This document provides an overview of 2.5G cellular standards, including HSCSD, GPRS, EDGE, IS-95B, and i-Mode. It discusses the evolution from 1G analog to 2G digital cellular technologies and how 2.5G served as an intermediate step between 2G and 3G. Key aspects covered include data transfer speeds and network upgrades needed for each 2.5G standard.

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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