Method and apparatus for performing semi-static scheduling activation triggered by a user equipment

Abstract

The present disclosure relates to a method and apparatus for performing user equipment-triggered semi-static scheduling activation. A user equipment (UE) receives an SPS resource configuration from an eNode B (eNB) and sends information related to semi-static scheduling (SPS) activation for a specific logical channel to the eNB. The information may include timing information for the specific logical channel, which indicates when the SPS resources for the specific logical channel should be activated. The specific logical channel may correspond to vehicle-to-everything (V2X) communication.

Description

[0001] This application is a divisional application of the patent application with the application number 201780003328.0 (PCT / KR2017 / 001081), the international filing date of which is February 1, 2017, and which entered the Chinese Patent Office on March 28, 2018, and the invention title is "Method and Apparatus for Performing User Equipment Triggered Semi-Static Scheduling Activation in a Wireless Communication System". Technical Field

[0002] The present invention relates to a wireless communication, and more particularly, to a method and apparatus for performing user equipment (UE) triggered semi-static scheduling (SPS) activation in a wireless communication system. Background Art

[0003] The 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is a technology enabling high-speed packet communication. Many solutions have been proposed for LTE goals including those aimed at reducing user and provider costs, improving service quality, and expanding and enhancing coverage and system capacity. 3GPP LTE requires reducing cost per bit, increasing service availability, flexible use of frequency bands, simple structure, open interfaces, and appropriate power consumption of terminals as more advanced requirements.

[0004] The pace of LTE network deployment is accelerating worldwide, leveraging the inherent advantages of LTE such as higher data rates, lower latency, and higher coverage to enable more and more advanced services and Internet applications. The widely deployed LTE-based networks provide an opportunity for the automotive industry to realize the concept of "connected cars". By providing vehicle access to the LTE network, vehicles can be connected to the Internet and other vehicles, enabling a wide range of existing or new services to be envisioned. Vehicle manufacturers and cellular network operators have shown strong interest in vehicle wireless communications for proximity safety services as well as commercial applications. LTE-based vehicle-to-everything (V2X) research urgently needs to start from market demands, and the market for vehicle-to-vehicle (V2V) communication is particularly time-sensitive. There have been many research projects and field tests on connected vehicles in some countries and regions such as the United States / Europe / Japan / Korea.

[0005] V2X includes vehicle-to-vehicle (V2V) covering LTE-based communication between vehicles, vehicle-to-pedestrian (V2P) covering LTE-based communication between a vehicle and a device carried by an individual (e.g., a handheld terminal carried by a pedestrian, cyclist, driver, or passenger), and vehicle-to-infrastructure / network (V2I) covering LTE-based communication between a vehicle and a roadside unit (RSU) / network. The RSU is a transportation infrastructure entity implemented in an eNode B (eNB) or a fixed UE (e.g., an entity that sends speed notifications).

[0006] In V2X communication, it is important to reduce latency so that latency-critical data, such as Decentralized Environmental Notification Message (DENM) or Cooperative Awareness Message (CAM), is transmitted in a timely manner. Summary of the Invention

[0007] Technical Problem

[0008] The present invention provides a method and apparatus for performing User Equipment (UE)-triggered semi-persistent scheduling (SPS) activation in a wireless communication system. The present invention also provides a method and apparatus for performing UE-triggered SPS reactivation and / or release.

[0009] Technical Solution

[0010] In one aspect, a method for performing semi-persistent scheduling (SPS) activation by a User Equipment (UE) in a wireless communication system is provided. The method includes: receiving an SPS resource configuration from an evolved Node B (eNB); and transmitting information related to SPS activation for a specific logical channel to the eNB.

[0011] In another aspect, a User Equipment (UE) in a wireless communication system is provided. The UE includes a memory, a transceiver, and a processor coupled to the memory and the transceiver, the processor controlling the transceiver to receive an SPS resource configuration from an evolved Node B (eNB), and controlling the transceiver to transmit information related to SPS activation for a specific logical channel to the eNB.

[0012] Advantageous Effects

[0013] The UE is capable of triggering SPS activation, reactivation, and / or release. Brief Description of the Drawings

[0014] Figure 1 Shows the LTE system architecture.

[0015] Figure 2 A block diagram showing the architecture of a typical E-UTRAN and a typical EPC.

[0016] Figure 3 A block diagram showing the user plane protocol stack of the LTE system.

[0017] Figure 4 A block diagram showing the control plane protocol stack of the LTE system.

[0018] Figure 5 Shows an example of a physical channel structure.

[0019] Figure 6 Shows an example of SPS configuration and SPS activation request according to an embodiment of the present invention.

[0020] Figure 7 A method for a UE to perform SPS activation according to an embodiment of the present invention is shown.

[0021] Figure 8 A wireless communication system implementing an embodiment of the present invention is shown. Detailed implementation manners

[0022] The techniques described below can be used in various wireless communication systems, such as Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single-Carrier Frequency Division Multiple Access (SC-FDMA), etc. CDMA can be implemented with radio technologies such as Universal Terrestrial Radio Access (UTRA) or CDMA-2000. TDMA can be implemented with radio technologies such as Global System for Mobile Communications (GSM) / General Packet Radio Service (GPRS) / Enhanced Data Rate for GSM Evolution (EDGE). OFDMA can be implemented with radio technologies such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, Evolved UTRA (E-UTRA), etc. IEEE 802.16m is an evolution of IEEE 802.16e and provides backward compatibility with IEEE 802.16-based systems. UTRA is part of Universal Mobile Telecommunications System (UMTS). The 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is part of Evolved UMTS (E-UMTS) using E-UTRA. 3GPP LTE uses OFDMA in the downlink and SC-FDMA in the uplink. Long Term Evolution-Advanced (LTE-A) is an evolution of 3GPP LTE.

[0023] For clarity, the following description will focus on LTE-A. However, the technical features of the present invention are not limited thereto.

[0024] Figure 1 An LTE system architecture is shown. A communication network is widely deployed to provide various communication services such as Voice over Internet Protocol (VoIP) through IMS and packet data.

[0025] Reference Figure 1 , the LTE system architecture includes one or more User Equipments (UEs; 10), an Evolved UMTS Terrestrial Radio Access Network (E-UTRAN), and an Evolved Packet Core (EPC). The UE 10 refers to a communication device carried by a user. The UE 10 can be fixed or mobile and can be referred to by other terms such as Mobile Station (MS), User Terminal (UT), Subscriber Station (SS), wireless device, etc.

[0026] The E-UTRAN includes one or more evolved Node-Bs (eNBs) 20, and multiple UEs can be located in a cell. The eNB 20 provides the endpoints of the control plane and the user plane to the UE 10. The eNB 20 is typically a fixed station that communicates with the UE 10 and can be referred to by other terms such as a base station (BS), an access point, etc. One eNB 20 can be deployed per cell.

[0027] Hereinafter, the downlink (DL) represents the communication from the eNB 20 to the UE 10, and the uplink (UL) represents the communication from the UE 10 to the eNB 20. In the DL, the transmitter can be part of the eNB 20, and the receiver can be part of the UE 10. In the UL, the transmitter can be part of the UE 10, and the receiver can be part of the eNB 20.

[0028] The EPC includes a Mobility Management Entity (MME) and a Serving Gateway (S-GW). The MME / S-GW 30 can be located at the edge of the network and connected to an external network. For clarity, the MME / S-GW 30 will be simply referred to as the "gateway" herein, but it should be understood that this entity includes both the MME and the S-GW. A Packet Data Network (PDN) Gateway (P-GW) can be connected to the external network.

[0029] The MME provides various functions, including: non-access stratum (NAS) signaling to the eNB 20, NAS signaling security, access stratum (AS) security control, core network (CN) inter-node signaling for mobility between 3GPP access networks, idle mode UE reachability (including control and execution of paging retransmission), tracking area list management (for UEs in idle and active modes), Packet Data Network (PDN) Gateway (P-GW) and S-GW selection, MME selection for handovers with MME change, Serving GPRS Support Node (SGSN) selection for handovers to 2G or 3G 3GPP access networks, roaming, authentication, bearer management functions including dedicated bearer establishment, support for Public Warning System (PWS) (including Earthquake and Tsunami Warning System (ETWS) and Commercial Mobile Alert System (CMAS)) message transmission. The S-GW host provides multiple functions, including: per-user packet filtering (e.g., via deep packet inspection), lawful interception, UE Internet Protocol (IP) address allocation, transport-level packet marking in the DL, UL and DL service-level charging, gating and rate enhancement, DL rate enhancement based on Access Point Name Aggregate Maximum Bit Rate (APN-AMBR).

[0030] Interfaces for sending user services or control services can be used. The UE 10 is connected to the eNB 20 via the Uu interface. The eNBs 20 are connected to each other via the X2 interface. Adjacent eNBs can have a mesh network structure with the X2 interface. Multiple nodes can be connected between the eNB 20 and the gateway 30 via the S1 interface.

[0031] Figure 2 Block diagram showing the architecture of a typical E-UTRAN and a typical EPC. Refer to Figure 2 , the eNB 20 can perform the following functions: selection of the gateway 30, routing towards the gateway 30 during radio resource control (RRC) activation, scheduling and transmission of paging messages, scheduling and transmission of broadcast channel (BCH) information, dynamic allocation of resources for the UE 10 in both the UL and DL, configuration and specification of eNB measurements, radio bearer control, radio access control (RAC), and connection mobility control in the LTE_ACTIVE state. In the EPC, and as noted above, the gateway 30 can perform the following functions: paging initiation, LTE_IDLE state management, encryption of the user plane, SAE bearer control, and encryption and integrity protection of NAS signaling.

[0032] Figure 3 Block diagram showing the user plane protocol stack of the LTE system. Figure 4 Block diagram showing the control plane protocol stack of the LTE system. Based on the lower three layers of the Open System Interconnection (OSI) model well-known in communication systems, the layers of the radio interface protocol between the UE and the E-UTRAN can be classified into the first layer (L1), the second layer (L2), and the third layer (L3).

[0033] The physical (PHY) layer belongs to L1. The PHY layer provides an information transfer service to higher layers through physical channels. The PHY layer is connected to the media access control (MAC) layer, which is a higher layer of the PHY layer, through transport channels. Physical channels are mapped to transport channels. Data between the MAC layer and the PHY layer is transmitted through transport channels. Data is transmitted between different PHY layers, i.e., between the PHY layer on the transmitting side and the PHY layer on the receiving side, through physical channels.

[0034] The MAC layer, Radio Link Control (RLC) layer, and Packet Data Convergence Protocol (PDCP) layer belong to L2. The MAC layer provides services to the RLC layer, which is a higher layer of the MAC layer, via logical channels. The MAC layer provides data transfer services on logical channels. The RLC layer supports reliable data transmission. Meanwhile, the functions of the RLC layer are implemented using functional blocks within the MAC layer. In such a case, the RLC layer may not exist. The PDCP layer provides the function of header compression to reduce unnecessary control information, enabling data transmitted using IP packets such as IPv4 or Ipv6 to be efficiently transmitted over a radio interface with a relatively small bandwidth.

[0035] The Radio Resource Control (RRC) layer belongs to L3. The RLC layer is located at the lowest part of L3 and is defined only in the control plane. The RRC layer controls logical channels, transport channels, and physical channels regarding the configuration, reconfiguration, and release of radio bearers (RBs). An RB represents the service of L2 that provides for data transfer between the UE and the E-UTRAN.

[0036] Reference Figure 3 , the RLC and MAC layers (terminated at the eNB on the network side) can perform functions such as scheduling, Automatic Repeat Request (ARQ), and Hybrid ARQ (HARQ). The PDCP layer (terminated at the eNB on the network side) can perform user plane functions such as header compression, integrity protection, and encryption.

[0037] Reference Figure 4 , the RLC and MAC layers (terminated at the eNB on the network side) can perform the same functions for the control plane. The RRC layer (terminated at the eNB on the network side) can perform functions such as broadcasting, paging, RRC connection management, RB control, mobility functions, and UE measurement reporting and control. The NAS control protocol (terminated at the MME of the gateway on the network side) can perform functions such as SAE bearer management, authentication, LTE_IDLE mobility handling, paging initiation in LTE_IDLE, and security control of signaling between the gateway and the UE.

[0038] Figure 5 Shows an example of the physical channel structure. The physical channel transmits signaling and data between the UE and the PHY layer of the eNB using radio resources. The physical channel consists of multiple subframes in the time domain and multiple subcarriers in the frequency domain. One subframe of 1 ms consists of multiple symbols in the time domain. A specific symbol of the subframe, such as the first symbol of the subframe, can be used for the Physical Downlink Control Channel (PDCCH). The PDCCH carries dynamically allocated resources such as Physical Resource Blocks (PRBs) and Modulation and Coding Schemes (MCS).

[0039] DL transport channels include: Broadcast Channel (BCH) for transmitting system information, Paging Channel (PCH) for paging UEs, Downlink Shared Channel (DL-SCH) for transmitting user services or control signals, and Multicast Channel (MCH) for multicast or broadcast service transmission. DL-SCH supports HARQ and dynamic link adaptation by changing modulation, coding, and transmission power, as well as dynamic and semi-static resource allocation. DL-SCH can also enable the use of broadcast and beamforming for the entire cell.

[0040] UL transport channels include Random Access Channel (RACH) commonly used for initial access to the cell, Uplink Shared Channel (UL-SCH) for transmitting user services or control signals, etc. UL-SCH supports HARQ and dynamic link adaptation by changing transmission power and potentially modulation and coding. UL-SCH can also enable the use of beamforming.

[0041] According to the type of information transmitted, logical channels are classified into control channels for transmitting control plane information and traffic channels for transmitting user plane information. That is, a set of logical channel types is defined for different data transmission services provided by the MAC layer.

[0042] Control channels are only used for the transmission of control plane information. Control channels provided by the MAC layer include: Broadcast Control Channel (BCCH), Paging Control Channel (PCCH), Common Control Channel (CCCH), Multicast Control Channel (MCCH), and Dedicated Control Channel (DCCH). BCCH is a downlink channel for broadcasting system control information. PCCH is a downlink channel for transmitting paging information and is used when the network does not know the location cell of the UE. CCCH is used by UEs without an RRC connection to the network. MCCH is a point-to-multipoint downlink channel for sending Multimedia Broadcast Multicast Service (MBMS) control information from the network to the UE. DCCH is a point-to-point two-way channel used by UEs with an RRC connection to send dedicated control information between the UE and the network.

[0043] Traffic channels are only used for the transmission of user plane information. Traffic channels provided by the MAC layer include Dedicated Traffic Channel (DTCH) and Multicast Traffic Channel (MTCH). DTCH is a point-to-point channel dedicated to a UE for transmitting user information and can exist in both the uplink and downlink. MTCH is a point-to-multipoint downlink channel for sending service data from the network to the UE.

[0044] The uplink connection between the logical channels and the transport channels includes: DCCH that can be mapped to UL-SCH, DTCH that can be mapped to UL-SCH, and CCCH that can be mapped to UL-SCH. The downlink connection between the logical channels and the transport channels includes: BCCH that can be mapped to BCH or DL-SCH, PCCH that can be mapped to PCH, DCCH that can be mapped to DL-SCH, DTCH that can be mapped to DL-SCH, MCCH that can be mapped to MCH, and MTCH that can be mapped to MCH.

[0045] The RRC state indicates whether the RRC layer of the UE is logically connected to the RRC layer of the E-UTRAN. The RRC state can be divided into two different states such as the RRC idle state (RRC_IDLE) and the RRC connected state (RRC_CONNECTED). In RRC_IDLE, the UE can receive the broadcast of system information and paging information. Meanwhile, the UE designates the discontinuous reception (DRX) configured by the NAS, and the UE has been assigned an identity (ID) that uniquely identifies the UE in the tracking area and can perform public land mobile network (PLMN) selection and cell reselection. In addition, in RRC_IDLE, no RRC context is stored in the eNB.

[0046] In RRC_CONNECTED, the UE has an E-UTRAN RRC connection and context in the E-UTRAN, making it possible to send data to the eNB and / or receive data from the eNB. In addition, the UE is able to report channel quality information and feedback information to the eNB. In RRC_CONNECTED, the E-UTRAN knows the cell to which the UE belongs. Therefore, the network can send data to the UE and / or receive data from the UE, the network can control the mobility of the UE (handover to the GSM EDGE radio access network (GERAN) using network-assisted cell change (NACC) and inter-radio access technology (RAT) cell change commands), and the network can perform cell measurements on neighboring cells.

[0047] In RRC_IDEL, the UE designates the paging DRX period. Specifically, the UE monitors the paging signal at specific paging occasions in each UE-specific paging DRX period. The paging occasion is the time interval during which the paging signal is sent. The UE has its own paging occasion. The paging message is sent in all cells belonging to the same tracking area. If the UE moves from one tracking area (TA) to another TA, the UE sends a tracking area update (TAU) message to the network to update its location.

[0048] Describe semi-static scheduling (SPS). The E-UTRAN is capable of allocating semi-static DL resources for the first HARQ transmission to the UE. The RRC defines the periodicity of the semi-static DL grant. The PDCCH indicates whether the DL grant is a semi-static grant, i.e., whether it can be implicitly reused in the following TTI according to the periodicity defined by the RRC.

[0049] When needed, the retransmission is signaled explicitly via the PDCCH. In a subframe where the UE has semi-static DL resources, if the UE cannot find its cell radio network temporary identity (C-RNTI) on the PDCCH, it is assumed that the DL transmission is based on the semi-static allocation that has been assigned to the UE in the TTI. Otherwise, in a subframe where the UE has semi-static DL resources, if the UE finds its C-RNTI on the PDCCH, the PDCCH allocation overrides the semi-static allocation for that TTI, and the UE does not decode the semi-static resources.

[0050] When carrier aggregation (CA) is configured, the semi-static DL resources can only be configured for the primary cell (PCell), and only the PDCCH allocation for the PCell can override the semi-static allocation. When dual connectivity (DC) is configured, the semi-static DL resources can only be configured for the PCell or the primary secondary cell (PSCell). Only the PDCCH allocation for the PCell can override the semi-static allocation for the PCell, and only the PDCCH allocation for the PSCell can override the semi-static allocation for the PSCell.

[0051] In addition, the E-UTRAN is capable of allocating semi-static UL resources for the first HARQ transmission and potential retransmissions to the UE. The RRC defines the periodicity of the semi-static UL grant. The PDCCH indicates whether the UL grant is a semi-static grant, i.e., whether it can be implicitly reused in the following TTI according to the periodicity defined by the RRC.

[0052] In a subframe where the UE has semi-static UL resources, if the UE cannot find its C-RNTI on the PDCCH, UL transmission based on the semi-static allocation that has been assigned to the UE can be performed. The network decodes the predefined PRBs according to the predefined MCS. Otherwise, in a subframe where the UE has semi-static UL resources, if the UE finds its C-RNTI on the PDCCH, the PDCCH allocation overrides the static allocation for that TTI, and the UE's transmission follows the PDCCH allocation instead of the semi-static allocation. The retransmission is implicitly allocated in the case where the UE uses the semi-static UL allocation, or explicitly allocated via the PDCCH in the case where the UE does not follow the semi-static allocation.

[0053] Similar to DL, semi-static UL resources can only be configured for the PCell, and only the PDCCH allocation for the PCell can cover the semi-static allocation. When DC is configured, semi-static UL resources can only be configured for the PCell or the PSCell. Only the PDCCH allocation for the PCell can cover the semi-static allocation for the PCell, and only the PDCCH allocation for the PSCell can cover the semi-static allocation for the PSCell.

[0054] When SPS is enabled via RRC, the following information is provided:

[0055] - SPS C-RNTI;

[0056] - If SPS is enabled for UL, the UL SPS interval semiPersistSchedIntervalUL and the number of empty transmissions before implicit release implicitReleaseAfter;

[0057] - Whether twoIntervalsConfig is enabled or disabled for UL, only for time division duplex (TDD);

[0058] - If SPS is enabled for DL, the DL SPS semiPersistSchedIntervalDL interval and the number of HARQ processes configured for SPSnumberOfConfSPS-Processes;

[0059] When SPS for UL or DL is disabled by RRC, the corresponding configured grant or configured assignment shall be discarded.

[0060] The above information can be carried in the SPS-Config information element (IE). The IE SPS-Config is used to specify the SPS configuration. Table 1 shows the SPS-Config IE.

[0061]

[0062]

[0063] As described above, if SPS is enabled for DL, the SPS-Config IE may include at least one of the SPS C-RNTI (semiPersistSchedC-RNTI), the UL SPS interval (semiPersistSchedIntervalUL), the number of empty transmissions before implicit release (implicitReleaseAfter), whether the DL SPS interval (semiPersistSchedIntervalDL) is enabled or disabled for UL (twoIntervalsConfig), and the number of HARQ processes configured for SPS (numberOfConfSPS-Processes).

[0064] The SPS-Config IE may be included in the RadioResourceConfigDedicated IE. The IERadioResourceConfigDedicated is used to set / modify / release RBs, to modify the MAC main configuration, to modify the SPS configuration, and to modify the dedicated physical configuration. The RadioResourceConfigDedicated IE may be included in one of the RRCConnectionReconfiguration message, the RRCConnectionReestablishment message, or the RRCConnectionSetup message. Table 2 shows the RadioResourceConfigDedicated IE.

[0065]

[0066]

[0067] Referring to Table 2, the RadioResourceConfigDedicated IE may include the SPS-Config IE. Except for handover or release of SPS for the master cell group (MCG), the E-UTRAN does not reconfigure the SPS-Config for the MCG when there is a configured DL assignment or a configured UL grant for the MCG. Except for SCG change or release of SPS for the SCG, the E-UTRAN does not reconfigure the SPS-Config for the SCG when there is a configured DL assignment or a configured UL grant for the SCG.

[0068] After configuring the SPS DL assignment, the MAC entity shall sequentially consider that the Nth assignment occurs in the following subframes, where:

[0069] -(10*SFN + subframe) = [(10*SFN开始时间 + subframe 开始时间 ) + N * semiPersistSchedIntervalDL] modulo 10240,

[0070] where SFN 开始时间 and subframe 开始时间 are the system frame number (SFN) and subframe respectively when the configured DL assignment is (re)initialized.

[0071] After configuring the SPS UL grant, the MAC entity will:

[0072] 1> If twoIntervalsConfig is enabled by the upper layer:

[0073] 2> Set Subframe_Offset according to Table 3 below.

[0074]

[0075] TDD UL / DL Configuration Position of Initial Semi-Static Grant Subframe Offset Value (ms) 0 N / A 0 1 Subframes 2 and 7 1 Subframes 3 and 8 -1 2 Subframe 2 5 Subframe 7 -5 3 Subframes 2 and 3 1 Subframe 4 -2 4 Subframe 2 1 Subframe 3 -1 5 N / A 0 6 N / A 0

[0076] 1> Others:

[0077] 2> Set Subframe_Offset to 0.

[0078] 1> Sequentially consider that the Nth grant occurs in the following subframe, where:

[0079] (10 * SFN + subframe) = [(10 * SFN 开始时间 + subframe 开始时间 ) + N * semiPersistSchedIntervalUL + Subframe_Offset * (N modulo 2)] modulo 10240,

[0080] where SFN 开始时间 and subframe 开始时间 are the SFN and subframe respectively when the configured uplink grant is (re)initialized.

[0081] Just after the MAC entity has provided implicitReleaseAfter consecutive new MAC PDUs each including zero MAC SDUs on the SPS resources through multiplexing and assembling entities, the MAC entity will clear the configured UL grant.

[0082] Describe vehicle-to-everything (V2X). V2X includes three types, which are vehicle-to-vehicle (V2V) communication, vehicle-to-infrastructure (V2I) communication, and vehicle-to-pedestrian (V2P) communication. These three types of V2X can use "cooperative awareness" to provide more intelligent services for end users. This means that traffic entities, such as vehicles, roadside infrastructure, and pedestrians, can collect knowledge of their local environment (e.g., information received from other vehicles or nearby sensor devices) to process and share this knowledge in order to provide more intelligent services, such as cooperative collision warning or autonomous driving.

[0083] A V2X service is a communication service that involves transmitting or receiving UEs using V2V applications via 3GPP. Based on the other party involved in the communication, it can be further divided into V2V services, V2I services, and V2P services. A V2V service is a V2X service in which both parties to the communication are UEs using V2V applications. A V2I service is a V2X service in which one party is a UE and the other party is a roadside unit (RSU), both using V2I applications. An RSU is an entity that supports the use of V2I services and can send V2I services to UEs and receive V2I services from UEs using V2I applications. The RSU is implemented in an eNB or a fixed UE. A V2P service is a V2X service in which both parties to the communication are UEs using V2P applications. A V2N service is a V2X service in which one party is a UE and the other party is a service entity, both using V2N applications and communicating with each other via an LTE network entity.

[0084] For V2V, when the permission, authorization, and proximity criteria are met, the E-UTRAN allows such UEs in proximity to each other to exchange V2V-related information using E-UTRA(N). The proximity criteria can be configured by a mobile network operator (MNO). However, UEs supporting V2V services can exchange such information whether they are served by an E-UTRAN supporting V2X services or not. UEs supporting V2V applications send application layer information (e.g., regarding their location, dynamics, and attributes as part of the V2V service). The V2V payload must be flexible to accommodate different information contents and can send information periodically according to the configuration provided by the MNO. V2V is mainly based on broadcasting. V2V includes directly exchanging V2V-related application information between different UEs and / or, due to the limited direct communication range of V2V, exchanging V2V-related application information between different UEs via infrastructure supporting V2X services, such as RSUs, application servers, etc.

[0085] For V2I, the UE supporting V2I applications sends application layer information to the RSU. The RSU sends the application layer information to a group of UEs or a single UE supporting V2I applications. V2N is also introduced, where one party is the UE and the other party is the service entity, and both support V2N applications and communicate with each other via the LTE network.

[0086] For V2P, when the permission, authorization, and proximity criteria are met, the E-UTRAN allows such UEs in proximity to each other to use the E-UTRAN to exchange V2P-related information. The proximity criteria can be configured by the MNO. However, even when not served by the E-UTRAN supporting V2X services, UEs supporting V2P services can still exchange such information. UEs supporting V2P applications send application layer information. Such information can be broadcast by vehicles with UEs supporting V2X services (e.g., warning pedestrians), and / or by pedestrians with UEs supporting V2X services (e.g., warning vehicles). V2P includes directly exchanging V2P-related application information between different UEs (one for the vehicle and the other for the pedestrian), and / or, due to the limited direct communication range of V2P, exchanging V2P-related application information between different UEs via infrastructure supporting V2X services, such as RSUs, application servers, etc.

[0087] According to traditional techniques, if the interval between the generation of user data and the configured SPS resources is large, UL transmission using SPS may cause some delays. Therefore, if SPS is used for delay-sensitive services such as V2X communication, the SPS scheduling interval should be small enough to support the delay requirements. However, a smaller SPS scheduling interval may result in more overhead because the UE may not be able to fully utilize the configured SPS resources. Therefore, the interval between user data generation and the configured SPS resources should be small, while the SPS scheduling interval should be appropriate to meet the delay requirements. Currently, there is no mechanism to support this functionality.

[0088] Therefore, a method for performing UE-triggered SPS activation, reactivation, and / or release according to the present invention is proposed. According to an embodiment of the present invention, a UE may receive SPS configurations for one or more specific logical channels. The UE may receive SPS configurations for specific logical channels via system information, an RRC connection establishment message, an RRC connection reestablishment message, or an RRC connection release message. When data becomes available for a specific logical channel, the UE may request SPS activation from the eNB and then perform UL transmission by using the configured SPS resources according to the SPS activation command received from the eNB. The UE may send an SPS activation request to the eNB on a physical uplink control channel (PUCCH), a MAC control element (CE), or an RRC message. That is, the UE may send an SPS activation request to the eNB by using the control resources used to request SPS activation. The control resources may be PUCCH resources, random access resources, or new UL control channel resources. In addition, for example, during RRC connection (re)establishment, during handover, after handover completion, or in RRC_CONNECTED, the UE may send an SPS activation request to the eNB.

[0089] Since the UE actively requests SPS activation when there is UL data to be transmitted, the interval between the generation of UL data and the configured SPS resources can be reduced.

[0090] In another embodiment of the present invention, the UE may receive SPS configurations for a specific PDN or for a specific service / application such as V2X communication. The UE may receive SPS for a specific PDN or for a specific service / application via system information, an RRC connection establishment message, an RRC connection reestablishment message, or an RRC connection release message. When data becomes available for a specific PDN or a specific service / application, when in the RRC_IDLE state or the RRC suspended state, the NAS layer of the UE may trigger RRC connection (re)establishment with the establishment cause set to periodic / SPS resource request. The UE may request SPS activation from the eNB in an RRC connection (re)establishment request message and then perform UL transmission by using the configured SPS resources according to the SPS activation command received from the eNB.

[0091] Figure 6 An example of SPS configuration and SPS activation request according to an embodiment of the present invention is shown. Figure 6Illustrate how an eNB / UE configures and activates SPS resources according to an embodiment of the present invention. In this embodiment, the UE can be in any RRC state, that is, RRC_CONNECTED, RRC_IDLE, or RRC suspended state. In this embodiment, the SPS resources can be dedicated to V2X communication or V2X-related channels. For example, the SPS resources can be used only for sending V2X messages, such that the SPS resources can be licensed only via one or more specific channels, for example, configured to carry data via a logical channel for sending V2X messages.

[0092] 1. Step 1

[0093] The eNB provides the UE with an SPS configuration (SPS-Config) via RRC signaling. The SPS-Config can include at least one of the following information.

[0094] - Time / frequency information of the SPS resources

[0095] - Interval of the SPS resources, that is, the SPS scheduling interval

[0096] - SPS C-RNTI (which can be dedicated to one or more specific logical channels, such as for V2X communication)

[0097] - Validity duration (SPSValidDuration), where the SPS-Config is valid, for example, in units of subframes, radio frames, milliseconds, or seconds.

[0098] - List of at least one cell (SPSCellList) where the SPS-Config is valid.

[0099] – Logical channel identifier experiencing the SPS-Config, that is, a specific logical channel. In other words, UL data from only the logical channel indicated by the logical channel identifier can be sent by using the SPS resources. UL data from other logical channels cannot be sent by using the SPS resources.

[0100] The RRC signaling can be system information, RRC connection establishment message, or RRC connection reconfiguration message or RRC connection release message. If the UE is in RRC_IDLE, the UE can receive the SPS-Config via system information. Alternatively, if the UE is in RRC_CONNECTED, the UE can receive it via an RRC connection establishment message, RRC connection reconfiguration message, or RRC connection release message. When the UE moves to RRC_IDLE, the UE can maintain the SPS-Config. Therefore, the SPS-Config can be stored in the UE in RRC_IDLE.

[0101] When receiving SPS-Config via RRC signaling, the UE may (re)configure the SPS resources, which include the frequency information of the SPS resources, the PUCCH for SPS scheduling information, the SPS C-RNTI, the SPS scheduling interval, and the SPSCellList. However, the UE may not be able to determine the time information of the SPS resources including the SPS time offset until the SPS is activated.

[0102] 2. Step 2

[0103] When UL data becomes available for a specific logical channel, a specific PDN, or a specific service / application, the UE triggers a scheduling request (SR) to activate the SPS. The SR can be used for a specific logical channel, for a specific PDN, or for a specific service / application. For example, the SR can be specific to V2X communication, or specific to this SPS operation.

[0104] The UE can send the SR via the PUCCH. The SR can be used to request SPS activation from the eNB. The SR on the PUCCH can also be used to notify the eNB about the amount of UL data available for transmission on a specific logical channel. Subsequently, the UE can send a UL-SCH including a buffer status report (BSR) MAC CE that can be specific to a specific logical channel, a specific logical channel group, specific to V2X communication, or specific to this SPS operation. The UE can also indicate the SPS timing to the eNB together with the BSR MAC CE.

[0105] Alternatively, the UE can send the SR via random access. In this case, a random access preamble (i.e., Msg 1 in random access) or a scheduled transmission on the UL-SCH (i.e., Msg 3 in random access) can be used to request SPS activation from the eNB. Msg 1 or Msg 3 can also notify the eNB about the amount of UL data available for transmission on a specific logical channel. Msg3 can include a MAC CE such as a BSR MAC CE to notify the eNB about the amount of UL data available for transmission on a specific logical channel. The MAC CE can be used to activate the SPS. The MAC CE can be specific to a specific logical channel, a specific logical channel group, specific to V2X communication, or specific to this SPS operation. The UE can also indicate the SPS timing to the eNB together with the MAC CE.

[0106] The SPS timing is used to indicate to the eNB when the SPS should be activated. The SPS timing can directly indicate the SFN number and the subframe number, both corresponding to when the SPS should be activated. Alternatively, the SPS timing can indicate the time of the delay before sending the SPS timing. For example, the time of the delay before sending the SPS timing can be the time interval between the SR trigger timing and the MAC CE transmission timing.

[0107] The operation of step 2 will be described in detail according to the RRC state. The operation of step 2 can be applied to any RRC state.

[0108] (1) When the UE is in RRC_IDLE

[0109] When UL data becomes available for a specific logical channel, a specific PDN, or a specific service / application (e.g., V2X communication), and when SPS-Config is available for the serving cell (since the UE receives SPS-Config via system information or RRC connection release message), the UE triggers connection establishment and sends a message to the eNB to activate SPS resources. The message can include at least one of the following. The message can correspond to an RRC connection request message, an RRC connection resume request message, or an RRC connection re-establishment request message.

[0110] - UE ID, such as System Architecture Evolution (SAE) Temporary Mobile Subscriber Identity (S-TMSI) or C-RNTI; or

[0111] - Cell ID corresponding to the cell where C-RNTI is allocated, such as Physical Cell ID; or

[0112] - SPS activation request and / or V2X indication, e.g., in the establishment cause; or

[0113] - Resume ID (if the UE has suspended data Radio Bearers (DRBs))

[0114] – SPS timing

[0115] (2) When the UE is in RRC_CONNECTED: The UE in RRC_CONNECTED can receive a handover command (e.g., an RRC connection reconfiguration message with mobility control information), or the UE can select another cell without a handover command, regardless of the RRC state.

[0116] When UL data becomes available for a specific logical channel, a specific PDN, or a specific service / application (e.g., V2X communication), and when SPS-Config is available for the serving cell (since the UE receives SPS-Config via system information or handover command), if the UE is not in the target cell, the UE performs UL transmission towards the source cell by using SPS resources. For example, before the UE synchronizes with the DL of the target cell or before the UE performs random access towards the target cell, the UE can perform UL transmission towards the source cell by using SPS resources.

[0117] When UL data becomes available for a specific logical channel, a specific PDN, or a specific service / application (e.g., V2X communication), and when SPS-Config is available for the serving cell (since the UE receives SPS-Config via system information or a handover command), if the UE is in the target cell, the UE sends a handover complete message to the target cell to activate the SPS resources. For example, after the UE is synchronized to the target cell or after the UE performs random access towards the target cell, the UE may send a handover complete message to the target cell to activate the SPS resources. The target cell may send a handover command to the source cell. The handover command may include the UE's C-RNTI and the UE's SPS C-RNTI, both of which are used at the target cell. The handover complete message may include at least one of the following. The handover complete message may correspond to an RRC connection reconfiguration complete message, an RRC connection request message, an RRC connection resume request message, or an RRC connection re-establishment request message.

[0118] - UE ID, such as C-RNTI (assigned by the source cell or the target cell), e.g., in the C-RNTI MAC CE; or

[0119] - Cell ID corresponding to the cell that assigned the C-RNTI, such as, Physical Cell ID; or

[0120] - SPS activation request and / or V2X indication, e.g., in the establishment cause; or

[0121] - Resume ID (if the UE has suspended the DRB)

[0122] – SPS timing

[0123] Meanwhile, when the UE wants to request SPS reactivation, e.g., when the SPS timing needs to be adjusted, the above operations in step 2 can be performed. Therefore, the UE can also send an SPS activation request for SPS reactivation. Once an SPS activation command (i.e., an SPS reactivation command) is received, the UE can replace the old SPS resources with new SPS resources. For example, the time offset can be replaced by the SPS reactivation command.

[0124] 3. Step 3

[0125] Once receiving an SPS activation request from a UE, the eNB sends an SPS activation command to the UE to activate SPS. The SPS activation request can be received via a scheduling request on the PUCCH or an RRC message such as an RRC connection request message, an RRC connection resume request message, an RRC connection reconfiguration complete message, an RRC connection reconstruction request message, or a handover complete message. The SPS activation command can correspond to a PDCCH, a MAC CE addressed to the UE's C-RNTI or SPS C-RNTI, or an RRC message such as an RRC connection setup message, an RRC connection reconstruction message, etc. The SPS activation command can also indicate when to activate SPS for the UE. For example, the SPS activation command can indicate an SPS time offset, which corresponds to the time interval between the transmission of the SPS activation command and the first SPS transmission.

[0126] The SPS activation command on the PDCCH addressed by the SPS C-RNTI can grant UL resources to the UE. The UL resources can be allocated before the first SPS transmission occurs, and the UL resources can be independent of the SPS resources. The UL resources can be used for data that can be transmitted on a specific logical channel. The UL resources can correspond to a single UL transmission including subsequent HARQ retransmissions.

[0127] 4. Step 4

[0128] Once receiving the SPS activation command from the eNB, the UE activates SPS transmission by using SPS-Config (configuration and). If the SPS activation command explicitly indicates when to activate SPS, i.e., the SPS time offset, the UE can activate SPS transmission according to the explicit SPS time offset. Otherwise, the SPS time offset can be determined as the Nth subframe starting from the subframe in which the SPS activation command is received. The value of N can be signaled by an RRC message or pre-fixed.

[0129] The UE can continue to perform UL transmission by using the SPS resources configured by SPS-Config. As long as the UE considers the SPS-Config valid, the UE can use the SPS resources configured by SPS-Config. To determine whether the SPS-Config is valid, the UE can use the SPSValidDuration and / or SPSCellList included in the SPS-Config.

[0130] A specific logical channel can correspond to a DRB or a signaling radio bearer (DRB). The UE can suspend the DRB for a specific logical channel and then resume the DRB when SPS is activated, i.e., when the SPS activation command is received.

[0131] 5. Step 5

[0132] The UE may request SPS release (or deactivation) by using one of SR (on PUCCH or random access), L1 UL control information, MAC CE, or RRC message. Once receiving the SPS release request (or disable request), the eNB may send an SPS release command (or disable command) to the UE. The SPS release command (or disable command) may correspond to a PDCCH addressed to the C-RNTI or SPSC-RNTI of the UE, a MAC CE, or an RRC message such as an RRC connection establishment message, an RRC connection reestablishment message. Once receiving the SPS release command (or disable command), the UE may release the configured SPS resources and stop using the configured SPS resources.

[0133] Figure 7 Fig. shows a method for SPS activation performed by a UE according to an embodiment of the present invention. The above present invention may be applied to this embodiment.

[0134] In step S100, the UE receives an SPS resource configuration from the eNB. The SPS resource configuration may be used for one of a specific logical channel, a specific PDN, a specific application, or a specific service. The specific logical channel, the specific PDN, the specific application, or the specific service corresponds to V2X communication. The SPS resource configuration includes a logical channel identifier indicating the specific logical channel experiencing the SPS resource configuration.

[0135] In step S110, the UE sends information about SPS activation for the specific logical channel to the eNB. The information may include a request for SPS activation, i.e., an SPS activation request. The information may be sent via SR on one of PUCCH, MAC CE, or RRC message. The information may include timing information for the specific logical channel. The timing information may indicate when the SPS resources for the specific logical channel should be activated. The timing information may include at least one of an SFN or a subframe number.

[0136] The UE may further receive an SPS activation command from the eNB. The SPS activation command may include an SPS time offset indicating when the SPS resources are activated. The SPS activation command on the PDCCH addressed by the SPS C-RNTI may grant UL resources. Once receiving the SPS activation command, the UE may also perform UL transmission to the eNB by using the SPS resources configured with the SPS resource configuration. In addition, the NAS layer of the UE may trigger connection establishment

[0137] Figure 8 Fig. shows a wireless communication system implementing an embodiment of the present invention.

[0138] The eNB 800 includes a processor 810, a memory 820, and a transceiver 830. The processor 810 may be configured to implement the functions, processes, and / or methods proposed in this specification. Layers of the radio interface protocol may be implemented in the processor 810. The memory 820 is operably coupled to the processor 810 and stores various information for operating the processor 810. The transceiver 830 is operably coupled to the processor 810 and transmits and / or receives radio signals.

[0139] The UE 900 includes a processor 910, a memory 920, and a transceiver 930. The processor 910 may be configured to implement the functions, processes, and / or methods proposed and described in this specification. Layers of the radio interface protocol may be implemented in the processor 910. The memory 920 is operably coupled to the processor 910 and stores various information for operating the processor 910. The transceiver 930 is operably coupled to the processor 910 and transmits and / or receives radio signals.

[0140] The processors 810, 910 may include an application specific integrated circuit (ASIC), other chip sets, logic circuits, and / or data processing devices. The memories 820, 920 may include a read only memory (ROM), a random access memory (RAM), a flash memory, a memory card, a storage medium, and / or other storage devices. The transceivers 830, 930 may include baseband circuits to process radio frequency signals. When an embodiment is implemented in software, the techniques described herein may be implemented by modules (e.g., procedures, functions, etc.) that execute the functions described herein. The modules may be stored in the memories 820, 920 and executed by the processors 810, 910. The memories 820, 920 can be implemented inside or outside the processors 810, 910. In the case of being implemented outside, the memories 820, 920 can be communicatively coupled to the processors 810, 910 via various means known in the art.

[0141] From the exemplary systems described herein, methods that can be implemented in accordance with the disclosed subject matter have been described with reference to several flowcharts. Although for simplicity purposes these methods are shown and described as a series of steps or modules, it should be understood and appreciated that the claimed subject matter is not limited by the order of the steps or modules, as some steps may occur in a different order than depicted and described herein or concurrently with other steps. Additionally, those skilled in the art should understand that the steps illustrated in the flowcharts are not exclusive and may include other steps, or one or more steps in the exemplary flowcharts may be deleted without affecting the scope and spirit of the present disclosure.

Claims

1. A method, comprising: Enter the connection mode; When in the connection mode, send a request message to the network including timing information for at least one uplink resource; Receive a Radio Resource Control (RRC) connection release message from the network including an uplink resource configuration, wherein the uplink resource configuration includes: i) Information for the at least one uplink resource and information for periodicity, wherein the at least one uplink resource occurs periodically based on the periodicity; and ii) Information for an active duration during which transmissions using the at least one uplink resource are valid; After receiving the RRC connection release message, save the uplink resource configuration that needs to be maintained; and During the active duration, perform the transmission to the network using the at least one uplink resource, wherein the at least one uplink resource is valid in a specific cell, and wherein the transmission includes Physical Uplink Shared Channel (PUSCH) transmission.

2. The method according to claim 1, wherein, The timing information is related to the timing of a starting uplink resource among the at least one uplink resources.

3. The method according to claim 1, further comprising: Receive information on a timing offset related to the timing of a starting uplink resource among the at least one uplink resources.

4. The method according to claim 1, further comprising: Send a first message to the network, the first message including a first parameter notifying a first semi-persistent scheduling (SPS) timing for a logical channel; After sending the first message including the first parameter notifying the first SPS timing to the network, determine that the first SPS timing needs to be changed to a second SPS timing for the logical channel; and Send a second message to the network, the second message including a second parameter notifying the second SPS timing at the change of the first SPS timing.

5. The method according to claim 1, wherein, The RRC connection release message further includes an interval of the at least one uplink resource and a Radio Network Temporary Identifier (RNTI) associated with the at least one uplink resource.

6. The method according to claim 1, wherein, The RRC connection release message further includes a Physical Uplink Control Channel (PUCCH) configuration.

7. The method according to claim 1, further comprising: Resume a suspended radio bearer for a specific logical channel, wherein the at least one uplink resource is used for data of the specific logical channel configured by the network.

8. The method according to claim 7, wherein, After receiving the RRC connection release message, send a buffer status report via a random access procedure to notify the network of the amount of uplink data available for transmission through the specific logical channel.

9. The method according to claim 1, wherein, The uplink resource configuration further includes information on the specific cell for which the at least one uplink resource is valid.

10. A wireless device, comprising: Transceiver; Memory that stores instructions; and At least one processor operably coupled to the transceiver and the memory, wherein the at least one processor executes the instructions to perform operations, the operations including: Enter the connection mode; When in the connection mode, send a request message to the network including timing information for at least one uplink resource; Receive a Radio Resource Control (RRC) connection release message including uplink resource configuration from the network, wherein the uplink resource configuration includes: i) information for the at least one uplink resource and information for periodicity, wherein the at least one uplink resource occurs periodically based on the periodicity; and ii) information for an active duration during which transmissions using the at least one uplink resource are valid; After receiving the RRC connection release message, save the uplink resource configuration that needs to be maintained; and Perform the transmission to the network using the at least one uplink resource during the active duration, wherein the at least one uplink resource is valid in a specific cell, and wherein the transmission includes Physical Uplink Shared Channel (PUSCH) transmission.

11. The wireless device according to claim 10, wherein, The timing information is related to the timing of the starting uplink resource among the at least one uplink resource.

12. The wireless device according to claim 10, wherein, The at least one processor is further configured to control the transceiver to receive information on a timing offset related to the timing of the starting uplink resource among the at least one uplink resource.

13. The wireless device according to claim 10, wherein, The at least one processor is further configured to: Control the transceiver to send a first message to the network, the first message including a first parameter notifying a first semi-persistent scheduling (SPS) timing for a logical channel; After sending the first message including the first parameter notifying the first SPS timing to the network, determine that the first SPS timing needs to be changed to a second SPS timing for the logical channel; and Control the transceiver to send a second message to the network, the second message including a second parameter notifying the second SPS timing at the time of the change of the first SPS timing.

14. The wireless device according to claim 10, wherein, The RRC connection release message further includes the interval of the at least one uplink resource and a Radio Network Temporary Identifier (RNTI) related to the at least one uplink resource.

15. The wireless device according to claim 10, wherein, The RRC connection release message further includes Physical Uplink Control Channel (PUCCH) configuration.

16. The wireless device according to claim 10, wherein, The at least one processor is further configured to resume a suspended radio bearer for a specific logical channel, and wherein the at least one uplink resource is used for data of the specific logical channel configured by the network.

17. The wireless device according to claim 16, wherein, After receiving the RRC connection release message, send a buffer status report via a random access procedure to notify the network of the amount of uplink data available for transmission through the specific logical channel.

18. The wireless device according to claim 10, wherein, The uplink resource configuration further includes information on the specific cell for which the at least one uplink resource is valid.

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