Transcript Towards Wireless Overlay Network Architectures

Berkeley-Helsinki Summer Course
Lecture #1: Course Overview
Randy H. Katz
Computer Science Division
Electrical Engineering and Computer Science Department
University of California
Berkeley, CA 94720-1776
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Outline
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Course Content
Technology Trends
Evolution of the Internet
Business Trends
Implications and Issues
Summary and Conclusions
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Outline
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Course Content
Technology Trends
Evolution of the Internet
Business Trends
Implications and Issues
Summary and Conclusions
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What is this Course About?
• Emerging, yet still developing, view of a new
kind of communications-oriented middleware
– Rapid development/deployment of new services & apps
– Delivered to radically different end devices (phone,
computer, info appliance) over diverse access networks
(PSTN, LAN, Wireless, Cellular, DSL, Cable, Satellite)
– Exploiting Internet-based technology core: clients/server,
applications level routers, TCP/IP protocols, Web/XML
formats
– Beyond traditional “call processing” model: client-proxyserver plus application-level partitioning
– Built upon a new business model being driven by the
evolution of the Internet: traditional “managed” networks
and services versus emerging “overlay” networks and
services structured on top of and outside of the above
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Course Lectures
Berkeley, 29-30 May
Espoo, 9, 11 June
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Course Overview
Telecomm Service Architecture
Middleware Architecture
CORBA/OMG
UMTS/3GPP
IP Mobility
Net Measurement & Monitoring
Internet Economics
IP QoS
SLAs and Clearing Houses
Context Awareness
Introspection & Adaptation
Security in Mobile Computing
Service Discovery Protocols
Content Distribution Protocols
Wrap-up Summary
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A Possible Service
Architecture
Prototype Applications: Universal In-Box,
Context-Aware UI, Group Collaboration
Context-Awareness Services: Activity Tracking/Coordination,
Preferences Specification/Interpretation
Adaptation Services: Introspection,
Tacit Information Extraction/Organization
Wide-Area Services: Discovery, Mobility, Trust, Availability
Performance Measurement and Monitoring
“Core” Wide-Area Network
Edge/Access Networks
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Nokia’s mPlatform
Architecture
Operational
Support
Provisioning
Self-Care
Operator Care
Billing Data
Collection
Sys Monitoring
Perf Monitoring
Statistics
Common Enabling Application Functions
Presentation
Manager
Operator
Manager
Audit Manager
(Billing)
Navigation
Manager
Notification
Manager
Security
Manager
Session
Manager
Personalization
Manager
Scenario
Manager
Access Functions
Subscriber
Subscriber
Service
Access Control Authentication Access Control
Process
WAP & PDA
Handling
Proxy
Firewall
Network
Connectivity
Load
Balancing
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ICEBERG Architecture
Access Network
Plane
PSTN
GSM
IAP IAP IAP
ICEBERG
Network
Plane
Pager
CA
PR
PAC
IAP
APC
NMS
A
SF iPOP
NY iPOP
IAP
SF iPOP
B
NY iPOP
Clearing House
ISP Plane
IAP
ISP1
ISP2
• iPOP: Clustered
computing environ.
• Call Agent: handles
signaling, one per
device per call party
ISP3
• Name Mapping Service: Maps ICEBERG unique ID  service end point
• Preference Registry / Personal Activity Coordinator: user profile / user tracking
• Automatic Path Creation service: creates transcoding datapath between endpoints
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One Operator’s Viewpoint
Pricing
Structure
Customer
Service
HLR
Distribution
Packaging
Marketing & Sales
Billing
Apps
Charging
3rd Party
Apps
Services
Content
Support Systems
Service Domain
Data Center
Data Storage
BS
Radio Access
BS
Network
Spectrum
QoS Cap
Capacity
On-Demand
Processing Cap
Local Radio
Access
Transport
Core Network
Capacity
On-Demand
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Outline
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Course Content
Technology Trends
Evolution of the Internet
Business Trends
Implications and Issues
Summary and Conclusions
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Technology Trends
• Computing
– Convergence, Divergence, Scale
• Networks
– Internet vs. Telephone Network
– Wireless/Mobile Access
• Services
– E-commerce, M-commerce, Content
• Architecture
– Integrated (“Closed”) vs. Composed (“Open”) Content,
Distribution, Access Architecture
– Managed vs. Overlay Networks and Services
– Competitive vs. Cooperative Service Providers
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Convergence?
First Color TV
Broadcast, 1953
HBO Launched,
1972
Telephone,
1876
Interactive TV,
1990
Early Wireless
Phones, 1978
Computer
+ Modem
1957
First PC
Altair,
1974
IBM
PC,
1981
Handheld Portable
Phones, 1990
Apple
Apple
IBM
Mac, Powerbook, Thinkpad,
1984
1990
1992
Eniac, 1947
HP
Palmtop,
1991
Pentium
PC, 1993
Apple
Newton,
1993
Red Herring, 10/99
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Divergence!
Atari Home
Pong, 1972
Pentium
PC, 1993
Game Consoles
Personal Digital Assistants
Digital VCRs (TiVo, ReplayTV)
Communicators
Smart Telephones
E-Toys (Furby, Aibo)
Network
Computer,
1996
Free
PC, 1999
Sega
Dreamcast,
1999
Internet-enabled
Smart Phones,
1999
Pentium II
PC, 1997
Apple
iMac, 1998
Palm VII
PDA, 1999
Proliferation of diverse
end devices and access networks
Red Herring, 10/99
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Convergence: Post-PC
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Not about gadgets or access technologies
About services and applications
Increasing, not decreasing, diversity
Enabled by computing embedded in
communications fabric
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The Shape of Things Now
• Siemens SL45
– A cellular phone with voice
command, voice dialing, intelligent
text for short messages
– An MP3 player & headset
– A digital voice recorder
– Supports “Mobile Internet” with a
built-in WAP Browser
– Can store
» 45 minutes of music
» 5 hours of voice notes
» “Unlimited” addresses/phone
numbers
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The Shape of Things Now
• Kyocera QCP 6035
– Palm OS/CDMA
– Palm PIM Applications
– Supports “Mobile Internet” with a
built-in WAP Browser
– 8 MBytes
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Societal-Scale Systems
New System Architectures
New Enabled Applications
Diverse, Connected, Physical,
Virtual, Fluid
“Server”
“Client”
Massive Cluster
Gigabit Ethernet
Clusters
Scalable, Reliable,
Secure Services
Information
Appliances
MEMS
BioMonitoring
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What is the Internet?
“It’s the TCP/IP Protocol Stack”
Applications
• Applications
Middleware
Services
“Narrow
Waist”
TCP/IP
Transport Services and
Representation Standards
Network
Technology
Substrate
Access
Technologies
Open Data Network
Bearer Service
Where is the next “narrow waist”?
– Web
– Email
– Video/Audio
• TCP/IP
• Access Technologies
– Ethernet (LAN)
– Wireless (LMDS, WLAN,
Cellular)
– Cable
– ADSL
– Satellite
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Telephony Evolution
• Mobility/Wireless driving end-to-end digitization of
the telephony system
– Shift towards IP-based infrastructure (e.g., Motorola + CISCO)
• Converged Services
– AT&T
» Cell Phone, Telephone, ISP, Video on Demand (Cable)
» Universal Billing Systems
– Sprint: $0.05/min local/long distance, wired/wireless
• Computer-Telephony Integration
– Call Centers, Software-based PBXs, PSTN By-Pass
– Consumer-to-Business E-commerce (e.g., Lands End)
– Speech-Enabled Services (e.g., “Concierge”)
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Internet vs. Telephone Net
• Strengths
– Intelligence at ends
– Decentralized control
– Operates over heterogeneous
access technologies
• Weaknesses
– No differential service
– Variable performance delay
– New functions difficult to
add since end nodes must be
upgraded
– No trusted infrastructure
• Strengths
– No end-point intelligence
– Heterogeneous devices
– Excellent voice performance
• Weaknesses
– Achieves performance by
overallocating resources
– Difficult to add new services
to “Intelligent Network” due
to complex call model
– Expensive approach for
reliability
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Wireless Access Technologies
Wireless Communications
Consumer
Residential
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WLL
LMDS
MMDS
Satellite
HomeRF
Cellular/PCS
— 2nd Gen
(GSM,
TDMA,
CDMA)
— 3rd Gen
(W-CDMA)
Business
Satellite
— DirecTV/PC
— Spaceway,
Teledesic
— Globalstar,
JSAT,
ICO
WLAN
Mobile Data
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802.11
HomeRF
BlueTooth
IrDA
HiPerLAN
ARDIS
Mobitex
Omnitracs
CDPD, GSM
SMS, Edge,
GPRS, WAP
— NTT I-Mode
— Palm VII
PMR/SMR
WPBX
— Moto iDen
(Nextel)
• Broadband Wireless data poised to take off
• High degree of diversity among access technologies
• Convergence of consumer and business needs
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Design Space of Terrestrial
Wireless Performance
Mbps
Wired
100
10
1
0.1
0.01
Wireless
Local Area
Networks
60 GHz
100 m range
“Mobile Broadband
Systems”
Cordless
“Universal Mobile
Telecomms Systems”
(UMTS)
Cellular
Office or
Room
Building
Indoors
Stationary
Walking
Outdoors
Vehicle
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Access Networks: One View
(21 million I-Mode users?)
• Only 15% of personal consumer devices will be
able to access Internet within 5 years
(embedded micro-browser and e-mail client)
– 5 years: Internet access remains a niche for mobile access
– 10 years: Internet access becomes ubiquitous
– Placed-based vs. passenger-based vs. personal access
• BUT 50% of US hotel rooms will have Internet
access within 5 years!
• Situational and time sensitive services will
dominate (directions, maps, e-mail, weather
information, traffic updates)
• 2007: 7 million autos equipped with driver
information systems
Jupiter Communications: “Internet Everywhere”
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Cellular Services Most Often
Requested
After basic wireless telephony service
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Call Forwarding
Paging
Internet/E-Mail
Traffic/Weather
Conference Calling
News
37%
33%
24%
Data
15% Applications
13%
3%
Source: CTIA Web Page
Peter D. Hart Research Associates, March 1997
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Satellite Technology
Back Link
(Satellite Phone)
Satellite Broadcast Networks
Media Stream
Request
NOC
Internet
Request
Media Browser
Characteristics
. Broadcast
. Bandwidth on-demand
. Ubiquitous
Back Link Channel
(Cellular / PCS Network)
Request
Media Browser
Multimedia
Data Sources
Back Link Channel
(Phone, Cable Line)
Media Browser
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Services and Applications:
E-Commerce
• Consumer Services
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Consumer-driven QoS: improved Web access “experience”
Converged digital video + web content (e.g., HVML)
Unified billing: pay-per-view movie plus ad-induced pizza purchase
Content delivery: file mover/software upgrades/digital audio/video
Infrastructure storage: back-up, photos, mp3s, videos, TV tapings
• Consumer-to-Business Services
– Web-based + (IP-based) Telephone
– New kinds of integrated call centers: e.g., Lands End
• M-Commerce
– Location-sensitive ad insertion
– Unified billing for telecom access + purchases
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Outline
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Course Content
Technology Trends
Evolution of the Internet
Business Trends
Implications and Issues
Summary and Conclusions
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Internet Evolution
ARPANet
SATNet
PRNet
1965
TCP/IP
1975
Web Hosting
Multiple ISPs
Internet2 Backbone
Internet Exchanges
NSFNet
Deregulation & ISP
Commercialization ASP
AIP
WWW
1985
1995
2005
Application Hosting
ASP: Application Service Provider
AIP: Application Infrastructure
Provider (e-commerce tookit, etc.)
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Network “Cloud”
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Regional Nets + Backbone
Regional
Net
Regional
Net
Regional
Net
Backbone
Regional
Net
Regional
Net
LAN
LAN
Regional
Net
LAN
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Backbones + NAPs + ISPs
ISP
ISP
ISP
NAP
Backbones
Business
ISP
LAN
LAN
NAP
ISP
Consumer
ISP
LAN
Dial-up
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Core Networks + Access Networks
DSL
Always on
Cable
Head Ends
@home
Covad
Cingular
Cell
Cell
Cell
LAN
NAP
Core
Networks
NAP
ISP
Satellite
Fixed Wireless
Sprint
LAN
AOL
LAN
Dial-up
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Computers Inside the Core
DSL
Always on
Cable
Head Ends
@home
Covad
Cingular
Cell
Cell
Cell
LAN
NAP
NAP
ISP
Satellite
Fixed Wireless
Sprint
LAN
AOL
LAN
Dial-up
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Outline
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Course Content
Technology Trends
Evolution of the Internet
Business Trends
Implications and Issues
Summary and Conclusions
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Emerging Internet Service
Business Model
Applications
(Portals, E-Commerce,
E-Tainment, Media)
Appl Infrastructure Services
(Distribution, Caching,
Searching, Hosting)
AIP
ISV
Application-specific Servers
(Streaming Media, Transformation)
ASP
Internet
Data Centers
ISP
CLEC
Application-specific
Overlay Networks
(Multicast Tunnels, Mgmt Svrcs)
Global Packet Network
Internetworking
(Connectivity)
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A New Kind of Internet
Web Site Caching
Comparison Shopping
Interactive TV Guide
Local Ad Insertion
Streaming Media
Application
Services
Customer J
Terminal Equipment &
Access Network
Applications
Regional Communications
PC, Set-top Box.
Smart Phone, Game
Console, E-toys
Web, E-mail, Chat,
E-commerce,
E-tainment
ISP
Web Hosting
Server “Platform”
ISP Caching
Search Engine
Server Computing
Wide-Area Communications
Infrastructure
Services
High Performance
Backbone
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Open vs. Closed Access to Services
Covad
DSL
Time/Warner
Roadrunner
AOL Dial-up
AT&T Cable
Access
Cable, DSL, MMDS,
LMDS, Satellite
CNCX
AOL
@Home
Local Network
Management
ISP
Williams
AOL
@Home
Routing &
Distribution
Backbone
Provider
Web
AOL/Netscape
Time/Warner
Excite
Content
Portal
Web Sites
• Closed end-to-end pipe: optimized performance
• But companies developing compelling infrastructure
technology that any content provider or ISP can adopt
• Closed system can’t benefit from these
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Context for Cooperation
Among Service Providers
• Huge Expense of 3G Mobile Telecomms Infrastructures
– European spectrum auctions: 50 billion ECU and counting
– Capital outlays likely to match spectrum expenses, all before the first
ECU of revenue!
– Wireless operators in complex web of business relationships and partial
ownerships of networks around the world
• Compelling motivation for collaborative deployment of
wireless infrastructure
– Happening already several places in Europe & Asia
• Same for cooperative service infrastructure?
– Mobile Virtual Network Operator (MVNO)
– Internet transport providers vigorously complete
– But some cooperation also emerging: Content Dissemination Alliances
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Any Way to Build
a Network?
• Partitioning of frequencies independent of actual
subscriber density
– Successful operator oversubscribe resources, while less popular
providers retain excess capacity
– Different flavor of roaming: among collocated/competing service
providing
• Duplicate antenna sites
– Serious problem given community resistance
• Redundant backhaul networks
– Limited economies of scale
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The Case for Horizontal
Architectures
“The new rules for success will be to provide one
part of the puzzle and to cooperate with
other suppliers to create the complete
solutions that customers require. ... [V]ertical
integration breaks down when innovation
speeds up. The big telecoms firms that will
win back investor confidence soonest will be
those with the courage to rip apart their
monolithic structure along functional layers,
to swap size for speed and to embrace rather
than fear disruptive technologies.”
The Economist Magazine, 16 December 2000
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Feasible Alternative: Horizontal
Competition vs. Vertical Integration
• Service Operators “own” the customer, provide
“brand”, issue/collect the bills
• Independent Backhaul Operators
• Independent Antenna Site Operators
• Independent Owners of the Spectrum
• Microscale auctions/leases of network
resources
• Emerging concept of Virtual Operators
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Business as Usual:
Vertical Integration
PBMS
Sprint
Access
Network
Backhaul
Network
Access
Network
Backhaul
Network
PSTN Network
(Multiservice Provider today)
Internet
(Multiservice Provider today)
• Each operator owns own frequencies, cell sites,
backhaul network
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Business Unusual:
Horizontal Competition
Sprint “leases”
frequencies from
PBMS, on-demand,
based on the density
of its subscribers
“Mom&Pop”
Cell Site
Operators
Access Network
Access Network
Backhaul
Network
PSTN
Network
Backhaul
Network
Internet
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Virtual
Operator
• MVNO: Virgin Mobile and One2One in UK
– Distinguish based on marketing and billing plan innovations
– VM competes for subscribers but uses One2One’s network
• “Operators without subscribers”: local premises
deploy own access infrastructure
– Better coverage/more rapid build out of network
– Deployments in airports, hotels, conference centers, office
buildings, campuses, …
• Overlay service provider (e.g., PBMS) vs.
organizational service provider (e.g., UCB IS&T)
– Single bill/settle with service participants
• Support for confederated/virtual devices
– Mini-BS for cellular/data + WLAN for high rate data
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Outline
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Course Content
Technology Trends
Evolution of the Internet
Business Trends
Implications and Issues
Summary and Conclusions
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What will be the Next Generation
of Driving Applications?
• Location-aware/context-aware information delivery
and presentation
– Extends UniIn-Box: loc-based, exploits calendar info
– Mediation to translate formats
• IP Telephony, Packet VoD, Teleconferencing
– Streaming media, multicast-based
– Bandwidth, latency, jitter, lose rate constraints
– Clearinghouse provisioning
• Event Delivery for Distributed Applications
– Performance/reliability constrained messaging
– Management of Content Delivery Networks, Distributed Service
architecture?
• Interactive Games? Distributed Storage
(OceanStore)? Telemetry?
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What Will Be the Next Generation
Operational Environment?
• Virtual Operators/Service Provider (VOSP)
– Provide service to end users with no server/network
infrastructure of own
– Independent “Path” providers (e.g., ISPs) and Server providers
(e.g., Internet Data Centers)
– Many-to-many relationship between VOSP and Path/Server
Providers
• Confederated Service Provider
– Service-level peering: sharing of paths and servers to deploy
end-to-end service with performance and reliability constraints
• Note: Akamai runs “the world’s largest service
network” without owning a network!
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Alternative Operational
Environments
• Confederation Model
– Providers share (limited) information about topology, server
location, path performance
– Cooperatively collect internal information and share
• Overlay Model
– Reverse-engineer topology and intra-cloud performance
– Collection done by brokers outside of the cloud
• SLAs, Verification, Maintenance of Trust
Relationships different in the two models
• Is there an operational/performance advantage to
the Confederation Model?
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Open Issues/Questions
• Traditional Overlay Networks
– Server (“Application Level Router”) Placement
» For scaling, reliability, load balancing, latency
» Where? Network topology discovery: WAN Core,
Metro/Regional, Access Networks
– Choice of Inter-Server “Paths”
» For server-to-server latency/bandwidth/loss rate
» Predictable/verifiable network performance (intra-ISP
SLA)
– Redirection Mechanisms
» Random, round-robin, load-informed redirection
» Net vs. server as bottleneck
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Open Issues/Questions
• Performance-constrained Service Placement
– Separation of Service, Server, Service Path
» Assume “Server Centers” known, can be “discovered” (how
does OceanStore deal with this?), or register with a Service
Placement Service (SPS)
» How is Service named, described, performance constraints
expressed, and registered?
» How is app/service-specific performance measured and made
known to Service Placement Service?
– Brokering between Server Centers and Service Creator, Path
Provider and Service Creator
• If core network bandwidth becomes infinite and
“free”, does it matter where services are placed?
– Latency reduction vs. economies of centralized management
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Emerging Reference Architecture
Constraint
Specification
Distributed Application
Marshal Resources
Based on Economic Constraints
Service Registration
Service Placement Service
Path Broker
Server Broker
Perf Measurement Service
Verify
SLAs
Path
Provider
(ISP
Cloud)
Path
Provider
(ISP
Path Provider (ISPCloud)
Cloud)
Adapt
Service
Redirection
Pricing
Service
Server Registration
Advertisement
Registration
Path
Provider
(ISP
Cloud)
Path
Provider
(ISP
Cloud)
Server Center Provider
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Methodological Framework
• Problem: performing scaled, wide-area networking
studies in the current Internet environment
• Possible Solution: Wide-area Network Emulation
– Virtual WAN (VWAN) on Large-scale Multicomputer Testbeds
– Build operational model on top of VWAN
» Traffic generation and measurement infrastructure
» Build Confederation and Overlay operational models
» What part of mechanisms for measurement, negotiation,
registration, redirection, etc. the same and which are
different?
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Outline
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Course Content
Technology Trends
Evolution of the Internet
Business Trends
Implications and Issues
Summary and Conclusions
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Challenges for the Post-PC Era
• Services spanning access networks, to achieve high
performance and manage diversity of end devices
• Not about specific Information Appliances
• Builds on the New Internet: multiple applicationspecific “overlay” networks, with new kinds of
service-level peering
• Pervasive support for services within “intelligent”
networks
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Automatic replication
Document routing to caches
Compression & mirroring
Data transformation
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Managing Edge Versus
Core Services
• Wide-area bandwidth efficiency
• Increasing b/w over access networks, but impedance
mismatch between core and access nets
• Fast response time (and more predictable)
• Opportunity to untegrate localized content
• Associated with client (actually ISP), not server
• Examples:
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Caching: exploits response time, b/w efficiency, high local b/w
Filtering: form of local content transformation
Internet TV: b/w efficiency, high local b/w, predictable response
Transformation: adapt content for end user/diverse access devices
Software Rental: sxploits high local b/w
Games, chat rooms, ….
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Yielding a New
Research Agenda
• New Definition of “Quality of Service”
– Perceived quality depends on services in the network
– Manage caches, redirection, NOT bandwidth
– Enable incorporation of localized content
• Bandwidth Issues
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Tier 1 ISP backbones rapidly moving towards OC 192 (9.6 gbs!)
Better interconnection: hops across ASs decreasing over time
Emerging broadband access networks: cable, DSL, ...
End-to-end latency/server load dominate performance
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IP Multicast, DNS, …
Rethinking the End-to-End Principle
Service/content-level peering, just like routing-level peering
Secure end-to-end connection compatible with service model?
• Supporting Old Services in the New Internet
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