Gsm Vs Cdma


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Gsm Vs Cdma

  1. 1. Presentation on GSM Vs. CDMA – - Santoshkumar S M
  2. 2. The History GSM – During the early 1980s, analog cellular telephone systems were experiencing rapid growth in Europe, particularly in Scandinavia and the United Kingdom, but also in France and Germany. – In 1982 the Conference of European Posts and Telegraphs (CEPT). – The study group called Groupe Spécial Mobile (GSM). – First outcome of this group was a Pan-European Public Land Mobile System, which is an Analog system.
  3. 3. GSM : The History – Commercial service was started in mid-1991, and by 1993 there were 36 GSM networks in 22 countries with Ph-I Spec. of ETSI. – Earlier 1994, Over 200 GSM networks (including DCS1800 and PCS1900) are operational in 110 countries around the world. – GSM systems exist on every continent, and the acronym GSM now aptly stands for Global System for Mobile communications. This is now a Digital system. – Advancements in compression algorithms and DSPs would allow the fulfillment of the original criteria and the continual improvement of the system in terms of quality and cost.
  4. 4. GSM : The Architecture
  5. 5. GSM : The Architecture Mobile Station : – The mobile station (MS) consists of the mobile equipment (the terminal) and a smart card called the SIM. – The mobile equipment is uniquely identified by the International Mobile Equipment Identity (IMEI). The SIM card contains the International Mobile Subscriber Identity (IMSI) used to identify the subscriber to the system, a secret key for authentication, and other information. The IMEI and the IMSI are independent, thereby allowing personal mobility. The SIM card may be protected against unauthorized use by a password or personal identity number. –
  6. 6. GSM : The Architecture – Base Station Subsystem – The Base Station Subsystem is composed of two parts, the Base Transceiver Station (BTS) and the Base Station Controller (BSC). These communicate across the standardized Abis interface, allowing (as in the rest of the system) operation between components made by different suppliers. – It handles radio-channel setup, frequency hopping, and handovers, as described below. The BSC is the connection between the mobile station and the Mobile service Switching Center (MSC). – GSM systems exist on every continent, and the acronym GSM now aptly stands for Global System for Mobile communications. This is now a Digital system.
  7. 7. GSM : The Architecture – Network Subsystem – The central component of the Network Subsystem is the Mobile services Switching Center (MSC). It acts like a normal switching node of the PSTN or ISDN, and additionally provides all the functionality needed to handle a mobile subscriber, such as registration, authentication, location updating, handovers, and call routing to a roaming subscriber. – The Home Location Register (HLR) and Visitor Location Register (VLR), together with the MSC, provide the call-routing and roaming capabilities of GSM. – The location of the mobile is typically in the form of the signalling address of the VLR associated with the mobile station.
  8. 8. GSM : How do you get Connected… – This is done through Radio Links. The ITU allocates units of spectrum bands for a particular service providers. Usually, ranges from 890-915 MHz for uplink & 935-960 for downlink. – This method chosen by GSM is a combination of Time- and Frequency-Division Multiple Access (TDMA/FDMA). – The fundamental unit of time in this TDMA scheme is called a Burst period and it lasts 15/26 ms (or approx. 0.577 ms). – Eight burst periods are grouped into a TDMA frame which forms the basic unit for the definition of logical channels. One physical channel is one burst period per TDMA frame.
  9. 9. GSM : Reason for NOT REACHABLE – A traffic channel (TCH) is used to carry speech and data traffic. Traffic channels are defined using a 26-frame multiframe, or group of 26 TDMA frames. Out of these… – TCHs for the uplink and downlink are separated in time by 3 burst periods, so that the mobile station does not have to transmit and receive simultaneously, thus simplifying the electronics. – BSNL – 2, Spice Telecom – 2.35, Hutch – 2.80, Airtel- 2.9 and some AT&T Networks in UK&USA makes use of 3Burst periods. This affects the data & speech transmission(ISDN). – The next generations of connectivity, to avoid some of demerits of GSM, “ Universal Mobile Telecommunication System (UMTS).”
  10. 10. PLATFORMS
  11. 11. CDMA
  12. 12. The History – During 1985, ITU founded another group Interim Working Group, which was into determination of overall objectives of FPLMTS. This study came up with the benefits of integrating Terrestrial & satellite components. – This has boosted for dividing up the signal into many tiny fractions of a second, allowing three times as many people to use the system at the same time. – In 1992, San Diego's Qualcomm Inc. introduced a new flavor of an idea that has been used in military satellites for decades. And that is C D M A…
  13. 13. – TIA endorsed a wideband CDMAOne for ITU 3G solution and LG was the first company to introduce this data service worldwide. In 2000, This technology came to India. • The CDMA path in brief: CDMA2000 technology, data rates increase from 115Kbps to over 2Mbps. CDMA phones are already capable of handling packet data (data broken up into manageable chunks, each containing the destination address—the kind of data transmission used in the Internet). CDMA networks use standard Internet protocol (IP)- based equipment.
  14. 14. Merits with C D M A … • Good subjective speech quality • Support for international roaming • Support for range of new services and facilities • Spectral efficiency • The output stream is 64Kbps & compatible special quality of SIMs. Demerits with C D M A … • Handsets are more sensitive to handling & costlier. • Switching to different services is almost not possible. • Service providers are few in number. (RIL, Idea, Tata)
  15. 15. GSM Vs. CDMA GSM CDMA • 56 Kbps • 64 Kbps, 2Mbps • Conferencing- Impossible • Possible • Mixing (Cross-connection) • Rarely • Radiations are harmful. • Less harmful. • Voice clarity not so good. • Best • Compatibility is not good. • Its good • GPRS enabled, but poor quality pics & MP3 downloads. • Handsfree connectivity & Clarity.
  16. 16. ACRONYMS 1x— The first phase of CDMA2000 1xEV— An enhancement to CDMA2000 (1x) that includes HDR 3G— Third Generation of mobile communications 3x— CDMA2000 using three carriers of 1.25 MHz each 8 PSK— Eight-phase-shift keying AMPS— Advanced Mobile Phone Service
  17. 17. Acronyms CDG— CDMA Development Group CDMA— Code Division Multiple Access CDMA2000— The CDMA solution for 3G as defined by the TIA EDGE— Enhanced Data rates for Global Evolution ETSI— European Telecommunications Standards Institute FPLMTS— Future Public Land Mobile Telecommunications System
  18. 18. Acronyms GMSK— Gaussian minimum-shift keying GPRS— General Packet Radio Service GPS— Global Positioning System GSM— Global System for Mobile Communications (originally Groupe Spécial Mobile) HDR— High Data Rate IMT2000— International Mobile Telecommunications
  19. 19. Acronyms IP— Internet protocol IS-2000— The standard written by the TIA for 3G CDMA ITU— International Telecommunications Union TDMA— Time division Multiple Access TIA— Telecommunications Industry Association UMTS— Universal Mobile Telecommunications System UPT— Universal Personal Telecommunications WCDMA— Wideband CMDA