Second Generation of Cellular Telephone Technology(2G)

Second Generation of Cellular Telephone Technology(2G)

1. Welcome to my Presentation

2. Topics: Second Generation of Cellular Telephone Technology(2G) 7/25/2016 2

3. 2G TECHNOLOGY 2G technology refers to the 2 nd generation which is based on GSM. It was launched in Finland by Radiolinja in the year 1991. 2G network use digital signals. It’s data speed was up to 64kbps. 7/25/2016 3

4. Features Includes: It enables services such as text messages, picture messages and MMS(Multi Media Message). It provides better quality and capacity. It brings more clarity to the conversation and both these circuit-switching model. In case of 2G the roaming facility a semi-global facility is available. In case of 2G Narrow Bands Wireless Digital Network is used. The US uses an additional GSM 1900 Example: GSM, cdmaOne , D-AMPS 7/25/2016 4

5. Mobile 2G digital technologies increased voice capacity 7/25/2016 5 Delivering mobile voice services to the masses – more people, in more places

6. Mobile 2G digital wireless technologies enabled more users Initial 2G technologies (D-AMPS, GSM) based on TDMA 7/25/2016 6

7. Different Mobile 2G TDMA techniques were standardized 7/25/2016 7

8. 8 Four popular standards for 2G 1.GSM 2.IS-136 3.PDC 4. IS-96 Global System for Mobile (GSM) Deployed widely in Europe, Asia, Australia, South America, and some parts of the U.S. in the PCS band of spectrum. GSM uses SIM T-Mobile, AT&T, and Cingular in the U.S.

9. 9 Interim Standard 136 (IS-136) Popular in North America, South America, and Australia. Cingular and AT&T in the U.S. Both companies have larger areas for their TDMA networks

10. 10 Pacific Digital Cellular (PDC) Japanese standard Interim Standard 95 (IS-95) CDMA Also known as cdmaOne Sprint and Verizon in the U.S.

11. 11 New standards for data over 2G Called 2.5G technology Allows existing 2G equipment to be modified for higher data-rate transmissions. More advanced applications are possible. Web browsing Wireless Application Protocol (WAP) that allows standard web pages to be viewed in a compressed format. E-mail Mobile commerce Location-based services (maps, directions, etc.)

12. 2G Technologies cdmaOne (IS-95) GSM, DCS-1900 IS-54/IS-136 PDC Uplink Frequencies (MHz) 824-849 (Cellular) 1850-1910 (US PCS) 890-915 MHz (Eurpe) 1850-1910 (US PCS) 800 MHz, 1500 Mhz (Japan) 1850-1910 (US PCS) Downlink Frequencies 869-894 MHz (US Cellular) 1930-1990 MHz (US PCS) 935-960 (Europa) 1930-1990 (US PCS) 869-894 MHz (Cellular) 1930-1990 (US PCS) 800 MHz, 1500 MHz (Japan) Deplexing FDD FDD FDD Multiple Access CDMA TDMA TDMA Modulation BPSK with Quadrature Spreading GMSK with BT=0.3 p/4 DQPSK Carrier Seperation 1.25 MHz 200 KHz 30 KHz (IS-136) (25 KHz PDC) Channel Data Rate 1.2288 Mchips/sec 270.833 Kbps 48.6 Kbps (IS-136) 42 Kbps (PDC) Voice Channels per carrier 64 8 3 Speech Coding CELP at 13Kbps EVRC at 8Kbps RPE-LTP at 13 Kbps VSELP at 7.95 Kbps

13. An interim stage that is taken between 2G and 3G that is 2.5G Features includes :- Phone calls/ Fax Voice mail Send/Receive e-mail messages web browsing camera phones speed: 64-144 kb/sec Time to download a 3 min MP3 song: 6-9 min 2.5 G wireless

14. 2G Capacity Digital voice data can be compressed and multiplexed much more effectively than analog voice encodings through the use of various  codecs , allowing more calls to be packed into the same amount of radio  bandwidth . The digital systems were designed to emit less radio power from the handsets. This meant that  cells  had to be smaller, so more cells had to be placed in the same amount of space. This was made possible by  cell towers  and related equipment getting less expensive. 7/25/2016 14

15. 2G Advantage The lower power emissions helped address health concerns. Going all-digital allowed for the introduction of digital data services, such as SMS and  email . * The lower powered radio signals require less battery power, so phones last much longer between charges, and batteries can be smaller. * The digital voice encoding allowed digital error checking which could increase sound quality by reducing dynamic and lowering the noise floor. * The lower power emissions helped address health concerns. * Going all-digital allowed for the introduction of digital data services, such as SMS and email. 7/25/2016 15

16. 2G requires strong digital signals to help mobile phones work. If there is no network coverage in any specific area , digital signals would weak. These systems are unable to handle complex data such as Videos. LIMITATIONS -

17. 1G vs 2G The primary differences between first and second generation cellular networks are: Digital traffic channels – first-generation systems are almost purely analog; second generation systems are digital. Encryption – all second generation systems provide encryption to prevent eavesdropping. Error detection and correction – second-generation digital traffic allows for detection and correction, giving clear voice reception. Channel access – second-generation systems allow channels to be dynamically shared by a number of users. 7/25/2016 17

18. Compare between 1G & 2G 7/25/2016 18

19. Question?? 7/25/2016 19

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