1 Beyond Third Generation Beyond Third Generation Telecommunications Architectures: Telecommunications Architectures: The Convergence of Internet The Convergence of Internet Technology and Cellular Telephony Technology and Cellular Telephony Prof. Randy H. Katz EECS Department University of California, Berkeley Berkeley, CA 94720-1776 [email protected]http://www.cs.Berkeley.edu/~randy
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Beyond Third GenerationBeyond Third GenerationTelecommunications Architectures:Telecommunications Architectures:
The Convergence of InternetThe Convergence of InternetTechnology and Cellular TelephonyTechnology and Cellular Telephony
All Circuits Circuits to ISPs All Circuits Circuits to ISPs
5.0
5.0
6.7
6.7
4-5
2-4
3.8
na
43-47
45.0
31.7
52.3
17.7
14
20.8
na
Source: FCC (The Economist, 13 Sept 97)
Network Usage, Minutes
19
Will Trend Towards Data-Will Trend Towards Data-Centric Accelerate?Centric Accelerate?
• Sir William Preece, Chief of the British PostalSystem, 1876:
“The Americans may have need of the telephone, butwe do not. We have plenty of messenger boys.”
• Analogy with the Post Office– Telephones have largely replaced the personal letter– Posts used mainly for business-oriented
correspondence: documents (Fed-Express), bills(direct debit/e-commerce), advertising (WWW),delivery of merchandise (UPS)
– Email reduces number of telephone conversations– What will be the effect of the Internet/WWW?
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Will Trend Towards Data-Will Trend Towards Data-Centered Accelerate?Centered Accelerate?
• Many calls to obtain information are already beingreplaced by the WWW– E.g., Ordering Books– E.g., Ordering CDs– E.g., Fyte Trax Service– E.g., Package Tracking– E.g., Booking Flights– and so on
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Efficiencies of InteractionEfficiencies of Interaction
Source: McKinsey (The Economist, 13 Sept 97)
Search: Finding a High-Rate Certificate of DepositTelephoneWWWWWW w/ agent
Co-ordination: Reordering an Inventory ItemMailE-mailEDI
Monitoring: Updating an Equity PortfolioNewspaperWWWWWW w/ agent
25.0
10.0
1.0
Min
-60%
-90%
3.7
1.6
0.3
-57%
-81%
5.1
1.8
0.5
-65%
-72%
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Presentation OutlinePresentation Outline
• Comparison of Telecomm & Data Comm Industries• Voice-centric versus Data-centric Viewpoint
• Internet versus Telephone Technology• Implications Beyond the Third Generation
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What is the Internet?What is the Internet?
“Internet” refers to the global information system that -- (i) islogically linked together by a globally unique addressspace based on the Internet Protocol (IP) or itssubsequent extensions/follow-ons; (ii) is able to supportcommunications using the Transmission ControlProtocol/Internet Protocol (TCP/IP) Suite or itssubsequent extensions/follow-ons, and/or other IP-compatible protocols; and (iii) provides, uses or makesaccessible, either publicly or privately, high level serviceslayered on the communications and related infrastructuredescribed herein.
Federal Networking Council Resolution, 24 October 1995
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Today’s Internet TechnologyToday’s Internet Technology
• Strengths– Intelligence at the end
points; No state in thenetwork;
– Highly decentralized control– Enables operation over very
heterogeneous collection ofaccess technologies; fewassumptions about thenetwork necessary
overallocating resources– 3.4 KHz audio voice band
signal converted to 64 kbpsdigital representation
– Switching designdetermined by statistics ofcall traffic
– Difficult to add new servicesto the so-called “IntelligentNetwork” due to complexfeature interaction
– Expensive approach torobustness
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ATM: The Grand Convergence?ATM: The Grand Convergence?
• Strengths– Virtual circuits with call set-
up to manage scarceresources and achieve QoSguarantees
– Fixed/small size “cells” toenable fast switching
– Sophisticated statisticalmultiplexing mechanisms tomake possible variety oftraffic models
– Integrated services
• Weaknesses– Connection-orientation has
some problems with latencyand robust operation; everycell must follow same path inorder
– ATM unlikely to be a universalend-to-end technology,especially for data traffic inlocal area
– Quaranteed performance end-to-end in heterogeneousenvironments is lost
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Next Generation InternetNext Generation Internet
• “Integrated Services Packet Network (ISPN)”• Ubiquitous support for multipoint-to-multipoint
multicast communications• Built-in support for mobility and mobile route
optimization
• Resource allocation mechanisms based on RSVPsignaling– Performance promises rather than guarantees– Receivers initiate signaling; nice scaling properties– Soft state in the network allows robust recovery to
failure; protocol works around link and switch failures
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Next Generation InternetNext Generation Internet
• Microprocessor performance/software algorithmsnow sufficient for real-time encode/decode ofvideo and audio– Traditional telephony hardware operates at 64 kbps for
PCM coding– Mbone software audio coding at many rates
» 36 kbps ADPCM» 17 kbps GSM» 9 kbps LPC
Adequate video at 28.8 to 128 kbps» Scalable codecs» Layered video
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Next Generation InternetNext Generation Internet
• Real Time Protocol (RTP)– Application Level Framing– End nodes adapt audio/video streaming rates to what
the network can support
• Easy integration of new services like proxies– Hardware/software is not specialized– Easy to integrate distributed applications
• Solve performance problems by adding morebandwidth
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Internet TelephonyInternet Telephony
Local Call Local CallInternet
SF to Frankfurt via Internet Service: $0.28 per min via AT&T Long Distance: $1.25 per min
Analog Voice toPacket Data
Packet Data toAnalog Voice
Source: G-Cubed
Gateway Gateway
Why so Cheap?
Less expensive infrastructureCircumvents government-backed monopoliesExisting long distance tariffs far exceed costsWTO worldwide deregulation
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Internet TelephonyInternet Telephony
• Quality Issues: High Latencies, Dropped Packets– Solutions
» Deployment of private networks» Faster and scalable hardware reduces gateway latency» RSVP + H.323 + Reconstruction of lost packets + Better voice
coding at 8 kbps» VoIP: Voice over Internet Protocol Forum
• Integration of circuit-switched local infrastructurewith packet-switched wide-area infrastructure– Wide-area b/w is a commodity, not true for local access
» 1996-2000: 5X increase in Atlantic/Pacific cable capacity– Many leading telecomms already doing this
» Internet FAX services» Cheap way for RBOCs to get into long distance service
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U.S. Internet Telephony MarketU.S. Internet Telephony Market
1998 1999 2000 2001 2002 2003 20040
0.5
1
1.5
2
2.5
3
1998 1999 2000 2001 2002 2003 2004
SpentSavings
Source: Forrester Research (The Economist, 13 Sept 97)
NewRevenues
CostSavings
4% of U.S. Telephony Revenue
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Presentation OutlinePresentation Outline
• Comparison of Telecomm & Data Comm Industries• Voice-centric versus Data-centric Viewpoint
• Internet versus Telephone Technology• Implications Beyond the Third Generation
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Third GenerationThird GenerationTelecommunications ArchitecturesTelecommunications Architectures
High-tier
Low-tier
Satellite
High Mobility Low MobilityWide Area
Regional Area
Local Area
• FPLMTS/UMTS/IMT-2000– Universal multimedia information access with mobility
spanning residences, businesses, public/pedestrian,mobile/vehicular, national, and global regions