CU-MCA-SEM-I-Advanced Computer Networks-Second Draft

and other such devices are examples. Mobile computing enables data/information, music, video, and any other document to be sent without the need for a connection to a base or central network. In today's world, these computing gadgets are the most extensively utilised technologies. The following are some wireless/mobile computer technologies: GSM stands for Global System for Mobile Communications. GSM stands for \"Global System for Mobile Communications.\" It is a wireless data communication system based on current circuit switching. Throughout the mid-1980s, ETSI (European Telecommunications Standards Institute) established it in Europe. The GSM network includes four separate parks, each with its own set of functions: Mobile Station, BSS (Base Station Subsystem), NSS (Network Switching Subsystem), and OSS (Open-Source Software) (Operation and Support Subsystem). GSM stands for Global System for Mobile Communications, and it is the most frequently used mobile communication system. It works in the 900 MHz, 1800 MHz, and 1900 MHz frequency bands. For better mobile communication, GSM was created utilising TDMA (Time Division Multiple Access). It is the most frequently used and widely demanded mobile communication system today. It has a maximum data transfer speed of 9.6 kilobits per second (kbps) (Kilobits per second). CDMA (Code Division Multiple Access): CDMA stands for Code Division Multiple Access, and it is a sort of wireless computer technology. It was developed during WWII and is widely used because it provides better network quality, the most storage capacity besides voice and data communications than TDMA, reduces system noise and interference through power control, and provides more security by encoding user transmission data into some kind of unique code. CDMA does not assign a single frequency to each user, instead making use of the whole frequency spectrum accessible for transmission. It works in the 800 MHz to 1.9 GHz frequency range. Soft Handoff is used to reduce signal breaks. WLL (Wireless in Local Loop): For wireless communication systems, WLL is a frequently utilised technique. A Fixed Wireless Loop is another name for it. WLL is simple to build and instal, and it is very cost- effective because the expense of cable installation is not factored in. WLL delivers additional customer service services by allowing consumers to connect to the local telephone station over a wireless link. It has a high data rate and transmits high-quality data. Local Multipoint Distribution Service (LMDS) and Multichannel Multipoint Distribution Service (MMDS) are the two types of WLL approaches available (MMDS). GPRS (General Packet Radio Service): 151 CU IDOL SELF LEARNING MATERIAL (SLM)

GPRS (General Packet Radio Service) is a packet-based wireless communication system. ETSI is in charge of establishing it (European Telecommunications Standards Institute). A data rate of up to 114Kbps is possible using GPRS. It is extremely cost-effective, extremely stable, and capable of a maximum data rate of 114Kbps (Kilobits per second). It is based on Gaussian minimum-shift keying (GMSK), a modulation technology, and supports Internet Protocol (IP), X.25 (standard protocol for packet-switched data communication), and Point- to-Point Protocol (PPP). The two fundamental modules necessary to allow GPRS on a GSM or TDMA network are the Gateway GPRS Service Node (GGSN) and the Serving GPRS Service Node (SGSN). SMS (Short Message Service): SMS was designed for phones and mobile phones that use the GSM (Global System for Mobile Communication). This service allows two or more mobile devices to transmit text messages without the need for an Internet connection. This method of wireless communication is highly simple, user-friendly, pleasant, and effective. Communication takes up less time in this service. Sending text messages does not necessitate the use of an Internet connection. It supports the transmission of brief messages of up to 160 characters. Standard communication protocols are used in SMS. The Short Message Service Centre receives SMS (SMSC). 7.3 MAJOR ADVANTAGES OF MOBILE COMPUTING: The landscape of our day-to-day lives has been completely transformed by mobile computers. The following are some of the most significant advantages of mobile computing: Flexibility of location Users can now work from anywhere as long as they have access to the internet. Working without being in a fixed position is possible. Their mobility allows them to complete multiple things at once while also performing their assigned duties. Helps you save time The amount of time spent or squandered travelling between different places or to and from the office has been reduced. One can now use a secure channel or portal to access all of their critical documents and files and work as if they were on their computer. Many businesses have benefited from the increased use of telecommuting. It has also helped to cut down on unneeded costs. Productivity Gains Developers can access efficiently and successfully from any location that is convenient for them. As a result, their productivity improves. Researching Ease 152 CU IDOL SELF LEARNING MATERIAL (SLM)

Users no longer have to go out into the field to gather facts and submit them back into the system, making research easier. It's also made it much easier for field officers and academics to collect and input data from wherever they are, eliminating the need for wasteful travels to and from the office. Entertainment Mobile computing allows users to broadcast video and audio recordings on the go. It's simple to find a large range of movies, instructive, and informational content. With the advancement and affordable availability of high-speed data connections, one can obtain all the pleasure they desire while browsing the internet for streamed data. On the internet, one can watch news, movies, and documentaries, as well as other forms of entertainment. This was not conceivable prior to the advent of mobile computing in the computer world. Business Process Streamlining Secure communications have made business procedures more accessible. When it comes to security, suitable procedures have been designed to ensure that the information that the services is authenticated and authorised. Some business tasks can be performed over secure connections, and information can be shared between business partners.Video and voice conferencing can be used for meetings, seminars, and other educational services. The amount of time and money spent on travel is also significantly decreased. 7.4 SECURITY ISSUES: As with any other technology, mobile computing does have its share of security challenges. It's difficult to keep track of correct usage due of its nomadic nature. Users may have varying intents when it comes to how they will use this permission. Hacking, industrial espionage, pirating, online fraud, and malicious damage are just a few of the issues that mobile computing has to deal with. Credential verification is another major issue in mobile computing. Because other users share usernames and passwords, security is jeopardised. Because this is such a sensitive topic, most businesses are hesitant to deploy mobile computing due to the risk of misrepresentation. Identity theft is a challenging problem to contain or eliminate. Hackers gaining illegal access to data is also a major issue. Outsiders gain access to companies' essential data, which is a key impediment to the rollout of mobile computing services. No firm wants to expose its knowledge to hackers and other invaders, who will then sell the sensitive data to competitors. It's also critical to take the required safeguards to prevent such risks from occurring. Among the measures are the following: • Recruiting qualified employees. 153 CU IDOL SELF LEARNING MATERIAL (SLM)

• Putting safety hardware and software in place • Users must be educated on appropriate mobile computing ethics. • Auditing and implementing appropriate, effective mobile computing policies • Enforcing appropriate permits and access rights These are just a few techniques to help a company that offers mobile computing avoid potential dangers. Because information is so important, all potential safeguards should be assessed and implemented. In the absence of such safeguards, exploits and other unknown dangers can infiltrate systems and do irreversible harm. These could be in the form of reputational or financial consequences. In such instances, it's incredibly easy for it to be misappropriated for a variety of unethical purposes. If these elements aren't addressed effectively, it could become a source of persistent danger. There are still a number of risks associated with deploying this technology. 7.5SUMMARY • Mobile computing is a technology which allows data, voice, and video to be transmitted wirelessly from a computer or other wireless equipped device without the need for a fixed physical link. • Mobile computing can be thought of as PCs on the go: a device/system pair that you are using to perform business at a location other than your office desktop computer. It could be a hotel room or a branch office, or it could be your own home office. • Your computing demands can range from a simple query or \"look-up\" feature on a handheld device to a portable office area with real-time communication with both the home office to a portable office system with real-time connection with the home office. • A field worker, for example, might collect data such as water or power usage or even the current inventory levels for a specific item using a handheld gadget. A plumber might utilise a handheld device to locate his or her next service stop after completing one work. • It's also feasible that your \"mobile\" employees aren't even leaving the building. When they are not at their workstations, so-called \"campus workers\" might utilise a notebook or tablet to continue working. They could be working in the lunchroom or taking notes in a meeting, for example. 7.6 KEYWORDS 154 CU IDOL SELF LEARNING MATERIAL (SLM)

• SMS-SMS was designed for phones and mobile phones that use the GSM (Global System for Mobile Communication). • Mobile Hardware-The term \"mobile hardware\" refers to mobile devices or identified having that can be utilised to receive or access mobility services. 7.7 LEARNING ACTIVITIES 1. What happens if you make a typing error while entering the HTTP request and have to use backspace to correct it? (Note, experience indicates that the response to backspace is different on different servers) ___________________________________________________________________________ ___________________________________________________________________________ 2. Peterson & Davie give the general form of an HTTP message and some examples of request messages. Using this information, request the index page for the host www.cs.hmc.edu. Verify that the server returns an HTML document, and then closes the connection (i.e., after displaying the text of the page, the telnet program exits.) ___________________________________________________________________________ ___________________________________________________________________________ 7.8UNIT END QUESTIONS A. Descriptive Questions Short Questions 1. Define mobile computing. 2. What are the three aspects of mobile computing? 3. Compare mobile and wired communication. 4. What is WLL? 5. Define SMS. Long Questions 1. Explain about mobile hardware. 2. Describe the applications of mobile computing. 3. Explain about CDMA. 4. Explain the major advantages of mobile computing. 5. Explain the security issues in mobile computing B. Multiple Choice Questions 1. _____ is a software that allows users to send information from one location to another without using a physical link 155 CU IDOL SELF LEARNING MATERIAL (SLM)

a. Mobile computing b. Computer system c. Resources d. Android app 2. A ____ media that can send and receive messages is integrated into the gadgets. a. Transmitter b. Receptor c. Sound d. Network 3. GSM was created utilising ____ a. ARP b. RARP c. TDMA d. CMA 4. Mobile computing allows users to _____t video and audio recordings on the go. a. Show cast b. Telecast c. Display d. Broadcast 5. Identity ____ is a challenging problem to contain or eliminate. a. Theft b. Radar c. Face d. Global Answers 156 CU IDOL SELF LEARNING MATERIAL (SLM)

1-a, 2-b, 3-c, 4-d, 5-a 7.9 REFERENCES Reference books • Behrouz A Forouzan, “Data Communications and Networking”, McGraw Hill. • Andrew S. Tanenbaum, “Computer Networks”, Pearson Education. • Subir Kumar Sarkar, T.G. Basavaraju, C. Puttaamadappa, “AdHoc Mobile Wireless Network: Principles, Protocols, and Applications, CRC Press. Textbook references • James F. Kurose, Keith W. Ross, “Computer Networking”, Pearson Education. • Michael A. Gallo, William M. Hancock, “Computer Communications and Networking Technologies”, CENGAGE Learning Websites: • https://www.techopedia.com/definition/10062/wireless-communications • https://www.computernetworkingnotes.com/ • https://www.guru99.com 157 CU IDOL SELF LEARNING MATERIAL (SLM)

UNIT 8-NETWORKS STRUCTURE 8.0 Learning Objectives 8.1 Introduction to Networks 8.2 Wireline Communication 8.3 Introduction to Wireless Communication 8.4 History of Wireless Communication 8.5 Advantages of Wireless Communication 8.6 Disadvantages of Wireless Communication 8.7 A Wireless Communication System's Basic Elements 8.8 Types of Wireless Communication System 8.9 Adhoc Networks 8.10 Summary 8.11 Keywords 8.12 Learning activity 8.13 Unit End Questions 8.14References 8.0 LEARNING OBJECTIVES After studying this unit, you will be able to: • Understand the basics of wireless communication • Describe the advantages of wireless communication • Explain the types of wireless communication 8.1 INTRODUCTION TO NETWORKS We've arrived at a vital juncture in the evolution of technology's potential to extend and enhance human ability to communicate. The Internet's globalisation has happened quicker than anyone had predicted. To stay up with the expansion of this global network, the way people connect socially, commercially, politically, and personally is constantly changing. Innovators will be using the Internet as just a preliminary step for their efforts in generating new products in next stage of human evolution and services that are tailored to make the most 158 CU IDOL SELF LEARNING MATERIAL (SLM)

of the network's capabilities. As Developers test the boundaries of what is conceivable, as well as the interconnected system's capabilities. The Internet's networks will play an increasingly important role in their success. This chapter contains the data network platform on which both social and professional lives are built. Business partnerships are becoming increasingly reliant. The content builds the foundation for future learning. Network professionals face a variety of services, technologies, and difficulties when they design, build, and operate modern networks. 8.2 WIRELINE COMMUNICATION The transfer of data over a physical filament is known as wireline communication (also referred as wired communication). Wireless communication methods, on the other hand, send information over-the-air (OTA). Landline phones, televisions, and desktop PCs that link to the internet over Ethernet are all examples of wireline communication. Fibre optic, coaxial, and twisted pair is the three main types of wireline communication. Fibre optic - filament is made up about one or even more optical fibres, each of which can transport light-wave modulated signals. Fibre optic cable is divided into two types: single- mode and multi-mode. For larger distances, single-mode fibre is employed, with a laser as the light source. For shorter distances, multi-mode fibre is employed, and the light source is usually a light emitting diode (LED). Filament coaxial cable is made out of copper cable with such a metal shield as well as other components designed to prevent signal interference. Cable TV companies use coaxial cable that connects their satellite antenna installations to their customers' homes and businesses. Telephones companies also utilise it to connect strengthen cooperation to telephone poles near clients. Wrapped pair - filament is made up of 2 insulated copper wires twisted around one another to prevent crosstalk and electromagnetic induction. Although twisted pair is commonly associated with domestic use, because it is less expensive than coaxial cable, it is frequently seen in horizontal wiring in local area network (LAN) deployments. Twisted pair is wrapped in a shield that serves as a ground in some business places. Shielded twisted pair is the technical term for this (STP). Unshielded twisted pair wire is used to connect the house to the rest of the world (UTP). NBASE-T Ethernet is also an IEEE standard with Ethernet- signalling technology that enables existing twisted-pair copper cabling to transmit data at speeds greater than 1 Gbps over distances up to 100 metres. (For more information, see Twisted Pair Cable Types.) 159 CU IDOL SELF LEARNING MATERIAL (SLM)

Technically, all wireless communication can be considered wireline communication because actual cables will be utilised to record wireless signals at some point in the communication chain. 8.3 INTRODUCTION TO WIRELESS COMMUNICATION Wireless communication is one of the most rapidly evolving and dynamic technology areas in the realm of communication. Wireless media is a type of sending data from one location to another without the use of wires, cables, or any other physical medium. Via general, information is conveyed from a transmitter to a receiver across a short distance in a communication system. The transmitter and receiver could be located anywhere between a few metres (like a television remote control) and a few thousand kilometres with the use of wireless communication (Satellite Communication). We live in a society of communication, and wireless communication in particular plays an important role in our daily lives. Mobile phones, GPS receivers, remote controls, Bluetooth audio, and Wi-Fi are some of the most regularly utilised Wireless Communication Systems in our daily lives. What are Wireless Communication and How Does It Work? Wired or wireless communication systems are available, as well as guided and unguided communication mediums. The medium in Wired Communication is a physical path, such as Co-axial Cables, Twisted Pair Cables, and Optical Fibre Links, that leads the signal from one point to another. The term \"guided medium\" refers to this type of medium. Wireless communication, on the other hand, does not require a physical channel and instead sends the signal via space. The medium utilised in Wireless Communication is known as Unguided Medium since space simply allows the signal transmission without any guiding. Figure 8.1 Electro Magnetic Wave Communication 160 CU IDOL SELF LEARNING MATERIAL (SLM)

How does wireless communication carry signals if there is no physical medium? Antennas are utilised to transmit and receive signals in wireless communication, even though there are no cables involved. Antennas are electrical devices that convert electrical signals into radio signals via Electromagnetic (EM) waves and vice versa. Electromagnetic waves are waves that travel through space. As a result, an antenna is used by both the transmitter and the receiver. What is an Electromagnetic Wave, and how does it work? The electromagnetic energy of an electromagnetic field is carried over space by electromagnetic waves. Gamma Rays (– Rays), X – Rays, Ultraviolet Rays, Visible Light, Infrared Rays, Microwave Rays, and Radio Waves are all examples of electromagnetic waves. Electromagnetic waves (typically Radio Waves) are used to transport signals in wireless communication. In the form of time-varying sinusoidal waves, an Electromagnetic Wave comprises from both electric and magnetic fields. Both of these fields oscillate perpendicularly to one another, or the direction of propagation of the Electromagnetic Wave is perpendicular to both of them. Maxwell's equations can be used to mathematically describe an Electromagnetic Wave. An Electromagnetic Wave is depicted in the diagram below, with the Electric Field operating on the Y axis, the Magnetic Field acting on the Z axis, and the Electromagnetic Wave propagating on the X axis. 8.4 HISTORY OF WIRELESS COMMUNICATION Wireless communication has been a feature of human life while the use of smoke signals, flags, and flashing mirrors in the prehistoric period, and it is constantly evolving. Wireless communication, or the use of electrical signals and radio waves for communication, has been around for over a century. Guglielmo Marconi demonstrated wireless telegraphy in 1897 by transmitting EM waves over a small distance of 100 metres. This demonstration cleared the door for radio communication, which is derived from the phrase \"radiant energy.\" Trans-Atlantic radio transmission had been developed by the early 1900s, with Marconi successfully transmitting Morse code communications. Since then, wireless communication and system technology has improved significantly, allowing transmissions across longer distances at lower costs and with fewer expensive devices. Many wireless technologies and methods have blossomed and many have vanished during the growth of technologies communication. Telephone communication or television transmission is the best examples of this. All telephone-related communication was (and still is) carried out over a wired network, which we refer to as Landline Telephone. 161 CU IDOL SELF LEARNING MATERIAL (SLM)

However, as mobile communication grew in popularity, it began to supplant the cumbersome conventional telephone system. In this scenario, wired technology has become obsolete, and wireless communication has taken its place. Television transmission is another example of where wireless communication has been superseded by wired connection. Wireless radio transmitters were used to broadcast television signals in the early days. However, cable television has since supplanted this configuration. These two instances demonstrate that, as technology advances, we must always choose what is appropriate for the situation, i.e., in certain cases, wired connection is required, whilst in others, wireless communication may be a superior alternative. Why is Wireless Communication Necessary? Why do we need wireless communication when wired communication can perform most of the functions that wireless communication can? Mobility is the fundamental and most crucial benefit of wireless communication. Wireless communication, in addition to mobility, provides flexibility and convenience of use, making it increasingly popular day by day. Wireless communication, such as mobile telephone, can be done anywhere, at any time, and with a very high throughput. Infrastructure is another crucial consideration. Infrastructure development and installation for wired communication systems is just an expensive and time-consuming task. Wireless communication infrastructure is simple and inexpensive to set up. Wireless communication is a potential solution in real emergencies and remote regions where wired connection is difficult to set up. 8.5 ADVANTAGES OF WIRELESS COMMUNICATION: Wireless Communication Technology, Wireless Networking, and Wireless Systems have various advantages over wired communication, including cost, mobility, ease of installation, and reliability. Cost Wireless communication eliminates the cost of establishing wires, cables, and other infrastructure, lowering the overall power consumption when compared to wired communication. Installing a wired network in a building, digging into the ground to lay cables, and connecting those wires over streets is a complex, expensive, and time-consuming task. Drilling holes for cables in historical buildings is not a good idea because it compromises the structure's integrity and significance. Wireless connection, such as Wi-Fi or Wireless LAN, is also the only option in older buildings without dedicated lines for communication. 162 CU IDOL SELF LEARNING MATERIAL (SLM)

Mobility As previously said, the fundamental benefit of a wireless communication system is mobility. It allows you to walk about while being connected to the network. Installation Procedural Ease The technology and architecture of a wireless communication network are very simple to set up and deploy because there are no cables to deal with. In addition, setting up a wireless system, such as a Wi-Fi network, takes much less time than setting up the entire cabled network. Reliability Because wireless communication does not employ cables or wires, there is no risk of system failures due to cable damage, which could be affected by natural factors, cable splices, or natural deterioration of metallic conductors. Recovering from a disaster The loss of communications networks in a wireless communication can be low in the event of an accident caused by fire, floods, or other disasters. 8.6 DISADVANTAGES OF WIRELESS COMMUNICATION: Wireless communication has a lot of advantages over conventional communication, but it also has a few drawbacks. Interference, security, and health are the most serious drawbacks. Wireless communication systems that use free space as a medium for signal transmission are known as interference wireless communication systems. As a result, there's a good risk that radio signals through one wireless communication system and network will interfere with signals from other wireless communication systems or networks. Bluetooth and Wi-Fi are the finest examples (WLAN). Each of these technologies uses the 2.4GHz band for communication, and there is a potential of interference if both of these devices are operational at the same time. Security The security of data is one of the primary concerns of wireless communication. Because the signals are broadcast in open space, an intruder may be able to intercept them and copy important information. Health Issues Continuous exposure to radiation of any kind can be dangerous. Even though the exact quantities of RF energy that really can cause damage have yet to be determined, it is recommended that RF radiation be avoided to the greatest extent possible. 163 CU IDOL SELF LEARNING MATERIAL (SLM)

8.7 A WIRELESS COMMUNICATION SYSTEM'S BASIC ELEMENTS The Transmitter, Channel, and Receiver are the three main components of a conventional Wireless Communication System. The block diagram of a wireless communication system is shown in the image below. Figure 8.2 Elements of Wireless Communication The Transmission Path Encoder, Encryption, Modulation, and Multiplexing are all common components of the wireless communication system's transmission path. The signal first from source is sent through a Source Encoder that turns it into a format that can be processed with signal processing techniques. This procedure removes duplicate information from signals in order to maximise resource use. This signal would then be encrypted to use an Encryption Standard to ensure that the signal and data are secure and that no unauthorised access is possible. Channel encoding is a signal processing technique that reduces signal flaws such as noise and interference. A little level of redundancy is injected to the signal during this procedure, making it more resilient against noise. The signal is then modulated with an appropriate modulation technique (such as PSK, FSK, or QPSK, for example) so that it may be easily broadcast using an antenna. To share the valuable bandwidth, the modulated signal is multiplexed with certain other signals using different Multiplexing Techniques such as Time Division Multiplexing (TDM) and Frequency Division Multiplexing (FDM). The English Channel 164 CU IDOL SELF LEARNING MATERIAL (SLM)

In Wireless Communication, the channel denotes the signal's transmission medium, which is open space. The nature of a wireless channel is unpredictable, as well as very varied and random. Interference, distortion, noise, dispersion, and other factors can cause a channel's received signal to be packed with mistakes. The Path to Reception The Receiver's role is to collect the channel's signal and reproduce this as source signal. Demultiplexing, Demodulation, Channel Decoding, Decryption, and Source Decoding are all part of a Wireless Communication System's reception path. The receiver's role is clearly inverse to that of the transmitter, as evidenced by the elements of the reception path. The Demultiplexer receives the channel's signal and separates it from other transmissions. Individual signals are demodulated and the original message signal is retrieved using appropriate Demodulation Techniques. The Channel Decoder is used to remove the unnecessary bits from the message. Decryption of the signal eliminates the security and converts it into a simple sequence of bits because the message is encrypted. Finally, the Source Decoder receives this signal in order to recover the original delivered message or signal. 8.8 AD HOC NETWORKS A centrally controlled network is not always required to connect two machines. Users can instead create an ad hoc network between two machines. A wireless network that dynamically connects wireless client devices to one another without the usage of infrastructure equipment like access points or base stations. Without the use of a wireless router or access point, ad hoc networks are formed by connecting two or more wireless PCs together. The computers communicate with one another immediately. Ad hoc networks can be extremely useful during meetings or in any other situation when individuals need to share files but don't have access to a network.These networks are classified as mobile ad hoc networks (MANET); wireless sensor networks (WSN), wireless mesh networks (WMN), and vehicular ad hoc networks based on their applications (VANET). A decentralised wireless network is known as a wireless ad hoc network (WANET) or a mobile ad hoc network (MANET). Ad hoc is a communication mode (setting) in the Windows operating system that allows machines to connect directly with each other without the use of a router. The army will be able to maintain a network among all of the soldiers, vehicles, and headquarters thanks to ad hoc networking. Traditional networks are slower than ad-hoc networks. They are typically less secure due to the widespread use of wireless connections (which are less secure than cable connections) and the lack of a central device to manage network security. 165 CU IDOL SELF LEARNING MATERIAL (SLM)

8.9 TYPES OF WIRELESS COMMUNICATION SYSTEM People nowadays use mobile phones for a variety of purposes, including communicating, surfing the internet, and viewing multimedia. All of these services must be available to users on the go, that is, while they are on their mobile devices. We can transfer speech, data, videos, and photos via these wireless communication technologies. Video conferencing, cellular telephone, paging, TV, radio, and other services are all available through wireless communication systems. Various sorts of Wireless Communication Systems have been developed in response to the requirement for a variety of communication services. The following are some of the most important Wireless Communication Systems on the market today: • Broadcasting on television and radio • Radar Satellite Communication System for Mobile Phones (Cellular Communication) • The GPS (Global Positioning System) is a satellite navigation system that (GPS) • Communication using Infrared • WIFI (Wi-Fi) • Paging Cordless Phones with Bluetooth Zigbee • Identification via Radio Frequency (RFID) There are other additional systems, each with its own set of uses. Simplex, Half Duplex, and Full Duplex are the three types of wireless communication technologies. One-way communication is known as simplex communication. The radio broadcasting system is an example. Half-duplex communication is two-way but not simultaneous. Walkie-talkie is an example (civilian band radio). Full Duplex communication is also two-way, but it is done at the same time. Mobile phones are the best illustration of complete duplex. Wireless communication devices vary in size, form, data transmission, and cost from one provider to the next. A Wireless Communication system's coverage area is also a significant consideration. Wireless networks can encompass a single building, an entire corporate campus, a city, a small regional area (larger than a metropolis), or the entire world. We'll take a look at a few of the most essential Wireless Communication Systems. Broadcasting on television and radio Radio is thought to be the very first wireless service broadcast. It was an example of a Simplex Communication System, in which data is only sent in one direction and all users receive the same information. 166 CU IDOL SELF LEARNING MATERIAL (SLM)

Figure 8.3 Wireless Broadcast Communication by satellite A satellite communications network is just a sort of wireless communication that is widely used. Satellite Communication Networks offer coverage that is independent of population density around the world. Satellite Communication Systems provide services such as telecommunication (Satellite Phones), position and navigation (GPS), broadcasting, and the internet, among others. Satellite Communication Systems are also used by other wireless services such as mobile phones, television transmission, and other radio systems. Communication System for Mobile Phones 167 CU IDOL SELF LEARNING MATERIAL (SLM)

Mobile Phone Technology is perhaps the most widely used wireless communication system. Like no other technology, the generation of digital cellular devices transformed the world. Today's smartphones include a variety of functions such as Bluetooth, WI-Fi, GPS, and FM radio in addition to the ability to make calls. The 5G generation of mobile communication technology is the most recent (which is indeed successor to the widely adapted 4G). 5G Networks are focused towards Internet of Things (IoT) related applications including future autos, in addition to enhanced data transfer rates (technologists claim transmission rates in the order of Gbps). The GPS (Global Positioning System) The Global Positioning System (GPS) is a subgenre of satellite communication. With the use of dedicated GPS receivers and satellites, GPS delivers various wireless services such as navigation, positioning, location, speed, and so on. Bluetooth Paging Although it is now regarded antiquated, paging was a huge success prior to the widespread adoption of mobile phones. Paging is a simplex system in which the user could only receive messages and gives data in the form of messages. Another notable low-range wireless communication method is Bluetooth. It has a transmission range of 10 metres and can transmit data, voice, and audio. Bluetooth devices are found in almost most mobile phones, tablets, and laptops. Wireless Bluetooth receivers, audio equipment, cameras, and other devices can all be attached to them. Local Area Network WLAN (Wireless Local Area Network) is an internet-connected wireless service. WLAN allows various devices, such as laptops and smartphones, to link to an access point (such as a Wi-Fi Router) and connect to the internet. Wi-Fi is a commonly utilised wireless network that is typically used for internet access (but sometimes for data transfer within the Local Area Network). It's tough to picture a world without Wi-Fi in today's world. Communication using Infrared Infrared communication is yet another type of wireless communication that we utilise on a regular basis. It makes use of the Electromagnetic (EM) spectrum's infrared wavelengths. Infrared (IR) communication are utilised in television remote controls, automobiles, and audio equipment, among other things. 8.10SUMMARY 168 CU IDOL SELF LEARNING MATERIAL (SLM)

• The transfer of data over a physical filament is known as wireline communication (also referred as wired communication). Wireless communication methods, on the other hand, send information over-the-air (OTA). • Landline phones, televisions, and desktop PCs that link to the internet over Ethernet are all examples of wireline communication. • Fibre optic, coaxial, and twisted pair is the three main types of wireline communication. • The transfer of data more than a wire-based communication method is referred to as wired communication. Wireline communication is another name for wired communication. Telephone networks, cable television and internet access, &fibre- optic communication are all examples. • Ethernet cables are used to carry data between connected PCs in most wired networks. Wired line also includes waveguide (electromagnetism), which is utilised for high- power applications. • Local telephone networks, which are used by either residential and business users in the area, are frequently employed as the foundation for wired communications. • Many networks currently rely on fibre optic communication technology to provide unambiguous signalling for both inbound and outgoing communications, and copper wire transmission is being phased out. Fibre optic technology can accommodate significantly more signals that copper wiring while retaining signal integrity over far longer distances. 8.11 KEYWORDS • Television transmission- Television transmission is another example of where wireless communication has been superseded by wired connection. • Fibre optic - Filament is made up about one or even more optical fibres, each of which can transport light-wave modulated signals 8.12LEARNING ACTIVITY 1. Can you analyse, what are the possible applications for Machine Learning on Optical Wireless Communication? ___________________________________________________________________________ ___________________________________________________________________________ 2. If you are a network administrator and you are about to set a network connection for your organization using wireless communication, draw the architecture for the same. 169 CU IDOL SELF LEARNING MATERIAL (SLM)

___________________________________________________________________________ ___________________________________________________________________________ 8.13UNIT END QUESTIONS A. Descriptive Questions Short Questions 1. Write any two examples of wireline communication. 2. What is OTA? 3 Define guided medium. 4. What are the basic elements of wireless communication? 5. Write the advantages of wireless communication. Long Questions 1. How does wireless communication works? 2. How does wireless communication carry signals if there is no physical medium? 3. What is an Electromagnetic Wave, and how does it work? 4. Why is Wireless Communication Necessary? 5. Explain the disadvantages of wireless communication. B. Multiple Choice Questions 1. ______ filament is made up about one or even more optical fibres. a. Fibre optic b. Coaxial c. Twisted pair d. Light 2. Wired or wireless communication systems are _____ and _____ communication mediums. a. Cable and non-cable b. static and dynamic c. guided and unguided d. Physical and logical 170 CU IDOL SELF LEARNING MATERIAL (SLM)

3. Electromagnetic waves are waves that travel through ____. a. air b. bus c. cable d. space 4. Maxwell's equations can be used to mathematically describe an___ a. Electromagnetic wave b. Electrical signals c. Incident ray d. Instance 5. Bluetooth and Wi-Fi are the finest examples of ___ a. LAN b. MAN c. WLAN d. WMAN Answers: 1-a, 2-c, 3-d, 4- a, 5- c 8.14REFERENCES Reference books • Behrouz A Forouzan, “Data Communications and Networking”, McGraw Hill. • Andrew S. Tanenbaum, “Computer Networks”, Pearson Education. • Subir Kumar Sarkar, T.G. Basavaraju, C. Puttaamadappa, “AdHoc Mobile Wireless Network: Principles, Protocols, and Applications, CRC Press. Textbook references • James F. Kurose, Keith W. Ross, “Computer Networking”, Pearson Education. • Michael A. Gallo, William M. Hancock, “Computer Communications and Networking Technologies”, CENGAGE Learning 171 CU IDOL SELF LEARNING MATERIAL (SLM)

Websites: • https://en.wikipedia.org/wiki/Mobile_computing • https://www.computernetworkingnotes.com/ • https://www.guru99.com 172 CU IDOL SELF LEARNING MATERIAL (SLM)

UNIT 9-ARCHITECTURE OF MOBILE COMPUTING STRUCTURE 9.0 Learning Objectives 9.1 Introduction to Mobile Computing 9.2 Development for N-Tier Architecture 9.3 Advantages of a three-tier architecture 9.4 Summary 9.5 Keywords 9.6 Learning activity 9.7 Unit End Questions 9.8 References 9.0 LEARNING OBJECTIVES After studying this unit, you will be able to: • Define the basics of Mobile Computing • Elaborate the development for N-Tier Architecture • Study the types of N-Tier architecture • Definethe advantages of 3-Tier architecture 9.1INTRODUCTION TO MOBILE COMPUTING The fundamental and intermediate principles of mobile computing are covered in this tutorial. This tutorial will give an overview on Mobile Computing, its ongoing evolution, and the technology's future tendencies. Our Mobile Computing lesson is appropriate for both beginners and experts. The term \"mobile computing\" refers to a technology which allows data, speech, and video to be transmitted wirelessly from a computer device. It does not rely on a fixed physical link for connectivity. It allows users to transition through one physical location to the other while communicating. Our mobile communication course covers all aspects of mobile computing, including a brief review and history, evolution, classification, benefits and drawbacks, security concerns, and future trends. 173 CU IDOL SELF LEARNING MATERIAL (SLM)

Mobile computing is software that allows users to send information from one location to another without using a physical link or cords. In other words, mobile computing allows data, voice, and video to be transmitted from a computer or any other WIFI connection without the need for a fixed physical link. Data is transmitted wirelessly via wireless devices such as smartphones and laptop computers in this technology. This is only possible because to Mobile Computing technology, which allows you to view and transmit data from every remote location without physically being present. Mobile computer technology allows for a wide range of communication coverage. It is one of the most reliable and fastest-growing areas of computing technology. The specification of numerous levels between data access interfaces, devices, and network hardware is referred to as mobile computing architecture. For systematic calculations including accessibility to data and software objects, a well-defined architecture is required. Wireless transmission is often associated with mobile computing; however mobile computing is not always associated with wireless transmission. Some of the characteristics are followed by mobile computing. The presentation tier, or interface; the application tier, in which data is processed; and the data tier, where another data associated with the application is stored and managed, is a well- established software application architecture which organises applications into multiple logical and physical computing tiers. A three-tier architecture is a client-server design where the functional process logic, data access, computer data storage, and user interface are all built and maintained separately on different platforms. Three-tier architecture is well-known software architecture and a software design pattern. Any one of the three layers can be upgraded and replaced individually in a three-tier design. The user interface is available as a native programme, web app, mobile app, voice interface, and more on any platform, including a desktop PC, smartphone, or tablet. It has a typical graphical user interface, and the application server runs many modules. The computer storage logic is stored in the relational database upon the database server. Multitiered middle layers are common. Because the three are conceptual rather than physical, they can run on various servers in both on-premises and software-as-a-service solutions (SaaS). 174 CU IDOL SELF LEARNING MATERIAL (SLM)

Fig 9.1 Network Layer While the entire system continues to evolve naturally, key elements of the application could be encapsulated and retained.The development cycle and upgrade periods are greatly reduced, resulting in minimum disturbance to the customer's experience. Separate teams can focus on multiple pieces of the application instead of the entire stack, increasing efficiency and speed.Because each tier runs by its own infrastructure, three-tier architecture has the advantage of allowing each tier to be built concurrently by a distinct development team and upgraded or scaled when needed without affecting the other tiers. Three-tier architecture is just an application programme that is divided into three major sections: • At the bottom of the data access layer tier, • The middle tier (business logic) and the application tier • The top tieris the client tier (presentation). Each layer is distributed across a network to a different location or locations. These tiers don't always correspond to actual locations on different computers on a network, but also to the application's logical levels. 175 CU IDOL SELF LEARNING MATERIAL (SLM)

Fig 9.2 Three -Tier Architecture 1. User Interface (UI) Layer: This layer displays information to the database and may allow data editing and entry. It also requests data from the Business layer. Dynamic HTML with client-side data sources including data cursors were used to create this layer. The presentation tier was its application's user interface or communication layer, which is where the end consumer interacts with it. Its primary function is to present information to and gather data from the user. This top-level tier, for example, can be accessed via a web browser, a desktop programme, or a graphical user interface (GUI). HTML, CSS, and JavaScript are commonly used to create web presentation levels. Depending on the platform, desktop apps can be built in a variety of languages. In the form of a graphical user interface, occupies the top level that displays information relating to services usually available on a web browser or web-based application (GUI). It is the application's front-end layer and the interface with and which end-users would interact directly. 176 CU IDOL SELF LEARNING MATERIAL (SLM)

This layer connects with other tiers by transmitting results towards the browser and other layers in the network via API calls. It is typically built upon web development frameworks like CSS or JavaScript. 2. Application Tier This tier is derived from the presentation tier and is also known also as middle tier, logic tier, business rules, or logic tier. It performs sophisticated processing to govern the application's essential functioning and is typically written in programming languages such as Python, Java, C++, .NET, and others. The heart of the application is the application tier, often known as that of the logic tier or middle tier. Information from the presentation layer is handled at this tier, sometimes in conjunction with data from the data tier, using business logic, or a set of business rules. The data tier can also be added to, deleted from, or modified by the application tier. The application tier connects with the data tier via API calls and is often written in Python, Java, Perl, PHP, or Ruby. Client queries from workstations are sent to the business logic, which functions as a server. It acts in accordance with business rules, retrieving or inserting data via the Data Layer. As a result, it determines what data is required (and where it may be found) and operates as a client in relation to third-tier programming on a local and mainframe computer. Since these middle-tier components aren't connected to a particular individual, they can be used by any application and relocated as needed to meet reaction time and other requirements. 177 CU IDOL SELF LEARNING MATERIAL (SLM)

Fig 9.3 Three Layers of architecture This tier is derived from the presentation tier and is also known also as middle tier, logic tier, business logic, or logic tier. It performs sophisticated processing to govern the application's essential functioning and is typically written in programming languages such as Python, Java, C++, .NET, and others. The heart of the application is the application tier, often known also as logic tier or middle tier. Information from the presentation layer is handled at this tier, sometimes in conjunction with data from the data tier, using business logic, or a set of business rules. The data tier can also be added to, deleted from, or modified by the application tier. The application tier connects with the data tier via API calls and is often written in Python, Java, Perl, PHP, or Ruby. Client queries from workstations are sent to the business logic, which functions as a server. It acts in accordance with business rules, retrieving or inserting data via the Data Layer. As a result, it determines what data is required (and where it may be found) and operates as a client in relation to third-tier programming on a local or mainframe computer. Since these middle-tier components aren't connected to a specific client, they could be used by any application and relocated as needed to meet reaction time and other requirements. 3. Data Tier The DBMS, which provides all of the data for the first two tiers, makes up the third level of the 3-tier system. This is the DBMS's actual access layer. Database servers are located here, and they are where data is stored or retrieved. Data in this tier is handled and accessible using programmes like MongoDB, Oracle, MySQL, and Microsoft SQL Server, and is kept separate from application servers and business logic. Because there are no dependencies on storage methods, upgrades or changes can be made without affecting or even notifying the application tier customers. The data tier, also known as the database tier, data access tier, or back-end, is where the application's data is kept and maintained. A relational database management system, like PostgreSQL, MySQL, MariaDB, Oracle, DB2, Informix, or Microsoft SQL Server, or a NoSQL database server, such as Cassandra, CouchDB, or MongoDB, can be used. All communication in a three-tier application goes through the application tier. The data tier and the presentation tier are unable to interact with one another. 9.2DEVELOPMENT FOR N-TIER ARCHITECTURE 178 CU IDOL SELF LEARNING MATERIAL (SLM)

Because software professionals need complete control over all layers of both the architecture, the following n-tier architecture tips are provided. Using an approach like soap XML, try to disconnect layers from one another as much as feasible.Create a mapping here between business logic layer as well as a relational database layer using automated tools (data layer). Entity Framework and Hibernate for.Net are two tools that can assist in modelling these mapping strategies. Put as much common code for all clients as feasible in a separate library in the client presenter layer. This will increase the code's reusability for various clients. To improve performance, a cache layer might be added to an existing layer. 9.3 ADVANTAGES OF A THREE-TIER ARCHITECTURE The main advantage of three-tier architecture is the physical and logical separation of functions. Each tier can run on the operating system & server platform that best suits its functional requirements, such as a web server, application server, or database server. Each tier also runs on its own dedicated server hardware and virtual server, allowing each layer's services to be changed and optimised without affecting the other tiers. It gives development teams a lot of flexibility because they may update or change only specific elements of the application and affecting the entire product. The programme may be easily scaled up and down by divorcing the front-end application from either the databases that are chosen based on the customer's specific needs. To deal with enormous amounts of data or highly demanding services, extra hardware, including such new servers, can be added later.A three-tier design also gives businesses more flexibility when it comes to implementing new technology as soon as it arrives. Other advantages over single-tier or two-tier architecture include: Faster development: Because each layer may be built concurrently by multiple teams, a company can get an app to market faster, while programmers can use the most up-to-date languages and tools by each tier. Improved scalability: Each layer can be scaled separately as needed. Improved resiliency: A failure in one layer is less likely to affect the availability and performance of the others. Because the presentation and data tiers cannot connect directly, a very well application tier can act as an internal firewall, preventing SQL injections as well as other dangerous vulnerabilities. In web development, a three-tier application is used. The layers in web development have multiple words but fulfil the same functions: 179 CU IDOL SELF LEARNING MATERIAL (SLM)

The user interface is provided by the web server, which is the presentation tier. This is frequently a web page or web site, including an ecommerce site, where the user places items in their shopping basket, enters payment information, or opens an account. HTML, CSS, and JavaScript are commonly used to create static and dynamic content. The application server, which is part of the middle tier, is where the business logic for processing user inputs is stored. This is the layer that, in the ecommerce example, queries an inventory database to retrieve product availability or adds information to a customer's profile. This layer is usually written in Python, Ruby, or PHP and supports a framework like Django, Rails, Symphony, or ASP.NET. A web application's data and backend tier is the database server. It's powered by database management systems like MySQL, Oracle, DB2, and PostgreSQL. 9.4SUMMARY • The specification of numerous levels between application-level interfaces, devices, & network hardware is referred to as mobile computing architecture. • For systematic calculations including access to technology and application objects, a well-defined architecture is required. • Wireless transmission is often associated with mobile computing; however mobile computing is not always associated with wireless transmission. Some of the characteristics are followed by mobile computing. • Mobile computing is a type of human–computer interaction where a computer is supposed to be transported throughout normal use, allowing data, speech, and video to be transmitted. Mobile computing is made up of three components: mobile communications, mobile hardware, & mobile software. • Ad hoc and infrastructure networks, as well as communication features, protocols, data formats, and concrete technologies, are all examples of communication challenges. Mobile devices and device components are examples of hardware. • The characteristics & requirements of mobile apps are addressed by mobile software. 9.5 KEYWORD • Presentation Layer (UI)- This layer presents data to the user and optionally permits data manipulation and data entry, also this layer requests the data form Business layer • Application Layer (AL)-The business logic acts as the server for client requests from workstations. It acts according Business rules fetch or inserts data through the Data Layer. 180 CU IDOL SELF LEARNING MATERIAL (SLM)

• Data Access Layer (DA)-The third tier of the 3-tier system is made up of the DBMS that provides all the data for the above two layers. 9.6 LEARNING ACTIVITY 1.Consider the software professionals must have a full control on all the layers of the architecture, tips on n-tier architecture are given as below i. Try to decouple layers from another layer as much as possible by using a technique like soap XML. ii. Use some automated tools to generate a mapping between a business logic layer and a relational database layer (data layer). Tools that can help in modelling these mapping techniques are – Entity Framework and Hibernate for .Net etc. ___________________________________________________________________________ ___________________________________________________________________________ 2.Do the following: i. In client presenter layer, put a common code for all the clients in a separate library as much as possible. This will maximize the code reusability for all types of clients. ii. A cache layer can be added into an existing layer to speed up the performance. ___________________________________________________________________________ ___________________________________________________________________________ 9.7 UNITEND QUESTIONS A. Descriptive Questions Short Questions 1. Define Mobile computing? 2. What is Application layer? 3. Write any two advantages of 3-tier architecture. 4. What is presentation layer? 5. Write the benefits of data tier. Long Questions 1. Explain the development of n-tier architecture. 2. Explain the working of Mobile computing architecture. 3. Discuss about the 3 tiers of mobile architecture. 4. Explain about Three-tier application in web development 181 CU IDOL SELF LEARNING MATERIAL (SLM)

5. Explain advantages of 3-tier architecture. B. Multiple Choice Questions 1. Which is a markup language that is commonly used to create web pages? a. HTTP b. MDP c. TCP d. HCP 2. ___ can also be used to download files from other servers to a PC. a. TCP b. FTP c. FDP d. RCP 3. ___ is a directory service which maps a host's name to its numerical address on a network. a. WWW b. source c. DNS d. FTP 4. Who established the World Wide Web? a. Luther King b. Barris Boem c. Karl Klinton d. Tim Berners Lee 5. A Uniform Resource Locator (URL) is ____ address given to a web page 182 a. Remote b. Local c. Internet CU IDOL SELF LEARNING MATERIAL (SLM)

d. Common Answers: 1-a, 2- b, 3- c, 4- d, 5-c 9.8REFERENCES Reference books • Behrouz A Forouzan, “Data Communications and Networking”, McGraw Hill. • Andrew S. Tanenbaum, “Computer Networks”, Pearson Education. • Subir Kumar Sarkar, T.G. Basavaraju, C. Puttaamadappa, “AdHoc Mobile Wireless Network: Principles, Protocols, and Applications, CRC Press. Textbook references • James F. Kurose, Keith W. Ross, “Computer Networking”, Pearson Education. • Michael A. Gallo, William M. Hancock, “Computer Communications and NetworkingTechnologies”, CENGAGE Learning Websites: • https://en.wikipedia.org/wiki/Mobile_computing • https://www.computernetworkingnotes.com/ • https://www.guru99.com 183 CU IDOL SELF LEARNING MATERIAL (SLM)

UNIT 10-INTRODUCTION TO WIRELESS COMMUNICATION SYSTEM 1 STRUCTURE 10.0 Learning Objectives 10.1 Introduction to Wireless Communication System 10.2 Wireless Communication Fundamentals 10.3 Radio Frequency 10.4 Comparison of Common wireless system 10.5 2G 10.6 3G 10.7 4G 10.8 Wireless LAN: An Overview 10.9 Wi-Fi 10.10 Wi-Max 10.11 Summary 10.12 Keywords 10.13 Learning Activity 10.14 Unit End Questions 10.15 References 10.0LEARNING OBJECTIVES After studying this unit, you will be able to: • Study the basics of Wireless Communication System • Learn about Radio Frequency • Study the comparison wireless system • List the advantages 2G, 3G, and 4G • Explain about Wi-fi and Wi-max 10.1INTRODUCTION TO WIRELESS COMMUNICATION SYSTEM 184 CU IDOL SELF LEARNING MATERIAL (SLM)

We must first discuss the wired medium before moving on to the wireless medium. A bounded medium is a wired network. Data travels along the course of a wire or cable. The wired channel of communication imposes the restriction on user's interaction in the present era of technology and vast numbers of gadgets. Wired networks have a number of drawbacks. Consider the following scenario: you wish to connect to ten or more devices in your immediate vicinity. You'll need the same number of ports to connect to devices, but a high number of ports may seem impractical, but it's not impossible with a wireless network. Wireless networks, as their name implies, do away with the necessity for wires or cables. Its key characteristics are convenience and mobility. Several different wireless devices may readily and smoothly join to the network. Because wireless data travels via the air, there has to be some limitations to wireless communication. These are the following: • Most wireless devices must adhere to the IEEE 802.11 standard. • Wherever devices are expected to be used, wireless coverage should be available. 10.2 WIRELESS COMMUNICATION FUNDAMENTALS Through RF (radio frequency), wireless communicating over open space, with one device, the Transmitter, sending a signal to another device, the Receiver. To communicate with each other, two devices (transmitter and receiver) will be using the same frequency (or channel). Radio frequency interference can occur when a large number of network devices communicate at the same time. As the number of devices grows, so does the amount of interference. Fig 10.1 Unidirectional communication 185 CU IDOL SELF LEARNING MATERIAL (SLM)

Fig 10.2 Bidirectional Communication Fig 10.3 Interference from another device Wireless devices exchange airtime in the same way that wired devices share bandwidth and connect to shared media. To avoid colliding or interfering with other wireless devices, all wireless devices run in half duplex mode. Before transmitting, IEEE 802.11-compliant devices must verify that the channel was available and clear. Because transmission uses the same frequency or channel, wireless communication always is half duplex. To reach total duplex mode, devices use different transmission frequencies or channels. The reception of signals Wireless transmission is sometimes referred to as \"full- duplex,\" but it is not strictly true. 10.3RADIO FREQUENCY The sender (transmitter) sends an alternating current onto a segment of wire in free space (an antenna). This creates a moving electromagnetic field, which propagates as waves. As depicted, the electric and magnetic fields travel at a straight angle to each other. To keep the electric and magnetic fields cyclic and pushing forward, the signal must change or alternate by cycle up and down. The frequency of a wave is the number of cycles it completes in a second. So, Frequency = no of cycles per second 186 CU IDOL SELF LEARNING MATERIAL (SLM)

Fig 10.4 Radio Frequency The number of cycles per second is known as frequency. Waves of electricity do not move in a straight line. They move away from the antenna by extending in all directions. When you throw or toss a stone in a water body, you can observe waves travelling across the water. Fig 10.5 Wave propagation 10.4COMPARISON OF COMMON WIRELESS SYSTEM Mobile computing makes use of both fixed and wireless networks. To connect existing, wired communications systems, fixed networks frequently use radio transmission. Let's look at how wire and mobile networks differ in mobile computing. The distinction between fixed and wireless networks is that wireless networks do not require the use of wires to establish a physical connection with both the device. Since it is a shared medium, it is easily assessed. Fixed networks, on the other hand, necessitate a physical setup 187 CU IDOL SELF LEARNING MATERIAL (SLM)

of equipment in order to transmit data. Inside this medium, you must physically connect each new device to the network separately. Let's take a look at these two mobile computing technologies and see how they compare. The primary distinctions between Fixed & Wireless Networks in mobile technology technologies are listed in the table below: Table 10.1 Wireless vs Fixed Networks Wireless Networks Fixed Networks In a wireless network, there is no need A physical configuration is necessary in Fixed for any physical configuration. Networks in all circumstances. Wireless networks have a high data loss Because a flawless link is established between rate. both the devices in Fixed Networks, data loss is very low. Wireless Networks have a lower data Fixed Networks have a high data transmission transmission rate than wired networks, rate, resulting in high speed. hence they give less speed. Wireless networks have a lot of latency, In Fixed Networks, latency is not a concern which leads to even more delay. because a perfect connection is created between the devices, resulting in minimal delay. Wireless Networks can be hacked, which Connections to fixed networks are extremely is why security in this form of network is secure. always minimal. 10.5 2G In 1991, Finland debuted the second role of cellular telecommunications. It was based on the GSM protocol. It allows for data transmission such as text messaging (SMS - Short Message Service), photo or picture transfer (MMS - Multimedia Messaging Service), but not video transmission. Later versions of this generation, known as 2.5G (General Packet Radio Service) and 2.75G (Enhanced Data Rates for GSM Evolution), used GPRS (General Packet Radio Service) and EDGE (Enhanced Data Rates of GSM Evolution) networks. It has a higher capacity and quality. 188 CU IDOL SELF LEARNING MATERIAL (SLM)

Fig 10.6 2G Wireless systems Disadvantages • Incapable of dealing with complicated data, such as video • Strong digital signals are required. 10.6 3G Fig 10.7 3G Wireless system • The third generation, or 3G, was first introduced in the early 2000s. • The data transfer rate has been doubled to 2Mbits/s, allowing you to send and receive huge email messages. 189 CU IDOL SELF LEARNING MATERIAL (SLM)

• Its use of packet switching instead of circuit switching for transferring data is the fundamental distinction between 3G and 2G. • Communication that is more rapid • Is it better to have a faster internet connection or to have more security? • Conferencing via video • Gaming in three dimensions • 3G functions include TV streaming, mobile TV, and phone calls, among others. Disadvantages • Costly • High bandwidth is required. • 3G phones aren't cheap. • Cell phones were colossal in size. 10.7 4G Fig 10.8 4G Wireless system • 4G is indeed the fourth-generation mobile telecommunications, first introduced in 2010. • The LTE (Long Term Evolution) and LTE advanced protocols were used. • Provide video calling, real-time language translation, and video voice mail, among other communication services. • It was capable of speeds ranging from 100 Mbps to 1 Gigabit per second. 190 CU IDOL SELF LEARNING MATERIAL (SLM)

• High security and QoS (Quality of Service). • The term MAGIC is then used to describe 4G technology. When and where: • M is an abbreviation for mobile multimedia. • A - At any moment and at any location • Support for global mobility (G). • C - Customized personal service I - Integrated wireless solution Disadvantages • It consumes more battery. • Implementation is difficult. • There is a need for expensive equipment. 10.8WIRELESS LAN: AN OVERVIEW The term \"wireless LAN\" refers to a network that is not connected to the internet. LAWN is another name for it (Local Area Wireless Network). WLAN refers to a wireless connection that allows a mobile device to interact to a Local Area Network (LAN). Wireless LAN technologies are defined by the IEEE 802.11 group of standards. The Ethernet protocol and CSMA/CA are used in the 802.11 standard for path sharing (carrier sense multiple access with collision avoidance). It also employs a cryptographic mechanism known as the wired equivalent privacy algorithm. Wireless LANs provide high-speed data connectivity in small spaces, such as an office or a building. WLANs allow users to walk around while keeping connected to the network in a confined space. In certain circumstances, wireless LAN technology is utilised to save money by avoiding the installation of cable, while in others, it is the only way to provide public access to high-speed internet. Wireless solutions are springing up everywhere for whatever reason. WLANs such as NCR's wave LAN and Motorola's ALTAIR are currently available. Advantages of WLAN Flexibility: Nodes can communicate without restriction within radio coverage. Senders and receivers can be put anywhere, and radio waves can penetrate walls (also non-visible, e.g., within devices, in walls etc.). Wireless ad-hoc networks are the only networks that allow communication without prior preparation; any wired network requires wiring designs. 191 CU IDOL SELF LEARNING MATERIAL (SLM)

Design: Wireless networks enable the creation of self-contained, compact devices that can be slipped into a pocket, for example. Cables limit not just consumers but also manufacturers of small notepads, PDAs, and other devices. Robustness: Wireless networks can withstand calamities such as earthquakes, floods, and other natural disasters, whereas wired networks will typically fail totally in disasters. Installing and maintaining a wireless LAN is less expensive on average than installing and maintaining a standard wired LAN for two reasons. First, adding more users to a network after providing wireless access to the network via an access point for the very first user does not increase the cost. Second, wireless LAN reduces the upfront costs of cable as well as the labour required to build and maintain it. Ease of Use: Wireless LAN is simple to use, and consumers only require a small amount of new information to benefit from WLANs. WLANs have a number of drawbacks. Wireless LAN services are often of poorer quality than conventional networks. The main reasons for this are limited bandwidth due to radio transmission limits, higher error rates due to interference, and increased delay/delay fluctuation due to extensive error correction & detection methods. Proprietary Solutions: Because to the slowness of standardisation procedures, several businesses have developed proprietary solutions that include standardisation functions as well as a slew of additional capabilities. The IEEE 802.11a or 802.11b basic standards are used by most components nowadays. Restrictions: Several government and non-government organisations throughout the world control the operation and set frequency limits to reduce interference. Because wireless LAN products are offered in every country, domestic and international frequency rules must be taken into account. Low Power: Wireless LAN devices, as well as wireless devices that run on battery power, consume a lot of power. The LAN design, on the other hand, should take this into consideration and include specialized power saving modes & power management functions. Operating without a licence: LAN operators do not wish to apply for a particular licence in order to utilise the product. The device must operate in a band that does not require a licence, such as the 2.4 GHz ISM band. Wireless LANs that use radio transmission are susceptible to interference from a variety of other electrical equipment (such as vacuum cleaner, train engines, hair dryers, etc.). In a typical office or production environment, wireless LAN transceivers could be tuned for optimal transmission. 192 CU IDOL SELF LEARNING MATERIAL (SLM)

10.9WI-FI WIFI Wi-Fi (sometimes spelled Wi-Fi) is a wireless local area network technology. It allows an electrical device to use ISM radio bands to transport data or connect to the internet. It is a wireless local area network's core technology (WLAN). Computer systems can communicate more than a wireless network using Wi-Fi. Wi-Fi network components were based on one of the IEEE's 802.11 standards, which the Wi- Fi Alliance has embraced. It offers a common method of connecting to a wireless network. The Wi-Fi alliance's trademark Wi-Fi is used as a brand name for products that adhere to the IEEE 802.11 specifications. Personal computers, video game consoles, smart phones, digital cameras, tablet computers, and other devices can all connect to Wi-Fi. Within a 20-meter range, Wi-Fi can be used to create a hotspot (66 feet). Because an attacker does not need a physical connection to utilise Wi-Fi, it is less secure than a cable connection. Technical Information IEEE 802.11 specifications underpin Wi-Fi. This is a chronological listing of Wi-Fi standards. 802.11a 802.11b 802.11g 802.11n 802.11ac A wireless access point (802.11b or 802.11g) enables internet connectivity to desktops, laptops, smart phones, and other devices across a range of 120 feet indoors and 300 feet outdoors. 10.10WI-MAX WiMAX is one of today's most popular broadband wireless technologies. WiMAX systems are projected to provide cost-effective broadband access to both household and business consumers. WiMAX is a standardised wireless version of Ethernet designed to give broadband connectivity to client premises as an alternative to cable technologies (including Cable Modems, DSL, and T1/E1 lines). WiMAX is a trade association founded by leading communications, component, and equipment companies to promote & certify compatibility and interoperability for broadband 193 CU IDOL SELF LEARNING MATERIAL (SLM)

wireless access equipment that complies with the IEEE 802.16 and ETSI HIPERMAN specifications. WiMAX would work similarly to Wi-Fi, but at higher speeds and for a larger number of users over longer distances. WiMAX has the capacity to deliver service even in locations where wired infrastructure is difficult to reach, as well as the ability to bypass traditional wired infrastructure's physical limits. WiMAX was founded in April 2001, in preparation of the release of the initial IEEE 802.16 specifications for the 10-66 GHz band. WiMAX corresponds to 802.16 in the same way that the Wi-Fi Alliance corresponds to 802.11. Worldwide Interoperability for Microwave Access (WiMAX) is an acronym for Microwave Access. Wireless MAN technology is used. A wireless technology that is optimised for delivering IP-centric services over a large geographic region. A wireless platform that may be scaled to build alternative or complementary broadband networks. An interoperability certification for equipment built to an IEEE 802.16 or comparable standard. The IEEE 802.16 Working Group creates standards for two distinct usage models. A model of fixed usage (IEEE 802.16-2004). A model for use on the go (IEEE 802.16e). What exactly is 802.16a? WiMAX is such a simple phrase that many people confuse it with the 802.16 standards and technology, even though it only applies to systems that meet the WiMAX Forum's specified compliance criteria. The 802.16a specification for 2-11 GHz is indeed a wireless metropolitan area network (MAN) technology which will enable fixed, portable, and nomadic devices with broadband wireless access. It can link 802.11 hotspots to the Internet, enable campus connectivity, and serve as a wireless alternative for cable and DSL for last-mile broadband access. WiMAX Range and Speed Depending on the technical configuration chosen, WiMAX is estimated to initially offer up to around 40 Mbps per wireless channel for both fixed and portable applications, enough to serve hundreds of companies with T-1 speed connectivity and thousands more residences with DSL speed connectivity. WiMAX can transmit speech and video as well as data via the Internet. 194 CU IDOL SELF LEARNING MATERIAL (SLM)

WiMAX was created to give wireless broadband connectivity to buildings, either in competition with existing wired networks or as a stand-alone service in underserved rural and sparsely populated areas. WLAN hotspots can also be connected to the Internet with this device. WiMAX is also designed to give mobile devices with high-speed Internet access. Although it would not be as fast as in these stationary applications, a 15 Mbps capacity in a 3 km cell coverage area is expected. Users would be able to break away behind today's Internet access arrangements and go online at broadband speeds practically anywhere within a Metro Zone with WiMAX. WiMAX might be used in a number of spectrum bands, including 2.3GHz, 2.5GHz, 3.5GHz, and 5.8GHz. What is the benefit of WiMAX? WiMAX can meet a wide range of access requirements. Broadband capabilities could be extended to bring them closer to subscribers, filling gaps in cable, DSL, and T1 services, Wi- Fi, and cellular backhaul, providing last-100-meter access from fibre to the curb, and giving service providers a further cost-effective option for supporting broadband services, among other things. Where large spectrum deployments (i.e.,>10 MHz) are requested, WiMAX can enable very high bandwidth solutions using existing infrastructure, lowering costs while delivering the bandwidth required to serve a full variety of high-value multimedia applications. Because of its ability to effortlessly interoperate across many network types, WiMAX can assist service providers in meeting many of the issues they face as a result of rising client expectations without requiring them to abandon their existing infrastructure investments. For applications ranging between real-time delay-sensitive voice-over-IP (VoIP) to real-time live streaming and non-real-time downloads, WiMAX could provide wide area coverage with quality-of-service capabilities, ensuring that users get the performance they expect for all sorts of communications. WiMAX is an IP-based wireless broadband technology that can be incorporated through both wide-area third-generation (3G) mobile & wireless networks, as well as landline networks, to create a seamless anytime, everywhere broadband solution. WiMAX is expected to be the next phase in the evolution of 3G mobile phones, with a different pair of WiMAX and CDMA standards known as 4G. WiMAX Objectives A standard isn't enough to ensure widespread adoption. WiMAX has stepped forward to assist in the removal of adoption constraints including such interoperability and deployment costs. By defining and conducting compatibility testing and designating vendor solutions with 195 CU IDOL SELF LEARNING MATERIAL (SLM)

a \"WiMAX CertifiedTM\" mark once testing is done satisfactorily, WiMAX will help spark the wireless MAN industry. 10.11 SUMMARY • Wireless communications are indeed a type of data transmission that takes place over the air. This is a wide phrase that encompasses all procedures and methods for communication between two or more devices via wireless communication between devices employing a wireless signal. • Electromagnetic signals are emitted by an enabled device inside the air, physical environment, or atmosphere to enable wireless communication. A sender or an intermediate device to spread wireless signals can be used as the sending device. • When the destination and receiving intermediate device receives these signals, a wireless transmission bridge between both the sender and receiver device is created. Wireless communication comes in a variety of shapes, sizes, and technologies, as well as delivery techniques, such as: Communication by satellite, Communication on the go, Communication over a wireless network, Communication using infrared, Communication using Bluetooth • Despite the fact that the fundamental architecture of these communication technologies differs, they all lack a physical or connected connection between their respective devices to initiate and execute communication. • The N-tier architecture allows you to manage all of an application's components (business layer, presentation layer, and database layer) from a single location. • N-tier architecture is useful for applications with a small number of users on a local area network. This type of architectural design ensures that an application can be efficiently maintained, scaled up, and deployed on the Internet. 10.12KEYWORDS • 2G – Delivers digital signal and offers up to 250Kbps speed. Supports voice, text and data services. • 3G – At least 200Kbps up to 3Mbps speed. • 4G – 4G delivers up to 100Mbps for mobile access, and up to 1Gbps for wireless access 10.13 LEARNING ACTIVITY 1. Identify the three-tier architecture from your institution with respect to application layer, business layer and database layer. 196 CU IDOL SELF LEARNING MATERIAL (SLM)

___________________________________________________________________________ ___________________________________________________________________________ 2. Analyse the wire line telecom network and its evolving structure. ___________________________________________________________________________ ___________________________________________________________________________ 10.14 UNITEND QUESTIONS A. Descriptive Questions Short Questions 1. Define Wireless networks. 2. List the limitations of wireless network. 3. Define Radio Frequency. 4. What is wave propagation? 5. Write the benefits of 2G. Long Questions 1. Explain the advantages and disadvantages of 3G. 2. Explain the working of Wi-fi. 3. Compare common wireless system. 4. Describe the advantages of WLAN flexibility. 5. What are the drawbacks of WLAN’s? B. Multiple Choice Questions 1. Most wireless devices must adhere to the ____ standard a. IEEJ b. IEE c. IEEE d. IJEE 2. ________interference can occur when a large number of network devices communicate at the same time a. Radio frequency 197 CU IDOL SELF LEARNING MATERIAL (SLM)

b. transmitter c. receiver d. signal 3. The number of cycles per second is known as_____. a. electric signals b. transmitter c. waves d. frequency 4. 3Gs was introduced in ____. a. 1990’s b. 1980’s c. 2000’s d. 1950’s 5. MAGIC is used to describe ____ a. 2G b. 3G c. 4G d. 5G Answers 1-c, 2- a, 3- d, 4- c, 5-c 10.15 REFERENCES Reference books • Behrouz A Forouzan, “Data Communications and Networking”, McGraw Hill. • Andrew S. Tanenbaum, “Computer Networks”, Pearson Education. • Subir Kumar Sarkar, T.G. Basavaraju, C. Puttaamadappa, “AdHoc Mobile Wireless Network: Principles, Protocols, and Applications, CRC Press. 198 CU IDOL SELF LEARNING MATERIAL (SLM)

Textbook references • James F. Kurose, Keith W. Ross, “Computer Networking”, Pearson Education. • Michael A. Gallo, William M. Hancock, “Computer Communications and NetworkingTechnologies”, CENGAGE Learning Websites: • https://www.techopedia.com/definition/10062/wireless-communications • https://www.computernetworkingnotes.com/ • https://www.guru99.com 199 CU IDOL SELF LEARNING MATERIAL (SLM)

UNIT 11-INTRODUCTION TO WIRELESS COMMUNICATION SYSTEM 2 STRUCTURE 11.0 Learning Objectives 11.1 Introduction to Wireless Communication System 11.2 Mobile Adhoc Network (MANET) or Wireless Adhoc Network 11.3 Wireless network security concerns 11.4 Wireless security threats: 5 solutions 11.5 Threats and issues with wireless networks 11.6 Reduce the dangers 11.7 Summary 11.8 Keywords 11.9 Learning activity 11.10 Unit End Questions 11.11 References 11.0 LEARNING OBJECTIVES After studying this unit, you will be able to: • Learn the concepts of wireless communication systems • Explain the working principle of MANET • List the security threats of wireless communication • Explain the challenges of communication systems 11.1 INTRODUCTION TO WIRELESS COMMUNICATION SYSTEM Wireless communication refers to the transfer of data over a long distance without the need of wires, cables, or other electrical conductors. Wireless communication is a wide term that encompasses all procedures and ways of connecting and communicating among two or more devices via wireless communication between devices employing a wireless signal. Wireless Communication Characteristics 200 CU IDOL SELF LEARNING MATERIAL (SLM)