Basic Concepts of 2.5G Cellular Standards

1. Overview Of mobile
Cellular Communication
2.5G Cellular Standards
Presented By :
GAURAV BISWAS
(BIT MESRA)
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2. Index
 Evolution of 2.5G technology
 2.5G standards
 HSCSD
 GPRS
 EDGE
 IS-95B
 i-Mode
 References
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3. Evolution of 2.5G Technology
 1980s, cellphones operated on analog 1G technology
 Early 1990, Digital 2G technology became available on GSM standard
 2.5G wireless technology was a steppingstone that bridged second-
generation (2G) wireless technology and third-generation (3G) wireless
technology
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4. Evolution of 2.5G Technology
 The jump from 2G to 2.5 required just an upgrade over existing 2G
infrastructures
 It just needs compatible handsets and a few modifications to the base
stations
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5. 2.5 G standards
 HSCSD
 GPRS
 EDGE
 IS-95B
 i-Mode
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6. HSCSD(High Speed Circuit Switched Data)
 New high speed implementation of GSM
 Four times faster than GSM (transfer rate : 57.6Kbps)
 Operates across a GSM network(no extra hardware is required)
 Requires software upgrade
 Consecutive user time slots
 ideal for dedicated streaming internet access or real-time interactive web
sessions
 Inefficient use of channels
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7. GPRS (General Packet Radio service)
 Packet-based wireless communication service
 Data rate : 171.2 Kbps
 Provides continuous connection to the Internet
 Cost users less than circuit-switched services
 Upgraded network architecture(new network elements operates alongside the
existing element)
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8. GPRS Architecture
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[1] : GPRS Architecture

9. GPRS (General Packet Radio service)
 extension of existing 2G network
 capacity of launching packet based services
 packet switched domain in addition to circuit switched domain
 data rates : 56 Kbps upto 384 Kbps
 Provides secure communication
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10. Services
 Multimedia Messaging Service (MMS)
 Internet communication services : e-mail and World Wide Wireless Web
(WWW) access
 Data transfer is typically charged per megabyte of traffic transferred
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11. EDGE (Enhanced Data Rate for GSM Evolution)
 upgrade to the existing GSM / GPRS networks
 implemented as a software upgrade to existing GSM / GPRS networks
 Data rate higher than GPRS(up to 384 kbps)
 New network architecture entities that are needed for the EDGE upgrade are:
 SGSN
 GGSN
 PCU
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12. EDGE
 Uses 200 KHz bandwidth with 8 time slots
 48 kbps data rate in each time slot
 Requires advanced upgrades at BS
 Lesser coverage area
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13. IS-95B
 Evolution of IS-95
 Initial specification for the system was IS95A, but its performance was later
upgraded under IS-95B
 Data rate: 115 Kbps
 Improved voice quality
 Enables a greater number of users to be supported as compared to TDMA and
FDMA
 CDMA system re-uses the same channels
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14. i-Mode (Internet Mode)
 Evolved from PDC(Personal Digital Cellular)
 Supports text, graphics, audio, and video for Web access
 Packet-data transmission
 i-Mode phone utilizes a micro-browser to browse i-Mode enabled site
 i-Mode enabled website utilizes pages that are written in C-HTML
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15. References
 http://www.ques10.com/p/17454/explain-with-neat-diagram-hscsd-network-
architectu/
 https://www.gktoday.in/gk/gprs/
 http://wifinotes.com/mobile-communication-technologies/hight-speed-
circuit-switched-data.html
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