What is it?

• Those thin, copper strands that connect things to telephone (or electrical) network.

Some Benefits

• Easier to repair than Fiber- simply splice.
• Easier to switch- use traditional on/off switches

Some Problems

• Expensive, conducting metal; very limited capacity
• 'The Final Mile' or 'The Final Loop.' Already in Use- Who would pay to replace with a newer transmission system like Fiber Optics?-

Developments

• Digital Burst to send video signals short distance into home (cf. "Final Mile"

What is it?

• Thicker, shielded copper cable capable of carrying video signals
• The Cable "broadcasting" Set-up: (1) Program Sources [like Satellite Reception, Recorded Material, Traditional B'cast] go from (2) Head End to (3) Amplifiers to (4) Local Drop at home.
• Analog switching, primarily- Digital transmission and compression still experimental.

Some Benefits

• Like "Twisted Pair" easier to repair and splice than fiber optic
• If all consumers want is some video reception, currently cost effective
• If local provider, then they can include local content (can contrast with satellite)

Some Problems

• Limited Capacity?- Is even 500 channels enough in Age of Internet?
• 'Down Stream Bias'- 'Switches' designed to feed content downstream; limited 'upstream' interactivity (mostly program selection). Hence is not a major Telephone/Internet carrier competitor yet.

Developments

• 'Cable modem'? Plans and experiments to develop and expand 'upstream capability' to expand interactive market. Still experimental.

What is it?

• Micro-Lasers transmit coherent light down glass strand size of hair

Some Benefits

• Relatively inexpensive material; vast carrying capacity; lay down like copper

Some Problems

• Can break when bent; sometimes need amplifiers for long distance
• Need to develop new skills/tools to diagnose and fix

Developments

• More frequencies through light cable
• Need to develop optical switches for full efficiency

What is it?

• Digital Broadcast- Broadcast signal is digitally encoded/ decoded
• Spread Band, Packet Broadcast- Broadcast not on one assigned frequency, but on a range of free, available frequencies (just as packet switching looks for a free line to use)

Some Benefits

• Get Closer to the edge of the assigned transmission frequency than analog transmission can
• Increase in fidelity, transmission efficiency
• Many new 'smart' technologies need digital

Some Problems

• Needs new generation of transmitters and receivers- what happens to old devices?
• New transmitters/receivers- more expensive?
• Needs new generation of regulation- how use spectrum; who gets new frequencies?

Developments

• Part of ongoing merge of broadcast with new digital communication media
• New: cellular telephone; portable digital devices like hand held computers

Basic Terms

• "Transponders"- they resend message back to earth from satellite;
• "Geo-synchronous orbit"- stable orbit above the earth.
• "Footprint"- Who can pick up satellite signal?

Some Benefits

• Remote Reach- Able to reach remote sites without cost of physical wiring; able to bypass terrestrial blockages
• Broad Reach- Able to reach larger audiences

Some Problems

• Cost: Building, Delivering, Maintaining Satellite, Providing all earth uplinks and downlinks
• Limited number of geosynchronous orbits- who gets access to them?

Developments

• Satellites at less than geo-synchronous orbits - use a fleet of sub geo-synchronous satellites to bypass terrestrial telephone networks?