Edge

Evolution of Mobile Systems

cdmaOnecdmaOneCDMA2000 1x EV/DV

CDMA2000 1x EV/DV

3GPP CoreNetwork

HSDPA

HSDPA

EDGEEvolution

EDGEEvolution

CDMA2000 1xRTT

CDMA2000 1xRTT

CDMA2000 1x EV-DO

CDMA2000 1x EV-DO

UMTS

(WCDMA)

UMTS

(WCDMA) HSPDAHSPDA

CDMA2000 1x EV-DV

CDMA2000 1x EV-DV

3G

IS-95B(TDMA)

IS-95B(TDMA)

EDGEEDGEGPRSGPRSGSM(TDMA)

GSM(TDMA)

PDC(TDMA)

PDC(TDMA)

iDEN(TDMA)

iDEN(TDMA)

IS-136(TDMA)

IS-136(TDMA)

IS-95A(TDMA)

IS-95A(TDMA)

2.5G 2G

Global System for Mobile Communications (GSM)

GSM

82%

World GSM Subscribers

It is used by over 2 billion people across more than 212 countries

Global System for Mobile Communications (GSM)

• It started in the early 1980s

• It is the most popular standard for mobile phones in the world.

• The key advantage of GSM systems to consumers has been higher digital voice quality and low cost alternatives to making calls,

• GSM is a cellular network, which means that mobile phones connect to it by searching for cells in the immediate vicinity.

• GSM networks operate in four different frequency range

• 900 MHz or 1800 MHz bands.• 850 MHz and 1900 MHz bands• 935–960 MHz• 890–915 MHz,

GSM Network structure

Base Transceiver Station

EIREIR

AUCAUC

HLRHLRMSCMSC

BSCBSC

Base Station Subsystem(BSS)

• BSS is the section of a traditional cellular telephone network which is responsible for handling traffic and signaling between a mobile phone and the NSS.

• Base Transceiver Station(BTS), contains the equipment for transmitting and receiving of radio signals (transceivers), antennas, and equipment for encrypting and decrypting communications with the Base Station Controller .

• The BSC handles allocation of radio channels, receives measurements from the mobile phones, controls handovers from BTS to BTS.

• Packet Control Unit (PCU) performs some of the processing tasks of the BSC, but for packet data.

Network Switching Subsystem(NSS)

• NSS, is the component of a GSM system that carries out switching functions and manages the communications between mobile phones and the PSTN. The NSS, also referred to as the GSM core network.

• MSC is a sophisticated telephone exchange which provides circuit-switched calling, mobility management, and GSM services to the mobile phones roaming within the area that it serves.

• The 'Home Location Register' (HLR) is a central database that contains details of each mobile phone subscriber that is authorized to use the GSM core network.

• The 'Authentication Centre' ( AUC) is a function to authenticate each SIM card that attempts to connect to the GSM core network.

• The EIR (Equipment Identity Register) keeps a list of mobile phones (identified by their IMEI) which are to be banned from the network or monitored.

GPRS Core Network

• It is the centralized part of the GPRS system and also provides support for WCDMA based 3G networks. The GPRS core network is an integrated part of the GSM core network.

• A Gateway GPRS Support Node (GGSN) acts as an interface between the GPRS backbone network and the external packet data networks. It converts the GPRS packets coming from the SGSN into the appropriate packet data protocol and sends them out on the corresponding packet data network

• Serving GPRS Support Node(SGSN) :Detunnel GTP packets from the GGSN (downlink),Tunnel IP packets toward the GGSN (uplink) ,Carry out mobility management as Standby mode mobile moves from Routing Area to Routing Area, Billing user data

Subscriber Identity Module

• One of the key features of GSM is the Subscriber Identity Module (SIM), commonly known as a SIM card.

• The SIM is a detachable smart card containing the user's subscription information and phonebook. This allows the user to retain his or her information after switching handsets

About GPRS

• GPRS is a Mobile Data Service available to users of Global System for Mobile Communications (GSM) and IS-136 mobile phones.

• It is an expansion of GSM and a main step to 3G

• 2G cellular systems combined with GPRS is often described as "2.5G“

• GPRS is packet-switched, which means that multiple users share the same transmission channel, only transmitting when they have data to send

Contd…

• The multiple access methods used in GSM with GPRS are based on frequency division duplex (FDD) and FDMA.

• During a session, a user is assigned to one pair of up-link and down-link frequency channels.

• This is combined with packet mode communication, which makes it possible for several users to share the same frequency channel.

GPRS can be used for services such as

• Wireless Application Protocol (WAP) access • Short Message Service (SMS),• Multimedia Messaging Service (MMS),• GPRS will enable Internet applications, from web

browsing to chat, location based applications, e-commerce etc over the mobile network.

• Other new applications for GPRS, include file transfer and the ability to remotely access and control/monitor house appliances and machines.

• Enhanced Data rates for GSM Evolution (EDGE) or Enhanced GPRS (EGPRS)

• It is a digital mobile phone technology that allows it to increase data transmission rate and improve data transmission reliability.

• Although technically a 3G network technology it is generally classified as the unofficial standard 2.75G, due to its slower network speed. EDGE has been introduced into GSM networks around the world since 2003, initially in North America.

• It can be used both packet-switched and circuit-switched voice and data services. High-speed data applications such as video services and other multimedia benefit from EGPRS' increased data capacity.

About EDGE

• EDGE is an expansion of the GSM/GPRS protocol to support higher data rates. EDGE is add-on to GPRS

• This is accomplished by utilizing 8-PSK (8-Phase Shift Keying) modulation technique and modulation coding schemes at the physical layer.

• Offer data rates of 384kbps, theoretically up to 473.6kbps

• Uses Link adaptation algorithm for packet based radio system.• Modulation Bit rate – 810kbps• Radio data rate per time slot – 69.2kbps• User data rate per time slot – 59.2kbps • User data rate (8 time slots) – 473.6kbps

About EDGE

Why evolve EDGE?

• Economic forces – less costly than upgrading to UMTS

• Easy to offer global service to subscribers – 82% of world market is GSM which is already equipped for easy roaming and billing

• Higher data rates and system capacity

• Broadband-like speeds achievable

• Much less expensive mobiles

Services

EDGE In GSM Network

BTS

BSC

BTS

SGSN

MSC

A-bis

Gb

A

Gn

GGSNLaptop

8 -PSK coverage

GSM coverage

EDGE Capable TRX,GSM compatible

More capacity in interfacesto support higher data imageEDGE capable terminal

GSM compatible BTS

BTS -Base Transceiver StationBSC - Base Station ControllerSGSN - Serving GPRS Support NodeGGSN - Gateway GPRS Support NodeMSC - Mobile Switching Center

BSCBSCMSCMSC

Impact of EDGE on existing GSM/GPRS networks

• EDGE requires no hardware or software changes to be made in GSM core networks, base stations must be modified.

• EDGE compatible transceiver units must be installed

• Software upgrade to the BS and BSC

• The base station subsystem (BSS) hardware(new transceiver in each cell) needs to be upgraded to support EDGE

• New mobile terminal hardware and software is also required to decode/encode the new modulation and coding schemes and carry the higher user data

Phase-shift keying

• It is a digital modulation scheme that transmit data by changing, or modulating.

• Any digital modulation scheme uses a finite number of distinct signals to represent digital data.

• PSK uses a finite number of phases, each assigned a unique pattern of binary bits. Usually, each phase encodes an equal number of bits.

• Each pattern of bits forms the symbol that is represented by the particular phase. The demodulator, which is designed specifically for the symbol-set used by the modulator, determines the phase of the received signal and maps it back to the symbol it represents, thus recovering the original data.

Comparison

473.3

Technical differences between GPRS and EDGE

• EDGE is a subsystem within the GSM standard, GPRS has introduced packet-switched data into GSM networks.

• Basically, EDGE only introduces a new modulation technique and new channel coding that can be used to transmit both packet-switched and circuit-switched voice and data services.

• EDGE is an add-on to GPRS and cannot work alone. And is therefore much easier to introduce than GPRS. GPRS has a greater impact on the GSM system than EDGE has.

Technical differences between GPRS and EDGE

• EDGE offers significantly higher throughput and capacity. This decreases the number of radio resources required to support the same traffic, thus freeing up capacity for more data or voice services.

• EDGE can transmit three times as many bits as GPRS during the same period of time. This is the main reason for the higher EDGE bit rates.

Technical differences between GPRS and EGPRS

• With EDGE, the same time slot can support more users.

• GPRS and EDGE have different protocols and different behavior on the base station system side.

• On the core network side, GPRS and EDGE share the same packet-handling protocols and, therefore, behave in the same way.

• GPRS and EDGE share the same symbol rate, the modulation bit rate differs.

EDGE Advantages

• Time to market• Designed for existing spectrum: 800/900/1800/1900

MHz• Low risk technology evolution from GSM/GPRS

• GSM global scale & scope• Chipsets, handsets, infrastructure and applications • Lower capital investment, better vendor selection• Global roaming

• Short-term benefits: Capacity and performance• Easy implementation on a GSM/GPRS network

• Cost effective

• Increase the capacity and triples the data rate of GPRS• Enabling new multimedia services

Latin America:

Will eventually follow US.

eventually follow US.

GUS+Canada: EDGE roll-outs on the

wayE roll-outs on the way and EDGE Market follows global

trends. “Ongoing technology standard war”. Also public commitments to EDGE

China: Political commitments to every technology. No rush to 3G. No public EDGE commitments yet

Europe: WCDMA technology commitment.

Strong need for delaying UMTS roll-outsGrowing interest towards EDGE, but no public commitments yet.

Global EDGE Status

EDGE Operators In Asia

Conclusion

• EDGE transmit both packet-switched and circuit-switched voice and data services.

• High speed Data rates • EDGE Evolution continues in Release 7 of the

3GPP standard providing doubled performance e.g. to complement High-Speed Packet Access (HSPA).

• Voice over IP is planned for EDGE R’2000 standards

THANK YOU