BR112016025491B1 - RESOURCE ALLOCATION CONTROL FOR LONG-TERM EVOLVING DEVICE-TO-DEVICE DISCOVERY - Google Patents

Abstract

RESOURCE ALLOCATION CONTROL FOR LONG-TERM EVOLVING DEVICE-TO-DEVICE DISCOVERY. A method, an apparatus and a computer program product for wireless communication are provided. The device may be a UE The UE determines whether system information is received for D2D communication. Furthermore, the UE establishes at least one indicator based on the system information when the system information is received. Additionally, the UE determines the D2D capabilities based on the at least one indicator.

Description

CROSS REFERENCE TO RELATED ORDER(S)

[0001] This application claims the benefit of United States Provisional Application Serial No. 61/987,839, entitled “RESOURCE ALLOCATION CONTROL FOR LONG TERM EVOLUTION DEVICE-TO-DEVICE DISCOVERY” and filed on May 2, 2014, and Application for United States Patent No. 14/596,146, entitled “RESOURCE ALLOCATION CONTROL FOR LONG TERM EVOLUTION DEVICE-TO-DEVICE DISCOVERY” and filed on January 13, 2015, which are hereby expressly incorporated in their entirety by reference.

BACKGROUND FIELD

[0002] The present disclosure relates generally to communication systems, and more specifically, to controlling resource allocation for device-to-device discovery of long-term evolution.

BACKGROUND

[0003] Wireless communication systems are widely used to provide various telecommunications services such as telephony, video, data, message exchange, and broadcasts. Typical wireless communication systems may employ multiple access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmission capacity). Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, frequency division multiple access (FDMA) systems, frequency division multiple access systems (OFDMA), single carrier frequency division multiple access systems (SC-FDMA), and time division synchronous code division multiple access systems (TD-SCDMA).

[0004] These multiple access technologies have been adopted in various telecommunications standards to provide a common protocol that enables different wireless devices to communicate at a municipal, national, regional and even global level. An example of an emerging telecommunications standard is Long Term Evolution (LTE). LTE is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) standard promulgated by the Third Generation Partnership Project (3GPP). These are designed to support better mobile broadband Internet access through improved spectral efficiency, lower costs, improved services, making use of new spectrum, and better integration with other open standards using OFDMA on the downlink (DL), SC-FDMA on the uplink (UL), and multiple-input, multiple-output (MIMO) antenna technology. However, as demand for mobile broadband access continues to increase, there is a need for additional improvements in LTE technology. Preferably, these enhancements should be applicable to other multiple access technologies and to telecommunications standards that employ those technologies.

SUMMARY

[0005] In one aspect of the disclosure, a method, a computer program product, and an apparatus are provided. The apparatus may be user equipment for wireless communication. The apparatus determines whether system information is received for device-to-device communication. The device establishes at least one indicator based on system information. The apparatus determines D2D capabilities based on at least one indicator.

[0006] A first layer of the UE can receive the system information and can establish the at least one indicator, and a second layer that is higher than the first layer can check the at least one indicator and can request that the first layer determine D2D capabilities. The first layer may be a radio resource control (RRC) layer, and the second layer may be a proximity-based service protocol (ProSe) layer. The system information may be determined to have been received for D2D communication, and the apparatus may determine whether a set of D2D common resources is indicated in the system information, and may determine a radio resource control (RRC) state of the UE , wherein the at least one indicator can be established based on whether the set of D2D common resources is indicated in the system information, and based on the determined state of RRC. The set of D2D common resources may be determined to be indicated in the system information, and the RRC state may be determined to be an RRC idle state, and the apparatus may set the at least one indicator by setting a first indicator of the at least an indicator to indicate to the second layer that a request for an allocation of D2D resources is not required. The apparatus may set the at least one indicator by setting a second indicator of the at least one indicator to indicate that D2D communication is supported. The apparatus may determine from the at least one indicator that D2D communication is supported, and that a request for an allocation of D2D resources is not required, and may determine the D2D resources upon determining to use the set of common D2D resources indicated in the information system for D2D communication. The set of D2D common resources may be determined to be indicated in the system information, and the RRC state may be determined to be an RRC connected state, and the apparatus may set the at least one indicator by setting a first indicator of the at least an indicator to indicate that a D2D resource allocation request is required. The apparatus may set the at least one indicator by setting a second indicator of the at least one indicator to indicate that D2D communication is supported. The apparatus may determine from the at least one indicator that D2D communication is supported, and that a request for an allocation of D2D resources is required, and may determine the D2D resources upon request, at the second layer, that the first layer requests a allocating the D2D resources from a serving base station, and upon receiving the allocation of the D2D resources from the serving base station, wherein the determined D2D resources may be the allocated, received D2D resources. The apparatus may determine from the at least one indicator that D2D communication is supported, and that a request for an allocation of D2D resources is required, and may determine the D2D resources upon request, at the second layer, that the first layer requests the performing D2D communication with a D2D resource pool from a serving base station, and upon receiving an acknowledgment from the base station that the D2D resource pool is reserved for D2D communication. The set of common D2D resources may be determined to be not indicated in the system information, and the RRC state may be determined to be an RRC inactive state, and the apparatus may establish the at least one indicator by setting a first indicator of the at least at least one indicator to indicate to the second layer that a request for an allocation of D2D resources is required. The apparatus may set the at least one indicator by setting a second indicator of the at least one indicator to indicate that D2D communication is supported. The apparatus may determine from the at least one indicator that D2D communication is supported, and that a request for an allocation of D2D resources is required, and may determine the D2D resources upon switching from the RRC idle state to an RRC connected state, upon request at the second layer that the first layer requests an allocation of the D2D resources from a serving base station, and upon receipt of the allocation of the D2D resources from the serving base station, wherein the determined D2D resources may be the D2D resources allocated received. The apparatus may control, via the second layer, a third layer that is higher than the first layer to cause the first layer to switch from the RRC idle state to the RRC connected state. The third layer can be a non-access stratum (NAS) layer. The set of D2D common resources may be determined to be not indicated in the system information, and the RRC state may be determined to be an RRC connected state, and the apparatus may establish the at least one indicator by setting a first indicator of the at least at least one indicator to indicate to the second layer that a request for an allocation of D2D resources is required. The apparatus may establish the at least one indicator by establishing a second indicator of the at least one indicator to indicate that D2D communication is supported. The apparatus may determine from the at least one indicator that D2D communication is supported, and that a request for an allocation of D2D resources is required, and may determine the D2D resources upon request, at the second layer, that the first layer requests a allocating the D2D resources from a serving base station, and upon receiving the allocation of the D2D resources from the serving base station, wherein the determined D2D resources are the received allocated D2D resources. The apparatus may determine from the at least one indicator that D2D communication is supported, and that a request for an allocation of D2D resources is required, and may determine the D2D resources upon request, at the second layer, that the first layer requests the performing D2D communication with a D2D resource pool from a serving base station, and upon receiving an acknowledgment from the base station that the D2D resource pool is reserved for D2D communication. The system information can be determined to have been received for D2D communication, a set of common D2D resources can be indicated in the system information, and the apparatus can perform D2D communication using the set of D2D common resources, it can stop D2D communication through of the D2D common resource set, and may change from the RRC inactive state to an RRC connected state, wherein the at least one indicator may be established from the change from the RRC inactive state to the RRC connected state, and in that the apparatus may establish the at least one indicator by setting a first indicator of the at least one indicator to indicate that a request for allocation of D2D resources is required. The apparatus may set the at least one indicator by setting a second indicator of the at least one indicator to indicate that D2D communication is supported. The apparatus may determine from the at least one indicator that D2D communication is supported, and that a request for an allocation of D2D resources is required, and may determine the D2D resources by determining, at the second layer, that no D2D resources are available. available upon request at the second layer, that the first layer requests an allocation of D2D resources from a serving base station, and upon receipt of the allocation of D2D resources from the serving base station, wherein the determined D2D resources are the D2D resources allocated, received. The system information may be determined to have been received for D2D communication, a set of common D2D resources may not be indicated in the system information, the device may perform D2D communication using an allocated set of D2D resources, it may receive a revocation of use of the allocated set of D2D resources, and may establish the at least one indicator by defining a first indicator of the at least one indicator to indicate whether a request for allocation of the D2D resources is required. The apparatus may establish the at least one indicator by setting a second indicator of the at least one indicator to indicate whether D2D communication is supported. The apparatus may determine from the at least one indicator that D2D communication is supported, and that a request for an allocation of D2D resources is required, and may determine the D2D resources upon determining at the second layer that no D2D resources are available. upon request, in the second layer, that the first layer requests an allocation of D2D resources from a serving base station, and upon receipt of the allocation of D2D resources from the serving base station, wherein the determined D2D resources are the resources D2D allocated received. System information may be determined not to have been received for D2D communication, and the apparatus may establish the at least one indicator by setting an indicator of the at least one indicator indicating that D2D communication is not supported, wherein the D2D resources can be determined to be a null set. The device can transmit the signals in D2D resources.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a diagram illustrating an example of a network architecture.

[0008] Figure 2 is a diagram of an example of an access network.

[0009] Figure 3 is a diagram of an example of a DL frame structure in LTE.

[0010] Figure 4 is a diagram of an example of a UL frame structure in LTE.

[0011] Figure 5 is a diagram illustrating an example of a radio protocol architecture for the user and control planes.

[0012] Figure 6 is a diagram illustrating an example of an Evolved Node B (eNB) and user equipment in an access network.

[0013] Figure 7 is a diagram of a device-to-device communication system.

[0014] Figure 8 is a block diagram illustrating various layers that make up a stack of a UE involved in device-to-device (D2D) communication, the functions of the layers, and the various interfaces between them.

[0015] Figure 9 is a first diagram illustrating exemplary message exchange between UE layers and an eNB.

[0016] Figure 10 is a second diagram illustrating exemplary message exchange between UE layers and an eNB.

[0017] Figure 11 is a third diagram illustrating exemplary message exchange between UE layers and an eNB.

[0018] Figure 12 is a fourth diagram illustrating exemplary message exchange between UE layers and an eNB.

[0019] Figure 13 is a fifth diagram illustrating exemplary message exchange between UE layers and an eNB.

[0020] Figure 14 is a flowchart of a wireless communication method.

[0021] Figure 15 is a diagram illustrating a first wireless communication method.

[0022] Figure 16 is a conceptual data flow diagram illustrating the flow of data between different modules, means, components in an exemplary apparatus.

[0023] Figure 17 is a diagram illustrating an example of a hardware implementation for an apparatus employing a processing system.

DETAILED DESCRIPTION

[0024] The detailed description presented below in connection with the attached drawings is intended to be a description of various configurations and is not intended to represent the configurations in which the concepts described herein can be practiced. The detailed description includes specific details for the purpose of providing a complete understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts can be practiced without these specific details. In some cases, well-known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

[0025] Various aspects of telecommunications systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the detailed description that follows and illustrated in the accompanying drawings by various blocks, modules, components, steps, circuits, processes, algorithms, etc. (collectively referred to as “elements”). These elements can be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends on the specific application and design constraints imposed on the overall system.

[0026] As an example, an element, or any portion of an element, or any combination of the elements can be implemented with a “processing system”, which includes one or more processors. Examples of processors include microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate arrays (FPGA), programmable logic devices (PLD), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionalities described throughout this description. One or more processors in the processing system may execute the software. Software should be interpreted broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects , executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0027] Consequently, in one or more exemplary embodiments, the described functions can be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored in or encoded as one or more code instructions or in a computer-readable medium. Computer readable media include computer storage media. Storage media can be any available medium that can be accessed by a computer. By way of example, and not as a limitation, such computer-readable media may comprise a random access memory (RAM), a read-only memory (ROM), an electrically erasable programmable ROM (EEPROM), a compact disk ROM ( CD-ROM) or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to transport or store the desired program code in the form of instructions or data structures, and that can be accessed by a computer. Combinations of the foregoing should also be included within the scope of computer-readable media.

[0028] Figure 1 is a diagram illustrating an LTE network architecture 100. The LTE network architecture 100 may be referred to as an Evolved Packet System (EPS) 100. The EPS 100 may include one or more user equipment ( UE) 102, an Evolved UMTS Terrestrial Radio Access Network (e-UTRAN) 104, an Evolved Packet Core (EPC) 110 and an Operator's Internet Protocol (IP) Services. The EPS can interconnect with other access networks, but for simplicity these entities/interfaces are not shown. As shown, EPS provides packet switching services, however, as those skilled in the art will readily appreciate, the various concepts presented throughout this disclosure can be extended to networks that provide circuit switching services.

[0029] The E-UTRAN includes the evolved node B (ENB) 106 and another eNB 108, and may include a Multicast Coordination Entity (MCE) 128. The eNB 106 provides protocol terminations to and from user control planes to the UE 102 The eNB 106 may be connected to the other via an intermediate link eNB 108 (e.g., an X2 interface). The MCE 128 allocates radio frequency/time resources to Evolved Multimedia Broadcast Multicast Service (MBMS) (eMBMS), and determines the radio configuration (e.g., the modulation and coding scheme (MCS)) for the eMBMS. The MCE 128 may be a separate entity or part of the eNB 106. The eNB 106 may also be referred to as a base station, a Node B, an access point, a transceiver base station, a radio base station, a transceiver radio, a transceiver function, a basic service set (BSS), an extended service set (ESS), or some other suitable terminology. The eNB 106 provides an access point to the EPC 110 for a UE 102. Examples of UEs 102 include a cellular phone, a smart phone, a (SIP) Session Initiation Protocol telephone, a laptop, a personal digital assistant (PDA) , a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g. MP3 player), a camera, a game console, a tablet or any other device similar operation. The UE 102 may also be referred to by those skilled in the art as a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, wireless communications wired device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, an apparatus, a user agent, a mobile client, a client, or some other appropriate terminology.

[0030] The eNB 106 is connected to the EPC 110. The EPC 110 may include a Mobility Management Entity (MME) 112, a Home Subscriber Server (HSS) 120, another MME 114, a Dose portal 116, a Multimedia Broadcast Multicast Service (MBMS) gateway 124, a Broadcast Multicast Service Center (BM-SC) 126, and a Packet Data Network (PDN) gateway 118. The MME 112 is the control node that processes signaling between o UE 102 and 110 of the EPC. Generally, the MME 112 provides carrier and connection management. All user IP packets are transferred through the server portal 116, which in turn is connected to the PDN portal 118. The PDN portal 118 provides UE IP address allocation as well as other functions. The PDN portal 118 and the BM-SC 126 are connected to the IP Services 122. The IP Services 122 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), the PS Streaming Service (PSS), and/or other IP services. The BM-SC 126 can provide functions for provisioning and delivering MBMS user services. The BM-SC 126 can serve as an entry point for content provider MBMS transmission, can be used to authorize and initiate MBMS bearer services within a PLMN, and can be used to schedule and deliver MBMS transmissions. The MBMS portal 124 may be used to distribute MBMS traffic to eNBs (e.g., 106, 108) belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area transmitting a particular service, and may be responsible for session management ( start/stop) and to collect information related to eMBMS billing.

[0031] Figure 2 is a diagram illustrating an example of an access network 200 in an LTE network architecture. In this example, the access network 200 is divided into a number of cellular regions (cells) 202. One or more lower power class eNB 208 may have cellular regions 210 that overlap with one or more of the cells 202. The Lower power eNB 208 may be a femto cell (e.g., home eNB (HeNB)), pico cell, micro cell, or remote radio head (RRH). The eNB macros 204 are individually assigned to a respective cell 202 and are configured to provide an access point to the EPC 110 for all UEs 206 in cells 202. There is no centralized controller, in this example, of an access network 200, but a centralized controller can be used in alternative configurations. The eNB 204 is responsible for all radio related functions including carrier radio control, admission control, mobility control, scheduling, security and connectivity to the gateway serving 116. An eNB may support one or multiple (e.g., three ) cells (also referred to as a sectors). The term “cells” may refer to the smaller coverage area of an eNB and/or an eNB subsystem serving a particular coverage area. Furthermore, the terms “eNB”, “base station”, and “cells” may be used interchangeably here.

[0032] The multiple access and modulation scheme employed by access network 200 may vary depending on the particular telecommunications standard to be deployed. In LTE applications, OFDM is used in DL and SC-FDMA is used in UL to support both frequency division duplex (FDD) and time division duplex (TDD). As those skilled in the art will readily appreciate from the detailed description below, the various concepts presented here are well suited for LTE applications. However, these concepts can be easily extended to other telecommunications standards that employ modulation and other multiple access techniques. By way of example, these concepts can be extended to Evolution-Data Optimized (EV-DO) or Ultra Mobile Broadband (UMB). EV-DO and UMB are air interface standards promulgated by the 3rd Generation Partnership Project 2 (3GPP2) as part of the CDMA2000 family of standards and employ CDMA to provide broadband Internet access to mobile stations. These concepts can also be extended to Universal Terrestrial Radio Access (UTRA) employing Wideband-CDMA (W-CDMA) and other CDMA variants such as TD-SCDMA; Global System for Mobile Communications (GSM) employing TDMA; and Evolved UTRA (E-UTRA), IEEE 802.11 (WiFi), IEEE 802.16 (WiMAX), IEEE 802.20, and Flash-OFDM using OFDMA. UTRA, E-UTRA, UMTS, LTE and GSM are described in organization documents 3 GPP. CDMA2000 and UMB are described in documents from the 3GPP2 organization. The actual wireless communications standard and multiple access technology employed will depend on the specific application and the overall design limits imposed on the system.

[0033] The eNB 204 may have multiple antennas that support MIMO technology. The use of MIMO technology allows the eNB 204 to explore the spatial domain to support spatial multiplexing, beamforming, and transmission diversity. Spatial multiplexing can be used to transmit different data streams simultaneously on the same frequency. Data streams may be transmitted to a single UE 206 to increase the data rate or from multiple UEs 206 to increase overall system capacity. This is achieved by spatially pre-coding each data stream (i.e., applying a scaling of one amplitude and one phase) and then transmitting each pre-coded spatial stream through multiple transmit antennas in the DL. . The spatially pre-coded data streams arrive at the UE(s) 206 with different spatial signatures, which allows each of the UE(s) 206 to retrieve one or more data streams destined for that UE 206. In the UL, each UE 206 transmits a spatially pre-coded data stream, which allows the eNB 204 to identify the source of each spatially pre-coded data stream.

[0034] Spatial multiplexing is generally used when channel conditions are good. When channel conditions are less favorable, beamforming can be used to focus the transmission energy in one or more directions. This can be achieved by spatially pre-coding the data for transmission across multiple antennas. To achieve good coverage at the cell edges, a single stream beamforming transmission can be used in combination with transmission diversity.

[0035] In the detailed description below, the various aspects of an access network will be described with reference to a MIMO system supporting OFDM in the DL. OFDM is a spread spectrum technique that modulates data over a number of sub-carriers within an OFDM symbol. The subcarriers are spaced at precise frequencies. The spacing provides “orthogonality” that allows a receiver to recover data from the subcarriers. In the time domain, a guard interval (e.g. cyclic prefix) can be added to each OFDM symbol to combat inter-symbol interference - OFDM. The UL can use SC-FDMA in the form of a DFT propagation OFDM signal to compensate for the high peak-to-average power ratio (PAPR).

[0036] Figure 3 is a diagram of 300 illustrating an example of a frame structure in DL LTE. One frame (10 ms) can be divided into 10 equally sized subframes. Each subframe can include two consecutive time slots. A resource grid can be used to represent two time intervals, including each time interval of a resource block. The resource grid is divided into several resource elements. In LTE, by a normal cyclic prefix, a resource block contains 12 consecutive subcarriers in the frequency domain and 7 consecutive OFDM symbols in the time domain, for a total of 84 resource elements. For an extended cyclic prefix, a resource block contains 12 consecutive subcarriers in the frequency domain and 6 consecutive OFDM symbols in the time domain, for a total of 72 resource elements. Some of the resource elements, indicated as R 302, 304, include DL reference signals (DL-RS). DL-RS includes cell-specific RS (CRS) (also sometimes called common RS) 302 and UE-specific RS (UE-RS) 304. UE-RS 304 is transmitted in the resource blocks where the physical channel corresponding shared DL (PDSCH) is mapped. The number of bits carried by each resource element depends on the modulation scheme. Thus, the more resource blocks that a UE receives and the higher the modulation scheme, the higher the data rate for the UE.

[0037] Figure 4 is a diagram of 400 illustrates an example of a UL frame structure in LTE. The resource blocks available to the UL can be divided into a data section and a control section. The control section can be formed at both ends of the bandwidth system and can have a configurable size. Resource blocks in the control section can be assigned values for transmitting control information. The data section can include all resource blocks not included in the control section. The UL frame structure results in the data section including contiguous subcarriers, which may allow a single UE to be assigned all contiguous subcarriers in the data section.

[0038] A UE may be assigned resource blocks 410a, 410b in the control section to transmit control information to an eNB. The UE may also be assigned resource blocks 420a, 420b in the data section to transmit data to the eNB. The UE may transmit control information on a UL physical control channel (PUCCH) over the resource blocks assigned in the control section. The UE may transmit data or both data and control information on a physical UL channel (PUSCH) over the resource blocks assigned in the shared data section. A UL transmission can span both partitions of a subframe and can hop across frequency.

[0039] A set of resource blocks may be used to perform initial system access and achieve UL synchronization on a physical random access channel (PRACH) 430. The PRACH 430 carries a random sequence and cannot carry any UL/ signaling data. Each random access preamble occupies a bandwidth corresponding to six consecutive resource blocks. The starting frequency is specified by the network. That is, transmission of the random access preamble is restricted to certain time and frequency resources. There is no frequency hopping for PRACH. The PRACH attempt is performed in a single subframe (1 ms), or in a sequence of some adjacent subframes, and a UE may make a single PRACH attempt per frame (10 ms).

[0040] Figure 5 is a diagram of 500 illustrates an example of a radio protocol architecture for the control and user planes in LTE. The radio protocol architecture for the UE and the eNB is shown with three layers: Layer 1, Layer 2, Layer 3, and Layer A (LI layer) is the lowest layer and implements the various signal processing functions of the physical layer. . The LI layer will be referred to herein as the physical layer 506. Layer 2 (L2 layer) is 508 on top of the physical layer 506 and is responsible for the connection between the UE and eNB through the physical layer 506.

[0041] In the user plane, the L2 layer 508 includes a medium access control (MAC) sublayer 510, a radio link control (RLC) sublayer 512, and a packet data convergence protocol (PDCP) 514 sublayer, which are terminated in the eNB on the network side. Although not shown, the UE may have several upper layers above the L2 layer 508, including a network layer (e.g., IP layer) that is terminated at the PDN gateway 118 on the network side, and an application layer that is terminated at the other end of the link (e.g., far end of the UE, server, etc.).

[0042] The PDCP sublayer 514 provides multiplexing between different radio carriers and logical channels. The PDCP sublayer 514 also provides header compression for upper layer data packets to reduce radio transmission overhead, security by encrypting the data packets, and handover support for UEs between eNBs. The RLC sublayer 512 provides segmentation and reassembly of upper layer data packets, retransmission of lost data packets, and reordering of data packets to compensate for out-of-order reception due to hybrid automatic repeat request (HARQ). The MAC sublayer 510 provides multiplexing between logical and transport channels. The MAC sublayer 510 is also responsible for allocating the various radio resources (e.g., resource blocks) in a cell between the UEs. The MAC 510 sublayer is also responsible for HARQ operations.

[0043] In the control plane, the radio protocol architecture for the UE and eNB is substantially the same for the physical layer 506 and the L2 layer 508 with the exception that there is no header compression function for the control plane. control. The control plane also includes a radio resource control (RRC) sublayer 516 at layer 3 (L3 layer). The RRC sublayer 516 is responsible for obtaining radio resources (e.g., radio bearers) and for configuring the lower layers using RRC signaling between the eNB and the UE.

[0044] Figure 6 is a block diagram of an eNB 610 communicating with a UE 650 in an access network. In DL, packets from the upper layer of the network core are provided to a controller/processor 675. The controller/processor 675 implements the functionality of the L2 layer. In the DL, the controller/processor 675 provides header compression, encryption, packet segmentation and reordering, multiplexing between logical and transport channels, and radio resource allocations to the UE 650 based on various priority indicators. The controller/processor 675 is also responsible for HARQ operations, retransmission of lost packets, and signaling to the UE 650.

[0045] The transmission processor (TX) 616 implements various signal processing functions for the LI layer (i.e., the physical layer). Signal processing functions include coding and interleaving to facilitate forward error correction (FEC) in the UE 650 and mapping to signal constellations based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M phase shift keying (M-PSK), M quadrature amplitude modulation (M-QAM)). The coded and modulated symbols are then divided into parallel streams. Each stream is then mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., the pilot) in the time and/or frequency domain, and then combined together using an Inverse Fast Fourier Transform (IFFT) to produce a physical channel that carries an OFDM time domain symbol stream. The OFDM stream is spatially pre-coded to produce multiple spatial streams. Channel estimates from a channel estimator 674 can be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimate may be derived from a reference signal and/or channel condition return transmitted by the UE 650. Each spatial stream may then be provided to a different antenna 620 via a separate transmitter 618TX. Each 618TX transmitter can modulate an RF carrier with a respective spatial flow for transmission.

[0046] In UE 650, each receiver 654RX receives a signal through its respective antenna 652. Each receiver 654RX recovers modulated information over an RF carrier and provides the information to the receive processor (RX) 656. The RX processor 656 implements various L1 layer signal processing functions. The RX processor 656 can perform spatial processing on the information to retrieve spatial streams destined for the UE 650. If multiple spatial streams are destined for the UE 650, they can be combined with the RX processor 656 into a single OFDM symbol stream. The 656 RX processor then converts the stream of OFDM symbols from the time domain to the frequency domain using a Fast Fourier Transform (FFT). The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the points in the signal constellation most likely transmitted by the eNB 610. These indicative decisions may be based on channel estimates calculated by the channel estimator 658. The decisions then decoded and reverse interleaved to recover the data and control signals that were originally transmitted by the eNB 610 on the physical channel. Data and control signals are then supplied to the 659 controller/processor.

[0047] Controller/processor 659 implements the L2 layer. The controller/processor may be associated with a memory 660 that stores program codes and data. Memory 660 may be referred to as a computer-readable medium. In UL, the 659 controller/processor provides demultiplexing between transport and logical channels, packet reassembly, decoding, header decompression, control signal processing to recover packets from the upper layer of the core network. The upper layer packets are then provided to a data sink 662, which represents all layers above the L2 protocol layer. Various control signals may also be provided to the data sink 662 for L3 processing. The controller/processor 659 is also responsible for detecting errors using a negative acknowledgment (NACK) acknowledgment (ACK) protocol and/or for supporting HARQ operations.

[0048] In the UL, a data source 667 is used to provide upper layer packets to the controller/processor 659. The data source 667 represents all protocol layers above the L2 layer. Similar to the functionality described in connection with DL transmission by the eNB 610, the controller/processor 659 implements the L2 layer for the user plane and the control plane, providing header compression, coding, packet segmentation and reordering. and multiplexing between logical and transport channels based on the allocation of radio resources by the eNB 610. The controller/processor 659 is also responsible for HARQ operations, retransmission of lost packets, and signaling to the eNB 610.

[0049] Channel estimates obtained by a channel estimator 658 from a reference or return signal transmitted by the eNB 610 may be used by the TX processor 668 to select appropriate modulation and coding schemes, and to facilitate spatial processing. . The spatial streams generated by the TX processor 668 may be provided to the antenna 652 through different separate transmitters 654TX. Each 654TX transmitter can modulate an RF carrier with a respective spatial flow for transmission.

[0050] The UL transmission is processed in the eNB 610 in a manner similar to that described in connection with the receiver function in the UE 650. Each receiver 618RX receives a signal through its respective antenna 620. Each receiver 618RX recovers the modulated information about an RF carrier and provides the information to an RX 670 processor. The RX 670 processor can apply the L1 layer.

[0051] Controller/processor 675 implements the L2 layer. The controller/processor 675 may be associated with a memory 676 that stores program codes and data. Memory 676 may be referred to as a computer-readable medium. In the UL, the controller/processor 675 provides demultiplexing between transport and logical channels, packet reassembly, decryption, header decompression, control signal processing to recover upper layer packets from the UE 650. The upper layer packets controller/processor 675 may be provided for the base network. The 675 controller/processor is also responsible for detecting errors using a NACK ACK protocol and/or for supporting HARQ operations.

[0052] Figure 7 is a diagram of a device-to-device communications system 700. The device-to-device communications system 700 includes a plurality of wireless devices 704, 706, 708, 710. The device-to-device communications system for device 700 may overlay a cellular communications system, such as, for example, a remote area network (WWAN). Some of the wireless devices 704, 706, 708, 710 may communicate together in device-to-device communication using the WWAN DL/UL spectrum, some may communicate with the base station 702, and some may do both. For example, as shown in Figure 7, wireless devices 708, 710 are in device-to-device communication and wireless devices 704, 706 are in device-to-device communication. The wireless devices 704, 706 are also communicating with the base station 702.

[0053] The exemplary methods and apparatus discussed below are applicable to any of a variety of wireless device-to-device communication systems, such as, for example, a wireless device-to-device communication system based on FlashLinQ, WiMedia, Bluetooth, ZigBee, or Wi-Fi based on the IEEE 802.11 standard. To simplify the discussion, exemplary methods and devices are discussed within the context of LTE. However, those of ordinary skill in the art will understand that the exemplary methods and apparatus are applicable more generally to a variety of other wireless device-to-device communication systems.

[0054] Exemplary embodiments generally provide methods and apparatus for allowing a UE to communicate with another UE (e.g., allowing the UE to advertise something over the LTE band, which is received by another UE).

[0055] Figure 8 is a block diagram 800 depicting various layers that form a stack of a UE 802 involved in D2D communication, such as discovered D2D communication, their functions, and various interfaces therebetween. The various layers of the UE 802 stack include a ProSa (Proximity Based Service) protocol 804, a non-access stratum (NAS) layer 806, an RRC layer/sublayer 808, and a MAC layer/sublayer 810. Various other layers /sublayers may exist in the UE 802 stack of exemplary embodiments. However, the present detailed description will focus on the ProSa 804 protocol, the NAS layer 806, the RRC layer 808, and the MAC layer 810, and various channels of interaction between the different layers.

[0056] Below the ProSa protocol 804 is the NAS layer 806, which is capable of controlling the state transition of the UE 802 (e.g., from an “idle state” to a “connected” state). However, the NAS layer 806 is typically unaware of D2D operation. Furthermore, the NAS 806 layer is shared and affected by other applications.

[0057] Below the NAS layer 806 is the RRC layer 808, which has information regarding the requirements for the allocation of D2D radio resources, and which also has information regarding the current state of the UE 802, but is unable to control the transition of the EU State. The RRC layer 808 is capable of controlling the radio resources of the UE 802, and is capable of communicating with a base station/eNB 812 in the network. Thus, radio resource allocation is only available to, and controlled by, the RRC layer 808. Additionally, radio resource allocation may not be immediately known to the NAS layer 806 or to the ProSa Protocol 804.

[0058] Finally, below the RRC layer 808 is the MAC layer 810, which is responsible for transmission scheduling for the UE 802. That is, the MAC layer 810 effectively decides when any message to be transmitted by the UE 802 passes over the air , which can be predicted through communication with the ProSa protocol 804. Furthermore, the RRC layer 808 can control MAC radio resources of the MAC layer 810 according to the system information provided by the network, and according to other events, such as will be discussed below.

[0059] Embodiments address the fact that information regarding available D2D resources, and information regarding a connection state of a generic UE (i.e., connected or idle), is known to only select layers of the stack of the aforementioned EU. Furthermore, the ability to control, or transition, said UE from one state to the next (e.g., from the idle state to the connected state) may be possessed only by one or more layers.

[0060] For example, a control protocol (e.g., the ProSa Protocol) corresponding to an upper layer of a generic UE is aware of the timing and information constraints corresponding to D2D transmission, but does not have direct access to the corresponding information for the lower layers (such as the RRC layer).

[0061] In exemplary embodiments, under certain circumstances, the ProSa Protocol 804 may exchange information with the NAS layer 806 (e.g., via interface 822), with the RRC layer 808 (e.g., via interface 821), and with the MAC layer 810 (e.g., via interface 823), while the RRC layer 808 may communicate with the NAS layer 806 (e.g., via interface 822'). Additionally, the RRC layer 808 may communicate with the base station/eNB 812.

[0062] The allocation of radio resources to the UE 802 for D2D communication, such as LTE Direct Discovery (LTE-D), may be controlled by the network to which the eNB 812 is connected. Before the UE 802 can communicate directly with another UE (with which the UE 802 seeks to engage in D2D Discovery communication), the UE 802 can obtain network permission through the eNB 812. Once the UE 802 receives network permission, The UE 802 may send the code corresponding to its intended communication over the air to the other UE. By using D2D resources that may be referred to as peer discovery resources, the UE 802 is capable of being discovered by another UE, and is subsequently able to communicate directly with the others using D2D UE resources that may be referred to as communication resources D2D. LTE-D discovery considers three main use cases: 1) when system information (e.g., information contained in a system information block (SIB)) indicates type 1 (i.e., common) resources, 2) when system information only indicates that the network supports LTE-D, and 3) when no system information for D2D is provided. Depending on the use case and the linked/idle state of the UE, the UE may or may not send a message requesting RRC resources (e.g., type 2 (allocated) resources and/or type 1 (common resources)). Following are the three main use cases (1, 2, and 3), and their sub-parts (a, b, and c) for LTE-D discovery.

[0063] Case la) When the system information (e.g., the SIB) for D2D communication indicates Type 1 Resources (e.g., the system information indicates that a set of D2D resources, such as peer common discovery resources or resources of D2D communication, is available through the eNB 812 of a resource pool), and when the UE 802 is in the inactive state (e.g., an RRC inactive state), then the UE 802 may use resources of type 1 indicated for communication D2D discovery method, and no RRC message is required. That is, when the UE 802 is in the idle state, the UE 802 can make use of the information (e.g., resource information) transmitted by the eNB 812, and is able to perform radio resource management without additional communication with the eNB 812.

[0064] Case lb) When the SIB for D2D communication indicates type 1 capabilities, and the UE 802 is in the connected state (e.g., an RRC connected state), then the UE 802 sends an RRC message to the eNB 812 for resource allocation, regardless of whether the UE uses type 1 or type 2 resources. That is, when the UE 802 is in the connected state, the UE 802 requests the network, via the eNB 812, for permission as well as for resource allocation information, to enable the UE 802 to perform D2D discovery communication.

[0065] Case lc) When the SIB for D2D communication indicates Type 1 Resources, and the UE 802 changes from idle state to connected state when using Type 1 resources for peer discovery or D2D communication, the UE 802 may terminate transmission using the current type 1 resources, and may send an RRC message for resource allocation, and may then resume transmission with the allocated resources indicated by the eNB 812.

[0066] Case 2a) When the SIB for D2D communication indicates only that the network supports LTE-D (e.g., whether the network supports peer discovery, or that discovery is supported), but does not indicate any Type 1 resource information , and the UE 802 is in the idle state, the UE 802 may transition to the connected state, and may then send an RRC message to ask the network for resources.

[0067] Case 2b) When the SIB for D2D communication indicates that D2D communication and D2D discovery are supported, but does not indicate any resource information, and the UE 802 is in the connected state, the UE 802 will send an RRC message for allocation of resources.

[0068] Case 2c) When the SIB for D2D communication indicates that D2D communication and D2D discovery are supported, but does not indicate any resource information, and either the UE 802 loses its connection to the network or the eNB 812 revokes the granted resources to UE 802, UE 802 may not continue to use the resources.

[0069] Case 3) When no SIB for D2D is provided (e.g., when the UE 802 is served by a legacy eNB, and is not connected to a network that supports LTE-D), then the UE 802 may not function of D2D transmission, and may interrupt sending code to the MAC layer 810. That is, when the eNB 812 is connected to a network that does not support D2D discovery or D2D communication, the UE 802 cannot engage in D2D communication with the other UE.

[0070] Each of the previous cases (la, lb, lc, 2a, 2b, 2c, and 3) corresponds to one of figures 9-13, and will be discussed in relation to exemplary embodiments in greater detail below.

[0071] Exemplary embodiments provide configurations for the UE 802 to perform radio resource allocation methods for LTE D2D communication or LTE D2D discovery, while still operating within the same schemes, or cases, described above. That is, exemplary embodiments provide methods and apparatus for managing resource allocation for UEs connected to an LTE-D network in various scenarios.

[0072] For example, for the purpose of supporting proper management of D2D resources, exemplary embodiments allow the RRC layer 808 to receive a trigger from a higher layer, such as the NAS layer 806 or the ProSa Protocol 804, wherein the trigger causes the RRC layer 808 to send a “D2D resource request” message to the eNB 812. This scenario will be discussed with reference to cases lb, lc, 2a and 2b.

[0073] Furthermore, exemplary embodiments allow the RRC layer 808 to indicate or communicate some state change events to the ProSa Protocol 804 to thereby allow the ProSa Protocol 804 to decide what actions should be taken. This scenario will be discussed with reference to cases 2c and 3.

[0074] Furthermore, exemplary embodiments consider that the sending of an RRC message (e.g., the sending of the D2D resource request message by the RRC layer 808) is not always accompanied by a state transition of the UE 802. In such a case , involving the NAS layer 806 may not provide any additional benefit, and may reduce the operation efficiency of the UE 802. This scenario will be discussed with reference to cases lb and 2b.

[0075] Referring again to Figure 8, exemplary embodiments provide efficient UE management of resources for LTE D2D communication by providing an interface, or an interaction channel, 821 between the ProSa Protocol 804 and the RRC layer 808 on the UE 802. The interaction channel 821 allows the RRC layer 808 to provide information to the ProSa Protocol 804, which can handle the related state transition of the UE 802 based on the information (as well as based on the state/idle relationship of the NAS layer 806). ).

[0076] In the present embodiment, the information provided by the RRC layer 808 for the ProSa 804 protocol corresponds to: 1) whether the eNB 812 network supports LTE-D (D2D); and 2) whether the RRC layer 808 will require some action by the other layers of the UE 802 to allow the RRC layer 808 to obtain the resources of the eNB 812.

[0077] For each of the cases described above, information may be communicated by the RRC layer 808 of the ProSa Protocol 804 using one or more indicators, thereby allowing the RRC layer 808 to indicate certain states of the UE 802 while communicating a relatively small amount of training. In the present embodiment, the RRC 808 layer communicates the above information to the ProSa 804 protocol, defining the two indicators. For the purposes of this detailed description, these indicators may be referred to as a “Trigger Required” indicator, and a “Discovery Supported” indicator. These two indicators are defined by the RRC layer 808 according to the reading of the RRC layer of the SIB.

[0078] With reference to the figures, three different configurations of the indicators will be discussed. First, a Compatible Discovery indicator is defined (e.g., a corresponding value for the indicator equals 1), and a required trigger indicator is disabled (e.g., a corresponding value for the indicator equals 0) (e.g. example, case there). Second, both the Discovery supported indicator and the required trigger indicator are defined (e.g., cases lb, lc, 2a, 2b, and 2c). Third, the supported discovery indicator is disabled (the required trigger indicator can be enabled or disabled) (for example, case 3). Although the term “supported discovery indicator” is used throughout this specification and in the figures, in other configurations, the “supported discovery indicator” may be a “D2D supported communication indicator” that indicates that D2D communication is supported. over the network.

[0079] Based on the indicators and state of the UE 802 connection, the ProSa Protocol 804 may cause a state transition (e.g., by triggering the NAS layer 806), trigger the RRC layer 808 (e.g., to instruct the RRC 808 to send a resource request), and/or send a command to the MAC layer 810, as will be discussed below.

[0080] Figure 9 is a first diagram 900 of which illustrates exemplary message exchange between UE layers and an eNB. With reference to Figure 9, the above-mentioned case is discussed. In the present case, the network of the eNB 812 supports LTE, and the UE 802 is in an inactive state. Furthermore, the SIB indicates that type 1 is available resources, which indicates that a common set of radio resources is available to the UE 802 to select the desired resources therefrom for D2D communication (e.g., peer discovery). .

[0081] Accordingly, the RRC layer 808 sets the supported discovery indicator (e.g., the supported discovery indicator is set to 1), while the required trigger indicator is disabled (e.g., the required trigger indicator is set to 0 ). This information can be viewed by the ProSa Protocol 804 in accordance with exemplary embodiments. Additionally, the indicators allow the RRC layer 808 to communicate information useful to the ProSa Protocol 804 without communicating information that does not need to be used by the ProSa Protocol 804 (such as information indicating whether the available resources are of type 1 Resources or of type 2 resources).

[0082] Furthermore, radio resources for D2D MAC are configured at MAC layer 810 by RRC layer 808 according to type 1 resources, in accordance with the information contained in the SIB. Then, the RRC layer 808 configures the radio MAC Resources, the ProSa Protocol 804 communicates with the MAC layer 810 through an interface, or interaction channel, 823 (see Figure 8) to obtain a time transmission opportunity (TxOP) according to one or more ProSa Application Codes (ProSa Application Codes) obtained by the ProSa Protocol 804. The interaction channel 823 allows the ProSa Protocol 804 to send a query to the MAC layer 810 so that the ProSa Protocol 804 can know , and the UE 802 can coordinate when sending the intended LTE-D message corresponding to the ProSa application code.

[0083] In the present case, as no state transition of the UE 802 is required for delivery of a message from the UE 802, the ProSa Protocol 804 is able to directly successfully obtain the TXOP of the MAC layer 810 to enable transmission by the UE 802. That is, even if the UE 802 is in an inactive state, as the MAC layer radio resources 810 are established, and as the resources are indicated as type 1 resources, a state transition of the UE 802 to D2D communication or D2D discovery communication is not required.

[0084] When the ProSa Protocol 804 contacts the MAC layer 810, the MAC layer 810 decides what information to send back to the ProSa Protocol 804 regarding transmission time (e.g., what time TxOP to send back), such as The MAC layer 810 needs to assign multiple times to multiple intended messages. That is, the ProSa Protocol 804 communicates with the MAC layer 810 to determine a future time at which the ProSa Protocol 804 can transmit the ProSa application code. Consequently, the MAC layer 810 sends the chosen TxOP time back to the ProSa Protocol 804 so that the MAC layer 810 can assign a specific time that the ProSa Protocol 804 can deliver a message (e.g., a ProSa App Code and Checksum Message Integrity of (MIC )), according to the TxOP time.

[0085] It should be noted that in the present case, although the ProSa Protocol 804 obtains a single TxOP time for a single corresponding ProSa application code, the UE 802 allows multiple ProSa application codes with multiple corresponding respective TXOP times, as will be discussed below.

[0086] Upon receiving a valid TxOP time from the MAC layer 810, the ProSa Protocol 804 decides whether to trigger the NAS layer 806 or the RRC layer 808, as will be discussed further below. Since neither the trigger is required in this case, the ProSa Protocol 804 calculates a message integrity checksum (MIC) (e.g., a security integration check result) for each ProSa application code based on the corresponding TxOP time . After that, the ProSa Protocol 804 sends the application code in ProSa, according to the TxOP requested and obtained time communicated by the MAC layer 810, and the UE 802 sends a D2D communication message (for example, a D2D discovered communication message ) corresponding to the ProSa application code.

[0087] Continuing with reference to figure 9, the aforementioned case lb is discussed. In the present case, the eNB 812 network still supports LTE-D, and the SIB indicates that type 1 resources are available, but the UE 802 has been switched to a connected state.

[0088] In the present case, when the RRC layer 808 has been transferred from the inactive state (e.g., in the case of La) to the connected state, the radio MAC resources are removed from the MAC layer 810 by the RRC layer 808. This is, the RRC layer 808 establishes the supported discovery indicator and the required trigger indicator (for example, the supported discovery indicator and the required trigger indicator are both set to 1), and because the required trigger indicator is newly defined , the RRC layer 808 removes D2D radio resources from the MAC layer 810. Again, the information indicated by the indicators can be seen by the ProSa 804 protocol.

[0089] Unlike the previous case, when the ProSa Protocol 804 attempts to obtain a TxOP time, in accordance with one or more ProSa application codes previously obtained by the ProSa Protocol 804, through its communications with the MAC layer 810, the attempt to get the TxOP time fails. Because no radio discovery capabilities have been configured at the MAC layer 810, the MAC layer 810 uses a “null TxOP time” to indicate to the ProSa Protocol 804 that some action needs to be taken. That is, the MAC layer 810 sends a “null”, or some other indicator, to the ProSa Protocol 804 to indicate that no transmission time is available, thus indicating to the ProSa Protocol 804 that some action needs to be taken, indicating that No radio resources are available during the discovery period.

[0090] Again, the ProSa Protocol 804 decides whether to trigger the NAS layer 806 or the RRC layer 808. Here, because the uncovered indicator and the required trigger indicator supported are both set to 1, and because the UE 802 has changed to the connected state, a state transition of the UE 802 is not necessary. Thus, the ProSa protocol 804 decides to send a trigger to the RRC layer 808.

[0091] In greater detail, as a result of failing to obtain a TxOP time, the ProSa 804 protocol checks the two aforementioned indicators established by the RRC layer 808. When the RRC layer 808 indicates that LTE-D is supported, but it is required an action (e.g., the discovery supported indicator and the trigger required indicator are set to 1), the ProSa protocol 804 checks to determine whether the UE 802 is in the connected state or the idle state. Because the ProSa 804 Protocol does not need to know what the SIB indicates as available resources (e.g. Type 1 Resources or Type 2 Resources), this information does not need to be communicated to the ProSa 804 Protocol (e.g. RRC 808 Layer Indicators) . That is, after a failed attempt to obtain a TxOP time, the ProSa Protocol 804 only needs to know that the required trigger indicator is set to 1 to know that it must determine the state of the UE 802 (e.g., connected state or idle state). ). In the present case, because the UE 802 is in the connected state (e.g., the NAS layer 806 of the UE 802 is in the connected state), no state transition is necessary, and the ProSa Protocol 804 tells the RRC layer 808 to send a resource request (e.g., an RRC D2D resource request) to the eNB 812.

[0092] Upon receiving the trigger (e.g., a trigger for D2D request) from the ProSa Protocol 804, the RRC layer 808 sends the request (e.g., RRC D2D resource request) to the eNB 812. Then, the eNB 812 respond to the RRC layer 808 by responding to the request, sending a response (e.g., RRC D2D resource response) back to the RRC layer 808. Thus, using the described D2D RRC message exchange, the eNB 812 is able to better schedule the network traffic (e.g., traffic involving the object UE 802 and other different UEs using the same eNB 812 to connect to the network).

[0093] Next, the RRC layer 808 configures the D2D MAC radio resources at the MAC layer 810 in accordance with the information contained in the response received from the eNB 812. That is, the D2D to D2D MAC radio resources are defined accordingly with the information obtained as a result of exchanging messages between the RRC layer 808 and the eNB 812. Then, the MAC layer 810 is capable of providing the ProSa protocol 804, with a time for TxOP D2D transmission.

[0094] In a similar way to the previously described case, also shown in Figure 9, once the ProSa Protocol 804 successfully obtains the TxOP time, the ProSa Protocol 804 calculates a MIC and subsequently sends a command to the MAC layer 810 corresponding to the subject ProSa application code and the calculated MIC, and according to the obtained TxOP Time. After that, the MAC layer 810 starts a D2D transmission according to the received command.

[0095] Figure 10 is a second diagram 1000 illustrating exemplary message exchange between the UE layers and an eNB. Referring below to figure 10, the above-mentioned case lc is discussed. In the present case, the UE 802 changes from an inactive state to a connected state. Again, the eNB 812's network supports LTE-D, and the SIB indicates that type 1 capabilities are available.

[0096] Accordingly, the RRC layer 808 sets the D2D radio resources at the MAC layer 810 to NULL. That is, the MAC D2D radio resources are removed from the MAC layer 810 by the RRC layer 808, so that it can subsequently define the MAC D2D radio resources according to the information contained in the previously described RRC message exchange between the RRC layer 808 and the eNB 812. Additionally, the RRC layer 808 establishes the supported discovery indicator and the required trigger indicator, which is information that can be seen by the ProSa Protocol 804.

[0097] In the present case, the ProSa Protocol 804 calculates a MIC based on an obtained ProSa application code, and sends a command to the MAC layer 810, in accordance with the ProSa application code and the calculated MIC, as the Protocol ProSa 804 is unaware that the RRC layer 808 has removed the MAC radio capabilities from the MAC layer 810. Unlike the case there, the command sent by the ProSa protocol 804 is received in error by the MAC layer 810, as the MAC layer 810 had Its RRC radio capabilities were previously removed by the RRC 808 layer, and it has not been reconfigured.

[0098] Thus, in the present case, the MAC layer 810, either sends an error notification back to the ProSa Protocol 804 to inform the ProSa Protocol 804 that there are no D2D radio resources available to the MAC layer 810, or, alternatively , the ProSa Protocol 804 simply fails in its attempt to obtain a TxOP time from the MAC layer 810 (for example, if a design choice removes the ability for the MAC layer 810 to send an error warning to the ProSa Protocol 804).

[0099] Upon receiving error notification from the MAC layer 810 (or failure to obtain a TxOP time), the ProSa Protocol 804 determines whether the UE 802 is in the connected state or in the idle state, so that the ProSa protocol 804 may decide whether to send a trigger to the RRC layer 808 (e.g., Fig. 9, case lb), or whether to initiate a state transition of the UE 802 from an idle state to a connected state (e.g. example, case 2a, described further with respect to figure 11).

[00100] In the present case, the ProSa Protocol 804 recognizes that the UE 802 is in the inactive state, upon communication with the NAS layer 806. As the NAS layer 806 of the UE is in the inactive state, the ProSa protocol 804 attempts to cause a transition of state of the UE 802 using what is referred to as a “legacy message”, or “service request”. When using the legacy/service request message, the ProSa Protocol 804 communicates with the NAS layer 806, and the NAS layer 806 switches the UE 802 to the connected state (ECM_CONNECTED), and indicates to the ProSa Protocol 804 that the state transition occurred.

[00101] Next, and in a manner similar to case lb, which is shown in Figure 9, the ProSe Protocol 804 sends a trigger for D2D Request to the RRC layer 808, thereby instructing the RRC layer 808 to recover network resources through the eNB 812. Upon receiving the trigger, the RRC layer 808 sends the request message (e.g., RRC D2D resource request message) to the eNB 812, and the eNB 812 responds by sending a response message (e.g., RRC D2D resource response) to the RRC layer 808. The RRC layer 808 then configures the D2D MAC radio resources at the MAC layer 810 according to the information contained in the response received from the eNB 812, thereby enabling the ProSa protocol 804 to successfully obtain a TxOP time from the MAC layer 810. Once the ProSa protocol 804 successfully obtains the TxOP time, the ProSa Protocol 804 calculates a MIC, and then sends a command to the MAC layer 810 corresponding to the subject application code ProSa and MIC, and according to the TxOP time obtained. After that, the MAC layer 810 starts a transmission according to the received command.

[00102] Figure 11 is a third diagram 1100 illustrating exemplary message exchange between UE layers and an eNB. With reference to figure 11, the aforementioned case 2a is discussed. In the present case, the UE 802 is an inactive state. Unlike the previously described scenarios according to exemplary embodiments, the SIB does not indicate that the type 1 resource is available, but instead only indicates that D2D communication is supported by the network (e.g., the network supports LTE-D). .

[00103] Therefore, as the SIB does not provide information regarding the specific type of resources available (e.g., whether type 1 or type 2), the D2D MAC radio resources are removed from the MAC layer 810 by the RRC layer 808 and the RRC 808 layer sets both the supported Discovery indicator (for example, the D2D Communications supported indicator) and the required trigger indicator, which is information that is seen by the ProSa 804 Protocol. How both indicators are defined, and as the UE 802 is in an inactive state, the UE 802 will transition states to become a connected state.

[00104] Again, the ProSa Protocol 804 calculates a MIC based on a obtained ProSa application code, and sends a command to the MAC layer 810 in accordance with the ProSa application code and calculated MIC. However, the ProSa protocol 804 fails in its attempt to obtain a TxOP time from the MAC layer 810, as the MAC layer 810 has had its D2D radio resources previously removed by the RRC layer 808. Failing to obtain a TxOP time , the ProSa protocol 804 communicates with the NAS layer 806 which indicates to the ProSa protocol 804 that the UE 802 is in an inactive state.

[00105] Once the UE 802 is in an idle state, the ProSa Protocol 804 sends a trigger to the NAS layer 806 so that the NAS layer 806 sends a service request (RS) (e.g., a service request with originating type calls) to the RRC layer 808 (for example, through the interaction channel 822 'shown in Figure 8). Then, the NAS layer 806 sends the service request to the RRC layer 808, and the RRC layer 808 communicates with the MAC layer 810, and also communicates with the network through the eNB 812 according to the corresponding procedures for the service request. service.

[00106] Then, once the UE 802 is in a connected state, and the NAS layer 806 receives an indication that the UE 802 is connected, the NAS layer 806 communicates to the ProSa protocol 804 (e.g., via the channel 822 shown in FIG. 8) that the UE is in a connected state (ECM_CONNECTED). It should be noted that the interaction between the above ProSa protocol 804 and the NAS layer 806 may occur when the UE 802 loses its connection after being in a connected state (e.g., case 2c in Figure 11).

[00107] Next, and in a similar manner to the scenarios discussed with respect to Figures 9 and 10 (e.g., cases lb and lc), the ProSa Protocol 804 sends a D2D trigger request to the RRC layer 808, causing The RRC layer 808 sends the request to the eNB 812, which then responds to the request by sending back a response. Then, the RRC layer 808 configures the D2D MAC radio resources at the MAC layer 810 according to the information contained in the response, and the ProSa Protocol 804 successfully obtains TxOP once from the MAC layer 810.

[00108] In the present case, the ProSa Protocol 804 probes the MAC layer 810 about the TxOP time to allow the ProSa Protocol 804 to understand when it can send the ProSa Code over the air. Once the ProSa Protocol 804 successfully obtains the TxOP Time, the ProSa Protocol 804 calculates a MIC, and sends a command to the MAC layer 810 corresponding to the subject ProSa application code and MIC, and in accordance with the obtained TxOP Time. After that, the MAC layer 810 starts a transmission according to the received command.

[00109] Figure 12 is a diagram 1200 illustrating exemplary message exchange between UE layers and an eNB. With reference to figure 12, the above-mentioned case 2b is discussed. In a similar manner to that shown in Figure 11 (e.g. case 2a), the SIB does not indicate which type 1 resources are available, but instead only indicates that D2D communication is supported by the network (e.g. the network supports LTE -D). However, unlike the situation described in relation to the 2nd case, the UE 802 is in a connected state. Therefore, no state transition of the UE 802 will be necessary for the intended D2D communication.

[00110] Again, the radio MAC resources are removed from the MAC layer 810 by the RRC layer 808 and the RRC layer 808 establishes the supported discovery indicator and the required trigger indicator, which is information that is seen by the ProSa Protocol 804.

[00111] Again, the ProSa Protocol 804 calculates a MIC based on a obtained ProSa application code, sends a command to the MAC layer 810 in accordance with the ProSa application code and calculated MIC, and fails in its attempt After failing to obtain a TxOP time, the ProSa Protocol 804 checks the indicators set by the RRC layer 808. Because the required trigger indicator is set to 1, the ProSa Protocol 804 determines whether the UE 802 is in the connected state or in the idle state. The ProSa 804 protocol determines the state of the UE 802 by communicating with the NAS layer 806, which indicates that the UE 802 is in a connected state in the present scenario.

[00112] Since the UE 802 is in a connected state, and unlike the scenario described in relation to case 2a, the ProSa protocol 804 does not need to send a trigger to the NAS layer 806 to transfer the UE 802 from a idle state to connected state. Consequently, and in a similar manner to the scenarios discussed in relation to Figures 9, 10 and 11 (cases lb, lc and 2a), the ProSa Protocol 804 sends a trigger for requesting D2D resources to the RRC layer 808, the RRC layer 808 engages in a message exchange (e.g., a D2D RRC resource exchange request message) with the eNB 812. Next, the RRC layer 808 configures the D2D MAC radio resources at the MAC layer 810, according to information obtained from from the eNB 812 through the D2D resource request message exchange, and the ProSa Protocol 804 successfully obtains a TxOP time from the MAC layer 810. Then, the ProSa protocol 804 sends a command to the MAC layer 810 corresponding to the subject ProSa application code and the calculated MIC, and according to the TxOP time obtained, thus allowing the MAC layer 810 to initiate a transmission in accordance with the received command.

[00113] Figure 13 is a fifth diagram 1300 illustrating exemplary message exchange between UE layers and an eNB. Referring to figures 11 and 13, the aforementioned case 2c is discussed. Unlike the previously described embodiments, the system information/SIB indicates that D2D resources are allocated by the eNB 812. That is, instead of having a type 1 resource pool for the UE 802 to choose its resources from, type 2 resources are assigned, or assigned, to the UE 802, as determined by the network to which the eNB 812 is connected. That is, Type 2 indicates that the network informs the UE 802 specifically which resources to use, and provides the UE 802 with dedicated resources, as opposed to the UE 802 selecting resources from a pool of resources (e.g., type 1). Furthermore, the UE 802 is in a connected state.

[00114] Thus, in the present case, the ProSa protocol 804 obtains a successful TxOP time from the MAC layer 810, and the ProSa Protocol 804 sends a command to the MAC layer 810 corresponding to the ProSa application code and the calculated MIC , and according to the TxOP time obtained, thus allowing the MAC layer 810 to initiate a transmission according to the received command. However, in the present situation, before the MAC layer 810 successfully completes the intended D2D communication, the eNB 812 sends an RRC D2D Resources Revocation message to the RRC layer 808, as shown in Figure 13 (although the following description also applies when the UE 802 would somehow otherwise lose connection, as shown in figure 11).

[00115] Next, the RRC layer 808 indicates to the ProSa protocol 804 that both the supported Discoverable indicator and the required trigger indicator are defined, and the RRC layer 808 removes the MAC D2D radio resources from the MAC layer 810. Thus, when The ProSa Protocol 804 sends a command to the MAC layer 810, according to the ProSa application code and calculated MIC, the ProSa Protocol 804 fails in its attempt to obtain a TxOP time from the MAC layer 810. Then the ProSa Protocol 804 communicates with the NAS layer 806, which indicates that the UE 802 is still in a connected state, and consequently, a state transition is not required, and the ProSa protocol 804 does not need to send a trigger for an SR service request for the NAS layer 806 (as was the case in the scenario described with respect to case 2a).

[00116] Again, and in a similar way to the scenarios discussed in relation to figures 9, 10, 11, and 12 (cases lb, lc, 2a, and 2b), because the NAS layer 806 indicates that the UE 802 is in a connected state, the ProSa Protocol 804 sends a D2D request trigger to the RRC layer 808, the RRC layer 808 engages in an RRC D2D resource message exchange with the eNB 812, and configures the D2D MAC radio resource on the MAC layer 810 in accordance with the RRC D2D resource message exchange. Then, the ProSa protocol 804 successfully obtains a TxOP time from the MAC layer 810, sends a command to the MAC layer 810 corresponding to the subject ProSa application code and the MIC calculated according to the obtained TxOP Time, allowing as soon as the MAC layer 810 initiates a transmission in accordance with the received command.

[00117] According to other cases that may be experienced by exemplary embodiments, when an error occurs, either in the RRC layer 808 receiving a response to its request for RRC D2D resources from the eNB 812, or in the configuration of the RRC layer 808 of the RRC D2D resources D2D MAC radio, the ProSa Protocol 804 will resend the trigger for D2D request to the RRC layer 808 after a timeout occurs. That is, after a certain period of time has elapsed following the initial sending of the trigger to the RRC layer 808 of the ProSa Protocol 804, when the ProSa Protocol 804 does not receive communication from the MAC layer 810, the ProSa Protocol 804 resends the D2D request to the RRC layer 808 to restart a portion of the process described above.

[00118] Finally, in an alternative case (e.g., case 3, not shown), the RRC layer 808 may indicate to the ProSa Protocol 804 that the supported discovery indicator is not set (e.g., that the network connected to the station server base/eNB 812 does not support peer discovery). In such a scenario, the ProSa 804 Protocol should not attempt D2D operations.

[00119] Also considered as potential cases by exemplary embodiments are situations in which the ProSa 804 protocol aims to provide multiple ProSa application codes. The ProSa Protocol 804 can have multiple ProSa application codes to be announced over the air. When the ProSa protocol 804 has multiple ProSa application codes to send, the ProSa protocol 804 requests and obtains multiple TXOP times from the MAC layer 810 through the interaction channel 823. Since the resources for D2D transmission are distributed in both frequency and domain of time, it is possible that the resources for the multiple TXOP possibilities correspond to different absolute time values. For example, when the ProSa protocol 804 requests two transmission opportunities, the MAC layer 810 may return a time t and a time t + 1 second. These times may be based on the selection of the Type 1 resource pool, or based on a resource allocation as determined by eNB 812.

[00120] Thus, in the current scenario, the ProSa Protocol 804 calculates an individual MIC for each of the ProSa application codes based on the different times. For example, a first MIC for application code ProSa 1 is calculated as time t, and a second MIC for application code ProSa 2 is calculated as time t+1.

[00121] In this way, to ensure that the transmission times t and t+1 for the different messages coincide with their respective MIC, which thus ensures that a receiving UE (to which the UE 802 intends to deliver the messages) can correctly validate the messages, when the ProSa Protocol 804 sends the ProSa application code and MIC to the MAC layer 810 for transmission, the ProSa Protocol 804 informs the MAC layer 810 which ProSa application code should be transmitted at what time. Exemplary embodiments provide two approaches for indicating the possibility of transmission between the MAC layer 810 and the ProSa protocol 804. That is, two possible approaches for indicating the TXOP opportunity transmission times between the MAC layer and the 810 ProSa protocol 804 are provided below. Prose.

[00122] In the first approach, an indexing system uses separate index numbers assigned to respective TXOP times to distinguish different TXOP times. For example, when the ProSa protocol 804 requests multiple TxOPs, the MAC layer 810 will index each of these TXOP times with an index number.

[00123] When the ProSa Protocol 804 sends (e.g., through the lower layers) one of the ProSa application codes and the corresponding MIC toward MAC layer 810, the ProSa Protocol 804 may indicate the index number corresponding to the particular TxOP time used. for calculating the private MIC. In the present embodiment, the MAC layer 810 provides the TXOP times in a sequence, and the ProSa protocol 804 can send the various ProSa protocol codes and corresponding MICs according to the same sequence as the time used for the respective MIC calculations. When the MAC layer 810 responds to the ProSa protocol 804, the MAC layer 810 includes a corresponding time value for each of the TXOP times provided, even though some of the time values may be identical.

[00124] In a second alternative approach, the ProSa Protocol 804 sends the ProSa application code and MIC along with the TxOP time used for the MIC calculation when the ProSa Protocol 804 transmits the ProSa application code. Accordingly, the ProSa Protocol 804 may send a TxOP request to request multiple TXOP opportunities, one for each of the ProSa application codes. Next, the ProSa Protocol 804 indicates in the TxOP request sent to the MAC layer 810 the number of ProSa application codes to be transmitted. The MAC layer 810 may respond with a list of TXOP times in accordance with the request received from the ProSa protocol layer 804. The MAC 810 of the present embodiment may respond with an individual index number for each TxOP time, or it may send a sequence implying the index for all TXOP times, in which case the MAC layer 810 memorizes the mapping between the various index numbers and their corresponding TxOP time. However, the ProSa Protocol 804 may include the TxOP time when sending the command to the ProSa application code transmission, thus eliminating any need for the MAC layer 810 to remember index number mapping.

[00125] Additionally, in an alternative operation, the ProSa Protocol 804 can use multiple requests when it has multiple codes to send, instead of sending a single TxOP request indicating multiple requested TXOP times. In such an alternative operation, the ProSa Protocol 804 would indicate in the request whether the TxOP is a new code, or whether the ProSa Protocol 804 is requesting a new TxOP for an existing previous request/ProSa Code. For example, the ProSa 804 protocol can index the ProSa application code with an index number, and include it in the request. This way, the MAC layer knows whether the request is for a new ProSa application code, although the MAC layer can remember the index mapping and the corresponding TXOP resources assigned to it.

[00126] The RRC layer 808 may encounter a situation where the available radio resources have changed. For example, in the Type 2 resource allocation case (e.g., Fig. 13, case 2c), the eNB 812 may decide to add or reduce the resources allocated to the UE 802 based on the eNB's load 812, or based on the number of UEs requesting for D2D transmission. When the available radio resources have changed, the RRC layer 808 can inform the ProSa protocol 804 to act accordingly.

[00127] For example, the RRC layer 808 may send an indication (that available radio resources have changed) toward the ProSa Protocol 804 with a system-level indicator (e.g., a “resource updated” indicator). This will trigger the ProSa Protocol 804 to either request more TXOP times from the MAC layer 810, or send the trigger to the RRC layer 808 for resource allocation, along with another indication of the extent of the resources are needed. The RRC layer 808 can respond with the actual resources allocated by the network.

[00128] In an alternative embodiment, when the RRC layer 808 encounters a situation where the available radio resources have changed, the RRC layer 808 can simply configure the MAC layer 810 with the updated resources. Thus, when the ProSa Protocol 804 requests the TxOP time at the next opportunity to communicate with the MAC layer 810, the ProSa Protocol will notice the change in network resources (e.g., the ProSa Protocol may see only two TXOP values although it requested three of the MAC layer 810). In this case, the ProSa 804 protocol will decide the corresponding operation (for example, suspending the transmission of one or more of the ProSa Application Codes according to a set of priorities, or alternating the transmission of the three codes with the two possible TXOP opportunities).

[00129] It should be noted that, although the previous description of the described cases addresses the UE 802 as a transmitting UE 802 (e.g., a UE advertising on LTE-D), the above description may also be applicable to a receiving UE ( for example, the other UE, or a monitoring UE). In this case, the monitoring UE is in a connected state, or when the network indicates that there are no resources in the SIB, the RRC layer 808 can set the required trigger indicator (e.g., set the value to 1). When the ProSa protocol 804 decides that it wants to receive the ProSa application code, it will trigger the RRC layer 808 to send the RRC D2D Resource Request message to the eNB 812. When the eNB 812 responds with the corresponding confirmation, the layer RRC 808 may define the MAC layer 810 accordingly to receive the D2D resources.

[00130] In the present case, the RRC D2D resource request is no longer for D2D transmit resources, but instead is used to indicate to the eNB 812 that the UE would perform D2D operation on the receive resources, so that the eNB 812 must avoid scheduling any normal LTE communications over these resources, thus potentially avoiding negative impact to other UE applications. Therefore, the D2D Resource response message sent to the RRC layer 808 back from the eNB 812 does not have to include resource information, but may instead simply include an acknowledgment.

[00131] In another alternative case, the advertising UE may be a monitoring UE as well, in which the same operation applies. In such a case, the RRC D2D resource request message sent to the eNB 812 would indicate whether the corresponding message is for transmitting resources, for receiving programming assistance, or for both. The RRC D2D resource response message sent back from the eNB 812 includes transmit resources when the message corresponds to transmit resources, or both transmit resources and receive programming assistance.

[00132] In another alternative case, the monitoring UE may indicate to the RRC layer 808 that it only wishes to receive for a specific public land mobile network (PLMN) or a specific country code. In this case, the RRC layer 808 may translate this request, and may indicate that desire in the corresponding RRC D2D Resource Request. In the RRC D2D Resources response, the eNB 812 may instruct the UE 802 to operate in a certain way to perform the monitoring action (for example, it may instruct the UE 802 to leave gap for frequency re-adjustment in a certain period of time) .

[00133] Figure 14 is a flowchart 1400 of a wireless communication method. The method may be performed by a UE (e.g. the UE 802).

[00134] In step 1402, a ProSa Protocol (e.g., ProSa Protocol 804) obtains a ProSa application code. In step 1404, an RRC layer (e.g., RRC layer 808) obtains system information (e.g., the SIB). In step 1406, the RRC layer determines whether system information indicates that the network (e.g., the eNB network 812) supports peer discovery (e.g., whether the network is an LTE-D network). If the system information indicates that the network does not support D2D communication, then the RRC layer disables an indicator (for example, a second indicator or supported discovery indicator) such that a value corresponding to them is 0. in step 1408. Therefore, the ProSa Protocol should not attempt D2D communication, and the process is terminated.

[00135] If the system information indicates that the network supports peer discovery, or supports D2D communication, then the RRC layer sets the indicator (for example, the discovery supported indicator or D2D communication supported indicator), such that a corresponding value is one, in step 1410. In step 1412, the RRC layer determines whether the system information indicates Type 1 Resources, and in step 1414, the RRC layer determines whether the UE is in a state inactive. If the RRC layer determines at steps 1412 and 1414 either that the failed system information indicates resource type 1, or that the UE is not in an idle state (for example, the UE is in a connected state), then the RRC layer defines another indicator (e.g., a first indicator, or the required trigger indicator) in step 1416, and then removes the D2D radio resources from a MAC layer (e.g., the MAC layer 810) in step 1418.

[00136] However, if the RRC layer determines that the system information indicates resource type 1, and that the UE is in the idle state, the RRC layer will remove the other indicator (e.g., set the required trigger indicator to 0 ) in step 1420, and will configure the MAC layer D2D radio resources in step 1422.

[00137] After the RRC layer configures the MAC layer D2D radio resources in step 1422, or removes the MAC layer D2D radio resources in step 1418, the ProSa Protocol will attempt to obtain a TxOP time from the MAC layer in step 1424. It should It will be noted that several ProSa application codes can be obtained within the scope of Figure 14, in which case, several corresponding MICs will be calculated, and several TXOP times can be obtained from the MAC layer, as discussed above.

[00138] If the ProSa Protocol attempt is successful, in step 1426, the ProSa Protocol calculates a message consistency integrity (MIC) for the application code in ProSa, which was obtained in step 1402, and sends the MIC and the ProSa application code to the MAC layer.

[00139] However, if the ProSa Protocol's attempt to obtain the TxOP time from the MAC layer at step 1424 is unsuccessful, then at step 1428, the ProSa Protocol checks the indicators defined by the RRC layer (e.g., to verify that the required trigger indicator is set and/or to check the Supported Discovery indicator is set).

[00140] If, after sending the MIC and ProSa Application Code to the MAC layer in step 1426, an error notification is received by the ProSa Protocol from the MAC layer in step 1430, or after verifying that the required trigger indicator is set at 1428, the ProSa protocol checks with the NAS layer to determine whether the UE is in the connected state in step 1432.

[00141] If the UE is determined not to be in a connected state in step 1432, then in step 1434, the ProSa Protocol sends a service request to trigger the NAS layer to switch to a connected state. Then, in step 1436, the UE is transferred to a connected state. Then, in step 1438, the NAS layer indicates to the ProSa protocol that the RRC is in a connected state.

[00142] After step 1438, or alternatively, if the UE is determined to be in a connected state at step 1432, the ProSa protocol layer instructs the RRC layer to send a resource request to a serving base station (e.g. , the eNB 812 ) in step 1440. In step 1442, the RRC layer requests resource allocation from the serving base station. In step 1444, the serving base station sends a response to the D2D layer allocating RRC resources, such as peer discovery resources or D2D communication resources. After that, the RRC layer returns to step 1422, and configures the MAC layer radio resources.

[00143] However, if no error notification is received by the MAC layer ProSa Protocol at step 1430, if radio resources are not revoked by the eNB at step 1446, and if D2D communication has not been terminated at step 1448, then , the UE may return to step 1402 to obtain additional ProSa Application codes for new transmissions.

[00144] Alternatively, if resources are revoked, the RRC layer returns to step 1416 to set the required trigger indicator. If D2D communication is terminated at step 1448, then the process ends.

[00145] Figure 15 is a diagram 1500 illustrating a first wireless communication method. The method may be performed by a UE, such as UE 802. At 1502, the UE determines whether the information received from the communication system is D2D. A first layer of the UE may receive system information and configure the at least one indicator, and a second layer that is higher than the first layer may check the at least one indicator and request the first layer to determine D2D resources (e.g., spy on discovery resources).

[00146] At 1504, in one configuration, when system information is determined to have been received for D2D communication, the UE may determine whether a set of D2D resources (e.g., common pair of discovery resources) is indicated in the system information. At 1506, the UE may determine a radio resource control (RRC) state of the UE.

[00147] At 1508, in one configuration, when system information is determined to have been received for D2D communication, and when a set of D2D resources, such as a set of peer common discovery resources, is indicated in the system information system, the UE can perform D2D communication, such as D2D peer discovery communication, using the D2D resource set. At 1510 the UE may stop D2D communication via the D2D resource pool. At 1512, the UE may transition from an RRC idle state to an RRC connected state.

[00148] At 1514, in one configuration, when system information is determined to have been received for D2D communication, and when a set of D2D resources, such as a set of peer common discovery resources, is not indicated in the information system, the UE can perform D2D communication such as D2D point discovery communication through an allocated set of resources. At 1516, the UE may receive a revocation of the use of the allocated pool of resources.

[00149] At 1518, the UE defines at least one indicator based on system information when system information is received. The indicator, at least one, can be adjusted based on whether the set of D2D resources is indicated in the system information, and based on the determined RRC state. When the D2D resource pool is determined to be indicated in system information and when the RRC state is determined to be an RRC inactive state, and defining the at least one indicator may include establishing a first indicator of the at least one indicator for indicate to the second layer that a request for allocation of D2D resources is without consideration. When the D2D resource set is determined to be indicated in the system information and when the RRC state is determined to be an RRC connected state, defining the at least one indicator may include establishing a first indicator of the at least one indicator to indicate that a D2D allocation request is required. When the D2D resource set is determined not to be indicated in the system information, and when the RRC state is determined to be an RRC inactive state, configuring the at least one indicator may include establishing a first indicator of, at least least, an indicator to indicate to the second layer that a request for allocation of D2D resources is necessary. When the D2D resource set is determined not to be indicated in the system information, and when the RRC state is determined to be an RRC connected state, defining the at least one indicator may include establishing a first indicator. at least one indicator to indicate to the second layer that a D2D resource allocation request is necessary. The at least one indicator may be set upon transition from the RRC idle state to the RRC connected state. Defining the at least one indicator may include establishing a first indicator of the at least one indicator to indicate that a request is required for the allocation of D2D resources. When system information is determined to have not been received for D2D communication, and by defining the at least one indicator includes defining an indicator of the at least one indicator indicating that D2D communication is not supported, the D2D resources can be determined as being a null set. At 1520, the UE determines D2D capabilities based on at least one indicator.

[00150] In one configuration, the first layer is an RRC layer, and the second layer is a ProSa protocol layer. For cases la, lb, 2a, 2b, in one configuration, system information is determined to have been received for D2D communication (1502), and the UE determines whether a set of D2D resources, such as a set of common discovery peers, is indicated in the system information (1504), and determines an RRC state of the UE (1506). In such a configuration, the indicator of at least one is defined based on whether the set of D2D resources is indicated in the system information, and based on the determined state RRC (1518).

[00151] In one configuration, for case la, the set of D2D resources (e.g., common discovery resource pairs) is determined to be indicated in the information system (1504), and the RRC state is determined to be a inactive state RRC ( 1506). Furthermore, the first layer sets the at least one indicator by defining a first indicator of the at least one indicator to indicate to the second layer that a D2D resource allocation request is unmatched (1518). In one embodiment, the first layer sets the at least one indicator, setting a second indicator of the at least one indicator to indicate that D2D communication is supported (1518). In one configuration, the UE determines from at least one indicator that D2D communication is supported, and that a D2D resource allocation request is unrequited. In such a configuration, the UE determines the D2D resources by determining to use the set of D2D resources indicated in the system information for D2D communication (1520).

[00152] In one configuration, for the case lb, the set of D2D resources (e.g., common pair discovery resources) is determined to be indicated in the system information (1504), and the RRC state is determined to be a RRC connected state (1506). In such a configuration, the first layer sets the at least one indicator, defining a first indicator of the at least one indicator to indicate that a D2D resource allocation request (1518) is required. In one embodiment, the first layer sets the at least one indicator, setting a second indicator of the at least one indicator to indicate that D2D communication is supported (1518). In one configuration, the UE determines from at least one indicator that D2D communication is supported, and that a D2D resource allocation request is required. In such a configuration, the UE determines the D2D resources upon request, in the second layer, the first layer requests an allocation of D2D resources from a serving base station; and receiving the allocation of D2D resources from the serving base station (1520). In such a configuration, D2D resources are determined by the received D2D allocated resources. In one configuration, the UE determines from at least one indicator that D2D communication is supported, and that a D2D resource allocation request is required. In such a configuration, the UE determines the D2D resources upon request, in the second layer, the first layer of requiring to perform D2D communication with a set of D2D resources from a serving base station; and by receiving a confirmation from the base station that the D2D resource pool is reserved for D2D communication (e.g., peer discovery) (1520).

[00153] In one configuration, in case 2a, the set of D2D resources (e.g., common pair discovery resources) is determined to not be indicated in the system information (1504), and the RRC state is determined to be a idle state RRC (1506). In such a configuration, the first layer sets the at least one indicator, setting a first indicator of the at least one indicator to indicate that a D2D resource allocation request (1518) is required from the second layer. In one embodiment, the first layer sets the at least one indicator, setting a second indicator of the at least one indicator to indicate that D2D communication is supported (1518). In one configuration, the UE determines from at least one indicator that D2D communication is supported, and that a D2D resource allocation request is required. In such a configuration, the UE determines D2D resources by transitioning from the RRC idle state to an RRC connected state upon request, in the second layer, the first layer requests an allocation of D2D resources from a serving base station, and for receiving the allocation of D2D resources from the serving base station (1520). In such a configuration, D2D resources are determined by the received D2D allocated resources. In one configuration, the UE controls, by the second layer, a third layer that is higher than the first layer to cause the first layer to transition from the RRC idle state to the RRC connected state. In one configuration, the third layer is a NAS layer.

[00154] In one configuration, in case 2b, the set of D2D resources (e.g., common pair of discovery resources) is determined to be not indicated in the system information (1504), and the RRC state is determined to be a RRC connected state (1506). In such a configuration, the first layer sets at least one indicator, defining a first indicator of the at least one indicator to indicate to the second layer that a D2D resource allocation request (1518) is required. In one embodiment, the first layer sets the at least one indicator, setting a second indicator of the at least one indicator to indicate that D2D communication is supported (1518). In one configuration, the UE determines from at least one indicator that D2D communication is supported, and that a D2D resource allocation request is required. In such a configuration, the UE determines D2D resources upon request, in the second layer, the first layer requests an allocation of D2D resources from a serving base station, and upon receipt of the allocation of D2D resources from the serving base station , where the determined D2D resources are the received D2D allocated resources (1520). In one configuration, the UE determines from at least one indicator that D2D communication is supported, and that a D2D resource allocation request is required. In such a configuration, the UE determines the D2D resources upon request, in the second layer, the first layer of requesting to perform D2D communication with a set of D2D resources of a serving base station, and by receiving an acknowledgment from the base station that the D2D resource pool is reserved for D2D communication (e.g., peer discovery) (1520).

[00155] In one configuration, in case lc, system information is determined to have been received for D2D communication (1502), and the set of D2D resources (e.g., common pair of discovery resources) is indicated in the system of information (1504). In such a configuration, the UE performs D2D communication using the D2D resource set (1508), stops D2D communication via the D2D resource set (1510), and transitions from an RRC idle state to an RRC connected state (1512). . Furthermore, in such a configuration, the at least one indicator is placed on the transition from the RRC idle state to the RRC connected state, and the first layer adjusts the at least one indicator by defining a first indicator. o at least one indicator to indicate that a request is required for the allocation of D2D resources (1518). In one embodiment, the first layer sets the at least one indicator, setting a second indicator of the at least one indicator to indicate that D2D communication is supported (1518). In one configuration, the UE determines from at least one indicator that D2D communication is supported, and that a D2D resource allocation request is required. In such a configuration, the UE determines the D2D resources by determining, in the second layer, that no D2D resources are available; upon request, in the second layer, the first layer requests an allocation of D2D resources from a serving base station, and upon receiving the allocation of D2D resources from the serving base station (1520). In such a configuration, the determined D2D resources are the received allocated D2D resources.

[00156] In one configuration, in case 2c, the system information is determined to have been received for D2D communication (1502), and the D2D resource set is not indicated in the system information (1504). In such a configuration, the UE performs D2D communication using an allocated set of D2D resources (e.g., an allocated set of peer discovery resources) (1514), and receives a revocation of use of the allocated set of D2D resources (1516). . In such a configuration, the first layer sets at least one indicator, defining a first indicator of the at least one indicator to indicate that a request is required for the allocation of D2D resources (1518). In one embodiment, the first layer sets the at least one indicator, setting a second indicator of the at least one indicator to indicate that D2D communication is supported (1518). In one configuration, the UE determines from at least one indicator that D2D communication is supported, and that a D2D resource allocation request is required. In such a configuration, the UE determines the D2D resources by determining, in the second layer, that there are no D2D resources available; upon request, in the second layer, that the first layer requests an allocation of D2D resources from a serving base station, and upon receipt of the allocation of D2D resources from the serving base station, wherein the determined D2D resources are the D2D assigned received resources (1520).

[00157] In one configuration, in case 3, system information is not determined to have been received for D2D communication (1502), and the first layer sets the at least one indicator, setting an indicator of the at least one indicator indicating that D2D communication is not supported, where D2D resources are determined to be a null set (1518). In one configuration, the UE transmits signals on D2D resources (e.g., peer discovery resources).

[00158] Figure 16 is a conceptual data flow diagram 1600 illustrating the data flow between different modules/medium/components of an exemplary apparatus 1602. The apparatus 1602 may be a UE. Apparatus 1602 includes a receiving module 1610 that is configured to receive system information for D2D communication. The apparatus 1602 further includes an information system determination module 1612 that is configured to determine whether the information received from the communication system is D2D. The apparatus 1602 further includes an indicator configuration module 1614 that is configured to define at least one indicator based on system information when system information is received (e.g., information corresponding to resource discovery pairs allocated by a base station 1640). Apparatus 1602 further includes a D2D resource determination module (e.g., a peer discovery resource determination module) 1616 that is configured to determine D2D resources based on at least one indicator. In one configuration, a first layer of the apparatus 1602 comprises the reception module 1610, the indicator configuration module 1614, and the D2D resource determination module 1616, and a second layer of the apparatus 1602 that is larger than the first layer is configured to check at least one indicator and to request the first layer to determine D2D capabilities. In one embodiment, the apparatus 1602 further includes an RRC control and state determination module 1618 that is configured to determine an RRC state of the apparatus 1602, while the system information determination module 1612 is configured to determine whether a set of of D2D resources is indicated in the system information, and at the same time the indicator configuration module 1614 is configured to define at least one indicator based on whether the set of D2D resources is indicated in the system information, and based on in the given RRC state. In one configuration, when the D2D resource set is determined to be indicated in the system information and when the RRC state is determined to be an RRC inactive state, the indicator configuration module 1614 is configured to set the first indicator of at least an indicator to indicate to the second layer that a request for allocation of D2D resources is without consideration. In one configuration, when the D2D resource set is determined to be indicated in system information and when the RRC state is determined to be an RRC connected state, the indicator configuration module 1614 is configured to set the first indicator of at least an indicator to indicate that a request for allocation of D2D resources is required. In one configuration, when the D2D resource set is determined to not be indicated in the system information, and when the RRC state is determined to be an RRC inactive state, the indicator configuration module 1614 is configured to define a first indicator of at least one indicator to indicate to the second layer that a request for allocation of D2D resources is required. In one configuration, when the D2D resource set is determined not to be indicated in the system information, and when the RRC state is determined to be an RRC connected state, the indicator configuration module 1614 is configured to define a first indicator of at least one indicator to indicate to the second layer that a request for allocation of D2D resources is required. In one embodiment, the apparatus 1602 further includes a transmission module 1620, and when system information is determined to have been received for D2D communication, and when a set of D2D resources is indicated in the system information, the transmission module 1620 is configured to perform D2D communication (e.g., with another UE 1650) using the D2D resource set, and is configured to stop D2D communication through the D2D resource set, while the state determination and control module RRC 1618 is configured for transitioning the apparatus 1602 from an RRC inactive state to an RRC connected state, and at the same time the indicator configuration module 1614 is configured to define the at least one indicator upon the apparatus 1602 transitioning from the inactive state RRC for the RRC connected state, and is configured to define a first indicator of o at least one indicator to indicate that a request is required for the allocation of D2D resources. In one configuration, when system information is determined to have been received for D2D communication, and when a set of D2D resources is not indicated in the system information, the transmission module of 1620 is configured to perform D2D communication, as D2D peer discovery communication, using an allocated set of D2D resources, and the receiving module 1610 is configured to receive a revocation of the use of the allocated set of D2D resources, and the indicator configuration module 1614 is configured to define a first indicator o at least one indicator to indicate that a request is required for the allocation of D2D resources.

[00159] Figure 17 is a diagram 1700 illustrating an example of a hardware implementation for an apparatus 1602' employing a processing system 1713. The processing system 1713 can be implemented with a bus architecture, generally represented by bus 1724 Bus 1724 may include any number of interconnect buses and bridges, depending on the specific application of the 1713 processing system and overall design constraints. Bus 1724 connects various circuits, including one or more processors and/or hardware modules, represented by processor 1704, modules 1610, 1612, 1614, and the media/memory optical readout computer 1706. Bus 1724 may also connect various other circuits, such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and, consequently, will not be described further.

[00160] The processing system 1713 may be coupled to a transceiver 1710. The transceiver 1710 is coupled to one or more antennas 1720. The transceiver 1710 provides a means for communicating with various other devices via a transmission medium. The transceiver 1710 receives a signal from the one or more antennas 1720, extracts information from the received signal, and provides the extracted information to the processing system 1713. Additionally, the transceiver 1710 receives information from the processing system 1713, and based on the information received, generates a signal as applied to one or more antennas 1720. The processing system 1713 includes a processor 1704 coupled to a computer readable medium/memory 1706. The processor 1704 is responsible for processing general, including the execution of software stored on the computer-readable medium/memory 1706. The software, when executed by the processor 1704, causes the processing system 1713 to perform the various functions described above for any particular apparatus. The computer readable medium/memory 1706 may also be used for storing data that is manipulated by the processor 1704 when executing software. The processing system further includes at least one of modules 1610, 1612, 1614. The modules may be software modules running on processor 1704, resident/stored on the computer readable medium/memory modules 1706, one or more hardware coupled to the 1704 processor, or some combination thereof. The processing system 1713 may be a component of the eNB 610 and may include memory 676 and/or at least one of the TX processor 616, the RX processor 670, and the controller/processor 675.

[00161] In one configuration, the apparatus 1602/1602' for wireless communication may be a UE. The UE comprises means for determining whether system information is received by device-to-device (D2D) communication, the means of fixing at least one indicator based on system information when system information is received, and means for determining D2D capabilities based on the at least one indicator.

[00162] The UE may further include means for determining whether a set of D2D resources is indicated in the system information, and means for determining a radio resource control (RRC) state of the UE. The indicator, at least one, can be adjusted based on whether the set of D2D resources is indicated in the system information, and based on the determined RRC state. The means for attaching at least one indicator may be configured to define a first indicator or at least one indicator to indicate to the second layer that a request for allocation of D2D resources is either necessary, or without consideration, depending on whether the D2D resource set is determined as being indicated in the system information and about determining the RRC state.

[00163] The UE may further include means for effecting D2D communication using a set of D2D resources, means for stopping D2D communication through the set of D2D resources, and means for transitioning from an RRC idle state to an RRC connected state. When system information is determined to have been received for D2D communication, and when the set of D2D resources is indicated in the system information, at least one indicator is set upon transition from the RRC idle state to the RRC connected state, and The means to set the indicator at least one is configured to set a first indicator of at least one indicator to indicate that an order is required for the allocation of D2D resources.

[00164] The UE may further include means for performing D2D communication using a D2D allocated resource pool, and means for receiving a revocation of the use of the D2D allocated resource pool. When system information is determined to have been received for D2D communication, and when the D2D resource set is not indicated in the system information, the means of setting the at least one indicator are configured to set a first indicator of the at least at least one indicator to indicate that a request is required for the allocation of D2D resources.

[00165] The aforementioned means may be one or more of the aforementioned modules of the apparatus 1602 and/or the processing system 1713 of the apparatus 1602' configured to perform the aforementioned functions by the aforementioned means. As described above, the processing system 1713 may include the TX processor 668, the RX processor 656, and the controller/processor 659. As such, in one embodiment, the aforementioned means may be the TX processor 668, the RX processor 656 , and the controller/processor 659 configured to perform the functions recited by the aforementioned means.

[00166] It is understood that the specific order or hierarchy of steps in the disclosed processes is an example of exemplary approaches. Based on design preferences, it is understood that the specific order or hierarchy of steps in the processes may be rearranged while remaining within the scope of the present disclosure. The accompanying method claims present elements of the various steps in an exemplary order, and are not intended to limit the specific order or hierarchy presented.

[00167] The foregoing description is provided to enable those skilled in the art to practice the various aspects described herein. Various modifications in these aspects will be readily apparent to those skilled in the art, and the generic principles defined here may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown here, but must be granted the broadest scope consistent with the language claims, in which reference to an element in the singular is not intended to mean “one and only one” unless which is specifically so stated, but more properly “one or more”. Unless specifically stated otherwise, the term “any” refers to one or more. The word “exemplary” is used here to mean “to serve as an example, case, or illustration.” Any aspect described herein as “exemplary” should not necessarily be construed as preferred or advantageous over other aspects. Unless specifically indicated otherwise, the term “one” refers to one or more. Combinations such as “at least one of A, B, or C,” “at least one of A, B, and C,” and “A, B, C, or any combination thereof include any combination of A, B, and/or C, and may include multiples of a, B, multiples of, or multiples of C. Specifically, combinations such as “at least one of a, B, or C”, “at least one of a, B, and C , “and” A, B, C, or any combination thereof may be a single, B only, C only, A and B, A and C, B and C, or A and B and C, where such combinations may contain one or more member or members of a, B, or C. All structural and functional equivalents to elements of the various aspects described throughout this disclosure, which are known or which later come to be known to those skilled in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Furthermore, nothing disclosed herein should be dedicated to the public regardless of whether such disclosure is explicitly cited in the claims. No claim element should be considered a means plus function unless the element is expressly cited using the phrase “means for”.

Claims (15)

1. Method (1500) of wireless communication of a user equipment, UE, characterized by the fact that it comprises: determining (1502) whether system information is received for device-to-device communication, D2D; configuring (1518) at least one indicator based on the system information when the system information is received, wherein a first protocol layer of the UE receives the system information and configures the at least one indicator; and determining (1520) D2D capabilities based on the at least one indicator, wherein a second protocol layer that is higher than the first protocol layer checks the at least one indicator and requests the first protocol layer to determine the D2D capabilities . 2. The method of claim 1, wherein the system information is determined to have been received for D2D communication, the method further comprising: determining whether a set of common D2D resources is indicated in the system information; and determining a radio resource control, RRC, state of the UE, wherein the at least one indicator is configured based on whether the set of common D2D resources is indicated in the system information and based on the determined RRC state. 3. The method of claim 2, wherein the set of common D2D resources is determined to be indicated in the system information, and the RRC state is determined to be an RRC idle state, and wherein configuring the at least one indicator comprises configuring a first indicator of the at least one indicator to indicate to the second layer that a request for an allocation of the D2D resources is not necessary. 4. The method of claim 2, wherein the set of common D2D resources is determined to be indicated in system information, and the state of RRC is determined to be a connected state of RRC, and wherein configuring the at least one indicator comprises configuring a first indicator of the at least one indicator to indicate that a request for an allocation of D2D resources is necessary. 5. The method of claim 2, wherein the set of common D2D resources is determined not to be indicated in the system information, and the RRC state is determined to be an RRC idle state, and in that configuring the at least one indicator comprises configuring a first indicator of the at least one indicator to indicate to the second protocol layer that a request for an allocation of D2D resources is necessary. 6. Method according to claim 2, characterized by the fact that the D2D resource set is determined not to be indicated in the system information, and the state of RRC is determined to be a connected state of RRC, and wherein configuring the at least one indicator comprises configuring a first indicator of the at least one indicator to indicate to the second layer that a request for an allocation of D2D resources is necessary. 7. The method of claim 1, wherein the system information is determined to have been received for D2D communication, and wherein a set of common D2D resources is indicated in the system information, the method further comprising : perform D2D communication using the set of common D2D resources; stop D2D communication through the common D2D resource set; and transitioning from an RRC idle state to an RRC connected state; wherein the at least one indicator is configured to transition from the RRC idle state to the RRC connected state, and wherein configuring the at least one indicator comprises configuring a first indicator of the at least one indicator to indicate that a request for the D2D resource allocation is required. 8. Equipment (1700) for wireless communication, the equipment being a UE, characterized by the fact that it comprises: means (1612) for determining whether system information is received for device-to-device, D2D communication; means (1614) for configuring the at least one indicator based on the system information when the system information is received, wherein a first protocol layer of the UE receives the system information and configures the at least one indicator; and means (1616) for determining D2D capabilities based on the at least one indicator, wherein a second protocol layer that is higher than the first protocol layer checks the at least one indicator and requests that the first protocol layer determine the D2D resources. 9. The equipment of claim 8, wherein the system information is determined to have been received for D2D communication, the equipment further comprising: means for determining whether a set of common D2D resources is indicated in the information. system; and means for determining the radio resource control, RRC, state of the UE, wherein the at least one indicator is configured based on whether the set of common D2D resources is indicated in the system information, and based on the state of RRC determined. 10. Equipment according to claim 9, characterized by the fact that the set of common D2D resources is determined to be indicated in the system information, and the RRC state is determined to be an RRC idle state, and wherein the means for configuring the at least one indicator is configured to configure a first indicator of the at least one indicator to indicate to the second layer that a request for an allocation of the D2D resources is not necessary. 11. Equipment according to claim 9, characterized by the fact that the set of common D2D resources is determined to be indicated in the system information, and the state of RRC is determined to be a connected state of RRC, and wherein the means for configuring the at least one indicator is configured to configure a first indicator of the at least one indicator to indicate that a request for an allocation of the D2D resources is necessary. 12. Equipment according to claim 9, characterized by the fact that the set of common D2D resources is determined not to be indicated in the system information, and the RRC state is determined to be an RRC idle state, and in that the means for configuring the at least one indicator is configured to configure a first indicator of the at least one indicator to indicate to the second protocol layer that a request for an allocation of the D2D resources is required. 13. Equipment according to claim 9, characterized by the fact that the D2D resource set is determined not to be indicated in the system information, and the RRC state is determined to be an RRC connected state, and wherein the means for configuring the at least one indicator is configured to configure a first indicator of the at least one indicator to indicate to the second protocol layer that a request for an allocation of the D2D resources is required. 14. The equipment of claim 8, wherein the system information is determined to have been received for D2D communication, and wherein a set of common D2D resources is indicated in the system information, the apparatus characterized by the fact that further comprises: means for effecting D2D communication using the set of common D2D resources; means for interrupting D2D communication through the set of common D2D resources; and means for transitioning from an RRC idle state to an RRC connected state; wherein the at least one indicator is configured to transition from the RRC idle state to the RRC connected state, and wherein the means for configuring the at least one indicator is configured to configure a first indicator of the at least one indicator to indicate that a request for the allocation of D2D resources is required. 15. Memory characterized by the fact that it comprises instructions stored therein, the instructions being executed by a computer to carry out the method as defined in any one of claims 1 to 7.