Network Evolution Standards and Layered Architectures 2 Evolution Organization and Standards 1 Outline Network Evolution Standards What makes communication systems work How the network evolved How network provided more services for less cost Predict where technology is going Organization Objectives Standards Organizations Layered Architectures OSI reference layered model TCP IP network architecture layered model Goal Understand how networks are described Evolution Organization and Standards 2 Elements of Current Communication Paradigm Session Initiation Protocol SIP for Voice over IP VoIP registrar INVITE sip tom startup com c IN IPv4 192 168 12 5 m audio 35092 RTP AVP 0 2 3 5 ringing 4 1 6 7 SIP 2 0 200 OK INVITE sip tom 192 168 15 17 c IN IPv4 192 168 12 5 m audio 35092 RTP AVP 0 proxy SIP 2 0 200 OK 8 ACK 9 Media flow Modified From Communication Networks Fundamentals Concepts and Key Architectures Authors A Leon Garcia and I Widjaja Evolution Organization and Standards 3 Elements of a Communications System Transmission Switching Routing Signaling Evolution Organization and Standards 4 Evolution of Transmission Time Access Technology Twisted pair copper Coax Wireless Others Powerline Satellite Evolution Organization and Standards 5 Transmission Network Resources Time When and how long a user gets to talk Frequency What part of the spectrum channel is used What code is used Evolution Organization and Standards 6 Transmission Network Resources TDM Time Division Multiplexing FDM Frequency Division Multiplexing Typical for analog voice Time Normally users are not directly involved in resource allocation Modified from Computer Networks A S Tannenbaum 4th Ed Prentice Hall 2003 Evolution Organization and Standards 7 FDMA and TDMA Multiple Access MA is a channel access method allowing several users to share the resource in time or frequency The users transmit in order each using his own frequency channel time slot Example FDMA Frequency Division Multiple Access 4 users Channel frequency time TDMA Time Division Multiple Access Frame Time Slot frequency Normally in MA networks users are directly involved in resource allocation time Modified from Computer Networking A Top Down Approach Featuring the Internet Evolution Organization and Standards 2nd edition Jim Kurose Keith RossAddison Wesley July 2002 8 Time Transmission Network Resources Spectrogram of Downlink Physical Channel for Long Term Evolution LTE 10 ms 20 Mhz Frequency From Peter Cain Using Wireless Signal Decoding to Verify LTE Radio signals Agilent Technologies July 2011 Evolution Organization and Standards 9 Transmission Network Resources Code Division Multiple Access CDMA Assume three users share same medium in time and frequency Users are synchronized use different 4 bit orthogonal codes 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Bit time Bit time Code Section 6 4 3 Modified From Communication Networks Evolution Organization and Standards Fundamentals Concepts and Key Architectures Authors A Leon Garcia and I Widjaja 10 Transmission Network Resources Downlink e g base station smartphone Uplink e g smartphone base station Frequency division duplexing FDD Downlink on frequency carrier 1 f1 Uplink on frequency carrier 2 f2 Time division Duplexing TDD Downlink is time slots 1 k Uplink in time slots k 1 M Evolution Organization and Standards 11 LTE Operating Bands 15 use FDD and 8 use TDD LTE definitions UE User Equipment e g smartphone eNB Evolved NodeB Base station TDD Same Band for BS UE UE BS From Agilent 3GPP Long Term Evolution System Overview Product Development and Test Challenges Application Note Evolution Organization and Standards 12 Switching Manual Step by step Crossbar with stored program control Digital Switching Packet Switching Optical Switching Evolution Organization and Standards 13 Evolution Organization and Standards 14 Stepby Step Switch Stored Program Control System Evolution Organization and Standards 15 Evolution Organization and Standards 16 Crossbar Switch Digital Switching Evolution Organization and Standards 17 Packet Switching Statistical Multiplexing Server b s Arriving Packets Buffer Queue Departing Packets Packet switching provides flexibility and the dynamic allocation of bandwidth The Internet is a packet switched network Packet switching is leading to the integration of all services on one infrastructure One infrastructure for voice data video Examples VoIP and Video over IP over the top Evolution Organization and Standards 18 Optical Switching All current switches are electronic Current switches require photon to electron conversions optical to electronic E O interfaces Optical switching will eliminate these interfaces Faster Cheaper Lower power required Evolution Organization and Standards 19 Signaling Signaling Control Governs network elements e g telephone switches or packet switches routers Sets up a communications capability Maintains a communications capability Ends tears down a communications capability The signaling network carries the messages that controls the network elements Pulses In the same transmission path as voice signal Tones In the same transmission path as voice signal Computer Messages Outside of the transmission path Common Channel interoffice signaling CCIS Signaling System 7 SS7 Session Initiation Protocol SIP for VoIP H 323 Others IP routing protocol messages packets sent between processors that control IP routers Evolution Organization and Standards 20 Evolution Organization and Standards 21 Survivability FIBER CUT Jan 4 1991 New York metro area 6 million homes without long distance service New York Mercantile Exchange and New York Commodity Exchange shut down Fiber cuts are common Survivability SS7 FAILURE June 10 1991 California 2 million homes without phone service June 26 1991 Baltimore 10 million homes in 4 states without service U S government phones affected Survivability SWITCH and POWER FAILURE September 17 1991 New York metro area 2 million homes without long distance service 3 major New York airports close for 6 hours Evolution Organization and Standards 22 Architecture of the Internet e g Sprint or ATT Point of Presence e g Sprint or ATT Peering point Network Access Point or cable system Voice Image Data Video Evolution Organization and Standards Modified from Computer Networks A S Tannenbaum 4th Ed Prentice Hall 2003 23 What s the Internet nuts and bolts view how do packet flow over the internet billions of connected computing devices hosts end systems router