Transcript T1_tecnologias

Tema 1:
Tecnologías de red.
Estructura
de Internet
Redes “core”


SONET
DWDM
Redes



de acceso
Redes cableadas: Ethernet et al.
Redes inalámbricas: IEEE 802.11 et al.
Otras tecnologías
Transmisión de Datos Multimedia - Master IC 2006/2007
What’s the Internet: “nuts and bolts” view
Transmisión de Datos Multimedia - Master IC 2006/2007

End systems
Host computer
 Network applications


Access networks
Local area networks
 communication links


Network core:
router
server
workstation
mobile
local ISP
routers
 network of networks

regional ISP
Computer Networking: A Top Down Approach
Featuring the Internet,
3rd edition.
Jim Kurose, Keith Ross
Addison-Wesley, July 2004.
company
network
2
What’s the Internet: “nuts and bolts” view
Transmisión de Datos Multimedia - Master IC 2006/2007

Protocols control sending, receiving
of msgs


e.g., TCP, IP, HTTP, FTP, PPP
Internet: “network of networks”
loosely hierarchical
 public Internet versus private
intranet


router
server
workstation
mobile
local ISP
Internet standards
RFC: Request for comments
 IETF: Internet Engineering Task
Force

regional ISP
company
network
3
Network Components (Examples)
Transmisión de Datos Multimedia - Master IC 2006/2007
Links
Interfaces
Fibers
Ethernet card
Switches/routers
Large router
Wireless card
Coaxial Cable
Switch
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Juniper Routers
5
Internet structure: network of networks
roughly hierarchical
 at center: “tier-1” ISPs (e.g., MCI, Sprint, AT&T, Cable and
Wireless), national/international coverage
Transmisión de Datos Multimedia - Master IC 2006/2007


treat each other as equals
Tier-1
providers
interconnect
(peer)
privately
Tier 1 ISP
Tier 1 ISP
NAP
Tier-1 providers
also interconnect
at public network
access points
(NAPs)
Tier 1 ISP
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Transmisión de Datos Multimedia - Master IC 2006/2007
Tier-1 ISP: e.g., Sprint
Sprint US backbone network
DS3 (45 Mbps)
OC3 (155 Mbps)
OC12 (622 Mbps)
OC48 (2.4 Gbps)
Seattle
Tacoma
Stockton
San Jose
Cheyenne
Kansas City
New York
Pennsauken
Relay
Wash. DC
Chicago
Roachdale
Anaheim
Atlanta
Fort Worth
Orlando
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Internet structure: network of networks
Transmisión de Datos Multimedia - Master IC 2006/2007

“Tier-2” ISPs: smaller (often regional) ISPs

Connect to one or more tier-1 ISPs, possibly other tier-2 ISPs
Tier-2 ISP pays
tier-1 ISP for
connectivity to
rest of Internet
 tier-2 ISP is
customer of
tier-1 provider
Tier-2 ISP
Tier-2 ISP
Tier 1 ISP
Tier 1 ISP
Tier-2 ISP
NAP
Tier 1 ISP
Tier-2 ISPs
also peer
privately with
each other,
interconnect
at NAP
Tier-2 ISP
Tier-2 ISP
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Internet structure: network of networks
Transmisión de Datos Multimedia - Master IC 2006/2007

“Tier-3” ISPs and local ISPs

last hop (“access”) network (closest to end systems)
local
ISP
Local and tier3 ISPs are
customers of
higher tier
ISPs
connecting
them to rest
of Internet
Tier 3
ISP
Tier-2 ISP
local
ISP
local
ISP
local
ISP
Tier-2 ISP
Tier 1 ISP
Tier 1 ISP
Tier-2 ISP
local
local
ISP
ISP
NAP
Tier 1 ISP
Tier-2 ISP
local
ISP
Tier-2 ISP
local
ISP
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Internet structure: network of networks
Transmisión de Datos Multimedia - Master IC 2006/2007

a packet passes through many networks!
local
ISP
Tier 3
ISP
Tier-2 ISP
local
ISP
local
ISP
local
ISP
Tier-2 ISP
Tier 1 ISP
Tier 1 ISP
Tier-2 ISP
local
local
ISP
ISP
NAP
Tier 1 ISP
Tier-2 ISP
local
ISP
Tier-2 ISP
local
ISP
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Transmisión de Datos Multimedia - Master IC 2006/2007
Network Access Points (NAPs)
Note: Peers in this context are
commercial backbones..droh
Source: Boardwatch.com
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Transmisión de Datos Multimedia - Master IC 2006/2007
MCI/WorldCom/UUNET Global Backbone
Source: www.lightreading.com
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Transmisión de Datos Multimedia - Master IC 2006/2007
The situation in Europe
See: http://www.geant2.net/server/show/nav.1368
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Tema 1:
Tecnologías de red.
Estructura
de Internet
Redes “core”


SONET
DWDM
Redes



de acceso
Redes cableadas: Ethernet et al.
Redes inalámbricas: IEEE 802.11 et al.
Otras tecnologías
Transmisión de Datos Multimedia - Master IC 2006/2007
Transmisión de Datos Multimedia - Master IC 2006/2007
IP and Traditional Transport

In the 80’s, software based routers were interconnected via
relatively slow links




56K (early 80’s),
to fractional T1, to full T1,
to T3
This was layered over core TDM infrastructure

Which was intended for voice and circuits
Generally, data folks ignored TDM folks,
and vice versa
 [On the edge, there has always been a wide range of links
(Ethernet, ...)]

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Transmisión de Datos Multimedia - Master IC 2006/2007
Traditional View of Routers and Links
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Reality has always been more complex
Terminal
Multiplexer
Terminal
Multiplexer
SONET/SDH
ADM
SONET/SDH
ADM
SONET/SDH
DCS
SONET/SDH
DCS
SONET/SDH
ADM
SONET/SDH
DCS
Terminal
Multiplexer
SONET/SDH
ADM
Terminal
Multiplexer
SONET/SDH
ADM
Terminal
Multiplexer
SONET/SDH
ADM
Terminal
Multiplexer
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Transmisión de Datos Multimedia - Master IC 2006/2007
Time Division Multiplexing
Source 1
Source 2
Source 3
MUX
Sync
Bit
Time
Slot1
Time
Slot2
Time
Slot3
Time
Slot4
TimeS
lot5
TimeS
lot6
SyncB
it
Time
Slot1
Time
Slot2
Source 4
Source 5
Source 6
Multiplexed Bit Stream
Sum of sources = Total MUX’d bit stream
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Transmisión de Datos Multimedia - Master IC 2006/2007
Digital Hierarchy
North America
Bit Rate (Mbps)
Name
Bit Rate (Mbps)
Container
International
Transport
Name
Bit Rate (Mbps)
Container
Transport
40000
STS/OC-768
STM-256
10000
STS/OC-192
STM-64
2500
STS/OC-48
STM-16
STS/OC-12
STM-4
STS/OC-3
STM-1
622
155
140
E4
51
45
DS-3/T3
1.5
DS-2/T2
DS-1/T1
STS-1 SPE
45
8
2
VC4
STS/OC-1
34
6
140
E3
34
E2
8
E1
2
E0
0.064
VC3
6
VC12
1.5
0.064
VT1.5
0.064
STS-1: Payload 49.536 Mbps + Overhead 2.304 Mbps
(4.5 %)
Total = 51.84 Mbps
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Transmisión de Datos Multimedia - Master IC 2006/2007
SONET Hierarchy
OC-N
NxSTS-1
DS-O
VT1.5=1 DS-1
+ OVERHEAD
STS-1=28 VT1.5s/1 DS-3
+ OVERHEAD
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Transmisión de Datos Multimedia - Master IC 2006/2007
SONET/SDH Framing
Payload Options
STS-1 Frame Format
90 Columns
SECT
OVHD
One
DS-3
P
A
T
H
PAYLOAD
LINE
OVHD
O
V
H
D
DS-1
Or
Virtual
Tributary
(VT1.5)
(1.7Mb/s)
Transport STS-1 Synchronous Payload Envelope
Overhead 3
87 Columns
columns
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SONET/SDH Features
Transmisión de Datos Multimedia - Master IC 2006/2007

Rapid and predictable restoration
10s of ms; depends on ring size
 Simple to engineer

Standard framing and multiplexing
(Time Division Multiplexing [TDM])
 Maintainability

Performance monitoring
 Fault isolation and sectioning
 Bandwidth management
 Network management


Consolidation


Reduction in wasted capacity
Challenge

Remove complexity
and keep benefits
Traffic
Quickly
Rerouted
After Failure
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SONET/SDH Benefits
Transmisión de Datos Multimedia - Master IC 2006/2007







Standard framing, rates, procedures,
and interfaces
High transmission rates
Survivability
Separation of circuits
Integrated network management
Multi-vendor compatibility
End-to-end provisioning and maintenance
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SONET/SDH Limitations
Transmisión de Datos Multimedia - Master IC 2006/2007

Difficult to scale



Space, power, one wavelength per chassis
Slow and costly to provision

Planning complexity

Delivery measured in weeks
Limited service offerings


Static not dynamic bandwidth
Granularity – why not 5.5Gbps ?
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Transmisión de Datos Multimedia - Master IC 2006/2007
Optical Fiber Evolution

Fiber is better than copper wire


Purity – low attenuation and distortion
Multimode
 Longer distances, fiber
lower bit error rates
Higher
frequency
signals
– massive
bandwidth
 Low
cost
–
LEDs,
not
lasers

Single-mode fiber
 Different wavelengths – massive bandwidth
 Many wavelengths (modes)
 Onetowavelength
– small
core fiber
 Immunity
noisedispersion

Non-zero
shifted
 Dispersion
bandwidth
and distance
 Security
– difficult
to –
taplimitsand
 Less
interference
loss
 Optimized
forspread
longer
 Light
pulses
outdistances
 Small size
and
weight
 Greater distance (up to 100 km)

Easier
installation for

Intramodal
– different
delay per mode
 Optimized
higher bandwidth

More
components
 Bundles
ofexpensive
fibers in2same
space
as copper
wire – lasers

Typically
km
maximum
distance
 Minimized dispersion point shifted to 1550 nm
 Minimized dispersion point at 1310 nm
 Large
diameter
cores – for
multiple
modes
 Suitable
for Erbium-based
optical
amplifiers

 Not suitable for EDFA (Erbium Doped Fiber-optic
 Silica-based
Initially flat profile
fibers have lowest attenuation at 1550
Amplifier)
not
1310end improves performance
 Stepped
nm,
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SONET/SDH ADM
Single Fiber
SONET/SDH ADM
SONET/SDH ADM
From One Wavelength Per
Fiber to Many
ADM
ADM
WDM Node
WDM Node
ADM
OT
ADM
OT
Transmisión de Datos Multimedia - Master IC 2006/2007
Wave Division Multiplexing
ADM
ADM
Single Fiber
ADM
ADM
OT = Optical Transponder
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Transmisión de Datos Multimedia - Master IC 2006/2007
WDM System Elements
SONET/SDH
ADM
SONET/SDH
ADM
SONET/SDH
ADM
SONET/SDH
ADM
SONET/SDH
ADM
= Regenerators
SONET/SDH
ADM
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Laser
Output
l1
l1 … ln
OT
Transmisión de Datos Multimedia - Master IC 2006/2007
TDM and WDM Relationship
ln
TDM generates output from
sum of inputs into a single
bit stream
WDM changes TDM bit stream into
wavelengths between 1532 nm and
1560 nm
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Dense and Ultra Dense WDM
l1
WDM 8 Lambdas
l2
l1
l2
2.5 Gbps per lambda
l8
l8
EDFA = Erbium Doped Fiber-optic Amplifier
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Transmisión de Datos Multimedia - Master IC 2006/2007
Dense and Ultra Dense WDM
l1
l1
l2
l2
DWDM 40 Lambdas
l39
10 Gbps per lambda
l40
l39
l40
EDFA = Erbium Doped Fiber-optic Amplifier
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Transmisión de Datos Multimedia - Master IC 2006/2007
Dense and Ultra Dense WDM
l1
l1
l2
l2
l3
UDWDM 192 Lambdas
40 Gbps per lambda
l3
l190
l190
l191
l191
l192
EDFA = Erbium Doped Fiber-optic Amplifier
l192
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Tema 1:
Tecnologías de red.
Estructura
de Internet
Redes “core”


SONET
DWDM
Redes



de acceso
Redes cableadas: Ethernet et al.
Redes inalámbricas: IEEE 802.11 et al.
Otras tecnologías
Transmisión de Datos Multimedia - Master IC 2006/2007
La famila Ethernet (IEEE 802.3)
Transmisión de Datos Multimedia - Master IC 2006/2007

IEEE 802.3 (1985)  “Ethernet”





Ethernet implementa un protocolo MAC del tipo 1-persistente CSMA/CD.
Soporta diferentes medios de transmisión con anchos de banda entre 1 y
10Mbps.
Puede trabajar en banda base y en banda ancha, utilizando técnicas de
codificación y modulación.
Se considera un red con topología de tipo bus.
IEEE 802.3u (1995)  “FastEthernet (FE)”

Ethernet de alta velocidad (100 Mbps).
 Incremento del ancho de banda (un orden de magnitud).

Compatibilidad con las redes Ethernet 10Mbps
 Instalación rápida, reutilización de recursos.
 Las modificaciones se centran en el nivel físico.

El cableado es muy similar.
 Se necesitan codificaciones especiales para conseguir 100Mbps.

No es necesario adaptar el software de red:
 Utiliza el mismo MAC.
 El formato de la trama es idéntico al especificado en IEEE 802.3.
33
La famila Ethernet (IEEE 802.3)
Transmisión de Datos Multimedia - Master IC 2006/2007

IEEE 802.3z (1998)  “Gigabit Ethernet (GE)”




Ethernet de muy alta velocidad (1Gpbs).
Se dispone de productos GE (switches, hubs, etc.)
Inicialmente no se considera un cableado UTP
CSMA/CD (Half-duplex):
 Tiene problemas de tamaños de trama, colisiones, etc.



Solución para troncales de alta capacidad.
¿ ATM o Gigabit Ethernet ?
Comercialmente se impondrá GE FDX.
 Sistemas basados en conmutadores que actuarán como troncales en redes
corporativas

IEEE 802.3ae (2002)  “10 Gigabit Ethernet (10GE)”


Multiplica por 10 el ancho de banda de GE.
Cableado:
 Sólo fibra óptica.

Sólo funciona en modo full-duplex
 Desaparece el modo CSMA/CD (Half-duplex).

Soporte para...
 LANs
 MANs
 WANs.
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La familia Ethernet (IEEE 802.3)
Transmisión de Datos Multimedia - Master IC 2006/2007
 Evolución
de Ethernet y otras tecnologías…
Ethernet (10 Mb)
Fast Ethernet
Gigabit Ethernet
10 Gigabit Ethernet
vs.
vs.
vs.
vs.
Token Ring
FDDI
ATM
???
35
¿Ethernet para el transporte de datos multimedia?
Transmisión de Datos Multimedia - Master IC 2006/2007

 Reparto no equilibrado de recursos.

En condiciones de alta ocupación no se reparte el ancho de banda
de forma equitativa.
 El ancho de banda que una estación obtiene de la red es proporcional
al tamaño medio de sus tramas.
– Aplicaciones como FTP, HTTP, flujos de vídeo obtienen más ancho
de banda que otras como TELNET o voz IP.

Soluciones:
 Diseño de red adecuado.
 Sobredimensionar la capacidad de la red.

Transmisión full-duplex (1997).
Una estación puede enviar y recibir tramas al mismo tiempo 
NO SE REQUIERE CSMA/CD.
 Ventajas

 Canal dedicado  Incremento de prestaciones.
 Elimina la restricción de la distancia máxima.
 Simplifica el funcionamiento del hardware.
 Elimina los problemas de reparto no equilibrado de recursos.
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¿Ethernet para el transporte de datos multimedia?
Transmisión de Datos Multimedia - Master IC 2006/2007

Tráfico con prioridades (IEEE 802.1p/Q) - 1998.
Define los mecanismos necesarios para priorizar el tráfico
en redes Ethernet.
 Permite asignar a cada trama un nivel de prioridad de 0
(más baja) a 7 (más alta).

Utiliza una extensión de la cabecera de trama Ethernet, que
se conoce como VLAN tag (etiqueta) que contiene:
– Identificador de VLAN (8 bits).
– Un campo de prioridad (3 bits).

Los conmutadores, así como los hosts, procesan las
tramas entrantes de acuerdo a su prioridad.
No se envían las tramas de un nivel de prioridad si todavía
hay tarmas pendientes de envío de mayor prioridad.

No define mecanismos de control de admisión.
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Bandwidth: Gb and 10Gb Ethernet
Transmisión de Datos Multimedia - Master IC 2006/2007
Alternative solution
File Servers
SMC8708 layer 8 port 10GB switch
Stack of 2x
SMC8748M
10 Gbps Uplinks
PC users
1 Gbps
………
1 Gbps
………
Power
users
10 Gigabit Ethernet implementation.
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Transmisión de Datos Multimedia - Master IC 2006/2007
Scenario: VOiP Support
File
server
Guest
server
Employee VLAN
SMC2555W-AG
Username:
Password:
VLAN tagging
PoE
SMC6824MPE
Username:
Password:
PoE
SMC8624T
VoIP phones
VLAN tagging
Internet
Guest VLAN
SMC2555W-AG
VLAN tagging
PoE
RADIUS
server
SMC6824MPE
PoE
VoIP phones
VoIP support
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Transmisión de Datos Multimedia - Master IC 2006/2007
Scenario: Enterprise
SMC6824MPE Stack
SMC8748ML3
PoE
STP
Server with
10G uplink
Power-User
54 Mbps WLAN + Video Surveillance
SMC8748M Stack
VRRP
LACP
Gigabit
Trunks
Server with
10G Uplink
STP
SMC8724ML3
Stack
SMC6248M Stack
Subnet 1
IP Phone Call-Center
Internet
Subnet 2
PoE
Router
SMC6824MPE
40
Transmisión de Datos Multimedia - Master IC 2006/2007
10 Gigabit ETHERNET
41
Otras tecnologías LAN
Transmisión de Datos Multimedia - Master IC 2006/2007
 No
son tecnologías de LAN populares
 Son alternativas que intentan explotar aspectos de:

Reserva de ancho de banda, tráfico con prioridades, altas
prestaciones (anchos de banda, latencias, etc).
 100VGAnyLan

Soporta tráfico con prioridades.
 HIPPI

(IEEE 802.12 - 1995).
y Fibre Channel.
Definen enlaces de datos de muy alta capacidad y bajo
retardo.
 Myrinet.

Tecnología heredada de los multicomputadores 
Retardos muy pequeños y acotados.
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WLANs, El estándar IEEE 802.11
Transmisión de Datos Multimedia - Master IC 2006/2007

En el 1997 nace el:

IEEE Working Group for WLAN Standards:
http://grouper.ieee.org/groups/802/11/index.html

Se define el MAC y tres diferentes niveles físicos, que operan a
1Mbps y 2Mbps:




IEEE Std 802.11a (diciembre 1999):



Infrarrojos (IR) en banda base
Frequency hopping spread spectrum (FHSS), banda de 2,4 GHz
Direct sequence spread spectrum (DSSS), banda de 2,4 GHz
Otro estándar de nivel físico: Orthogonal frequency domain multiplexing
(OFDM)
Network
Network
Hasta 54 Mbps
L
IEEE Std 802.11b (enero 2000):

Extensión de DSSS; hasta 11 Mbps
IEEE Std 802.11g (Junio 2003)
 Etc.

Data
Link
IEEE 802.2. LLC
ISO 8802.2
L
C
M
A
C
Data Link
Ethernet
v2.0
Physical
http://standards.ieee.org/getieee802/802.11.html
IEEE
802.3
IEEE
802.11
ISO
8802.3
ISO
8802.11
43
Arquitectura 802.11
Transmisión de Datos Multimedia - Master IC 2006/2007
Estructura
descentralizada
Independent Basic Service Set (IBSS)
Flexible:
Redes pequeñas y grandes,
Redes transitorias y
permanentes
Control
potencia
del consumo de
Componentes:
Estación (STA)
Access
infrastructure Basic Service Set (BSS)
Point (AP)
Basic
Service Set (BSS)
Extended Service Set (ESS)
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Transmisión de Datos Multimedia - Master IC 2006/2007
Servicios

La arquitectura IEEE 802.11 define 9 servicios: para la estación y
para la distribución

Station services:





Authentication
Deauthentication
Privacy  WEP
Data delivery
Parecidos a conectar/desconectar
el cable en una red tradicional
Distribution services:





Association
Disassociation
Reassociation
Distribution
integration
 genera una conexión entre STA y AP
 como association pero informando del AP anterior
 conexión de la WLAN con otras LANs;
uso de un portal
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El MAC: entrega de datos fiable
CSMA/CA con binary
exponential backoff
Servicios sin contienda
El protocolo mínimo consiste
de dos tramas: DATOS+ACK
 El standard propone RTS-CTSDATOS-ACK
MAC

Servicios
con contienda
Point
Coordination
Function (PCF)
Distributed Coordination
Function (DCF)
Los 5 valores de timing:
• Slot time
• SIFS: short interframe space
• PIFS: PCF interframe space (=SIFS+1slot)
• DIFS: DCF interframe space (=SIFS+2slots)
• EIFS: extended interframe space
DIFS
DIFS
ventana de contienda
PIFS
busy medium
SIFS
defer access
slot
Transmisión de Datos Multimedia - Master IC 2006/2007

46
Mecanismo de detección de portadora
Transmisión de Datos Multimedia - Master IC 2006/2007

Se basa en el network allocation vector (NAV)
DIFS
fuente
data
RTS
SIFS
destino
SIFS
SIFS
ACK
CTS
DIFS
otro STA
NAV (RTS)
NAV (CTS)
ventana de contienda
defer access
47
QoS: 802.11e and WMM™
QoS needed for audio, voice, video
 Original Wi-Fi® didn’t have QoS
 IEEE 802.11e is new QoS standard
Transmisión de Datos Multimedia - Master IC 2006/2007




Still in process after more than 4 years
Both “prioritized” and “guaranteed” QoS
WMM (Wi-Fi Multimedia)




Prioritized QoS subset of 802.11e draft
Widely accepted by 802.11e members
Added to Wi-Fi certification in September 2004
Already included in some products
48
Transmisión de Datos Multimedia - Master IC 2006/2007
WMM™ for Video
Source: Wi-Fi Alliance
49
Bluetooth Specifications
Bluetooth is a system solution comprising hardware, software
and interoperability requirements. The Bluetooth specifications
specify the complete system.
 De facto standard - open specifications.
 Two part document - Volume 1:Core and Volume 2:Profiles.
 Bluetooth specs developed by Bluetooth SIG.
Transmisión de Datos Multimedia - Master IC 2006/2007


February 1998: The Bluetooth SIG is formed
 promoter company group: Ericsson, IBM, Intel, Nokia, Toshiba




May 1998: The Bluetooth SIG goes “public”
July 1999: 1.0A spec (>1,500 pages) is published
December 1999: ver. 1.0B is released
December 1999: The promoter group increases to 9
 3Com, Lucent, Microsoft, Motorola

February 2000: There are 1,500+ adopters
0.7 ---> 0.9 ---> 1.0A ---> 1.0B ---> 1.1 -->
 November 2003: release 1.2
 Currently (November 2004), release 2.0


(aka EDR or Extended Data Rate) triples the data rate up to about 2 Mb/s
50
Transmisión de Datos Multimedia - Master IC 2006/2007
release 2.0: the new partitioning
51
Bluetooth usage
Transmisión de Datos Multimedia - Master IC 2006/2007

Low-cost, low-power, short range radio  a cable replacement
technology




Common (File transfer, synchronisation, internet bridge, conference table)
Hidden computing (background synchronisation, audio/video player)
Future (PC login, remote control)
Why not use Wireless LANs?


power
cost
52
Bluetooth RF
1 Mb/s symbol rate
 Normal range
10m (0dBm)
 Optional range
100m (+20dBm)
 Normal transmission power
0dBm (1mW)
 Optional transmission power
-30 to +20dBm (100mW)
 Receiver sensitivity
-70dBm
 Frequency band
2.4Ghz ISM band
 Gross data rate
1Mbit/s
 Max data transfer
721+56kbps/3 voice channels
 Power consumption 30uA(max), 300uA(standby),
~50uA(hold/park)
 Packet switching protocol based on frequency hop scheme with
1600 hops/s
Transmisión de Datos Multimedia - Master IC 2006/2007

53
Transmisión de Datos Multimedia - Master IC 2006/2007
Bluetooth Power Class Table
Power Class
Max Output Power
Max Output Power
Expected Range
Range in
Free Space
Class 1
100mW
20dBm
42m
300m
Class 2
2.5mW
4dBm
16m
50m
Class 3
1mW
0dBm
10m
30m
54
Bluetooth Network Topology
Transmisión de Datos Multimedia - Master IC 2006/2007

Bluetooth devices have the ability to work as a slave or a master
in an ad hoc network. The types of network configurations for
Bluetooth devices can be three.


o
Single point-to-point (Piconet): In this topology the network consists of one
master and one slave device.
Multipoint (Piconet): Such a topology combines one master device and up
to seven slave devices in an ad hoc network.
Scatternet: A Scatternet is a group of Piconets linked via a slave device in
one Piconet which plays master role in other Piconet.
The Bluetooth standard
M
M
M
Master/Slave
S
M
S
S
S
S
S
i) Piconet (Pointto-Point)
S
S
ii) Piconet (Multipoint)
S
S
iii) Scatternet
does not describe any
routing protocol for
scatternets and most of
the hardware available
today has no capability
of forming scatternets.
Some even lack the
ability to communicate
between slaves of one
piconet or to be a
member of two piconets
at the same time.
55
Transmisión de Datos Multimedia - Master IC 2006/2007
Bluetooth stack: short version
Applications
RFCOMM
SDP
L2CAP
HCI
Link Manager
Baseband
RF
56
Transport Protocol Group (contd.)
Transmisión de Datos Multimedia - Master IC 2006/2007

Radio Frequency (RF)


Baseband



Defines the timing, framing
Flow control on the link.
Link Manager




Sending and receiving
modulated bit streams
The Radio, Baseband and Link
Manager are on firmware.
 The higher layers could be in software.
 The interface is then through the Host
Controller (firmware and driver).
 The HCI interfaces defined for
Bluetooth are UART, RS232 and USB.

Managing the connection states.
Enforcing Fairness among
slaves.
Power Management
Logical Link Control & Adaptation
Protocol



Handles multiplexing of higher
level protocols
Segmentation & reassembly of
large packets
Device discovery & QoS
BLUETOOTH SPECIFICATION, Core Version 1.1 page 543
Source: Farinaz Edalat, Ganesh Gopal, Saswat Misra, Deepti Rao
57
Physical Link Definition
Transmisión de Datos Multimedia - Master IC 2006/2007

Synchronous Connection-Oriented (SCO) Link




circuit switching
symmetric, synchronous services
slot reservation at fixed intervals
Asynchronous Connection-Less (ACL) Link




packet switching
(a)symmetric,
asynchronous services
polling access scheme
58
Transmisión de Datos Multimedia - Master IC 2006/2007
ACL data rates
P
a
c
k
e
tt
y
p
e
N
a
m
e
S
y
m
m
e
t
r
ic
(
k
b
p
s
)
A
s
y
m
m
e
t
r
ic
(
k
b
p
s
)
1s
lo
t+
F
E
C
D
M
1
1
0
8
.8
1
0
8
.8
1
0
8
.8
1s
lo
t
D
H
1
1
7
2
.8
1
7
2
.8
1
7
2
.8
3s
lo
t+
F
E
C
D
M
3
2
5
6
.0
3
8
4
.0
5
4
.4
3s
lo
t
D
H
3
3
8
4
.0
5
7
6
.0
8
6
.4
5s
lo
t+
F
E
C
D
M
5
2
8
6
.7
4
7
7
.8
3
6
.3
5s
lo
t
D
H
5
4
3
2
.6
7
2
1
.0
5
7
.6
59
Transmisión de Datos Multimedia - Master IC 2006/2007
Multi-slot packets
fn
fn+1
fn+2
fn+3
fn+4
fn+5
Single slot
Three slot
Five slot
60
Transmisión de Datos Multimedia - Master IC 2006/2007
Symmetric single slot
fn
fn+1
fn+2
fn+3
fn+4
fn+5 fn+6
fn+7
fn+8
fn+9
fn+10 fn+11 fn+12
Master
Slave
61
Transmisión de Datos Multimedia - Master IC 2006/2007
Mixed Link Example
MASTER
SCO
ACL
SCO
ACL
ACL SCO
SCO
ACL
SLAVE 1
SLAVE 2
SLAVE 3
62
Polling on ACL links
Transmisión de Datos Multimedia - Master IC 2006/2007




Slave is allowed to send only after it has been polled.
Master polls slave at least Npoll slots (negotiated).
Master may send at will.
Polling algorithm is proprietary.
POLL
Data
Master
Data
Slave
Slot
time
TDD frame
63
Bluetooth Connection States
Transmisión de Datos Multimedia - Master IC 2006/2007





There are four Connection states on
Bluetooth Radio:
Active: Both master and slave
participate actively on the channel by
transmitting or receiving the packets
(A,B,E,F,H)
Sniff: In this mode slave rather than
listening on every slot for master's
message for that slave, sniffs on
specified time slots for its messages.
Hence the slave can go to sleep in the
free slots thus saving power (C)
Hold: In this mode, a device can
temporarily not support ACL packets
and go to low power sleep mode to
make the channel available for things
like paging, scanning etc (G)
Park: Slave stays synchronized but not
participating in the Piconet, then the
device is given a Parking Member
Address (PMA) and it loses its Active
Member Address (AMA) (D,I)
A
H
B
C
Master
H
D
E
I
G
C
F
Bluetooth Connection States
64
Bluetooth Forming a Piconet
Transmisión de Datos Multimedia - Master IC 2006/2007







Inquiry: Inquiry is used to find the
identity of the Bluetooth devices in the
close range.
Inquiry Scan: In this state, devices are
listening for inquiries from other
devices.
Inquiry Response: The slave responds
with a packet that contains the slave's
device access code, native clock and
some other slave information.
Page: Master sends page messages by
transmitting slave's device access code
(DAC) in different hop channels.
Page Scan: The slave listens at a single
hop frequency (derived from its page
hopping sequence) in this scan
window.
Slave Response: Slave responds to
master's page message
Master Response: Master reaches this
substate after it receives slave's
response to its page message for it.
Master
Inquiry
Slave
1
Inquiry Scan
2
3
Page
Inquiry
Response
4
5
Page Scan
Slave Response
6
Master
Response
7
Connection
Connection
Forming a Piconet Procedures
65
2G, 3G and Beyond
An
Understanding of Technology and Services
Transmisión de Datos Multimedia - Master IC 2006/2007
2G: Technology Summary
Transmisión de Datos Multimedia - Master IC 2006/2007

TDMA: Time Division Multiple Access





GSM: Global System of Mobile communications




Standardized in 1990 as IS-54
Provides 3-6 times capacity increase over AMPS (1G)
Peak data rate of 14.4kpbs (can bundle up to 8 channels)
Introduced authentication and encryption for security
Standardized in 1992, based on TMDA technology
Improved battery life over TDMA
GPRS peak data rates of 140 kbps; EDGE data rates of 180kbps
CDMA: Code Division Multiple Access



Standardized in 1993 as IS-95
Provides 1.5-2 times capacity increase over TDMA
Peak data rate of 14.4kpbs (can bundle up to 8 channels)
67
2G: Winners & Losers
Transmisión de Datos Multimedia - Master IC 2006/2007

TDMA



CDMA



Marginally better capacity than GSM, marginally worse battery life
No evolution path beyond 2G – DEAD END !!
Lots of hype on capacity, delivered on upwards of 2x capacity improvement
over TDMA/GSM
Clear evolution to 3G
GSM



International Roaming and Compatibility
Clear evolution to 3G
Defacto Global Standard
68
GSM: A Success Story
Transmisión de Datos Multimedia - Master IC 2006/2007
Growth in China
GSM subscribers in Asia Pacific reached 650
million in March 2006
(521 million March 2005 = 24.7% annual growth)
China
GSM grew over 54 mil subs in past
12 months = over 1 million/week
Cdma added under 5 mil subs in
the same period
GSM growth exceeded CDMA by 11x from March 05 to March 06
69
GSM: A Success Story
Transmisión de Datos Multimedia - Master IC 2006/2007
Growth in India
India reached almost 64 million
GSM subscribers at 31.03.06
GSM has 77.5% market share
GSM additions = 22.7 million in
12 months = over 55% growth
Cdma added 8 million in same
period
70
GSM: A Success Story
Transmisión de Datos Multimedia - Master IC 2006/2007
Growth in Rest of World
Africa:
146 million (62.6% annual growth)
Americas:
Canada and USA 85 million (35% annual growth)
Latin America and the Caribbean 144 million (92.6% annual
growth)
Europe:
Eastern Europe 289 million (48.9% annual growth)
Western Europe 426 million (8.1% annual growth)
Middle East:
51.4 million (63.5% annual
growth)
71
Evolution to 3G
Transmisión de Datos Multimedia - Master IC 2006/2007
Drivers: Capacity, Data Speed, Cost
Expected market share
TDMA
GSM
EDGE
GPRS
cdmaOne
2G
3GPP Core
Network
WCDMA
PDC
CDMA2000
1x
First Step into 3G
EDGE
Evolution
CDMA2000
1x EV/DO
3G phase 1
90%
HSDPA/HSUPA
CDMA2000
EV/DO Rev A
10%
Evolved 3G
72
3G: Technology Summary
Technology Convergence on Wideband-CDMA
 CDMA 2000
Transmisión de Datos Multimedia - Master IC 2006/2007





Successor to CDMA IS-95, 4 core standards – 1xRTT, 1x EV-DO, 1x EV-DV,
3xRTT
1xRTT provides 2x voice capacity increase over IS-95 and a peak data rate
of 144kbps
EV-DO Rev A provide peak data rates of 3.1 downlink / 1.8 uplink (800kbps
typical)
UMTS



Successor to GSM, based on W-CDMA
Peak data rates of up to 1920kbps (384kbps typical)
HSDPA peak data rate of up to 14.4Mbps
73
3G: Winners & Losers ??
Transmisión de Datos Multimedia - Master IC 2006/2007

UMTS




Huge delays (terminals availability)
Exorbitant license fees
Confusing pricing strategies & lack of compelling services
Clear evolution path
 HSxPA (Peak Data Rates), LTE (Network Simplification)

CDMA2000



Early adoption (Korea)
Compelling peak data rates (EV-DO)
Unclear evolution path
 3xRTT? WIMAX?
74
UMTS Growth
Transmisión de Datos Multimedia - Master IC 2006/2007
Subscriber Penetration
Over 55 million
WCDMA subs at 31
March 06
Approaching 140%
yearly growth
Over 3 million adds
monthly in last 6
months
WCDMA gained over
10% share of mobile
growth in Asia Q1 06
WCDMA gained 1 in 3
new connections in
Western Europe in Q1
06
75
Transmisión de Datos Multimedia - Master IC 2006/2007
Global Subscriber Counts
2.5 Bn
GSM
2 Bn
1.5 Bn
Note:
GSM Emerging Market Handset (EMH) initiative = 80% of Global Population
with Wireless Service by 2010, based on sub $30 handsets
17 countries targeted = 1.8 Bn people ; not included in current sub counts
W-CDMA
1 Bn
0.5 Bn
CDMA
PHS
0
2006
2007
2008
2009
2010
2011
76
…and Beyond
Technology Convergence on OFDM (Orthogonal Frequency
Division Multiple Access)
 WIMAX
Transmisión de Datos Multimedia - Master IC 2006/2007



Standardized by IEEE 802.16, evolution of 802.11 (Wi-Fi)
Improved bandwidth, encryption and coverage over WiFi
 Theoretical peak data rates of 70Mbps (practical peak ~2Mbps)




Improved QoS better enables applications such as VoIP or IPTV
Ideal application is for “last mile” connectivity to the home or business
Intel plans to embed WiMAX chips as part of ‘Intel Inside’
L3GTE/HSOPA




Early standardization work starts in 3GPP R8
Improved bandwidth, latency over UMTS/HSxPA
Radio technology based on MIMO-OFDM, peak data rates of up to 70Mbps
Network simplification
77
Transmisión de Datos Multimedia - Master IC 2006/2007
Market Segments
Voice
Cellular
Broadband
Mobile
2.5G
WiMAX 16e
HSDPA to OFDM
EV-DO to OFDM
Local
WiFi
Cordless
802.11a/b/g
802.11n MIMO
Mesh
Fixed
POTS
Dialup
WiMAX 16d
DSL / Cable
78
Transmisión de Datos Multimedia - Master IC 2006/2007
Network Convergence - IMS
Unlicensed Mobile Access (UMA) and the IP Multimedia Subsystem (IMS) -- two standard architectures under the 3GPP
umbrella -- both support fixed-mobile convergence (FMC). But their approaches to FMC have little in common. UMA is a
highly constrained approach to a single service -- dual-mode access to GSM networks -- while IMS is an open platform for
all types of services and all types of networks. UMA offers mobile network operators (MNOs) a quick fix, but IMS promises
profitable new services and sustainable growth for all service providers.
Access
Network
PDG
WLAN
Media
Resources
Applications
Multimedia
Services
Messaging
Services
Web / WAP
Services
Audio/
Video
Streaming
Services
GGSN
Service Control
GPRS
UMTS
ASN
CSN
WiMAX
MRF
HSS/
AAA
ASN
ASGW
EASGW
Presence / GLMS
TDM & Packet
Interworking
Call
Session
Controller
R4
CDMA
PSTN
MGCF
(CS2000)
PDF
MG15000
HSOPA
OFDM/MIMO
ASG
IP/MPLS Core
Peer IP
Network
BRAS
79
Market Trends
Transmisión de Datos Multimedia - Master IC 2006/2007

Media Convergence – Multiple Play





Dual Play: High-Speed Internet & Fixed Line
Triple Play: Dual Play + TV
Quadruple Play: Triple Play + Wireless
Challenge: Consolidated Invoice and Price Points
Fixed Mobile Convergence

Dual Mode connectivity
 Cellular / Cordless (DECT, ADSL/Bluetooth)
 WLAN / WWAN


Challenge: Technology standardization
MVNO – Mobile Virtual Network Operator




Wireless Service Reseller, wholesales access from wireless operators
Discount & Lifestyle MVNO’s
Segment, Product, Utilization Driven
Challenge: Market Saturation & Service Differentiation
80
Market Trends (continued)
Transmisión de Datos Multimedia - Master IC 2006/2007

M-Commerce – Electronic Commerce using Mobile Phones





Leverage ubiquity of mobile phones to make transactions
Current payment methods: premium calling #’s, phone bill invoice, credit
card
Strong interest in key industries: banking, sports & entertainment, travel,
retail
Challenge: Security, Terminal Capabilities, Access Speeds
Multimedia – use of several media types to convey information


Effective information delivery across many disciplines: art, education,
telecommunications, medicine
IMS enables multimedia services for mobile users
 VoIP


Challenge: User Interface, Form Factor, lack of “killer app”
Presence – Always on, always connected




Combine Mobility & Reachability
Effectively bring Popularity of IM to mobile phones (AOL, Yahoo!, MSN,
Skype)
Opportunity for standardization & interworking based on SIP/SIMPLE
Challenge: Standardization & always on connectivity
81
Tema 1: Tecnologías de red.
Estructura
de Internet
Redes “core”


SONET
DWDM
Redes



de acceso
Redes cableadas: Ethernet et al.
Redes inalámbricas: IEEE 802.11 et al.
Otras tecnologías
Transmisión de Datos Multimedia - Master IC 2006/2007
Transmisión de Datos Multimedia - Master IC 2006/2007
Hybrid fiber-coaxial (HFC) architecture
Scientific-Atlanta CMTS

To deliver data services over a cable network:



one 6 MHz television channel that is in the 50 MHz to 750 MHz range is typically
allocated for downstream traffic to homes
one 6 MHz channel in the 5 MHz to 42 MHz band is used to carry upstream signals
A headend cable modem termination system (CMTS) communicates
through these channels with cable modems located in subscriber homes to
create a virtual LAN connection
83
Transmisión de Datos Multimedia - Master IC 2006/2007
Hybrid fiber-coaxial (HFC) architecture
www.twcarolina.com

The cable modem network only operates at Layers 1 and 2
84
Transmisión de Datos Multimedia - Master IC 2006/2007
Hybrid fiber-coaxial (HFC) architecture
Scientific-Atlanta
CMTS
An individual cable modem subscriber may experience access
speeds from 500 kbps to 2.5 Mbps, depending on the network
architecture and traffic load.
 If congestion does begin to occur due to high usage, cable operators
have the flexibility to add more bandwidth for data services.
 A cable operator can simply allocate an additional 6 MHz video channel
for high-speed data, which would double the downstream bandwidth
available to users.

85
Transmisión de Datos Multimedia - Master IC 2006/2007
What is DSL?
While considered an end-to-end solution, DSL only operates on the
local loop between the customer premises equipment (CPE) and the
DSL access multiplexer (DSLAM).
 A DSLAM is a device in the central office (CO) (sometimes) used to
terminate many Layer 1 DSL connections, such as dialup, cable,
wireless, and T1.

86
Transmisión de Datos Multimedia - Master IC 2006/2007
What is DSL?
DSL uses the high frequency range of up to about 1 MHz.
 For example, asymmetric digital subscriber line (ADSL) uses the
frequency range of about 20 kHz to 1MHz.




ADSL does not overlap the plain old telephone service (POTS) voice frequency range.
(300 – 3,400 Hz)
POTS and ADSL service can coexist over the same wire.
Other DSL variants like single-line digital subscriber line (SDSL) use
a frequency range that overlaps the POTS voice frequency range.

POTS and SDSL service cannot coexist over the same wire.
87
Transmisión de Datos Multimedia - Master IC 2006/2007
DSL limitations

The distance from CO to the DSL CPE must be considered.

The longer the distance, the lower the speed.
The gauge of wire used in the local loop is important.
 Thicker wire gauge supports higher speed.

88
Transmisión de Datos Multimedia - Master IC 2006/2007
ADSL
An installer must check with the service provider to determine which
modulation technique is being used.
 The modulation method used must be matched between the ADSL CPE
(DSL Modem) and the ADSL modems on the DSLAM.

89
ADSL and POTS coexistence
Transmisión de Datos Multimedia - Master IC 2006/2007
www.consultronics.com/ psts450.htm
There is a POTS splitter at the central office (CO) (or at home) to split
up the POTS called voice and ADSL called data traffic.
 The POTS traffic goes to the voice switch in the CO, and the ADSL traffic
goes to the DSLAM in the CO.
 ADSL offloads the data or modem traffic from the voice switch and
keeps analog POTS separate from data.

90