I. Introduction

1. Computer Network and Distributed System

Example: World Wide Web, Hadoop

2. Uses

  • Business Application

    • Resource Sharing (Client-Server Model)
    • Communication Medium
    • Electric Commerce

  • Home Application

    • Connectivity (Peer-to-Peer)
    • Person-to-Person communication
      • Instant Messaging (Twitter)
      • Social Network (Facebook)
      • Wiki (Wikipedia)
    • Electric Commerce (B2C, B2B, G2C, C2C, P2P)
    • Entertainment
    • Ubiquitous Computing (RFID, IOT)

  • Mobile Users

    • Wireless Network
    • Text Messaging (SMS)
    • Mobile Commerce
    • Sensor Network
    • Wearable Computers

  • Social Issues

    • Network Neutrality
    • DMCA
    • Privacy
    • Spam
    • Secruity
    • Law (Electric Gambling)

3. Hardware

  • Sorted by Type
    • Broadcast
    • Point-to-Point
  • Sorted by Scale
    • Internetworks
    • Wide Area Network
    • Metropolitan Area Network
    • Local Area Network
    • Personal Area Network

4. Software

  • Layer, Protocol, Interface, Service Most networks are organized as a stack of layers. A protocol is an agreement between the communicating parties on how communication is to proceed. The interface defines which primitive operations and services the lower layer makes available to the upper one. A service is a set of primitives(operations) that a layer provides to the layer above it.
  • Design Issues
  1. Reliability
    • Error Detection
    • Error Correction
    • Routing
  2. Evolution
    • Addressing or Naming
    • Internetworking
  3. Resource Allocation
    • Multiplexing
    • Flow Control
    • Congestion
    • Quality of Service
  4. Secure

  • Connection Oriented VS Connectionless Realiable communication may not be availble in a given layer; The delays inherent in providing a reliable service may be unacceptable.

    1. Connection Oriented
      • Byte Stream VS Message Stream
      • Voice over IP
    2. Connectionless
      • Datagram
      • Request-Reply

  • Service Primitive

5. Reference Model

OSITCP/IPUsed in the book
ApplicationApplicationApplication
Presentation--
Session--
TransportTransportTransport
NetworkNetworkNetwork
Data LinkLinkData Link
Physical-Physical

6. Network Standardization

II. The Physical Layer

It defines the electrical, timing and other interfaces by which bits are sent as signals over channels.

1. The Theoretical Basis for Data Communication

  • Fourier Analysis

  • Bandwidth-Limited Signals

    • Bandwidth The width of the frequency range transmitted without being strongly attenuated is called the bandwidth.
    • Baseband Signals that run from 0 up to the maximum frequency are called baseband signals.
    • Passband Signals that are shifted to occupy a higher range of frequencies, as is the case of all wireless transmissions, are called passband signals.

  • The Maximum Data Rate of a Channel

    • Nyquist’s theorem $$maximum\ data\ rate=2B\log\_2V\ bits/sec$$
    • Shannon’s theorem $$maximum\ data\ rate=B\log\_2(1+S/N)\ bits/sec$$
    $$10\log\_{10}S/N=1\ dB$$

2. Digital Modulation

  • Baseband
    • NRZ
    • NRZI
    • Manchester
    • Bipolar
    • 4B/5B
  • Passband
    • ASK
    • FSK
    • PSK
    • Constellation Diagram

3. Multiplexing

  • FDM
  • TDM
  • CDMA

4. Switching

1. Framing

IV. The Medium Access Control Sublayer

V. The Network Layer

VI. The Transport Layer

VII. The Application Layer

VIII. Network Security