DATA COMMUNICATION AND WIRELESS SENSOR NETWORKS

1. DATA COMMUNICATION AND WIRELESS SENSOR NETWORKS • OBJECTIVE: • To learn Data communication methods and Algorithm • To learn set up, installation,configuratiuon of WSN • To study different programming tools

2. Unit I Syllabus • Basics Of communication: Communication system, baseband broadband and carrier Communication, transmission modes SNR • Digital Modulation Techniques: PCM, DPCM, ADPCM, • Delta Modulation, Adaptive Delta Modulation, Bandwidth requirement of digital modulation techniques. • Quantization Line Coding techniques: Bipolar, Unipolar, RZ, NRZ, Manchester, AMI, B8ZS, Block coding techniques. • Multiplexing techniques: TDM, FDM, WDM, and CDMA, TD-SCDMA, LTETDD,LTE-FDD. • LAN standards: Ethernet, Wireless LAN, WiMax, ZigBee, Bluetooth, Infrastructure based (satellite n/w, Cellular n/w) and Infrastructure less (Adhoc n/w) wireless topologies. • VLAN, Basics of VPN, VPN tools and Applications.

3. 1-1 DATA COMMUNICATIONS The term telecommunication means communication at a distance. The word data refers to information presented in whatever form is agreed upon by the parties creating and using the data. Data communications are the exchange of data between two devices via some form of transmission medium such as a wire cable. Topics discussed in this section: Components Data RepresentationData Flow

4. Figure 1.1 Five components of data communication

5. Figure 1.2 Data flow (simplex, half-duplex, and full-duplex)

6. Figure 1.3 Types of connections: point-to-point and multipoint

7. Communication System

8. Signals and types

9. To be transmitted, data must be transformed to electromagnetic signals. Data can be analog or digital. Analog data are continuous and take continuous values. Digital data have discrete states and take discrete values. Signals can also be analog or digital. Analog signals can have an infinite number of values in a range; digital signals can have only a limited number of values. ANALOG AND DIGITAL

10. ANALOG AND DIGITAL • Both analog and digital signal can be periodic or non periodic. • A periodic signal completes a pattern within a measurable time frame called period and repeats the pattern over subsequent identical period. • Completion a full pattern is called a cycle. • In data communications, we commonly use periodic analog signals and nonperiodic digital signals.

11. Periodic analog signals can be classified as simple or composite. A simple periodic analog signal, a sine wave, cannot be decomposed into simpler signals. A composite periodic analog signal is composed of multiple sine waves. The sine wave is the most fundamental form of a periodic analog signal. A sine wave can be represented by three parameters: the peak amplitude, the frequency and the phase PERIODIC ANALOG SIGNALS

12. PERIODIC ANALOG SIGNALS Figure 3.2 A sine wave Figure 3.3 Two signals with the same phase and frequency, but different amplitudes • Frequency and period are the inverse of each other. • Frequency is the rate of change with respect to time. Change in a short span of time means high frequency. Change over a long span of time means low frequency.

13. PERIODIC ANALOG SIGNALS Figure 3.4 Two signals with the same amplitude and phase, but different frequencies

14. Frequency and phase • If a signal does not change at all, its frequency is zero. • If a signal changes instantaneously, its frequency is infinite. • Phase describes the position of the waveform relative to time 0. Figure 3.5 Three sine waves with the same amplitude and frequency, but different phases