Bandwidth Wired and Wireless Technology
Visual Imaging in the Electronic AgeProf. Donald P. Greenberg
October 31, 2019Lecture #18
Networks Origin and History
History Of The Internet ARPA Team
Internet - History & Growth Chronology
1973 - Vinton Cerf & Robert Kahn - designed Internet architecture based on TCP/IP
1979 - Configuration Control Board - contracted parts of infrastructure
1980 - U.S. Department of Defense - adopted TCP/IP, MILNET designed to withstand atomic attack - becomes ARPANET
Early 1980’s - ARPANET becomes known as Internetresearchers enticed to use CSNet (paid by NSF)
Internet Protocols• Communication Protocols (TCP/IP) – used to link computers and other
communicating devices together
• Computer Languages (HTML) – used to encode the format of web pages
• Communication Protocols (HTTP) – used to retrieve web pages from elsewhere on the network
• Protocols of the World Wide Web (www)
• Graphically oriented Web browsers (Mosaic)
All of this is FREE!
Internet - History & Growth Chronology cont’d1983 - TCP/IP - becomes standard
1990 - ARPANET - decommissioned and replaced by NSFNet backbone NSF -expands network to other research communities
1993 - NSF -no longer provides funding for NSFNet backboneNAP’s (network access points) established in four cities
Circa 1993
North American City to City Connections
http://chrisharrison.net/projects/InternetMap/, September 2010
Internet - History & Growth Chronology cont’d1993 - Mosaic - Introduced by University of Illinois (Marc Andreesen)
1994 - NSF -links four national supercomputer centers at 155 Mbs(bandwidth to approach 2.5 Gbs) contracts MCI to link other sites
Internet - opens to commercial usage
1994 - Netscape - formed by Jim Clark
Level 3 Map 2012
Uncle Sam, Ma Bell And Her Babies: A Timeline
1982 AT & T and the Department of Justice signed consent decree.
• AT & T divests its 22 local Telco’s
• AT & T can enter previously restricted arenas
• Baby Bell’s prohibited from manufacturing equipment and offering long distance services. They cannot provide content
Uncle Sam, Ma Bell And Her Babies: A Timeline
1984 The AT & T divestiture takes effect.
1987 The F.C.C. scraps rules that limit phone company profits.
1988 Judge Greene agrees to let the Bells offer voice mail and E-mail services, and transmit electronic publishing for others, but not provide content.
Con’t: Uncle Sam, Ma Bell And Her Babies: A Timeline
1989 A seven-year ban on AT & T’s entry into electronic publishing is allowed to lapse.
1991 Judge Greene removes the information services restriction from the Bells, but leaves in place the rules against manufacturing and long-distance service.
1993 A Federal court in Virginia lifts for Bell Atlantic the video programming ban contained in the Cable Television Act of 1984.
Con’t: Uncle Sam, Ma Bell And Her Babies: A Timeline
1994 The House overwhelmingly approves legislation's that would let the Bells make equipment and enter the cable and long-distance business in return for accepting competition in their local telephone markets.• A comparable Senate bill collapses - too much competition for the cable and long-distance companies.
1995 The Senate passes a bill to overhaul communications regulation. • The House passes a communications bill that is similar to the Senate
version.1996 New Telecommunication bill passed February 1, 1996
Wired vs. WirelessThe Physics of Sound & Light
Wired Technology
Sound (air) 1100 ft/second
335 meters/second
Light (vacuum) 186,000 miles/second
300 x 106 meters/second
Light (fiber) 200 x 106 meters/second
Electricity (copper)225 x 106 meters/second
Physics 101 Speed (velocity) Of Sound & Light
Physics 101• Relationship between distance, velocity and time
• Distance = velocity x time
• d = distance
• v = velocity
• t = time
vd td/t, vvt,d ===
Physics 101
• Relationship between velocity, wavelength and frequency
• Velocity (v) = frequency (f) x wavelength ( λ)
fvvffλv === λ
λ , ,
Cycleor
wavelength
amplitude
time
Metersftftcycles
ft
Metersftcycles
ft
01.0301
33011
sec/33000sec/1100
ondcycles/sec 33000 Frequency
1.13
11sec/300
sec/1100ondcycles/sec 300 Frequency
ond1100ft/sec air in sound ofVelocity
3300
300
≈===
=
===
==
λ
λ
Physics 101
Lightning
Light vs Sound
• Human ear•Hears between 300-33,000 cycles/sec.
• Human eye•Sees at wavelengths between 400nm-700nm (blue to red)
Comparison Between Wavelengths Of Sound And Light
Short Wavelengths
Sound 0.01 M
Light 400nm
Ratio xs 000,570,1107001.1
9 =×= −
λλxs 000,25
1040001.0
9 =×= −
λλ
Long Wavelengths
1.1 M
700nm
Speed of light = 300 x 106 meters/second
Speed of sound = 335 meters/second
Ratio of frequencies
Bandwidth Of Light & Sound For A Single Channel
s
ss λ
vf, λvf ==
λλ
λ
λ s
s
s
ss vv
v
v
ff
×==
66
10400,2200025335
10300×=×
×= ,
soundof Bandwidthlight of Bandwidth
For a single channel (one bit/cycle)
Switches & Routers
Telephone Switches
Telephone Switched Networks
Routers
• Routers enable data communication between computers on any network or the Internet
• They “route” data packets to their destination and operate on level three of the seven layer internet protocols
• Complex distribution routers (dynamic routers) can evaluate the best data paths based on distance, congestion, etc. They can also integrate security firewalls or services like IP voice or video
Transmission BandwidthThe carrying capacity of the system measured in units per second (e.g. Kbs, KBs, Mbs, MBs, Gbs, GBs)
LatencyThe pause time with zero movement of information(e.g. time to get started, initialize system, find data, etc.)
Network Bandwidth & Latency
CPU Bandwidth & LatencyProcessing BandwidthComputational capacity measured in instructions per second (e.g., MIPS, FLOPs, GIPs)
Memory LatencyTime to seek and retrieve data from memory so that processing functions can be executed
Multi-level caches reduce the latency
Path From Stanford to MIT
• The distance from Stanford to Boston is 4320 km
• The speed of light in a vacuum is 300 x 106 meters/sec.
• The speed of light in fiber is roughly 66% of the speed of light in vacuum
• The speed of light in fiber is 200 x 106 meters/sec.
• The one-way delay to Boston is 4320 km/200 x 106 meters/sec. = 21.6 milliseconds
• The round-trip time to Boston and back is 43.2 milliseconds
• The current ping time (1996) from Stanford to Boston over the Internet is about 85 milliseconds.
Ping Time From Stanford To MIT 1996
Hop Min Avg Max Name1 3/3 0.003 0.003 0.004 jenkins-gateway.stanford.edu2 3/3 0.003 0.006 0.013 core-gateway.stanford.edu3 3/3 0.004 0.004 0.004 sunet-gateway.stanford.edu4 3/3 0.003 0.003 0.004 su-pr1.bbnplanet.net5 3/3 0.004 0.004 0.005 paloalto-br1.bbnplanet.net6 3/3 0.006 0.006 0.007 oakland-br1.bbnplanet.net7 3/3 0.036 0.036 0.037 denver-br1.bbnplanet.net 8 3/3 0.036 0.160 0.406 denver-br2.bbnplanet.net9 3/3 0.056 0.058 0.059 chicago1-br1.bbnplanet.net
10 3/3 0.056 0.058 0.059 chicago1-br2.bbnplanet.net11 3/3 0.076 0.077 0.078 boston1-br1.bbnplanet.net12 3/3 0.076 0.076 0.076 boston1-br2.bbnplanet.net13 3/3 0.077 0.077 0.078 cambridge1-br2.bbnplanet.net14 3/3 0.080 0.081 0.083 cambridge1-cr1.bbnplanet.net15 3/3 0.080 0.145 0.212 cambridge2-cr2.bbnplanet.net16 3/3 0.079 0.081 0.084 ihtfp.mit.edu17 3/3 0.083 0.096 0.104 b24-rtr-fddi.mit.edu18 3/3 0.082 0.082 0.084 radole.lcs.mit.edu19 3/3 0.082 0.085 0.089 mintaka.lcs.mit.edu
Name: Stuart Cheshire Modem: no modem (Quadra 700 built-in Ethernet)ISP: BBN (Bolt, Beranek and Newman)
Cornell to Stanford, 11/4/2016
Traceroute Demo Traceroute is a command which can show you the path a packet of information takes from your computer to one you specify. It will list all the routers it passes through until it reaches its destination, or fails to and is discarded. In addition to this, it will tell you how long each 'hop' from router to router takes.
In Windows, select Start > Programs > Accessories > Command Prompt. This will give you a window.
Enter the word tracert, followed by a space, then the domain name. (example: tracertstanford.edu)
Wireless Coding Technologies
Multiple Channels
First Generation (Analog)
Early 1980’s - 2000
AMPS (Advanced Mobile Phone System)
FDMA (Frequency Division Multiple Access)
Scientific American Oct. 2000
First Generation FDMA
Scientific American Oct. 2000
Scientific American Oct. 2000
First Generation FDMA
Second Generation (Digital) TDMA
Early 1990’s - 2000
TDMA (Time Division Multiple Access)
Original GSM (Global System for Mobile Communication)
Second Generation (Digital) TDMA
Scientific American Oct. 2000
Second Generation (Digital)Early 1990’s - 2000
TDMA (Time Division Multiple Access)
Original GSM (Global System for Mobile Communication)
CDMA (Code Division Multiple Access)
PCS (Personal Communications Service)
Third Generation CDMA
Scientific American Oct. 2000
The Negroponte Switch
1990’s → Voice communication sent through wiresVideo programs sent through air
2010 → Voice communication sent through airVideo programs sent through cable
Gilder Report
Fourth Generation W-CDMA• 4G mobile technology is approximately 10x 3G
• Defined goals includes enhanced security measures, and smoother transition of data when a device moves across areas covered by different networks.
• Also includes IP telephony, ultra-broadband internet access, gaming services, and Internet TV, at least 100Mbs when client is moving at high speeds, 1 Gbs when client is stationary.
W-CDMA Analogy
5 G Systems LTE
• Two competing systems, WiMax (Clearview and Sprint Nextel) and Long Term Evolution (LTE) backed by Verizon, AT&T, and Qualcomm
• Target peak data rates– 100 Mbits/second for high mobility– 1 Gbit/second for low mobility
Fifth Generation Networks (5G) • 5G is still relatively new and has been implemented in
only a few countries
• First substantial deployments were in April 2019 in South Korea.
• Currently six companies sell 5G systems (Huawei, Samsung, ZTE, Nokia, Datang Telecom, and Ericsson
2018-2030
Sixth Generation Networks (6G) 2030
Supply vs. Demand
• The wireless bandwidth (supply) is increasing at exponential growth rates.
• The Internet demand for bandwidth is also increasing at exponential growth rates.
• Which exponent is greater?
Everywhere
Anyone
Mark Alpert, George Musser. “The Wireless Web: Special Report/Introduction,” Scientific American, October 2000, v. 283, issue 4, p. 38..
To Anywhere
Global Consumer Internet Traffic
Global Consumer Internet Traffic
Data explosion vs. bandwidth
• Which will grow faster?
• The problem is that bandwidth is limited!
Mapping the Frequency Spectrum
Samsung QLED 8K Display 2019
32 MegaPixels
Volumetric Medical Data
Static Information
• HDTV– 1920 x 1080 x 3 bytes ≈ 6 Megabytes/Image
• Cell Phone photography – 12 Megapixels x 3 bytes per pixel = 36 Megabytes
• Series of MRI slices - volume image e.g. digital human
– 1024 x 1024 x 1 byte x 200 slices = 200 Megabytes
Dynamic Information
• Voice: 44,000 bits/second
• HDTV: 1920 x 1080 x 3 bytes x 120fps =
712 Mbytes/sec.
• Dynamic volume Image
e.g. Beating heart
512 x 512 x 200 slices x 30fps = 1.57 Gbytes/second
Cardiac MRI
Current Trends
• Everybody’s cell phone (Phone/Camera are combined)
• Selfie’s
• Internet of Things
• Children (Adults) playing games
• Migration from Cable TV to Internet TV
Current Trends
• Everybody’s cell phone (Phone/Camera are combined)
• Selfie’s
• Internet of Things
• Children (Adults) playing games
• Migration from Cable TV to Internet TV
• Students looking at emails or playing games while grandpa is lecturing!
Future Trends
• Volumetric Data
• Light Fields
• VR/AR & Entertainment
• Cloud Storage
• Autonomous Driving Vehicles
Local Wireless Technologies
Bluetooth
• More than just cable replacement
• Scans the area for other Bluetooth devices
• Can perform background operations
(e.g., identification, security, checking e-mail, stock prices, etc.)
BluetoothInitial Specifications
Originally conformed to standards 802.11a & 802.11b. A 10-meter radio signal (through walls)bandwidth of close to megabit/second
Cost to manufacture was estimated at $5/chip with mass production in 2008. Now it is much, much cheaper.
Later versions have longer distances (20+ meters) and higher bandwidth
Table page 26, IEEE Spectrum, Sept. 2003
Happy Halloween!!!
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