Networks Illustrated: Principles without Calculus

About this course: What makes WiFi faster at home than at a coffee shop? How does Google order its search results from the trillions of webpages on the Internet? Why does Verizon charge $15 for every GB of data we use? Is it really true that we are connected in six social steps or less? These are just a few of the many intriguing questions we can ask about the social and technical networks that form integral parts of our daily lives. This course is about exploring the answers, using a language that anyone can understand. We will focus on fundamental principles like “sharing is hard”, “crowds are wise”, and “network of networks” that have guided the design and sustainability of today’s networks, and summarize the theories behind everything from the social connections we make on platforms like Facebook to the technology upon which these websites run. Unlike other networking courses, the mathematics included here are no more complicated than adding and multiplying numbers. While mathematical details are necessary to fully specify the algorithms and systems we investigate, they are not required to understand the main ideas. We use illustrations, analogies, and anecdotes about networks as pedagogical tools in lieu of detailed equations. Please note that per Princeton University policy, no certificates, credentials or reports are awarded in connection with this course.

Created by:  Princeton University

• Taught by:  Christopher Brinton, Visiting Researcher and Lecturer

  Department of Electrical Engineering

• Taught by:  Mung Chiang, Professor

  Electrical Engineering

Level Beginner Language English How To Pass Pass all graded assignments to complete the course. User Ratings 4.4 stars Average User Rating 4.4See what learners said Coursework

Each course is like an interactive textbook, featuring pre-recorded videos, quizzes and projects.

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Syllabus


WEEK 1


Introduction
An introduction to what this course is about: the fundamentals behind social and technical networks.


5 videos, 3 readings expand

1. Reading: About Us
2. Reading: Suggested Readings and Links
3. Reading: Correction to Course Info
4. Video: Networking Principles Without "Calculus"
5. Video: Sharing Is Hard & Ranking is Hard
6. Video: Crowds Are Wise & Crowds Are Not So Wise
7. Video: Network Is Expensive & Divide and Conquer
8. Video: End to End & Bigger And Bigger

Power Control in Cellular Networks



How is it possible that we can all communicate effectively without disrupting each other's calls, messages, or Internet usage? In this lesson, we will take a look at some of the methods that have been developed for letting us "share" the air over which our phones communicate.


21 videos, 1 reading expand

1. Reading: Power of Networks
2. Video: Mobile Penetration
3. Video: Multiple Access
4. Video: FDMA
5. Video: 0G
6. Video: Attenuation
7. Video: Cells & 1G
8. Video: 2G
9. Video: TDMA
10. Video: CDMA
11. Video: Cocktail Party Analogy
12. Video: Near-far Problem
13. Video: SIR
14. Video: DPC
15. Video: DPC Computation: Part A
16. Video: Negative Feedback
17. Video: DPC Computation: Part B
18. Video: Convergence
19. Video: Distributed Computation
20. Video: Handoffs
21. Video: CDMA & 3G
22. Video: Summary

Graded: Problem Set #1

WEEK 2


Random Access in Wifi Networks
In this lesson, we will investigate WiFi, another type of wireless network. Rather than having stringent power control algorithms as we saw for cellular, WiFi relies on "random access" methods to manage interference among users in the same location.


15 videos, 1 reading expand

1. Reading: Power of Networks
2. Video: Unlicensed Spectrum
3. Video: Traffic Analogy
4. Video: WiFi Standards
5. Video: WiFi Deployment
6. Video: Accessing WiFi
7. Video: Interference
8. Video: Controlled vs. Random Access
9. Video: Random Access Protocols & ALOHA
10. Video: ALOHA Successful Transmission
11. Video: ALOHA Throughput
12. Video: ALOHA Inscalability
13. Video: CSMA Carrier Sensing
14. Video: CSMA Backoff
15. Video: CSMA vs. ALOHA
16. Video: Summary

PageRank by Google
In this lesson, we will take a look at PageRank, Google's famous algorithm for ordering the results on its search page. PageRank is a prime example of how coming up with the right "ranking" of a set of items is a difficult yet important question in networking.


11 videos, 1 reading expand

1. Reading: Power of Networks
2. Video: New Word in the Dictionary
3. Video: Search Engines
4. Video: Webgraphs
5. Video: In-degree
6. Video: The "Random Surfer"
7. Video: Importance Equations
8. Video: PageRank Example Calculation
9. Video: PageRank Example Summary
10. Video: Dangling Nodes & Disconnected Graph
11. Video: Robust Ranking
12. Video: Summary

Graded: Problem Set #2

WEEK 3


Product Rating on Amazon



The decision of whether or not to purchase something online is often driven by the ratings that previous customers have left for it. In this lesson, we will take a look at Amazon's review system, and the see how "crowds are wise" is another important networking principle.


11 videos, 1 reading expand

1. Reading: Power of Networks
2. Video: Amazon & eCommerce
3. Video: Average Ratings
4. Video: The Wisdom of Crowds
5. Video: Rating Aggregation Challenges
6. Video: Naive Averaging
7. Video: Bayesian Ranking: Part I
8. Video: Bayesian Ranking: Part II
9. Video: Bayesian Ranking in Practice
10. Video: What does Amazon do? Part I
11. Video: What does Amazon do? Part II
12. Video: Summary

Movie Recommendation on Netflix



One of the perks of having a Netflix subscription is getting recommendations of movies to watch. Behind the scenes, Netflix uses powerful algorithms to determine which will be suggested to each person specifically. In this lesson, we will take a look at the main ideas behind these algorithms.


17 videos, 1 reading expand

1. Reading: Power of Networks
2. Video: Netflix Timeline
3. Video: Video Streaming
4. Video: Recommendation is Everywhere
5. Video: Netflix Recommendation System
6. Video: Netflix Prize: Logistics
7. Video: Netflix Prize: The Competition
8. Video: Our Example
9. Video: Raw Average
10. Video: User-movie Interactions
11. Video: Baseline Predictor
12. Video: Similarity
13. Video: Cosine Similarity
14. Video: Similarity Values
15. Video: Leveraging Similarity
16. Video: Neighborhood Predictor
17. Video: Performance of Different Methods
18. Video: Summary

Graded: Problem Set #3

WEEK 4


Midterm

Graded: Midterm

WEEK 5


Viral Videos on YouTube



What does it take for a video to become "viral" on YouTube? In this lesson, we will take a look at some of the key factors and models that have been used to explain this phenomenon. At the core is the notion of information cascade in a network, which is the counterpart to the wisdom of crowds.


12 videos, 1 reading expand

1. Reading: Power of Networks
2. Video: YouTube timeline
3. Video: Viral style and video recommendation
4. Video: Defining "viral"
5. Video: Popularity
6. Video: Information cascade & sequential decision making
7. Video: Number-Guessing Thought-Experiment
8. Video: First, second, and third "guessers"
9. Video: Analyzing cascades: Part I
10. Video: Analyzing Cascades: Part II
11. Video: Emperor's New Clothes
12. Video: Considerations
13. Video: Summary

Influencing People in Social Networks
In this lesson, we will continue with our theme of influence, now paying more attention to people's social networks. We will discuss different ways of measuring importance and a popular model for influence spread in social networks like Facebook and Twitter.


13 videos, 1 reading expand

1. Reading: Power of Networks
2. Video: Facebook & Twitter
3. Video: Who is "important?"
4. Video: Social graph
5. Video: Degree centrality
6. Video: Closeness centrality: Part I
7. Video: Closeness centrality: Part II
8. Video: Betweenness centrality: Part I
9. Video: Betweenness centrality: Part II
10. Video: Contagion: Part I
11. Video: Contagion: Part II
12. Video: Cluster density
13. Video: Marketing strategies
14. Video: Summary

Graded: Problem Set #4

WEEK 6


Pricing Data



Data makes up a significant part of our cell phone bills. How do cellular providers set these price points? In this lesson, we will see how so-called usage-based pricing schemes can send better signals than flat- rate, “buffet” schemes, leading to better sharing of the network.


11 videos, 1 reading expand

1. Reading: Power of Networks
2. Video: Our mobile data plans
3. Video: Demand for data
4. Video: Jobs' Inequality of Capacity
5. Video: Usage-based plans
6. Video: Comparing pricing schemes
7. Video: Utility
8. Video: Demand
9. Video: Demand curve & net utility
10. Video: The Tragedy of the Commons
11. Video: Flat rate creates waste & favors heavy users
12. Video: Summary

Routing Traffic through the Internet



It is hard to overstate the impact that the Internet has had on society. In this lesson, we will overview the fundamental concepts behind the way the Internet is designed. We will also take a look at routing, which is the process of determining how packets of information are transported.


22 videos, 1 reading expand

1. Reading: Power of Networks
2. Video: Sharing revisited
3. Video: ARPANET
4. Video: NSFNET
5. Video: The "Internet"
6. Video: Circuit Switching vs. Packet Switching
7. Video: Statistical Multiplexing & Resource Pooling
8. Video: Packet vs. Circuit Switching Summary
9. Video: Distributed Hierarchy
10. Video: Routing Traffic
11. Video: IP Address
12. Video: Prefix & Host Identifier
13. Video: DHCP & NAT
14. Video: Routing Protocols
15. Video: Forwarding
16. Video: Shortest Path Problem
17. Video: Bellman-Ford Example
18. Video: Cost Updates
19. Video: Example: Two Hops
20. Video: Example: Three Hops
21. Video: Example: Summary
22. Video: RIP and Message Passing
23. Video: Summary

Graded: Problem Set #5

WEEK 7


Controlling Congestion in the Internet



The Internet has many important tasks to manage, like routing packets (discussed in the last module) and controlling congestion. This workload is modularized into different functional layers, each responsible for performing a different set of functions, as we will see in this lesson. We will also look at the principles of congestion control, managed at the transport layer.


18 videos, 1 reading expand

1. Reading: Power of Networks
2. Video: Divide And Conquer
3. Video: Layered Protocol Stack
4. Video: Transport & Network Layers
5. Video: Headers
6. Video: Processing Layers
7. Video: Controlling Congestion
8. Video: Traffic Jam & Bucket Analogy
9. Video: End Hosts
10. Video: Sliding Window
11. Video: Cautious Growth of Window Size
12. Video: Inferring Congestion
13. Video: Congestion Control Versions
14. Video: Loss-Based Congestion Inference
15. Video: Delay-Based Congestion Inference: Part I
16. Video: Delay-Based Congestion Inference: Part II
17. Video: Delay-Based Congestion Inference: Part III
18. Video: Distributed Congestion Control
19. Video: Summary

It's a Small World



Six degrees of separation is a widely told story in popular science. How can it still be a "small world" with the enormity of the Internet today? It depends on how the social networks are structured, and on how we search for short paths, as we will see in this lesson.


17 videos, 1 reading expand

1. Reading: Power of Networks
2. Video: Introduction
3. Video: Milgram's Experiment
4. Video: "Small world" in Culture
5. Video: Structural vs. Algorithmic Small Worlds
6. Video: Triad Closures and Homophily
7. Video: Average Shortest Path
8. Video: Random Graphs
9. Video: Clustering Coefficient: Part A
10. Video: Clustering Coefficient: Part B
11. Video: Regular Graph: Part A
12. Video: Regular Graph: Part B
13. Video: Watts-Strogatz Model: Part A
14. Video: Watts-Strogatz Model: Part B
15. Video: Discovering Short Paths
16. Video: Watts-Dodds-Newman Model: Part A
17. Video: Watts-Dodds-Newman Model: Part B
18. Video: Summary

Graded: Problem Set #6

WEEK 8


Final Exam
The final covers the last six lessons in the course (those after the midterm). Like the midterm, the questions are all multiple choice, and tend to be easier than the homework questions but harder than the in-video quizzes.

Graded: Final