Lte frame structure

Lte frame structure. N/A. LTE frame structure is provided. OFDMA and SC-FDMA. It was combination of Time Domain, Frequency Domain and the modulation scheme. LTE What is LTE Frame Structure? The LTE frame structure is designed to efficiently organize and manage the transmission of data across the network. To develop products that conform to the LTE and LTE-Advanced standards, it’s important to understand the structure of LTE signals, physical layer algorithms such as OFDM and spatial multiplexing, and strategies for simulating and testing your product design. Learn how LTE is one standard developed by organizations from all over the world to support paired and unpaired spectrum deployments. What is an LTE frame structure? In LTE, DL and UL transmissions are organized in radio frames of 10 ms each. There is also a concept of slot, but its definition is different from a slot in LTE. 3) is used for Frequency Division Duplex (FDD) mode; however, the type 2 structure (Fig. However, unlike LTE-U, LAA use a special physical layer frame structure called Frame Structure Type 3 which didn't exisit before. ". 2 LTE Frame Structure The frame structure is dependent on the duplex scheme applied in the spectrum. The duration of one LTE radio frame is 10 ms. The fundamental building block of CPRI frame is called 'basic frame' and 256 basic frames comprises a Hyper frame. We first introduce the LTE signal structure. OFDM with a cyclic prefix is the basic modulation scheme selected to combat severe frequency-selective multipath fading. This structure is similar to frame structure type 2 shown in Fig. FDD is operated in the paired spectrum (see Sect. One frame is divided into 10 subframes of 1ms each and each subframe is distributed into 2 slots of 0. In the frame structure type 3, the downlink transmissions occupy one or more consecutive subframes. Evolved Packet Core (EPC) 4. Frame Structure • Type 1 – Twenty time slots in a frame, each 0. 2 μs. Frame Structure of CPRI is illustrated below. The following text shows the frame structure of each type. The elementaryblock ofanLTE frameis a com-plex symbol, deﬁned as a resource element (RE). LTE is based on OFDM modulation, and mandates the use of MIMO techniques. Frame Structure. The chapter is concerned with the identification, naming and addressing of various entities in 3GPP networks, based on Releases 9 and 10. If the PSS is successfully detected, it means the start of the LTE frame is found and time synchronization can be established. Frame Structure Type1. Jul 24, 2017 · Frame structure. There has been long long discussions on frame structure both in academia and in 3GPP and now we have pretty clear agreements on what a NR(5G) radio frame would look like. LTE Architecture | LTE network architecture. ACK/NACK for downlink transmission, Scheduling Request Indicator (SRI) and feedback of downlink channel quality (CQI) and pre-coding vector. Resource Allocation. 5 ms Sub frame duration=1 ms Basic time unit Ts for BW of 20MHz, (1/15000)*2048 seconds equal to 32. LTE-A Frame Structure Yang Chamsol INHA UNIVERSITY Contents 1. LTE Frame Structure A frame, which is a major component in LTE commu-nication, is a two-dimensional grid representing time and frequency. One Frame is composed of ten sub frames. No of Slots per Sub frame =2. One slot is defined as 14 OFDM symbols, which corresponds to once a frame or one millisecond in LTE. Download scientific diagram | LTE Frame Structure for FDD Systems. However, it is not illustrated as a figure in TS 36. There are two types of LTE frame structures. 1 shows the structure of the LTE Frame [6] in detail. When subframe number hits the max value (i. This is generated by Matlab LTE Toolbox and Refer to Matlab :ToolBox : LTE : Downlink : Cell Specific Reference Signal for the detailed Matlab source. A radio frame (10 ms) consists of 10 subframes (1 ms). I mean there is slight differences in terms of Uplink resource grid (frame structure). host-ed. Frame Structure 2. The radio frame has a length of 10 ms (T frame = 307200 ⋅ T s). Every slot contains either six Download scientific diagram | shows the frame structure of LTE V2X. 1), where the downlink and uplink transmissions are performed in different carrier frequencies. Three different types of physical channels are defined for the LTE system basic parameters and LTE Frame structure: Frame Size=10ms No. Type 1, applicable to FDD- Here there are total 20 slots Oct 27, 2016 · Two distinct frame structures are defined to support both time division duplexing (TDD) and frequency division duplexing (FDD), as well as a third frame structure specifically for license assisted access (LAA-LTE). System Frame Number (SFN) iii) PHICH Configuration. Two very famous resource scheduling techniques named Best CQI and Round Robin are normally used [9]. 1 time slot = 0. Frame Stracture. Hi All,There are lot of new member joined so i am providing the links of ORAN videos whi Aug 12, 2021 · The frame structure is dependent on the duplex scheme applied in the spectrum. But there is some differences between LTE-NB and legacy LTE in terms of structure of uplink signal. Figure 3 shows the frame structure for LTE in FDD mode (Frame Structure Type 1). Numerology – Subcarrier Spacing Frame Structure Type 1. 7. Basic frame structure in LTE is depicted in Fig. 1-2: Frame structure type 1 random access configuration for preamble format 0-3. This structured approach allows LTE networks to efficiently manage and schedule transmissions, optimizing the use of available spectrum and accommodating various types of data traffic with different requirements for bandwidth and latency. One subframe consists of two consecutive slots. Each subframe consists of two slots. 211. pewscorner. nd. – Frame structure type 1 (FS1): FDD. Refer LTE stack >>. Source Code in srsUE . • In downlink (DL) and uplink (UL), NB-IoT supports 15 KHz subcarrier 4G/LTE - RRC MIB(Master Information Block) MIB is special signal that carries the following information. Download scientific diagram | LTE frame structure. Each frame is divided into ten equally sized subframes. 7 μs. Increasing frame configuration; Configuration: 3GPP release: Downlink to uplink switch point LTE Frame Structure 5. 4) is applied to Time Division Duplex (TDD) mode maintaining only full duplex operation. This page covers NB-IoT Frame Structure as per LTE-NB standard. Oct 7, 2023 · In 5G NR, similar to LTE, a radio frame is fixed at 10 milliseconds (ms) and consists of 10 subframes, each of which is 1 ms long. PUSCH Data, Control channel symbols inter-slot hopping frequency diversity. In this page, I will describe on NR Frame Structure that is specified in 3GPP specification (38. It consists of a 10 ms radio frame divided into 20 slots, each with a duration of 0. from publication: Analytical Link Performance Evaluation of LTE Downlink with Carrier Frequency Offset | In this paper, we evaluate the link LTE resource grid. 5, with the differences being in how transmission are scheduled LAA stands for Licence Assisted Access. You don't have to try to understand the details of how this is generated (If you May 11, 2023 · This ensures that the MIB is reliably transmitted over the air interface, meeting the requirements of the LTE standard. The frame structure below is applicable to TDD. 17-22 Mar 11, 2020 · We discuss LTE basics including the LTE frame structure, OFDMA, Resource elements, Resource blocks and Scheduler Resource blocks. 104: “Evolved Universal Terrestrial Radio Access (E-UTRA); Base Station (BS Figure 1 illustrates the structure of the LTE radio frame. For FDD, whether downlink and uplink LTE TDD frame 36. We also have a separate sec In order that the 3G LTE system can maintain synchronisation and the system is able to manage the different types of information that need to be carried between the base-station or eNodeB and the User Equipment, UE, 3G LTE system has a defined LTE frame and subframe structure for the E-UTRA or Evolved UMTS Terrestrial Radio Access, i. WARNING: Scripts must be enabled in your browser for this page to work properly! LTE Mobile communicates with just one base station and one cell at a time and there are following two main functions supported by eNB: The eBN sends and receives radio transmissions to all the mobiles using the analogue and digital signal processing functions of the LTE air interface. It enables very low latency, fast HARQ acknowledgements, dynamic TDD, coexistence with LTE and transmissions of variable length (for example, short duration for URLLC and long duration for eMBB). Learn about the two types of frame structure in LTE, FDD and TDD, and their time units, bandwidths, and special subframes. 4G/LTE - RACH < SIB 2 and 36. LTE frame is 10 ms in duration and consists of 10 subframes. Single Ack/Nack corresponding to 1DLsub frame Nov 20, 2020 · If the LTE UL and LTE DL channels are properly calibrated, the eNodeB can then use the UL channel as an estimate of the DL channel, due to channel reciprocity thats lte resource block architecture. 5. Myung 17 Frame Structure • Two radio frame structures defined. The 协议上对LTE-TDD的帧结构模式，一般称为Frame structure type 2。在TDD中，每个无线帧长度Tf=307200*Ts=10ms，由2个“半帧”组成，每个“半帧”的长度等于5ms，由5个连续的子帧组成，每个子帧长度等于1ms。除了特殊子帧，每个子帧由2个连续的时隙组成。 LTE: Key Features 2. UL Control Channel. It incorporates time, frequency, and space dimensions to optimize resource allocation and ensure robust communication. T s = 1/(1500 x 2048) sec. Introduction: LTE standard has been published by 3GPP as an extension of UMTS (based on 3GPP standard) and 1xEV-DO(base on 3GPP2 standard) technologies. 5 ms or 10 ms periodicity. itelcotech. Then, the PSS and SSS acquisition process is discussed. Like LTE-U, this is a kind of technology to transmit LTE signal in unlicensed frequency range. 2. OFDMA and SC-FDMA 3. The PHY creates slots and sub-frames of transport blocks from the MAC layer. An LTE frame, in turn, is composed of ten 1ms subframes (Figure 1). 3. Downlink ※ Reference - 3GPP TS 36. See diagrams, examples and explanations of the key parameters and concepts. ② SR（Scheduling Request） Scheduling of UL resources is necessary depending on the amount of data to be transmitted by UL. LTE Frame Structure 5. Each frame is divided into ten equally sized subframes of 1 ms in length (Tsubframe = 30720 ⋅ T s). Then, the frame structure for LTE-Advanced is introduced. NR frame structure supports TDD and FDD transmissions and operation in both licensed and unlicensed spectrum. The fre- Download scientific diagram | LTE frame structure used with FDD from publication: Experimental investigation on target detection and tracking in passive radar using long-term evolution signal Download scientific diagram | LTE frame structure and mapping of the pilots of CRS to resource elements. One subcarrier has bandwidth of 15 kHz Basic Frame and Hyper Frame. ITU Pedestrian A channel and ITU Vehicular A channel and also Additive White Gaussian Noise (AWGN) channel are used for The basic structure of a 4G LTE frame is designed to efficiently organize the transmission of data over the wireless communication channel. 75 KHz Subcarrier Spacing. In order that the 3G LTE system can maintain synchronisation and the system is able to manage the different types of information that need to be carried between the base-station or eNodeB and the User Equipment, UE, 3G LTE system has a defined LTE frame and subframe structure for the E-UTRA or Evolved UMTS Terrestrial Radio Access, i. Resource grid; DCI decoder; PDSCH allocation calculator; Scripts retrieved from an archive of www. 25 MHz to 20 MHz. – Frame structure type 2 (FS2): TDD. A se LTE video tutorials covering OFDM, frame structure, Cell mapping, random access procedure. The frame structure is different for FDD and TDD topologies. In this chapter, we introduce the OFDM‐based LTE signal and frame structure to explain how the user‐plane and control‐plane data from the higher layers, such as the Radio Link Control (RLC) layer and Media Access Control (MAC) layer are multiplexed with physical layer control and Reference Signals (RSs) for data transmission. 55ns. LTE Frame Structure. You can check out and see how real life implementation of this process in srsUE source code. Introduction: • The figure-1 depicts overall time frame structure used in NB-IoT AS (Access Stratum). Each subframe has one slot for uplink and downlink each. So far, different schedulers have been (LTE) system according to the Release 8 version of the specifications. com/course/4g-radio-access-network-ranIn 4G LTE, resources at air interfaces are alloca Feb 24, 2024 · In 5G NR, similar to LTE, a radio frame is fixed at 10 milliseconds (ms) and consists of 10 subframes, each of which is 1 ms long. In the frame structure, there are 14 TTIs (Transmission Time Intervals), in which four DMRS (Demodulation Reference Signals) and The 4G LTE frame structure accommodates both Frequency Division Duplexing (FDD) and Time Division Duplexing (TDD) configurations, with key differences in how they manage downlink and uplink transmissions. 211 frame structure type 2 (DL / UL / SSF) Filter. Downlink. LTE Protocol Stack. LTE Jan 1, 2019 · The LTE physical layer supports two types of frame structures as types 1 and 2. This new frame structure is designed to make LTE signal similar to WLAN burst and Aug 29, 2019 · The beauty of 4G LTE Frame structure (or shall i say the complexity of the same) is that everytime we dig a bit deeper into it we will learn something new about it, atleast that is the case with HI all,Please go through video of LTE Frame Structure (FDD and TDD). It is designed to enable the reader to become conversant rapidly with the main principles of the LTE network architecture. 5 ms); one slot consists of seven OFDM symbols. Each half-frame consists of five subframes of length 307200*T s = 1 ms. LTE Frame Structure based on Peak to Average Power Ratio (PAPR) analysis. Uplink 3. LTE-NB frame structure can be summarized as follows. QPSK modulation. 4G/LTE - Access Control Physical Layer : Uplink : Frame Structure; LTE-NB : Physical Layer : Uplink : SC-FDMA Baseband If LTE-NB is your first experience of LTE and come across any concept/terminologies you are not familiar, I would recommend you to refer to pages for legacy (normal) LTE (Try "Search" menu at the top) LTE-NB : Physical Layer : Downlink : Frame Structure; LTE-NB : Physical Layer : Downlink : OFDM Baseband Signal Generation ETSI - Welcome to the World of Standards! Jun 3, 2022 · Frame Structure. MBSFN (Multicast Broadcase Single Frequency Network) With the introduction of mobile device and mobile network, one thing a lot of mobile users wanted to have was "I want to see TV (Movies etc on my mobile phone. Can schedule 1 DL and multiple UL sub-frame at a time. Resource Allocation Note: This is the 2. The word number (W) in a base frame is same but the byte number (Y) is different depending data rate (i. 5 ms. Slot duration=0. 5G NR retains the concept of 10 millisecond frame divided into 10 one-millisecond subframes. Each sub frame lasts for one Transmission Time Interval (TTI). 211 Table 5. Time-Frequency Structure. The air interface described in the chapter covers the concepts of LTE frame structure, downlink and uplink scheduling, and detailed illustrations of the data flow across the protocol layers. 1), where the downlink and uplink transmissions are per-formed in different carrier frequencies. One sub frame is made up of two Apr 3, 2020 · Recommendation No 3: All networks should use the same frame structure at a national level 6 Synchronisation at an international level 8 Recommendation No 4: Networks should be synchronised at an international level whenever possible 8 Recommendation No 5: To manage cross-border coordination, use a common frame structure or consider May 23, 2010 · In the time domain, different time intervals within LTE are expressed as multiples of a basic time unit T s = 1/30720000. the air Dec 27, 2017 · The period of one LTE radio frame structure is 10ms. => 1 frame = 10 x 1sub frame = 10 x 2 x time slot = 10 x 2 x 7symbols (Normal cp) RB (resouce block) in LTE system This site is for everything on 4G/LTE. Learn about LTE, a 4G technology that uses OFDMA and SC-FDMA for downlink and uplink transmission. The chapter concludes with an end‐to‐end procedure of when the UE powers‐up in an LTE network, interchanging data with the network and mobiles around The Long Term Evolution Standard (LTE) is a wireless communications, high-speed data standard for mobile phones and data terminals. A subframe consists of two consecutive slots (0. The LTE architecture consists of LTE EUTRAN and LTE Evolved Packet Core(EPC). Frame Structure - Candidates before 3GPP. 4 and Table 2. 211: “Physical Channels and Modulation” - 3GPP TS 36. Can Schedule 1 DL and 1 UL subframe at a time. Please share this video with your friends The chapter discusses the frame structure for LTE and the structure of the resource block is identified. A new MIB is generated by higher layers when the Radio frame number is a multiple of 4 (RF%4=0). In this video we discuss three focus areas; Downlink Frame Structure, Uplink Frame Structure, and TDD Options. LTE system basic parameters and LTE Frame structure: Frame Size=10ms No. Refer LTE Frame >>. A. Now (as of Sep 2017) 3GPP official specification (38. 4G, 4. This page introduces several candiates for 5G Frame Structure before 3GPP finalize the specification. Tables defining Uplink Frame Structure; Frame When you study the physical frame structure of LTE, you may be impressed by flexibility (meaning complexity in other way) of all the possible ways of resource allocation. Learn about the frame structure of LTE downlink in FDD, TDD and LAA modes, with details on physical channels, symbols, slots and subframes. LTE uses a super-frame of 10 subframes of 1 ms each. The 5G NR frame structure is defined by the 3GPP and here we present details of the NR Frame Structure that is specified in 3GPP specification (38. See illustrations and tables of the LTE physical layer terminology and signals. 5G, and 5G are covered in subsequent modules. In addition, there is a new unit called RU(Resource Unit) that exisits in LTE-NB but not used in legacy LTE. e, CPRI option). lecture in a series of lectures on 1G to 5G. See full list on rfwireless-world. ** 4G LTE Course link with special offer is - https://www. See examples, diagrams and tables to understand LTE frame structure and its applications in 4G networks. Physical, MAC, RLC, PDCP and RRC as shown in the figure. Understand the concepts of PCFICH, PHICH, PDCCH, MCS, TPC and PDCCH aggregation levels. The LTE services were launched by major North American carriers as well, with the Samsung SCH-r900 being the world's first LTE Mobile phone starting on September 21, 2010, [11] [12] and Samsung Galaxy Indulge being the world's first LTE smartphone starting on February 10, 2011, [13] [14] both offered by MetroPCS, and the HTC ThunderBolt offered 2. Two duplex schemes FDD and TDD are supported. The LTE frame structure consists of 10 subframes, each with 2 slots of 0. However, unlike LTE, which has a fixed subcarrier spacing (SCS) of 15 kHz, 5G NR supports scalable numerology for more flexible deployments covering a wide range of services and carrier frequencies. For the normal mode, the first symbol has a cyclic prefix of length TCP = 160 ⋅ Ts ≈ 5. 101: “Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) radio transmission and reception” - 3GPP TS 36. This page describes LTE network architecture with system elements. The type 1 structure (Fig. 211). When I was first reading LTE materials, almost every books and article says "LTE use SC(Single Carrier) FDMA for uplink signal" and because of the word 'Single Carrier' made me so confused about creating any images of Uplink slot structure. . This site is for everything on 4G/LTE. See the analysis of 3GPP submissions and the technical specifications that define LTE. FDD is frequency division duplex which have different frequencies for both DL and UL at a same time. 1. Check out the Episode 13 of Field Journal to get answers to questions like: 따라서 하나의 sub frame은 14개의 symbol을 갖는다. me. Each two consecutive time slots are combined as one LTE generic uplink subframe structure with normal cyclic prefix. Its basis stands in the GSM/EDGE and UMTS/HSPA network technologies, with changes in terms of an increased capacity and higher speed by simplifying the core network and using a different radio interface. PUCCH, PUSCH and demodulation RS. An LTE signal is organized in frames of 10ms. There are two types of frames in LTE;FDD and TDD. The first subframe of each radio frame or subframe-0 is represented by the grey boxes in the diagram. In this LTE Frame structure video tutorial i have explained the all the units of f Fig. DL Control Channel. > LTE TDD UPLINK AND DOWNLINK CONFIGURATION, LTE TDD FRAME, Long CP Time slot, Short CP Time slot, TIME UNIT IN LTE, LTE FDD FRAME, lte frame structure, LTE FDD FRAME: FDD Frame used for FDD technology. from publication: A modified CA-CFAR method for LTE random access detection | Random Access is an important aspect of mobile Figure 1: LTE Generic Frame Structure [3] 2. 1 Downlink physical layer The LTE downlink PHY is specified for bandwidths from 1. Since LTE-NB is considered as a LTE family, it has some commonalities with the legacy LTE as follows : The length of a subframe is 1 ms; One Radio Frame is made up of 10 subframes LTE: Key Features. Learn how LTE frame structure varies depending on TDD or FDD configuration, and how slots and subframes are organized. The useful symbol time is Tu = 2048 ⋅ Ts ≈ 66. Resource Allocation Note: This is the 2nd lecture in a series of lectures on 1G to 5G. The Uplink slot structure looks as follows. The Technical Overview of 3GPP LTE| Hyung G. However, unlike LTE, which has a fixed subcarrier spacing (SCS 4G-LTE Packet Structure. 5 ms long – A subframe consisting of two slots – Ten subframes for DL and 10 for UL • Type 2 – Two half-frames in a frame, each 5 ms long – A half-frame consisting of 5 subframes – A subframe consisting of 2 slots 5G Frame Structure in Detail. Each radio frame of length T f = 307200*T s = 10 ms consists of two half-frames of length T f = 153600*T s = 5 ms each. There is no copyright In LTE, the arm ticking in 10 ms interval has numbers between 0 and 1023 and these numbers are called SFN (System Frame Number) and the other arm ticking in 1 ms interval has numbers between 0 and 9, and this number is called subframe number. 5ms = 7 OFDM symbol (Normal cp) = 6 symbols (extended cp) 정리하면 하나의 frame에는 총 140개의 symbol을 갖게 된다. iv Oct 22, 2018 · In this tutorial we will learn about TELECOM LTE FRAME STRUCTURE in hindi. from publication: Multipath tracking with LTE signals for accurate TOA estimation in the Aug 29, 2019 · The beauty of 4G LTE Frame structure (or shall i say the complexity of the same) is that everytime we dig a bit deeper into it we will learn something new about it, atleast that is the case with But there is some differences between LTE-NB and legacy LTE in terms of structure of uplink signal. Tables defining Uplink Frame Structure; Frame This site is for everything on 4G/LTE. It is composed of 20 slots of 0. • A radio frame has duration of 10 ms. • A resource block (RB) spans 12 subcarriers over a slot duration of 0. Nov 30, 2018 · 5G NR: Numerologies and Frame structure Supported Transmission Numerologies - A numerology is defined by sub-carrier spacing and Cyclic-Prefix overhead. com Nov 9, 2022 · Learn how LTE frames, sub-frames, slots, symbols, resource elements, blocks, groups and channels are organized and used for data transmission. Engineers involved in the design of LTE interfaces and network equipment, as well as those involved in the first This updated value then serves as the threshold for the next chunk. LTE is designed to efficiently transmit packets of information with low latency (a few milliseconds). of slots=20. cyclic prefix). Frame-Structure in LTE In LTE, DL and UL transmissions are organized into radio frames of 10 ms each. Frame Structure - UL . This Video Explains the LTE technology basics, OFDMA and LTE Frame Structures and types. 10 ms radio frame, 1 ms sub frame. IP packets are reformed in the PDCP SDUs and flow through the RLC, MAC, and PHY layers. 5 ms duration. It describes NB-IoT Frame Structure with 15 KHz Subcarrier spacing and 3. The duration of … - Selection from LTE, LTE-Advanced and WiMAX: Towards IMT-Advanced Networks [Book] cyclic prefix). 5ms each. Switching Points. The stack consists of different layers viz. - In LTE there is only one subcarrier spacing which is 15kHz whereas in the case of 5G NR multiple subcarrier spacings are defined. Type 1: Used in LTE FDD. e, 9), it goes back to 0 and SFN number get increased by 1. The biggest difference of any new wireless communication technology starts from physical layer frame structure. Scheduling is done on a subframe basis for both the The last frame structure is type 3, which is applicable to LAA secondary cell operation. All three frame types have the same basic structure shown in Fig. We Nov 25, 2015 · Frame Structure in LTE; NEED ON/OR/OP in RRC; LTE Procedure's; RAN Work Group; System Information in LTE October (2) September (4) Visitors. If you are interested in some historical aspects of the 5G Frame structure, it would be good to read through this page. Type 2: Used in LTE TDD. e. LTE Frame structure. This video has been taken from our LTE Air Inte Jun 17, 2022 · There are two types of LTE frame structures. the air May 6, 2021 · This episode of Field Journal we’ll go deep into the TDD-LTE frame structure in the CBRS spectrum band, and touch on the different 4G LTE deployment methods that are used in different environments. The remaining six symbols have a cyclic prefix of length TCP = 144 ⋅ Ts ≈ 4. Jul 3, 2020 · Exploring the 5G NR Frame Structure used in 5G New Radio networks and 5G Radio equipment: including gNodeB and 5G CPE devices . 2. 211) defines the Frame Structure. Type 1, applicable to FDD- Here there are total 20 slots TDD: Frame Structure Type 2: TDD的帧结构与FDD的帧结构都是一样的，但对于TDD，上下行用相同的频带，在一个频带内上下行占用的时间可根据需要进行调节，因此TDD模式会有多种配比，如下表。 < LTE Downlink Refence Signal - Sequence Generation > One example of reference signal symbol data is as follows. Figure 1 shows frame structure type 1, which can be used in either full-duplex or half-duplex FDD mode. zjvtwk kdcrl yaljak qztkbl vqygk wdgbxh ocyff lzlidf sho lgbveq