Transport block size calculation lte. The second step is as follows.


  • Transport block size calculation lte This approach can also be used to create a parameter set with a transport block size that is not standard defined, or when the required transport block size corresponds to a code rate greater than 0. 36. TBS (Transport Block Size) for BL/CE UE is determined by 36. Can someone explain why do we multiply it by 1000? Once you know the coded transport block size, calculate the DL-SCH payload using the rules in TS 36. 4 MHz Outputs : Number of Resource Blocks per slot = 6; Number of Resource Blocks = 120; Number of used subcarriers = 72; Number of FFT points (i. 214 - 5. Nov 17, 2014 · After this step the transport block size index (I_TBS) is derived from the look up table as specified in the LTE phy specification 36. 93). Once the lifting size Z c is determined, the code block size can be calculated, which is 22*Z c for BG1 and 10*Z c for BG2. When the transport block size exceeds a threshold, the transport block is divided into multiple equal size code blocks. 7. 11 and 7. In fifth-generation new radio, the TB size is determined by using a formula due In LTE, we calculate the throughput as: Throughput = TBS (Transport Block Size) * 1000 . The carriers are space 15kHz apart and thus the symbol spacing is 1/15kHz (66. To ensure that a matching TB size can easily be scheduled in the retransmission instance, the reference number of REs is used to How to determine TBS (Transport Block Size) As mentioned above, LTE-NB TBS table are different depending on UL vs DL, SI data or Control/User data as follows. 7 µS). LTE TDD frame configuration. 0000 Throughput(%) for 10 transport block(s) at transmit power 45 LþN 1 be the transport block including the transport block level CRC, where L is the transport block size and N is the transport block level CRC size. It can be performed using lteDLSCH . 5G NR TBS calculation | 5G NR Transport Block size Calculation. 306 Table 5. The TBS (Transport Block Size) calculation is based Qm,R,v and number of REs mentioned in 5G NR 38. FFT size) = 128; 5G NR TBS calculation Author: RF Wireless World Subject: Transport Block Size (TBS) calculation procedure as per 3GPP TS 38. The 3GPP specification 36. 213, table 7. This page mentions 5G NR MCS Table and 5G NR TBS Table as defined in 3GPP TS 38. Tables A1 and A2 list MCS index vs. 101, Annex A. 3 * 2 7 . Mar 25, 2024 · online LTE test online C test Updated or New: Below tool calculates transport block size as per 38. Any signal received at the receiver has a SNR (signal to noise ratio). Aug 16, 2013 · In LTE, the transport block size is a mapping of the CQI, MCS and the allocated PRB and does not depend on the CFI. 213 document. The entire protocol stack for UE and gNB (i. modulation is the modulation scheme for each codeword and nlayers is the number of transmission layers. Transmission Time Interval (TTI): TTI is the time duration for which a certain amount of data is transmitted. In LTE and 5G, the TTI is typically 1 ms. OFDM signal generator: FFT size: 512 minimum, 4094 maximum. 6. If the transport block, including the transport-block CRC, exceeds this maximum code-block size, code-block segmentation is applied before the Turbo coding, as illustrated in Figure 10. Nov 3, 2016 · Transport block size LTE calculation in the Vienna Simulator? I would like to understand the relation between the TB size calculation in the TS36. 213 version 8. This modulation order is defined as a Parameter called Qm in 3GPP and the relationship between MCS value and Qm is defined in a little bit differently for PDSCH and PUSCH in the three tables Oct 17, 2019 · PDSCH Transport Block Size Calculation Procedure DCI format 1_0 or 1_1 carries one field called Imcs, which is used to determine modulation order and coding rate. 30 indicates the best channel quality and 0,1 indicates the poorest channel quality. The differences between Category 11 and 12 for Downlink lies in the layer higher than PHY/MAC and Uplink PHY/MAC throughput(See 36. 214, Transport block size calculation here. 12 Signaling of Transport-Block Sizes. My implementation of the rate matching algorithm is similar to the one I used for the PBCH and PDCCH. LTE Resource Block CALCULATOR EXAMPLE: Input : LTE Channel Bandwidth = 1. This Page provides information about 5G NR TBS (Transport Block size) Calculator. In other words, it means "The code rate is defined as the ratio between the transport block size and the total number of physical layer bits per subframe tha Dec 9, 2023 · Transport Block Size (TBS): Definition: TBS refers to the size of the data block that is transmitted over the air interface in a single transmission time interval. The three tables are listed in - Appendix A of this report. Contents of this video 0:0 Jan 2, 2024 · The Transport Block Size (TBS) determination is a crucial process in wireless communication systems, particularly in the context of LTE (Long-Term Evolution) and 5G (Fifth Generation) networks. It implies that you wouldn't get the where TBS means Transport Block Size. The last step is to take a look at Transport Block Size table to determine how many bits can be transmitted per 1 TTI and multiply it by 1000 to get bps. 213-7. In fourth-generation (4G) long-term evolution, the TB size is determined by using the look-up table [], which is derived by assuming that there are three OFDM symbols in the control region and 11 OFDM symbols in the scheduled duration. 5. 93 (the standard restricts the code rate to be a maximum of 0. TBS index for PDSCH Transport block size or sizes, returned as a column vector of nonnegative integers from the transport block size table in TS 36. For the UL: One coded transport block mapped on up to four layers. Just adding 24 bits of CRC block to the end of the input (transport block). 11ac 802. 214 version 15. 1-2 for Uplink Throughput). 213 Table 16. This test transmission can be decoded with the UE example. Feb 9, 2017 · LTE - PHY - CRC Calculation Lets see the Transport channel functionality on the LTE eNodeB PHY layer. 213. Quality of Service (QoS): The transport block size has implications for Quality of Service (QoS) in LTE. The second step is as follows. DL/UL Throughput calculation for LTE TDD Table. The difference between M1 and legacy LTE lies in mapping between I_MCS and I_TBS and the possible range of I_MCS. TBS for SIB1-NB < 36. Resource Block Size: The size of an LTE resource block can vary, depending on the LTE channel bandwidth configuration. 214 Sections 5. 10. Proper reception of a downlink transmission requires, in addition to the set of resource blocks, knowledge about the modulation scheme and the transport-block size, information (indirectly) provided by the 5-bit MCS field. It explains that the transport block size depends on the modulation and coding scheme (MCS) selected and the number of resource blocks assigned. In fifth-generation new radio, the TB size is determined by using a formula due to large variations of available resource elements (REs) per resource block (RB). 213, Section 7. LTE throughput calculator Example We would like to show you a description here but the site won’t allow us. Based on the SNR a CQI value is calculated. 4). 1 when the transport block is mapped to one spatial layer and the derived transport block size after TBS translation as described in clauses 7. QoS requirements specified by the UE, such as minimum data rates or latency constraints, influence the determination of the optimal transport block size for a given communication session. Transport block segmentation, turbo encoding, rate matching, and code block concatenation procedures defined for LTE [9]. Apply DL-SCH encoding. Jul 13, 2023 · TBS, or Transport Block Size, is a term used in mobile communication networks, particularly in the context of 4G LTE (Long-Term Evolution) and 5G networks. 2 [ 1 ] "Determination of payload size" with target code rate and number of bits per Downlink Throughput is calculated based on 3GPP specs 36. This information is given in the DCI corresonding to the PDSCH transmission. 5 when the transport block is mapped to more than one spatial layer is scaled by Basically the throughput and transport block size at this layer for Category 12 is same as Category 11. 0 (2018-07) Intellectual Property Rights Essential patents IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. In other words, it means "The code rate is defined as the ratio between the transport block size and the total number of physical layer bits per subframe tha Aug 22, 2020 · For the DL: One coded transport block mapped on up to four layers. In LTE there are two sizes defined for code block i. The DL-SCH transport block size is chosen according to rules in TS36. Calculator is based on 3GPP 38. Table consists of TBS size for I TBS in the range from 0 to 26 and N PRB in the range from 1 to 110. 2 and 6. If input transport block In LTE, there are 15 different CQI values randing from 1 to 15 (4 bits) and mapping between CQI and modulcation scheme, transport block size is defined as follows (36. TBS indicates No. It then defines throughput as the transport block Oct 22, 2013 · Since the size of transport block is not fixed, often a question comes to mind as to how transport block size is calculated in LTE. 213 document and in ii) If UE report CQI value 30, it is expected for Network to send data with transport block size of 38576 bits/TTI which is equivalent to around 19 Mbps. Common configurations include 1. If the transport block size exceeds the maximum code block size, the transport block is divided into equal-sized code blocks (with the exception of the last code block, which may be smaller). 0000 Throughput(%) for 10 transport block(s) at transmit power 40 dBm with 1 repetition(s): 80. If L is smaller than or equal to 3824, then N is equal to 16 and p is generated by the following cyclic generator LONG TERM EVOLUTION (LTE) The example presented in Table 343 allocates 8 Resource Blocks for a 500 kbps connection. 5. 11ad wimax Zigbee z-wave GSM LTE UMTS Bluetooth UWB IoT satellite Antenna RADAR Feb 12, 2015 · But on average, approximately 25% are used for overhead channels PBCH, PDCCH, etc, so 75% of that number is in line what what you observed. Both the Dec 13, 2016 · To calculate it more accurately we must to check the 3GPP specs 36. 4. 2, titled, "Determination of payload size", with target code rate, R, equal to 1 / 3, and the number of bits per subframe given by codedTrBlkSize. Modulation Order and Code Rate are determined by tables: 38. increased redundancy improves the reliability of these transmissions. 3. Introduction: Transport Block Size (TBS) is a fundamental parameter in Long-Term Evolution (LTE) networks, governing the amount of data that can be transmitted in a single radio frame. , TB size of 6224 is segmented into two code block The present disclosure relates to sidelink transport block size calculation schemes and associated devices, systems, and methods. Transport channel is present between the MAC & PHY. 4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, and 20 MHz. 3-2 > Apr 28, 2023 · We may all be familiar with hearing the LTE is an OFDM (Orthogonal Frequency Division Multiplexing) scheme used to transmit data reliably over the air. In summary, Transport Block Size (TBS) in LTE networks is a dynamic parameter that determines the size of the data block transmitted over the air interface in a single TTI. One thing you would notice that the transport block size for the highest CQI value is not amount to the ideal MAX throughput defined in 25. The document provides an example where an MCS index of 20 and 2 resource blocks yields a transport block size of 776 bits for 1 ms. The transport block consists of up to million bits. Maximum Turbo code block size – 6144 Maximum Transport block size (for MCS-26 and 110 RBs)- 73376 o TB should be segmented if TB size > 6144 BLER performance is limited by the smallest TB size Coding gain is less Segmentation block ensures that a TB is divided into equal size code-blocks E. 2 Transport block size determination. For this, we need to run the UE example by telling it to decode RNTI 0x1234 and skip SIB2 decoding (because it’s not transmitted by eNB): 5G NR TBS calculation Author: RF Wireless World Subject: Transport Block Size (TBS) calculation procedure as per 3GPP TS 38. 9, thus creating a code block. In fifth-generation new radio, the TB size is determined by using a formula due to large variations of available resource elements ( where TBS means Transport Block Size. 2. From the table with RBs of 100 and TBS index of 26, Transport Block Size is 75376. LTE throughput calculator Example The bandwidth of an LTE resource block is flexible, allowing for adjustments based on the specific requirements of the communication. 213) Table 7. PUSCH Transport block size is influenced by RRC Parameters at the stage of determining Modulation Order and Code Rate and this makes it so difficult and complicated to understand the whole process of TBS(Transport Mar 14, 2023 · This video describes Transport Block size computation in 5G, from MCS and number of Resource Elements (REs) scheduled. BW = 20 MHz Multiplexing scheme = TDD UE category = Cat 3 Modulation supported = per Cat 3 TBS index 26 for DL (75376 for 100 RBs) and 21 for UL (51024 for 100 RBs) TDD frame configuration 2 (D-6, S-2 and U-2) Special subframe configuration 7 (DwPTS-10, GP-2 and UpPTS-2) DL Aug 18, 2017 · Thus the calculation for PHY Data rate in NetSim is based on the Transport Block Size which is specified in the standard. MCS and Modulation Order . Modified 8 years, (This is Transport Block Size per 1 ms for one Antenna) Transport block size or sizes, returned as a column vector of nonnegative integers from the transport block size table in TS 36. Transport Block Size calculation Step-1: Based on MCS, I TBS or TBS index is determined based on table no. Maximum Code Block Size (K_cb): The largest size of a CB that the Low-Density Parity-Check Lifting size is used to identify an allowed code block size, it takes the value of 2, 3, 5, 7, 9, 11, 13, 15 multplied by 2 n. MCS stands for Modulation and Coding Scheme and TBS stands for Transport Block Size. 0 Release 15 2 ETSI TS 138 214 V15. The code block consists of up to 8448 bits. 7. code block size • 6144 bits of max. 4, 7. 213 Table 7. 1-1 which gives Transport Block Size(TBS). PUSCH Transport block size is influenced by RRC Parameters at the stage of determining Modulation Order and Code Rate and this makes it so difficult and complicated to understand the whole process of TBS(Transport Size This 5G NR physical layer provides overview of PHY layer modules as per 5G New radio 3GPP standard. 0000 Throughput(%) for 10 transport block(s) at transmit power 35 dBm with 1 repetition(s): 0. This includes CRC calculation, code block segmentation and CRC insertion, turbo coding, rate matching and code block concatenation. 213 is used to map modulation, transport block size, and resource blocks to calculate peak data rates. 1-1. The data payload from the medium access control layer to the physical layer is referred to as the transport block (TB). Transport Block Size (TBS) Calculation in LTE: A Comprehensive Explanation. In HSDPA, the CQI value ranges from 0 ~ 30. 306-Table 4. Parameters for any MCS index for PDSCH or PUSCH may be obtained by using Tables 7. 214 document. 3-1 > < 36. Apr 1, 2020 · Introduction. Mar 25, 2021 · The scaling factors of 0. 2. Sep 26, 2019 · In fifth generation (5G) new radio (NR), the medium access control (MAC) layer organizes the data into the transport block and transmits it to the physical layer. This page mentions 5G NR TBS determination procedure. 1-1 . Keywords: 5G NR,TBS,Transport block size,calculation,determination Created Date: 8/9/2018 9:49:06 AM Jul 1, 2023 · The first action at the physical layer is the attachment, per transport block, of a CRC (Sect. Another way for LTE throughput calculation is to use Table number 7. If there is a second coded transport block, it is mapped on up to four more layers. You can also look at TS 36. Calculate the transport block size in number of bits. 2-1:Transport block size (TBS) table for NPDSCH carrying SystemInformationBlockType1-NB > TBS for NPDSCH (Signaling Message / User Data) This site is for everything on 4G/LTE. Dec 23, 2012 · Since the size of transport block is not fixed, often a question comes to mind as to how transport block size is calculated in LTE. e. Modulate bits to symbols. CRC Calculation & Attachment: The Output of the Logical layer is referred to as the transport block (TB). 1. Code Rate . The Transport channel functionalities are provided by DSP part of the L1/L2 Chip before feeding the information to RF transceiver. This site is for everything on 4G/LTE. So for the same TBSize (which means same CQI, MCS, allocated PRB), if the CFI is changed (as in case of dynamic CFI) what will happen? is the code rate will be increased or decreased? This is an illustration based on 38. This is an illustration based on 38. Table 387 indicates that TBS index 6 uses QPSK as a modulation scheme so the capacity of a single Resource Block allocation over a subframe is (12*13-6) = 300 bits, when assuming a single OFDMA symbol is allocated to the PDCCH and the cell specific It then shows calculations for maximum throughput with maximum bandwidth of 20 MHz in a 4x4 MIMO configuration, and how throughput is calculated based on symbols per second and modulation type. Apparatus, systems, and methods may determine a transport block size using a number of resource elements for sidelink data. 25 reduce the resultant Transport Block Size which leads to a lower coding rate, i. It describes processing of PDSCH and PUSCH channels through 5G physical layer. 2 . It explains that the transport block size depends on the modulation and coding scheme (MCS) and number of resource blocks assigned to the user equipment. Transport Block Size (TBS) *TS 36. 3. Introduction: 5G NR (New radio) is latest cellular wireless technology which follows 3GPP specifications similar to LTE. So after knowing the I_TBS and N_PRB , there shall be a table look up as specified in LTE phy specification 36. 7 Modulation order and transport block size determination states as follows : NOTE 1 : Transport Block Size is determined by the number of RB and MCS according to TS36. tbs = nrTBS(mod,nlayers,nPRB,NREPerPRB,tcr) returns tbs, the transport block size (TBS), associated with each codeword for a shared channel transmission, as defined in TS 38. layer is referred to as the transport block (TB). Transport Block calculation in LTE Downlink. The 3GPP TS 36. h in NetSim and is per the Maximum number of DL-SCH transport block bits received within a TTI (Note 1) Maximum number of bits of a DL-SCH transport block received within a TTI: Total number of soft channel bits: Maximum number of supported layers for spatial multiplexing in DL: Category 1: 10296: 10296: 250368: 1: Category 2: 51024: 51024: 1237248: 2: Category 3: 102048 Apr 19, 2024 · For this, it needs to know the redundancy version index and the transport block size (from which it can calculate all the sizes that derive from it, such as \(K_\Pi\)). 1-1: Modulation and TBS index table for PDSCH (3GPP TX 36. It refers to the size of the data block that is transmitted from the base station to the mobile device during a specific transmission time Properly configured TBS parameters contribute to the efficiency of the LTE network, ensuring that UEs experience optimal data rates while maintaining a reliable connection. PUSCH Transport block size is influenced by RRC Parameters at the stage of determining Modulation Order and Code Rate and this makes it so difficult and complicated to understand the whole process of TBS(Transport Size How to determine TBS (Transport Block Size) As mentioned above, LTE-NB TBS table are different depending on UL vs DL, SI data or Control/User data as follows. Nov 4, 2018 · In this tutorial we will learn in Telecom How to calculate lte throughput & resource block, how to calculate lte symbol duration, how to calculate lte data r May 24, 2017 · 2) I (UE) wants to get the data with this-and-that transport block size, which in turn can be directly converted into throughput. 1-2. Next, the LDPC base graph to be used is selected based on the transport block size and the coding rate indicated (Sect. 213, section 7. Based upon Table 388, a connection with 8 Resource Blocks can use a transport block size of 552 bits to achieve 500 kbps. Code block segmentation follows. Depending which value UE reports, network transmit data with different transport block Due to restrictions in the internal interleaving, the size of the systematic turbo code block cannot be arbitrary; in fact there is a table of valid code block sizes ranging from 40 to 6144 bits, [1]. 2, 7. 213 sec 7. 20) on the eNB console and hitting Enter. You may know that MCS (Modulation Coding Scheme) is related to Modulation Order (Modulation Depth, e. 1-1 shows the mapping between MCS (Modulation and Coding Scheme) index and TBS (Transport Block Size) index. It is splitting the big transport block into multiple small blocks and add another CRC to each of the split chunks. Keywords: 5G NR,TBS,Transport block size,calculation,determination Created Date: 8/9/2018 9:49:06 AM The above LTE code rate calculator uses all the 11 tables of Transport block size mentioned in the 3GPP TS 36. Back Ground If we only consider "Uplink direction" and we assume that the UE is already attached to the network, then data is first received by PDCP (Packet data compression protocol) layer. 1. 214 Table 5. Table 395 indicates that QPSK is used as a modulation scheme, which is appropriate for cell edge connections Another way for LTE throughput calculation is to use Table number 7. Apr 1, 2020 · The data payload from the medium access control layer to the physical layer is referred to as the transport block (TB). Ask Question Asked 8 years, 9 months ago. Note that p ¼ ½a L,a Lþ1,…,a LþN 1 is the transport block level CRC. 213 MCS Index (Based on SNR Estimation) Number of PRB considered TBS (Maximum PHY Payload Size in bit) Throughput(%) for 10 transport block(s) at transmit power 30 dBm with 1 repetition(s): 0. Table 7. In a post I made a while ago, i showed how to connect a UE to the open source SRSRAN…Continue Reading→ For, DCI format 7-0A/7-0B, the derived transport block size as described in clause 7. Simply put, the code rate can be defined as the ratio of the data rate that is allocated for a subframe and the maximum data rate that ideally can be allocated in the subframe. 8. If the Nov 21, 2017 · 8. Introduction : • TB (Transport Block) is huge in size and hence 5G NR introduces small size units called code blocks to exploit better mechanism for reliable LTE code rate calculator LTE EARFCN vs Frequency converter LTE PCI calculator LTE RB calculator LTE RIV calculator LTE RSRP and RSRQ calculator LTE throughput calculator RF and Wireless tutorials WLAN 802. The document discusses how transport block size is calculated in LTE. 2), say CRC TB, as shown in Fig. They are as follows: • 40 bits of min. 1-1 and Table 5. g, QPSK, 16 QAM, 64 QAM, 256 QAM). Generate new data block or reset buffers in the decoder. This page compares 5G NR TBS (Transport Block Size) vs CBG (Code Block Group) and mentions difference between TBS (Transport Block Size) vs CBG (Code Block Group) used in 5G NR system. 1 for downlink and sec 8. The SNR - CQI Table is available in LTE. First I defined a CQI-transport block size table very similar to Table 7D, but I changed the tranport block size for high end CQI (30, 29, 28, 27) to allocate larger tranport block than the ones specified in Table 7D to push the ideal MAX throughput. 1-1 and table 7. code block size. TBS refers to the size of the payload that is transmitted over the air interface in a single transmission time interval (TTI). The formula or equations used in 5G NR TBS calculation are also mentioned. 9. 0 Release 8 ETSI 2 ETSI TS 136 213 V8. Subcarrier spacing: 15 kHz minimum, 120 kHz maximum. Apr 30, 2020 · The data payload from the medium access control layer to the physical layer is referred to as the transport block (TB). 214. 214 standard. Maximum value of the lifting size is 8448/22 = 384, i. 1a. Table. minimum and maximum code block size. 213) < 36. This calculation is as follows. The LTE Turbo-coder internal interleaver is only defined for a limited number of code-block sizes, with a maximum block size of 6144 bits. Special subframe configuration. The Code Block segmentation. Mar 17, 2020 · When the transport block size exceeds a threshold, the transport block is divided into multiple equal size code blocks. of bits that can be transmitted in one subframe per Transmit Time Interval. 0 (2008-11) Intellectual Property Rights IPRs essential or potentially essential to the present document may have been declared to ETSI. The transport block size is decided by the number of Physical Resource Blocks (N PRB) and the MCS( Modulation and Coding Scheme). Segmentation Criteria: The segmentation process is determined by comparing the transport block size with a specified maximum code block size. Aug 9, 2024 · Transport Block Size (B): The total size of the TB, including the Cyclic Redundancy Check (CRC) bits. 1, which will determine Oct 30, 2017 · After this step the transport block size index (I_TBS) is derived from the look up table as specified in the LTE phy specification 36. ETSI 3GPP TS 38. If the transport block, including the transport-block CRC, exceeds this maximum code-block size, code-block segmentation is applied before the Turbo coding as illustrated in Figure 6. 214 communication standards and allows you to calculate TBS depends on MCS (Modulation order, code rate), number of used PRB etc. PUSCH Transport Block Size Determination . 2-1:Transport block size (TBS) table for NPDSCH carrying SystemInformationBlockType1-NB > TBS for NPDSCH (Signaling Message / User Data) blocks, modulation (QPSK, 16QAM or 64QAM), code rate, and associated transport block size (TBS). 1 for uplink. Base One can modify the transport block size of the test transmission by typing the MCS value (e. Feb 15, 2016 · The document discusses how transport block size is calculated in LTE. Please visit 'Transport Block Size, Throughput and code rate' for detailed description. The maximum transport block size in table 7. 1-1 and Table 7. I programmed Network Simulator so that I decrease the downlink power by a certain steps. 1- 1 [2]. 1-1: Transport block size table as in legacy LTE. To ensure that a matching TB size can easily be scheduled in the retransmission instance, the reference number of REs is used to Jan 24, 2017 · TBS index 6 for a single allocated Resource Block specifies a transport block size of 328 bits. 1-1, 8. 1-2 NOTE 2 : Number of the scheduled subframe mean that the subframe that is scheduled to transmit data. 1-1 is 75376 bits per 1 ms TTI, which is 75 Mbps for SISO also. These block sizes are based on block sizes as supported by the turbo interleaver module of CTC Encoder. It's a number of bits which can be transmitted per 1 TTI (=1ms). PUSCH Transport Block Size Determination. 5 and 0. The maximum length of this output is 38, corresponding to TBS indices from 0 to 37. You can use sliders to change the value of MCS or Resource blocks. g. tion III shows the performance degradation that occurs when Feb 12, 2024 · This Page provides information about 5G NR TBS (Transport Block size) Calculator. wzt aerqg wqyrc xmzak qwwv udpcdhkr uoz lmpfsg cmsdkj iqjlotg