely on efficient network resource management and allocation between user mobile stations and wireless access network nodes (including but not limited to wireless base stations) . A new generation network is expected to provide high speed, low latency, low power consumption, and ultra-reliable communication capabilities and fulfil the requirements from different industries and users. In order to fulfil the low latency and high reliability requirements for the existing network industry as well as support the new generation network service, early data transmission (EDT) attracts attention.

SUMMARY

This document relates to methods, systems, and devices for wireless communication, and more specifically, for early data transmission for downlink data.

In one embodiment, the present disclosure describes a method for wireless communication. The method includes receiving, by an apparatus, a paging message. The paging message includes a mobile terminated-early data transmission (MT-EDT) indication. The apparatus includes an evolved node B (eNodeB) in an evolved packet system (EPS) . The method includes sending, by the apparatus, the paging message to a user equipment (UE) ; and establishing, by the apparatus, a radio resource control (RRC) connection with the UE. The method includes receiving, by the apparatus, an end marker. In response to receiving the end marker, the method further includes triggering, by the apparatus, a suspend procedure of suspending the RRC connection with the UE.

In another embodiment, the present disclosure describes another method for wireless communication. The method includes receiving, by an apparatus, a paging message. The paging message includes a mobile terminated-early data transmission (MT-EDT) indication. The apparatus includes a new-generation radio access network (NG RAN) in a 5-generation (5G) network. The method includes sending, by the apparatus, the paging message to a user equipment (UE) ; and establishing, by the apparatus, a radio resource control (RRC) connection with the UE. The method includes receiving, by the apparatus, an end marker. In response to receiving the end marker, the method further includes triggering, by the apparatus, a suspend procedure of suspending the RRC connection with the UE.

In some other embodiments, an apparatus for wireless communication may include a memory storing instructions and a processing circuitry in communication with the memory. When the processing circuitry executes the instructions, the processing circuitry is configured to carry out the above methods.

In some other embodiments, a device for wireless communication may include a memory storing instructions and a processing circuitry in communication with the memory. When the processing circuitry executes the instructions, the processing circuitry is configured to carry out the above methods.

In some other embodiments, a computer-readable medium comprising instructions which, when executed by a computer, cause the computer to carry out the above methods.

The above and other aspects and their implementations are described in greater detail in the drawings, the descriptions, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of a wireless communication system include a base station, one or more wireless network node, and one or more user equipment.

FIG. 2 shows an example of a network node.

FIG. 3 shows an example of a user equipment.

FIG. 4 shows a diagram of a user equipment communicating with an evolved packet system (EPS) .

FIG. 5A shows a flow diagram of a method for wireless communication.

FIG. 5B shows a flow diagram of a method for wireless communication.

FIG. 5C shows a flow diagram of a method for wireless communication.

FIG. 5D shows a flow diagram of a method for wireless communication.

FIG. 5E shows a flow diagram of a method for wireless communication.

FIG. 5F shows a flow diagram of a method for wireless communication.

FIG. 5G shows a flow diagram of a method for wireless communication.

FIG. 5H shows a flow diagram of a method for wireless communication.

FIG. 5I shows a flow diagram of a method for wireless communication.

FIG. 6 shows a flow diagram of an exemplary embodiment for wireless communication.

FIG. 7 shows a diagram of a user equipment communicating with a 5-generation (5G) network.

FIG. 8A shows a flow diagram of a method for wireless communication.

FIG. 8B shows a flow diagram of a method for wireless communication.

FIG. 8C shows a flow diagram of a method for wireless communication.

FIG. 8D shows a flow diagram of a method for wireless communication.

FIG. 8E shows a flow diagram of a method for wireless communication.

FIG. 8F shows a flow diagram of a method for wireless communication.

FIG. 8G shows a flow diagram of a method for wireless communication.

FIG. 9 shows a flow diagram of an exemplary embodiment for wireless communication.

DETAILED DESCRIPTION

The present disclosure will now be described in detail hereinafter with reference to the accompanied drawings, which form a part of the present disclosure, and which show, by way of illustration, specific examples of embodiments. Please note that the present disclosure may, however, be embodied in a variety of different forms and, therefore, the covered or claimed subject matter is intended to be construed as not being limited to any of the embodiments to be set forth below.

Throughout the specification and claims, terms may have nuanced meanings suggested or implied in context beyond an explicitly stated meaning. Likewise, the phrase “in one embodiment” or “in some embodiments” as used herein does not necessarily refer to the same embodiment and the phrase “in another embodiment” or “in other embodiments” as used herein does not necessarily refer to a different embodiment. The phrase “in one implementation” or “in some implementations” as used herein does not necessarily refer to the same implementation and the phrase “in another implementation” or “in other implementations” as used herein does not necessarily refer to a different implementation. It is intended, for example, that claimed subject matter includes combinations of exemplary embodiments or implementations in whole or in part.

In general, terminology may be understood at least in part from usage in context. For example, terms, such as “and” , “or” , or “and/or, ” as used herein may include a variety of meanings that may depend at least in part upon the context in which such terms are used. Typically, “or” if used to associate a list, such as A, B or C, is intended to mean A, B, and C, here used in the inclusive sense, as well as A, B or C, here used in the exclusive sense. In addition, the term “one or more” or “at least one” as used herein, depending at least in part upon context, may be used to describe any feature, structure, or characteristic in a singular sense or may be used to describe combinations of features, structures or characteristics in a plural sense. Similarly, terms, such as “a” , “an” , or “the” , again, may be understood to convey a singular usage or to convey a plural usage, depending at least in part upon context. In addition, the term “based on” or “determined by” may be understood as not necessarily intended to convey an exclusive set of factors and may, instead, allow for existence of additional factors not necessarily expressly described, again, depending at least in part on context.

The present disclosure describes methods and devices for early data transmission (EDT) for downlink data. The present disclosure addresses the issues with existing methods during early data transmission for the downlink data. When a radio access network (RAN) receives downlink data and early data indication, the RAN may not know when to release or suspend a radio resource control (RRC) connection between the RAN and a user equipment (UE) .

One of the existing methods may use a timer to measure an inactive period which is a duration when the UE is inactive since its most recent activity. When the measure inactive period is longer than a pre-determined threshold, the RAN may decide to release or suspend the RRC connection between the RAN and the UE. There may be many problems associated with this method. For example, when the pre-determined threshold is relatively short (for example, 0.5 second) , the RRC connection may be released or suspended too early so that, when another need (e.g., early data transmission for second downlink data) arises, RRC connection need to be established or resume, leading to consumer latency issues and high battery consumption. For another example, when the pre-determined threshold is relatively long (for example, 5 seconds) , the RRC connection may stay connected or active too long without useful data transmission, leading to low-utilization of network resources and high battery consumption.

The present disclosure describes a method and a system for early data transmission. The present disclosure addresses at least some of the above problems by generating an end marker indicating the end of early transmission data for present downlink data. Upon receiving the end marker, the RAN may trigger a suspend procedure of suspending the RRC connection between the RAN and the UE. In another words, the end marker indicates that the early transmission data for downlink data ends, so that the RAN may release or suspend the RRC connection between the RAN and the UE at the proper times, improving overall system capacity and battery management.

5-generation (5G) network is expected to provide high speed, low latency and ultra-reliable communication capabilities and fulfil the requirements from different industries and users. In order to fulfil the low latency and high reliability requirements for the current network (4G network, LTE network, and evolved packet system (EPS) ) as well as support the new generation (e.g, 5G network) network, early data transmission may be used to lower latency and/or battery consumption.

To meet the more stringent requirements of a future generation network, early data transmission (EDT) may be used to reduce network latency. EDT is a feature that would allow opportunistic data transmission to a UE..

FIG. 1 shows a wireless communication system 100 including one or more wireless network node (132 and 134) and one or more user equipment (UE) (152, 154, and 156) . The wireless network node may be a base station, which may be an evolved nodeB (eNB, eNodeB, or NB) or a new-generation radio access network (NG RAN) in a mobile telecommunications context. Each of the UE may wirelessly communicate with the wireless network nodes via a plurality of radio channels 140. For example, a first UE 152 may wirelessly communicate with a first wireless network node 132 via a channel including a plurality of radio channels during a certain period of time, and the first UE 152 may also wirelessly communicate with a second wireless network node 134 via a channel including a plurality of radio channels during a certain period of time. Likewise, a second UE 154 and a third UE 156 may wirelessly communicate with the first and second wireless network nodes. The first wireless network node 132 and the second wireless network node 134 may communicate to each other via one or more channel 135.

In one implementation, referring to FIG. 1, the wireless communication system 100 may include a base station 110, which functions as a central unit. The base station 110 may communicate with one or more wireless network node via one or more channel 120.

Figure 2 shows an example base station 200. The example base station may include radio Tx/Rx circuitry 208 to receive and transmit with UEs and/or other base stations. The base station may also include network interface circuitry 209 to communicate the base station with other base stations and/or a core network, e.g., optical or wireline interconnects, Ethernet, and/or other data transmission mediums/protocols. The base station 200 may optionally include an input/output (I/O) interface 206 to communicate with an operator or the like.

The base station may also include system circuitry 204. System circuitry 204 may include processor (s) 221 and/or memory 222. Memory 222 may include an operating system 224, instructions 226, and parameters 228. Instructions 226 may be configured for the one or more of the processors 124 to perform the functions of the base station. The parameters 228 may include parameters to support execution of the instructions 226. For example, parameters may include network protocol settings, bandwidth parameters, radio frequency mapping assignments, and/or other parameters.

Figure 3 shows an example UE 300. The UE 300 may be a mobile device, for example, a smart phone. The UE 300 may include communication interfaces 302, a system circuitry 304, an input/output interfaces (I/O) 306, a display circuitry 308, and a storage 309. The display circuitry may include a user interface 310. The system circuitry 304 may include any combination of hardware, software, firmware, or other logic/circuitry. The system circuitry 304 may be implemented, for example, with one or more systems on a chip (SoC) , application specific integrated circuits (ASIC) , discrete analog and digital circuits, and other circuitry. The system circuitry 304 may be a part of the implementation of any desired functionality in the UE 300. In that regard, the system circuitry 304 may include logic that facilitates, as examples, decoding and playing music and video, e.g., MP3, MP4, MPEG, AVI, FLAC, AC3, or WAV decoding and playback; running applications; accepting user inputs; saving and retrieving application data; establishing, maintaining, and terminating cellular phone calls or data connections for, as one example, internet connectivity; establishing, maintaining, and terminating wireless network connections, Bluetooth connections, or other connections; and displaying relevant information on the user interface 310. The user interface 310 and the inputs/output (I/O) interfaces 306 may include a graphical user interface, touch sensitive display, haptic feedback or other haptic output, voice or facial recognition inputs, buttons, switches, speakers and other user interface elements. Additional examples of the I/O interfaces 306 may include microphones, video and still image cameras, temperature sensors, vibration sensors, rotation and orientation sensors, headset and microphone input /output jacks, Universal Serial Bus (USB) connectors, memory card slots, radiation sensors (e.g., IR sensors) , and other types of inputs.

Referring to FIG. 3, the communication interfaces 302 may include a Radio Frequency (RF) transmit (Tx) and receive (Rx) circuitry 316 which handles transmission and reception of signals through one or more antennas 314. The communication interface 302 may include one or more transceivers. The transceivers may be wireless transceivers that include modulation /demodulation circuitry, digital to analog converters (DACs) , shaping tables, analog to digital converters (ADCs) , filters, waveform shapers, filters, pre-amplifiers, power amplifiers and/or other logic for transmitting and receiving through one or more antennas, or (for some devices) through a physical (e.g., wireline) medium. The transmitted and received signals may adhere to any of a diverse array of formats, protocols, modulations (e.g., QPSK, 16-QAM, 64-QAM, or 256-QAM) , frequency channels, bit rates, and encodings. As one specific example, the communication interfaces 302 may include transceivers that support transmission and reception under the 2G, 3G, BT, WiFi, Universal Mobile Telecommunications System (UMTS) , High Speed Packet Access (HSPA) +, and 4G /Long Term Evolution (LTE) standards. The techniques described below, however, are applicable to other wireless communications technologies whether arising from the 3rd Generation Partnership Project (3GPP) , GSM Association, 3GPP2, IEEE, or other partnerships or standards bodies.

Referring to FIG. 3, the system circuitry 304 may include one or more processors 321 and memories 322. The memory 322 stores, for example, an operating system 324, instructions 326, and parameters 328. The processor 321 is configured to execute the instructions 326 to carry out desired functionality for the UE 300. The parameters 328 may provide and specify configuration and operating options for the instructions 326. The memory 322 may also store any BT, WiFi, 3G, 4G, 5G or other data that the UE 300 will send, or has received, through the communication interfaces 302. In various implementations, a system power for the UE 300 may be supplied by a power storage device, such as a battery or a transformer.

Referring to FIG. 4, a user equipment (UE) 410 may communicate with an evolved packet system (EPS) 400. The UE may communicate with an evolved Node B (eNodeB) 420. The eNodeB 420 may communicate with a mobility management entity (MME) 430 via an interface S1-C. The MME 430 may perform at least one of the following functions: connection management, reachability management, mobility procedure Management, access authentication, and access authorization. The MME 430 may include a non-access stratum (NAS) security termination. The eNodeB 420 may also communicate with a serving gateway (SGW) 440 via an interface S1-U. The MME 430 may communicate with the SGW 440 via an interface S11. The SGW 440 may communicate with a packet data network (PDN) gateway (PGW) via an interface S5/S8.

Referring to FIG. 5A, the present disclosure describes a method 500 for early data transmission for downlink data. The method 500 may include at least one of: step 510: receiving, by an apparatus, a paging message; step 520: sending, by the apparatus, the paging message to a user equipment (UE) ; step 530: establishing, by the apparatus, a radio resource control (RRC) connection with the UE; step 540: receiving, by the apparatus, an end marker; and step 550: in response to receiving the end marker, triggering, by the apparatus, a suspend procedure of suspending the RRC connection with the UE.

In step 510, the method 500 may include receiving, by an apparatus, a paging message. The apparatus may include a memory storing instructions and a processor in communication with the memory. The paging message comprising a mobile terminated-early data transmission (MT-EDT) indication. In one implementation, the apparatus may include an evolved node B (eNodeB) , and the method 500 may include receiving, by the apparatus, the paging message from a mobility management entity (MME) .

Referring to FIG. 5B, in another implementation, before receiving, by the apparatus, the paging message, the method 500 may further include at least one of: step 501: in response to receiving downlink data, a packet data network gateway (PGW) sends the downlink data to a serving gateway (SGW) ; step 502: the SGW sends a downlink data notification to the MME, the downlink data notification comprising the MT-EDT indication; step 503: the MME sends a downlink data notification acknowledgment (ACK) to the SGW; and step 504: the MME sends the paging message to the apparatus.

In step 520, the method may include sending, by the apparatus, the paging message to a user equipment (UE) . In one implementation, after the eNodeB receives the paging message from the MME, the eNodeB may send the paging message with the EDT indication to the UE.

In step 530, the method may include establishing, by the apparatus, a radio resource control (RRC) connection with the UE. Referring to FIG. 5C, in one implementation, the step 530 may include at least one of: step 531: receiving, by the apparatus, a random access preamble from the UE; step 532: sending, by the apparatus, a random access response to the UE; and step 533: receiving, by the apparatus, a RRC connection resume request from the UE.

Referring to FIG. 5D, in another implementation, the step 530 may further include at least one of the following: step 534: in response to establishing the RRC connection with the UE, the apparatus send an UE context resume request to the MME, so that the MME enters a connected state (e.g., an EPS connection management-connected (ECM-CONNECTED) state) ; step 535: the MME sends a modify bearer request message to the SGW, the modify bearer request message comprises a downlink tunnel endpoint identifier (TEID) and an internet protocol (IP) address of the apparatus; and step 536: the SGW sends a modify bearer response message to the MME.

In step 540, the method may include receiving, by the apparatus, an end marker. The step 540 may include receiving, by the apparatus, a portion or all of the downlink data from the SGW; and sending, by the apparatus, a RRC connection release message to the UE, the RRC connection release message including the portion or all of the downlink data.

The end marker may contains a marker indicating the end of transmitting downlink data. The end marker may include a special signal or special sequence to indicate an end of downlink data. In one implementation, the end marker may include at least one of: a general packet radio service (GPRS) tunneling protocol-user plane (GTP-U) message with a defined message identity, or a user data packet with a defined GTP-U header.

In one implementation, an end marker may be initiated by the SGW, and the end marker is transmitted together with a last packet of the downlink data from the SGW to the apparatus (e.g., eNodeB) . For example, the end marker may be disposed at the end of the last packet of the downlink data. Referring to FIG. 5E, the step 540 may include at least one of: step 542-1: receiving, by the apparatus, a last packet of the downlink data together with the end marker from the SGW; and step 544-1: sending, by the apparatus, a RRC connection release message to the UE, the RRC connection release message comprising the last packet of the downlink data.

In another implementation, an end marker may be initiated by the SGW, and the end marker is transmitted separately from a last packet of the downlink data from the SGW to the apparatus (e.g., eNodeB) . For example, the SGW may send the last packet of the downlink data to the eNodeB, and then, the SGW may separately send the end marker to the eNodeB. Referring to FIG. 5F, the step 540 may include at least one of: step 542-2: receiving, by the apparatus, a last packet of the downlink data from the SGW; step 542-4: receiving separately, by the apparatus, the end marker from the SGW; and step 542-6: sending, by the apparatus, a RRC connection release message to the UE, the RRC connection release message comprising the last packet of the downlink data.

In another implementation, an end marker may be initiated by the PGW, the end marker is transmitted from the PGW to the SGW, and then the end marker is transmitted together with a last patch of the downlink data from the SGW to the apparatus (e.g., eNodeB) . Referring to FIG. 5G, the step 540 may include at least one of: step 542-3: generating, by the PGW, the end marker in response to an end of the downlink data; step 544-3: sending the end marker from the PGW to the SGW; step 546-3: receiving, by the apparatus, a last packet of the downlink data together with the end marker from the SGW; and step 548-3: sending, by the apparatus, a RRC connection release message to the UE, the RRC connection release message comprising the last packet of the downlink data.

In another implementation, an end marker may be initiated by the PGW, the end marker is transmitted from the PGW to the SGW, and then the end marker is transmitted separately from a last patch of the downlink data from the SGW to the apparatus (e.g., eNodeB) . Referring to FIG. 5H, the step 540 may include at least one of: step 542-4: generating, by the PGW, the end marker in response to an end of the downlink data; step 544-4: sending the end marker from the PGW to the SGW; step 546-4: receiving, by the apparatus, a last packet of the downlink data from the SGW; step 548-4: receiving separately, by the apparatus, the end marker from the SGW; and step 549-4: sending, by the apparatus, a RRC connection release message to the UE, the RRC connection release message comprising the last packet of the downlink data.

In step 550, the method 500 may include in response to receiving the end marker, triggering, by the apparatus, a suspend procedure of suspending the RRC connection with the UE. In response to triggering the suspend procedure, the method may further include sending, by the apparatus, a suspend indication to the MME. Referring to FIG. 5I, the suspend procedure of suspending the RRC connection may further include at least one of: step 552: in response to triggering the suspend procedure, sending, by the apparatus, a suspend indication to the MME, so that: the MME enters an idle state (e.g, an evolved packet system (EPS) connection management-idle (ECM-IDLE) state) and sends a modify bearer request message to the SGW, the SGW sends a modify bearer response message to the MME, and the MME sends a S1-AP: UE context suspend response message to the apparatus; and step 554: receiving, by the apparatus, the S1-AP: UE context suspend response message to suspend/terminate the RRC connection with the UE.

The present disclosure describes another embodiment for early data transmission for downlink data. After the SGW triggers the MT-EDT data sending and the SGW has sent all the downlink data packets to the eNodeB, the SGW sends an end marker to the eNodeB; and after the eNodeB receives the end marker, the eNodeB performs the release or termination of the RRC connection or the S1 connection.

Referring to FIG. 6, an exemplary embodiment for early data transmission for downlink data with an involvement of an end marker using an EPS network, including at least one of a UE 610, an eNodeB 620, an MME 630, an SGW 640, and a PGW 650. The exemplary embodiment is described as following.

In 661, the PGW receives downlink data for the UE.

In 662, the PGW forwards the downlink data to the SGW.

In 663, the SGW sends a Downlink Data Notification message to the MME. In this message, the SGW includes the mobile-terminated early data transmission (MT-EDT) indication to the MME.

In 664, the MME responds with the Downlink Data Notification ACK to the SGW.

In 665, if the UE is registered in the MME and considered reachable for paging, the MME sends a Paging message to the eNodeB belonging to the tracking area (s) in which the UE is registered. In the paging message, the eNodeB may include the SAE-temporary mobile subscriber identity (S-TMSI) and the MT-EDT indication.

In 666, the eNodeB receives paging messages from the MME, the eNodeB sends the paging message with the MT-EDT indication to the UE.

In 667, the UE receives the paging message.

In 668, the UE responds the paging message and triggers the Random Access Preamble procedure to the eNodeB.

In 669, the eNodeB responds with the Random Access Response procedure.

In 670, the UE triggers the radio resource control (RRC) Connection Resume procedure including information needed by the eNodeB to access the UE's stored access stratum (AS) context.

In 671, the eNodeB notifies the MME that the UE's RRC connection is resumed in the S1-application protocol (S1-AP) UE Context Resume Request message, which includes an RRC resume cause. The MME enters a connected state (e.g, an EPS connection management (ECM) -CONNECTED state) . The MME identifies that the UE returns at the eNodeB for which MME has stored data related to the S1-AP association, UE Context and bearer context including the Downlink tunnel endpoint identifier (s) (DL TEID (s) ) , necessary to resume the connection,

In 672, the MME sends the Modify Bearer Request message to the SGW. In this message, the MME includes the eNodeB downlink TEID and IP address to the SGW; The SGW responds the Modify Bearer Response message to the MME.

In 673, the MME acknowledges the connection resumption in S1-AP UE Context Resume Response message.

In 674, the SGW can send the buffered downlink data to the eNodeB. If the SGW has sent all the downlink data or sent a last packet of the downlink data, the SGW can send an end marker to the eNodeB either together with the downlink data or separately from the downlink data. In another implementation, the end marker may be sent by the PGW rather than the SGW. The end Marker may include a GPRS tunneling protocol-user plane (GTP-U) message with a defined message identity or a user data packet plus GTP-U header (G-PDU) with a defined GTP-U header.

In 675, the eNodeB uses the RRC connection release message to contain the downlink data to the UE.

In 676, after the eNodeB receives the end marker, the eNodeB triggers the suspend procedure. The eNodeB indicates to the MME that the UE’s RRC connection is to be suspended upon which the MME enters ECM-IDLE. Data related to the S1-AP association, UE Context and bearer context, necessary to resume the connection is kept in the eNodeB, the UE and the MME.

In 677, the MME sends a Modify Bearer Request message to the SGW that requests the release of all S1-U bearers for the UE. The SGW responds with the Modify Bearer Response message.

In 678, the MME sends an S1-AP: UE Context Suspend Response message to the eNodeB to successfully terminate the Connection Suspend procedure initiated by the eNodeB.

Referring to FIG. 7, a user equipment (UE) 410 may communicate with a 5G network 700. The UE may communicate with a new-generation radio access network (NG RAN) 720. The NG RAN 720 may communicate with an access and mobility management function (AMF) 730 via an interface N2. The AMF 730 may perform at least one of the following functions: registration management, connection management, reachability management, mobility management, access authentication, and access authorization. The AMF 730 may be an NAS security termination and may relay the session management (SM) NAS between the UE and the SMF, etc. The AMF 730 may also communicate with a session management function (SMF) 740 via an interface N11. The SMF 740 may perform at least one of the following functions: session management, session establishment, session modification and release, UE IP address allocation and management (including optional authorization) , session selection and control of UP function, downlink data notification, etc. The NG RAN 720 may also communicate with a user plane function (UPF) 750 via an interface N3. The UPF 750 may also communicate with the SMF 740 via an interface N4. The UPF may perform at least one of the following functions: nnchor point for intra-/inter-RAT mobility, packet routing &forwarding, traffic usage reporting, quality of service (QoS) handling for user plane, downlink packet buffering and downlink data notification triggering, etc.

Referring to FIG. 8A, the present disclosure describes a method 800 for early data transmission for downlink data. The method 800 may include at least one of: step 810: receiving, by an apparatus, a paging message; step 820: sending, by the apparatus, the paging message to a user equipment (UE) ; step 830: establishing, by the apparatus, a radio resource control (RRC) connection with the UE; step 840: receiving, by the apparatus, an end marker; and step 850: in response to receiving the end marker, triggering, by the apparatus, a suspend procedure of suspending the RRC connection with the UE.

In step 810, the method 800 may include receiving, by an apparatus, a paging message. The apparatus may include a memory storing instructions and a processor in communication with the memory. The paging message comprising a mobile terminated-early data transmission (MT-EDT) indication. In one implementation, the apparatus may include an NG RAN, and the method 800 may include receiving, by the apparatus, the paging message from an AMF.

Referring to FIG. 8B, in another implementation, before receiving, by the apparatus, the paging message, the method 800 may further include at least one of: step 801: in response to receiving downlink data, a user plane function (UPF) sends a downlink data notification to a session management function (SMF) , the downlink data notification comprising the MT-EDT indication; step 802: the SMF sends a downlink data notification acknowledgment (ACK) to the UPF; step 803: the SMF sends a communication transfer message to the AMF, the communication message comprising the MT-EDT indication; step 804: the AMF sends a communication transfer message response to the SMF; and step 805: the AMF sends the paging message to the apparatus.

In step 820, the method may include sending, by the apparatus, the paging message to a user equipment (UE) . In one implementation, after the NG RAN receives the paging message from the AMF, the NG RAN may send the paging message with the MT-EDT indication to the UE.

In step 830, the method may include establishing, by the apparatus, a radio resource control (RRC) connection with the UE. Referring to FIG. 8C, in one implementation, the step 830 may include at least one of: step 831: receiving, by the apparatus, a random access preamble from the UE; step 832: sending, by the apparatus, a random access response to the UE; and step 833: receiving, by the apparatus, a RRC connection resume request from the UE.

Referring to FIG. 8D, in another implementation, the step 830 may further include at least one of the following: step 834: in response to establishing the RRC connection with the UE, the apparatus send an UE context resume request to the AMF, so that the AMF enters a connected state; step 835: the AMF sends a context request to the SMF; step 836: the SMF sends a N4 session modification to the UPF; step 837: the SMF sends a context response to the AMF; and step 838: the AMF sends a UE context resume response to the apparatus. The context request may include an Nsmf_PDUSession_UpdateSMContext Request, which may include at least one of PDU Session ID, Cause, Operation type, User Location Information, Age of Location Information, N2 SM Information. The Operation Type may be set as “UP Resume” to indicate resume of user plane resources for the PDU Session. The context response may include an Nsmf_PDUSession_UpdateSMContext response.

In step 840, the method may include receiving, by the apparatus, an end marker. The step 840 may include receiving, by the apparatus, a portion or all of the downlink data from the UPF; and sending, by the apparatus, a RRC connection release message to the UE, the RRC connection release message including the portion or all of the downlink data.

In one implementation, an end marker may be initiated by the UPF, and the end marker is transmitted together with a last packet of the downlink data from the UPF to the apparatus (e.g., NG RAN) . For example, the end marker may be disposed at the end of the last packet of the downlink data. Referring to FIG. 8E, the step 840 may include at least one of: step 542-1: receiving, by the apparatus, a last packet of the downlink data together with the end marker from the UPF; and step 544-1: sending, by the apparatus, a RRC connection release message to the UE, the RRC connection release message comprising the last packet of the downlink data.

In another implementation, an end marker may be initiated by the UPF, and the end marker is transmitted separately from a last packet of the downlink data from the UPF to the apparatus (e.g., NG RAN) . For example, the UPF may send the last packet of the downlink data to the NG RAN, and then, the UPF may separately send the end marker to the NG RAN. Referring to FIG. 8F, the step 840 may include at least one of: step 842-2: receiving, by the apparatus, a last packet of the downlink data from the UPF; step 842-4: receiving separately, by the apparatus, the end marker from the UPF; and step 842-6: sending, by the apparatus, a RRC connection release message to the UE, the RRC connection release message comprising the last packet of the downlink data.

In step 850, the method 800 may include in response to receiving the end marker, triggering, by the apparatus, a suspend procedure of suspending the RRC connection with the UE. In response to triggering the suspend procedure, the method may further include sending, by the apparatus, a suspend indication to the AMF. Referring to FIG. 8G, the suspend procedure of suspending the RRC connection may further include at least one of: step 852: in response to triggering the suspend procedure, sending, by the apparatus, a N2 suspend request message to the AMF, so that: the AMF enters an idle state (e.g., 5G mobility management idle (5GMM-IDLE) state) with a suspend indicator and sends a context request to the SMF, the SMF sends a N4 session modification request to the UPF, the SMF sends a context response to the AMF, and the AMF sends a RRC suspend message to the apparatus; and step 854: receiving, by the apparatus, the RRC suspend message to suspend the RRC connection with the UE.

The present disclosure describes another embodiment for early data transmission for downlink data. After the UPF triggers the MT-EDT data sending and the UPF has sent all the downlink data packets to the NG RAN, the UPF sends an end marker to the NG RAN; and after the NG RAN receives the end marker, the NG RAN performs the release or termination of the RRC connection or the N2 connection.

Referring to FIG. 9, an exemplary embodiment for early data transmission for downlink data with an involvement of an end marker using a 5G network, including at least one of a UE 910, an NG RAN 920, an AMF 930, an SMF 940, and a UPF 950. The exemplary embodiment is described as following.

In 961, the UPF receives downlink data for the UE.

In 962, the UPF receives the downlink data and the UPF sends a Downlink Data Notification message to the SMF. The Downlink Data Notification message may include the UPF includes the EDT (early data transmission) indication to the SMF.

In 963, the SMF responds with the Downlink Data Notification ACK to the UPF.

In 964, the SMF sends to the AMF Namf_Communication_N1N2MessageTransfer, which may include at least one of SUPI, PDU Session ID, EDT indication.

In 965, the AMF sends to the SMF a Namf_Communication_N1N2MessageTransfer response message.

In 966, when the UE is registered in the AMF and considered reachable for paging, the AMF sends a Paging message to the NG-RAN belonging to the tracking area (s) in which the UE is registered. In the paging message, the NG-RAN will include the 5G-S-TMSI and the EDT indication.

In 967, the NG-RANs receive paging messages from the AMF, and the NG-RAN sends the paging message with the EDT indication to the UE.

In 968, the UE received the paging message.

In 969, the UE responds to the paging message and triggers the Random Access Preamble procedure to the NG-RAN.

In 970, the NG-RAN responds with the Random Access Response procedure.

In 971, the UE triggers the RRC Connection Resume procedure including information needed by the NG-RAN to access the UE’s stored AS context.

In 972, the NG-RAN notifies the AMF that the UE’s RRC connection is resumed in the N2-AP UE Context Resume Request message, which includes an RRC resume cause. The AMF enters a connected state (e.g, a 5GMM-CONNECTED state) . The AMF identifies that the UE returns at the NG-RAN for which AMF has stored data related to the N2-AP association, UE Context and Session context including the DL TEID (s) , necessary to resume the connection,

In 973, the AMF invokes Nsmf_PDUSession_UpdateSMContext Request, which may include at least one of PDU Session ID, Cause, Operation type, User Location Information, Age of Location Information, or N2 SM Information. The Operation Type may be set to “UP Resume” to indicate resume of user plane resources for the PDU Session.

In 974, the SMF sends to the UPF a N4 Session Modification Request, including that AN Tunnel Info to be resumed.

In 975, the SMF sends to the AMF an Nsmf_PDUSession_UpdateSMContext response.

In 976, the AMF acknowledges the connection resumption in N2-AP UE Context Resume Response message and/or sends a UE context resume response to the NG RAN.

In 977, the UPF sends the buffered downlink data to the NG-RAN. If the UPF has sent all the downlink data, the UPF may send an end marker to the NG-RAN either together with the last packet of the downlink data or separately from the last packet of the downlink data.

In 978, the NG-RAN uses the RRC connection release message to contain the downlink data to the UE.

In 979, After the NG-RAN receives the end marker, the NG-RAN triggers the suspend procedure. The NG-RAN sends the N2 Suspend Request message to the AMF. The AMF enters 5GMM-IDLE with Suspend indicator. Context information related to the NGAP UE association, UE Context and PDU session context, necessary to resume the connection is stored in the UE, NG-RAN node and in the AMF.

In 980, for each of the PDU Sessions in the N2 Suspend Request, the AMF invokes and sends an Nsmf_PDUSession_UpdateSMContext Request to the SMF. The Nsmf_PDUSession_UpdateSMContext Request may include at least one of PDU Session ID, Cause, or Operation type. The Operation Type may be set to “UP Suspend” to indicate suspend of user plane resources for the PDU Session.

In 981, the SMF sends to the UPF an N4 Session Modification Request, which includes AN Tunnel Info to be suspended.

In 982, the SMF sends an Nsmf_PDUSession_UpdateSMContext Response to the AMF.

In 983, after response for each PDU session, the AMF sends an N2 Suspend Response to NG-RAN to successfully terminate the Connection Suspend procedure initiated by the NG-RAN. In another implementation, the NG-RAN may send a RRC suspend message to suspend the RRC Connection with the UE including a UE Resume ID.

The present disclosure describes methods, apparatus, and computer-readable medium for wireless communication. The present disclosure addressed the issues with determining when is a good time to suspend/terminate a RRC connection with a UE. The methods, devices, and computer-readable medium described in the present disclosure may facilitate the performance of wireless communication. The methods, devices, and computer-readable medium described in the present disclosure may also reduce UE’s power consumption by suspend a RRC connection, thus improving efficiency and overall performance. The methods, devices, and computer-readable medium described in the present disclosure may improves the overall efficiency of the wireless communication systems.

Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present solution should be or are included in any single implementation thereof. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present solution. Thus, discussions of the features and advantages, and similar language, throughout the specification may, but do not necessarily, refer to the same embodiment.

Furthermore, the described features, advantages and characteristics of the present solution may be combined in any suitable manner in one or more embodiments. One of ordinary skill in the relevant art will recognize, in light of the description herein, that the present solution can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the present solution.

Claims

A method for wireless communication, comprising:

receiving, by an apparatus comprising a memory storing instructions and a processor in communication with the memory, a paging message, the paging message comprising a mobile terminated-early data transmission (MT-EDT) indication;

sending, by the apparatus, the paging message to a user equipment (UE) ;

establishing, by the apparatus, a radio resource control (RRC) connection with the UE;

receiving, by the apparatus, an end marker; and

in response to receiving the end marker, triggering, by the apparatus, a suspend procedure of suspending the RRC connection with the UE.
The method of claim 1, wherein the establishing, by the apparatus, the RRC connection with the UE comprising:

receiving, by the apparatus, a random access preamble from the UE;

sending, by the apparatus, a random access response to the UE; and

receiving, by the apparatus, a RRC connection resume request from the UE.
The method of any of claims 1-2, wherein:

the end marker comprises at least one of:

a general packet radio service (GPRS) tunneling protocol-user plane (GTP-U) message with a defined message identity, or

a user data packet with a defined GTP-U header.
The method of any of claims 1-3, wherein:

the apparatus comprises an evolved node B (eNodeB) ;

the receiving, by the apparatus, the paging message comprises:

receiving, by the apparatus, the paging message from a mobility management entity (MME) .
The method of claim 4, wherein:

in response to receiving downlink data, a packet data network gateway (PGW) sends the downlink data to a serving gateway (SGW) ;

the SGW sends a downlink data notification to the MME, the downlink data notification comprising the MT-EDT indication;

the MME sends a downlink data notification acknowledgment (ACK) to the SGW; and

the MME sends the paging message to the apparatus.
The method of claim 5, further comprising:

in response to triggering the suspend procedure, sending, by the apparatus, a suspend indication to the MME, so that:

the MME enters an idle state and sends a modify bearer request message to the SGW,

the SGW sends a modify bearer response message to the MME, and

the MME sends a context suspend response message to the apparatus; and

receiving, by the apparatus, the context suspend response message to suspend the RRC connection with the UE.
The method of any of claims 5-6, wherein:

in response to establishing the RRC connection with the UE, the apparatus send an UE context resume request to the MME, so that the MME enters a connected state;

the MME sends a modify bearer request message to the SGW, the modify bearer request message comprises a downlink tunnel endpoint identifier (TEID) and an internet protocol (IP) address of the apparatus; and

the SGW sends a modify bearer response message to the MME.
The method of any of claims 5-7, wherein the receiving, by the apparatus, the end marker comprises:

receiving, by the apparatus, a last packet of the downlink data together with the end marker from the SGW; and

sending, by the apparatus, a RRC connection release message to the UE, the RRC connection release message comprising the last packet of the downlink data.
The method of any of claims 5-7, wherein the receiving, by the apparatus, the end marker comprises:

receiving, by the apparatus, a last packet of the downlink data from the SGW;

receiving separately, by the apparatus, the end marker from the SGW; and

sending, by the apparatus, a RRC connection release message to the UE, the RRC connection release message comprising the last packet of the downlink data.
The method of any of claims 5-7, wherein the receiving, by the apparatus, the end marker comprises:

generating, by the PGW, the end marker in response to an end of the downlink data;

sending the end marker from the PGW to the SGW;

receiving, by the apparatus, a last packet of the downlink data together with the end marker from the SGW; and

sending, by the apparatus, a RRC connection release message to the UE, the RRC connection release message comprising the last packet of the downlink data.
The method of any of claims 5-7, wherein the receiving, by the apparatus, the end marker comprises:

generating, by the PGW, the end marker in response to an end of the downlink data;

sending the end marker from the PGW to the SGW;

receiving, by the apparatus, a last packet of the downlink data from the SGW;

receiving separately, by the apparatus, the end marker from the SGW; and

sending, by the apparatus, a RRC connection release message to the UE, the RRC connection release message comprising the last packet of the downlink data.
A method for wireless communication, comprising:

receiving, by an apparatus comprising a memory storing instructions and a processor in communication with the memory, a paging message, the paging message comprising a mobile terminated-early data transmission (MT-EDT) indication;

sending, by the apparatus, the paging message to a user equipment (UE) ;

establishing, by the apparatus, a radio resource control (RRC) connection with the UE;

receiving, by the apparatus, an end marker; and

in response to receiving the end marker, triggering , by the apparatus, a suspend procedure of suspending the RRC connection with the UE.
The method of claim 12, wherein the establishing, by the apparatus, the RRC connection with the UE comprising:

receiving, by the apparatus, a random access preamble from the UE;

sending, by the apparatus, a random access response to the UE; and

receiving, by the apparatus, a RRC connection resume request from the UE.
The method of any of claims 12-13, wherein:

the end marker comprises at least one of:

a general packet radio service (GPRS) tunneling protocol-user plane (GTP-U) message with a defined message identity, or

a user data packet with a defined GTP-U header.
The method of any of claims 12-14, wherein:

the apparatus comprises a new-generation radio access network (NG RAN) ;

the receiving, by the apparatus, the paging message comprises:

receiving, by the apparatus, the paging message from an access and mobility management function (AMF) .
The method of claim 15, wherein:

in response to receiving downlink data, a user plane function (UPF) sends a downlink data notification to a session management function (SMF) , the downlink data notification comprising the MT-EDT indication;

the SMF sends a downlink data notification acknowledgment (ACK) to the UPF;

the SMF sends a communication transfer message to the AMF, the communication message comprising the MT-EDT indication;

the AMF sends a communication transfer message response to the SMF; and

the AMF sends the paging message to the apparatus.
The method of claim 16, further comprising:

in response to triggering the suspend procedure, sending, by the apparatus, a N2 suspend request message to the AMF, so that:

the AMF enters an idle state with a suspend indicator and sends a context request to the SMF,

the SMF sends a N4 session modification request to the UPF,

the SMF sends a context response to the AMF, and

the AMF sends a RRC suspend message to the apparatus; and

receiving, by the apparatus, the RRC suspend message to suspend the RRC connection with the UE.
The method of any of claims 16-17, wherein:

in response to establishing the RRC connection with the UE, the apparatus send an UE context resume request to the AMF, so that the AMF enters a connected state;

the AMF sends a context request to the SMF;

the SMF sends a N4 session modification to the UPF;

the SMF sends a context response to the AMF; and

the AMF sends a UE context resume response to the apparatus.
The method of any of claims 16-18, wherein the receiving, by the apparatus, the end marker comprises:

receiving, by the apparatus, a last packet of the downlink data together with the end marker from the UPF; and

sending, by the apparatus, a RRC connection release message to the UE, the RRC connection release message comprising the last packet of the downlink data.
The method of any of claims 16-18, wherein the receiving, by the apparatus, the end marker comprises:

receiving, by the apparatus, a last packet of the downlink data from the UPF;

receiving separately, by the apparatus, the end marker from the UPF; and

sending, by the apparatus, a RRC connection release message to the UE, the RRC connection release message comprising the last packet of the downlink data.
A wireless communications apparatus comprising a processor and a memory, wherein the processor is configured to read code from the memory and implement a method recited in any of claims 1 to 20.
A computer program product comprising a computer-readable program medium code stored thereupon, the code, when executed by a processor, causing the processor to implement a method recited in any of claims 1 to 20.