Thursday, 26 June 2014

All Generation




1 G ( First Generation )

Started in 1980.

 Features of 1 G:-

  • Analog in nature
  • Only FM ( Frequency Multiplexing), FDMA ( Frequency Division Multiple Access),       FDD ( Frequency Division  Duplexing ).
  • Only work on Frequency
  • Voice only ( no Data Transfer and no SMS )
  • Limited Regional Scope
  • No international roaming
  • All the Technologies where incompatible with each other.
  • Example  of 1 G -- 
                    AMPS ( US),
                    TACS ( UK), ETACS ( UK),
                    NMPT- 450 ( Europe), NMPT- 900 ( Europe),
                    Radicomm-2000 ( France) , 
                    NETZ  (Germany ) 

 Disadvantages of  1 G:-

  • Low capacity
  • No security
  • Costly services
  • Large handsets
  • High power consumption
  • Poor hands off / hand over
  • Poor voice quality
  • Inefficient spectrum utilization




2 G ( Second Generation) 

2nd generation Digital Cellular System Standard 

  • NOTE:- In India, we started from here . India adopt 2 G ( GSM ) as  in 1992
  • GSM used GMSK ( Gaussian Minimum Shift Keying ) Modulation

Features of 2 G:-

  •  All the Technologies were  Digital in nature.
  • Support voice + data
  • Concept of SMS and Fax was introduce
  • All the 2 G Technologies were compatible with fixed Digital Line Network like ISDN, Internet, PLMN.
  • It provide international roaming
  • Better voice quality
  • Low power consumption
  • It is classified in 2 sub-categories - TDMA & CDMA
             TDMA example - GSM, PDC ( Japan), IS-136
             CDMA example - IS-95


Advantages of 2 G:-  

  • Advantage of Digital over Analog like easy to multiplex, easy to Encrypt, more data security, less expensive compare to 1 G, more reliable.
  • Digital signal can be transmitted  over long distance without distortion.
  • Better spectrum utilization
  • Smaller handsets
  • Low power consumption

Disadvantages of 2 G:-

  • Low speed Data transmission 
  • GSM speed ( 9.6 Kbps to 14.4 Kbps)
  • No support for packet data transfer
  • Semi global roaming
  • Lots of Network equipment / elements
  • Long call setup time
  • Expensive services as compared to 2.5 G.








      2.5  G

       started in late 1990's


          These are 2 G system that have incorporated Packet Switching and Circuit Switching.


      Features  of  2.5 G:-

      • High data rate 
      • Global Roaming
      • Internet, Radio, Email, other multimedia services introduced.
      • Example - Data rate of GPRS - 115Kbps  & HSCSD - 57.6 Kbps
      • It allows existing 2 G network equipment to be modified by new base station addons.
      • Subscriber  unit ( mobile) was  also upgraded at software level to support high data rate .
      • It can support high speed application like Emails, Multimedia services, web browsering etc.






       2.5 G is sub divided in two parts :- 1. HSCSD & 2. GPRS

      HSCSD 

      ( HIGH SPEED CIRCUIT SWITCH DATA)

      • It is a part of 2.5 G.
      • GSM  gives a data rate of 9.6 Kbps to 14.4 Kbps by using 1 Time Slot but HSCSD give 4 Time Slot per user. Hence Data Rate increases to 4* 14.4 Kbps  = 57.6 Kbps.
      • Minimum network change required.

      Disadvantage of HSCSD:-

      • Based on Circuit Switching which inefficient for Packet Data Transfer.


      GPRS
      ( GENERAL PACKET RADIO SERVICES)


      Features of GPRS:-

      • Totally based on Packet switching.
      • Non - voice
      • Value added
      • High speed
      • Packet swtching
      • Data rate is 115 Kbps
      • GPRS reserve radio resource only when there is data to be transferred or received . Thus Providing efficient resource utilization.
      • It allows sending & receiving small burst of data like Email as well as large files over PLMN( Public Landline Mobile Network).

      Advantages of GPRS:-

      • High data rate ( 3 to 8 times higher speed than GSM).
      • Instant connection to internet and service access any time any where.

      Disadvantages of GPRS:-

      • Much low speed in reality
      • No support for MTC ( Mobile Terminated Call)
      • Sub- optimal ( GMSK) modulation was used ( GMSK - Gaussian Minimum Shift Keying ) Modulation)
      • High transit delay ( Propagation delay )
      • No store and forward technique is used.



      2.75 G( EDGE)

      Enhance Data Rate for GSM Evolution

      • EDGE was introduced.
      • High data rate 384 Kbps
      • In it 8 PSK modulation scheme is used
      • Multiple coding schemes are used ( MSC-1  to MSC-9). 

        3 G WCDMA/ UMTS


        (WIDE BAND CODE DIVISION MULTIPLE ACCESS /

        UNIVERSAL MOBILE TELECOM SERVICES)


        • 3G is merger of- 

        (Telecom Services) + (Data communication services) + (Multimedia Services)


        •  It’s a Next Generation Technology that support greater Band Width & better service   capability

        Features of 3G:-


        • Data rate up to 2Mbps
        • Better spectrum utilization
        • Mechanism to support Bandwidth on demand & variable bit rate services
        • Support for services with different QoS ( Quality of Services) requirement
        • Support for Real Time and Non Real Time Data Transfer
        • BER (Bit Error Rate) is less than 10^-6.
        •  Simultaneously co-existing with 2G network
        • Intra System Hand Over
        • High Spectrum Efficiency












          3.5 G (HSDPA / HSUPA)       
          (HIGH SPEED DOWN-LINK PACKET ACCESS /

          HIGH SPEED UP-LINK PACKET ACCESS)



          HSDPA
          HSUPA
          HIGH SPEED DOWN-LINK
           PACKET ACCESS
          HIGH SPEED UP-LINK
          PACKET ACCESS
          DATA RATE UP TO
             10 to 14 Mbps
          DATA RATE UP TO
            5 Mbps
              

          •   Higher  Modulation Schemes are used like 16 QAM ( Quadrature Amplitude Modulation)


          3.75G (HSPA+)

          (HIGH SPEED PACKET ACCESS ADVANCE)


          • Data rate up to 50 Mbps
          • High speed achieve through MIMO (Multi Input Multi Output )  ( This is an Antenna solution).


          3.9 G              

          (LTE / SAE)             

                   (LONG TERM EVOLUTION /                   

            SYSTEM ARCHITECTURE EVOLUTION)            



          Disadvantage of 3 G:-

          • Low data rate for high speed application like multimedia , video etc.
          • Very costly services
          • High transit delay i.e. latency greater than 100 ms
          • Now a days consumer wants high speed ( up to 100 Mbps) at a low cost
          • Today it is desired to migrate from circuit switched voice to packet data infrastructure, so as to reduce the cost of maintaing  two different network
          • Not optimized  for real time application & IP based multimedia services.





          4 G ( LTE ADVANCE)

                          (LONG TERM EVOLUTION ADVANCE)  

          • 4 G is also a merger of -
          (Telecom Services) 


          • Its is based on  OFDMA ( Orthogonal Frequency division Multiplexing Access) modulation.
          • High speed data 
          • Parallel send and receive data ( this is a feature of OFDM and all other technologies based on serially send and receive of data )
          • It use multiple antenna technique
          • Packet oriented network design based on IP ( Internet Protocol ) / VoIP( Voice over Internet Protocol)




            Features of 4G:-

            • High data rate ( Downlink data rate is greater than 100 Mbps and Uplink data rate is greater than 50 Mbps)
            • Low latency ( less than 50 ms)
            • Better spectrum utilization
            • Low cost
            • Inter-working  with other 3G System i.e. Backward Compatible
            • Less network nodes so less complex network  and less expensive
            • Reduced cost per bit ( to send a bit from A to B is reduced)
            • Advance services and better user experiences. 

            Graph of 4 G Technologies:-

            1 3GPP --> UMTS --> HSDPA/ HSUPA --> LTE

            2. 3GPP2 --> CDMA- 2000 --> EV-DO --> XUMB

            3.  WiMax --> 802.16 (fixed) --> 802.16e

            4. WLAN --> 802.11 --> 802.11 b/g --> 802.11n

            Note :- All bold are 4 G technologies.






            All Generation Handsets




            Varies Releases


            1. R99 - Release 99  - in it  data rate is 2 Mbps & but practical value is 384 Kbps
            2. R4 - Release 4 - separate Circuit Switch & Packet Switch domain & introduction to IP ( Internet Protocol) ( IPv4 & IPv6)
            3. R 5- introduction to HSDPA & Multimedia subsystem completed
            4. R6 - introduction to HSUPA & data rate increases & Multimedia broadcast multicast services ( MBMS) introduced
            5. R7 - HSPA+ was introduced , High modulation schemes were introduced & MIMO concept was introduced
            6. R8 - LTE Released  & Home-eNodeB concept was introduced
            7. R10 - LTE Advance was introduce.