Flexible enablement of early data transfer

Abstract

A method includes downlink control signaling (6520) between a network (100, 101) and a terminal (102), the downlink control signaling (6520) including a control message (6010) indicating activation or deactivation of early data transmission (6800) in a random access procedure (600) of the terminal (102). The method also includes selectively adopting early data transmission (6800) according to the control message (6010).

Description

Technical Field

[0001] Various examples of the present invention generally relate to facilitating early data transmission in a random access procedure. Various examples of the present invention specifically relate to activating or deactivating early data transmission according to corresponding control signaling. Background Art

[0002] In a wireless communication system, a terminal (sometimes also referred to as a mobile device or user equipment UE) and a base station (BS) typically use a data connection to transmit data. A data connection is established between the UE and the network using a random access (RA) procedure. This involves network access performed by the UE. Resources on the spectrum can then be allocated to the UE to transmit data. This is sometimes also referred to as resource scheduling. Data connections facilitate resource scheduling.

[0003] The trigger for performing the RA procedure may include uplink (UL) data being scheduled or queued for transmission and / or receiving a downlink paging indicating that downlink (DL) data is scheduled for transmission and / or scheduling of DL data transmission. Typically, the RA procedure includes multiple messages (e.g., four messages); RA message 1 in the UL direction, RA message 2 in the DL direction, RA message 3 in the UL direction, and RA message 4 in the DL direction. Details of such RA procedures in the 3GPP Long Term Evolution (LTE) framework are described in 3GPP Technical Specifications (TS) 36.211, 36.231, 36.321, and 36.331. The RA procedure may be used to transition the operation of the UE from an idle mode to a connected mode.

[0004] According to the reference implementation, the various processes described above, including the scheduling of network access resources, may not be energy-efficient and may require a large amount of time. Therefore, the waiting time until data transmission is increased. This may be particularly important for Internet of Things (IOT) devices that are to be optimized for energy-efficient operation.

[0005] To alleviate this problem, early data transfer (EDT) has been discussed for Rel-15 eMTC and NB-IoT. With EDT, the UE can reduce the amount of signaling for small data transmission by including the UL payload data in RA message 3. Alternatively or additionally, the network can send the DL payload data in RA message 4.

[0006] Payload data is usually defined at a higher layer (e.g., layer 7 of a transport protocol stack). Payload data is sometimes referred to as user data or application data.

[0007] At the time point when the RA message 3 is sent from the UE to the network or BS, there is no user plane transport bearer for application data establishment, that is, no data connection is established. Therefore, EDT is a method that includes a container of payload data even before configuring a data connection.

[0008] However, EDT faces certain limitations. For example, according to the reference implementation, the activation of EDT is static. Therefore, scenarios may be encountered where statically enabled or disabled EDT is not beneficial in terms of, for example, quality of service (such as latency, spectral efficiency, and / or load imposed on participating devices). Summary of the invention

[0009] Therefore, there is a need for advanced techniques for EDT. In particular, there is a need for techniques for EDT that overcome or mitigate at least some of the limitations and disadvantages discussed above.

[0010] A method includes downlink control signaling. The downlink control signaling is between a network node and a UE. The downlink control signaling includes a control message. The control message indicates activation or deactivation of EDT in a RA process of the UE. The method also includes selectively adopting EDT according to the control message.

[0011] The computer program product or computer program includes a program code. The program code can be executed by at least one processor. Executing the program code causes the at least one processor to perform a method. The method includes downlink control signaling. The downlink control signaling is between a network node and a UE. The downlink control signaling includes a control message. The control message indicates the activation or deactivation of EDT in the RA process of the UE. The method also includes selectively adopting EDT according to the control message.

[0012] A device includes a control circuit. The control circuit is configured to perform downlink control signaling. The downlink control signaling is between a network node and a UE. The downlink control signaling includes a control message. The control message indicates the activation or deactivation of EDT in the RA process of the UE. The control circuit is also configured to selectively adopt EDT according to the control message. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A BS, a UE, and a wireless link between the BS and the UE according to various examples are schematically illustrated.

[0014] Figure 2 The BS and the UE are schematically illustrated in more detail.

[0015] Figure 3 A cellular network according to various examples is schematically illustrated.

[0016] Figure 4The operating modes of the UE according to various examples are schematically illustrated.

[0017] Figure 5 The RA procedure of a UE including EDT according to various examples is schematically illustrated.

[0018] Figure 6 The RA procedure of a UE including EDT according to various examples is schematically illustrated.

[0019] Figure 7 DL control signaling including a control message indicating activation or deactivation of EDT in a RA procedure according to various examples is schematically illustrated.

[0020] Figure 8 A network controlled EDT according to various examples is schematically illustrated.

[0021] Fig. 9 is a flow chart of a method according to various examples. DETAILED DESCRIPTION

[0022] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood that the description of the following embodiments should not be considered restrictive. The scope of the present invention is not intended to be limited by the embodiments or drawings described below, which are considered to be illustrative only.

[0023] The accompanying drawings are considered to be schematic representations, and the elements shown in the drawings are not necessarily shown to scale. Moreover, the various elements are represented so that their functions and general purposes become apparent to those skilled in the art. Any connection or coupling between the functional blocks, devices, components or other physical or functional units shown in the drawings or described herein may also be achieved by indirect connection or coupling. The connection between components may also be established by wireless connection. The functional blocks may be implemented in hardware, firmware, software or a combination thereof.

[0024] The techniques described herein may facilitate sending and / or receiving (transmitting) data between a UE and a BS of a network. For example, DL data and / or UL data may be transmitted. For example, payload data associated with a service performed at the UE and / or the network may be transmitted. For example, payload data may be transmitted between a UE and a packet data network (PDN) to which a network providing access to the UE is connected.

[0025] The technology described herein can be used in conjunction with IOT devices. Specifically, the technology described herein can be used in conjunction with third generation partnership project (3GPP) machine type communication (MTC) devices. The technology described herein can be used in conjunction with 3GPP narrowband IOT (NB-IOT) devices.

[0026] In the following, techniques related to the RA process of a UE connected to a network are described. For example, the network may be a cellular network comprising a plurality of cells, wherein each cell is defined by one or more BSs. Example network architectures include 3GPP LTE (4G) or new radio (5G) architectures. For example, the 3GPP LTE and NR protocols adopt an RA process (4-step RA process) comprising four messages exchanged between the UE and the BS. However, the techniques described herein are not limited to a four-step random access process. Other initial access procedures are also applicable, including but not limited to UE-initiated access procedures with a greater or lesser number of signaling steps. The techniques are further not limited to 3GPP cellular networks. Other kinds and types of networks may be implemented, such as ad hoc networks or non-cellular networks. The techniques are applicable to networks using licensed and unlicensed spectrum.

[0027] According to an example, in the RA process, the UE sends a UL RA message. The UL RA message includes a RA preamble. The UL RA message including the RA preamble is also referred to as RA message 1.

[0028] The RA preamble used in this article can be a pattern or a signature. The value of the RA preamble can help distinguish between different UEs. The RA preamble can be selected from a set of candidate preambles, for example, 64 or 128 candidate preambles. Different candidate preambles can use orthogonal codes. For example, a Zaddoff-Chu sequence can be used to generate an RA preamble. The Zaddoff-Chu sequence can form a base sequence or a root sequence. Different cyclic shifts can then be applied to obtain a specific RA preamble. Different UEs can use different cyclic shifts. Code division duplexing is possible. The selection can occur randomly or non-randomly, for example, depending on whether a contention-based RA process or a non-contention-based RA process is adopted. For example, the document 3GPP TSGRAN WG1#86bis R1-1609119 discloses a technology associated with a RA preamble design for 3GPP NR, which can be used in conjunction with the determination of the RA preamble.

[0029] In an LTE environment, if a preamble index has not yet been assigned to a UE, the UE may use a contention-based RA procedure. This may occur as part of a process known as RRC connection establishment. In this example, the UE may wish to send an RRC message known as an RRC connection request to the BS, in which the UE requests a change from an idle state (RRC_IDLE) to a connected state (RRC_CONNECTED). Since no resources are allocated for sending the corresponding request message, the UE randomly selects a preamble sequence from a pool of candidate preamble sequences, which pool is provided, for example, by the network. The UE then sends the selected preamble in RA message 1. If two or more UEs transmit on the same resource blocks using the same preamble sequence, there is a risk of contention.

[0030] The BS sends a scheduling command to the UE, followed by a RA response including a UL grant as RA message 2. Using the UL grant, the UE sends an RRC Connection Request message (RA message 3). As part of this message, the UE uniquely identifies itself. There is still a risk of contention between the UEs that initiate the process, but if one of the transmissions is stronger than the others, the BS will be able to decode that transmission. The other transmissions will cause interference. The BS sends an RRC Connection Response message (RA message 4), which includes an acknowledgment and echoes the RRC message sent by the UE in RA message 3, so the RRC Connection Response message includes the identity of the successful UE. Therefore, the contention can be resolved and the data connection can be established.

[0031] As explained in more detail below with reference to the accompanying drawings, the transmission of the payload data may have been completed during the above-mentioned RA process. Therefore, it is not necessary to complete the establishment of a data connection (such as a user plane default bearer or a dedicated bearer) before transmitting the payload data. The transmission of the payload data during the RA process is called EDT.

[0032] For example, the UL payload data may be included in the RRC connection request message (RA message 3), for example, multiplexed on the same transmission time interval (TTI). Thus, the UL payload data may be transmitted from the UE to the BS during the RA procedure. Alternatively or additionally, the DL payload data may be transmitted in the RRC response message (RA message 4) during the RA procedure.

[0033] According to various examples, control signaling for activating or deactivating EDT is employed. This may facilitate network control of activation or deactivation of EDT. According to an example, the network may thus authorize one or more UEs to activate EDT; the network may thus authorize one or more other UEs to deactivate EDT.

[0034] According to various examples, control signaling may enable or disable the UE's request for EDT. This scenario is particularly useful in the case where, for example, the UE requests EDT for DL ​​payload data in a RA procedure before the UE implements EDT for the payload data in the RA procedure.

[0035] According to various examples described herein, different techniques for enabling or disabling EDT are available. Specifically, the information included in the corresponding control signaling may vary in various examples.

[0036] Various implementations of control signaling:

[0037] The first example implementation includes cell-specific control signaling for EDT on / off switching. With this control signaling, the network can batch control whether any UE should be allowed to use EDT. Therefore, when this signaling is in the off state, the controlled UE will not request EDT. The corresponding cell-specific control signaling can be included in the system information broadcast in the corresponding cell. The corresponding command can be valid for all UEs or for a certain type / category of UEs. The control signaling can indicate that the cell supports EDT for the UE. The control signaling can allow the UE to request EDT.

[0038] A second example implementation includes UE-specific control signaling for EDT on / off switching. This implementation is comparable to cell-specific control signaling to some extent, but the control signaling is implemented per UE or for a group of UEs. The control signaling can be implemented as RRC signaling, for example, at network registration or when the UE transitions from an active state to an inactive / suspended state or the like. One-to-one control signaling between a respective UE and a respective BS is possible.

[0039] Using control signaling, the network can indicate to the controlled UE that the UE will use EDT for any upcoming transmission. The corresponding control message can be time-limited, that is, the corresponding control message can include a timer value during which no connection attempt / RA process is allowed unless these attempts use EDT. This timeout duration for mandatory EDT helps to alleviate network congestion. In this way, the control signaling can be called congestion control signaling. The corresponding control signaling can be implemented using a connection release message or in an RRC reconfiguration message. Such a message usually disconnects or modifies a data connection previously established through an RA procedure. Thus, for example, before or after converting the UE to idle mode, the network can indicate that if the UE wishes to initiate a new data transmission within a given time period, the UE is only allowed to do so through EDT. On the other hand, access restrictions for establishing a data connection between the UE and the network can be indicated. This helps to moderately restrict UE access under high network load conditions because it limits the network resources required to enable the UE to maintain cell access capabilities.

[0040] The corresponding control message may indicate an EDT limit relative to a maximum amount of payload data to be transmitted or a maximum amount of EDT accesses per time unit. For example, the control message may indicate a threshold count and / or a threshold rate for the EDT. Thus, it may be ensured that a UE that would need to transmit more payload data than is possible to transmit in an EDT transmission does not attempt to make multiple accesses in succession, but is instead restricted to abandoning connection to the network or reducing the payload data size before connecting.

[0041] The radio link performance level / channel quality can be used to control the activation / deactivation of EDT. A corresponding rule set can be defined. This is based on the finding that certain network conditions can be more or less conducive to the use of EDT. For example, the rule set can be linked to certain radio link performance parameters or generally the channel quality. As another example, the rule set can define the activation or deactivation of EDT based on the amount of data to be sent. For example, in the presence of a small amount of UL payload data, EDT can be enabled; while for a large amount of payload data, EDT can be disabled. As yet another example, the use of a high level of coverage enhancement (CE) can affect whether the network activates or deactivates EDT. Specifically, a rule set can be used to link the activation or deactivation of EDT to a certain CE level, so that the target CE level acts as a trigger for whether ED can be adopted. The CE level defines the number of data packet repetitions.

[0042] In general, a set of features that achieve relatively large coverage is referred to as CE. It is envisaged that CE will be applied to MTC and NB-IOT (sometimes also referred to as NB-LTE). The key feature of CE is to achieve multiple transmission repetitions of coded data. Here, each repetition may include the same redundant version of the coded data. The repetition may be "blind", that is, it may not respond to a corresponding retransmission request, which may be defined relative to a hybrid acknowledgement repeat request protocol (HARQ protocol). Moreover, the repetition according to CE may be preemptive. An example is provided in Section 6.2.1.3 of 3GPP Technical Report (TR) 45.820 Version 13.0.0 (2015–08). By adopting CE, even in scenarios where communication conditions on the corresponding wireless link are poor, a better aggregate signal-to-noise ratio and signal-to-interference ratio can be obtained by using multiple transmissions than that obtained by using a single packet transmission, thereby increasing the probability of successful transmission. Therefore, even for the low transmission power envisioned for the MTC and MB-IOT domains, network coverage can be significantly enhanced. According to an example, using CE, multiple repetitions of the corresponding RA message (e.g., using EDT) are used to redundantly transmit the coded payload data. Therefore, according to various examples, the data of the same coded version can be redundantly transmitted multiple times. The count of the repetitions defines the CE level. Each of the multiple repetitions can include data encoded according to the same redundant version (e.g., redundant version 0 or redundant version 1, etc.). Then, multiple repetitions of the coded data can be combined. This combination can be implemented in an analog domain such as a baseband. The combination produces a combined signal. Then, the decoding of the coded data can be based on the combined signal. Therefore, by aggregating the received information across multiple repetitions, the possibility of successfully decoding the coded data is increased. This technology of CE can find specific applications in the framework of IOT technology, for example, according to 3GPP MTC or NB-IOT. Here, typically, the UE that transmits realizes a relatively low transmit power. Nevertheless, due to the multiple repetitions of the coded data, a sufficiently high possibility of successful reception and decoding of the coded data is provided. As a specific implementation of the above-mentioned rule set, the rule set associated with the CE level can determine that EDT can be used only when the number of repetitions is 1, which means that the concept of CE is not used.

[0043] By using the techniques described herein, efficient transmission of payload data between a UE and a network can be achieved. Specifically, the transmission of payload data can be customized for the specific situation experienced (e.g., in terms of channel quality, load at the network, spectrum occupancy, etc.). Thus, the overall performance can be optimized.

[0044] Figure 1A wireless communication network 100 that can benefit from the techniques disclosed herein is schematically illustrated. The network 100 may be a cellular network including a plurality of cells, each associated with one or more BSs. The network may be a 3GPP standardized network, such as 3G, 4G-LTE, or the upcoming 5G-NR. Other examples include point-to-point networks, such as networks specified by the Institute of Electrical and Electronics Engineers (IEEE), for example, 802.11x Wi-Fi protocols or Bluetooth protocols. Other examples include 3GPP NB-IOT or eMTC networks.

[0045] The network 100 includes a BS 101 and a UE 102. For example, the UE 102 may be selected from the group consisting of: a smart phone; a cellular phone; a table; a notebook; a computer; a smart TV; an MTC device, an IoT device; a sensor; an actuator, and the like.

[0046] MTC or IOT devices are usually devices with low to medium requirements for data traffic and with relaxed latency requirements. In addition, communications using MTC or IOT devices should achieve low complexity and low cost. Further, the energy consumption of MTC or IOT devices should be relatively low so that battery-powered devices can operate for a considerable period of time: the battery life should be long enough. For example, IOT devices can use NB-IOT.

[0047] A wireless link 111 is established between BS 101 and UE 102. Wireless link 111 includes a DL link from BS 101 to UE 102; and also includes a UL link from UE 102 to BS 101. Time division duplex (TDD), frequency division duplex (FDD), space division duplex (SDD), and / or code division duplex (CDD) may be used to mitigate interference between UL and DL. Likewise, TDD, FDD, SDD, and / or CDD may be used to mitigate interference between UL and DL in wireless link 111 ( Figure 1 This helps to achieve non-competition-based or competition-free communication. For this purpose, time-frequency radio resources (hereinafter referred to as resources) can be used.

[0048] Figure 2 BS 101 and UE 102 are schematically illustrated in more detail. Base station 101 includes a processor 1011 and an interface 1012. Interface 1012 may include one or more antennas. Interface 102 may be configured to communicate over wireless link 111. BS 101 also includes a memory 1015 (e.g., a non-volatile memory). The memory may store program codes that can be executed by processor 1011. Executing the program code may cause processor 1011 to perform techniques related to: participating in a RA process with UE 102; controlling the activation and deactivation of EDT; controlling signaling to activate / deactivate EDT, etc.

[0049] UE 102 includes a processor 1021 and an interface 1022. Interface 1022 may include one or more antennas. Interface 1022 may be configured to communicate over wireless link 111. UE 102 also includes a memory 1025 (e.g., a non-volatile memory). Memory 1025 may store program codes that can be executed by processor 1021. Executing the program code may cause processor 1021 to perform techniques related to: participating in a RA process with BS 101; enabling and disabling EDT, for example, according to DL control signaling, etc.

[0050] For example, UE 102 may be one of: a smart phone; a mobile phone; a laptop computer; a tablet computer; a smart TV; an IOT device; an MTC device, etc.

[0051] Figure 3 1 illustrates aspects of the architecture of the cellular network 100 according to some example implementations. Figure 3 The example cellular network 100 implements the 3GPP LTE architecture, sometimes referred to as the Evolved Packet System (EPS). However, this is for exemplary purposes only. Specifically, for illustrative purposes only, various scenarios will be explained in the context of a wireless link 111 between a UE 102 and a BS 102 operating according to a 3GPP LTE radio access technology (RAT). Similar techniques can be easily applied to various RATs specified by 3GPP, such as Global System for Mobile Communications (GSM), Wideband Code Division Multiple Access (WCDMA), General Packet Radio Service (GPRS), Enhanced GSM Evolution Data Rates (EDGE), Enhanced GPRS (EGPRS), Universal Mobile Telecommunications System (UMTS) and High Speed ​​Packet Access (HSPA) and the corresponding architectures of associated cellular networks. The network 100 can operate according to the 3GPP NR protocol. Another specific example is the 3GPP NB-IoT RAT. The 3GPP NB-IoT RAT can be based on the 3GPP LTE RAT, i.e., Evolved UMTS Terrestrial Radio Access (E-UTRA). In addition, NB-IoT RAT can be combined with EPS, such as Figure 3 As illustrated. Alternatively or additionally, the various examples disclosed herein may be readily implemented for 3GPP NB-IoT RAT. Similarly, for MTC, the techniques described herein may be employed. Other examples include other types of networks, such as Institute of Electrical and Electronics Engineers (IEEE) 802.11X wireless LAN, Bluetooth, or Zigbee.

[0052] UE 102 registers with network 100. Figure 3In the example of FIG. 1 , UE 102 is connected to network 100 via a wireless link 111 to BS 101 of cellular network 100. BS 101 and UE 102 implement Evolved UMTS Terrestrial Radio Access Technology (E-UTRAN). Figure 3 In NR, BS 101 is called g NodeB (gNB).

[0053] Communication over wireless link 111 may be in the UL direction and / or the DL direction. BS 101 is connected to a gateway node implemented by a serving gateway (SGW) 117. SGW 117 may route and forward payload data and may act as a mobility anchor point during handover of UE 102.

[0054] SGW 117 is connected to a gateway node implemented by a packet data network gateway (PGW) 118. For the packet data network (PDN; Figure 3 For data (not shown in FIG), the PGW 118 serves as an exit point and an entry point for the cellular network 110: for this purpose, the PGW 118 is connected to an access point (AP) node 121 of the packet data network. The access point node 121 is uniquely identified by an access point name (APN). The APN is used by the UE 102 to seek access to the PDN.

[0055] In the 3GPP NR scenario, the SGW 117 and PGW 118 functions may be implemented by a user plane function (UPF).

[0056] For the packetized payload data of UE 102, PGW 118 can be an endpoint of an end-to-end data connection 160. Data connection 160 can be used to transmit payload data of a specific application. Different applications / services can use different data connections 160, or can at least partially share a certain data connection. Data connection 160 can be implemented by one or more bearers for transmitting service-specific data. EPS bearers are characterized by a specific set of service quality parameters indicated by a QoS class identifier (QCI). The data connection can be at least partially defined on layer 2 or layer 3 of a transport protocol stack implemented by BS 101 and UE 102 for communicating on wireless link 111. For example, in conjunction with 3GPP LTE E-UTRAN, data connection 160 can be implemented on a radio resource control (RRC) layer. RA procedures can be used to establish data connection 160. When UE 102 is operated in connected mode, data connection 160 can be established; but when UE 102 is operated in disconnected mode, data connection 160 may not be available.

[0057] The control layer of the core network includes a mobility management entity (MME) 116. The MME 116 function can be implemented by an access and mobility management function (AMF) and a session management function (SMF) in the 3GPP NR framework.

[0058] The Home Subscriber Server (HSS) 115 includes a repository containing user-related and subscriber-related information such as authentication and subscription information. In 3GPP NR, such functions may be implemented by an Authentication Server Function (AUSF) and / or a Unified Data Management (UDM) function.

[0059] The Policy and Charging Rules Function (PCRF) implements policy control to promote specific QoS. The corresponding functions are implemented by the Policy Control Function (PCF) in the 3GPP NR framework.

[0060] The MME 116 handles mobility and security tasks such as paging and access credentials. The MME 116 also keeps track of the operating mode of the UE 102, for example, whether the UE 102 is operating in a connected mode or a disconnected mode. The MME 116 is the termination point for non-access stratum (NAS) connections (i.e., control connections implemented on layers above the RRC layer).

[0061] The MME 116 may control the paging functionality. Thus, there may be a registry maintained by the MME 116 that identifies whether a certain UE is pageable or non-pageable. This may depend on the specific operating mode of the UE, for example, whether the UE 102 is operating in a connected mode or a disconnected mode. The operating mode may in turn be associated with the presence or absence of the data connection 160. Figure 4 Aspects related to this mode of operation are illustrated.

[0062] Figure 4 1 illustrates aspects of different operating modes 301-303 in which the UE 102 may operate. Figure 4 In all modes illustrated in the state diagram of , UE 102 may be registered with network 100, i.e., EMM-REGISTERED in 3GPP LTE or MM-REGISTERED in 3GPP NR. Accordingly, corresponding entries may be maintained at MME 116.

[0063] In connected mode 301, a data connection 160 is established. For example, a default bearer and optionally one or more dedicated bearers may be established between the UE 102 and the network 100. The establishment of the data connection includes a RA procedure.

[0064] To reduce power consumption, a transition may then be made from the connected mode 301 to a connected mode 302 employing a discontinuous reception (DRX) cycle (connected mode DRX).

[0065] The DRX cycle consists of an on-duration and an off-duration ( Figure 4 102 is not shown). During the off duration, the interfaces of UE 102 are not suitable for receiving data; for example, the analog and / or digital front end may be at least partially powered down. The timing of the DRX cycle is synchronized between UE 102 and BS 101 so that BS 101 can align any DL transmission with the on duration of the connected mode DRX cycle. Even during the off duration, the data connection 160 remains established in mode 302. The data connection 160 is not released.

[0066] In order to further reduce power consumption, a transition may be made to one or more disconnection modes 303 (also referred to as idle modes 303 ), wherein the data connection 160 is released and not established.

[0067] Idle mode 303 is again associated with an idle mode DRX cycle of UE 102. However, during the on-duration of the DRX cycle in idle mode 303, the interface of UE 102 is only adapted to receive paging. This may help limit the frequency bandwidth that needs to be monitored by the UE during the on-duration of the DRX cycle in idle mode 303, for example. This may help further reduce power consumption if compared to connected mode 302, for example.

[0068] The transition from idle mode 303 to one of the connected modes 301, 302 may involve a RA procedure. Figure 5 The details of the RA process are illustrated in FIG.

[0069] Figure 5 Aspects regarding the RA process 600 according to various examples are schematically illustrated. Figure 5 is a signaling diagram of communication between UE 102 and BS 101.

[0070] In a cellular communication protocol (e.g., defined by 3GPP in the LTE or NR framework), a connection establishment procedure (e.g., Figure 5 The RA process 600 may include the transmission of multiple messages. Before initiating the RA process 600, the UE may periodically listen to information blocks broadcast by one or more BSs of the network. For example, the broadcasted information blocks may include information such as the cell identity of the broadcasting BS. The RA process 600 may then be used to initiate a connection establishment attempt from the UE 102, and the RA process 600 may include a non-contention based process or a contention based process. In general, the contention based process may be performed in Figure 5The four-step handshake protocol shown in .

[0071] At 6501, based on the broadcasted information, the UE 102 may send a randomly selected RA preamble 6001 to the BS in a corresponding RA message 1. The RA message 1 may indicate a temporary identity of the UE 102.

[0072] In response to sending the preamble, the UE 102 may receive a RA response (RAR) message 6002 (also referred to as RA message 2) at 6502, which includes, for example, a new temporary identity of the UE 102, timing adjustment information, and a scheduling grant for UL resources. The scheduling grant may be addressed to the RA Radio Network Temporary Identity (RA-RNTI) of the UE 102.

[0073] Using these UL resources, the UE may send an RRC connection request 6003 (also referred to as RA message 3) at 6503. For example, in the context of the 3GPP LTE protocol, the connection request may originate from the RRC layer of the transport protocol stack (i.e., layer 3 according to the Open Systems Interconnection (OSI) model). The RRC connection request 6003 may include a connection establishment cause.

[0074] In response to the RRC Connection Request 6003, the UE 102 may receive a Contention Resolution Message 6004 (also referred to as RA Message 4) at 6504 to ensure that the correct UE is addressed. This message may also be referred to as an RRC Connection Request Response Message 6004. This completes the establishment of the data connection 160.

[0075] If the connection attempt of UE 102 to network 100 is successful, data connection 160 may be established. Wireless communication of payload UL data and / or payload DL data along data connection 160 may then begin.

[0076] There are various conceivable triggering criteria for the RA procedure 600. Examples include the reception of a network paging message or the reception of a wake-up signal by the UE 102. Other examples include UL payload data scheduled or queued for transmission to the network 100.

[0077] exist Figure 5 In the scenario of , the RA process 600 is configured for EDT 6800 of UL payload data 6009; therefore, the RA process 600 includes EDT 6800. Figure 5 As shown, at 6503, UL payload data 6009 is carried in RA message 3 6003. Alternatively or additionally, EDT 6800 may also include carrying DL payload data in RA message 4 6004 ( Figure 5 not shown).

[0078] As a general rule, various options are available for piggybacking payload data into at least one of the control messages 6003, 6004 of the RA process 600. For example, the payload data may be included in the NAS information field of the respective control message 6003, 6004 (e.g., for payload data via a control plane scenario).

[0079] Figure 5 The scenario may depend on CE. Here, at least some of the messages 6001-6004 may be sent repeatedly according to a given CE level. Typical CE levels are in the range of 50 to 5000 repetitions. Specifically, the CE level may be applied to the EDT of the payload data. In the scenario described herein, the CE level adopted may vary according to various parameters. CE may help to adjust the balance between signaling overhead and reliable transmission.

[0080] Figure 6 Aspects regarding the RA process 600 according to various examples are schematically illustrated. Figure 6 is a signaling diagram of communication between UE 102 and BS 101.

[0081] Figure 6 The scenario generally corresponds to Figure 5 The scene. Figure 6 In the scenario of , EDT 6800 also includes UL request 6101 included in RA message 1 6001 at 6511. In addition, Figure 6 In the scenario of , the EDT 6800 also includes a DL ACK 6102 of the UL request 6101. At 6502, the DL ACK 6102 is included in the RA message 2 6002. The DL ACK 6102 may include a positive ACK indicator or a negative ACK indicator. For example, if the DL ACK 6102 includes a positive ACK indicator, then at 6513, the UL payload data 6009 is piggybacked to the RA message 3 6003. In the case where the DL ACK 6102 includes a negative ACK indicator, such transmission of the payload data 6009 may also be suppressed or aborted. With the help of the UL request 6101 and the DL ACK 6102, for each RA process 600, the transmission of the payload data may be enabled / disabled according to a specific analysis of the situation. Optionally, it is possible to use the UL request 6101 to implement a request for resources, thereby adjusting the scheduling of resources for the RA message 3 6003 in the case of the UL payload data 6009 and / or adjusting the scheduling of resources for the RA message 4 6004 in the case of the DL payload data. The general concept of such a request 6101 is described in 3GPP TSG RAN WG2 meeting #99, R2-1709194.

[0082] According to various examples, the activation and deactivation of EDT (ie, the transmission of payload data 6009 and / or the transmission of UL request 6101) may be controlled by the network. Figure 7 The corresponding technology is described.

[0083] Figure 7 Aspects regarding the selective activation and deactivation of the EDT are schematically illustrated. Figure 7 is a signaling diagram of communication between UE 102 and BS 101.

[0084] At 6520, DL control signaling of the DL control message 6010 is implemented. The BS 101 transmits the DL control message 6010, and the UE 102 receives the DL control message 6010. The DL control message 6010 indicates activation or deactivation of EDT in the RA procedure 600. Then, EDT may be selectively adopted according to the DL control signaling.

[0085] The DL control signaling at 6520 is not part of the RA process 600. As a general rule, various options are available for implementing the DL control signaling at 6520. In one example, for a cell of the network 100 associated with the BS 101, the DL control signaling may be specific to the cell. Thereby, coherent control of the EDT across various UEs residing in the respective cell may be achieved. In addition, the control signaling overhead may be limited. In one example scenario, the control message 6010 may be included in the broadcast of the system information block. In another example, for the UE 102, the DL control signaling at 6520 may be specific to the UE. Thereby, customized control of the EDT for the UE 102 may be achieved. Specifically, the EDT may be controlled differently for different UEs residing in the respective cell. This allows flexible traffic shaping. For example, the UE-specific DL control signaling at 6520 may include, for example, the transmission of a UE-specific control message 6010 in a one-to-one communication. The control message 6010 may be a Layer 3 RRC control message. Figure 8 The corresponding scenario is illustrated in FIG.

[0086] Figure 8 The diagram schematically illustrates aspects of the activity of the UE 102 changing over time. Specifically, Figure 8 UE activity over time is plotted.

[0087] Initially, at 6521, UE 102 operates in connected mode 301, i.e., a data connection 160 is established (see Figure 3 and Figure 4 ). Then, using the data connection 160, UL payload data 6009 and / or DL ​​payload data are sent and / or received (transmitted).

[0088] At the end of the operation of UE 102 in connected mode 301, DL control message 6010 is transmitted and specifically received by UE 102. Therefore, when UE 102 operates in connected mode 301, DL control message 6010 can be transmitted. For example, control message 6010 can be a UE-specific control message. For example, UE-specific control message can be transmitted on a physical control channel associated with data connection 160 (e.g., a physical DL control channel (PDCCH) in 3GPP NR or LTE scenarios). In general, UE-specific control message can be a layer 3 control message of a corresponding open system interconnection (OSI) transport protocol stack; such a layer 3 control message can be implemented by an RRC control message in a 3GPP NR or LTE scenario.

[0089] exist Figure 8 In the scenario of control message 6010 and the release of data connection 160 (ie, when switching from connected mode 301 to idle mode 303 (see Figure 4 )) is transmitted in a related manner. Typically, when reconfiguring the data connection 160, a control message 6010 may also be transmitted. The corresponding implementation in the 3GPP NR or LTE scenario includes RRC connection release and RRC connection reconfiguration messages.

[0090] Typically, the DL control message 6010 may be sent before any RA process of the EDT 6800 controlled by the DL control message 6010. Thus, the desired control of activation or deactivation of the EDT is achieved.

[0091] exist Figure 8 In the scenario of , at 6523 and 6524, the RA process 600 including the EDT 6800 is performed. The payload data 6009 is sent by the UE 102.

[0092] exist Figure 8 In the scenario of FIG. 6010 , the control of the activation or deactivation of the EDT 6800 is expected and implemented within a certain timeout duration 650. The timeout duration is associated with the time validity of the EDT control provided by the control message 6010. For example, the control message 6010 may deactivate the EDT within the timeout duration 650 (in Figure 8 For example, control message 6010 may enable EDT for a timeout duration 650 (in Figure 8 Typically, the timeout duration 650 may be preconfigured, or an indicator indicating the timeout duration may be included in the control message 6010.

[0093] It would be possible for the control message 6010 to trigger a mandatory EDT within the timeout duration 650. Thus, the establishment of the data connection 160 may be inhibited within the timeout duration 650. Furthermore, for any transmission of payload data 6009, the EDT 6800 will be relied upon. Thus, access restrictions for establishing the data connection 160 may be indicated by the control message 6010. Thus, the RA process 600 at 6523 and 6524 may not be implemented for the purpose of establishing the data connection 160, but for the purpose of implementing the EDT 6800. Thus, traffic shaping and soft access restrictions may be implemented, since a certain amount of data may be transmitted using the EDT.

[0094] As a general rule, in addition to such explicit activation or deactivation of EDT 6800, it is also possible that the control message 6010 includes one or more rule sets. Such rule sets may define the activation or deactivation of EDT 6800 in a parameterized manner. Thus, when activating or deactivating EDT, UE 102 may consider one or more parameters. Thus, the rule set may define a general framework or constraints for the activation or deactivation. Such an implementation using a rule set facilitates adjusting the activation or deactivation based on any time-varying parameters (e.g., channel quality, CE level, etc.).

[0095] For example, the control message 6010 may indicate a rule set for the activation or deactivation of EDT, which rule set depends on the channel quality. In this case, the rule set may specify a threshold channel quality; then, the instantaneous channel quality measured, for example, by the UE 102 based on received signal strength, etc., may be compared to the threshold channel quality; based on the comparison, EDT 6800 may be activated or deactivated. As should be appreciated, EDT may be activated or deactivated over time as the channel quality changes. This facilitates situation-aware traffic shaping.

[0096] In another example, the rule set may alternatively or additionally depend on a CE level for repeated data transmissions. For example, the rule set may specify a threshold CE level; then, the instantaneous CE level, for example, set by the UE 102 based on channel quality, may be compared to the threshold CE level; based on the comparison, EDT may be enabled or disabled. As will be appreciated, EDT may be enabled or disabled over time as the CE level changes. This facilitates situation-aware traffic shaping.

[0097] In yet another example, the rule set may alternatively or additionally depend on the amount of UL payload data. For example, if the amount of UL payload data queued for transmission is less than a first threshold and / or greater than a second threshold, EDT may be enabled or disabled. This facilitates situation-aware traffic shaping.

[0098] In various examples, the control message 6010 can indicate a threshold count and / or a threshold rate for the EDT. For example, the threshold count can specify a maximum number of EDT opportunities within the entire timeout duration 650. Thus, the amount of resources occupied by the UE 102 can be limited, but the UE 102 is still given some flexibility to send priority UL payload data 6009. As an alternative or additional solution to such a threshold count, the control message 6010 can also indicate a threshold rate for the EDT. Thus, the EDT opportunities per time unit can be limited. This also helps to limit the amount of resources occupied by the UE 102.

[0099] Fig. 9 is a flow chart of a method according to various examples. For example, according to Fig. 9 The method can be performed by the control circuits 1011 and 1015 of BS101. Fig. 9 The method can be executed by the control circuits 1021 and 1025 of the UE 102.

[0100] At block 5001, DL control signaling is implemented to convey a control message. Block 5001 may include sending a control message and / or receiving a control message. For example, control message 6010 (see Figure 7 and Figure 8 ) can be transmitted in box 5001.

[0101] The control message indicates the activation or deactivation of EDT. This may be the intended control of EDT. Therefore, for the subsequent RA process, EDT can be activated or deactivated.

[0102] The DL control signaling may be specific to a cell associated with the transmitting BS. Here, the DL control signaling may include the transmission of a broadcast information block. The information block may implement a control message. The information elements of the information block may implement a control message. In other scenarios, the DL control signaling may be specific to a UE. The DL control signaling may then be sent in a one-to-one connection between the BS and the UE. For example, layer 3 control signaling may be implemented.

[0103] The control message may convey different information. For example, a mandatory EDT may be triggered to supplement the process for establishing a user plane data connection (eg, data connection 160 (see Figure 3 )) access restrictions. In other examples, the control message may indicate explicit deactivation of EDT. In some scenarios, the control message may implicitly indicate the activation or deactivation of EDT. This can be achieved by using a rule set. The rule set may depend on one or more parameters. The UE can then check for specific values ​​of one or more parameters when EDT may become appropriate. Example parameters include channel quality, CE level, payload data size, etc.

[0104] In any case, in block 5002, EDT is employed or not employed depending on the control message.

[0105] Although the invention has been shown and described with respect to certain preferred embodiments, equivalents and modifications will occur to others skilled in the art upon the reading and understanding of the specification. The present invention includes all such equivalents and modifications, and is limited only by the scope of the appended claims.

[0106] For illustration purposes, various scenarios have been described above in which EDT is employed to transmit UL payload data. Likewise, it is possible to employ EDT to transmit DL payload data.

[0107] As a further note, while various scenarios have been described in the context of 3GPP LTE scenarios, similar techniques can be easily applied to other types of networks such as Multefire or 3GPP NR scenarios.

Claims

1. A method of enabling or disabling early data transmission (6800), the method comprising: Downlink control signaling (6520) between a network (100, 101) and a terminal (102), the downlink control signaling (6520) comprising a control message (6010) indicating activation or deactivation of early data transmission (6800) in a random access procedure (600) of the terminal (102), wherein the control message (6010) is a layer 3 control message transmitted when releasing or reconfiguring a user plane data connection (160) between the terminal (102) and the network (100, 101), and wherein the control message (6010) indicates a rule set for enabling or disabling the early data transmission (6800); and Based on the rule set for enabling or disabling the early data transmission (6800): selectively employing the early data transmission (6800).

2. The method according to claim 1, in, The layer 3 control message is an RRC control message.

3. The method according to claim 1, in, The control message (6010) triggers a mandatory early data transmission (6800) for at least the timeout duration (650).

4. The method according to claim 1, in, The control message (6010) indicates access restrictions for establishing a user plane data connection (160) between the terminal (102) and the network (100, 101).

5. The method according to claim 1, in, The set of rules depends on the channel quality.

6. The method according to claim 1, in, The set of rules depends on the coverage enhancement level of the repeated data transmission.

7. The method according to claim 1, in, The rule set depends on the amount of uplink payload data (6009).

8. The method according to claim 1, in, The control message (6010) indicates at least one of a threshold count and a threshold rate for the early data transmission (6800).

9. The method according to claim 1, in, The early data transmission (6800) comprises an uplink request (6101) for transmission of payload data (6009), Wherein, the early data transmission includes a downlink confirmation (6102) of the uplink request.

10. The method according to claim 1, in, For a cell of the network (100, 101), the downlink control signaling (6520) is cell-specific.

11. The method according to claim 1, in, For the terminal (102) or multiple terminals, the downlink control signaling (6520) is terminal-specific.

12. The method according to claim 1, in, The downlink control signaling (6520) includes the transmission of broadcast information blocks of cells of the network (100, 101).

13. The method according to claim 1, in, The downlink control signaling (6520) includes a one-to-one transmission of the control message.

14. The method according to claim 1, in, The control message (6010) indicates the enabling or disabling of the early data transmission (6800) within a timeout duration (650).

15. A device (101, 102) comprising a control circuit (1011, 1015, 1021, 1025), the device being configured to perform: Downlink control signaling (6520) between a network (100, 101) and a terminal (102), the downlink control signaling (6520) comprising a control message (6010) indicating activation or deactivation of early data transmission (6800) in a random access procedure (600) of the terminal (102), in, The control message (6010) is a layer 3 control message transmitted when releasing or reconfiguring a user plane data connection (160) between the terminal (102) and the network (100, 101), and wherein the control message (6010) indicates a rule set for enabling or disabling the early data transmission (6800); and Based on the rule set for enabling or disabling the early data transmission (6800): selectively employing the early data transmission (6800).

16. The device (101, 102) according to claim 15, in, The control circuit (1011, 1015, 1021, 1025) is configured to perform the method according to any one of claims 2 to 14.

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