Bsnl Training Essay Example

Bsnl Training Essay A TRAINING REPORT ON BROADBAND SERVICES - SUBMITTED TO: SUBMITTED BY: Training Placement Cell MUDIT GUPTA (S. D. COLEGE OF ENGG. BRANCH – C. S. TECHNOLOGY) SEM. – VII CERTIFICATE This is to certify that the training report entitled bSNL bROADBAND SERVICES submitted is a bonafide study work carried out by MR. MUDIT GUPTA under the supervision and guidance of SH. K. P. SINGH. During training period, trainee has learnt about overall exposure of RLU exchange, telecommunication network and bsnl broadband and 3G services. MUDIT GUPTA is a student of b. tech ivth year, S. d. College of engineering and technology, muzaffarnagar(u. p. ) . He has attended the b. s. n. l, Shivchowk, Exchange, Muzaffarnagar for six weeks. ACKNOWLEDGEMENT I am very much thankful and want to express my profound gratitude in respect of Computer Engineers, b. s. n. l. ,mzn, who permitted me for the practical training in their Department. I am also grateful to all Technical Staff of B. S. N. L. whose transcendent thoughts were the tremendous source of inspiration and encouragement, which will be definitely important for me as far my future is concerned. They explained primary techniques in a very easy manner. I also extend my gratitude to whole staff of B. S. N. L. , Muzaffarnagar, for their kind cooperation. CONTENTS Page No.  ¦ Company Profile 4-5  ¦ Vision, Mission and Objectives 6  ¦ Broadband Services 9 Technology Used 10  ¦ Wired Line 11-17  ¦ Wireless Line 18-26  ¦ Bibliography 12 COMPANY PROFILE On October 1, 2000 the Department of Telecom Operations, Government of India became a corporation and was christened Bharat Sanchar Nigam Limited (BSNL). We will write a custom essay sample on Bsnl Training specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Bsnl Training specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Bsnl Training specifically for you FOR ONLY $16.38 $13.9/page Hire Writer Today, BSNL is the largest Public Sector Undertaking of India and its responsibilities include improvement of the already impeccable quality of telecom services, expansion of telecom network introduction of new telecom services in all villages and instilling confidence among its customers. Bharat Sanchar Nigam Ltd. formed in October, 2000, is Worlds 7th largest Telecommunications Company providing comprehensive range of telecom services in India: Wireline, CDMA mobile, GSM Mobile, Internet, Broadband, Carrier service, MPLS-VPN, VSAT, VoIP services, IN Services etc. Presently it is one of the largest leading public sector unit in India. BSNL has installed Quality Telecom Network in the country and now focusing on improving it, expanding the network, introducing new telecom services with ICT applications in villages and wining customers confidence. Today, it has about 47. 3 million line basic telephone capacity, 4 million WLL capacity, 48. 11 Million GSM Capacity, more than 37382 fixed exchanges, 44966 BTS, 3140 Node B ( 3G BTS), 287 Satellite Stations, 480196 Rkm of OFC Cable, 63730 Rkm of Microwave Network connecting 602 Districts, 7330 cities/towns and 5. Lakhs villages. BSNL is the only service provider, making focused efforts and planned initiatives to bridge the Rural-Urban Digital Divide ICT sector. In fact there is no telecom operator in the country to beat its reach with its wide network giving services in every nook corner of country and operates across India except Delhi Mumbai. Whether it is inaccessible areas of Siachen glacier an d North-eastern region of the country. BSNL serves its customers with its wide bouquet of telecom services. BSNL has set up a world class multi-gigabit, multi-protocol convergent IP infrastructure that provides convergent services like voice, data and video through the same Backbone and Broadband Access Network. At present there are 0. 6 million DataOne broadband customers. The company has vast experience in Planning, Installation, network integration and Maintenance of Switching Transmission Networks and also has a world class ISO 9000 certified Telecom Training Institute. BSNL cellular service, CellOne, has more than 49. 09 million cellular customers, garnering 16. 98 percent of all mobile users in its area of operation as its subscribers. In basic services, BSNL is miles ahead of its rivals, with 35. 1 million Basic Phone subscribers i. e. 85 per cent share of the subscriber base and 92 percent share in revenue terms. BSNL plans to expand its customer base from present 47 millions lines to 125 million lines by December 2007 and infrastructure investment plan to the tune of Rs. 733 crores (US$ 16. 67 million) in the next three years. The turnover, nationwide coverage, reach, comprehensive range of telecom services and the desire to excel has made BSNL the No. 1 Telecom Company of India. VISION, MISSION OBJECTIVES VISION: To become the largest telecom Service Provider in   Asia. MISSION: To provide world class State-of-art technology telecom services to its customers on demand at competitive prices. To Provide world class telecom infrastructure in its area of operation and to contribute to the growth of  the  countrys economy. OBJECTIVES: (1) To be the Lead Telecom Services Provider. (2) To provide mobile telephone service of high quality and become no. 1 GSM operator in its area of operation. (3) To provide point of interconnection to other service provider as per their requirement promptly. 4) Contribute towards: (i) National Plan Target of 500 million subscriber base for India by 2010. (ii) Providing telephone connection in villages as per government policy. (iii) Implementation of Triple play as a regular commercial proposition. (5) To facilitate R D activity in the country. Voice The majority of all telecommunication today uses Digital techniques, and the dominance of digital is so strong that in this text we will neglect Analog communication almost completely. When communicating voice digitally, the sound waves in the air must be digitalized. This is done by sampling the sound waves: measuring their shape, and converting this measurement into numbers. These numbers are a digital form of the voice signal. At the receiver, the measurement values (called samples) are used to reconstruct the original sound wave. To be able to reconstruct the voice with sufficient quality, the number of samples taken (called the Sampling-rate) and the accuracy of each sample (called the Resolution) must be sufficient. This is a trade-off, because the more samples, the more digital numbers needs to be transmitted, and this costs money. As a good compromise for understandable voice, the telecom community agreed to take 8000 samples per second, each 8 bits precise. This will not result into perfect audio-quality, but it is enough to understand the person on the other side of the line. As you are converting the sound waves to digital numbers, you create a continuous stream of information flow: every second you generate transport terminate 8000*8 = 64000 bits. This amount is called the Bit-rate. As a result a single digital voice connection is often referred to as a 64 kbps (kilo-bits-per-second). This continuous stream lasts as long as the phone conversation lasts, typically a few minutes. Note: As a comparison, an audio CD signal uses 44100 samples per second, each 16 bit precision, and two channels (left+right) to provide stereo. You will agree that CD sound quality is much better than a phone-line, but the price for this is that you need to transport 1. 411 Mbps for the CD (mega-bits-per-second), where only 64 kbps for a telephone line. Data When computers or machines communicate with each other, they usually dont send a continuous stream of information. Typically a computer needs some limited input data, then processes this, and responds with a limited amount of result data. Therefore data communication is using the concept of information packets a group of information bits. So one computer sends a packet of input to the other computer, which processes it, and then returns a packet with the results. BROADBAND SERVICES Broadband is often called high-speed Internet, because it usually has a high rate of data transmission. In general, any connection to the customer of 256 kbit/s (0. 256 Mbit/s) or more is considered broadband Internet. The Organization for Economic Co-operation and Development (OECD) has defined broadband as 256 kbit/s in at least one direction and this bit rate is the most common baseline that is marketed as broadband around the world. Telecommunication regulatory authority of India(TRAI) defines broadband as â€Å"an always on data connection that is able to support interactive services including internet access has the capability of the minimum download speed of 256Kbps to an individual subscriber from the point of presence of the service provider intending to provide broadband service where multiple uch individual broadband connections are aggregated the subscriber is able to access these interactive services including the internet through the POP. The interactive services will include any services for which a separate license is specifically required. For example- real time voice transmission, except to the extent that it is presently permitted under ISP license with internet Telephony†. TECHNOLOGY USED Broadband access technology is classified into two categories: Wired Line * DSL (Digital subscriber’s line) * Cable Modem * PLC (power line communication) * Optical fibre technologies Wireless Line * 3G Mobile Wi-Fi (Wireless fidelity) * Wi-Max * FSO (Free space optical) * LMDS MMDS * Satellite Wired Line: * DSL: Digital subscriber lines apply modern digital techniques on twisted pair medium to deliver new services over existing infrastructure. The bandwidth and quality of a typical analog telephone line is relatively low (300 3400 Hz). This is mainly because there is a wide variety of types, lengths, qualities, etc of twisted pairs used, and an analog line must assume the worst-case common denominator of all. However, todays more powerful signal processing and computing techniques allow building equipment hat adapts to each particular twisted pair, optimizing the use of it case by case, and resulting in much higher throughputs. For the Telecom operator, the advantages are: * No additional cable-cost: uses existing telephone line. * Telephone network is not used for data-services, like accessing the Internet. Telephone networks are dimensioned for phone calls, not for accessing the Internet. For example the average phone call duration is 100 seconds, when surfing the Internet this is much longer, resulting in congestion in the telephone network. Advantages for the end-user: High throughput up to Mbps. * Telephone is still available when surfing the Internet, telephone and data-services can be used at the same time. HDSL XDSL is a family name for a number of similar techniques. The x is a placeholder for several variants of Digital Subscriber Line (DSL). The first one, which was developed, was High Speed Digital Subscriber Line (HDSL) It is a symmetrical technique, the same bandwidth is available in both directions. HDSL is typically deployed in the network where 2. 048 Mbps are needed, but only twisted pair (no coax or fiber) is a vailable. ADSL Asymmetrical Digital Subscriber Line (ADSL) is the best-known variant of XDSL: The main principles are the same, but the bandwidths are divided Asymmetrical: more bandwidth is made available from network to user (Downstream) then from network to user (Upstream). This matches with typical residential applications, Such as: * Video-on-Demand (VOD): video, typically a few Mbps going downstream, with the user control (selecting the video, play, stop, rewind, etc) only a few kbps going upstream. * Internet: WEB-contents going downstream are megabytes; user requests are only a few hundred bytes. Figure: Internet Access Provider, ADSL VDSL Digital subscriber lines make a trade-off between bandwidth and distance: the shorter the line, the higher the throughput. As a result of this, a number of variants of DSL-techniques are being developed, from long distance – low bandwidth to short distance high bandwidth. Another parameter is the division of Upstream/Downstream bandwidth. This can be: * Symmetrical: the same in each direction, * Asymmetrical, fixed * Asymmetrical, dynamic: the total bandwidth, upstream+downstream is fixed, but at any time this total can be assigned in a certain ratio to either direction. New DSL variants using these new techniques are called Very High Speed Digital Subscriber Line (VDSL) Figure: Different DSL technique CABLE MODEM A cable modem with a splitter can provide Internet access to multiple PCs, if they are connected via a LAN. * Tuner converts TV channel to a fixed lower frequency (6 to 40 Mhz). * Demodulator performs A/D demodulation, error correction MPEG synchronization. * MAC extracts data from MPEG frames, filters data for other cable modem, runs the protocol. * Burst modulator performs RS encoding modulation frequency conversion/A conversion. Interface can be PCI bus, universal serial bus, Ethernet or others. Figure : -Cable Modem POWER-LINE COMMUNICATION(PLC) This is a new service still in its infancy that may eventually permit broadband Internet data to travel down standard high-voltage power lines. Broadband over power lines (BPL), also known as Power line communication, has developed faster in Europe than in the US due to a historical difference in power system design philosophies. Nearly all large power grids transmit power at high voltages in order to reduce transmission losses, then near the customer use step-down transformers to reduce the voltage. Since BPL signals cannot readily pass through transformers, repeaters must be attached to the transformers. In the US, it is common for a small transformer hung from a utility pole to service a single house. In Europe, it is more common for a somewhat larger transformer to service 10 or 100 houses. For delivering power to customers, this difference in design makes little difference, but it means delivering BPL over the power grid of a typical US city will require an order of magnitude more repeaters than would be required in a comparable European city. The second major issue is signal strength and operating frequency. The system is expected to use frequencies in the 10 to 30 MHz range, which has been used for decades by licensed amateur radio operators, as well as international shortwave broadcasters and a variety of communications systems (military, aeronautical, etc. ). However there are some disadvantages of using PLC communication: N/w characterstics devices can advesely affect signal strength quality. Electronic loads nearby high frequency radiation sources may cause high frequency noise that interferes BPL. Some PLC systems are not fully operable at very low or no load without battery backup. Physics limits frequency on power lines to ; 100 Mhz. BPL is not likely to be available soon for high voltage(;66Kv)power lines. Conventional electronic surge arrestors severely attenuate BPL signals. OPTIC-FIBRE TECHNOLOGY Currently fibre costs are high as compared to copper but there is a trend towards decreasing costs of optical fibre cables and photonics employed. To carry same information as one fibre cable we would need hundreds of reels of twisted wire copper cables. Fibre is 23 times lighter than copper cable 36 times less in cross section. Advantages Of Optic-Fibre Communication: Small Size and Weight: Optical fibers have very small diameters which are often no greater than the diameter of a human hair. Hence, even when such fibers are covered with protective coatings they are far smaller and much lighter than corresponding copper cables. This is a tremendous boon towards the alleviation of duct congestion in cities, as well as allowing for an expansion of signal transmiss ion within mobiles such as aircraft, satellites and even ships. †¢ Signal Security: The light from optical fibers does not radiate significantly and therefore they provide a high degree of signal security. Unlike the situation with copper cables, a transmitted optical signal cannot be obtained from a fiber in a noninvasive manner (i. e. without drawing optical power from the fiber). Therefore, in theory, any attempt to acquire a message signal transmitted optically may be detected. This feature is obviously attractive for military, banking and general data transmission (i. e. computer network) application. †¢ Ruggedness and Flexibility:- Although protective coatings are essential, optical fibers may be manufactured with very high tensile strengths. Perhaps surprisingly for a glassy substance, the fibers may also be bent to quite small radii or twisted without damage. Furthermore cable structures have been developed which have proved flexible, compact and extremely rugged. Taking the size and weight advantage into account, these optical fiber cables are generally superior in terms of storage, transportation, handling and installation to corresponding copper cables, whilst exhibiting at least comparable strength and durability. †¢ System Reliability And Ease Of Maintenance :- These features primarily stem from the low loss property of optical fiber cables which reduces the equirement for intermediate repeaters or line amplifiers to boost the transmitted signal strength. Hence with fewer repeaters, system furthermore, the reliability of the optical components is no longer a problem with predicted lifetimes of 20 to 30 years now quite common. Both these factors also tend to reduce maintenance time and costs. †¢ Enormous P otential Bandwidth: The optical carrier frequency in the range 1013 to 1016 Hz (generally in the near infrared around 1014 Hz or 105 GHz) yields a far greater potential transmission bandwidth than metallic cable systems. i. e. coaxial cable bandwidth up to around 500 MHz) or even millimetre wave radio systems (i. e. systems currently operating with modulation bandwidths of 700 MHz ). At present, the bandwidth available to fiber systems is not fully utilized but modulation at several gigahertz over a hundred kilometers and hundreds of megahertz over three hundred kilometers without intervening electronics (repeaters) is possible. Therefore, the information – carrying capacity of optical fiber systems has proved far superior to the best copper cable systems. Wireless Line: * Bluetooth: Bluetooth is a standard and communications protocol primarily designed for low power consumption, with a short range (power-class-dependent: 1 meter, 10 meters, 100 meters) based on low-cost transceiver microchips in each device. Bluetooth enables these devices to communicate with each other when they are in range. The devices use a radio communications system, so they do not have to be in line of sight of each other, and can even be in other rooms, as long as the received transmission is powerful enough. Bluetooth exists in many products, such as telephones, printers, modems and headsets. The technology is useful when transferring information between two or more devices that are near each other in low-bandwidth situations. Bluetooth is commonly used to transfer sound data with telephones (i. e. with a Bluetooth headset) or byte data with hand-held computers (transferring files). Bluetooth protocols simplify the discovery and setup of services between devices. Any Bluetooth device can, in theory, host any other Bluetooth device. This makes using services easier because there is no longer a need to set up network addresses or permissions as in many other network. More prevalent applications of Bluetooth include: Wireless control of and communication between a mobile phone and a hands-free headset. This was one of the earliest applications to become popular. Wireless networking between PCs in a confined space and where little bandwidth is required. Wireless communications with PC input and output devices, the most common being the mouse, keyboard and printer. Replacement of traditional wired serial communications in test equipment, GPS receivers, medical equipment, bar code scanners, and traffic control devices. For controls where infrared was traditionally used. Sending small advertisements from Bluetooth enabled advertising hoardings to other, discoverable, Bluetooth devices. Future of Bluetooth: * Broadcast Channel: enables Bluetooth information points. This will drive the adoption of Bluetooth into mobile phones, and enable advertising models based around users pulling information from the information points, and not based around the object push model that is used in a limited way today. Topology Management: enables the automatic configuration of the piconet topologies especially in scatternet situations that are becoming more common today. This should all be invisible to the users of the technology, while also making the technology just work. * Alternate MAC PHY: enables the use of alternative MAC and PHYs for transporting Bluetooth profile data. The Bluetooth Radio will still be used for device discovery, initial connection and profile configuration, however when lots of data needs to be sent, the high speed alternate MAC PHYs will be used to transport the data. This means that the proven low power connection models of Bluetooth are used when the system is idle, and the low power per bit radios are used when lots of data needs to be sent. * QoS improvements: enable audio and video data to be transmitted at a higher quality, especially when best effort traffic is being transmitted in the same piconet. Figure: -A typical Bluetooth USB dongle * 3-G Mobile: 2. 54 3 G falls into the category of broadband access. 2. 5G- GSM (EDGE/GPRS), CDMA 3G-VMTS/WCDMA, CDMA, speed achieved by 3G is 384K(M),2048K(S) Technology| 3G| Frequency Band| 1. 8-2. 5 GHz| Bandwidth| 5-20 MHz| Data Rate| Up-to 2 Mbps| Access| W-CDMA| FEC| Turbo-Codes| Switching| Cirsuit/Packet| Figure: -3G Services * Wi-Fi: A Wi-Fi enabled device such as a PC, game console, cell phone, MP3 player or PDA can connect to the Internet when within range of a wireless network connected to the Internet. The coverage of one or more interconnected access points — called a hotspot — can comprise an area as small as a single room with wireless-opaque walls or as large as many square miles covered by overlapping access points. Wi-Fi technology has served to set up mesh networks, for example, in London. Both architectures can operate in community networks. In addition to restricted use in homes and offices, Wi-Fi can make access publicly available at Wi-Fi hotspots provided either free of charge or to subscribers to various providers. Wi-Fi also allows connectivity in peer-to-peer (wireless ad-hoc network) mode, which enables devices to connect directly with each other. This connectivity mode can prove useful in consumer electronics and gaming applications. Figure : -A keychain size Wi-Fi detector. Operational advantages: Wi-Fi allows LANs (Local Area Networks) to be deployed without cabling for client devices, typically reducing the costs of network deployment and expansion. Spaces where cables cannot be run, such as outdoor areas and historical buildings, can host wireless LANs. * WiMAX WiMAX, an approximate acronym of Worldwide Interoperability for Microwave Access, is a telecommunications technology that provides for the wireless transmission of data using a variety of transmission modes, from point-to-point links to full mobile cellular-type access. The technology provides upto 70 Mb/sec symmetric broadband speed without the need for cables. The technology is based on the IEEE 802. 16 standard (also called WirelessMAN). The name WiMAX was created by the WiMAX Forum, which was formed in June 2001 to promote conformity and interoperability of the standard. Uses: The bandwidth and range of WiMAX make it suitable for the following potential applications: * Connecting Wi-Fi hotspots to the Internet. * Providing a wireless alternative to cable and DSL for last mile broadband access. * Providing data and telecommunications services. Providing a source of Internet connectivity as part of a business continuity plan. That is, if a business has a fixed and a wireless Internet connection, especially from unrelated providers, they are unlikely to be affected by the same service outage. * Providing portable connectivity. Comparison with Wi-Fi: Comparisons and confusion between WiMAX and Wi-Fi are frequent, possibly because both begin with the same two letters, are based upon IEEE standards beginning with 802. , and are related to wireless connectivity and Internet access. However, the two standards are aimed at different applications. WiMAX is a long-range system, covering many miles/kilometers that typically uses licensed spectrum (although it is possible to use unlicensed spectrum) to deliver a point-to-point connection to the Internet from an ISP to an end user. Different 802. 16 standards provide different types of access, from mobile (similar to a cellphone) to fixed (an alternative to wired access, where the end users wireless termination point is fixed in location. ) * Wi-Fi is generally a shorter range system, typically tens of yards/meters, though its range can be extended to over a kilometer using directional antennas. Wi-Fi uses unlicensed spectrum to provide access to a network. Typically Wi-Fi is used by an end user to access his/her own network, which may or may not be connected to the Internet. If WiMAX provides services analogous to a cellphone, Wi-Fi is similar to a cordless phone. * WiMAX and Wi-Fi have quite different Quality of Service (QoS) mechanisms. WiMAX uses a mechanism based on connections between the Base Station and the user device. Each connection is based on specific scheduling algorithms, which means that QoS parameters can be guaranteed for each flow. Wi-Fi has introduced a QoS mechanism similar to fixed Ethernet, where packets can receive different priorities based on their tags. This means that QoS is relative between packets/flows, as opposed to guaranteed. * WiMAX is highly scalable from what are called femto-scale remote stations to multi-sector maxi scale base that handle complex tasks of management and mobile handoff functions and include MIMO-AAS smart antenna subsystems. * LMDS: Local Multipoint Distribution Services (LMDS) is a radio-based access system. A fixed base-antenna (typically on a high building or tower) called Hub, services a number of users, which are also fixed. (Customer antenna on top of building). The access has a broadband capacity it can be used for all kinds of telecom services: * POTS or ISDN telephony. * Data services such as LAN interconnect, ATM, IP networks, etc. * Digital Video broadcasting. And potential customers are: * Businesses * Schools, Libraries, Health care providers * Residential consumers Each Hub is at the center of cell, a few kilometers in size, containing hundreds or thousands of users. Interconnections between hubs are typically done through fiber-optic core networks. The radio frequencies used are in the range 28 GHz to 42 GHz. This requires line-of-sight between hub and end-user. The word Local in LMDS refers to the relative short distance, or small cell-size. The words Multipoint Distribution refers to the point to multipoint nature. Figure 36: Local Multipoint Distribution Services * Free Space Optics (FSO): It is optical wireless, point-to-point line of sight broadband technology that is an alternative to fiber optic cable systems. It can transmit up to 1. 25 Gbps at a distance of 4 miles. * Satellite: It offers two-way Internet access via satellite orbiting the earth about 22000 miles above equator. PC through a special satellite modem broadcasts the requests to the satellite dish located on top of the roof / building which in turn transmits receives signal from the satellites. But it is slower in uplink as well as in downlink. BIBLIOGRAPHY (1) www. bsnl. co. in (2) www. wikipedia. org (3) www. howstuffworks. com (4) www. esnips. com

Single Variable Equations on SAT Math Complete Strategies

Single Variable Equations on SAT Math Complete Strategies SAT / ACT Prep Online Guides and Tips In a way, single variable equations are some of the most common and least common types of questions on the SAT math section. Why? Because it’s rare to find more than one or two single variable equations per test, and yet knowing how to solve and manipulate single variable equations is a basic requirement for solving most all SAT math questions. Even though you won’t often see single variable equations by themselves, it is crucial that you know how to set up, use, and manipulate them. You cannot solve the more complex expressions like quadratics, multiple variables, and so on, without first understanding single variable equations. This guide will be your complete walk-through of single variable equations for the SATwhat they are, how you’ll see them on the test, and how to set up and solve them. Once you get the hang of single variable equations, you can go on to solve more and more complex problems. What Are Single Variable Equations? A single variable equation is comprised of two parts: the (lone) variable and the equation. So let’s look at what those are and how to put them together. A variable is a symbolic placeholder for a number we do not yet know. Often, you’ll see x or y used as a variable in math problems, but variables can be represented by any symbol or letter. $$4t=20$$ In this case, t is our variable. It represents a number that is currently unknown. An equation sets two (or more) mathematical expressions equal to one another. To show that the expressions are equal, we use an equals sign (=). Each side of the expression can be as simple as a single integer or as complex as an expression with multiple variables, exponents, or anything else. $$15(a+b^3)−(a−3)^12=22$$ The above is an example of an equation. Each side of the expression equals the other. So if we put together our definitions, we know that: A single variable equation is an equation in which there is only one variable. The variable can be used multiple times and/or used on either side of the equation as long as the variable remains the same. Some examples of single variable equations: $${4(a−3)}/a=2(a^8)$$ $$a+7−(a+3)=4$$ $$6a+a−3=a+21$$ You’ll notice that some of the equations used the variable, a, multiple times. Other equations used the variable on either side of the equals sign. No matter how many times the variable is used, all of these are still single variable problems because the variable remains constant and there are no other variables. Once you find your variable, you can solve the whole puzzle. Typical Single Variable Equations on the SAT Single variable equations will fall into two broad categories on the SATgiven equations and word problems. Word problems are by far the more common and you should expect to see one or two per test. Given equations, when they appear, will usually fall between problems 1-4 on any given math section. Let’s look at each type. Given Equations A given equation will provide you with the equation you need to use to solve the problem. We will go through the exact processes needed to solve this kind of problem in the next section, but for now just understand that your goal is to isolate your variable. (We will walk through how to solve this question later in the guide) In this problem, you are being asked to find the isolated variable as your final answer. But do be sure to note that this is not always the case. Sometimes the question will ask you to solve for y alone (or x or any other variable), and sometimes the question will ask you to solve for y to a different term (2y or 12y, etc.). Always pay close attention to exactly what the question is asking you to find. You need to first isolate your variable to solve the problem, but always double-check whether you should stop there or if you need to continue on, in order to find your final answer. Word Problems A word problem will describe a situation and ask you to find a missing variable. You must write your own equation based on the information you are given in the question. Again, your final answer may be the value of your variable (x or y, etc.) or your variable taken to a different term ($2x$, $y^2$, etc.). (We will walk through how to solve this question later in the guide) How to Manipulate a Single Variable Equation In order to solve a single variable equation, we must isolate our variable on one side of the equation. And the way we do this is by shifting everything else to the other side of the equals sign. In order to shift our terms (expressions), we must cancel them out on their original side. This means we have to set the non-variablesto zero when using addition/multiplication, and set the variable to 1 when using division/multiplication. (Why do we set it to 1 when using division/multiplication? Because we use multiplication and division to isolate our variable. But setting it to 1, we give ourselves just the one variable to work with.) The way we cancel out our terms is by performing the opposite function of each term. Opposite function pairs are: Addition and subtraction Multiplication and division For example, if we have a term on one side that has a minus sign (subtraction), we must add that same amount from both sides. $x−4=6$ $x−4+4=6+4$ $x=10$ If we have a term that is being multiplied, we must divide that same amount from both sides. $4x=20$ ${4x}/4={20}/4$ $x=5$ And so on. Whatever you do on one side of the equation, you must do on the other. This cancels out like terms and essentially moves your terms from one side of the equation to the other. Manipulating equations isall about balance. Steps to Solving a Single Variable Problem Let us take a typical variable expression and break it into the steps needed to solve it. $14−2x+2+6x=64.$ Find ${1/2}x.$ #1: Combine like terms If there is more than one term with a same variable, we must combine them in order to ultimately isolate that variable. We can add or subtract terms with a same variable in the same way we can any other numbers. $14−2x+2+6x=64$ Here we have a $−2x$ and a $6x$ (notice how we had to keep the signs in front of the numbers intact). Now we add them together. $−2x+6x=4x$ We also have multiple numbers without variables on the left side of our equation. We must combine these as well, as they are also like terms. $14+2=16$ So now, when we put the pieces together, our equation looks like this: $16+4x=64$ #2: Isolate the term with your variable Once we have combined our variables, we must isolate the variable term. If the term is simply the variable itself (e.g. $x$), then we can skip this step. But since our term here is $6x$, we must isolate the whole term first. $16+4x=64$ We have a positive 16 here that we want to get rid of in order to isolate our $4x$. This means we must subtract 16 from both sides of our equation. Why? Because we have a positive 16, which means that it is addition. And subtraction is the opposite of addition. We must also subtract 16 from either side to cancel out the 16 on the first expression (make it zero) so that we can isolate our variable. $16−16+4x=64−16$ $4x=48$ #3: Isolate your variable Now that we’ve isolated our term ($4x$), we can further isolate the variable. Again, we perform an opposite function of the term. In this case, we have $4x$, which uses multiplication. In order to isolate the variable, we must therefore use division (the opposite of multiplication) by dividing by 4 on both sides. This will set our x equal to one and thus isolate it. $4x=48$ ${4x}/4={48}/4$ $x=12$ #4: Double-check your variable by plugging it back in Now that we’ve solved for our variable, let us check to make sure it is correct by plugging it back into the original equation. $x=12$ $14−2x+2+6x=64$ $14−2(12)+2+6(12)=64$ $14−24+2+72=64$ $−10+74=64$ $64=64$ Success! We have correctly isolated the variable and found its value. #5: And, finally, double-check to make sure you are answering the right question. Ah-ha! We can’t stop here. Our initial question asked for the value of $1/2x$, not just x by itself. If we had stopped here at $x=12$, we would have gotten the final answer wrong. Now, we end the problem by saying: ${1/2}x=(1/2)12=6$ So our final answer is 6. Always be sure to double-check both that your variable is correct and that you are answering the exact question the test is asking you to answer. Now let’s try it again with our given equation problem from earlier. We have ${1/3}y+9=0$ and we must isolate our variable in order to ultimately find the value of y Step 1, combine like terms: There are no like terms to combine, so we can skip step 1. Step 2, isolate the variable term: $1/3y+9=0$ $1/3y+9−9=0−9$ $1/3y=−9$ Step 3, isolate the variable: $1/3y=−9$ $3*1/3y=−9$ $y=−27$ Step 4, double-check answer: $1/3y+9=0$ $(1/3*−27)+9=0$ $−9+9=0$ $0=0$ Step 5, double-check if answering the right question: The initial question wanted us to find y, and that is exactly what we found. We can confidently say that we are finished. Success! Our final answer is A, -27. Ready to put your single variable equation knowledge to the test? Test Your Knowledge 1. 2. 3. 4. Answers:700, B, A, C Answer Explanations: 1. This problem is one to be cautious of because you'll note that your final answer is NOT your variable. Why? Because we are asked to find the total amount of money each person made during the week and yet our variable is the amount of sales they made. So let's walk through the problem and set up our equation. We are told that both Tom and Alison made the same amount of money in a certain week, which means that this is an equation problem (their earnings are set equal to one another). We also know they had the exact same number of sales and that this number is yet unknown. This is our single variable. Let us call it x. Tom made 300 dollars plus 20% of his sales. We can set up his half of the equation like so: $300+0.2x$ (For more on percentages and why we can set up 20% of x as $0.2x$, check out our guide to SAT fractions and ratios.) Alison made 200 dollars plus 25% of her sales. So we can set up her half of the equation thusly: $200+0.25x$ Now, let us set the two sides equal to one another and solve for our variable. $300+0.2x=200+0.25x$ First, let us combine our like terms by moving them to opposite sides of the equation: $300−200=0.25x−0.2x$ $100=0.05x$ Now, let's isolate our variable: $100/0.05={0.05x}/0.05$ $2000=x$ This means that they each sold 2000 dollars worth of product. But wait! We can't stop here. The question asked us to find their weekly compensation, NOT their weekly sales. We must plug 2000 back into one of the original equations in place of x to find our final answer. Let's take Tom's weekly earnings again: $300+0.2x$ $300+0.2(2000)$ $300+400$ 700 So both Tom and Alison (remember, they made the same amount) earned 700 dollars that week. Our final answer is 700. (Note: you can also double-check your answer with Alison's original equation as well: $200+0.25x$ $200+0.25(2000)$ $200+500$ 700 Either way, the answer is 700) 2. We are told that a triangle has a perimeter of 13 and one side length of 3. The other two sides are equal. That means we would set up an equation that would look like this: $3+2x=13$ The left side of the equation is the sum of all the triangle’s sides. x is substituting for our unknown side lengths. And we have multiplied our x by 2 because the two unknown side lengths are equal. Now, we solve. $3+2x=13$ Subtract 3 from both sides $3−3+2x=13−3$ $2x=10$ Isolate our variable ${2x}/2=10/2$ $x=5$ So each of the other side lengths must be equal to 5. Let’s plug the answer back in to make sure this is correct. $3+5+5=13$ $13=13$ Success! And we are being asked for the length of each side, so we know that our variable answer is the final solution. Our final answer is B, 5. 3. We are being asked to find the number of sandwiches that Ali made, so let’s make our unknown variable a for Ali. This means that Ali made a number of sandwiches. We are told that Ben made three times as many sandwiches as Ali, which means that Ben made $3a$ sandwiches. Now Carla made twice as many sandwiches as Ben. We will still say that all the sandwiches made are in terms of a number of sandwiches, so Carla made $2*3a=6a$ sandwiches. And we also know that the total number of sandwiches was 20. So now, when we put it all together, we get: $a+3a+6a=20$ Combine our like terms and we get: $10a=20$ Isolate our variable. ${10a}/10={20}/10$ $a=2$ Now let’s double-check to make sure that is correct. If Ali makes 2 sandwiches, and Ben makes three times as many, he will have made 6 sandwiches. If Carla makes twice as many as Ben, she’ll have made 12 sandwiches. $2+6+12=20$ 20=20 Success! We have correctly isolated our variable. Since we said that a was the number of sandwiches that Ali made, this means: Our final answer is A, Ali made 2 sandwiches. 4. We are given the problem: "$10+x$ is 5 more than 10." The "is" in the question sets the terms equal, so when we translate this statement, we get: $10+x=15$ Now, let’s isolate our variable. $10−10+x=15−10$ $x=5$ Now let’s double-check by plugging our x back into the original equation. $10+x$ is 5 more than 10. $10+5=15$ is 5 more than 10. Success, we have isolated our variable. But wait! The final question wants us to find the value of 2x, not just x. $x=5$ $2(5)=10$ So our final answer is C, $2x=10$ Whoo! You conquered those single variable equations! The Take Aways Single variations make up the backbone of many other SAT problems. By knowing how to manipulate these kinds of expressions, you’ll be able to build on these techniques to solve much more complex problems and equations. Just remember to always perform the same act to each side of the equation and save isolating your variable for last, and you’ll be conquering single variable equations left and right. Now you’ve got the building blocks for understanding how to go forth and take on the rest of the SAT math topics. So build upon this knowledge and tackle the rest of what SAT math has to offer. What’s Next? You’ve build up your mathematical foundation and now you’re raring to take on more. Before you start in on another SAT math topic guide, make sure you have a good idea of all the topics covered on the SAT math. Think you might need a tutor? Check out the best ways to find a tutor that suits your needs, whether online or in person. Taken a practice test and don’t know how you match up for schools? Make sure you have a good idea of what your ideal score truly is. And if you feel like you’ve got a handle on the math itself, but struggle with the timing, then be sure to check out our guide on how to complete your SAT math section on time. Want to improve your SAT score by 160 points? Check out our best-in-class online SAT prep program. We guarantee your money back if you don't improve your SAT score by 160 points or more. Our program is entirely online, and it customizes what you study to your strengths and weaknesses. If you liked this Math strategy guide, you'll love our program.Along with more detailed lessons, you'll get thousands ofpractice problems organized by individual skills so you learn most effectively. We'll also give you a step-by-step program to follow so you'll never be confused about what to study next. Check out our 5-day free trial:

Democratization and Reversal Democracy Term Paper

Democratization and Reversal Democracy - Term Paper Example The exploration of the internet services coupled with other social sites like twitter, face book and internet related ways of disseminating information have been known to enhance the scope of participation and contribution on issues that directly attract the public debate (Diamond 35). The contribution of the liberal technology in enhancing democratization is coming with a couple of threats to the existing regime. The regimes are also hell-bent in cushioning themselves from the looming exposure of the actions that are perceived to be rolling back the democratic processes gained in the country. In this regard, most of the totalitarian regimes have opted to censor media houses and as well as the internet providers that enables the citizen to participate in the discussion the reprimands the government conduct on abuse some fundamental human rights (Diamond 43). The media operators have also been in the same trouble with the regimes they serve under following their efforts to expose the unorthodox ways of handling issues. Technological liberation has also enabled the public to not only scrutinize the government conduct but also increased the amount of participation on issues of public interest. The contribution of the technology in democratization in this regard can not be underestimated as a key player in the democratization process (Diamond 32). The role of liberal technology has attracted the concern of the optimist and the pessimists in equal measure. The optimists of the liberal technology views it as a way of empowering the individuals, instituting a strong and viable civil society that is able to agitate and champion for the rights of the people and reach a critical mass of individuals in the shortest time possible. The technology will also facilitate utmost independent communication and mobilization (Diamond 55). On the other side, the pessimist of the liberal technology have a contrary view, they cite china as one of the countries that heavily explore the use of technology as having not realized any significant change in the political arena. The Chinese Communist Party has continued ruling with iron fist and has firmly shielded external intrusion as it is beyond what accountability means (Diamond 61). Liberal technology has been defined as the variety of information and communication technology that has the ability to enhance the social, economic, and political freedom. In this sense, the technology facilitates on the way news are reported, exposure of the wrongdoings in the country, enables quick and most efficient ways of opinion expression, mobilization of the protest, close monitoring of the elections to ensure they are free and fair (Diamond 68). In addition to all these, the initiative also facilitates scrutiny of the government, entrench deep public participation and most importantly enhance and expand the horizons that come with freedom. Malaysia is one of the countries that have the record of consistently controlling the ope ration of the technological flow of information as they deem it a factor that is detrimental to the existence of the government. The utilization of the technology has also been on the rise as in the records of the recent statistics. Liberal technology has a convincing history in the revolutionary world, the effect of technology in the dissemination and perception changes can be