mobile networks evolution

8/7/2019 Mobile Networks Evolution

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Towards 4G

Gandhar Gokhale


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Commercial Launch in 1970s

Analog service modulation of carrier

Digital connectivity beyond the radio towers

FDMA

Various standards NMT (Nordic), AMPS (US),

TACS (UK), JTACS (Japan) etc

Introduced Cellular system AMPS from Bell Labs


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It was quite successful despite many shortcomings

In every city where mobile telephoneservice was introduced waiting lists

developed, growing every year. By 1976only 545 customers in New York Cityhad Bell System mobiles, with 3,700

customers on the waiting list. Aroundthe country 44,000 Bell subscribers

had AT&T mobiles but 20,000 peoplesat on five to ten year waiting lists.


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A channel is apair of

frequencies.

One frequency totransmit & One to

receive

It makes up acircuit or acomplete

communicationpath

Many radiotowers

User density

Terrestrialconditions

Each towercovering specificgeographic area

Typically with

overlaps


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Backhaul

Connects the radiotowers to the restof the telephone

network

The network consists oftwo parts

Access or terrestrial network

user location and mobility

Core Network

transportation & control of calls


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Very lowcapacities

Nostandardizationacross regions

Quite insecure

analog radiointerface


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Started inFinland in

1991 byRadiolinja

Digitalservice

Increasedcapacity

Airinterface:TDMA or

CDMA

GSM Europe &

~80%

countriesin general

CDMA-USA and

somecountries

in AsiaAddeddata

services

SMS andemail

Enhancedsecurity

andprivacy

Nopacket

dataservice


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BaseStation

BaseStation

Controller

MobileSwitching

Center


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SIM SubscriberIdentification Module Mini 25 mm X 15 mm

Micro 15 mm X 12 mm

IMSI International MobileSubscriber Identity

Stored in the SIM

Radio tranceiver Multiple radio technologies

Micro-SIM with mini-SIM and fullSIM brackets from Telia in Sweden


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Authenticate to

network

Perform securityoperations such

as ciphering

Measure radiosignal qualitycontinuously

Assist in mobility(handover)

Update the

network with thecurrent location


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BTS

Radio Tx/RX

Multiple transceivers for multi-sector

BSC

Controls hundreds of BTSs

Radio channel allocation

Inter-BTS handovers

MSC

Call Switching

Mobility

Connects to PSTN

Connects to HLR/VLR

Connects to 3G nodes

HLR, VLR& AuC

Subscriber information SIM-IMSI

Identification andAuthentication

Roaming


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Same components as for voice call with additional elementsSMSC - Short Message Service Center - relays SMSsSMC G/IW MSC - An MSC capable of supporting SMS


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Authentication

SIM and IMSI Shared secret Ki in SIM

Encryption ofRadio

Communication Algorithms such as

Kasumi and Snow

PhysicalNetwork

Security of corenetwork


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General Packet Radio Service: Sometimes called as 2.5G Speeds up to 56-114 kbps

CDMA counterpart: 1xRTT

Enhanced Data rate for GSM Evolution: 2.75G Speeds up to 236.8 kbit/s (with end-to-end latency of less

than 150 ms)


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Main support node

Handles routing and mobility

SGSN: Serving GPRS Support Node

Gateway to packet data network

Allocates address for handset

Implements firewall, NAT, Router etc

Validates subscriber details with RADIUS server

GGSN: Gateway GPRS Support Node

Typically Sits at BSC

Connects directly to SGSN

Differentiates between circuit switched data/voice and packet switched

data

PCU: Packet Control Unit


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Access Point Name: Name of the service provider

APN

GPRS Exchange: Connects to GGSN in the homenetwork from the SGSN of the visited network

GRX

SGSN and GGSN tunnel the data packets

between them using GTP

GTP


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E-mail; fax; unified messaging; intranet/Internet access

Communications

Information services; games

Value-added services

Retail; ticket purchasing; banking; financial trading

E-commerce

Navigation; traffic conditions; airline/rail schedules; location finder

Location-based applications

Freight delivery; f leet management; sales-force automation

Vertical applications

Advertising


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Real timevideo calls

HD gaming

Fast browsingand downloads

Live TV onmobile

Real time

streaming ofmusic and videos


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3GPP Release 99: WCDMA Initial spectrum allocated

1885 2025 MHz 2110 - 2200MHz

Later added 2500 2690 MHz 806 900 MHz 1710 1885 MHz

Spread Spectrum, 5 MHz spectrum Circuit Voice and Packet Data (up to 384 Kbps)

Deployed since 2003


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UTRAN UMTS Radio Access Network

Core Network expanded to two components

BTS Node B

BSC RNC

CoreNework

CS

2G 3G

PS


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CS domain: cells are partitioned into Location Areas

(LAs) The LA of the phone is tracked by VLR

PS domain: cells are partitioned into Routing Areas(RAs).

RA is tracked by SGSN In UMTS the RA is further subdivided into UTRAN RAs

(URAs)

During a connection GPRS SGSN tracks the cell of the

phone while UMTS SGSN tracks the URA and cell.

For tracking a handset the cells in the GPRS/UMTS service area are partitioned intogroups . To deliver services to the mobile phone cell group will page the phone


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PMM Detached (Idle)

UE is not reachable

PMM Connected(Ready)

PS signaling connection is established Packet transmission is possible

Cell-based/URA location update is performed

Serving RNC-Id is stored PMM Idle (Standby)

RA-based location update is performed

PS Signaling connection is released


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MM state model in SGSN

RRC state model in UTRAN


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HardHandover

All the old radio links in the UE are removed beforethe new radio links are established.

Seamless hard HO - The HO is not perceptible to theuser

Non-Seamless Hard HO

SoftHandover

The radio links areadded and removed in

a way that the UEalways keeps at leastone radio link to the

UTRAN.

Soft HO is performedby means of macro

diversity, (several radiolinks are active

simultaneously)

Softerhandover

A special case of Soft HO where the radio links thatare added and removed belong to the same Node B

Inter RAT (3G-2G) handovers: No UMTS coverage, UMTS capacity full

and GSM available etc.


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A 3G system derived from the IS-95 CDMA 2G systems

Standardized by 3GPP2

Since 2002

Prevalent in North America and South Korea The latest release EVDO Rev B

offers peak rates of 14.7 mpbs down link.


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HSDPA HighSpeed Downlink

Packet Access Downlink Only; DataOnly

Multiple Codes perSubscriber

Up to 16 QAM, Peak

Rates of 14.4 Mbps Deployed since 2005

HSUPA HighSpeed Uplink PacketAccess

CDMA, SpreadSpectrum, 5 MHz

Uplink Only; Data Only

Multiple Codes perSubscriber

Up to 16 QAM, PeakRates of 4.5 Mbps

Deployed since 2007

HSPA+ -High Speed

Packet AccessUp to 64 QAM,MIMOPeak Rates up to

DL 56 Mbps,UL 22 Mbps


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ITU-R launched the IMT-Advanced (4G) initiative in 2002 High speed

100 Mbps @ speeds upto 250 km/hr 1 Gbps @ stationary/pedestrian speeds

Compatibility of services within IMT and with fixednetworks

Capability of interworking with other radio access systems

High quality mobile services

User equipment suitable for worldwide use User-friendly applications, services and equipment

Worldwide roaming capability


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Clear WiMAX 4G vs 3GCheck out this video on You Tube
http://www.youtube.com/watch?v=1Bj2N1gTunghttp://www.youtube.com/watch?v=1Bj2N1gTunghttp://www.youtube.com/watch?v=1Bj2N1gTunghttp://www.youtube.com/watch?v=1Bj2N1gTunghttp://www.youtube.com/watch?v=1Bj2N1gTung


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Proposed by NTT DoCoMo , Japan Peak data rate:

100Mbps for DL with 20MHz (2 Rx Antenna at UE), 50Mbps for UL with 20MHz

Spectral efficiency: 5bps/Hz for DL 2.5bps/Hz for UL

Improved cell edge performance (in terms of bit rate) 2-4 times Rel 6

Reduced latency 5 30 ms user plane

Mobility Optimized for 0-15 km/hr 15-120 km/hr supported at high performance Max speeds 350-500 km/hr


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Physical (radio) channels DL: OFDM

UL: Single Carrier FDMA

Minimum antenna requirement: 2 at UE

2 at eNodeB

Beamforming

MIMO use of multiple antennas at both the transmitter and

receiver to improve communication performance


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All IP Core network : Evolved Packet Core Always On experience

IPsec mandatory for transport

Evolved Radio Access Network: E-UTRAN Evolved NodeB

LTE + E-UTRAN + EPC => SAE (Service ArchitectureEvolution)

Simplified architecture due to reduced network nodes


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End of circuit switched voice All IP network. VoIP.

Voice is just another IP based application

End-to-End QoS To support the media-rich, low latency and real time

services

Policy Management and Enforcement


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Manages user plane mobility

Maintain data paths between eNodeB and PGW

Anchor for local (intra-E-UTRAN) mobility

Mobility interoperation with other 3GPPtechnologies


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Interfaces with packet data networks such as Internet

Policy enforcement

operator defined rules for resource allocation and usage

Packet filtering

Deep packet inspection

Charging support

Per-URL charging


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Signaling and control functions

Manage access to network

Assignment of network resources Mobile states management(tracking/paging/roaming/HOs)

Security procedures

User authentication

Cipher and integrity protection protocol initiation


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Charging support

Per-URL charging

Policy enforcement

operator defined rules for resource allocationand usage


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Worldwide interoperability forMicrowave Access

IEEE 802.16 standard

Originally for last mile access

Lacked mobility before 802.16e-2005

IEEE 802.16m version proposed for 4Gi.e. 1 Gb/s speeds

HTC on Yota networks in Russia HTS on Sprint Nextel

IP based core network WiMAX Base Station


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Version Release Time Info

Phase 1 1992 GSM features

Release 96 1997 Q1 GSM Features, 14.4 kbit/sUser Data Rate,

Release 97 1998 Q1 GSM Features, GPRSRelease 99 2000 Q1 Specified the first UMTS

3G networks,incorporating a CDMA airinterface

Release 4 2001 Q2 Originally called theRelease 2000 - addedfeatures including an all-IP Core Network

Release 5 2002 Q1 IMS & HSDPA

Release 7 2007 Q4 HSPA+, NFC


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Version Release Time Info

Release 8 2008 Q4 LTE, SAE

Release 10 In progress LTE Advanced => IMTAdvanced i.e. 4G

Release 11 & Release 12 In progress Definition and scoping inprogress


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Spectrum as a limited resource => Arbitration Regulation for business malpractices such as

monopoly

FCC of the USA established in 1934 mostly to regulate landline

Included spectrum allocation also

DoT Govt. of India

Policy Making TRAI

Regulate service providers

mobile networks evolution

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