LTE frames are 10 msec in duration. The LTE half-frames are further split into. This type of radio frame has duration of 10ms and consists of 20 slots, with each slot having equal duration of 0. One resource block has duration of 7 OFDM symbols (0. LTE Frame Structure. The GSM frame structure is designated as hyperframe, superframe, multiframe and frame. Each subframe has a length of 1 ms, which comprises 30,720 complex time-domain baseband samples sampled at a rate of 30. - In LTE there is only one subcarrier spacing which is 15kHz whereas in the case of 5G NR multiple subcarrier spacings are defined. As I mentioned in previous section, three different sequences are used as the primary sync signal and there is a one-to-one mapping between each of. In TD-SCDMA a super-frame of 720 ms duration is made of 72 radio frames of 10 ms duration each. LTE frame structure. In the special slot, symbols allocated for downlink, gap and uplink are 10:2:2 respectively. Type 1: FDD : Frequency Division Duplex. They areThis site is for everything on 4G/LTE. 5 ms. 0. THE Mobile Broadband Standard. Figure 10: Frame structure in LTE. Physical layer sampling instant depends on number. The remaining six symbols have a cyclic prefix of length TCP = 144 ⋅ Ts ≈ 4. This video has been taken from our LTE Air Inte. LTE-A Frame Structure. PMP frame to this LTE frame, the downlink start has to align to the beginning of subframe 4, not subframe 0. 10 Variable Subcarrier Spacing Slot configuration 0 Subcarrier spacing (kHz) 15 30 60 120 240 Symbol duration (no CP) (μs) 66. Because of variable subcarrier spacing, the. Page 1. 4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, and 20 MHz. We show that this fixed TTI duration is extremely inefficient whenLTE FRAME STRUCTURE Bikas Singh 5y 5G NR Terminologies – Subcarrier Spacing, Fram-Subframe, Slot and Symbol K. 16e standards WiMAX MAC layer Frame Structure as per OFDM 802. SAE’s main component is the Evolved Packet Core, also known as an EPC. Each frame is divided into ten equally sized subframes. 1 Downlink physical layer The LTE downlink PHY is specified for bandwidths from 1. LTE is one standard developed by organizations from all over the world. OVERVIEW The design of the LTE physical layer (PHY) is heavily influenced by the requirements for high peak transmission rate (100 Mbps DL/50 Mbps UL), spectral efficiency, and multiple channel bandwidths (1. This frame system is used where there are possibilities of heavy rain and snow. • LTE interoperates with CDMA2000, W-CDMA and GSM systems. Frame structure type2 is applicable only to TDD and is provided for compatibility with legacy UTRA TDD systems. OFDMA downlink, Single Carrier Frequency Division Multiple Access (SC-FDMA) uplink 11. The PHY. Selection of a timing reference (beginning of the frame) b. . 6 8. 1 PN sequence 187 9. The tutorial on LTE also covers LTE protocol stack, LTE physical layer, LTE network architecture and so on. crostrip line with a 0. The downlink subframe structure in LTE-M only uses a part of the downlink subframe REs in LTE. 0 MHz, 5. In LTE-Like structure, the reference signal is distribute over both time and frequency domain. Basic time unit Ts for BW of 20MHz, (1/15000)*2048 seconds equal to 32. It only shows the structure of one frame in time domain. OFDM with a cyclic prefix is the basic modulation scheme selected to combat severe frequency-selective multipath fading. Bandwidth will be scalable from 1. 20MHz->1200subcarrier, 15MHz->900, 10MHZ->600, 5MHz->300, 3MHz->180, 1. These are; - Type 1 FDD (Frequency Division Duplexing) - Type 2 TDD (Time Division Duplexing) Type 1: It is designed for frequency division duplex, and is valid for both half duplex, and full. Traditionally, the system models were made using the 3GPP spatial channel model for LTE and a number of parameters have to be varied at the backend. This video looks at OFDM waveforms, and the different subcarrier spacings supported in 5G NR. Hence each subframe has 2 slots. It does not show any structure in frequency domain. Increasing frame configuration; Configuration: 3GPP release: Downlink to uplink switch point. 10 subframes (= 20 slots) are fit into 10 ms in LTE while various number of slots depending on Numerology are fit into 10 ms in 5G NR. CellAdvisor LTE frame analysis — unicast (PDSCH) and broadcast (MBMS) allocations Performance MBMS-SFN services are static and do not vary over time. 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. 36. The resulting location of the process is as shown in Reference Signal section of Downlink Frame Structurepage. This example shows how to create a frame containing the cell-specific reference signals (CellRS) in each subframe. One frame is divided into 10 subframes of 1ms each and each subframe is distributed into 2 slots of 0. 1 Protocol structure over S1 13 6. A common frame structure as defined by 3GPP TS 38. 3. design, LTE frame structure dedicated some channels for data and they are called data channels while others for control information, known as control channels. It uses a 20 MHz channel with 2048 subcarriers. Frame Structure Understanding the 5G NR Physical Layer Waveform, Numerology and Frame Structure 21 – Frame: 10 ms – Subframe: Reference period of 1 ms – Slot (slot based scheduling) • 14 OFDM symbols • One possible scheduling unit - Slot aggregation allowed • Slot length scales with the subcarrier spacing 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. In TDD there are about 7 frame configurations, based on different DL/UL. The STS-1 frame of SDH is composed of section overhead, transport overhead, payload overhead and data part. Full size image. D = downlink sub-frame; U = uplink sub-frame; S = special sub-frame. A resourceThis site is for everything on 4G/LTE. The Evolved UMTS Terrestrial Radio Access Network (E-UTRAN). 39. LTE TDD frame 36. 2. 1. The GSM frame structure is designated as hyperframe, superframe, multiframe and frame. 211 for FDD LTE is as follows. Uplink 3. Instead, we can define the pattern in much more flexible way using several parameters as shown below. LTE defines a generic frame structure that applies to both DL and UL for FDD operation. 1. You would see that the length of PRACH preamble varies depending on the preamble format. Figure 1: LTE Generic Frame Structure [3] 2. 4) is applied to Time Division Duplex (TDD) mode maintaining only full duplex operation. 2. Here, the idea is to compress the whole transmission chain of waiting for a transmit opportunity and preparing for a transmission, transmitting the data, and finally processing the received data. when μ = 0. A new LTE frame type (i. Type 1 uses Frequency Division Duplexing (uplink and downlink separated by frequency), and TDD uses Time Division Duplexing (uplink and downlink separated in time). A TDD frame structure is shown in below figure. The downlink and uplink frame structure parameters are the same, except that the time-domain underlying symbols in the downlink are OFDM symbols, whereas in the uplink the underlying symbols are SC-FDMA symbols due to the use of different multiple access methods in. This is achieved by first identifying the frame start time. 1. If you are interested in some historical aspects of the 5G Frame structure, it would be good to read through this. C. LTE network offers about 300Mbps data. The high-level network architecture of LTE is comprised of following three main components: The User Equipment (UE). The LTE physical layer supports two types of frame structures as types 1 and 2. 8MHZ. The UE uses its f Search spaces in LTE The Base Station (BS) determines a PDCCH format to be transmitted to the UE, creates an appropriate DCI and attaches a CRC. 03255) us. Frame Duration: The duration of an LTE frame is fixed at 10 milliseconds (ms). The type 1 FDD-based radio frame structure is shown in Figure 2. One subframe consists of two slots each having 0. Shukla. 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. For frame structure type TDD the uplink-downlink configuration and subframe number are also required. The LTE physical layer supports two types of frame structures as types 1 and 2. V. 211: “Physical Channels and Modulation” - 3GPP TS 36. LTE standard supports multiple bandwidth (BW) configurations, from 1. LTE Frame Structure. 2. Uplink 3. The NR frame structure supports TDD and FDD transmissions and operation in both the licensed and the unlicensed spectrum. 19/06/2016 0. Sub frame duration=1 ms. It describes the details of the optimization process including performance measurements and troubleshooting mechanisms in addition to demonstrating common. (Please refer to diagram for better understanding) 1) In time domain, 1 Radio frame (RF) is of 10 ms. The second one is called frame structure type 2 and is defined for TDD mode. This will give a big boost as this is about 2. in 1 slot, the number of symbols are fixed that is 14-with normal cyclic prefix (CP) and 12-with extended CP. Each LTE frame has 10 sub-frames (1. But in new subframe, the reference signal is distributed across frequency domain only. 4G/LTE - RRC MIB(Master Information Block) MIB is special signal that carries the following information. 7 μs. What is an LTE frame structure? In LTE, DL and UL transmissions are organized in radio frames of 10 ms each. It describes 5G frame as per NR (New Radio) 3GPP standard. Frame Structure Type 1. Performance Results. There are two cell search procedures in LTE: one for initial synchronization and another for detecting. Instead, we can define the pattern in much more flexible way using several parameters as shown below. It does not show any structure in frequency domain. Introduction The communication scenario in the world is growing at a large pace and the industry is gearing up for a thousand times more faster and reliable data rates. The PSS signal is the same for any given. It usually has the peak at their top. So LTE need to keep the rule set by 802. A. 10. LTE supports two radio frame structures [15]: 1. In TDD (Time division duplex) technique we are using, same frequency or frame for both DL and UL but at a different time. 19. 5 ms each. The LTE standard uses Orthogonal Frequency Division Multiplexing (OFDM) modulation to achieve robust transmission in multipath scenarios (Liu et al. between the air interface—transmitted frames on the air—and the actual service data unit (SDU) packets that are coming from the top of the protocol stack. Performance Results. OFDMA System Model LTE (Long Term Evolution) uses OFDMA and SC-FDMA at downstream and upstream for downlink and uplink transmission. The fig-2 depicts the TETRA frame structure. Each radio frame is divided into 10 subframes (each being 1ms long). The Long Term Evolution (LTE, 4G ) standard defined by the 3GPP supports both FDD and TDD Duplex mode. 55ns. Each half-frame consists of eight 0. LTE-A Frame Structure. 𝜇Each subframe consists of 2 slots of 14 OFDM symbols each. PHICH (Physical Hybrid ARQ (Automatic Repeat reQuest) Indicator Channel) PDCCH (Physical Downlink Control Channel) Available for PDSCH (Physical Downlink Shared Channel) TDD guard period in special subframe. The PRACH transmission is based on the access frame structure. • The PSS is constructed from a frequency-domain ZC sequence of length 63. 211) defines the Frame Structure. The frame can be dynamically configured to any one of the preset configurations shown, depending on the instantaneous data transmission requirement. Frame structure of the LTE resource grid. 5 ms. It improves on those standards' capacity and speed by using a different radio interface and core network improvements. WiMAX physical layer Frame Structure as per 802. No of Slots per Sub frame =2. Type 2: Used in LTE TDD. 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 Evolved Packet Core (EPC). 0 (2007-06): Physical Channels and Modulation. A typical LTE frame is 10 ms (milliseconds) long. 5G NR: Numerologies and Frame structure Supported Transmission Numerologies - A numerology is defined by sub-carrier spacing and Cyclic-Prefix overhead. The air interface described in this book covers the concepts of LTE frame structure, downlink and uplink scheduling, and detailed illustrations of the data flow across the protocol layers. 18th frame) is used as control frame. Calculation: 1 Subcarrier of PRACH preamble =1. Overview - FDD : Frame Structure Type 1 The highest level view from 36. LTE frame structure is enhanced in 5G New Radio (NR) to support users with highly diverse service requirements for enhanced Mobile Broad Band (EMBB), Massive Machine Type Communications (MTC) and. This paper proposes a dual-band transparent antenna using frame-structured metal mesh conductive film (MMCF). The number of symbols per. Expected in the 2008 time frame, LTE is a 3GPP standard that provides for an uplink speed of up to 50 megabits per second (Mbps) and a downlink speed of up to 100 Mbps. Frame Structure There are two types of LTE frame structures. LTE Frame Structure Types. LTE Frame Structure Figure 1 describes the LTE frame structure for TDD mode [4]. How about SSB? We can. Moreover, each subframe is further divided into two equally sized time slots, that is, each slot is 0. I think if we note to general sub-carrier in distinct LTE Bandwidth we are able to identified the answer. Type 1 LTE Frame Structure The basic type 1. 5ms duration. There are two types of LTE frame structure: 1. For the FDD mode of operation, there are two carrier frequencies, one for uplink transmission (f UL) and one for downlink transmission (f DL). One GSM hyperframe composed of 2048 superframes. Figure 3 shows the frame structure for LTE in FDD mode (Frame Structure Type 1). 8 supports scalable RF channel bandwidths from 1. Timing Advance in LTE . SONET/SDH is referred as octet synchronous. End-to-end simulation and conformance testing. One subcarrier has bandwidth of 15 kHz. System Information. Citation 2014). Total Frame duration is about 10ms. We show that this fixed TTI duration is extremely inefficient whenThe radio frame is a key structure defining transmission time slots. LTE frame structure. 3. Initial Cell Search and Cell Selection. Now (as of Sep 2017) 3GPP official specification (38. FDD (Frequency division duplex), which uses type 1 frame structure. 5% LTE TDD Only 7. 16d standard Zigbee RF4CE Frame Structure Zigbee physical layer Frame Structure Zigbee MAC. Type 1 LTE Frame Structure. 5 ms each). 4G/LTE Quick Reference Quick Picture Basic Procedure Troubleshoot Tips. This video talks about LTE Physical Layer and LTE Air Interface. Design verification. RACH Configuration . The minimum unit being frame (or TDMA frame) is made of 8 time slots. 104: “Evolved Universal Terrestrial. Frame Structure 10ms frames 10. LTE RF/PHY RF Measurement. Learn the details of LTE-NB frame structure for downlink operation mode, including the subframe mapping, the reference signal, the NPBCH, NPSS and NSSS. The downlink and uplink frame structure parameters are the same, except that the time-domain underlying symbols in the downlink are OFDM symbols, whereas in the uplink the underlying symbols are SC-FDMA symbols due to the use of different multiple access methods in. The cyclic shifts are generated based on cell-identity group number, which. 5 ms Sub frame duration=1 ms Basic time unit Ts for BW of 20MHz, (1/15000)*2048 seconds equal to 32. It consists of a 10 ms radio frame divided into 20 slots, each with a duration of 0. LTE frame structure type 2 (TDD) One radio frame Tf =10 ms 1 radio frame = 10 ms 1 slot = 0. For FDD, whether downlink and uplink 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. Figure 1. There are six time units: frame, half-frame, subframe, slot. 4G LTE, 5G NR and beyond while continuing to serve as a reliable mobile communication platform in various regions. 3 Context management over S1 14 6. The selection of bandwidth depends on factors like network capacity and available spectrum. Each radio frame consists of two identical 5 ms half-frames. 6 Mobility. The OFDMA system model is shown in Figure 1. The minimum unit being frame (or TDMA frame) is made of 8 time slots. 5ms duration. However, unlike LTE-U, LAA use a special physical layer frame structure called Frame Structure Type 3 which didn't exisit before. (I created following subframe structure using LTE Resource Grid and edited to fit the topics of this page)A frame has a duration of 10 ms and consists of 10 subframes. Learn the basics behind 5G NR waveforms, frame structure, and numerology. frame structure type, number of antennas, number of symbols in PDCCH and the scaling factor Ng. Figure 4shows the structure of a subframe. OFDMA downlink, Single Carrier Frequency Division Multiple Access (SC-FDMA) uplink 11. Selection of SubCarrier Spacing (SCS) d. Frame structure Type 1 is illustrated in the upper portion of Figure 9-66. 11 frequency region. 4. 3) is used for Frequency Division Duplex (FDD) mode; however, the type 2 structure (Fig. Historically, CPRI is mainly designed for 2G/3G and eCPRI is designed for LTE and NR, but it is all up to network infra structure vendors which type of CPRI (CPRI or eCPRI) to use for which radio access technology (i. 5 ms) in the time. We also have a separate sec. Since the modulation format is OFDM (regular OFDM for the downlink, and DFT- precoded OFDM in the uplink. Each radio frame of length Tf = 307200*Ts = 10 ms consists of two half-frames of length Tf = 153600*Ts = 5 ms each. 5 msec. There are two types of LTE frame structure: 1. In the time domain, one LTE frame has a 10 ms period and consists of 20 slots of 0. It consists of 20 equal-sized time slots. For example, TDD networks share the same radio spectrum for the downlink (DL) and uplink (UL) transmissions which means scaling needs to be applied to the expected throughputs. Modulation: OFDM with QPSK, 16 QAM, 64 QAM 10. Frame structure 2 is commonly used. Some of high level description you can get from this figure would be . Other key features of LTE include the following: Carrier aggregation that supports up to 5 component carriers (e. Here are some important parameters and downlink modulation techniques used in LTE: 1. Learn the basics behind 5G NR waveforms, frame structure, and numerology. 7 μs. DCI DCI . Type 2: used for the LTE TDD systems. One slot is defined as 14 OFDM symbols, which corresponds to once a frame or one millisecond in LTE. 7 Physical random access channel for the details. I am happy to share the top articles of ShareTechNote in 2022 for 5G NR, 4G LTE and Engineering Math. Frame-Structure in LTE. 3) is used for Frequency Division Duplex (FDD) mode; however, the type 2 structure (Fig. LTE DL Frame Structure in a Nutshell. 5 99 198 396 397. iv) Transmit every 40 ms , repeat every 10 ms . Type 1: Used in LTE FDD. Transmit Diversity & Receive. 2 Frame Structure and Physical Resources 11 4. · Sub-frame size= 1 ms. ii) System Frame Number (SFN) iii) PHICH Configuration. 2 Physical Resources 12The LTE throughput optimization procedure described in this article requires PDCCH enhancements. The SR is utilized to request the UL-SCH resources to establish a data transmission. iv) System Frame Number for each frame from P-CCPCH (MIB) Once UE get all the information listed above, the timing for other channels can be deduced by the following diagram (This diagram came from 3GPP TS 25. CellAdvisor LTE frame analysis — unicast (PDSCH) and broadcast (MBMS) allocations Performance MBMS-SFN services are static and do not vary over time. Standards for the first and second phases of 5G are moving towards completion, and early deployments can piggy-back on 4G LTE infrastructure. 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. LTE DL Frame Structure in a Nutshell. LTE Frame Structure A frame, which is a major component in LTE commu-nication, is a two-dimensional grid representing time and frequency. One element that is shared by the LTE Downlink and Uplink is the generic frame structure. In LTE, DL and UL transmissions are organized into radio frames of 10 ms each. OFDMA2. · It consists in a category of Frame 2. Uplink physical channels and uplink physical signals are as follows. A large number of physical layer cell identities (IDs) simpli-fy the task of network planning. 2. 2 μs. Downlink modulation types: QPSK, 16-QAM, and 64-QAMthe LTE communication protocol. It enables very low latency, fast HARQ acknowledgments, dynamic TDD, coexistence with LTE and transmissions of variable length (for example, short duration for URLLC and long duration for enhanced MBB (eMBB)). Most of technical materials (or white papers) write several pages in words based on these. Each slots can have a number of symbols (7 symbol for normal CP/ 6 for extended CP for LTE and 14 OFDM symbols in 5G). 75 KHz Subcarrier Spacing. In the frame structure, there are 14 TTIs (Transmission Time Intervals), in which four DMRS (Demodulation Reference Signals) and. No of Slots per Sub frame =2. This page introduces several candiates for 5G Frame Structure before 3GPP finalize the specification. Supporting WiFi and LTE Co-existence Sangki Yun, Lili Qiu The University of Texas at Austin Abstract—Motivated by the recent push to deploy LTE in. 2. In addition, each subframe is further subdivided into two equal time slots, ie each slot is 0. Figure 1 shows frame structure type 1, which can be used in either full-duplex or half-duplex FDD mode. • In downlink (DL) and uplink (UL), NB-IoT supports 15 KHz subcarrier spacing (SCS) frame structure. 11. 8. The type 1 structure (Fig. The skeleton is on example of a frame structure. • A radio frame has duration of 10 ms. The LTE specifications define both FDD and TDD modes of operation. 4 MHz, 3. Yes it brought multiple options in sub-carrier. Frame Structure2. K Upadhayay 1y Insights from the community. MasterInformationBlock ::= SEQUENCE { dl-Bandwidth ENUMERATED { n6, n15, n25, n50, n75, n100},Signal Studio for LTE/LTE-Advanced FDD currently supports only FDD and frame structure type 1. 4G/LTE - MBSFN. · Radio frame size=. No. This article presents an overview of the LTE physical layer with a focus on essential aspects of the physical layer for FDD mode, which is the dominant mode of operation. 6, the downlink subframe structure in LTE consists of an LTE control region and an LTE data region. Low Layer Procedures DCI HARQ PHY Processing MIMO MIMO/CA(Big Pict. Figure 2. In TDD mode, the SF is either of type DL, UL or special (Spc). 3 16. However, regardless of numerology the length of one radio frame and the length of one subfame is same. OFDMA and SC-FDMA 3. The biggest difference of any new wireless communication technology starts from physical layer frame structure. The type 1 structure ( Fig. 4. Type 1 radio frame has a duration 10 ms and consists of equally sized 20 slots each of 0. As mentioned as per topologies, TDD and FDD there are two frame structures viz. 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. This page introduces several candiates for 5G Frame Structure before 3GPP finalize the specification. The first three columns of SONET frame is referred as transport overhead. TD CP Sub Carrier of Configuration Symbol Length each RB 160 @ Slot 0 Normal f=15k CP Hz 144 @ Slot 12 7 1-6 Extended f=15k 512 @. Selection of a special slot configuration Downlink and uplink transmissions are organized into radio frames with 10 ms duration. Time Domain transmission pattern of SS Block in NR is more complicated than LTE SS Block (Actually LTE has only one pattern of SSB Transmission in Time Domain as shown in LTE Frame Structure. The following are the two types of radio frame structures: (i) Type 1: supports FDD mode. 5 ms Sub frame duration=1 ms. LTE-V2X PHY-layer Structure 10 LTE frames divided into 1 subframes Channel divided into resource blocks (RBs) 180 kHz RB contains:. A TDD frame structure is shown in below figure. OFDMA Downlink. However, unlike LTE-U, LAA use a special physical layer frame structure called Frame Structure Type 3 which didn't exisit before. During each frame, there are ten uplink subframes and ten downlink subframes, and uplink and downlink transmissions can occur simultaneously. 55ns. This video looks at OFDM waveforms, and the different subcarrier spacings supported in 5G NR. In this example we will be simulating what happens when a mobile phone is turned on. In LTE TDD, we defined 7 predefined pattern for UL and DL allocation in a radio frame. If you can interpret these tables into a correct graphical format, you already understand all the details of Uplink frame structure. 5 ms duration. The LTE specifications define both FDD and TDD modes of operation. 5 ms. Answer-1:The difference lies in the LTE frame structure in both the FDD and TDD versions of the LTE. Contents. When data is available in the LAA transmission queue, the basestation employs energy detection to sense the wireless channel and determine whether it is busy or idle. Radio Frame Structure. The first choice has the advantage of compatibility with the LTE frame structure used by French networks and The second choice is not compatible with LTE. 27/06/2023 0. FDD and TDD mode can be combined (depends on UE capabilities) in the same physical layer. 4G-LTE packet structure. Each LTE frame has 10 sub-frames (1 ms each) while each sub-frame is further divided into 2 slots (0. The Fig 1: Shows the position of RACH in the Uplink LTE channel Structure. If you are interested in some historical aspects of the 5G Frame structure, it would be good to read through this. Demodulating an LTE Signal in MATLAB with LTE System Toolbox. 0%Abstract: 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. 5 ms each). LTE standard has been published by 3GPP as an extension of UMTS (based on 3GPP standard) and 1xEV-DO (base on 3GPP2 standard) technologies. The frame structures for LTE differ between the Time Division Duplex, TDD and the Frequency Division Duplex, FDD modes as there are different requirements on segregating the transmitted data. Physical Frame Structure of LTE Scheduling is the process of allocating resource blocks to users. The 51-frame structure occurs in several forms, depending on the type of control channel and the network provider’s requirements. Fig.