Data Communication and Optical Network
- 1. Module 1 Data Communication By: Ms. Pradnya Saval
- 2. Contents • Defining Data Communication • Transmission Hierarchy • Optical Networks: • SONET/SDH Architecture • SONET Structure • SONET Format • SONET Hardware
- 3. Data Communication • Data communications refers to the transmission of this digital data between two or more computers and a computer network or data network is a telecommunications network that allows computers to exchange data. • The physical connection between networked computing devices is established using either cable media or wireless media. • The best-known computer network is the Internet.
- 4. Need of Data Communication • Increased LAN and application interconnectivity between departments, customers, and suppliers. • The movement of mainframe applications to a client-server architecture. • The movement of applications on a network. • People can communicate and share information virtually instantaneously across the entire globe. • Education and business concerns can take place no matter where the individual parties are located.
- 5. Basics of a Network • Elements of a network: • Station • Routers • Categories • LAN • MAN • WAN • Topology • Bus • Ring • Star • Mesh • Transmission Media • Guided Media • Twisted Pair • Coaxial • Fibre Optic • Unguided Media • Radiowaves • Micowaves • Infrared
- 6. What is an Optical Network? • An Optical Network is basically a communication network used for the exchange of information through an optical fiber cable between one end to another. • It is one of the quickest networks used for data communication. • The data signal through an optical fiber is transmitted in the form of light pulses. So, optical networks are used in order to have optical signal transmission.
- 7. Advantages of Optical Network • Ease of transmitting. • Permits large data carrying capacity and longer distance transmission than other cables. • Low production cost of the cable. • Supports high bandwidth. • Signal can be transmitted to longer distances. • Networking system is more flexible than other transmission systems.
- 8. SONET - Introduction • Synchronous Optical Network • Enhanced version: Synchronous Digital Hierarchy • SONET is used as a transport network to carry loads from other WANs. • A standard to be used for fiber optics • It is a technology for service providers to internationally standardize and control broadband network transport through common fiber interface called as midspan meet.
- 9. Advantages of SONET/SDH • Reduction of equipment's needed. • Increased network reliability and availability. • Centralized fault isolation and management of payload (traffic carried) • Allows easy access for switching and multiplexing • Flexible architecture able to accommodate future requirements.
- 10. Transmission Methods • Synchronous • Plesiochronous • Asynchronous • SONET/SDH is a synchronous network using synchronous TDM multiplexing. • All clocks in the system are locked to a master clock.
- 11. SONET Architecture • The architecture of SONET includes: • Signals • Devices • Connections
- 12. SONET Signals • SONET defines a hierarchy of electrical signaling levels called as synchronous transport signals (STSs). • Each STS level (STS-1 to STS-192) supports certain data rate specified in megabits/sec. • Corresponding optical signals are called as Optical carriers (OCs). • SDH specifies a similar system called as synchronous transport module (STM).
- 13. SONET data rates
- 14. SONET Devices
- 15. SONET Connections • The devices in SONET are connected using the following connections: • Sections • Lines • Paths
- 16. SONET Layers • The SONET standard includes four functional layers: • Path • Line • Section • Photonic (physical)
- 18. STS-1 frames in Transmission
- 19. SONET Frame Format - Key Points • A SONET STS-n signal is transmitted at 8000 frames per second. • Each byte in a SONET frame can carry a digitized voice channel. • In SONET, the data rate of an STS-n signal is n times the data rate of an STS-1 signal. • In SONET, the duration of any frame is 125 μs.
- 20. SONET Frame Format (Cont..) • Example1: Find the data rate of an STS-1 signal. • Solution: STS-1, like other STS signals, sends 8000 frames per second. Each STS-1 frame is made of 9 by (1 × 90) bytes. Each byte is made of 8 bits. The data rate is:
- 21. SONET Frame Format (Cont..) • Example2: Find the data rate of an STS-3 signal. • Solution: STS-3, like other STS signals, sends 8000 frames per second. Each STS-3 frame is made of 9 by (3 × 90) bytes. Each byte is made of 8 bits. The data rate is:
- 22. SONET Frame Format (Cont..) • Example3: What is the duration of an STS-1 frame? STS-3 frame? STS-n frame? • Solution: In SONET, 8000 frames are sent per second. This means that the duration of an STS-1, STS-3, or STS-n frame is the same and equal to 1/8000 s, or 125 μs.
- 24. Section Overhead in STS-n Frame Format
- 25. Line Overhead in STS-n Frame Format
- 26. Path Overhead in STS-n Frame Format