Post on 21-Sep-2018
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica1
Redes de ComputadoresRedes de Computadores
Redes Moveis e
Mobilidade
Artur Arsenio
Redes de Computadores 2010/2011
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
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica3 Redes Moveis e Mobilidade
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
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica4 Redes Moveis e Mobilidade
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
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica5 Redes Moveis e Mobilidade
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
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica6 Redes Moveis e Mobilidade
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
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica7 Redes Moveis e Mobilidade
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
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica8 Redes Moveis e Mobilidade
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)
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica9 Redes Moveis e Mobilidade
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
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica10 Redes Moveis e Mobilidade
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
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica11 Redes Moveis e Mobilidade
CDMA: Codificao/Descodificao
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica12 Redes Moveis e Mobilidade
CDMA: Interferncia entre 2 emissores
Sequncias de chippingmutuamente ortogonais entre si
Ckm. cjm = 0, se i,j diferentes
Ckm. ckm = M
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica13 Redes Moveis e Mobilidade
Caracteristicas de Redes sem Fios Reviso
Redes sem Fios
Caracteristicas de Redes sem Fios CDMA
IEEE 802.11 wireless LANs (wi-fi)
Redes Celulares arquitectura
standards (e.g., GSM)
Mobilidade
Principios endereamento e encaminhamento
para utilizadores mveis
Mobilidade IP
Mobilidade em Redes Celulares
Mobilidade e Protocolos de alto nvel
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
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica14 Redes Moveis e Mobilidade
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
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica15 Redes Moveis e Mobilidade
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
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica16 Redes Moveis e Mobilidade
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
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica17 Redes Moveis e Mobilidade
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
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica18 Redes Moveis e Mobilidade
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
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica19 Redes Moveis e Mobilidade
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
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica20 Redes Moveis e Mobilidade
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
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica21 Redes Moveis e Mobilidade
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
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica22 Redes Moveis e Mobilidade
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
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica23 Redes Moveis e Mobilidade
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
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica24 Redes Moveis e Mobilidade
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
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica25 Redes Moveis e Mobilidade
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
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica26 Redes Moveis e Mobilidade
IEEE 802.11 wireless LANs (wi-fi) Reviso
Redes sem Fios
Caracteristicas de Redes sem Fios CDMA
IEEE 802.11 wireless LANs (wi-fi)
Redes Celulares arquitectura
standards (e.g., GSM)
Mobilidade
Principios endereamento e encaminhamento para
utilizadores mveis
Mobilidade IP
Mobilidade em Redes Celulares
Mobilidade e Protocolos de alto nvel
IEEE 802.11 LAN
Arquitectura
Canais, Associao
IEEE 802.11: Acesso
mltiplo
CSMA/CA IEEE 802.11
Evitar Colises: troca de
RTS-CTS
Formato da Trama 802.11
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
Formato da Trama 802.11
Endereamento
Mobilidade dentro da
mesma subrede
802.15: wireless personal
area network (Piconet)
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica27 Redes Moveis e Mobilidade
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
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica28 Redes Moveis e Mobilidade
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
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica29 Redes Moveis e Mobilidade
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
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica30 Redes Moveis e Mobilidade
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
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica31 Redes Moveis e Mobilidade
Redes Celulares - Reviso
Redes sem Fios
Caracteristicas de Redes sem Fios CDMA
IEEE 802.11 wireless LANs (wi-fi)
Redes Celulares arquitectura
standards (e.g., GSM)
Mobilidade
Principios endereamento e encaminhamento para
utilizadores mveis
Mobilidade IP
Mobilidade em Redes Celulares
Mobilidade e Protocolos de alto nvel
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
Artur Arsenio
Redes de Computadores 2010/2011
Departamento de Engenharia Informtica32 Redes Moveis e Mobilidade
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.
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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
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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
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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
MWIF Network Architecture
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
MWIF Network Architecture
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)
MExEU
MT
S S
erv
ice
Arc
hit
ec
ture
MExE Service
Environment (MSE)
ME
xE
clie
nt
ME
xE
clie
nt
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
MExEU
MT
S S
erv
ice
Arc
hit
ec
ture
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
TS
Se
rvic
eA
rch
ite
ctu
re
OSAOSA - 3GPP adopted the Parlay service framework for 3G
UM
TS
Se
rvic
eA
rch
ite
ctu
re
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
UMTS Service Architecture
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
UMTS Service Architecture
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
3G
Se
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ite
ctu
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:
MW
IF &
CD
MA
20
00
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.