mobile communicaton generations

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  • 1. Mobile communication generationsBY:- VATSALYA SAXENA

2. OverviewCommunicationgenerations1G 2G 3G 4G 3. First Generation Cellular SystemsFirst generation (1G) of cellular systems introduced in the late 1970s andearly 1980s1G systems were based on analogue communication in the 900MHzfrequency rangeVoice transmission onlyThe most prominent 1G systems areAdvanced Mobile Phone Systems (AMPS) - AmericaNordic Mobile Telephone (NMT) - FranceTotal Access Communications System (TACS) UKJan 1985 Vodafone introduced the TACS system 4. First Generation Cellular SystemsFrequency Division Multiple Access (FDMA) Splits allocated spectrum into 30 channels, each channel is 30kHz Allocates a single channel to each established phone call Ineffective methods since each analogue channel can only be used by one user at a time 5. First Generation Cellular SystemsFrequency Division Multiple Access (FDMA) 6. First Generation Cellular Systems LIMITATIONS Ineffective methods since each analogue channel can only be usedby one user at a time FDMA does not take full advantage of available spectrum Actual data transfer speed vary from 2.9kbps to 5.6kbps which is very low 7. 2G-TECHNOLOGY GSM(TDMA -based) IS-95(CDMA-based) PDC(TDMA-based) used in Japan iDEN (TDMA-based) used in United states IS-136 aka D-AMPS (TDMA-based) 8. GSM System Radio Interface Base frequency: 900MHz Channel spacing 200kHz Time Division Multiple Access (TDMA) Hard Handover (MAHO) Maximum Bandwidth available: 9600 bits per second 9. GSM System Multiple AccessTime Division Multiple Access (TDMA) Allows larger transmission rates than in an FDMA system Based on the idea to break individual frequencies into 8 timeslots of is 0.577 ms length (total 4.615ms) these are referred to as a frame Each mobile device uses a particular slot different from slots used by other users Information transmitted in one slot is referred to as burst TDMA requires timeslot synchronisation 10. GSM System Multiple AccessTime Division Multiple Access (TDMA) Guard Time: Interval between bursts used to avoid overlapping Preamble: First part of the burst Message: Part of burst that includes user data Postamble: Last part of burst used to initialise following burst MultiframeFrame 1Frame NSlot 1Slot 2 Slot i Slot 8 .. Slot 1 Slot 8Slot Guard TimePreambleMessagePostambleGuard Time 11. GSM System Multiple AccessTime Division Multiple Access (TDMA)TimeFrequency 12. GSM-Supplementary Services User Identification Emergency Calls Call Hold Advice of Charge Call Barring Call Forwarding Multiparty calls 13. GSM System Multiple AccessCode Division Multiple Access (CDMA) Multiple access technique used by american System (NOT used by the European GSM system) Based on the spread-spectrum technique Access technique realised before transmission by addition of a code that is independent of the data sequence Allows many devices to transmit simultaneously in the same frequency band 14. GSM System Multiple Access Code Division Multiple Access (CDMA) Code Channel 1 Channel 2 Channel 3Frequency Channel NTime 15. GSM System Multiple AccessCode Division Multiple Access (CDMA) CDMA provides protection against multipath fading interference, privacy, interference rejection, anti-jamming capability, low probability of interception and allows macrodiversity Handover Mobile-assisted handover (MAHO) as mobile measure signal strength but network-controlled as the network makes decision 16. Second Generation Cellular Systems Advantages- Phone conversations were digitally encrypted 2G systems were significantly more efficient allowing for far greatermobile phone penetration levels 2G introduced data services for mobile starting with SMS By a large majority of companies using the same technology theavailability to communicate across the infrastructures can be achieved(known as Roaming) 17. What Next.? 18. 3G-spacifications Technical specifications were made available under thename IMT-2000 by ITU Minimum transmission rates of 144 kbps in mobile (outdoor) and2 Mbps in fixed (indoor) environments Three of the five approved standards- CDMA2000 TD-SCDMA WCDMA 19. Difference between 2G and 3G TechnologyCostData TransmissionFunctionFrequenciesImplicationSpeed 20. 3G -TECHNOLOGY The main technological difference that distinguishes 3G technologyfrom 2G technology is the use of Packet switching rather than circuitswitching for data transmission CDMA2000-1X delivers theoretical maximum data speeds of up to307 kbit/s . 3.5G, 3G+ or turbo 3G, which allows networks based on UniversalMobile Telecommunications System (UMTS) to have higher datatransfer speeds and capacity. 3GPP standards introduce a maximum downlink speed of 42Mbps 21. Limitations of 3G Difficulty of CDMA to provide higher data rates Need for continuously increasing data rate andbandwidth to meet the multimedia requirements Limitation of spectrum and its allocation Inability to roam between different services To introduce a better system with reduces cost 22. 4G - Technology 3G technology with more bandwidth and services . The first two commercially available technologies billed as 4G were theWiMAX standard and the LTE standard 4G networks are defined as networks that will offer speeds from 100 Mbpsto 1 Gbps, providing robust performance for the most bandwidth intensiveapplications, such as high quality streaming video WiMAX stands for Worldwide Interoperability of Microwave Accesspreviously worked as fixed wireless facility under the 802.16e band. Nowthe modified standard 802.16m has been developed 23. 4G-TechnologyLTE is developed on radio waves technology. LTE is using MIMO (Multiple input multiple output) 24. References H yumiba et al:overview of IMT-2000 network systems,Ntt DoCoMotech. journal,6,4,p.8-13(1999) K. yamamoto et al:Core network technologies. Ntt docomo tech.journal,3,3,p.16-30(2001) 25. QUERIES....??? 26. thank you