EECS 122: Introduction Communication Networks

Unit 1: The question and history of the solutions… What do use communication for ?

• Exchanging Information !!! /Getting information… - Runners (marathon!), Flags, Mirrors…. Etc.. - -mail, WWW…

• Maintaining inter-human relations - Letters (of affection!) - Phone … - SMS, CHAT, SOCIAL NETWORKS….

• Entertainment - Passive Live Theater/Circus/Movies/Radio/TV/Videos (on demand?) - Active Games!!! – network games – virtual worlds

AW: Unit 1 2 EE 122 Spring 2015 2 What to communicate: Information, data • Information - Facts, Concepts, Ideas Information - Human – oriented term Facts, concepts, • Data (encapsulated in media) ideas, … - A formalized representation of facts, concepts, ideas - Example: text, speech, picture - A human interpretation of data, conferring meaning to data

• In Engineering we are interested in Data - Capturing “information” in the form of Formalized data (recording videos, taking pictures, representation of recording voice) information - Delivering data quickly to proper persons in form of media with high fidelity and efficiency

AW: Unit 1 3 EE 122 Spring 2015 How?

• First solution: Couriers - Runners (a..a. the story of marathon). Horse courriers, e.. - The concept of Relay! • Telecommunication = moving information over long distances - Without moving a human.. - But to selected, intended partners…

• But HOW to move quicker? - Using “life help” – pigeons... - Using “guided media” to carry the document containing data è - (e.. the pneumatic post, see eg. https://about.usps.com/who-we- are/postal-history/pneumatic-tubes.pdf ) - Using SIGNALS, .e. physical phenomena able to propagate with high speed: Light, electricity, radio waves…

AW: Unit 1 4History of TelecommunicationEE 122 Spring 2015 4 AW: Unit 1 5 EE 122 Spring 2015 The early optical signals

• Visual signals - Limited to the Line of sight (LOS) • Examples: - Mirrors, Smoke - Humans giving signs... signaling convention: seamen flags,

Hissed flags http://www.christinedemerchant.com/flag- .html

n Flag , e.g. http://www.anbg.gov.au/flags/semaphore.html

n The • And, much , much later: the transmission ☺

AW: Unit 1 6 EE 122 Spring 2015 Optical Telegraph

• Optical Telegraph (Chappe, 1793) - Need for fast information flow in time of French Revolution

n installed the first optical telegraph line in summer 1794

AW: Unit 1 7 EE 122 Spring 2015 7 Electricity made THE change…

• Telegraph (Morse, 1837) - Digitally coded text information, hard copy option (see e.g http://morsecode.scphillips.com/morse2.html ) - Large distance covered with constant quality - Low speed, rather public than individual use • Telephone (Bell, 1876, many claims from others…) - Transmission of voice (analog information) - Analog (later digital! Information transmission) - Individual use, end-system (not person) addressed - Data transmission by telephone is possible - World’ largest unified technical system! • Broadcast Services (30ties in 20th Century) - Radio, TV

AW: Unit 1 8 EE 122 Spring 2015 8 Telegraph (1) [Noll, op. cit)]

• Diagram of Simplex Electromagnetic Telegraph

n a) Single simplex link

n ) Two simplex links cascaded by repeater

AW: Unit 1 9 EE 122 Spring 2015 9 Telegraph (2) [Noll, op. cit)] • Simplified diagram of Morse's half-duplex telegraph

AW: Unit 1 10 EE 122 Spring 2015 10 Telephones - The basic Idea (1) [Noll, op. cit)]

Variable-resistance transmitter

Bell's liquid transmitter

AW: Unit 1 11 EE 122 Spring 2015 11 Telephones - The basic Idea (2) [Noll, op. cit)]

Watson's electromagnetic receiver

AW: Unit 1 12 EE 122 Spring 2015 12 Early Broadcasting…

• Drummers, walking and announcing (acoustic)

• Mr. Litfaß – 5. Dec. 1854 Berlin, Germany (visual!)

• Much later: Megaphones…

(Acoustic, now: rlectric amplification of the acoustic signal!)

AW: Unit 1 13 EE 122 Spring 2015 13 Some fundamentals… before moving further

• Non-Zero delay between sending and receiving of a given message… (propagation delay!) - The speed of light – the highest possible is c =300 000 km/s in vacuum!! - The speed of electricity and light in optical fiber is = 2/3 c • A bounded amount of messages can be posted in a time unit... - Think in term of the speed of Morse´ing or typing… or… - Think in terms of the speed of your access…☺ • Loss/errors in data transmission

è THIS ALL IS REALITY !!!

AW: Unit 1 14 EE 122 Spring 2015 Realistic Transmission…

• Propagation delay : - Propagation speed v: - d = distance / v

• Data rate : How much SOT:Start of messages/sec or bits/second transmission can a sender transmit? - (EOT – SOT) = Data size / data rate EOT: End of Time • Error rate: What is the rate of transmission incorrect messages arriving at the receiver? Delay d - Corrupted messages are frequently deleted……

Distance

AW: Unit 1 15 EE 122 Spring 2015 Transmission medium can store data • What happens during a transmission? Start of transmission - Bits propagate to the receiver - Sender keeps sending bits

- First bit arrives after d seconds Delay d Time - In this time, sender has transmitted d*r bits - They are “stored in the wire” (or in the Air!) • d*r is the product of delay and data rate - Commonly called Example (transcontinental): -delay product • Data rate 100 Mbit/s - Crucial network property • Delay 4000km/(2/3c) = 0.02 s

• d*r = 2 Mbit (in the wire) AW: Unit 1 16 EE 122 Spring 2015 Challenges in using signals

• The speed of the signal can hardly be influenced…# • The number of data block (groups of bits)/second which we can transmit, as well as the probability of them being in error can be influenced - This is issues of communications… (eg. EE121) - We will discuss these topics shortly to understand how we can use it …or suffer form them…

AW: Unit 1 17 EE 122 Spring 2015 Just a line? [.Karl, Paderborn]

• Connecting many phones - the simple issue ?

AW: Unit 1 18History of TelecommunicationEE 122 Spring 2015 18 Concepts: The Network, Switching

• Choosing the recipient of your call… • It is NOT efficient to build a physically separate path for each pair of communicating end systems (left picture). • CONCEPT: The Network: There is a set of path sections (e.g. electrical cables) and switching points (right picture). • “End systems” vs.“switching elements” a.k.a routers/bridges NOTE THE SIMILARITY TO OTHER NETWORKS ….

AW: Unit 1 19History of TelecommunicationEE 122 Spring 2015 19 Communication Networks…a lot of questions • How to move data to a desired destination ? - Path selection? • How to structure data? “Portions”? Flows? • Mixing streams of data in the switches …overload? Losses…variable delay? • Binding of communication in the end systems?

Many, Many issues…. This is the main subject of THIS CLASS

AW: Unit 1 20 EE 122 Spring 2015 Concepts: Names, Addresses, Routing…

• Name: WHO (identifies the object) - Structured for simple reference by humans! - E.g. According to organizational structure? Mnemonics? • Address: WHERE TO FIND (the object) - Must be REACHABLE - The object can move (mobility) è change address … • Route: HOW TO GET THERE - Has to assure delivery. - It is nice, if the address structure helps.. (e.g. street blocks)

? How to find the Address of some object ? ? How to find the route ?

AW: Unit 1 21 EE 122 Spring 2015 Some considerations

• Which objects would one like to address - Humans? Devices? Processes? • An object might have many points of access - A building with entrance from 2 different streets? - A human has Phone, e-mail, post, … - A laptop with WLAN (university Network) and ATT cellular? • How can addresses be grouped to enhance routing ? - City – District - Street- house – apartment

AW: Unit 1 22 EE 122 Spring 2015 Types of addresses

• Unicast: A single destination • Multicast: Destination is a group (defined explicitly or implicitly – i.e. every entity knows if it belongs…) • Anycast: Whoever of the group members • Broadcast: everybody…

AW: Unit 1 23 EE 122 Spring 2015 Computer Networks

• User logged into a single computer (or a process started by this user!) can: - Access any of the machines and use its resources - Execute processes. - Cause moving data (e.g. files) • Some important gains - Resource utilization: processor cycles, printers, specialized programs. - The centralized management of programs and data (software versions, backups) - Increase of SYSTEM reliability (as whole!) • Sharing and exchanging DATA - collaborative activities (work, entertainment, …)

AW: Unit 1 24History of TelecommunicationEE 122 Spring 2015 24 Computer Networks: Consecutive challenges • Challenge I: Interconnection of different computer/ types • Challenge II: Transmission Speed/Transmission Distance/… - WAN -

n limit in distance

n Provides national and international connectivity - LAN -

n Less than approx. 1 km in distance

n Provides local connectivity typically within a building - And many more….

n Mobile Cellular Data Networks

n BAN (Body Area Networks)

n SAN (Storage Area Networks)

n Desktop Area Networks…

n Industrial Networks

AW: Unit 1 25History of TelecommunicationEE 122 Spring 2015 25 Internet: Interoperability vs. Heterogeneity

WAN

MAN LAN

Gateway

See:The Brief

AW: Unit 1 26History of TelecommunicationEE 122 Spring 2015 26 Recent tendencies • Challenge III: Multimedia Communication - Observation: The information is stored/exchanged in MEDIA

n Voice, Video, Data…

n Different requirements as for transmission!!! - Historically supported by different technologies (telephony, Radio/TV - Convergence….

• Challenge IV: Mobility (cordless?, nomadic?, mobile?) - Cordless Telephone, cellular telephony, cellular data - LANs etc… - Convergence of the devices: Smart Phones….

AW: Unit 1 27History of TelecommunicationEE 122 Spring 2015 27 Internet host count

See: https://www.isc.org/solutions/survey

https://www.isc.org/services/survey/

AW: Unit 1 28History of TelecommunicationEE 122 Spring 2015 28 What is the value of a network ? • Communications networks increase in value as they add members--but by how much? - How useful is a single phone using a unique new technology? Two phones? 20 Phones? 1 billion of phones…. - Btw. as by October 2012 they are around 4.2 billion mobile communication users (and 6.3 billion subscriptions!) out of worlds population of over 7 billions of people!

• The Metcalfe´s Law „The value of a communication network is proportional to the square of the user number!

• The n log(n) Law See: Bob Briscoe, Andrew Odlyzko, Benjamin Tilly IEEE Spectrum July 2006, pp. 32- 39

AW: Unit 1 29 EE 122 Spring 2015 National Broadband Plan – spring 2010

• Goal No. 1: At least 100 million .S. homes should have affordable access to actual download speeds of at least 100 megabits per second and actual upload speeds of at least 50 megabits per second. • Goal No. 2: The United States should lead the world in mobile innovation, with the fastest and most extensive wireless networks of any nation. • Goal No. 3: Every American should have affordable access to robust broadband service, and the means and skills to subscribe if they choose. - 90% broadband adoption rate by 2020. • Goal No. 4: Every community should have affordable access to at least 1 gigabit per second broadband service to anchor institutions such as schools, hospitals, and government buildings. • Goal No. 5: To ensure the safety of American communities, every first responder should have access to a nationwide, wireless, interoperable broadband public safety network. • Goal No. 6: To ensure that America leads in the clean energy economy, every American should be able to use broadband to track and manage their real-time energy consumption. National broadband plan http://www.broadband.gov/download-plan/

AW: Unit 1 30History of TelecommunicationEE 122 Spring 2015 30 From desktop to … [Wawrzynek, BWRC]

AW: Unit 1 31 EE 122 Spring 2015 31 The Push: STAY CONNECTED!!! è An average smartphone will generate 1.3 GB of traffic per month in 2015, a 16-fold increase over the 2010 average of 79 MB per month. [Cisco,VNI MOBILE, 2011]

• 2010 – Tablet is the device of the year…. è Tablets: Primary intent – wireless operation.

• A Plethora of Apps for smart phones/tablets supporting you „on the way“ - Keep all your information „in the cloud“!

• Networks start being bottlenecks… - . Wortham, “Customers Angered as iPhones Overload AT&T”. http://www.nytimes.com/2009/09/03/technology/companies/03att, Sept 09 - Mobile traffic expected to grow 20-30 times within 5 years!

AW: Unit 1 32History of TelecommunicationEE 122 Spring 2015 32 Mobile Data Growth [Cisco VNI Mobile, 2011]

Mobile traffic grew 2.6x in 2010 (nearly tripling for 3rd year)

AW: Unit 1 33History of TelecommunicationEE 122 Spring 2015 33 Deeply embedded systems…

• The devices DO shrink... Really ... - When the idea of „smart dust“ (Pister et al., UCB) has been presented, it sounded like utopia... • Now: Potential users are really considering putting the Intelligent Sensors in „strange“ places - Smart phones: (Accelerometer, mic, camera) + signal processing - Watches, necklaces, ear-rings, tires, glasses, pens… - Inside machines... (own experience!) - Under your skin... (Univ Utah; Fraunhofer IZM/TUB) • How to use such „information quanta“ ? - It is to „fine grained“ to trigger some actions by itself - It is to valuable to be used only for one purpose. Challenge: Combining information for useful usage!

AW: Unit 1 34History of TelecommunicationEE 122 Spring 2015 34 Infrastructure monitoring…

net

Source: Sukun Kim, UCB

AW: Unit 1 35History of TelecommunicationEE 122 Spring 2015 35 Smart House…Smart Home…

• Advanced user interfaces • Sense of presence and

AW: Unit 1 36History of TelecommunicationEE 122 Spring 2015 36 The “Ambient Intelligent” Home …

A Multimedia environment adapting to the activities and mood of the user…. Support for virtual reality and immersive Tele-conferencing…. Courtesy Fred Boekhorst, Philips

AW: Unit 1 37History of TelecommunicationEE 122 Spring 2015 37 The Movie…

• http://www.youtube.com/watch?v=sfEbMV295Kk

• Cyber-physical Systems generate a different traffic… - Many orders of magnitude bigger population of network components - Devices (Sensors!) have very limited energy sources - should be mostly switched off – only occasionally send data

n Special rules for accessing the network (compare phone dialing!)

n Sending short data blocks per session – rather than long streams of long data blocks…. - But: think of virtual reality? Of life interaction with the remote reality (examples. examples..)

AW: Unit 1 38History of TelecommunicationEE 122 Spring 2015 38 The Data Tsunami … [. Enescu,CISCoO

• In 2000 years of recorded history humans created 2 Exa-bytes of data. • We generate over 2.5 Exa-bytes of data/ day now ! • Yes, the data are coming in HUGE amounts from devices… - Energy utility companies process 1.1 BILLION data points (.5TB) per day - A large offshore oil field produces 0.75TB of data weekly - A large refinery generates 1TB of raw data per day - An airplane will generate 10TB of data for every 30 minutes of flight • More and more “cyber- Physical” system usage Sensors è Data è Action

AW: Unit 1 39 EE 122 Spring 2015 The Swarm at The Edge of the Cloud

Infrastructural core

[J. Rabaey, ASPDAC’08]

AW: Unit 1 40 EE 122 Spring 2015 The joint optimization

The space

data storage – computation- communication

has to be considered in a wholistic way!

AW: Unit 1 41 EE 122 Spring 2015