1. Submitted To:- Submitted By:- Mr. Navdeep Bhandari Aman Bassi (Faculty, I.T. Deptt.) Gurleen Kaur Gurpreet Kaur (BCA 2 A)

2. Sub Topics: 1. ALOHA 1.1 Introduction 1.2 Overview 1.3 Aloha Protocol 1.4 Types of Aloha 1.4.1 Pure Aloha 1.4.2 Slotted Aloha 1.5 Aloha Throughtput 2. SONET 2.1 Introduction 2.2 Architecture 2.3 Advantages 2.4 Sonet Protocol 2.5 Basic Frame

3. INTRODUCTION World ‘s First computer communication N/W using low cost ham like radios, named ALOHA net. First Functioning network in the USA Conceived & Implenmented at the University of Hawaii Campus at MANOA Purpose was to link the University mainframe Computer to client Computers

4. OVERVIEW...... Created in 1970 by Norman Abramson Idea was to Use low cost amateur radio like system to create C/N. Original version of ALOHA used two distinct frequencies in a hub/star configuration Used a shared medium for transmission

5. ALOHA PROTOCOL..... An OSI layer 2 protocol for LAN networks with broadcast topology Two Conditions 1. If you have a data to send, send the data 2. If the message collides with other transmission, try resending “later”

6. TYPES.... 1.Pure Aloha Pure Aloha Vulnerable Time = 2 x Tfr

7. 2. Slotted Aloha Slotted Aloha Vulnerable Time = Tfr

10. SONET (Synchronous Optical Network ) A Multiplexing Protocol for transferring multiple digital bit streams using laser or LED. Basically a TDM Supports both electrical & Optical signal Is a set of standards for interfacing OTC optical networks. Implemented for long haul traffic

11. Sonet Transmission Network is composed of several pieces of equipment, including: Terminal multiplexer (TM) Add-drop multiplexer (ADM) Repeater Digital cross-connect system (DCS)

12. Architecture In SONET The architecture used in SONET technology is SONET rings, known as "self-healing rings,“. use two or more transmission paths between network nodes, which are typically digital cross-connects (DCSs) or (ADMs). Two Fiber Unidirectional

13. Two Fiber Bidirectional

14. Four Fiber Bidirectional

15. ADVANTAGES Higher speed Provides advanced network management and maintenance features flexibility to accommodate any networks used in the three traditional telecommunications areas: 1. Long haul networks 2. Local Networks 3. Loop Carriers

16. SONET Protocol: Consist of Four Layer 1.Photonic layer 2. Section layer 3. Line layer 4. Path layer

17. THE BASIC FRAME 3 basic parts to each frame 1.Section overhead 2.Line overhead 3.Synchronous payload To Conclude....

18. REFERENCES 1. Kuo, Franklin F (1973). "The ALOHA system" in Computer Networks. Prentice-Hall. pp. 501–518. 2. Kuo, Franklin F (1995). "The ALOHA system". ACM Computer Communication. 3. International Engineering Consortium SONET Tutorial, undated, URL retrieved on 21 April 2007.