Cellular networks


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Cellular networks

  2. 2. HISTORY OF MOBILE PHONES Two-way radios (known as mobile rigs) were used in vehicle. During the early 1940s, Motorola developed a backpacked two-way radio, the Walkie-Talkie and later developed a large hand-held two-way radio for the US military. This battery powered "Handie- Talkie" (HT) was about the size of a mans forearm. Later radio telephony was introduced on a large scale in German tanks during the Second World War.
  3. 3. EARLY YEARS.. In 1910 Lars Magnus Ericsson installed a telephone in his car, although this was not a radio telephone. While travelling across the country, he would stop at a place where telephone lines were accessible and using a pair of long electric wires he could connect to the national telephone network. 1946 soviet engineers G. Shapiro and I. Zaharchenko successfully tested their version of a radio mobile phone mounted inside a car. The device could connect to local telephone network on a range up to 20 kilometers. Contd… Contd…
  4. 4. EARLY YEARS.. In1945 The first mobile-radio-telephone service is established in St. Louis, Miss. The system is comprised of six channels that add up to 150 MHz. The project is approved by the FCC, but due to massive interference, the equipment barely works. In 1947 AT&T comes out with the first radio-car-phones that can be used only on the highway between New York and Boston; they are known as push-to-talk phones. The system operates at frequencies of about 35 to 44 MHz, but once again there is a massive amount of interference in the system. AT&T declares the project a failure. 4
  5. 5. EARLY YEARS…. In 1973 Dr. Martin Cooper invents the first personal handset while working for Motorola. He takes his new invention, the Motorola Dyna-Tac., to New York City and shows it to the public. His is credited with being the first person to make a call on a portable mobile-phone.
  6. 6. EARLY YEARS……. Dr. Martin Cooper of Motorola made Motorola, the first US analogue mobile phone call on a Top of cellular larger prototype telephone tower model in 1973.
  7. 7. PICTURE GALLRY The First Mobile Phone: Motorola DynaTAC 8000X (1983) Motorolas DynaTAC 8000X wasnt commercially available until 1983, but its beginnings can be tracked back to 1973 when the company showed off a prototype of what would become the worlds first mobile phone. The DynaTAC weighed almost a kilogram, provided one hour of battery life and stored 30 phone numbers in its phonebook. The Motorola DynaTAC is best known for bring used in the 1987 movie Wall Street, starring Michael Douglas as corporate raider Gordon Gecko.
  8. 8. PICTURE First Car Phone: Nokia Mobira Senator (1982) In the early 1980s, the mobile phone was best known for its in-car use. Nokias Mobira Senator, released in 1982, was the first of its kind. A car phone that weighed almost 10 kilograms, the Nokia Mobira Senator resembled a large radio rather than a conventional mobile phone.
  9. 9. FIRST GSM PHONE: NOKIA 101 (1992) First GSM Phone: Nokia 101 (1992) Nokias 101 was the worlds first commercially available GSM mobile phone. Paving the way for future "candy- bar" designs, the 101 had a monochrome display, an extendable antenna and a phonebook that could store 99 phone numbers. It did however lack Nokias famous "Nokia tune" ringtone — this wasnt introduced until the next model in 1994.
  10. 10. EARLY YEARS…. In 1981 The FCC makes firm rules about the growing cell phone industry in dealing with manufactures. It finally rules that Western Electric can manufacture products for both cellular and terminal use. (Basically they admit that they put the phone companies about 7 years behind) In 1988 One of the most important years in cell phone evolution. The Cellular Technology Industry Association is created and helps to make the industry into an empire. One of its biggest contributions is when it helped create TDMA phone technology, the most evolved cell phone yet. It becomes available to the public in 1991. 10
  11. 11. TOUCH SCREEN: IBM SIMON PERSONALCOMMUNICATOR (1993) Touch Screen: IBM Simon Personal Communicator (1993) The IBM Simon Personal Communicator was one of the first attempts at a commercially viable smartphone. A joint venture between IBM and Bellsouth, the Simon was only sold into the US and was best known for having no physical keys. It used a touch screen and optional stylus to perform the majority of its functions, which included dialling phone numbers, sending faxes and writing memos. It was priced at $899 when it launched.
  13. 13. INTRODUCTION OF MOBILE TECHNOLOGY First Generation (1G) Analog system designed for voice only communication. 1G systems are almost extinct now, Second Generation (2G) Use GSM and IS-95 CDMA technologies CDMA Allows users to communicate with different codes Still designed for voice communication 13
  14. 14. INTRODUCTION OF MOBILE TECHNOLOGY 2.5 and 2.75 Generation General Packet Radio Service(GPRS )and CDMA2000 (Phase 1) are belonged to 2.5 G Enhanced Data Rates for GSM Evolution(EDGE) is belonged to 2.75G As higher data rate is provided, allows some data transmission 14
  15. 15. INTRODUCTION OF MOBILE TECHNOLOGY Third Generation (3G) Two 3G, Universal Mobile Telecommunication system(UMTS )and CDMA-2000, are used. UMTS is broadly deployed in Europe and CDMA-2000 is being deployed in North American and parts in Asia Higher data transmission rate (up to 2Mbps) which allows video conferencing 15
  16. 16. INTRODUCTION OF MOBILE TECHNOLOGY Forth Generation (4G) Combined the technologies of Wireless local area network (will be introduced soon) and 3G 16
  18. 18. BASIC CONCEPT Cellular system developed to provide mobile telephony: telephone access “anytime, anywhere.” First mobile telephone system was developed and inaugurated in the U.S. in 1945 in St. Louis, MO. This was a simplified version of the system used today.
  19. 19. SYSTEM ARCHITECTURE A base station provides coverage (communication capabilities) to users on mobile phones within its coverage area. Users outside the coverage area receive/transmit signals with too low amplitude for reliable communications. Users within the coverage area transmit and receive signals from the base station. The base station itself is connected to the wired telephone network.
  20. 20. FIRST MOBILE TELEPHONE SYSTEM One and only one high power base station with which all users communicate. NormalTelephone Entire Coverage System Area Wired connection
  21. 21. CELLULAR GEOMETRIES• The most common model used for wireless networks is uniform hexagonal shape areas – A base station with omni-directional antenna is placed in the middle of the cell d = 3R
  22. 22. PROBLEM WITH ORIGINAL DESIGN Original mobile telephone system could only support a handful of users at a time…over an entire city! With only one high power base station, users phones also needed to be able to transmit at high powers (to reliably transmit signals to the distant base station). Car phones were therefore much more feasible than handheld phones, e.g., police car phones.
  23. 23. IMPROVED DESIGN Over the next few decades, researchers at AT&T Bell Labs developed the core ideas for today’s cellular systems. Although these core ideas existed since the 60’s, it was not until the 80’s that electronic equipment became available to realize a cellular system. In the mid 80’s the first generation of cellular systems was developed and deployed.
  24. 24. THE CORE IDEA: CELLULAR CONCEPT The core idea that led to today’s system was the cellular concept. The cellular concept multiple lower-power base stations concept: that service mobile users within their coverage area and handoff users to neighboring base stations as users move. Together base stations tessellate the system coverage area.
  25. 25. CELLULAR CONCEPT Thus, instead of one base station covering an entire city, the city was broken up into cells or smaller coverage cells, areas. Each of these smaller coverage areas had its own lower- power base station. User phones in one cell communicate with the base station in that cell.
  26. 26. 3 CORE PRINCIPLES Small cells tessellate overall coverage area. Users handoff as they move from one cell to another. Frequency reuse.
  27. 27. SUMMARIZATION 1G 2G 2.5G 3G 3.5G 4GSpeeds n/a <20Kbps 30Kbps to 144Kbps to 384Kbps to 100Mbps to 90Kbps 2Mbps 14.4Mbps 1GbpsFeatures Analog Voice; SMS; MMS; Images; Full motion On-demand High- (voice only) conference Web browsing; video; video; video quality calls; caller ID; Short audio video streaming conferencing streaming PTT clips; games; music; 3D video, HQ apps; Ring tone gaming; faster video downloads Web browsing conferencin g; VOIP telephonyTechnology AMPS GSM CDMA GPRS 1xRTT UMTS 1xEV-DO HSPDA 1x-EV-DV WiMax iDen EDGETime 1980 1990 – 1995 1995 – 2000 2000 – 2005 2005 + TBA
  29. 29. WHAT IS GSM ? Global System for Mobile (GSM) is a second generation cellular standard developed to cater voice services and data delivery using digital modulation
  30. 30. GSM: HISTORY• Developed by Group Spéciale Mobile (founded 1982) which was an initiative of CEPT ( Conference of European Post and Telecommunication )• Aim : to replace the incompatible analog system• Presently the responsibility of GSM standardization resides with special mobile group under ETSI ( European telecommunication Standards Institute )• Full set of specifications phase-I became available in 1990• Under ETSI, GSM is named as “ Global System for Mobile communication “• Today many providers all over the world use GSM (more than 135 countries in Asia, Africa, Europe, Australia, America)• More than 1300 million subscribers in world and 45 million subscriber in India.
  31. 31. CODE DIVISION MULTIPLE ACCESS (CDMA) used in several wireless broadcast channels (cellular, satellite, etc) standards unique “code” assigned to each user; i.e., code set partitioning all users share same frequency, but each user has own “chipping” sequence (i.e., code) to encode data encoded signal = (original data) X (chipping sequence) decoding: inner-product of encoded signal and chipping sequence allows multiple users to “coexist” and transmit simultaneously with minimal interference (if codes are “orthogonal”) 6-31
  32. 32. CDMATHE MOST ADVANCED WIRELESSDIGITAL TECHNOLOGY 1G Analog 2G Time Division (TDMA & GSM) 3 – 7x Analog Capacity 3G Code Division .............. (CDMA2000®, WCDMA)20 – 26x Analog Capacity
  33. 33. CDMA2000 BENEFITS FOR OPERATORS,SUBSCRIBERS AND GOVERNMENTSCDMA is a high-speed wireless data and voicenetwork solution for low-cost, easy to deploy,high-performance services, that address theneeds of governments, operators andsubscribers CDMA can support high volumes of voice traffic and high-speed data traffic; Contd.
  34. 34. .Contd Instead of being limited to a narrow channel structure in a given frequency, CDMA spreads signal across 1.25 MHz of the spectrum, and simultaneously transmits unique, digitally encoded and encrypted signals over the same radio frequency (RF) carrier; CDMA2000 technology can be configured for data and/or voice, as well as for fixed or mobile services.Due to its efficient use of the spectrum to provide high-quality voice and high-speed data services, CDMA canbe utilized for fixed voice and data services, deliveringend-users the richness and variety of the Internet withthe quality and reliability of the traditional phonenetwork.
  35. 35. OFDM Divides the spectrum into a number of equally spaced tones. Each tone carries a portion of data. A kind of FDMA, but each tone is orthogonal with every other tone. Tones can overlap each other. Example: 802.11a WLAN
  36. 36. 3G WIRELESS SYSTEMS3G Wireless Systems are the new generation ofsystems that offer high bandwidth and support digitalvoice along with multimedia and global roaming.Globally, different systems are being used, so, tomigrate to globally acceptable systems, numerousstandardization activities were carried out and threesystems emerged: W-CDMA, CDMA2000, and TD-SCDMA
  37. 37. Applications Using 3GCommunication services Education•Video telephony •Virtual schools•Video conference •On-line science lab•Personal location (GPS) •On-line library •On-line language labs •Training
  38. 38. Applications Using 3G…Business services Finance services• Mobile office •Virtual banking•Narrowcast business TV •On-line billing•Virtual workgroups •Universal USIM and credit card•Expertise on tapEntertainment•Audio on demand•Games•Video clips•Virtual sightseeing
  39. 39. 3G CONCLUSION3G technologies promise to deliver a lot and areslowly being put into effect.We have already started seeing the early featuresof 3G technologies being implemented in ourphones, i.e., the video phones in the market.It remains to be seen how much of the promisedfeatures and applications are actuallyimplemented in today’s economy.However, they have been slow in coming in. Let’ssee what the future holds…