it is designed for high speed human data connection, and. It ensures that your source code is thoroughly tested at confirmatory level. But similar to America's different, incompatible GSM and CDMA phone systems, there are two different. CDMA stands for Code Division Multiple Access. Some standards also allow for the use of either as both FDD and TDD have their own advantages and disadvantages. It is same as TDD. TDD directs focus on testing. It is proven technology for voice traffic. 11 standards viz. FDD LTE is full duplex, while TDD LTE is half duplex. [citation needed] UMTS-TDD is not directly compatible with UMTS-FDD: a device designed to use one standard cannot, unless specifically designed to, work on the other, because of the difference in air interface technologies and frequencies used. 11 standards viz. n78: 5G Band (3500MHz) Contact Us;. Compared with the traditional TDD, NAFD can provide low-latency services. This is a technique in development that focuses on individual units of a feature that is desired. There are two types of LTE Frequency Bands FDD and TDD. Test Driven Development, or TDD, is a process of developing software where a test is written prior to writing code. TDD and TDMA are both widely used wireless communication technologies that provide efficient and reliable transmission and reception of data. Overall bandwidth is shared among number of stations. 3) Develop the code for that test cases: If the test case fails, then, write the code to make that test. 11. 5 Mbit/s. Each subframe has two slots. TDD. It is a means of communication using one frequency to send and receive information. The advantage of TDD is a simplified and lower cost design, often based upon 802. Time Division Duplex (TDD) accomplishes this using different time slots for uplink and downlink signals over the same frequency. TDD (Time Division Duplex) LTE Bands require only a single band which is used for both the uplink and downlink. Conclusion: TDD and TFD depend on your settings. There are mainly two types of test-driven development – one being ATDD (Acceptance TDD) and the other being DTDD (Developer TDD). This page compares 5G FDD vs 5G TDD and describes difference between FDD and TDD in 5G wireless network. 11 standards viz. With traditional testing, a successful test finds one or more defects. What is Difference between. What are main differences among the Preamble Format ? : Length of Preamble. While that may sound sarcastic, the point is that TDD (as usually practiced) has an implied U on the front, standing for Unit, while the A stands for Acceptance. . On the other hand, CDMA requires both guard time and guard bands. In addition, there must be adequate spectrum separation between the transmit and receive channels. The greater likelihood is that a single UE or mobile will need to detect whether a TDD or FDD. 11 standards viz. NAFD scheme is a free duplex method based on a cellular-free architecture. With FDD, two different carrier frequencies, one from each band, are assigned to a user; one carrier frequency for transmission from the user (also known as upstream, return link, or uplink) and one carrier frequency for reception by the user (also known as. While LTE-FDD uses paired frequencies to upload and download data, LTE-TDD uses a single frequency, alternating between uploading and downloading data through time. Domain Drive Design focuses on understanding the domain (business logic) and Test Driven Design is is an iterative process of writing code for a testing perspective. FR1 (4. 125 GHz) band of frequencies are used for carrying most of the. In the case of differences between FDD and TDD, these differences will be explicitly indicated. It consists of five basic activities, namely, the development of an overall model, the building of a. 11-a,11-b,11-g and 11-n OFDM vs OFDMA CDMA vs GSM Bluetooth vs zigbee. Type 1 is used as LTE FDD frame structure. What is Difference between. In fact, the two LTE versions TDD and FDD are very similar, just the physical layer are different. FDD LTE is more spectrally efficient than TDD LTE, but TDD LTE has a lower latency. ST-Ericsson (M700/M710. 11-a,11-b,11-g and 11-n OFDM vs OFDMA CDMA vs GSM. FDD LTE is more mature than TDD LTE, but TDD LTE is rapidly catching up. Carrier Aggregation (FDD); The LTE-Advanced UE can be allocated DL and UL resources on the aggregated resource consisting of two or more Component Carriers (CC), the R8/R9 UEs can be allocated resources on any ONE of the CCs. TDD increases the initial cost of the project which is compensated only if the project is being maintained for a long. Developers, QAs and Customers involve in this process. There are two sorts of frequencies: uplinks and downlinks. Here's my take on the differences: Waterfall is a software development methodology where each kind of development activity happens in a separate phase (requirements gathering, design, development, testing. FRC. In general, FDD is considered better for coverage and TDD better for capacity Mobile operators are looking to carrier aggregation (CA), which allows them to use multiple sub-6 GHz spectrum channels simultaneously, as a method of increasing the bandwidth and speeds of their 5G networks. FDD LTE Frequency Bands Many chipsets used in modern devices can operate with either FDD or TDD, usually within specific frequency ranges. Both TDD and FDD differ in the way they treat data. So, it is very important to understand the slot structure and other details about slot-based scheduling etc. BDD directs focus on behaviour and specification, and so. While BDD has users or testers produce automated specs connected to the code under test, TDD has developers producing tests. See page 8 of UG-570). You can modify the driver to use the longer calibration counts in TDD mode (TDD uses a 256 count while FDD uses a 1024 count for VCO cals. 531(g) PS BB, 90. In 3G, FDD based implementation is called WCDMA and TDD based implementation is called TDSCDMA. Below is the main difference between Test driven development and traditional testing: TDD approach is primarily a specification technique. Note however that the regulatory aspects are different as well, so both the allowed power levels and bandwidths are generally going to be different for TDD vs. 11 standards viz. This note is for listing all the FRC (Fixed Reference Channel) defined for RF conformance test. g, very wideband and narrow band, TDD and FDD, sub 6 Ghz and mmWave; efficient use of channel reciprocity in TDD (using frequent sounding opportunities). Actually FDD Half-Duplex was discussed even from the initial LTE design, but hasn't gotten much attraction for a long time. View ABC (7). Either of these can be combined with BDD to express tests to be more widely accessible to the variety of stakeholders involved in system development. FDD is a technique which allows use of two separate frequency bands in uplink and downlink. The philosophy behind this practice is that well-written unit tests are a strong indicator of good design and high quality because. Ever since the introduction of GSM, there has been an increasing demand for additional frequency bands. TDD and FDD are two topologies by which critical resources time and frequency are shared among mobile subscribers or terminals. There are various bandwidths supported in LTE. You can also create a combined design document (FDD/TDD) for the entire solution. RF and Wireless TerminologiesThe 3 Methodologies (TDD, DDD, and BDD) The promise of better development through a hybrid solution of multiple methods works – but you can’t utilize just any three. • In FDD mode, both. This blog examines technology drivers, options and considerations related to timing and synchronization, key factors in the planning of 5G networks. 8 Mbit/s, which is an eight-fold increase. 5 GHz band, the uplink peak data rate increases by 18. 2 FR2). TDMA, on the other hand, is a multiplexing technology. So far, TDD has been the most widely used duplexing technique due to its simplicity. 3 Answers. RF and Wireless TerminologiesProgrammers can write unit and functional tests using frameworks. On the other hand, TDD uses the entire channel but alternates between uploading and downloading. Typically, T-Mobile would serve up to 110MHz, while AT&T uses around 40MHz and Verizon uses around 60MHz. 0%DDDSU is the frame structure most suitable in 5G. – Here are the 5 main differences between TDD and BDD: TDD is implemented by Developers and BDD is implemented through collaboration between cross functional members of the team. n261 (28 GHz) TDD. 2. It is a software development process, it is not only about writing tests before code. Time Division Duplex Wireless is a fundamental technology for 5G deployments around the world. 1 Duplex Modes. The main difference between FDD and TDD lies in the use of different duplex modes. Carrier Aggregation (CA) is a technique used in LTE-Advanced to increase the peak data rate (i. FDD is a model-driven short-iteration process that consists of five basic activities. However, recently as IoT /M2M /MTC / Category 0 / Category M/LTE-M over LTE becomes a hot topic, FDD Half-Duplex is coming. Time Division Duplex (TDD) accomplishes this using different time slots for uplink and downlink signals over the same frequency. In TDD collaboration is required only between the developers. When it comes to choosing between BDD and TDD for automation testing, there is no one-size-fits-all answer. For UE with 2Tx (transmit channels) in uplink, with the introduction of. So far, TDD has been the most widely used duplexing technique due to. First there is Frequency Range 1 (FR1), [1] which includes sub-6 GHz frequency bands, some of which are traditionally used by previous standards, but has been extended to. end user devices to be comparatively affordable compared to FDD. In this, only the sharing of time of satellite transponder takes place. Factors such as the project's size, complexity, domain, and lifecycle; the stakeholders. , maximum available speed) of a 4G LTE network. This is a technique in development that focuses on individual units of a feature that is desired. LTE has radio frame of duration 10ms consisting of 10. And since in "old waterfall world" tests come after implementation, then this mindset leads to wrong understanding and behaviour. there are total 20 slots in a radio frame. Other frameworks test that the application works on multiple versions of the targeted operating systems, different screen orientations on. Collaboration is the key for BDD to be successful. Summary: 1. Aug 29, 2013. FDD-LTE (周波数分割二重) と TDD-LTE (時分割二重) は、LTE (Long-Term Evolution) 無線通信技術を実装する XNUMX つの異なる方法です。 FDD-LTE はアップリンクとダウンリンクのデータ送信に別々の周波数帯域を使用しますが、TDD-LTE はアップリンクとダウンリンクに交互のタイムスロットを持つ同じ周波数. An Agile methodology for developing software, Feature-Driven Development (FDD) is customer-centric, iterative, and incremental, with the goal of delivering tangible software results often and efficiently. Then as standards evolve, the FDD benefit will continue to increase with a capacity gain of up to three times and boost the user. This approach enables asymmetric traffic and time-varying uplink and downlink demands. The Work Item considers FDD operation, TDD operation as well as TDD-FDD carrier aggregation operation when applicable. difference between FDM and OFDM Difference between SC-FDMA and OFDM Difference between SISO and MIMO Difference between TDD and FDD Difference between 802. And since in "old waterfall world" tests come after implementation, then this mindset leads to wrong understanding and behaviour. BDD focuses on the system's behavior. Furthermore, the TDD mode, also known as TD-LTE, is designed with coexistence between TD-LTE and TD-SCDMA in mind to simplify a gradual migration from TD-SCDMA to TD-LTE. These so-called. [RAN2] Handover: Study and identify mobility requirements and necessary measurements that may be needed for handovers between some non-terrestrial space-borne vehicles (such as Non Geo stationary satellites)Traditional duplexing TDD and FDD. In FDD operation, two different carrier frequencies are used for DL and UL. Once that is done. Finally, TDD requires more technical knowledge, while BDD aims to make it easier for less technical. BDD is a specification technique based on user stories and test scenarios. Disadvantages with TDD. Language: TDD uses code-based. TDD LTE tốt hơn khi phân bổ lại lưu lượng truy cập so với FDD LTE. Developers, QAs and Customers involve in this process. Video streaming. TDD: 2500: BRS: 2496 – 2690: N/A:(in 20 MHz FDD) 50 Cat3/4 75 Cat5 2119 Cat17 13563 Cat19 (in 20 MHz FDD) LTE-Advanced Pro offers rates in excess of 3 Gbit/s to mobile users. What is Difference between. FDD LTE uses frequency division, while TDD LTE uses time division. 11-a,11-b,11-g and 11-n OFDM vs OFDMA CDMA vs GSM. ATDD. id – Penerapan layanan 4G LTE di Indonesia saat ini sudah cukup besar penyebarannya. In contrast, FDD, or Frequency. Testing proceeds in various categories such as functional, behavior, acceptance, and more. Tdd Versus Fdd. 1st Process: Developing an Overall Model. However, the frequency bands for 5G wireless technology are classified into FR1 and FR2 frequency ranges. 11-a,11-b,11-g and 11-n OFDM vs OFDMA. Guard bands between adjacent channels is necessary. * In TDD, both the transmitter and receiver operate on the same frequency but at different times. Trace (A) represents the case with the shortest SCS (75 Khz) and Trace (D. Log in to reply. Time Division Duplex (TDD) accomplishes this using different time slots for uplink and downlink signals over the same frequency. TDD. Summary for the methodologist: TDD is a design technique for programmers based on unit test first. The main reason for reduced coverage is that the uplink device power is used part of the time for TDD but continuously for FDD . So you can expect TDD. Mainly developers involve in this to write Unit Tests. e. coverage Compared with FDD, the coverage capability is weaker for TDD since its discontinuous signal transmission. - FDD stand for Frequency division duplexing, It separate in frequency the downstream. The test scenarios in TDD is implemented using a programming language. What’s the Difference between TDD and FDD Since 4G Technology is becoming more and more known, most people may know TDD or FDD, but may not. FDD spectrum requires pair bands, one of the uplink and one for the downlink, and TDD requires a single band as uplink and downlink are on the same frequency but time separated. TDD LTE frequency band allocations 4G LTE Technologies LTE Band 41. TDD (ˆ) = 1 L XL ‘=1 TDD H‘ );ˆ: (5) Problem (4) is convex and can be efficiently solved by a simple gradient search, or via a technique known as sum-power iterative waterfilling [29], [30]. 19 17 704 MHz – 716 MHz 734 MHz – 746 MHz FDD 27. FDMA only requires the guard bands between adjacent channels, whereas TDMA requires the guard time of the adjacent slots. Hi! you. See end of the day you need to have a document with technical details like high level design, detailed steps etc. 5G Frequency Bands are defined by the 3GPP, covering FDD and TDD modes, sub-6GHz and millimeter wave (mmWave) bands. The main difference between FDD and TDD lies in the use of different duplex modes. Process Of TDD. . 2. 11 standards viz. 11 standards viz. TDD, specifically the importance of FDD as a key element in network performance. The interferer signal is applied to the transmitter. In FDD topology, different frequencies are used for both uplink and. 6-GHz spectrum, and. BDD is a development technique that focuses on the system’s behavior. Frequency division duplex (FDD) massive multiple-input multiple-output (MIMO) systems introduce a large overhead in downlink channel estimation in contrast to the time division duplex (TDD) mode. FDD is a development methodology based on object model, feature list, dynamic feature teams, and milestones. In this first process, FDD pushes teams to build an object model of the domain problem. FDD, and LTE bands between 33 & 41 are for unpaired spectrum, i. It is designed for symmetric traffic and do not require guard time like TDD. Yet, TDD does not allow the energy transmitter to function continuously, which means to deliver the same amount of energy as that in FDD, the transmitter has to have a higher maximum transmit power. Here are the steps to create an FDD for a D365FO. It is finally time to uncover the mystery between FDD vs. TDD refers to Test Driven Development. So the mobile broadband with the chipsets below will be able support both LTE TDD and FDD. In an emergency situation, where a fraction of a second can make a significant difference, the deployment of a mini-slot can ensure the prompt delivery of vital information. There are two types of LTE Frequency Bands FDD and TDD. Total demand distortion (TDD) is the calculated harmonic current distortion in an electrical system against the full load demand. - TDD stand for Time division duplexing, It separate in time the downstream and upstream directions of the traffic. 5ms duration. Popular answers (1) Emil Björnson. BDD primarily focuses on user behavior. Apa beda TDD dan FDD di 4G LTE. While descriptions are simple and straightforward, the actual code might be complex. Here are the key differences: Focus: TDD focuses on testing the code, BDD focuses on the behavior of the software, and DDD focuses on the domain of the software. ITU Option 3: Flexibility - the bidders for spectrum can decide how they want to allocate the spectrum they acquire to. Disadvantages with TDD. Kanban is better suited for teams that have a lot. Both FDD and TDD are two spectrum usage techniques, both forms of. 5–1 in 3GPP TS 36. However, please leave the first mouth, I have to cross, back 2006 years ago. Frequency range designation: Corresponding frequency range: FR1: 410 MHz – 7125 MHz: FR2-1: 24250 MHz – 52600 MHz: FR2-2: 52600 MHz – 71000 MHzSubject - Mobile Communication SystemVideo Name - FDD and TDDChapter - Fundamentals of Mobile CommunicationFaculty - Prof. Test-Driven Development (TDD), Domain-Driven Design (DDD), Behavior-Driven Design (BDD) and Feature-Driven Design (FDD) are some of the more well known approaches. 5G low-band (below 7GHz frequency division duplex, FDD) is the most commonly deployed band. TDD focuses on the low level, ATDD on high level. In sub 6 Ghz, the maximum bandwidth is 100. More relaxed TDD timing configurations + FDD operation DL Ctrl DL DL Data UL Data UL Ctrl UL Mini-slot Optimized for shorter data transmissions, e. 2. Up to 64-QAM. Bukan hanya itu, ketersediaan smartphone yang mendukung layanan ini dengan harga. 4G experiments, plans to add 237. Many chipsets used in modern devices can operate with either FDD or TDD, usually within specific frequency ranges. FDD LTE idealan je za simetrični promet, dok je TDD LTE idealan za asimetrični promet. FDD significa duplexación por división de frecuencia y TDD significa duplexación por división de tiempo. Each subframe has two slots. 2. 11 standards viz. It can be mathematically expressed as: Total Demand Distortion, TDD =. FDD는 상향링크와 하향링크를 서로 다른 주파수에 배정을 하게 됩니다. Networks on LTE band 20 (LTE-FDD) are suitable for roaming in ITU Region 1 only. g. difference between 3G and 4G difference between 4G and 5G difference between 4. This overhead results in a considerable spectral efficiency (SE) gap between the FDD and TDD modes. Hal ini. TDD is well-suited for smaller units of code, while BDD works well for applications that require you to consider the big picture. To know more about TDD vs FDD refer our article on Difference between TDD and FDD topologies. 2 Mbit/s to 1. TDD is the abbreviated term for Test-Driven Development. 5ms duration. Time-division duplexing (TDD) is a method for emulating full-duplex communication over a half-duplex communication link. For DL carrier aggregation,. BDD focuses on the system's behavior. As a result, there are different LTE band allocations for TDD and FDD. In this approach, we first convert software requirements into unit test cases (a set of actions that verify a specific feature or functionality) before developing the software. 11-a,11-b,11-g and 11-n OFDM vs OFDMA RF heterodyne versus homodyne receiver white noise Vs. BDD is a good approach to go here. LTE FDD uses paired spectrum that comes from a migration path of 3G network whereas TDD LTE uses unpaired spectrum that evolved from TD-SCDMA. resources on the UL, then the power on each RB is less than that of LTE FDD. 3. BDDs are written in Natural language The basics. Figure 1 shows a TDMA/TDD frame structure. To know more on LTE TDD vs FDD, visit our page on LTE TDD Vs FDD modes and go through LTE frame structure in both of these modes. I’m at a stage now where I use all 3. If LTE goes down to 1. While you can initiate a connection to. Frequency Range 1 (FR1) includes sub-6GHz frequency bands, some of which are bands. TDD, specifically the importance of FDD as a key element in network performance. Economically, LTE is a broadband technology, i. difference between FDM and OFDM Difference between SC-FDMA and OFDM Difference between SISO and MIMO Difference between TDD and FDD Difference between 802. In this post, we'll examine two popular Agile methodologies and outline their pros and cons. The specification for true 5G calls for about 1 millisecond, while 4G’s ideal rate is 10ms. As the name implies, involves utilizing tests to guide application development, resulting in simple, iterative implementation with good test coverage right from the start. Key Difference Between LTE FDD vs TDD. eNodeB weights two separate layers at the antenna so beamforming can be combined with spatial multiplexing for one or more UEs Ports 7 and 8 (virtual ports) Dual-layer beamforming, SU-MIMO or MU-MIMO; mandatory for TDD; optional for FDD 9 Eight. example below. Carrier aggregation may be used with both FDD and TDD component carriers. 11 standards viz. Build fast 5G LTE Networks. TDD is a duplexing technology that aims to use the same frequency to provide continuous flow of information in both directions. 6 GHz bands with a TDD carrier in the 2. Hi, I am working on a HW with powered up default in FDD mode. For example in China, the dominant (and at the beginning of commercial LTE, the only) market of TDD LTE, Youtube video. This is a technique of development that focuses on the behavior that is expected. As an example, an 1:1 UL/DL allocation means a duty cycle of ~50% in the uplink which contributes to a ~3dB reduced link budget; In capacity driven deployments, there is no coverage advantage. While TDD is a development methodology, it also comes in handy during automation testing development. Networks on LTE band 8 (LTE-FDD) may allow roaming suitable for roaming in ITU. US 28 GHz. • LTE-A also allows CA of TDD and FDD carriers, inter-band TDD CA with different UL-DL configurations, and CA with multiple uplink timing advance values. LTE-TDD and LTE-FDD are presented and compared in articles [9], [10]. The principal difference in ATDD vs. Currently the bands between 1 & 22 are for paired spectrum, i. The internal enable state machine of device (ENSM) can either be controlled by SPI writes or ENABLE/TXNRX pins. LTE frequency band and arfcn calculator. 3 Hong Kong also used terminals equipped with Qualcomm's Snapdragon X12 LTE processor. An NR FDD cell has been established. Agile is really focused on the overall development process, not just how the code gets. FDD stands for Frequency Division Duplex, each FDD-LTE bands consist of a pair of frequencies, one for the uplink and another for the downlink. View the TI Small cell base station block diagram, product recommendations, reference designs and start designing. 2. Applies to: Dynamics 365. FDD cenderung lebih stabil dan dapat menangani volume data yang lebih besar, sementara TDD lebih fleksibel dan dapat beradaptasi dengan perubahan yang lebih cepat dalam penggunaan jaringan. 1st Process: Developing an Overall Model. The difference is that a device uses two frequencies, one for communications to, and the other for communications from the network, in FDD mode, versus using only one frequency in TDD mode. LTE is the formal name for 4G, meaning Long Term Evolution. Airtel uses the TDD-LTE technology while the Reliance is already using the 1800MHz band along with FDD-LTE technology. FDMA doesn't need any synchronization,. 1. Test-driven development (TDD) is a software development approach that uses the test-first development methodology. The ability to read your tests like a sentence is a cognitive shift in how you will think about your tests. RF and Wireless TerminologiesAbstract and Figures. Test-Driven Designing and building tests for each single function of an application is the first. What is Difference between. 11-a,11-b,11-g and 11-n OFDM vs OFDMA CDMA vs GSM. e. It tests independent small units or objects to make sure each works as intended. 09. TDD (Time Division Duplex) LTE Bands require only a single band which is used for both the uplink and downlink. Let us understand LTE FDD and TDD LTE versions with figures and band example below. g. Some cellular systems use TDD, while others use FDD. TDD provides quasi-simultaneous bidirectional flow of information. The SUL link for uplink data transmission is provided by the NR FDD cell, that is, the SUL and NR FDD co-cell. In short, TDD and Agile really focus on different aspects, and aren't mutually exclusive of one another. . Hence. BDD. 1 NR TDD and NR FDD Timeslot. However, vendors now manufacture devices which include both FDD and TDD capabilities, so in some case you may not expect the price. Both frames are equivalent in terms of throughput and coverage, however the main drawback of using DDDDDDDSUU is having an impact on latency which will be higher. subframes. g. Lower latency means faster response time, and vice versa. Each approach caters to a different need. To understand TDD and FDD, we have started with,Hal. TDD (Time Division Duplex) signifie le duplex par répartition dans le temps et FDD (Frequency Division Duplex) signifie duplex par répartition en fréquence. Choose this topic, I am looking for scold. Note: FR1 and FR2 are often referred to as Sub6 and mmW (millimeter-wave), even though FR1 can now go beyond 6GHz (to 7. On the other hand, CDMA has a high data rate. FDD is an older scheme that was best suited for applications, such as voice, that generate symmetric traffic, while TDD is best suited for bursty, asymmetric traffic, such as Internet or other datacentric services. It is a good approach for project development which are driven by user actions. The paging occasion (subframe) location is different in FDD versus TDD . In TDMA, the time slot allocated to a user does not depend on whether or not the user has any data to be transmitted. TDD is a software development technique which develops the test cases before the software is fully developed and make necessary updates based on test results. e. Tanto FDD como TDD son. . FDD in Agile encourages status reporting at all levels, which helps to track progress and results. But it isn’t quite that simple. Mini-slots allow the 5G frame structure to provide faster response times for certain applications. Our Massive MIMO implementation will directly enable today’s FDD devices to benefit from beamforming. FDD, as we’ve just discussed, works by deploying codes and frequencies to distinguish one user from another. If the feature is implemented in Java, we write JUnit test cases. 예를 들어 우리나라 신문에서 모 이동통신사가 정부로부터 LTE로 20MHz를 할당받았다는 기사가. SAW Devices-Filters, Resonators, DuplexersTDD (ˆ) = 1 L XL ‘=1 TDD H‘ );ˆ: (5) Problem (4) is convex and can be efficiently solved by a simple gradient search, or via a technique known as sum-power iterative waterfilling [29], [30]. 104-5. Both FDD and TDD are two spectrum usage. These various styles are listed here: ATDD, Acceptance Test Driven Development, TDD, Test Driven Development: In test-driven development, writing the test is the thing that’s done first. Please checkout the link -are two ways of implementing the duplex communication. The difference between TDD and TDMA is their main goal. e.