The gsm network operates in the frequency spectrum of 850mhz and. The preferred technology for thirdgeneration systems depends. Gsm technology global system for mobile communication or groupe special mobile to standardize cellular communication thoughout europe. Its no secret that mobile network providers are sunsetting code division multiple access cdma. Sep 27, 2019 the cellular mobile service is being used everywhere in the world today. Individual conversations are encoded with the help of pseudorandom digital sequence. Gsm operates on the 900 mhz, 1800 mhz and 1900 mhz. The generation is generally utilized in ultraexcessivefrequency uhf cellular smartphone systems, bands ranging among the 800mhz and 1. Cdma technology in cdma tutorial 03 april 2020 learn. The technology of cdma was used in 1957, when the young military radio engineer leonid. Scribd is the worlds largest social reading and publishing site.
A system can be configured so that the improvements in terms of speech encoder and bit rate reduction may be easily incorporated. Cdma uses spreadspectrum technology to minimize the problems. Although all users are transmitting in the same rf band, individual users are separated from each other via the use of orthogonal codes. More security is provided in cdma technology as compared with the gsm technology as encryption is inbuilt in the cdma system and this technology uses the spread spectrum signal. Gsm and cdma are competing wireless technologies with gsm enjoying about an 82% market share globally. Code division multiple access cdma is a multiple access technique where different users. Incremental progress 1g amps data capabilities 30 khz. Jan 09, 2015 sumit thakur mechanical gsm seminar and ppt with pdf report. There are some disadvantages of cdma code division multiple access are given below, the system is more complicated. It has gained widespread international acceptance by cellular radio system operators as an upgrade that will dramatically increase both their system capacity and the service quality. When they both are used together, they will be termed as 3g cdma.
Fdma technology frequency division multiple access fdma is one of the most common analogue multiple access methods. Cellular technology enables mobile communication because they use of a complex two way radio system between the mobile unit and the wireless network. Future wireless communication systems should be operating mainly, if not completely, on burst data services carrying multimedia traffic. On the other hand, in cdma the network identifies a handset by the information stored in the internal memory and hence, its handset specific. Gsm seminar and ppt with pdf report global system for mobile communication. Cdma benefits increased voice capacity by several times provided more efficient use of spectrum resources increased battery life in mobile devices better security with cdma encoding cdma is the foundation for mobile 3g technologies potential voice capacity improvements1 reference 1x 3x 14x analog 1980s gsm 1990s cdmaone 1990s. Cdma technology for intelligent transportation systems. Long term evolution lte is a mobile network technology that is being deployed by mobile operators on both the gsm and the cdma technology paths. Cdma technology is known as a spreadspectrum technique which allows many users to occupy the same time and frequency allocations in a given band and space.
Fitzek04 february 2003lecture 2the following text is. Pdf code division multiple access cdma system in multipath. The receiver must recognize the frequencyversustime function employed by the transmitter. Code division multiple access cdma the concept of signal spreading and its uses in communications lets take a stright forward binary signal of symbol rate 2. The first generation cdma technology has been used in both 2g and 3g mobile cellular. Short message service center or smsc the node that stores and forwards short messages to and from the. The family of is95 cdma technologies cdmaone describes a complete wireless system based on the tiaeia is95 cdma standard, including is95a and is95b revisions. Using spreadspectrum technology allows for the signals to be transmitted over a wide spectrum of the electromagnetic spectrum. Phil flikkemas usf briefing introduction to spread spectrum pdf about the capacity of a ds spread spectrum cdma cellular system pdf overview of modulation techniques for wireless pdf prof. The entire information about the user and the account is stored in the internal memory of the device or handset. Wideband cdma radio transmission technology the university. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext.
To permit this without undue interference between the users, cdma. Cdma established the foundation for 3g technologies is95 cdmaone initial cdma standard from qualcomm may 1995 mobile 3g evolved into two competing standards both based on cdma cdma2000 uses 1. Signals can be detected as the gsm signals are concentrated in the narrow bandwidth. Fitzek universita di ferraracode division multiple accessfrank h. The next generation cdma technologies wiley online books. When the fcc issued 1900 mhz to pcs in the united states it was based on gsm.
Cdma is actually a newer technology than gsm and it offers some of the newest calling and data options evdo rev. For cdma spreading code, we need a random sequence that passes certain quality criterion for randomness. Enhanced services can be provided to cdma one subscribers through cdma2000. It allows each user to transfer over the entire frequency spectrum all the time. This technology was used as a military technology for first time in the world war ii by the english associates to break the german attempts of jamming transmissions. Gsm technology was developed by europe in1982 but its massive deployment started in 1992. Cdma technology is used in commercial cellular communications to make better use of radio spectrum when compare to other technologies. Code division multiple access cdma is a channel access method utilized by various radio communication technologies. Codedivision multiple access cdma is a channel access method used by various radio. This is achieved by a specific but complex mathematical function.
Cdma technology free download as powerpoint presentation. The cdma based digital radar technology will give rise to. Nov 24, 2019 cdma, which stands for code division multiple access, is a competing cell phone service technology to gsm, the worlds most widely used cell phone standard. Cdma, which stands for code division multiple access, is a competing cell phone service technology to gsm, the worlds most widely used cell phone standard. Cdma has faster data rate as compared to gsm as evdo data transfer technology is used in cdma which offers a maximum download speed of 2 mbps. Pdf many digital cellular and mobile systems are in use today. The signal cannot be detected easily in cdma as compared to the signals of gsm, which are concentrated in the narrow bandwidth. Cdma technology for intelligent transportation systems arxiv. In order to develop a global system, a forum was created. The cdma is based on spread spectrum technology which makes the optimal use of available bandwidth.
On 7 november 1989, qualcomm publicly demonstrated a digital cellular radio system based on code division multiple access cdma spread spectrum technology, which increased capacity, improved service quality, and. Cdma technology has given significant advantages over other parallel technologies in terms of spectrum efficiency and overall performance. This technology makes optimal use of available bandwidth and is based on spread spectrum technology. Gsm and cdma are two dominant technologies in the world of mobile communication. The development of code division multiple access cdma enabled thirdgeneration 3g mobile system is.
The heart of such cdma technology is the spread spectrum technology using pn sequence coding. The gateway msc or gmsc the purpose of which is to query the hlr and determine the location of the subscriber. Cdma code division multiple access or cdma has its roots in wwii era spread spectrum technology. Using references from previous research on cellular telecommunications, the introduction of cdma and gsm technologies to aspects of technology, networking and security.
Communication and cdma code division multiple access. Cdma gives the user entire spectrum all of the time. Technically gsm global system for mobile communications, originally from groupe special mobile. Cdma, code division multiple access an implementation of direct sequence spread spectrum, dsss, and was used almost universally for 3g mobile communications standards as it provided an excellent format as a multiple access scheme. The paper presents cdma from a dual point of view, as a powerful technology for the most dynamic communications networks, cellphone broadband mobile. Gsm uses a variation of time division multiple access and is the most widely used of the three digital wireless telephony technologies. As such it gave a significant step forwards over the tdma fdma schemes used for 2g, enabling data transmission in a way that had not been previously possible. Tdma time division multiple access and cdma code division multiple access. Pdf cdma technology for intelligent transportation systems. Whereas, cdma stands for code division multiple access. Gsm global system for mobile communication is a digital mobile network that is widely used by mobile phone users in europe and other parts of the world. The core principle of spread spectrum is the use of noiselike carrier waves, and, as the name implies, bandwidths. This protocol uses cdma access to send voice and data and signals between mobile phones and cell sites. Since the transmission is continuous, less number of bits are required for synchronization and framing.
The international telecommunications union itu is also considering wcdma technology for a global standard imt2000. Aug 18, 2019 cdma technology filetype pdf wide band cdma technology is selected for utran air interface. Cdma technology broadcast engineering electronic engineering. We want equal number of two 0s and 1s, a length of three 0s and 1s and four 0s and 1s etc. Code division multiple access cdma is a sort of multiplexing that facilitates various signals to occupy a single transmission channel. Code division multiple access cdma is a digital technique for sharing the frequency spectrum. The gsm operates on the wedge spectrum called a carrier. Difference between gsm and cdma with comparison chart. Sep 27, 2016 the basic difference between gsm and cdma is that the gsm is a sim specific i. The development of the cdma technique dates back to the. Pdf next generation cdma technology irfan ali khan. Fitzek04 february 2003lecture 2the following text is taken partially from my phd thesis. Code division multiple access 2000 cdma2000 is a third generation 3g standard developed by the international telecommunication union itu.
Cdma is known to be an outdated technology largely due to networks global reach issue but it is not so. The first generation cdma technology has been used in both 2g and 3g mobile cellular standards and it. Mobile device investigations program technical operations. Cdma i about the tutorial code division multiple access cdma is a channel access method normally used by 3g radio communication technology as well as in some other technologies. Basics idea about cdma technology and its applications. After the war ended, qualcomm patented the technology and made it commercially available as a digital cellular technology. Youve probably heard of these acronyms when you were told that you cant use a certain phone on your mobile network because theyre using different. What is gsm global system for mobile communication.
Gsm standard still evolving and improved with new features and services. There are two types of spreadspectrum technologies. The need to support highspeed burst traffic has already posed a great challenge to all currently available airlink technologies based either on tdma or cdma. Thus, in this type of cdma intracellular interference is avoided. Base stations are referred to as nodeb and control equipment for. Flexibility gsm is more flexible than cdma as wide range of phones can be used with this service. Jul 20, 2007 future wireless communication systems should be operating mainly, if not completely, on burst data services carrying multimedia traffic. Gsm uses digital communication system or dcs 1800 and is the worlds main 2g standard. Depending on the spectrum available, live lte networks can deliver very fast data speeds of up to 100mbps in the downlink and 50mbps in the uplink. Cdma can be implemented in several ways, two of which are frequency hopping and direct sequencing. Dcs 1900 is considered the gsm standard for north america and is called north american gsm. What does the cdma phaseout mean for my companys iot strategy in the longterm.
Cdma technology was developed and patented by qualcomm, a famous chip maker. Codedivision multiple access cdma is a channel access method used by various radio communication technologies. Sumit thakur mechanical gsm seminar and ppt with pdf report. Code division multiple access cdma the telecom generations. Cdma technology filetype pdf wide band cdma technology is selected for utran air interface. Gsm is in use by 76% of users as compared to cdma which is in use by 24% users. As the number of users increases, the overall quality of services decreases. This is done in gsm via gaussian minimum shift keying gmsk. This allows several users to share a band of frequencies see bandwidth. Evdo ready mobile phones are required to use this technology.
Analog cellular systems use frequency division multiple access fdma technique find. It is proprietary in nature, which has resulted in the technology not being adopted globally in the manner in which gsm has seen. The frequency band is divided into channels of equal bandw. Multiple users are assigned radio resources using spread spectrum techniques. In second and third generation wireless communication a protocol named cdma came into existence. In 2000, gsm become very popular technology worldwide. However, the main focus is to differentiate between 3g and cdma. But the big question on the minds of engineers, manufacturers, and anyone else involved in iot is. These two technologies differ in the way calls and data travel over the mobile phone networks. On 7 november 1989, qualcomm publicly demonstrated a digital cellular radio system based on code division multiple access cdma spread spectrum technology, which increased capacity, improved service quality, and extended battery life. It uses radio frequencies radio channels over and over again throughout a market with minimal interference, to serve a large number of simultaneous conversations. Introduction to cdma code division multiple access cdma is a radically new concept in wireless communications. The technology is commonly used in ultrahighfrequency uhf cellular telephone systems, bands ranging between the 800mhz and 1. These two technologies differ the way in which the calls and data transfer takes place over a network and mobile.
Cdma is a wireless transmission technology that was developed during world war ii by the english allies to avoid having their transmissions jammed. Cdma code division multiple access is a technology that forms the basis of 3g mobile phones. Youve probably heard of these acronyms when you were told that you cant use a certain phone on your mobile network because theyre using different technologies that are not compatible. Therefore, the bandwidth efficiency of a communication technology will be a. In 1985, the fcc allocated three frequency bands to spread spectrum communications. Guard band and guard time both are required to be provided. It stands for code division multiple access and is used for the standards of 3g that include cdma2000 and wcdma.
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