Technical Report on Dark Energy Camera E Manoj

TECHNICAL REPORT ON DARK ENERGY CAMERA

E MANOJ

(13L228)

Dissertation submitted in partial fulfillment of the requirements for the degree of

BACHELOR OF ENGINEERING

Branch: ELECTRONICS AND COMMUNICATION ENGINEERING

of Anna University

June - 2014

DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING PSG COLLEGE OF TECHNOLOGY (Autonomous Institution)COIMBATORE – 641 004

TECHNICAL REPORT ON DARK ENERGY CAMERA

Bona fide record of work done by

D GOVARDHANAN (13L115)

Dissertation submitted in partial fulfillment of the requirements for the degree of

BACHELOR OF ENGINEERING

Branch: ELECTRONICS AND COMMUNICATION ENGINEERING

of Anna University

June 2014

...……………………… …………..………………. Dr. S.Subha Rani

Faculty guide Head of the Department

ACKNOWLEDGEMENT

I would like to extend my sincere thanks to Dr. R. RUDHRAMOORTHY, Principal, PSG College of Technology, for his kind patronage.

I am indebted to Dr. S. SUBHA RANI, Professor and Head of the Department of Electronics and Communication Engineering, for her continued support and motivation.

I would like to express my gratitude to my technical report guide Mrs. RAMYA, Assistant Professor(SR), Mr. K.R. RADHAKRISHNAN, Assistant Professor and Dr. U. SARAVANAKUMAR, Assistant Professor Department of Electronics and Communication Engineering, for their constant motivation, direction and guidance throughout the entire course of our technical report.

I am grateful to the support extended by my class advisor Dr. SIVARAJ, Assistant Professor, Department of Electronics and Communication Engineering.

I thank all the staff members of the Department of Electronics and Communication Engineering for their support.Last but not the least I thank the Almighty and my family members who have been a guiding light in all our endeavors.

iii

ABSTRACT

Wi-Fi, also spelled Wifi or WiFi, is a local area wireless technology that allows an electronic device to exchange data or connect to the internet using 2.4 GHz UHF and

5 GHz SHF radio waves. The name is a trademark name, and is a play on the audiophile term Hi-Fi. The Wi-Fi Alliance defines Wi-Fi as any "wireless local area network (WLAN) products that are based on the Institute of Electrical and Electronics Engineers' (IEEE)

802.11standards".However, since most modern WLANs are based on these standards, the term "Wi-Fi" is used in general English as a synonym for "WLAN". Only Wi-Fi products that complete Wi-Fi Alliance interoperability certification testing successfully may use the "Wi-Fi CERTIFIED" trademark.

Many devices can use Wi-Fi, e.g., personal computers, video-game consoles, smartphone, some digital cameras, tablet computers and digital audio players. These can connect to a network resource such as the Internet via a wireless network access point.

Table of contents

Acknowledgement 3 Abstract 4

INTRODUCTION

Wireless Technology is an alternative to wired technology, which is commonly used for connecting devices in wireless mode.Wi-Fi Wireless Fidelity is a generic term that refers to IEEE 802.11 communications standard for Wireless Local Area

Networks.(WLANs).Wi-Fi network connect computers to each other ,to internet and to wired networks. The term Wi-Fi, commercially used at least as early as August

2000. A Wi-Fi-enabled device can connect to the Internet when within range of a wireless network which is configured to permit this. The coverage of one or more

(interconnected) access points called hotspots—can extend from an area as small as a few rooms to as large as many square kilometres. Coverage in the larger area may require a group of access points with overlapping coverage.

Figure 1

Wifi network:

Wi-Fi networks use radio technologies to transmit and receive data at high speed.

 IEEE 802.11b  IEEE 802.11a  IEEE 802.11g

IEEE-(Institute of electrical and Electronic Engineers). IEEE 802.11

IEEE 802.11b-1999 or 802.11b, is an amendment to the IEEE 802.11 wireless networking specification that extends throughput up to 11 Mbit/s using the same

2.4GHz band This specification is marketed as Wi-Fi and has been implemented all over the world. A related amendment was incorporated into the IEEE 802.11-2007 standard.

802.11 is a set of IEEE standards that govern wireless networking transmission methods. They are commonly used today in their 802.11a, 802.11b, 802.11g,

802.11n and 802.11ac versions to provide wireless connectivity in the home, office and some commercial establishments. 802.11b is used in a point-to-multipoint configuration, wherein an accesspoint communicates via an omnidirectional antenna with mobile clients within the range of the access point. Typical range depends on the radio frequency environment, output power and sensitivity of the receiver.

Allowable bandwidth is shared across clients in discrete channels. A directional antenna focuses output power into a smaller field which increases point-to-point range. Designers of such installations who wish to remain within the law must however be careful about legal limitations on effective radiated power.

IEEE 802.11a

IEEE 802.11a-1999 or 802.11a was an amendment to the IEEE 802.11

wireless local network specifications that defined requirements for an

orthogonal frequency division multiplexing (OFDM) communication system.

It was originally designed to support wireless communication in the

unlicensed national information infrastructure (U-NII) bands (in the 5–6 GHz

frequency range) as regulated in the United States by the Code of Federal

Regulations. The 802.11a amendment to the original standard was ratified in

1999. The 802.11a standard uses the same core protocol as the original

standard, operates in 5 GHz band, and uses a 52-subcarrier orthogonal

frequency-division multiplexing (OFDM) with a maximum raw data rate of 54

Mbit/s, which yields realistic net achievable throughput in the mid-20 Mbit/s

Using the 5 GHz band gives 802.11a a significant advantage, since the

2.4 GHz band is heavily used to the point of being crowded. Degradation

caused by such conflicts can cause frequent dropped connections and

degradation of service.

The effective overall range of 802.11a is slightly less than that of

802.11b/g; 802.11a signals cannot penetrate as far as those for 802.11b

because they are absorbed more readily by walls and other solid objects in

their path and because the path loss in signal strength is proportional to the

square of the signal frequency.

IEEE 802.11g:

IEEE 802.11g-2003 or 802.11g is an amendment to the IEEE 802.11 specification that extended throughput to up to 54 Mbit/s using the same 2.4 GHz band as 802.11b. This specification under the marketing name of Wi-Fi has been implemented all over the world.

The 802.11g protocol is now Clause 19 of the published IEEE 802.11-2007 standard, and

Clause 19 of the published IEEE 802.11-2012 standard. 802.11g is the third modulation standard for wireless LANs.

It works in the 2.4 GHz band (like 802.11b) but operates at a maximum raw data rate of 54 Mbit/s. Using the CSMA/CA transmission scheme, 31.4 Mbit/s[1] is the maximum net throughput possible for packets of 1500 bytes in size and a 54 Mbit/s wireless rate

It is moré expensive and used only in highly authorized organisation.

WiFi- router:

A wireless router is a device that performs the functions of a router but also includes the functions of a wireless access point. It is commonly used to provide access to the Internet or a computer network. It does not require a wired link, as the connection is made wirelessly, via radio waves. It can function in a wired LAN (local area network), in a wireless-only LAN (WLAN), or in a mixed wired/wireless network, depending on the manufacturer and model.

Most current wireless routers have the following characteristics:

 one or multiple NIC supporting Fast Ethernet or Gigabit Ethernet integrated into the main SoC.  One or multiple WNICs supporting a part of the IEEE 802.11-standard family also integrated into the main SoC or as separate chips on the Printed circuit board. Some wireless routers come with either xDSL modem, DOCSIS modem, LTE modem, or fiber optic modem integrated.  Some dual-band wireless routers operate the 2.4 GHz and 5 GHz bands simultaneously.ct card connected over a MiniPCI or MiniPCIe interface.

 Some wireless routers have a USB port specifically designed for connecting 3G mobile broadband modem aside from connecting the wireless router to a xDSL modem.

VIRTUAL WIFI ROUTER:

Virtual Wi-Fi Router is a free utility that is designed to turn any Wi-Fi enabled Windows PC into a wireless access point for Internet access.

This utility has a very clean and easy to use interface that allows you to assign a password to your virtual access point to prevent unauthorized access. The interface even offers a tab that lets you confirm who is using the wireless access point.

HOTSPOT SHIELD:

Hotspot Shield is a free utility that is designed to help protect your privacy when you connect to public Wi-Fi hotspots.

The program has a very simplistic interface, but that doesn't mean that it doesn't work well. Once protection is enabled you can click on a Test Protection link to verify that the utility is working. Doing so takes you to TestMyIP.org. In my case, my static IP was hidden and TestMyIP.org thought that I was located somewhere in Los Angeles instead of on the east coast where I actually reside.

WIFI GUARDIAN:

WiFi Guardian is designed to protect your privacy by redirecting your Internet connectivity to a proxy server that allows your session to be encrypted and made anonymous. The software does require you to create an account and to choose a WiFi Guardian server to use as a proxy. Servers are available in the United Kingdom, France, and Australia. 11

WiFi Guardian sells for $49.95, but a free 3-day trial is available for download.

XIRRUS WIFI INSPECTOR:

Xirrus Wi-Fi Inspector is a free tool designed to help you to verify the health of your wireless network. Upon launching the tool, you must select your computer's wireless network adapter. After doing so, the utility will display some vital statistics for your Wi-Fi connection, such as the SSID, IP address, etc.

The utility also keeps track of your wireless signal strength on a graph at the bottom of the interface. Buttons at the top of the interface link to external Web sites that can be used to test your connection speed and quality.

Wifi profile manager:

Wifi profile manager is a free utility that is designed to manage wireless network connections on a computer that is running Windows 8. The utility can make a Wi-Fi connection the default for your computer and can move access points up and down a list by order of priority. A Properties screen displays vital statistics (such as the encryption key) for connections.

One of the nice things about this utility is that it is completely portable. The utility consists of a single executable file that can be run on any Windows 8 PC without having to be installed.

WiFi modes of operation

There are several kinds of hardware that may be used to implement a WiFi wireless network:

 Wireless adapters or network interface controllers (NICs for short) are network cards with the 802.11 standard which let a machine connect to a wireless network. WiFi adapters are available in numerous formats, such as PCI cards, PCMCIA cards, USB adapters, and CompactFlash cards. A station is any device that has such a card.  Access points (AP for short; sometimes called hotspots) can let nearby wifi- equipped stations access a wired network to which the access point is directly connected.

The 802.11 standard defines two operating modes:

 Infrastructure mode, in which wireless clients are connected to an access point. This is generally the default mode for 802.11b cards.

 Ad hoc mode, in which clients are connected to one another without any access point.

Infrastructure mode

In mode infrastructure, each station computer (STA for short) connects to an access point via a wireless link. The set-up formed by the access point and the stations located within its coverage area are called the basic service set, or BSS for short. They form one cell. Each BSS is identified by a BSSID, a 6-byte (48-bite) identifier. In infrastructure mode, the BSSID corresponds to the access point's MAC address.

It is possible to link several access points together (or more precisely several BSS's) using a connection called a distribution system (DS for short) in order to form an extended service set or ESS. The distribution system can also be a wired network, a cable between two access points or even a wireless network.

AD-HOC mode:

Wireless client machines connect to one another in order to form peer to peer network. The set-up formed by the stations is called the independent basic service set, or IBSS for short.

An IBSS is a wireless network which has at least two stations and uses no access point. The IBSS therefore forms a temporary network which lets people in the same room exchange data. It is identified by an SSID, just like an ESS in infrastructure mode.

In an ad hoc network, the range of the independent BSS is determined by each station's range. That means that if two of the stations on the network are outside each other's range, they will not be able to communicate, even if they can "see" other stations. Unlike infrastructure mode, ad hoc mode has no distribution system that can send data frames from one station to another. An IBSS, then, is by definition a restricted wireless network.

Adavantages of wifi:

 High security when compared to other wireless devices  High Bandwidth  Use unlicensed part of the radio spectrum  The main advantages of using Wi-Fi technology is the lack of wires. This is a wireless connection that can merge together multiple devices.  Wi-Fi network is particularly useful in cases where the wiring is not possible or even unacceptable. For example, it is often used in the halls of conferences and international exhibitions. It is ideal for buildings that are considered architectural monuments of history, as it excludes the wires.

DISADVANTAGES:

 High power consumption  They have limited range  Requires high hardware equipment Call quality is greatly influenced by the environment, is particularly sensitive to electromagnetic radiation generated by household appliances. This primarily affects the speed of data transmission.  Despite the global standardization, many devices from different manufacturers are not fully compatible, which in turn affects the speed of communication.  Wi-Fi has a limited radius of action and it is suitable for home networking, which is more dependent on the environment. For example, a typical home router with Wi-Fi in the room has a range of up to 45 meters and up to 450 meters outside.  At high density Wi-Fi-points operating in the same or adjacent channels, they can interfere with each other. This affects the quality of the connection. This problem is common in apartment buildings, where many residents are using this technology.

CONCLUSION:

Wi-Fi is one of the fastest growing technologies. The demand for connecting devices without use of cables is increasing everywhere as people want to connect in wireless.

REFERENCES: www.wikipwdia.com www.wifitech.com www.howthestuffworks.com www.wifiindailyworld.com