redes moveis e mobilidade - fenix.tecnico.ulisboa.pt · 3 redes moveis e mobilidade departamento de...

Artur Arsenio

Redes de Computadores 2010/2011

Departamento de Engenharia Informtica1

Redes de ComputadoresRedes de Computadores

Redes Moveis e

Mobilidade

Artur Arsenio


Departamento de Engenharia Informtica2 Redes Moveis e Mobilidade

Redes Moveis e Mobilidade

Redes sem Fios

Caracteristicas de Redes sem Fios CDMA

IEEE 802.11 wireless LANs (wi-fi)

Redes Celulares arquitectura

standards (e.g., 3G)

Mobilidade

Principios endereamento e encaminhamento para utilizadores mveis

Mobilidade IP

Mobilidade em Redes Celulares

Mobilidade e Protocolos de alto nvel

Segue Capitulo 6 do livro de J.F Kurose e K.W. Ross

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Infra-estruturada rede

Estao base

Ligada tipicamente a rede com fio

Responsvel pela comunicaoentre os hosts mveis da sua rea e os hosts das redes infraestruturadas

e.g., torres celulares e pontos de acesso 802.11

Ligao sem fio

Usado para ligar osdispositivos mveis sestaes base

Controlado por protocolosde mltiplo acesso

Vrias taxas de transmissoe distncias mximas

Hosts sem fio

Laptop, PDA, telefone IP

Executam Aplicaes

Podem ser mveis ou no

sem fio nem sempresignifica mobilidade

Elementos de uma rede sem fios

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384 Kbps

56 Kbps

54 Mbps

5-11 Mbps

1 Mbps802.15

802.11b

802.11{a,g}

IS-95 CDMA, GSM

UMTS/WCDMA, CDMA2000

.11 p-to-p link

2G

3G

Indoor

10 30m

Outdoor

50 200m

Mid range

outdoor

200m 4Km

Long range

outdoor

5Km 20Km

Caractersticas das normas de algumas redes sem fios

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Infra-estrutura

da rede

Ligao Infraestrutura

Estao base liga osdispositivos mveis na redecom fio

handoff: dispositivo mvelmuda de estao base, ligando-se nova rede com fio

Modo de Ligao: Infraestrutura

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Modo Ad hoc

no existem estaes base

ns podem transmitir paraoutros somente dentro de umadeterminada cobertura

ns organizam-se em rede e o encaminhamento s pode ser feito entre eles

Modo de Ligao: Ad hoc

Modo Hibrido

Redes ad hoc ligadas infraestrutura de rede atravs de um ponto de acesso

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Diferenas para as ligaes com fios:

Diminuio da potncia do sinal: sinais de rdio sofrem maior atenuao ao longo do caminho (path loss)

Interferncia de outras fontes: frequncias normalizadas para redes sem fios (e.g. 2.4 GHz) so partilhadas por outros dispositivos (e.g. telefone) motores e outras fontes tambm interferem

Propagao multicaminho (multipath): sinal de rdio reflectido por vrios obstculos terrestres, chegando ao destino com pequenas diferenas de tempo

Faz da comunicao sobre uma ligao sem fios (mesmo ponto a ponto) muito mais difcil

Caractersticas das Ligaes sem Fios

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Propagao multicaminho (multipath)

Caracteristicas de propagaovariam com o tempo

Sinais chegam de vrioscaminhos ao receptor com nveisde potncia diferentes

e tempos de chegada (atrasos) tambm diferentes

Os efeitos de multipath incluem Interferncia constructiva e

destructiva

Deslocamento da fase (phase shifting) do sinal

(causa o Rayleigh fading)

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A existncia de vrios emissores e receptores sem fios cria problemas adicionais para alm do mltiplo acesso

AB

C

B, A escutam-se um ao outro

B, C escutam-se um ao outro

A, C no se podem escutar um ao outro A e C no prevem uma interf. em B

A B C

As signalstrength

space

Cs signalstrength

Atenuao do sinal

Caractersticas das redes sem fios

Problema do terminal escondido

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CDMA (Mltiplo Acesso por Diviso por Cdigo): explora esquema de codificao de espectro espalhado

DS (Direct Sequence) ou FH (Frequency Hopping)

Protege utilizadores da interferncia (inclusive a intencional)

usado desde a Segunda Guerra Mundial

protege utilizadores do multipath fading em rdio interferncia entre duas trajectrias do mesmo sinal; e.g. o directo e por reflexo

Cdigo nico associado a cada canal; i.e., partio do conjunto de cdigos usado em canais de radiodifuso (redes celulares, satlite)

Utilizadores partilham a mesma frequncia; cada canal tem sua prpria sequncia de chipping (i.e., cdigo)

sequncia de chipping funciona como uma mscara: usado para codificar o sinal

para o CDMA funcionar com mltiplos utilizadores e transmisses em simultneo com um mnimo de interferncia , as sequncias de chipping devem ser mutuamente ortogonais entre si (i.e., produto interno = 0)

Sinal codificado = (sinal original) X (sequncia chipping)

Descodificao: produto interno (soma dos produtos por componente) do sinal codificado pela seq. de chipping

CDMA: Partio do Canal

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CDMA: Codificao/Descodificao

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CDMA: Interferncia entre 2 emissores

Sequncias de chippingmutuamente ortogonais entre si

Ckm. cjm = 0, se i,j diferentes

Ckm. ckm = M

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Caracteristicas de Redes sem Fios Reviso

Redes sem Fios




standards (e.g., GSM)

Mobilidade

Principios endereamento e encaminhamento

para utilizadores mveis

Mobilidade IP



Elementos da rede sem fios

Caractersticas das normas

de algumas redes sem fios

Modo de Ligao:

Infraestrutura

Ad hoc

Caractersticas das ligaes

e redes sem fios

CDMA

Partio do Canal

Codificao / Descodificao

CDMA

Interferncia entre 2

emissores CDMA

Elementos da rede sem fios

Caractersticas das normas

de algumas redes sem fios

Modo de Ligao:

Infraestrutura

Ad hoc

Caractersticas das ligaes

e redes sem fios

CDMA

Partio do Canal

Codificao / Descodificao

CDMA

Interferncia entre 2

emissores CDMA

Artur Arsenio



IEEE 802.11 Wireless LAN

802.11bDirect Sequence SpreadSpectrum (DSSS) na camada fisica

todos os hosts usam o mesmo cdigo de chipping

2.4-2.485 GHz unlicensed radio spectrum

Espectro de frequncias de fornos microondas e telefones 2.4GHz

at 11 Mbps

802.11a 5.1-5.8 GHz range

at 54 Mbps

Alcane de distncias mais curtas

sofrem mais interferncias multipath

802.11g 2.4-2.485 GHz range

at 54 Mbps

Todos usam CSMA/CA para acesso multiplo

Suportam redes com estaes base e ad-hoc

Capacidade de reduzir ritmo de transmisso

para atingir distncias maiores

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BSS 1

BSS 2

Internet

hub, switchou router

AP

AP

IEEE 802.11 LAN - Arquitectura

Um host sem fios comunica com a estao base

estao base = access point (AP)

AP contm MAC nico para a sua interface de rede sem fios

Rede residencial tpica contm um AP, um router, e um

modem cabo ou ADSL (ou um terminal ptico)

Basic Service Set (BSS) (clula) no modo infraestruturado contm:

Hosts sem fios

access point (AP)

no modo ad hoc: somente hosts sem fios

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802.11: Canais, Associao

802.11b: o espectro 2.4GHz-2.485GHz (85MHz) dividido em 11 canais de frequncias diferentes que se sobrepem parcialmente

O administrador da rede escolhe um nmero de canal para o AP

Possvel interferncia: canal pode ser o mesmo que o escolhido por um AP vizinho!

No h sobreposio entre 2 canais estiverem separados por 4 ou + canais

Canais 1,6 e 11 nico conjunto de 3 canais no sobrepostos

host: deve descobrir APs dsponiveis, e ser associado com um AP Varre todos os canais, escuta tramas de sinalizao que contm a identificao

dos APs (SSID Service Set IDentifier) e o endereo MAC

Selecciona um AP para se associar

Pode realizar autenticao, exemplo: host comunica com servidor de autenticao usando um protocolo com o RADIUS [RFC 2138] ou o DIAMETER [RFC 3588]

simplifica a implementao do AP, pois servidor pode autenticar hosts de vrios APs

Executa, tipicamente, o protocolo DHCP para obter o end. IP na sub-rede do AP

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Evitar colises (CSMA/CA): 2 ou mais ns a transmitir ao mesmo tempo

802.11: usa o CSMA Acesso mltiplo por deteco de portadora escuta o meio antes de transmitir

para no colidir com outras transmisses em andamento

802.11: no realiza deteco de coliso Dificuldade em receber (escutar colises) quando est a transmitir devido fraqueza da

energia dos sinais recebidos (fading)

No pode escutar todas as colises: e.g. terminal escondido, fading

AB

CA B C

fora dosinal de A

espao

fora dosinal de C

IEEE 802.11: Acesso mltiplo

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Protocolo MAC do CSMA/CA IEEE 802.11

Emissor 802.111 se o canal estiver livre, espera um pequeno tempo

(Distributed Inter-Frame Space - DIFS) e ento transmite toda a trama (no h deteco de coliso)

2 se o canal estiver ocupado ento

i. inicia um tempo de backoff aleatrio

ii. faz contagem regressiva enquanto o canal estiver livrei. Se perceber que canal est ocupado, para contagem

iii. transmite quando o tempo expirar, e fica espera de ACK

iv. se no chegar um ACK, aumenta o intervalo de backoff e repete o passo 2

Receptor 802.11

- se a trama recebida estiver OKenvia ACK depois de esperar um SIFS - Short Inter-Frame Spacing (ACK devido ao problema do terminal escondido)

sender receiver

DIFS

data

SIFS

ACK

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Ideia: permitir ao emissor reservar o canal ao invs de realizar um acesso aleatrio das tramas, evitando colises de tramas longas

Devido a overhead, s usado p/ emisso de tramas longas (tamanho > limiar)

Emissor primeiro envia pequenas tramas de controlo request-to-send(RTS) para o AP usando o CSMA, mas que ouvido por todas as estaes ao seu alcance (inclusive o AP)

os pacotes RTS podem ainda colidir uns com os outros, mas como eles so pequenos, no causam longos atrasos

AP envia um pacote clear-to-send (CTS) para todas as estaes que esto ao seu alcance, em resposta ao RTS

Emissor transmite a trama de dados

Outras estaes bloqueiam as suas emisses

Evita completamente as colises de longas tramas

de dados usando pequenos pacotes de reserva!

IEEE 802.11: Evitar Colises

APH1 H2

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Evitar Colises: troca de RTS-CTS

APA B

tempo

RTS(A)

RTS(A)

CTS(A) CTS(A)

DATA (A)

ACK(A)ACK(A)

RTS(B)

Coliso de RTSs

Origem DestinoTodos os outros ns

bloqueiobloqueio

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frame

controlduration

address

1

address

2

address

4

address

3payload CRC

2 2 6 6 6 2 6 0 - 2312 4

seq

control

Formato da Trama 802.11

Address 2: endereo MAC

do host sem fios ou do AP

a emitir a trama

Address 1: endereo MAC

do host sem fios ou do AP

que vai receber a tramaSe pacote vem de host sem fios,

ento contm MAC do AP

Address 3: endereo MAC da interface

do router ao qual o AP est ligado

Address 4:

usado somente

no modo ad hoc

Bytes

Ty

pe

Relembrar: Trama Ethernet

Tipicamente detagrama

IP ou pacote ARP

Erros em bits mais

comuns nas redes

sem fios

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Internetrouter

AP

H1 R1

AP MAC addr H1 MAC addr R1 MAC addr

address 1 address 2 address 3

Trama 802.11

R1 MAC addr AP MAC addr

dest. address source address

Trama 802.3 (ethernet)

Uma das principais funes

de um AP converter uma

trama 802.11 para uma

trama ethernet e vice-versa

Trama 802.11: Endereamento

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frame

controlduration

address

1

address

2

address

4

address

3payload CRC

2 2 6 6 6 2 6 0 - 2312 4

seq

control

TypeFrom

APSubtype

To

AP

More

fragWEP

More

data

Power

mgtRetry Rsvd

Protocol

version

2 2 4 1 1 1 1 1 11 1

tempo de transmisso reservado (RTS/CTS) n de seq da trama (para tx fivel com ARQ)

Tipo da trama (associao,

RTS, CTS, ACK, dados)

Definem o significado dos campos address, que

mudam conforme o modo de uso infraestrutura

ou ad-hoc, e do emissor ser um host ou AP

Trama 802.11

Bytes

bits

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hub or switch

AP 2

AP 1

H1 BBS 2

BBS 1

router

802.11 - Mobilidade dentro da mesma subrede

H1 permanece na mesma subrede: endereo IP pode permanecer o mesmo (hub ou switch)

Switch: qual o AP que est associado com H1?

Self-learning: switches montam as suas tabelas de forma automatica, mas no esto aptos a lidar com mobilidade excessiva. Existe um par (peer) entre o endereo da sua interface e H1

Soluo: AP2 envia em broadcastuma trama ethernet com o endereo fonte de H1 logo depois da associao

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MRadio de

cobertura

S

SS

P

P

P

P

M

S

Master device

Slave device

Parked device (inactive)P

802.15: wireless personal area network (Piconet)

Dispositivos separados por, no mximo, 10 m de dimetro

Substitui dispositivos com fios por dispositivos sem fios (ratos, teclados, headphones)

ad hoc: sem infraestrutura

Mestre-escravo:

Mestre pode emitir em cada time slot impar

Escravos solicitam permisso para emitir ao mestre => Mestre fornece permisso

Dispositivos parked : no podem transmitir at o seu estado ser trocado para activo pelo mestre (at 255 numa piconet)

802.15: baseado na especificao Bluetooth 2.4-2.5 GHz espectro de rdio, em modo TDM, time slots de 625ms

Em cada time slot, emissor emite por um dos 79 canais

Emissor salta de canal em canal (Hopping) Conhecido como Frequency-hopping spread spectrum (FHSS)

Espalha emisses pelo espectro de frequncias ao longo do tempo

Em cada intervalo, o canal muda de maneira conhecida, porm pseudo-aleatria

Taxa de transmisso at 721 kbps

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IEEE 802.11 wireless LANs (wi-fi) Reviso

Redes sem Fios





Mobilidade

Principios endereamento e encaminhamento para

utilizadores mveis

Mobilidade IP



IEEE 802.11 LAN

Arquitectura

Canais, Associao

IEEE 802.11: Acesso

mltiplo

CSMA/CA IEEE 802.11

Evitar Colises: troca de

RTS-CTS


Endereamento

Mobilidade dentro da

mesma subrede

802.15: wireless personal

area network (Piconet)

IEEE 802.11 LAN

Arquitectura

Canais, Associao

IEEE 802.11: Acesso

mltiplo

CSMA/CA IEEE 802.11

Evitar Colises: troca de

RTS-CTS


Endereamento

Mobilidade dentro da

mesma subrede

802.15: wireless personal

area network (Piconet)

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liga celulas s redes de rea alargada

gere o estabelecimento de camadas

gere a mobilidade

MSC

Mobile

Switching

Center

Public telephonenetwork, andInternet

Mobile

Switching

Center

cobre regio

geografica

base station (BS)

anloga ao AP 802.11

utilizadores mveis

ligam-se rede atravs

da BS

interface-ar:

protocolos de camada

fisica e lgica entre o

dispositivo mvel e a BS

celula

wired network

Componentes da Arquitectura de Redes Celulares

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Redes Celulares: the first hop

Duas tecnicas para partilhar o espectro de frequncias radiomobile-to-BS

FDMA/TDMA combinado: dividir espectro em canais de frequncia, e dividir cada canal em parcelas (slots) de tempo

CDMA: code divisionmultiple access

frequency

bands

time slots

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Standards para Tecnologia Celular: Breve Perspectiva

2.5 G systems: canais de sinais de voz e dados Extenses do 2G

General packet radio service (GPRS) evoluiu do GSM

dados enviados em vrios canais (se disponiveis)

Enhanced data rates for global evolution (EDGE) Evoluiu do GSM, usando modulao melhorada

Ritmo de dados at 384K

CDMA-2000 (phase 1) evoluiu do IS-95

3G systems: voz/dados/video Universal Mobile Telecommunications Service

(UMTS)

Evoluo do GSM, mas usando CDMA

CDMA-2000

2G systems: canais para sinais de voz

IS-136 TDMA: uso combinado de FDMA/TDMA (na America do Norte)

GSM (global system for mobile communications): uso combinado FDMA/TDMA

IS-95 CDMA: code divisionmultiple access

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UMTS 3G Network ArchitectureCS Domain

CS (Circuit

Switched)

Domain

CS (Circuit

Switched)

Domain

BSS /RNS

BSS

(Ba

se

Sta

tion

Sy

ste

m) /

RNS

(Ra

dio

Ne

two

rkS

ys

tem

)...

...

HSS(Home Subscriber

Servers)

HSS(Home Subscriber

Servers)

PS Domain

PS (Packet

Switched)

Domain

PS (Packet

Switched)

Domain

MS (Mobile Station)MS (Mobile Station)

MS

Applications and Services

NMS(Network Management

Subsystem)

NMS(Network Management

Subsystem)

IMS (Internet

Multimedia

Subsystem)

IMS (Internet

Multimedia

Subsystem)

Ac

ce

ss

Ne

two

rk

Co

re

Ne

two

rkAccess Network Core Network

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Redes Celulares - Reviso

Redes sem Fios





Mobilidade

Principios endereamento e encaminhamento para

utilizadores mveis

Mobilidade IP



Componentes da

Arquitectura de Redes

Celulares

Partilha do espectro de

frequncias em redes

celulares

Redes Celulares: the

first hop

Standards para

Tecnologia Celular:

Breve Perspectiva

Componentes da

Arquitectura de Redes

Celulares

Partilha do espectro de

frequncias em redes

celulares

Redes Celulares: the

first hop

Standards para

Tecnologia Celular:

Breve Perspectiva

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Anexo

Arquitecturas 3G para Redes Mveis Celulares

(em Ingls)

Next Generation Architectures

Next Generation Architectures can be defined in terms of: Air interface data rate

Such as Internet Protocol over the air or 100 Mbps downlink

Innovative services and applications available to (and demanded by) users

Next Generation Architectures can be defined in terms of: Air interface data rate

Such as Internet Protocol over the air or 100 Mbps downlink

Innovative services and applications available to (and demanded by) users

Next Generation architecture design choices: all-IP network

focus on IP version 6 (IPv6)

Layered architecture of Application Programming Interfaces (APIs) Public and private

all designed to facilitate access to the network resources in a secure, useful, and billable manner.

Migration of intelligence from the core toward the periphery of the system In both IP-based networks as well as the Public Switched Telephone Networks (PSTNs)

Need for rapid and flexible deployment of applications

(some approaches are exploring the concentration of intelligence centrally, deploying multiple, cheaper antennas eg. RoF)

Next Generation architecture design choices: all-IP network

focus on IP version 6 (IPv6)

Layered architecture of Application Programming Interfaces (APIs) Public and private

all designed to facilitate access to the network resources in a secure, useful, and billable manner.

Migration of intelligence from the core toward the periphery of the system In both IP-based networks as well as the Public Switched Telephone Networks (PSTNs)

Need for rapid and flexible deployment of applications

(some approaches are exploring the concentration of intelligence centrally, deploying multiple, cheaper antennas eg. RoF)

The Vision for Third-generation International Telecommunications Unions (ITU) International Mobile

Telecommunications (IMT-2000) vision Common spectrum worldwide (1.82.2 GHz band)

Support for multiple radio environments (including cellular, satellite, cordless, and local area networks)

integration of satellite and terrestrial systems to provide global coverage.

Wide range of telecommunications services (voice, data, multimedia, and the Internet),

Flexible radio bearers for increased spectrum efficiency,

Data rates up to 2 Mbps in the initial phase,

Maximum use of Intelligent Network (IN) capabilities for service development and provisioning,

Global seamless roaming and service delivery across IMT-2000 networks,

Enhanced security and performance

International Telecommunications Unions (ITU) International Mobile Telecommunications (IMT-2000) vision

Common spectrum worldwide (1.82.2 GHz band)

Support for multiple radio environments (including cellular, satellite, cordless, and local area networks)

integration of satellite and terrestrial systems to provide global coverage.

Wide range of telecommunications services (voice, data, multimedia, and the Internet),

Flexible radio bearers for increased spectrum efficiency,

Data rates up to 2 Mbps in the initial phase,

Maximum use of Intelligent Network (IN) capabilities for service development and provisioning,

Global seamless roaming and service delivery across IMT-2000 networks,

Enhanced security and performance

3G

Arc

hit

ec

ture

s

Third-generation mobile communications Dominated by two largely incompatible systems: UMTS and CDMA2000

Universal and seamless communication remains elusive Due to regional, political, and commercial aspects of the mobile

communications business

Third-generation mobile communications Dominated by two largely incompatible systems: UMTS and CDMA2000

Universal and seamless communication remains elusive Due to regional, political, and commercial aspects of the mobile

communications business

2G 2.5G 3G 3.5G1G 4G

AMPS/NTT/NMTGSM/D-AMPS/IS-95/PDC/PHS

GPRS/EDGE/I-mode/WAP

IMT-2000 (W-CDMA/cdma2000)

HDR/1xtremeHSDPA

3G ArchitecturesUniversal Mobile Telecommunications System (UMTS), or 3GPP: One realization of IMT-2000 vision, developed under 3GPP

Significant support in Europe, Japan, and some parts of Asia

System evolved from the 2nd generation Global System for Mobile Communications (GSM). Decision to base 3G specifications on GSM due to:

widespread deployment of networks based on GSM standards

need to preserve backward compatibility

Re-utilization of the large investments made in the GSM networks

Many added capabilities, but the UMTS core network still resembles the GSM network.

CDMA2000 or 3GPP2 system Another realization of the IMT-2000 vision, standardized under 3GPP2

System has evolved from the 2nd generation IS-95 system

Deployed in most of the regions that had IS-95 presence: the United States, South Korea, Belarus, Romania, some parts of Russia, Japan, and China

MWIF Industry forum formed in early 1999 by leading 3G operators, telecommunications

equipment providers, and IP networking equipment providers MWIF ended work continued under the aegis of the Open Mobile Alliance (OMA).

Goal: to develop all-IP mobile network architectures for the core network and RAN as a counterpoint to the 3GPP R4 architecture.

Contains many architectural approaches important for next-generation systems.

3G

Arc

hit

ec

ture

s

Evolution of 3GPP specifications

Multiple input, multiple output antennas

IMS stage 2 (enhancements such as Push to Talk over Cellular(PoC)

WLAN-UMTS interworking integrated operation with Wireless LAN networks

Introduction of HSUPA (High-Speed Uplink Packet Access)

MBMS (Multimedia Broadcast Multicast Service)

Generic Access Network (GAN); The later releases have standardized a GSM/EDGE-based RAN, called GERAN

20043GPP-R6

LTE (Long Term Evolution)

All-IP Network. Release 8 constitutes a reformulation of UMTS as an entirely IP based fourth-generation network.

In progress

(expected

2009)

3GPP-R8

Decreasing latency; Improvements to QoS and real-time applications such as VoIP.

HSPA+ (High Speed Packet Access Evolution)

SIM high-speed protocol

Contactless front-end interface (Near Field Communication for operators to deliver contactless services like Mobile Payments)

EDGE Evolution.

20073GPP-R7

Introduction of IMS

IPv6 introduced in the PS domain; IP transport in UTRAN

Introduction of high-speed downlink packet access (HSDPA)

Introduction of new codec (wideband AMR)

CAMEL phase 4; OSA enhancements

20023GPP-R5

GERAN concept established

Separation of MSC into a MSC server and media gateway for bearer independent CS domain

Streaming media introduced; Multimedia messaging

Added All-IP Core Network features

20013GPP-R4

very strong GSM flavor - the core network design for circuit-switched traffic is very similar to the GSM network

Creation of UTRAN both in FDD and TDD, incorporating a CDMA air interface. Radio Access Network specifications in

Release 99 only include UMTS Radio Access Network (UTRAN) - while alluding to other alternative RANs.

CAMEL phase 3

Location services (LCS)

New codec introduced (narrowband AMR)

20003GPP-R99

Description

3GPP - 3rd Generation Partnership Project

Freeze

Date

3GPP

Release

UM

TS

UMTS Basic Public Land Mobile

Network (PLMN) ConfigurationAccess Networks (AN) Core Networks (CN)

BSS Base Station System

BTS Base Transceiver Station

BSC Base Station Controller

RNS Radio Network System

RNC Radio Network Controller

CN Core Network

MSC Mobile-service Switching Controller

VLR Visitor Location Registor

HLR Home Location Register

3G

Ne

two

rkA

rch

ite

ctu

re:

UM

TS

BTSs connected to the BSC (RNC)

through cable or microwave links

AuC Authentication Server

GMSC Gateway MSC

SGSN Serving GPRS Support Node

GGSN Gateway GPRS Support Node

CS Circuit Switched

HSS Home Subscriber Servers

IMS Internet Multimedia Subsystem

MS Mobile Station

NMS Network Management Subsystem

PS Packet Switched

PLMN infrastructure

Access networks (two AN types, both providing basic radio access capabilities)

Base-station System (BSS) This is the GSM access network

Radio Network Subsystem (RNS) This is based on UMTS, in particular on the Wideband Code Division

Multiple Access (WCDMA) radio link. UMTS provides: higher bandwidth over the air interface

better handoff mechanisms

eg. Soft handover

The CN primarily consists of two domains (which differ in the handling of user data):

circuit-switched (CS) domain dedicated circuit-switched paths for user traffic

real-time and conversational services (eg. voice, video conferencing)

and a packet-switched (PS) domain end-to-end packet data applications (eg. file transfers, Internet

browsing, and e-mail)

Access networks (two AN types, both providing basic radio access capabilities)

Base-station System (BSS) This is the GSM access network

Radio Network Subsystem (RNS) This is based on UMTS, in particular on the Wideband Code Division

Multiple Access (WCDMA) radio link. UMTS provides: higher bandwidth over the air interface

better handoff mechanisms

eg. Soft handover

The CN primarily consists of two domains (which differ in the handling of user data):

circuit-switched (CS) domain dedicated circuit-switched paths for user traffic

real-time and conversational services (eg. voice, video conferencing)

and a packet-switched (PS) domain end-to-end packet data applications (eg. file transfers, Internet

browsing, and e-mail)

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is divided logically as access network (AN) and core network (CN):

Network Architecture DescriptionHome Subscriber Server (HSS)

Core network logical function that consists of different databases required for the 3G systems, including the

Home Location Register (HLR),

Domain Name Service (DNS),

and subscription and security information.

It also provides necessary support to different applications and services running on the network.

The PS domain provides the General Packet Radio Service (GPRS).

There are two types of GPRS support nodes (analogous to the GMSC and MSC)

the Gateway GPRS Support Node (GGSN)

and the Serving GPRS Support Node (SGSN).

maintain the subscription and location information for the mobile stations

handle the users packet traffic and the PS domain-related signaling.

CS domain contains in the core network :

Switching centers that connect the mobile network and the fixed-line networks

(analogous to exchanges in the PSTN) the Mobile Switching Center or MSC

stores the current location area of the MS within a location register called visited location register (VLR).

implements procedures related to handover between the access networks

the Gateway Mobile Switching Center or GMSC

similar in function to the MSC, situated at the border between the mobile network and the external networks

Relies on the HLR for location management, whereas the other MSCs are internal to the network and rely on VLRs that are often collocated with the MSC.

Media Gateway (MGW) handles user traffic, whereas the MSC server deals with

location and handover signaling.

This separation makes the core network somewhat independent of the bearer technology

Similar to the Next-generation Network (NGN) architecture based on a Softswitch developed for fixed networks.

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Network Management Subsystem (NMS),

forms a separate vertical plane.

BSS

Base-Station Controller (BSC) controls one or more Base

Transceiver Stations;

Unlike Node B, each BTS corresponds to one cell.

Mobile Station (MS) - The users terminal, consists of:

mobile equipment (ME) for radio communication

an identity module, which contains information about the user identity.

user switchs to a different device by inserting an identity module.

the network supports two types of identity modules

the subscriber identity module (SIM) used in 2G systems

or the universal SIM (USIM) used in UMTS systems

goes beyond the SIM -acts as execution environment

The IuCS / IuPS interfaces connect all mobiles in the access network to the CS / PS domains of the CN respectively.

RNS

Radio Network Controller (RNC) -controls radio resources in the access network.

provides soft-handoff capability.

Each RNC covers several Node Bs:

A Node B is a logical entity that is essentially equivalent to a base-station transceiver;

Provides physical radio-link connection between the ME and the RNC.

Network Architecture Description (II)

Other components (not part of the basic transport and service network architecture):

mobile location centers (MLC)

number portability databases,

security gateways,

signaling gateways,

network management entities and interfaces.

Typical PLMN layout For the purposes of location management

PLMN divided into several areas of varying scope.

PLMN maintains the location of the mobile node for the purpose of reachability in terms of several location regions

Location areas (LA) which are used for locating the user for CS traffic; each is served by a VLR, and a VLR

may serve several LA.

Routing areas (RA) used for locating the user for PS traffic;

one or more RAs are managed by a SGSN.

The UTRAN Registration Area (URA) smaller than the RA.

contains cells controlled by single RNC

cells are the smallest unit of location.

SGSN (Serving GPRS Support Node) handles the users data traffic, including:

initial authentication and authorization,

admission control,

charging and data collection,

radio resource management,

packet bearer creation and maintenance,

address mapping and translation,

routing and mobility management,

packet compression,

ciphering for transmission over the RAN.

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GGSN often located at the edge of the PS domain

handles packet data traffic to the UMTS network from outside thenetwork and vice versa.

Important role in mobility management, packet routing, encapsulation, and address translation.

The most visible role for the GGSN is to redirect incoming traffic for a mobile station to its current SGSN.

PDP Context

Packet Data Protocol (PDP) context, Encapsulates the association information

between the PS core network and the MS for an active packet session

contains the information necessary to perform the SGSN functions.

Includes information concerning the type of packet data protocol used

associated addresses

addresses of upstream GGSNs

identifiers to lower layer data convergence protocols in the form of access point identifiers,

NSAPI and SAPI, to route the packets to and from the access network.

The GPRS Tunneling Protocol (GTP) is used for carrying traffic between the SGSN and the GGSN

carries control-plane information and user-plane data.

Packet Data Protocol (PDP) context, Encapsulates the association information

between the PS core network and the MS for an active packet session

contains the information necessary to perform the SGSN functions.

Includes information concerning the type of packet data protocol used

associated addresses

addresses of upstream GGSNs

identifiers to lower layer data convergence protocols in the form of access point identifiers,

NSAPI and SAPI, to route the packets to and from the access network.

The GPRS Tunneling Protocol (GTP) is used for carrying traffic between the SGSN and the GGSN

carries control-plane information and user-plane data.

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A user data packet moves over the stack several times before reaching the IP native network. several points at the access network architecture leading to packet segmentation, reassembly, and

retransmissions,

leads to additional delay, adds unjustifiable complexity to the network.

The protocol stack uses GTP to tunnel data in the CN GTP is independent of underlying network protocols

can carry many packet data protocols transparently: X.25, Frame Relay, IP

ends up by carrying only IP due to its immense growth and popularity

two GTP tunnels (tunneling is a problem with all architectures) between the GGSN and the SGSN

between SGSN and the Serving-RNC.

ATM transport all the way from the BTS to the GGSN

IP over ATM AAL2 from the Serving-RNC to the GGSN fixed ATM cell size leading to packet fragmentation, virtual circuit setup delays

Native IP transport over a simple MAC protocol is preferable (technically and commercially).

A user data packet moves over the stack several times before reaching the IP native network. several points at the access network architecture leading to packet segmentation, reassembly, and

retransmissions,

leads to additional delay, adds unjustifiable complexity to the network.

The protocol stack uses GTP to tunnel data in the CN GTP is independent of underlying network protocols

can carry many packet data protocols transparently: X.25, Frame Relay, IP

ends up by carrying only IP due to its immense growth and popularity

two GTP tunnels (tunneling is a problem with all architectures) between the GGSN and the SGSN

between SGSN and the Serving-RNC.

ATM transport all the way from the BTS to the GGSN

IP over ATM AAL2 from the Serving-RNC to the GGSN fixed ATM cell size leading to packet fragmentation, virtual circuit setup delays

Native IP transport over a simple MAC protocol is preferable (technically and commercially).

UMTS Network Architecture Limitations

Transport protocol stack for UMTS network deployment using ATM backbone

Large complexity of the transport protocol stack for packet data in the PS domain in a typical

UMTS network that uses an ATM backbone to interconnect access and core network entities.

UMTS network architecture separation into three domains: CS, PS,and IMS, corresponding roughly to voice, data, and packet-based multimedia services.

relatively easy migration path from 2G to 3G, preserving infrastructure investments

PS domain can be incrementally added to CS, and IMS can be added after that.

network architecture drawback is the duplication of functionality. new types of PS domain network elements (SGSN, GGSN, etc.) are developed to

provide the same functionality (e.g., mobility management) for user traffic with different QoS characteristics

The IMS in UMTS can support real-time services UMTS uses a modified version of SIP

negotiation of communication details (codecs, etc.),

ensure network paths of the required QoS are available before the session starts

provide appropriate charging signaling to prevent service fraud

the modified protocol can require as much as 30 messages exchanged between different network entities

next-generation network should eliminate extraneous interactions, while maintaining security and QoS properties.

UMTS network architecture separation into three domains: CS, PS,and IMS, corresponding roughly to voice, data, and packet-based multimedia services.

relatively easy migration path from 2G to 3G, preserving infrastructure investments

PS domain can be incrementally added to CS, and IMS can be added after that.

network architecture drawback is the duplication of functionality. new types of PS domain network elements (SGSN, GGSN, etc.) are developed to

provide the same functionality (e.g., mobility management) for user traffic with different QoS characteristics

The IMS in UMTS can support real-time services UMTS uses a modified version of SIP

negotiation of communication details (codecs, etc.),

ensure network paths of the required QoS are available before the session starts

provide appropriate charging signaling to prevent service fraud

the modified protocol can require as much as 30 messages exchanged between different network entities

next-generation network should eliminate extraneous interactions, while maintaining security and QoS properties.

UMTS Network Architecture Limitations

3G: Mobile Network CDMA2000

Complex architecture at the core

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CDMA2000 Network Architecture3

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Standard CDMA2000 architecture diagram partitioned into different domains

Traditional PSTN and

cellular service

architecture consisting of

Service Control Proxies

(SCPs), Intelligent

Peripherals, and Service

Nodes

CS domain services based on the Wireless Intelligent Network (WIN) standards WIN similar in nature to the GSM MAP and CAMEL architecture

High-level services implemented in a Service Control Proxy (SCP) - not in MSC. Similarly to CAMEL

Model simplifies Mobile Switching Center (MSC), making service deployment easier

MSC consults the HLR and the SCP during the processing of the call, and the SCP or HLR decide what type of service to provide for a particular call.

Intelligent Peripheral performs simple tasks

eg. collecting digits or speech-to-text conversion

hands over results to SCP for further processing

The Service Transfer Point (STP) a packet switch connecting network components

CS domain services based on the Wireless Intelligent Network (WIN) standards WIN similar in nature to the GSM MAP and CAMEL architecture

High-level services implemented in a Service Control Proxy (SCP) - not in MSC. Similarly to CAMEL

Model simplifies Mobile Switching Center (MSC), making service deployment easier

MSC consults the HLR and the SCP during the processing of the call, and the SCP or HLR decide what type of service to provide for a particular call.

Intelligent Peripheral performs simple tasks

eg. collecting digits or speech-to-text conversion

hands over results to SCP for further processing

The Service Transfer Point (STP) a packet switch connecting network components

CS Domain Services in the

CDMA2000 architecture

WIN components with stand-alone HLR

STP

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Network Architecture: CDMA2000

vs UMTS - similarities & differences The CDMA2000 network has several similarities with the UMTS network:

From a high-level perspective, both have a CS domain and a PS domain

Both support the IMS for Internet multimedia services, Open Service Access (OSA) for

service creation, and service platform for open services

As for for UMTS, the CS domain is identical to the 2G circuit-switched cellular architecture

The CDMA2000 network has several similarities with the UMTS network:

From a high-level perspective, both have a CS domain and a PS domain

Both support the IMS for Internet multimedia services, Open Service Access (OSA) for

service creation, and service platform for open services

As for for UMTS, the CS domain is identical to the 2G circuit-switched cellular architecture

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However, from an architectural perspective, the UMTS and CDMA2000 systems

differ significantly in how they handle packet-switched traffic in the core network.

The CDMA2000 PS domain consists of:

The packet control function (PCF)

PCF technically is a radio access network function, which controls the transmission of packets

between the BSC and the PDSN.

Packet data support node (PDSN),

The access network diverts the packet-switched traffic to the PDSN, which terminates the logical link

control layer for all the packet data

acts as the foreign agent or access router, depending on the network configuration and whether the

network uses IPv4 or IPv6 to support IP-based mobility with Mobile IP (to be studied in more detailed

later in the course for the IP Mobility)

Mobile endpoint home agent (HA)

Interfaces with the PDSN to support mobility using Mobile IP.

An authentication, authorization, and accounting (AAA) function

Interfaces to the PSDN subsystem for performing AAA for packet access

However, from an architectural perspective, the UMTS and CDMA2000 systems

differ significantly in how they handle packet-switched traffic in the core network.

The CDMA2000 PS domain consists of:

The packet control function (PCF)

PCF technically is a radio access network function, which controls the transmission of packets

between the BSC and the PDSN.

Packet data support node (PDSN),

The access network diverts the packet-switched traffic to the PDSN, which terminates the logical link

control layer for all the packet data

acts as the foreign agent or access router, depending on the network configuration and whether the

network uses IPv4 or IPv6 to support IP-based mobility with Mobile IP (to be studied in more detailed

later in the course for the IP Mobility)

Mobile endpoint home agent (HA)

Interfaces with the PDSN to support mobility using Mobile IP.

An authentication, authorization, and accounting (AAA) function

Interfaces to the PSDN subsystem for performing AAA for packet access

MWIF

In comparison with the 3GPP R5 architecture, the MWIF design does not consider the PSTN and focuses only on packet-switched transport.

The MWIF core architecture intended to completely eliminate circuit-switched support

except as a backward compatibility option through a gateway

MWIF RAN architecture is intended to support IP to the base station, instead of ATM as in 3GPP R4.

The MWIF architecture is based entirely on Voice over IP on the core network (after traffic leaves the access network)

there is neither an IU-CS interface nor an MSC in the MWIF design

The MWIF core architecture consists of two parts: A layered functional architecture

A network reference architecture

In comparison with the 3GPP R5 architecture, the MWIF design does not consider the PSTN and focuses only on packet-switched transport.

The MWIF core architecture intended to completely eliminate circuit-switched support

except as a backward compatibility option through a gateway

MWIF RAN architecture is intended to support IP to the base station, instead of ATM as in 3GPP R4.

The MWIF architecture is based entirely on Voice over IP on the core network (after traffic leaves the access network)

there is neither an IU-CS interface nor an MSC in the MWIF design

The MWIF core architecture consists of two parts: A layered functional architecture

A network reference architecture

MWIF Network Architecture

MWIF layered functional architecture (OMA)

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Two cross-layer functional (vertical) areas Operations, administration, management, and provisioning

Security

Four horizontal layers Applications:

third-party applications available through the mobile operators network

Services: applications within the

operators network,

networking support services such as naming and directory services

Control: mobility management,

authorization,

accounting,

real-time media management,

network resource management,

address allocation

Transport: Basic IP routing,

gateway services to access networks

Four horizontal layers Applications:

third-party applications available through the mobile operators network

Services: applications within the

operators network,

networking support services such as naming and directory services

Control: mobility management,

authorization,

accounting,

real-time media management,

network resource management,

address allocation

Transport: Basic IP routing,

gateway services to access networks

Network Reference Architecture Developed from the layered functional

architecture assigns functional entities to network

entities

Design of core network - 68 specific network reference points

act as interfaces between the network entities and outside networks.

OpenRAN functional architecture for a radio

access network based on open, IP-based protocols

IP-based signaling and transport for RANs (instead of ATM and SS7 used in 3G RAN)

separation of the control and data planes

architecture consists of 14 functional entities separated by 27 reference points.

Baseline radio protocol is CDMA

voice over IP over the air not provided, voice over IP terminates at a functional

entity that adapts the IP traffic to the radio (Similarly to 3G networks)

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CDMA2000 & MWIF Network

Architecture LimitationsCDMA2000 Network Architecture

Simpler protocol stack for CDMA2000 than UMTS A data packet does not undergo multiple transformations to reach Internet.

The PDSN uses the Point-to-Point Protocol (PPP) to maintain a link with the mobile station

this forms a link control layer, there is only one logical link control connection between the first hop IP router and the mobile station

Use of Mobile IP combined with AAA functions to support handover(major difference in CDMA2000)

unlike the UMTS network where GTP combined with MAP is used for mobility management.

Edge-based technique for handoff in PS domain, by stretching the PPP tunnel between the old and the new Packet Control

Function (stretchy PPP)

effectively defers the signaling and end-to-end path update between the MS and its correspondent nodes, handling mobility locally.

fairly effective in reducing packet loss during the handover. Protocol model for IP packet data

Normal operation while the MS is stationary


To a large extent, MWIF is the 3G architecture that comes closest to the basis for a Next Generation architecture. Desirable elimination of a CS domain in the core, with an emphasis on packet switching, and IP

The OpenRAN effort takes this to the next logical step, which is IP in the RAN.

MWIF core network architecture designed to be access network independent differentiates it from the UMTS and earlier CDMA2000 system architectures

Access Network Gateway: functional element for the interface of core network to access network, at the periphery of the core network. In principle, allowing an MWIF core to be connected to any of a variety of access networks, including such wired networks as DSL.

The later generation CDMA2000 network and the UMTS network have adopted a similar model.

Drawback: never fully specified, developed, or deployed commercially (only laboratory prototypes developed) Unclear interoperability with legacy 2G and 2.5G systems


To a large extent, MWIF is the 3G architecture that comes closest to the basis for a Next Generation architecture. Desirable elimination of a CS domain in the core, with an emphasis on packet switching, and IP

The OpenRAN effort takes this to the next logical step, which is IP in the RAN.

MWIF core network architecture designed to be access network independent differentiates it from the UMTS and earlier CDMA2000 system architectures

Access Network Gateway: functional element for the interface of core network to access network, at the periphery of the core network. In principle, allowing an MWIF core to be connected to any of a variety of access networks, including such wired networks as DSL.

The later generation CDMA2000 network and the UMTS network have adopted a similar model.

Drawback: never fully specified, developed, or deployed commercially (only laboratory prototypes developed) Unclear interoperability with legacy 2G and 2.5G systems

UMTS Service Architecture

UMTS service classification - a layered structure

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3GPP standardizes service capabilities (not services), which consist of generic bearers

defined by Quality of Service (QoS) parameters such as bandwidth, delay, and symmetry

and the mechanisms needed to realize services, including

the functionality provided by various network elements,

the communication between them,

and the storage of associated data.

3GPP standardizes service capabilities (not services), which consist of generic bearers

defined by Quality of Service (QoS) parameters such as bandwidth, delay, and symmetry

and the mechanisms needed to realize services, including

the functionality provided by various network elements,

the communication between them,

and the storage of associated data.

IP multimedia services deals directly with multimedia

(eg. image and video download and streaming).

Circuit bearer services (at the lowest level) such as circuit-switched transport

Circuit teleservices(CS domain)

consist of simple telephone calls, fax

Supplementary services (operate on the CS domain)

provide enhancements such as call waiting, call forwarding, and three-way calling.

Additional bearer services that can be used by the applications to send different types of content:

Short Message Service (SMS)

Unstructured Supplementary Service Data (USSD)

User-to-User Signaling (UUS)

Non-call-related services are those that do not directly relate to a call in progress,

Eg. notification of voicemail or e-mail message arrival.

Non-call-related value-added services not related to voice calls

offer advanced data capabilities such as e-mail access, web browsing, and file transfer.

Virtual Home Environment (VHE)

service concept

A home environment is defined to each user One or more user profiles are defined and stored

On the move, user profiles can be used to provide a VHE in the visited network.

Availability to users (independently of network or terminal) of a consistent personalized set of services and features

Uniform tools for accessing services and creating services.

user interface and look and feel

VHE is enabled by generic bearers (defined by QoS)

the user profile, referred to as call control (CS, PS, or IMS control)

A home environment is defined to each user One or more user profiles are defined and stored

On the move, user profiles can be used to provide a VHE in the visited network.

Availability to users (independently of network or terminal) of a consistent personalized set of services and features

Uniform tools for accessing services and creating services.

user interface and look and feel

VHE is enabled by generic bearers (defined by QoS)

the user profile, referred to as call control (CS, PS, or IMS control)

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and a collection of service toolkits Specifications of protocols, environments, or APIs for developing services of various

types. Include: User SIM Application Toolkit (USAT)

Mobile Execution Environment (MExE)

Customized Applications for Mobile Network Enhanced Logic (CAMEL)

and Open Service Access (OSA).

3GPP envisions that new toolkits can be added to the 3GPP specifications non-3GPP toolkits also possible

and a collection of service toolkits Specifications of protocols, environments, or APIs for developing services of various

types. Include: User SIM Application Toolkit (USAT)

Mobile Execution Environment (MExE)

Customized Applications for Mobile Network Enhanced Logic (CAMEL)

and Open Service Access (OSA).

3GPP envisions that new toolkits can be added to the 3GPP specifications non-3GPP toolkits also possible

CAMEL

Set of standards that allow an operator to define services over and above GSM or UMTS services

Provide separation of high-level services from basic switching and call processing

Subscriber can roam between switching centers and foreign networks, switching functions in the foreign network interact with service control functions in the users home network.

A CAMEL service residing in the service control function (SCF) is invoked when a trigger contained in the switching function fires.

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SS7 protocol suite

CAMEL is used to provide network intelligence in the UMTS

CAMEL operates using two protocols:

CAMEL Applications Part (CAP)

Similar to the Intelligent Networks (IN) Application Part (INAP) protocol in fixed networks

Mobile Applications Part (MAP).

Application-layer protocol for signaling between mobility service functions, such as the MSC or VLR (Visited Location Register), and control function, such as the HLR.

Used to access as well other functions: Equipment Identity Register, Authentication Centre, Short message service center and Serving GPRS Support Node

Examples of CAMEL Services

Wireless prepaid service Subscriber establishes an account with the service provider and pays before use in order

to obtain service in home and visited networks - a very successful CAMEL service!

No-prefix dialling the number the user dials is the same no matter the country where the call is placed)

Seamless MMS message access from abroad

Examples of CAMEL Services

Wireless prepaid service Subscriber establishes an account with the service provider and pays before use in order

to obtain service in home and visited networks - a very successful CAMEL service!

No-prefix dialling the number the user dials is the same no matter the country where the call is placed)

Seamless MMS message access from abroad

Service Provisioning: Three

Interacting Logical Networks

Interrogating Network needs the mobile users location

information from the HLR in order to deliver a call.

The Home Network, unless the network supports optimal routing

Contains two logical entities: GMSC

gsmSSF: allows GMSC to communicate with the gsmSCF

The gsmSRF corresponds to the IN Intelligent Peripheral, and can play announcements, collect user digits.

Visited Network, where the user is currently located, with 3 logical entities:

MSC and VLR, as in 2G cellular networks

GSM Service Switching Function (gsmSSF) interfaces between the MSC and the gsmSCF.

analogous to the Service Switching Point (SSP) in a fixed IN network,

Home Network of the user, which contains 2 logical entities, as in 2G cellular networks:

The HLR stores the CAMEL Subscription

Information (CSI) - the subscribers location and service profile information,

GSM Service Control Function (gsmSCF)

The execution environment for services analogous to the service control proxy (SCP) in fixed IN net

Stores the service logic.

service control function (SCF)

Mobile Switching Center (MSC)

Gateway Mobile Switching Center (GMSC)

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MExE Service

Environment (MSE)

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MExE is the execution environment in the mobile terminal equipment

In the fixed

network proxy

servers

MExE can support one or more user profiles, storing them in the ME or USIM.

MExE devices are required to support capability negotiation usually takes place before

service commences.

MExEdevices may enter in content negotiation

with the MSE to determine requested /

available form of content

using Hypertext Transport Protocol (HTTP)

or the Wireless Session Protocol (WSP)

MExEdevices may enter in content negotiation

with the MSE to determine requested /

available form of content

using Hypertext Transport Protocol (HTTP)

or the Wireless Session Protocol (WSP)

deliver services to the user

Informs of MSE capabilities on use

MExE devices

can interact to

provide a service.

Informs about MExE resources,

mechanisms, and support

using Composite Capability

/Preference Profiles (CC/PP)

translate content

to enable its

delivery on the

mobile terminal

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ClassmarksCategories of devices defined by 3GPP based on computational capability

Classmark 1 device supporting WAP. Limited input and output facilities.

Classmark 2 a PersonalJava device with the addition of the JavaPhone API.

Classmark 3 based on J2ME Connected Limited Device Configuration and

Mobile Information Device Profile (MIDP) environments

Classmark 4 based on the Common Language Infrastructure (CLI) Compact

Profile

ClassmarksCategories of devices defined by 3GPP based on computational capability

Classmark 1 device supporting WAP. Limited input and output facilities.

Classmark 2 a PersonalJava device with the addition of the JavaPhone API.

Classmark 3 based on J2ME Connected Limited Device Configuration and

Mobile Information Device Profile (MIDP) environments

Classmark 4 based on the Common Language Infrastructure (CLI) Compact

Profile

APIs for Classmark 2

PersonalJava

supports

web content

access and

Java applets

JavaPhone API

allows telephony control,

messaging, and personal

information management

functions, such as address

book and calendar.

USAT The Universal SIM Application Toolkit (USAT)

is an enhancement of the SAT defined for 2G systems

provides mechanisms to allow applications on the USIM to interact with the ME, the user, and USAT servers in the fixed network.

Among the mechanisms provided are: Profile download

Proactive UICC

Data download

Call control

Universal Integrated Circuit Card (UICC) - defined in 3GPP as a physically secure device, like an IC card (or smart card) that can be inserted into terminals.

To access mobile services , it contains SIM/USIM for 2G/3GUM

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OSAOSA - 3GPP adopted the Parlay service framework for 3G

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Application Servers

Open Service Access - three components (Like Parlay)

Applications:

Call control application for call forwarding,

Virtual private network (VPN) application,

or a location-based service.

SCS:

These are abstractions of underlying network functionality.

Applications use network functionality defined around a set of logical Service Capability Features (SCFs), accessed via a language-independent API.

SCFs are encapsulated as Service Capability Servers (SCS).

SCS registers itself with the framework to enable discovery by applications

Applications issue OSA API commands to SCS, including commands to

perform service functions

register to be notified of underlying network events, such as call origination.

Framework:

Applications must utilize the framework to be authenticated and discover the available SCFs before they access to the SCFs.

OSA APIs used by several vendors and carriers


Limitations

Providing portable services across networks and terminals, and a common look and feel to the

user interface

likely to ease and speed the adoption of services, particularly new services (very attractive), but hard

deployment

VHE concept faults to ease and speed the development and deployment of large numbers of innovative

new services.

vital from the point of view of users, service providers and network operators.

Deploying new services rapidly and efficiently requires more flexible and programmable

networks

The 3GPP APIs and toolkits, namely, OSA, CAMEL, MExE, and USAT, are very relevant.

OSA and CAMEL address fixed network programmability

MExE and USAT address terminal programmability

The definitions of MExE and USAT represent a significant step forward from the traditional

notion of programmability in the PSTN, which assumes that terminals have little or no

intelligence, and even from the programmability offered by SAT in GSM.

Providing portable services across networks and terminals, and a common look and feel to the

user interface

likely to ease and speed the adoption of services, particularly new services (very attractive), but hard

deployment

VHE concept faults to ease and speed the development and deployment of large numbers of innovative

new services.

vital from the point of view of users, service providers and network operators.

Deploying new services rapidly and efficiently requires more flexible and programmable

networks

The 3GPP APIs and toolkits, namely, OSA, CAMEL, MExE, and USAT, are very relevant.

OSA and CAMEL address fixed network programmability

MExE and USAT address terminal programmability

The definitions of MExE and USAT represent a significant step forward from the traditional

notion of programmability in the PSTN, which assumes that terminals have little or no

intelligence, and even from the programmability offered by SAT in GSM.

VHE concept


Limitations (II)Programmability in UMTS has significant limitations CAMEL essentially offers only the same level of programmability as IN

There is no formal API and programming services requires specialized languages and tools, as well as a degree of access typically only available to network operators.

MExE Classmark defined in terms of existing, well-known APIs Problem: Classmarks tend to form vertical separators; lack of applications portability between classmarks

MExE taps into an existing application development community and technology without developing a coherent programmability solution.

USAT - the most interesting aspect of UMTS programmability represents a significant potential opportunity for new services as the capabilities of UICC continue to grow.

UICC should be prioritary in the next generation service architecture - does not seem to be the case for 3G.

OSA OSA is at a higher layer of abstraction than CAMEL: spans the CS, PS, and IMS domains. CAMEL limited to CS domain.

APIs are limited as they are network centric, tend to be heavy weight, and do not pay sufficient attention to security for advanced services.

A critical failing - not explicitly modelling users or roles.

OSA APIs (and other UMTS APIs) critical drawback - provide only a single level of abstraction, and access, to network.

No level of protocol programmability to provide further flexibility and possible performance benefits (unlike the JAIN APIs). A system of coherent, well-defined APIs at different levels of abstraction is required.

Service architecture separation into the CS, PS, and IMS domains Not only undesirable from a network architecture point of view, but it is also problematic from a service

point of view.

seems a complex application that requires coordinated features from multiple domains and will be more difficult to develop in a coherent manner.

Programmability in UMTS has significant limitations CAMEL essentially offers only the same level of programmability as IN

There is no formal API and programming services requires specialized languages and tools, as well as a degree of access typically only available to network operators.

MExE Classmark defined in terms of existing, well-known APIs Problem: Classmarks tend to form vertical separators; lack of applications portability between classmarks

MExE taps into an existing application development community and technology without developing a coherent programmability solution.

USAT - the most interesting aspect of UMTS programmability represents a significant potential opportunity for new services as the capabilities of UICC continue to grow.

UICC should be prioritary in the next generation service architecture - does not seem to be the case for 3G.

OSA OSA is at a higher layer of abstraction than CAMEL: spans the CS, PS, and IMS domains. CAMEL limited to CS domain.

APIs are limited as they are network centric, tend to be heavy weight, and do not pay sufficient attention to security for advanced services.

A critical failing - not explicitly modelling users or roles.

OSA APIs (and other UMTS APIs) critical drawback - provide only a single level of abstraction, and access, to network.

No level of protocol programmability to provide further flexibility and possible performance benefits (unlike the JAIN APIs). A system of coherent, well-defined APIs at different levels of abstraction is required.

Service architecture separation into the CS, PS, and IMS domains Not only undesirable from a network architecture point of view, but it is also problematic from a service

point of view.

seems a complex application that requires coordinated features from multiple domains and will be more difficult to develop in a coherent manner.

CDMA2000 & MWIF

Service Architectures

MWIF Service Architecture

Service architecture not explicitly defined

Implicitly assumed telephony-oriented services can be developed with an e2e approach using SIP signaling

IMS similar to that for UMTS and CDMA2000 is, in principle, supported it can be connected directly to the IP core rather than to a PS domain

Focus of 3G network on the RAN and core network.

Seamless interoperability with Internet using IP as the core base protocol

MWIF Service Architecture

Service architecture not explicitly defined

Implicitly assumed telephony-oriented services can be developed with an e2e approach using SIP signaling

IMS similar to that for UMTS and CDMA2000 is, in principle, supported it can be connected directly to the IP core rather than to a PS domain

Focus of 3G network on the RAN and core network.

Seamless interoperability with Internet using IP as the core base protocol

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CDMA2000 Service Architecture

Similar to that of UMTS same underlying domains (CS and PS) and adopts the IMS for multimedia

services

3GPP2 also adopts the principles of the VHE, although in a slightly different form.

Key differences between the UMTS and CDMA2000 at the network architecture, particularly in the air interface and RAN design.

CDMA2000 Service Architecture

Similar to that of UMTS same underlying domains (CS and PS) and adopts the IMS for multimedia

services

3GPP2 also adopts the principles of the VHE, although in a slightly different form.

Key differences between the UMTS and CDMA2000 at the network architecture, particularly in the air interface and RAN design.

Limitations of 3G Architectures

Overview

UMTS network architecture duplicates functionality for

different traffic types,

has a complex protocol stack,

uses a modified SIP protocol that is relatively heavy weight.

UMTS and CDMA2000 service architectures

lack a coherent programmability solution

Need better logical separation of networking functions and protocols at the level of the network architecture

On the service architecture, provision for developing and deploying new services

Overview

UMTS network architecture duplicates functionality for

different traffic types,

has a complex protocol stack,

uses a modified SIP protocol that is relatively heavy weight.

UMTS and CDMA2000 service architectures

lack a coherent programmability solution

Need better logical separation of networking functions and protocols at the level of the network architecture

On the service architecture, provision for developing and deploying new services

Architecture Limitations

Motivations for an all-IP network

Enable large variety of innovative and commercially lucrative services

Simpler protocol stack

Motivations for an all-IP network

Enable large variety of innovative and commercially lucrative services

Simpler protocol stack

Next Generation Architectures

The All-IP Model

PSTN services

Integrated or centralized business model

Same entity (government body, company) is: the network operator,

the service developer,

and the service provider to the end user.

Service development by specialized personnel in closed environments, using specialized languages and tools.

IP networks low entry barriers into the market

open and rapid proliferation of knowledge

Large number of creative programmers and entrepreneurs available,

possibility of developing advanced services at the edge of the network

Greater availability of

personnel, tools, and

support for application

development for IP

networks than for the

PSTN.

IP technical simplicity

IP acts as a unifying abstraction less complex protocol stack

Hides heterogeneity of protocols and networks below it

Easier application development for IP networks

Rapid development and

deployment of a large

number of Internet

applications, competing

with the PSTNs current

or potential markets (eg.

e-mail, messaging,

content distribution)

Other factor into consideration - potentially smaller costs of IP networks IP NEs (routers, firewalls, and proxies): economies of scale compared to fixed and mobile PSTN components

network elements not necessarily the dominant costs of a network

Larger costs potentially from OA&M

For mobile networks, the connection costs from base stations to the core fixed network (the backhaul),

Other factor into consideration - potentially smaller costs of IP networks IP NEs (routers, firewalls, and proxies): economies of scale compared to fixed and mobile PSTN components

network elements not necessarily the dominant costs of a network

Larger costs potentially from OA&M

For mobile networks, the connection costs from base stations to the core fixed network (the backhaul),

All-IP Network - Barriers

Development of open standard APIs (eg. JAIN, Parlay) APIs provide programming abstractions that operate across

PSTN, ATM, and IP networks. underlying transport network less important

JAIN APIs have been developed for individual protocol applications get improved performance / fine-grained control can

in exchange for increased programming complexity

JAIN APIs not only for IPs, such as SIP, but also for SS7 protocols, such as ISUP and TCAP.

IP protocols - Number, Complexity, and Size grows rapidly, reaching traditional PSTN protocols.

Standardization delay increasingly longer (approaching traditional PSTN protocols

delays)

Development of open standard APIs (eg. JAIN, Parlay) APIs provide programming abstractions that operate across

PSTN, ATM, and IP networks. underlying transport network less important

JAIN APIs have been developed for individual protocol applications get improved performance / fine-grained control can

in exchange for increased programming complexity

JAIN APIs not only for IPs, such as SIP, but also for SS7 protocols, such as ISUP and TCAP.

IP protocols - Number, Complexity, and Size grows rapidly, reaching traditional PSTN protocols.

Standardization delay increasingly longer (approaching traditional PSTN protocols

delays)

Rise of Internet applications

Needed efficient integration of telecommunications network with the Internet for access to / interact with internet applications via the network

3.5G

Middleware API

offers applications, with the required security and billing credentials, access to higher-layer functions, such as:

access to overlay network elements for content distribution or multicast,

location and other context information servers,

security certificate authorities.

Middleware API

offers applications, with the required security and billing credentials, access to higher-layer functions, such as:

access to overlay network elements for content distribution or multicast,

location and other context information servers,

security certificate authorities.

The Second Waist and

Programmability Independent software vendors and

system integrators to develop new applications and solutions (similarly to PC industry)

Next generation networks defined byavailability of innovative applications

Programmable IP-based next generation network

Powerful and well-defined APIs for rapid application development.

Second waist at the interface between applications and the middleware. It must

hide the heterogeneity of the protocol stack and software layers between the application and the IP waist.

offer a high level of abstraction and flexibility than the core network API

Web services, including WSDL,

SOAP, and UDDI

securilly protect overall network

allow billing for network use

Independent software vendors and system integrators to develop new applications and solutions (similarly to PC industry)

Next generation networks defined byavailability of innovative applications

Programmable IP-based next generation network

Powerful and well-defined APIs for rapid application development.

Second waist at the interface between applications and the middleware. It must

hide the heterogeneity of the protocol stack and software layers between the application and the IP waist.

offer a high level of abstraction and flexibility than the core network API

Web services, including WSDL,

SOAP, and UDDI

securilly protect overall network

allow billing for network use

Layered APIs

third-party

applications

dominating in

terms of traffic

and revenues

Core network API

provides interfaces for internet signaling and coordination protocols

from the network, transport, and session layers (i.e.,layers 35) of the OSI Reference model (such as SIP, Mobile IP).

allows applications with security and billing authority to obtain fine-grained control over core network resources and functions.

Core network API

provides interfaces for internet signaling and coordination protocols

from the network, transport, and session layers (i.e.,layers 35) of the OSI Reference model (such as SIP, Mobile IP).

allows applications with security and billing authority to obtain fine-grained control over core network resources and functions.

Conclusions

3G architectures significant limitations both at the level of network and service

architectures.

all-IP architecture is the best candidate for developing innovative and lucrative services.

evolution of intelligence in all portions of the cellular architecture.

Key enablers for the Next Generation architecture mobility management

Security and cryptography,

network programmability

support for value-added services

For Next Generation networks, the key features and

differentiators will lie at the service architecture levels.For Next Generation networks, the key features and

differentiators will lie at the service architecture levels.

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