1. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica1Redes de ComputadoresRedes de ComputadoresRedes Moveis eMobilidade

2. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica2 Redes Moveis e MobilidadeRedes Moveis e MobilidadeRedes sem FiosCaracteristicas de Redes sem Fios CDMAIEEE 802.11 wireless LANs (wi-fi)Redes Celulares arquitectura standards (e.g., 3G)MobilidadePrincipios endereamento e encaminhamento para utilizadores mveisMobilidade IPMobilidade em Redes CelularesMobilidade e Protocolos de alto nvelSegue Capitulo 6 do livro de J.F Kurose e K.W. Ross 3. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica3 Redes Moveis e MobilidadeInfra-estruturada redeEstao baseLigada tipicamente a rede com fioResponsvel pela comunicaoentre os hosts mveis da sua rea eos hosts das redes infraestruturadase.g., torres celulares e pontos deacesso 802.11Ligao sem fioUsado para ligar osdispositivos mveis sestaes baseControlado por protocolosde mltiplo acessoVrias taxas de transmissoe distncias mximasHosts sem fioLaptop, PDA, telefone IPExecutam AplicaesPodem ser mveis ou no sem fio nem sempresignifica mobilidadeElementos de uma rede sem fios 4. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica4 Redes Moveis e Mobilidade384 Kbps56 Kbps54 Mbps5-11 Mbps1 Mbps802.15802.11b802.11{a,g}IS-95 CDMA, GSMUMTS/WCDMA, CDMA2000.11 p-to-p link2G3GIndoor10 30mOutdoor50 200mMid rangeoutdoor200m 4KmLong rangeoutdoor5Km 20KmCaractersticas das normas dealgumas redes sem fios 5. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica5 Redes Moveis e MobilidadeInfra-estruturada redeLigao InfraestruturaEstao base liga osdispositivos mveis na redecom fiohandoff: dispositivo mvelmuda de estao base,ligando-se nova rede comfioModo de Ligao: Infraestrutura 6. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica6 Redes Moveis e MobilidadeModo Ad hocno existem estaes basens podem transmitir paraoutros somente dentro de umadeterminada coberturans organizam-se em rede e oencaminhamento s pode serfeito entre elesModo de Ligao: Ad hocModo HibridoRedes ad hoc ligadas infraestrutura derede atravs de um ponto de acesso 7. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica7 Redes Moveis e MobilidadeDiferenas para as ligaes com fios: Diminuio da potncia do sinal: sinais de rdio sofremmaior atenuao ao longo do caminho (path loss) Interferncia de outras fontes: frequncias normalizadaspara redes sem fios (e.g. 2.4 GHz) so partilhadas poroutros dispositivos (e.g. telefone)motores e outras fontes tambm interferem Propagao multicaminho (multipath): sinal de rdioreflectido por vrios obstculos terrestres, chegando aodestino com pequenas diferenas de tempo Faz da comunicao sobre uma ligao sem fios (mesmoponto a ponto) muito mais difcilCaractersticas das Ligaes sem Fios 8. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica8 Redes Moveis e MobilidadePropagao multicaminho (multipath)Caracteristicas de propagaovariam com o tempoSinais chegam de vrioscaminhos ao receptor com nveisde potncia diferentes e tempos de chegada (atrasos)tambm diferentesOs efeitos de multipath incluem Interferncia constructiva edestructiva Deslocamento da fase (phaseshifting) do sinal(causa o Rayleigh fading) 9. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica9 Redes Moveis e MobilidadeA existncia de vrios emissores e receptores sem fioscria problemas adicionais para alm do mltiplo acessoABCB, A escutam-se um ao outroB, C escutam-se um ao outroA, C no se podem escutar um ao outro A e C no prevem uma interf. em BA B CAs signalstrengthspaceCs signalstrengthAtenuao do sinalCaractersticas das redes sem fiosProblema do terminal escondido 10. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica10 Redes Moveis e MobilidadeCDMA (Mltiplo Acesso por Diviso por Cdigo): explora esquema decodificao 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 rdiointerferncia entre duas trajectrias do mesmo sinal; e.g. o directo e por reflexoCdigo 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 prpriasequncia 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 simultneocom um mnimo de interferncia , as sequncias de chipping devem ser mutuamenteortogonais entre si (i.e., produto interno = 0)Sinal codificado = (sinal original) X (sequncia chipping)Descodificao: produto interno (soma dos produtos por componente) dosinal codificado pela seq. de chippingCDMA: Partio do Canal 11. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica11 Redes Moveis e MobilidadeCDMA: Codificao/Descodificao 12. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica12 Redes Moveis e MobilidadeCDMA: Interferncia entre 2 emissoresSequncias de chippingmutuamente ortogonaisentre siCkm. cjm = 0, se i,j diferentesCkm. ckm = M 13. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica13 Redes Moveis e MobilidadeCaracteristicas de Redes sem Fios RevisoRedes sem FiosCaracteristicas de Redes sem Fios CDMAIEEE 802.11 wireless LANs (wi-fi)Redes Celulares arquitectura standards (e.g., GSM)MobilidadePrincipios endereamento e encaminhamentopara utilizadores mveisMobilidade IPMobilidade em Redes CelularesMobilidade e Protocolos de alto nvelElementos da rede sem fiosCaractersticas das normasde algumas redes sem fiosModo de Ligao: InfraestruturaAd hocCaractersticas das ligaese redes sem fiosCDMAPartio do CanalCodificao / DescodificaoCDMAInterferncia entre 2emissores CDMAElementos da rede sem fiosCaractersticas das normasde algumas redes sem fiosModo de Ligao: InfraestruturaAd hocCaractersticas das ligaese redes sem fiosCDMAPartio do CanalCodificao / DescodificaoCDMAInterferncia entre 2emissores CDMA 14. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica14 Redes Moveis e MobilidadeIEEE 802.11 Wireless LAN802.11bDirect Sequence SpreadSpectrum (DSSS) nacamada fisicatodos os hosts usam omesmo cdigo dechipping2.4-2.485 GHzunlicensed radiospectrumEspectro de frequnciasde fornos microondas etelefones 2.4GHzat 11 Mbps802.11a 5.1-5.8 GHz range at 54 Mbps Alcane de distncias mais curtas sofrem mais interferncias multipath802.11g 2.4-2.485 GHz range at 54 MbpsTodos usam CSMA/CA para acesso multiploSuportam redes com estaes base e ad-hocCapacidade de reduzir ritmo de transmissopara atingir distncias maiores 15. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica15 Redes Moveis e MobilidadeBSS 1BSS 2Internethub, switchou routerAPAPIEEE 802.11 LAN - ArquitecturaUm host sem fios comunica com aestao base estao base = access point (AP) AP contm MAC nico para a suainterface de rede sem fiosRede residencial tpica contm um AP, um router, e ummodem cabo ou ADSL (ou umterminal ptico)Basic Service Set (BSS) (clula) no modo infraestruturado contm:Hosts sem fiosaccess point (AP) no modo ad hoc: somente hostssem fios 16. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica16 Redes Moveis e Mobilidade802.11: Canais, Associao802.11b: o espectro 2.4GHz-2.485GHz (85MHz) dividido em 11 canais defrequncias 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 APvizinho!No h sobreposio entre 2 canais estiverem separados por 4 ou + canaisCanais 1,6 e 11 nico conjunto de 3 canais no sobrepostoshost: deve descobrir APs dsponiveis, e ser associado com um AP Varre todos os canais, escuta tramas de sinalizao que contm a identificaodos APs (SSID Service Set IDentifier) e o endereo MAC Selecciona um AP para se associar Pode realizar autenticao, exemplo: host comunica com servidor de autenticaousando 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 17. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica17 Redes Moveis e MobilidadeEvitar colises (CSMA/CA): 2 ou mais ns a transmitir ao mesmo tempo802.11: usa o CSMA Acesso mltiplo por deteco de portadora escuta o meio antes de transmitir para no colidir com outras transmisses em andamento802.11: no realiza deteco de coliso Dificuldade em receber (escutar colises) quando est a transmitir devido fraqueza daenergia dos sinais recebidos (fading) No pode escutar todas as colises: e.g. terminal escondido, fadingABCA B Cfora dosinal de Aespaofora dosinal de CIEEE 802.11: Acesso mltiplo 18. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica18 Redes Moveis e MobilidadeProtocolo MAC do CSMA/CA IEEE 802.11Emissor 802.111 se o canal estiver livre, espera um pequeno tempo(Distributed Inter-Frame Space - DIFS) e ento transmite todaa trama (no h deteco de coliso)2 se o canal estiver ocupado entoi. inicia um tempo de backoff aleatrioii. faz contagem regressiva enquanto o canal estiver livrei.Se perceber que canal est ocupado, para contagemiii. transmite quando o tempo expirar, e fica espera de ACKiv. se no chegar um ACK, aumenta o intervalo de backoff erepete o passo 2Receptor 802.11- se a trama recebida estiver OKenvia ACK depois de esperar um SIFS - Short Inter-FrameSpacing (ACK devido ao problema do terminal escondido)sender receiverDIFSdataSIFSACK 19. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica19 Redes Moveis e MobilidadeIdeia: permitir ao emissor reservar o canal ao invs de realizar um acessoaleatrio 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 asestaes ao seu alcance (inclusive o AP) os pacotes RTS podem ainda colidir uns com os outros, mas comoeles so pequenos, no causam longos atrasosAP envia um pacote clear-to-send (CTS) para todas as estaes queesto ao seu alcance, em resposta ao RTSEmissor transmite a trama de dados Outras estaes bloqueiam as suas emissesEvita completamente as colises de longas tramasde dados usando pequenos pacotes de reserva!IEEE 802.11: Evitar ColisesAPH1 H2 20. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica20 Redes Moveis e MobilidadeEvitar Colises: troca de RTS-CTSAPA BtempoRTS(A)RTS(A)CTS(A) CTS(A)DATA (A)ACK(A) ACK(A)RTS(B)Coliso de RTSsOrigem DestinoTodos os outros nsbloqueio bloqueio 21. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica21 Redes Moveis e Mobilidadeframecontroldurationaddress1address2address4address3payload CRC2 2 6 6 6 2 6 0 - 2312 4seqcontrolFormato da Trama 802.11Address 2: endereo MACdo host sem fios ou do APa emitir a tramaAddress 1: endereo MACdo host sem fios ou do APque vai receber a tramaSe pacote vem de host sem fios,ento contm MAC do APAddress 3: endereo MAC da interfacedo router ao qual o AP est ligadoAddress 4:usado somenteno modo ad hocBytesTypeRelembrar: Trama EthernetTipicamente detagramaIP ou pacote ARPErros em bits maiscomuns nas redessem fios 22. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica22 Redes Moveis e MobilidadeInternetrouterAPH1 R1AP MAC addr H1 MAC addr R1 MAC addraddress 1 address 2 address 3Trama 802.11R1 MAC addr AP MAC addrdest. address source addressTrama 802.3 (ethernet)Uma das principais funesde um AP converter umatrama 802.11 para umatrama ethernet e vice-versaTrama 802.11: Endereamento 23. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica23 Redes Moveis e Mobilidadeframecontroldurationaddress1address2address4address3payload CRC2 2 6 6 6 2 6 0 - 2312 4seqcontrolTypeFromAPSubtypeToAPMorefragWEPMoredataPowermgtRetry RsvdProtocolversion2 2 4 1 1 1 1 1 11 1tempo 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, quemudam conforme o modo de uso infraestruturaou ad-hoc, e do emissor ser um host ou APTrama 802.11Bytesbits 24. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica24 Redes Moveis e Mobilidadehub orswitchAP 2AP 1H1 BBS 2BBS 1router802.11- Mobilidade dentro da mesma subredeH1 permanece na mesma subrede:endereo IP pode permanecer omesmo (hub ou switch)Switch: qual o AP que est associadocom H1?Self-learning: switches montamas suas tabelas de formaautomatica, mas no esto aptos alidar com mobilidade excessiva.Existe um par (peer) entre oendereo da sua interface e H1Soluo: AP2 envia em broadcastuma trama ethernet com oendereo fonte de H1 logo depoisda associao 25. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica25 Redes Moveis e MobilidadeMRadio decoberturaSSSPPPPMSMaster deviceSlave deviceParked device (inactive)P802.15: wireless personal area network(Piconet)Dispositivos separados por, no mximo, 10 m de dimetroSubstitui dispositivos com fios por dispositivos sem fios(ratos, teclados, headphones)ad hoc: sem infraestruturaMestre-escravo: Mestre pode emitir em cada time slot impar Escravos solicitam permisso para emitir ao mestre =>Mestre fornece permissoDispositivos parked : no podem transmitir at o seu estadoser 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, pormpseudo-aleatria Taxa de transmisso at 721 kbps 26. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica26 Redes Moveis e MobilidadeIEEE 802.11 wireless LANs (wi-fi) RevisoRedes sem FiosCaracteristicas de Redes sem Fios CDMAIEEE 802.11 wireless LANs (wi-fi)Redes Celulares arquitectura standards (e.g., GSM)MobilidadePrincipios endereamento e encaminhamento parautilizadores mveisMobilidade IPMobilidade em Redes CelularesMobilidade e Protocolos de alto nvelIEEE 802.11 LANArquitecturaCanais, AssociaoIEEE 802.11: AcessomltiploCSMA/CA IEEE 802.11Evitar Colises: troca deRTS-CTSFormato da Trama 802.11EndereamentoMobilidade dentro damesma subrede802.15: wireless personalarea network (Piconet)IEEE 802.11 LANArquitecturaCanais, AssociaoIEEE 802.11: AcessomltiploCSMA/CA IEEE 802.11Evitar Colises: troca deRTS-CTSFormato da Trama 802.11EndereamentoMobilidade dentro damesma subrede802.15: wireless personalarea network (Piconet) 27. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica27 Redes Moveis e Mobilidadeliga celulas s redes de rea alargadagere o estabelecimento de camadasgere a mobilidadeMSCMobileSwitchingCenterPublictelephonenetwork, andInternetMobileSwitchingCentercobre regiogeograficabase station (BS)anloga ao AP 802.11utilizadores mveisligam-se rede atravsda BSinterface-ar:protocolos de camadafisica e lgica entre odispositivo mvel e a BScelulawired networkComponentes da Arquitectura deRedes Celulares 28. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica28 Redes Moveis e MobilidadeRedes Celulares: the first hopDuas tecnicas parapartilhar o espectro defrequncias radiomobile-to-BSFDMA/TDMAcombinado: dividirespectro em canais defrequncia, e dividircada canal em parcelas(slots) de tempoCDMA: code divisionmultiple accessfrequencybandstime slots 29. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica29 Redes Moveis e MobilidadeStandards para Tecnologia Celular:Breve Perspectiva2.5 G systems: canais de sinais de voz e dadosExtenses do 2GGeneral 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 384KCDMA-2000 (phase 1) evoluiu do IS-953G systems: voz/dados/videoUniversal Mobile Telecommunications Service(UMTS) Evoluo do GSM, mas usando CDMACDMA-20002G systems: canais parasinais de vozIS-136 TDMA: usocombinado de FDMA/TDMA(na America do Norte)GSM (global system formobile communications): usocombinado FDMA/TDMAIS-95 CDMA: code divisionmultiple access 30. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica30 Redes Moveis e MobilidadeUMTS 3G Network ArchitectureCS DomainCS (CircuitSwitched)DomainCS (CircuitSwitched)DomainBSS /RNSBSS(BaseStationSystem)/RNS(RadioNetworkSystem)......HSS(Home SubscriberServers)HSS(Home SubscriberServers)PS DomainPS (PacketSwitched)DomainPS (PacketSwitched)DomainMS (Mobile Station)MS (Mobile Station)MSApplicationsandServicesNMS(Network ManagementSubsystem)NMS(Network ManagementSubsystem)IMS(InternetMultimediaSubsystem)IMS(InternetMultimediaSubsystem)AccessNetworkCoreNetworkAccess Network Core Network 31. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica31 Redes Moveis e MobilidadeRedes Celulares - RevisoRedes sem FiosCaracteristicas de Redes sem Fios CDMAIEEE 802.11 wireless LANs (wi-fi)Redes Celulares arquitectura standards (e.g., GSM)MobilidadePrincipios endereamento e encaminhamento parautilizadores mveisMobilidade IPMobilidade em Redes CelularesMobilidade e Protocolos de alto nvelComponentes daArquitectura de RedesCelularesPartilha do espectro defrequncias em redescelularesRedes Celulares: thefirst hopStandards paraTecnologia Celular:Breve PerspectivaComponentes daArquitectura de RedesCelularesPartilha do espectro defrequncias em redescelularesRedes Celulares: thefirst hopStandards paraTecnologia Celular:Breve Perspectiva 32. Artur ArsenioRedes de Computadores 2010/2011Departamento de Engenharia Informtica32 Redes Moveis e MobilidadeAnexoArquitecturas 3G paraRedes Mveis Celulares(em Ingls) 33. 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 (anddemanded 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 (anddemanded by) usersNext 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 billablemanner. 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 billablemanner. 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) 34. The Vision for Third-generation International Telecommunications Unions (ITU) International MobileTelecommunications (IMT-2000) vision Common spectrum worldwide (1.82.2 GHz band) Support for multiple radio environments (including cellular, satellite, cordless, andlocal area networks) integration of satellite and terrestrial systems to provide global coverage. Wide range of telecommunications services (voice, data, multimedia, and theInternet), 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 andprovisioning, Global seamless roaming and service delivery across IMT-2000 networks, Enhanced security and performance International Telecommunications Unions (ITU) International MobileTelecommunications (IMT-2000) vision Common spectrum worldwide (1.82.2 GHz band) Support for multiple radio environments (including cellular, satellite, cordless, andlocal area networks) integration of satellite and terrestrial systems to provide global coverage. Wide range of telecommunications services (voice, data, multimedia, and theInternet), 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 andprovisioning, Global seamless roaming and service delivery across IMT-2000 networks, Enhanced security and performance3GArchitectures 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 mobilecommunications 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 mobilecommunications business2G 2.5G 3G 3.5G1G 4GAMPS/NTT/NMTGSM/D-AMPS/IS-95/PDC/PHSGPRS/EDGE/I-mode/WAPIMT-2000 (W-CDMA/cdma2000)HDR/1xtremeHSDPA 35. 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, SouthKorea, Belarus, Romania, some parts of Russia, Japan, and ChinaMWIF Industry forum formed in early 1999 by leading 3G operators, telecommunicationsequipment 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 acounterpoint to the 3GPP R4 architecture. Contains many architectural approaches important for next-generation systems.3GArchitectures 36. Evolution of 3GPP specificationsMultiple input, multiple output antennasIMS stage 2 (enhancements such as Push to Talk over Cellular(PoC)WLAN-UMTS interworking integrated operation with Wireless LAN networksIntroduction 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 GERAN20043GPP-R6LTE (Long Term Evolution)All-IP Network. Release 8 constitutes a reformulation of UMTS as an entirely IP based fourth-generation network.In progress(expected2009)3GPP-R8Decreasing latency; Improvements to QoS and real-time applications such as VoIP.HSPA+ (High Speed Packet Access Evolution)SIM high-speed protocolContactless front-end interface (Near Field Communication for operators to deliver contactless services like Mobile Payments)EDGE Evolution.20073GPP-R7Introduction of IMSIPv6 introduced in the PS domain; IP transport in UTRANIntroduction of high-speed downlink packet access (HSDPA)Introduction of new codec (wideband AMR)CAMEL phase 4; OSA enhancements20023GPP-R5GERAN concept establishedSeparation of MSC into a MSC server and media gateway for bearer independent CS domainStreaming media introduced; Multimedia messagingAdded All-IP Core Network features20013GPP-R4very strong GSM flavor - the core network design for circuit-switched traffic is very similar to the GSM networkCreation of UTRAN both in FDD and TDD, incorporating a CDMA air interface. Radio Access Network specifications inRelease 99 only include UMTS Radio Access Network (UTRAN) - while alluding to other alternative RANs.CAMEL phase 3Location services (LCS)New codec introduced (narrowband AMR)20003GPP-R99Description3GPP - 3rd Generation Partnership ProjectFreezeDate3GPPReleaseUMTS 37. UMTS Basic Public Land MobileNetwork (PLMN) ConfigurationAccess Networks (AN) Core Networks (CN)BSS Base Station SystemBTS Base Transceiver StationBSC Base Station ControllerRNS Radio Network SystemRNC Radio Network ControllerCN Core NetworkMSC Mobile-service Switching ControllerVLR Visitor Location RegistorHLR Home Location Register3GNetworkArchitecture:UMTSBTSs connected to the BSC (RNC)through cable or microwave linksAuC Authentication ServerGMSC Gateway MSCSGSN Serving GPRS Support NodeGGSN Gateway GPRS Support NodeCS Circuit SwitchedHSS Home Subscriber ServersIMS Internet Multimedia SubsystemMS Mobile StationNMS Network Management SubsystemPS Packet Switched 38. 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 DivisionMultiple 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 thehandling 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, Internetbrowsing, 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 DivisionMultiple 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 thehandling 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, Internetbrowsing, and e-mail)3GNetworkArchitecture:UMTSis divided logically as access network (AN) and core network (CN): 39. Network Architecture DescriptionHome Subscriber Server (HSS) Core network logical function that consists ofdifferent 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 differentapplications 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 theGMSC and MSC) the Gateway GPRS Support Node (GGSN) and the Serving GPRS Support Node (SGSN).maintain the subscription and location information for the mobilestationshandle the users packet traffic and the PS domain-related signaling. CS domain contains in the core network : Switching centers that connect the mobile network andthe fixed-line networks (analogous to exchanges in the PSTN) the Mobile Switching Center or MSC stores the current location area of the MS within alocation register called visited location register (VLR). implements procedures related to handover betweenthe access networks the Gateway Mobile Switching Center or GMSC similar in function to the MSC, situated at the borderbetween the mobile network and the externalnetworks Relies on the HLR for location management,whereas the other MSCs are internal to the networkand rely on VLRs that are often collocated with theMSC. Media Gateway (MGW) handles user traffic, whereas the MSC server deals withlocation and handover signaling. This separation makes the core network somewhatindependent of the bearer technology Similar to the Next-generation Network (NGN) architecturebased on a Softswitch developed for fixed networks. 40. 3GNetworkArchitecture:UMTSNetwork Management Subsystem (NMS),forms a separate vertical plane.BSS Base-Station Controller (BSC) controls one or more BaseTransceiver Stations; Unlike Node B, each BTScorresponds to one cell.Mobile Station (MS) - The usersterminal, consists of: mobile equipment (ME) forradio communication an identity module, whichcontains information about theuser identity. user switchs to a differentdevice by inserting an identitymodule. the network supports two typesof 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 executionenvironmentThe IuCS / IuPS interfaces connect allmobiles in the access network to the CS/ PS domains of the CN respectively.RNS Radio Network Controller (RNC) -controls radio resources in theaccess network. provides soft-handoff capability. Each RNC covers several NodeBs: A Node B is a logical entity thatis essentially equivalent to abase-station transceiver; Provides physical radio-linkconnection between the ME andthe RNC.Network Architecture Description (II) Other components (not part of the basictransport and service networkarchitecture): mobile location centers (MLC) number portability databases, security gateways, signaling gateways, network management entities and interfaces. 41. 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 ofseveral location regions Location areas (LA) which are used for locating the user for CS traffic; each is served by a VLR, and a VLRmay 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.3GNetworkArchitecture:UMTS 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 fora mobile station to its current SGSN. 42. PDP Context Packet Data Protocol (PDP) context, Encapsulates the association informationbetween the PS core network and the MSfor an active packet session contains the information necessary toperform the SGSN functions. Includes information concerning the type of packet data protocol used associated addresses addresses of upstream GGSNs identifiers to lower layer dataconvergence protocols in the form ofaccess point identifiers, NSAPI and SAPI, to route the packets toand from the access network. The GPRS Tunneling Protocol (GTP) isused for carrying traffic between theSGSN and the GGSN carries control-plane information anduser-plane data. Packet Data Protocol (PDP) context, Encapsulates the association informationbetween the PS core network and the MSfor an active packet session contains the information necessary toperform the SGSN functions. Includes information concerning the type of packet data protocol used associated addresses addresses of upstream GGSNs identifiers to lower layer dataconvergence protocols in the form ofaccess point identifiers, NSAPI and SAPI, to route the packets toand from the access network. The GPRS Tunneling Protocol (GTP) isused for carrying traffic between theSGSN and the GGSN carries control-plane information anduser-plane data.3GNetworkArchitecture:UMTS 43. 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, andretransmissions, 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, andretransmissions, 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 LimitationsTransport protocol stack for UMTS network deployment using ATM backboneLarge complexity of the transport protocol stack for packet data in the PS domain in a typicalUMTS network that uses an ATM backbone to interconnect access and core network entities. 44. UMTS network architecture separation into three domains: CS, PS,and IMS, corresponding roughly to voice, data, and packet-basedmultimedia services. relatively easy migration path from 2G to 3G, preserving infrastructureinvestments 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 toprovide the same functionality (e.g., mobility management) for user traffic withdifferent 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 exchangedbetween different network entities next-generation network should eliminate extraneous interactions, whilemaintaining security and QoS properties. UMTS network architecture separation into three domains: CS, PS,and IMS, corresponding roughly to voice, data, and packet-basedmultimedia services. relatively easy migration path from 2G to 3G, preserving infrastructureinvestments 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 toprovide the same functionality (e.g., mobility management) for user traffic withdifferent 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 exchangedbetween different network entities next-generation network should eliminate extraneous interactions, whilemaintaining security and QoS properties.UMTS Network Architecture Limitations 45. 3G: Mobile Network CDMA2000Complex architecture at the core3GNetworkArchitecture:CDMA2000 46. CDMA2000 Network Architecture3GNetworkArchitecture:CDMA2000Standard CDMA2000 architecture diagram partitioned into different domainsTraditional PSTN andcellular servicearchitecture consisting ofService Control Proxies(SCPs), IntelligentPeripherals, and ServiceNodes 47. 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. Similarlyto 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 SCPor 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. Similarlyto 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 SCPor 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 componentsCS Domain Services in theCDMA2000 architectureWIN components with stand-alone HLRSTP3GNetworkArchitecture:CDMA2000 48. Network Architecture: CDMA2000vs 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) forservice 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) forservice creation, and service platform for open services As for for UMTS, the CS domain is identical to the 2G circuit-switched cellular architecture3GNetworkArchitecture:CDMA2000 However, from an architectural perspective, the UMTS and CDMA2000 systemsdiffer 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 packetsbetween 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 linkcontrol layer for all the packet data acts as the foreign agent or access router, depending on the network configuration and whether thenetwork uses IPv4 or IPv6 to support IP-based mobility with Mobile IP (to be studied in more detailedlater 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 systemsdiffer 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 packetsbetween 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 linkcontrol layer for all the packet data acts as the foreign agent or access router, depending on the network configuration and whether thenetwork uses IPv4 or IPv6 to support IP-based mobility with Mobile IP (to be studied in more detailedlater 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 49. MWIF In comparison with the 3GPP R5 architecture, the MWIF design does notconsider 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 ofATM as in 3GPP R4. The MWIF architecture is based entirely on Voice over IP on the corenetwork (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 notconsider 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 ofATM as in 3GPP R4. The MWIF architecture is based entirely on Voice over IP on the corenetwork (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 50. MWIF Network ArchitectureMWIF layered functional architecture (OMA)3GNetworkArchitecture:MWIFTwo cross-layer functional (vertical) areas Operations, administration, management,and provisioning SecurityFour horizontal layers Applications: third-party applicationsavailable through the mobileoperators network Services: applications within theoperators network, networking support servicessuch as naming and directoryservices Control: mobility management, authorization, accounting, real-time media management, network resourcemanagement, address allocation Transport: Basic IP routing, gateway services to accessnetworksFour horizontal layers Applications: third-party applicationsavailable through the mobileoperators network Services: applications within theoperators network, networking support servicessuch as naming and directoryservices Control: mobility management, authorization, accounting, real-time media management, network resourcemanagement, address allocation Transport: Basic IP routing, gateway services to accessnetworks 51. Network Reference Architecture Developed from the layered functionalarchitecture assigns functional entities to networkentities Design of core network - 68 specificnetwork reference points act as interfaces between the networkentities and outside networks. OpenRAN functional architecture for a radioaccess network based on open, IP-based protocols IP-based signaling and transport forRANs (instead of ATM and SS7 usedin 3G RAN) separation of the control and dataplanes architecture consists of 14 functionalentities separated by 27 referencepoints. Baseline radio protocol is CDMA voice over IP over the air not provided, voice over IP terminates at a functionalentity that adapts the IP traffic to theradio (Similarly to 3G networks)3GNetworkArchitecture:MWIF 52. CDMA2000 & MWIF NetworkArchitecture 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 withthe mobile station this forms a link control layer, there is only one logical link controlconnection 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 formobility management. Edge-based technique for handoff in PS domain, by stretching the PPP tunnel between the old and the new Packet ControlFunction (stretchy PPP) effectively defers the signaling and end-to-end path update between theMS and its correspondent nodes, handling mobility locally. fairly effective in reducing packet loss during the handover. Protocol model for IP packet dataNormal operation while the MS is stationaryMWIF 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 systemsMWIF 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 53. UMTS Service ArchitectureUMTS service classification - a layered structureUMTSServiceArchitecture 3GPP standardizes servicecapabilities (not services), whichconsist of generic bearersdefined by Quality of Service (QoS)parameters such as bandwidth,delay, and symmetryand the mechanisms needed torealize services, including the functionality provided by variousnetwork elements, the communication between them, and the storage of associated data. 3GPP standardizes servicecapabilities (not services), whichconsist of generic bearersdefined by Quality of Service (QoS)parameters such as bandwidth,delay, and symmetryand the mechanisms needed torealize services, including the functionality provided by variousnetwork elements, the communication between them, and the storage of associated data. IP multimedia services deals directly with multimedia(eg. image and videodownload and streaming). Circuit bearer services (at the lowest level) such as circuit-switched transport Circuit teleservices(CS domain) consist of simpletelephone calls, fax Supplementary services(operate on the CS domain) provide enhancements suchas call waiting, call forwarding,and three-way calling. Additional bearer services that can be used bythe 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 notdirectly 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-mailaccess, web browsing, and file transfer. 54. 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)UMTSServiceArchitecture and a collection of service toolkits Specifications of protocols, environments, or APIs for developing services of varioustypes. 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 varioustypes. 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 55. 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 theswitching function fires.UMTSServiceArchitectureSS7 protocol suiteCAMEL is used to provide network intelligence in the UMTSCAMEL 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 mobilityservice functions, such as the MSC or VLR (VisitedLocation Register), and control function, such as the HLR. Used to access as well other functions: Equipment IdentityRegister, Authentication Centre, Short message servicecenter and Serving GPRS Support NodeExamples of CAMEL Services Wireless prepaid service Subscriber establishes an account with the service provider and pays before use in orderto 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 abroadExamples of CAMEL Services Wireless prepaid service Subscriber establishes an account with the service provider and pays before use in orderto 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 56. Service Provisioning: ThreeInteracting Logical Networks Interrogating Network needs the mobile users locationinformation from the HLR in order todeliver a call. The Home Network, unless thenetwork supports optimal routing Contains two logical entities: GMSC gsmSSF: allows GMSC tocommunicate with the gsmSCFThe gsmSRF corresponds to the IN Intelligent Peripheral, andcan play announcements, collect user digits. Visited Network, where the user is currentlylocated, 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, whichcontains 2 logical entities, as in 2Gcellular networks: The HLR stores the CAMEL SubscriptionInformation (CSI) - the subscriberslocation and service profile information, GSM Service Control Function(gsmSCF) The execution environment forservices analogous to the servicecontrol proxy (SCP) in fixed IN net Stores the service logic.service control function (SCF)Mobile Switching Center (MSC)Gateway Mobile Switching Center (GMSC) 57. MExEUMTSServiceArchitectureMExE ServiceEnvironment (MSE)MExEclientMExEclientMExE is the execution environment in the mobile terminal equipmentIn the fixednetwork proxyserversMExE 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 beforeservice commences.MExEdevices may enter in content negotiationwith 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 negotiationwith the MSE to determine requested /available form of content using Hypertext Transport Protocol (HTTP) or the Wireless Session Protocol (WSP)deliver services to the userInforms of MSE capabilities on useMExE devicescan interact toprovide a service.Informs about MExE resources,mechanisms, and supportusing Composite Capability/Preference Profiles (CC/PP)translate content to enable itsdelivery on themobile terminal 58. MExEUMTSServiceArchitectureClassmarksCategories 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 andMobile Information Device Profile (MIDP) environments Classmark 4 based on the Common Language Infrastructure (CLI) CompactProfileClassmarksCategories 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 andMobile Information Device Profile (MIDP) environments Classmark 4 based on the Common Language Infrastructure (CLI) CompactProfileAPIs for Classmark 2PersonalJava supportsweb contentaccess andJava appletsJavaPhone APIallows telephony control,messaging, and personalinformation managementfunctions, such as addressbook and calendar. 59. 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 tointeract with the ME, the user, and USAT servers in the fixednetwork.Among the mechanisms provided are: Profile download Proactive UICC Data download Call control Universal Integrated Circuit Card (UICC) - defined in 3GPPas a physically secure device, like an IC card (or smartcard) that can be inserted into terminals.To access mobile services , it contains SIM/USIM for 2G/3GUMTSServiceArchitecture 60. OSAOSA - 3GPP adopted the Parlay service framework for 3GUMTSServiceArchitectureApplication ServersOpen 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 ServiceCapability Features (SCFs), accessed via a language-independent API. SCFs are encapsulated as Service Capability Servers (SCS). SCS registers itselfwith the frameworkto enable discoveryby applications Applications issue OSAAPI commands to SCS,including commands toperform servicefunctionsregister to be notified ofunderlying networkevents, such as callorigination.Framework: Applications must utilizethe framework to beauthenticated anddiscover the availableSCFs before they accessto the SCFs.OSA APIs used by several vendors and carriers 61. UMTS Service ArchitectureLimitations Providing portable services across networks and terminals, and a common look and feel to theuser interface likely to ease and speed the adoption of services, particularly new services (very attractive), but harddeployment VHE concept faults to ease and speed the development and deployment of large numbers of innovativenew services. vital from the point of view of users, service providers and network operators. Deploying new services rapidly and efficiently requires more flexible and programmablenetworks 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 traditionalnotion of programmability in the PSTN, which assumes that terminals have little or nointelligence, and even from the programmability offered by SAT in GSM. Providing portable services across networks and terminals, and a common look and feel to theuser interface likely to ease and speed the adoption of services, particularly new services (very attractive), but harddeployment VHE concept faults to ease and speed the development and deployment of large numbers of innovativenew services. vital from the point of view of users, service providers and network operators. Deploying new services rapidly and efficiently requires more flexible and programmablenetworks 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 traditionalnotion of programmability in the PSTN, which assumes that terminals have little or nointelligence, and even from the programmability offered by SAT in GSM.VHE concept 62. UMTS Service ArchitectureLimitations (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 ofaccess 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 coherentprogrammability 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 foradvanced 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 JAINAPIs). 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 servicepoint of view. seems a complex application that requires coordinated features from multiple domains and will be moredifficult 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 ofaccess 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 coherentprogrammability 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 foradvanced 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 JAINAPIs). 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 servicepoint of view. seems a complex application that requires coordinated features from multiple domains and will be moredifficult to develop in a coherent manner. 63. CDMA2000 & MWIFService ArchitecturesMWIF Service Architecture Service architecture not explicitly defined Implicitly assumed telephony-oriented services can be developed withan 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 baseprotocolMWIF Service Architecture Service architecture not explicitly defined Implicitly assumed telephony-oriented services can be developed withan 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 baseprotocol3GServiceArchitectures:MWIF&CDMA2000CDMA2000 Service Architecture Similar to that of UMTS same underlying domains (CS and PS) and adopts the IMS for multimediaservices 3GPP2 also adopts the principles of the VHE, although in a slightly differentform. Key differences between the UMTS and CDMA2000 at the networkarchitecture, 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 multimediaservices 3GPP2 also adopts the principles of the VHE, although in a slightly differentform. Key differences between the UMTS and CDMA2000 at the networkarchitecture, particularly in the air interface and RAN design. 64. Limitations of 3G ArchitecturesOverview UMTS network architecture duplicates functionality fordifferent traffic types, has a complex protocol stack, uses a modified SIP protocol thatis relatively heavy weight. UMTS and CDMA2000 servicearchitectures lack a coherent programmabilitysolution Need better logical separation ofnetworking functions andprotocols at the level of thenetwork architecture On the service architecture,provision for developing anddeploying new servicesOverview UMTS network architecture duplicates functionality fordifferent traffic types, has a complex protocol stack, uses a modified SIP protocol thatis relatively heavy weight. UMTS and CDMA2000 servicearchitectures lack a coherent programmabilitysolution Need better logical separation ofnetworking functions andprotocols at the level of thenetwork architecture On the service architecture,provision for developing anddeploying new servicesArchitecture Limitations 65. Motivations for an all-IP network Enable large variety of innovative and commercially lucrative services Simpler protocol stackMotivations for an all-IP network Enable large variety of innovative and commercially lucrative services Simpler protocol stackNext Generation ArchitecturesThe All-IP ModelPSTN 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 personnelin closed environments, using specializedlanguages and tools.IP networks low entry barriers into the market open and rapid proliferation of knowledge Large number of creative programmers andentrepreneurs available, possibility of developing advanced servicesat the edge of the networkGreater availability ofpersonnel, tools, andsupport for applicationdevelopment for IPnetworks than for thePSTN.IP technical simplicity IP acts as a unifying abstraction lesscomplex protocol stack Hides heterogeneity of protocols andnetworks below it Easier application development for IPnetworksRapid development anddeployment of a largenumber of Internetapplications, competingwith the PSTNs currentor 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), 66. All-IP Network - Barriers Development of open standard APIs (eg. JAIN, Parlay) APIs provide programming abstractions that operate acrossPSTN, ATM, and IP networks. underlying transport network less important JAIN APIs have been developed for individual protocol applications get improved performance / fine-grained control canin exchange for increased programming complexity JAIN APIs not only for IPs, such as SIP, but also for SS7protocols, such as ISUP and TCAP. IP protocols - Number, Complexity, and Size grows rapidly, reaching traditional PSTN protocols. Standardization delay increasingly longer (approaching traditional PSTN protocolsdelays) Development of open standard APIs (eg. JAIN, Parlay) APIs provide programming abstractions that operate acrossPSTN, ATM, and IP networks. underlying transport network less important JAIN APIs have been developed for individual protocol applications get improved performance / fine-grained control canin exchange for increased programming complexity JAIN APIs not only for IPs, such as SIP, but also for SS7protocols, such as ISUP and TCAP. IP protocols - Number, Complexity, and Size grows rapidly, reaching traditional PSTN protocols. Standardization delay increasingly longer (approaching traditional PSTN protocolsdelays)Rise of Internet applications Needed efficient integration of telecommunications network with the Internet for access to / interact with internet applications via the network 67. 3.5GMiddleware API offers applications, with the required securityand billing credentials, access to higher-layerfunctions, such as: access to overlay network elements for contentdistribution or multicast, location and other context information servers, security certificate authorities.Middleware API offers applications, with the required securityand billing credentials, access to higher-layerfunctions, such as: access to overlay network elements for contentdistribution or multicast, location and other context information servers, security certificate authorities.The Second Waist andProgrammability Independent software vendors andsystem integrators to develop newapplications and solutions (similarly to PCindustry) Next generation networks defined byavailability of innovative applications Programmable IP-based nextgeneration network Powerful and well-defined APIs forrapid application development. Second waist at the interface betweenapplications and the middleware. It must hide the heterogeneity of theprotocol stack and software layersbetween the application and the IPwaist. offer a high level of abstraction andflexibility than the core network API Web services, including WSDL,SOAP, and UDDI securilly protect overall network allow billing for network use Independent software vendors andsystem integrators to develop newapplications and solutions (similarly to PCindustry) Next generation networks defined byavailability of innovative applications Programmable IP-based nextgeneration network Powerful and well-defined APIs forrapid application development. Second waist at the interface betweenapplications and the middleware. It must hide the heterogeneity of theprotocol stack and software layersbetween the application and the IPwaist. offer a high level of abstraction andflexibility than the core network API Web services, including WSDL,SOAP, and UDDI securilly protect overall network allow billing for network useLayered APIsthird-partyapplicationsdominating interms of trafficand revenuesCore network API provides interfaces for internet signalingand coordination protocols from the network, transport, and sessionlayers (i.e.,layers 35) of the OSI Referencemodel (such as SIP, Mobile IP). allows applications with security and billingauthority to obtain fine-grained control overcore network resources and functions.Core network API provides interfaces for internet signalingand coordination protocols from the network, transport, and sessionlayers (i.e.,layers 35) of the OSI Referencemodel (such as SIP, Mobile IP). allows applications with security and billingauthority to obtain fine-grained control overcore network resources and functions. 68. Conclusions 3G architectures significant limitations both at the level of network and servicearchitectures. all-IP architecture is the best candidate for developing innovativeand 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 servicesFor Next Generation networks, the key features anddifferentiators will lie at the service architecture levels.For Next Generation networks, the key features anddifferentiators will lie at the service architecture levels.