Transcript Telecom - University of Pennsylvania

Basic Telecommunications
• Vocabulary, concepts, more “bullet
proofing”
• Touch on just a few basic points
– essentials of technology and where it’s
going
– essentials of regulation and where it’s
going
• Raise for discussion certain
management issues
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Basic Telecom Terms and Concepts, 1
• Transmission facilities
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Twisted pair
Coaxial cable
Microwave
Satellite
Fiber optics
Wireless
• Signaling
– Analog--continuous
– Digital--discrete
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Basic Telecom Terms and Concepts, 2
• Analog signaling
– AM, FM, etc.
– Limitations
» Error correction
» Encryption
• Digital signaling
– Computer friendly
– Facilitates
» Error correction
» Encryption
– Fits with fiber optic transmission facilities
– “The way the world is going”
• Modems
– “Modulator--demodulator”
– A to D and D to A
– Because the voice network is analog
» At the handset
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Basic Telecom Terms and Concepts, 3
• Switching
– The cloud
– The cloud is expensive
– Switching makes better use of the cloud
• Kinds of switching
– Circuit switching
– Message switching
– Packet switching
» And the Internet
» And ATM
– Broadcasting
– Cellular
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Basic Telecom Terms and Concepts, 4
• Voice networks
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RBOCs
Other local telcos
Long distance carriers
Cable companies?
• Data networks
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LAN
WAN
etc.
Often (usually) use voice network
transmission facilities
• Cable TV networks
– Microsoft and $1 billion/yr R&D on the set
top box
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Where Do Networks
Come From?
• Long distance carriers
– AT&T, MCI, Sprint, etc.
• “Common carriers”
• VANs
– And the Internet
• The Internet and ISPs
• Private networks
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Telecom Standards and Regulation
• Voice network regulation (U.S.A.)
– 1934-1981
– 1982-present
» RBOCs etc.--local loop provider
regulated, but less so under the
Telcom Act of 1996
» Long distance: largely unregulated
• Data communications?
– Basically, anything goes
– But whose transmission facilities are
used?
» Largely: from the voice networks
• Voice networks
– Interconnected world-wide
» Standards
» Legal requirements
• Data networks? Cable?
• Recent (de)regulatory actions
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The Internet
• The world’s first network for
making data calls
– NB telex
• History and culture
– ARPA net, nuclear attack
– NSF net and the open community
– Governance
• Design policies
– Simple protocols (e.g., TCP/IP)
– Public and open
• Continuing rapid growth
– Electronic commerce
» Consumer-oriented
» Business-to-business
– User base growing beyond “young male
nerds”
• Cost of use?
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The Last Mile Problem
• What it is
• Possible solutions
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Upgrades of existing plant
Cable
Fiber optics
Wireless
• The competitive scene TODAY
– Cable companies (and Microsoft)
– DSL and the telcos (and Microsoft)
– Other telcos
• Why is the computer industry
mucking in the last mile problem?
• Prognostications?
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The Protocols Problem(s)
• Important concept: layered
architectures for
telecommunications
– OSI reference model, 7 layers
– Also important for software in general
– Abstraction as a way of handling complexity
• Importance of standardization
– de jure
– de facto
– Internet?
• Development of standards to date
– Telephony
– Data communications
» And the Internet
• For electronic commerce?
– Incomplete
• Managerial/decision issues?
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Further Issues for
Discussion
• Outsourcing of network provision
and management
– Options
– Management issues
Imagine you are about to receive a
sales call…
• Commitment to standards
– Which ones?
– Who to believe, trust, or bet on?
• Assuming AAA networks (the
Internet on steroids),
– Productivity opportunities? (and what will it
take to realize them)
– Industrial-organizational consequences?
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This slide
unintentionally
left blank
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Computer Mediated Communication
(CMC): 1
• Telex
– A world-wide telecommunications system
– Up and running for > 100 years
– Digital signaling
• Telephone
– A world-wide telecommunications system
– Up and running for > 50 years
• Isn’t this enough?
– What’s missing?
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CMC: 2
• Telephones are everywhere.
– From an arbitrary telephone you can call
nearly any other telephone.
• Computers are .... all over.
– From an arbitrary computer, why can’t you
make a data call to nearly any other
computer?
• Data communications is inherently
easier (in many ways) than voice
communication.
– So why can’t you make those data calls?
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CMC: 3
• Increasingly, you can make those
data calls
– And there’s a lot of great stuff out there
now
• Call on special networks
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NSF Net
Compuserve
Prodigy
etc.
• And THE INTERNET...
– An internet: a network of networks
– The Internet: The Mother of All Internets
• The world we are coming to
– “Anything, anytime, anywhere...”
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