Radio And Optical Wireless Communication

4. Use the Internet to research one to two applications of the identified wireless technology. List each application found. Reference the websites you used to locate this information.

0 Use the Internet to research one to two applications of the illustrated wireless technology. List each application found. Be sure to reference the Web site(s) where you found this information.

The increased demand for radio spectrum has resulted from the evolution of feature-rich and high-data-rate wireless applications. The spectrum is limited, and the current radio spectrum regulations make its use less productive. This has necessitated the development of dynamic spectrum allocation policies to make the utilization of the existing spectrum in a better way. As per the current spectrum allocation regulations, specific bands are assigned to particular services and only licensed users are granted access to licensed bands. Cognitive radio (CR) is expected to modernize the way spectrum is allocated. In a CR network, the cognitive radio part allows the unlicensed users (secondary users) to access spectrum bands allocated to the licensed

Lastly in section (C), path loss exponents are same as that of section (B) but the distance from transmitter and receiver are varied for individual value of path loss exponent. From the graph, it shows us that for n=2, the distance of reduced output power is in the range from 0.1 to 1.5km, similarly for n=3 it is in the range of 1.5 to 2.5 km, and for n=4 it is from 2.5 to

Wireless networking hardware requires the use of underlying technology that deals with radio frequencies as well as data transmission. The most widely used standard is 802.11 produced by the Institute of Electrical and Electronic Engineers (IEEE). This is a standard defining all aspects of Radio Frequency Wireless networking

The LI-FI system finds a variety of uses in many fields from access to internet by the general public using street lamps to auto-pilot cars which communicate through their headlights. Instead of that, in areas such as medicine and aircrafts where WI-FI cannot be used, LI-FI is an alternative which can provide faster data access rates. Some of the applications are discussed below:

security mechanisms are discussed. Underwater wireless communication networks are particularly vulnerable to malicious attacks due to the high bit error rates, large and variable propagation delays, and low bandwidth of acoustic channels. A complete survey of securing underwater wireless communication networks is presented, and the research challenges for secure communication in this environment are outlined.Acoustic channels have low bandwidth. The link quality in underwater communication is severely affected by multipath, fading, and the refractive The unique characteristics of the underwater acoustic communication channel, and the differences between underwater sensor networks and their ground-based counterparts require for the development of efficient and reliable properties of the sound channel. As a result, the bit error rates of acoustic links are often high, and losses of connectivity arise.Radio waves do not propagate well underwater due to the high energy absorption of water. Therefore, underwater communications are based on acoustic links characterized by large propagation delays. The above mentioned characteristics of UWCNs have several security implications. UWCNs suffer from the vulnerabilities which decreases the reliability. So, this article have discussed for security in UWCNs, underlining the specific characteristics of these networks, possible attacks, countermeasures and challenges.

Ultrawide band is a unique technology which is used for commercial communications. In this ,I will explain about UWB and how to integrate it with CMOS technology.This is by designing a UWB receiver using CMOS technology. Use Verilog to build behavioral model of LNA,mixer,bandpass filter,integrator.Instante the components in Cadence and run simulation in time domain. In this paper ,I have specified the design considerations of

Shannon proved that data could be transmitted through a channel with speeds closing the channel’s capacity, with no transmission errors and low transmitting power by using the right code (Shannon, 1948). [2] For an Additive White Gaussian Noise (AWGN) channel the formula is R. In this paper, introducing Turbo codes they showed that it is possible to approach Shannon’s limit within 0,5 dB, for a bit error rate of 1:100000 (Berrou, Glavieux and Thitimajshima, 1993) [4]. Albeit Turbo codes were innovative, they actually used two previously known techniques; the concatenated coding and the iterative decoding, which will be briefly described below.

1,2,3Electronics & Communication Engineering, Seth Jai Parkash Mukand Lal Institute of Engineering & Technology, Radaur, Yamunanagar, Haryana, India-135133,

Through the distribution fiber (DF), each output port of RN1 goes to a different remote node 2 (RN2) which includes a power splitter (PS), and then each output port of the PS is connected to a different ONU by the last mile fiber (LMF). According to the RN1 configuration, we have three variants of a TWDM-PON architecture: a) Wavelength Selected TWDM-PON with PSs at the RN1; b) Wavelength Split TWDM-PON with arrayed waveguide grating (AWG) at the RN1; and c) Wavelength Switched TWDM-PON with wavelength selective switches (WSSs) at the RN1. The wavelength selected TWDM-PON is a fully flexible solution as the PS at RN1 broadcasts all wavelengths to all users, but has a high insertion loss and poor security due to the use of only PSs. The wavelength split TWDM-PON has a fixed wavelength allocation and thus will not be able to serve flexibility advantages. However, paper [4] shows that the full flexibility is not always required and a partial flexible solution can already give several advantages of flexibility. Overcoming the drawbacks of both wavelength selected and wavelength split, paper [5] proposed such a partially flexible solution with a WSS in RN1, which we refer as the wavelength switched TWDM-PON.

1Department of Electronics and Telecommunications, Symbiosis Institute of Technology, Symbiosis International University, Pune 412115, Maharashtra, India

Requires a large number of diodes which is a quadratic function of the number of levels. The diodes reverse recovery time can become problematic for high switching frequencies.

Optical communication is a form of telecommunication system in which light is used as the mode of transmission. An optical communication system consists of transmitter, receiver and channel. The transmitter basically works as an encoder, it encodes the message as an optical signal, the channel helps the signal to propagate and the receiver will work to decode the optical signal and get the message. [1]

ABSTRACT : - In this paper we simulatd an optical transmission system in optical fiber using different pulses .The optical fiber system used in telecommunication system has small size or dimension, low loss and low interference from outside environment. Optical fiber are of various configurations , we are using fiber bragg grating as the dispersion compensator in the fiber optic cable . We are using FBG in the simulation as because it offers more bandwidth .Optisystem software is used to analyse the optical transmission system . In the simulation of the communication system appropriate values of the input power , fiber cable length and attenuation coefficient is taken around the cable section and the output pwer , noise figure , gain is found out at the receiver. The transmitter frequency and cut off frequency of the receiver is made constant .