15-441 Lecture 6 Physical Layer( Cont)& Data link layer Based on slides from previous 441 lectures ecture 6 15-441e2008
Lecture 6 15-441 © 2008 15-441 Lecture 6 Physical Layer (Cont) & Data Link Layer Based on slides from previous 441 lectures 1
Last time Physical Layer Modulation Application Bandwidth Presentation Session Nyquist/Shannon Transport Multiple×ing Network M edla Datalink Physical
Last Time • Physical Layer – Modulation – Bandwidth – Nyquist/Shannon – Multiplexing – Media Application Presentation Session Transport Network Datalink Physical
Today(& Tomorrow) 1. Physical layer Application (Encoding Presentation 2. Datalink layer Session introduction Transport framing error Network coding, MAC, Datalink switched networks Physical 3. Broadcast-networks home networkin
Today (& Tomorrow) 1. Physical layer. (Encoding) 2. Datalink layer introduction, framing, error coding, MAC, switched networks. 3. Broadcast-networks, home networking. Application Presentation Session Transport Network Datalink Physical
From Signals to Packets Packet Transmission Sender Receiver Packets 010001010101110010101010101110111000000111101010111010101010110101101 Header/Body Header/Body Header/Body Bit stream 00101110 "Digital" Signal Analog Signal ecture 6 15441@2008
From Signals to Packets Analog Signal “Digital” Signal Bit Stream 0 0 1 0 1 1 1 0 0 0 1 Packets 0100010101011100101010101011101110000001111010101110101010101101011010111001 Header/Body Header/Body Header/Body Sender Receiver Packet Transmission Lecture 6 15-441 © 2008 4
How Encode? Seems obvious, why take time with this? 0 0 00 85 0 -85 ecture 6 15441@2008
How Encode? •Seems obvious, why take time with this? Lecture 6 15-441 © 2008 V 0 .85 -.85 0 1 0 0 0 1 1 0 1 5