Future Access Networking

Saemundur E. ThorsteinssonIceland Telecom

Research Department

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Overview• The Eurescom FAN and Anfina Projects• FAN Rationale• Bandwidth Demand• Two Access Network Segments

– Backhaul technologies– Drop technologies

• Quality of Service in the Access Network• Role of Ethernet• Economic considerations• Vision of the Future Access Network

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The FAN project• FAN (Future Access Networks) was a Eurescom Study

– finished in 2002– European Intitute for Research and Strategic Studies in

Telecommunications

• Participants

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The Anfina Project

• Anfina – Access Networks control Functions and

Interfaces in NGN Architectures – Also a Eurescom study – will be finished by end of 2003

• Participants

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FAN Rationale

• IP dominates the traffic– Future Services are IP based– Current Services migrate to IP (e.g.VoIP)– Convergence of the Services in IP

• Ethernet becomes the standard customer interface

• Bandwidth demands increasing• Dynamic bandwidth allocation required

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FAN Rationale

• Currently deployed telecom access network solutions are – mostly TDM-based (for narrowband traffic, e.g.

legacy telephony) – ATM-based (broadband traffic, e.g. ADSL)

• The result is a gap between access network technology and service evolution trends

• When and how should the operators upgrade their AN ?

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Bandwidth demand of homes

1

10

100

1000

10000

1985 1990 1995 2000 2005 2010

Year

Bit

rate

[kb

/s]

According to Moore'slawActual modemconnection speedADSL 256 kb/s

ADSL 512 kb/s

•Exponential growth, doubling every 23 months

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Factors increasing the bitrate

• Video communications– Streaming video on the Internet– Video on Demand– Video telephony and conferencing– Digital cameras and camcorders

• Increasing need for exchanging pictures and videos

• SAN = Storage Area Networking– Data storage

• Files grow through the years

– Enhanced data security– High speed connections required for tolerable service

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500

1000

1500

2000

2500

3000

2001 2000 2003 2002 2005 2004

Bitrate [kb/s]

Year

• Advancement in video encoding technology– Less bitrate required for same video quality– Makes Video over ADSL interesting

Video encoding

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Two Segments - Drop and Backhaul

AG

AG

Backhaul Network

SN

SN

SN

Access Network

Drop Segment

Drop Segment

NT

NT

DATA Network ATM Network

DATA Network IP Network

DATA Network PSTNNetwork

DATA Network Copper

DATA Network Cable

DATA Network Radio

DATA Network Fibre

DATA Network Backhaul Segment

Service Node or Core Network Interface

e.g. BRAS

NT – Network Termination

AG - Aggregation Node

SN – Service Node

Aggregation Node e.g. DSLAM

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Drop Segment

• From the customer to the aggregation node is characterised by– Diversity of Transmission media (copper, fibre, cable,

radio)– Diversity of Systems based on various technologies

(TDM, ATM, IP,…)– Different Aggregation Node concepts – Not interoperable

• This situation remains probably for a long time, but could evolve smoothly by substituting or deploying new technologies, e.g. ATM-based ADSL --> Ethernet-based ADSL or VDSL

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Technology Comments

ATM

connection less, e.g. Ethernet

CopperADSL x Nearly only ATM but IP-based DSLAMS are available nowSHDSL x (x) open, but ATM dominatingVDSL x x packet based, FS-VDSL propose ATM in the first stepCoaxDOCSIS x DOCSIS deployment dominatesDVB xRadio

x up to Release 4 & 5x Release 6

WLAN x IP native (IEEE802.11) dominating TechnologyHiperLAN/2 x No product yet on the marketBWA x x Hiper Access(ATM), IEEE802.16 (DOCSIS like)FibreAPON x Standard basedEPON x IP native, but no standard yetOptical Ethernet x IP native, wide deployment in the Data worldATM over SDH x Inefficent IP transportPOS x Expensive

Layer 2

UMTS

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Backhaul Segment

• From the Aggregation Node to the Service node

– Dedicated to the individual services and/or drop technologies

– Diversity of systems based on various technologies (TDM, SDH, ATM, IP,)

– Not interoperable

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Backhaul Segment

• Expected evolutions & potential of cost savings by – Convergence of the Backhaul networks on common

optical platform– Integration of services by integration of different

drop technologies– Simplification of the protocol stack (Replacement of

IP/ATM/SDH by Ethernet

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Backhaul Segment

OpticalOptical

SDHSDH

ATMATM

IPIP

OpticalOptical

SDHSDH

IPIP

OpticalOptical

ATMATM

IPIP

OpticalOptical

EthernetEthernet

IPIP

Reduced complexity and cost

Legacy situation

Frequent situation

Frequent situation

Upcomingsituation

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EthernetFuture Development

Source: Extreme Networks

Data

Voice

LAN Metro WAN

10GbE

QoS

(ATM)

SONET/SDH

(ATM)

SONET/SDH

EFMMPLS

EthernetEthernet

EFM: Ethernet in the First MileEFM: Ethernet in the First Mile

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Access Network evolutionFuture AccessCurrent Access

Terminals off remoteMainframe

ADM

MUX

ATM/FR

Equipment StackatCO

Customer Premise

PABX

PBX Extensions

Multiple Analog Lines for Voice

Router

LAN

DSLAM

DLC

VoDSLGW

Class 5

IP/MPLS Backbone

Softswitch Call Control

Packet-Based

Optimized for the Internet Protocol

Enabled by…. Multi-Protocol Label Switching (MPLS) Distributed Call-Agent (i.e. SoftSwitch)

Services

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Quality of Service, QoS • QoS guarantees must be offered in Access Networks

– Services have different requirements

Source: Tanenbaum, Computer Networks, 4th ed.

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Quality of Service

• Access Networks need to support Service Level Agreement management– To enable flexible/dynamic service provisioning– For dynamic bandwidth allocation

• AN need to segregate traffic between customers and/or services.– To enable security and confidentiality– To enable different QoS treatment

• AN need to support multicast (e.g. for TV-broadcast services)

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Quality of service

• To support IP QoS, there is a need to reflect some “IP and application knowledge” in layer 1 and 2 of the AN (in various equipment).– New developments in IP/Ethernet technology increase the

capabilities of QoS– Differentiated service integration

• The access is not the dumb part of the network any longer.

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• Layer 2 Ethernet Switching – Full Duplex operation & high bit rates : 10, 100, 1000

Mbit/s– Increasing switching capacity – Use of VLAN (Virtual Local Area Network) :

• Based on IEEE 802.1Q (VLAN Tag)• Enables “waterproof” separation of different network

traffic domains• IEEE 802.1P enables prioritisation, queuing, traffic shaping

and policing

– Various criteria can be used to relate traffic to a VLAN : per port (of switch), per MAC address, per IP address, per Layer 3-type protocol, per service…

IP-based contenders in the AN

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• Layer 2,5 MPLS (Multi Protocol Label Switching)– MPLS brings the advantages of connection oriented

networks to connectionless networks • Adds intelligent traffic handling to the access network• Close integration with IP • MPLS adds QoS to IP networks in combination with Diffserv or

Intserv• Needed for multi-service networks and particularly for voice

services

– IP/MPLS advantages• One protocol and technology from the access to the core• Enable VPN services (Virtual Private Networks)• Simplified management throughout entire network• Flexible service creation, faster service roll-out

IP-based contenders in the AN

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Economic considerations Gigabit Ethernet vs ATM/SDH, SDH

Electronics/Optics BW mgmt. & Annual maint. BW on $/Mbps provisioning upgrades demand

Yes5:1 – 8:15:18:1 - 13:1GbE advantage

Yes$150-450$1k$1-3IP/Ethernet

Very difficult$750-$3750$5k$6-35IP/SDH

Very difficult$750-$3750$5k$8-40IP/ATM/SDH

Source: Yipes, Dell ‘Oro, Yankee Group, Extreme Networks, Juniper Networks Assumes a regional network with fibre hubs and 10 rings

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Technology Price evolution

0%

20%

40%

60%

80%

100%

120%

2001 2002 2003 2004 2005 2006 2007

Pri

ce e

volu

tio

n

ATM

Ethernet

SDH

Infra-structure

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Model of the FAN

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FAN drop segment

• Will be characterised by– Ethernet interfaces– Dependence on medium and technology– Shorter distances, as Aggregation Node is moving

closer to the subscriber– (re-)use of copper pair, wherever feasible– New fibre deployment

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FAN backhaul segment

• IP-based• Optical

– (Gigabit Ethernet, APON, EPON)

• Mesh- (L2 switching) or Ring- (with RPR) topologies

• Will use MPLS (e.g. over GbE) as an ATM & IP convergence solution

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Thank you

• Further information– http://www.eurescom.de/public/projects/P1100-series

/P1117/– Deliverable 1 (IP based access technologies and QoS)

is publicly available

Questions?

Questions?