Mobile Computing Lecture 1.pdf

Lecture 1 Introduction to Wireless Networks By: Dr. Hajar Esmaeil As-Suhbani 1 IT, 4th Level  Outline  Introduction  Brief history of wireless networks  Elements of a wir...

Lecture 1 Introduction to Wireless Networks By: Dr. Hajar Esmaeil As-Suhbani 1 IT, 4th Level  Outline  Introduction  Brief history of wireless networks  Elements of a wireless network  Classification of wireless networks:  WPAN  WLAN  WMAN  WWAN  Wireless network architectures:  Logical architecture  Physical architecture  End-user applications  Wireless Voice and Data Networks 2  Introduction  Wireless networks are networks that use radio waves to connect devices, without the using of cables.  Wireless networks work similar to wired networks, however, wireless networks must convert information signals into a form suitable for transmission through the air medium.  Wireless networks use radio waves or infrared light for communication.  Wireless networks serve many purposes:  In some cases they are used as cable replacements, while in other cases they are used to provide access to corporate data from remote locations.  Wireless infrastructure can be built for very little cost compared to traditional wired alternatives.  Mobile communication is needed.  Devices commonly used for wireless networking include portable computers, desktop computers and cellular phones, etc. 3  Problems with Wireless Networks  There are some issues related to the legal regulation of the electromagnetic spectrum.  Electromagnetic waves are transmitted through many devices, but are prone to interference, signal loss and noise.  In addition, electromagnetic waves are not easily confined to a restricted geographic area, so is more susceptible to eavesdropping.  For this reason, a hacker can easily listen to a network if the data transmitted are not encoded.  Therefore, all necessary steps should be taken to ensure the privacy of data transmitted over wireless networks.  Generally, wireless facilities have lower data rates than guided facilities.  Frequencies can be more easily reused with guided media than with wireless media. 4  Brief history of wireless networks  Guglielmo Marconi invented the wireless telegraph in 1896.  Communication by encoding alphanumeric characters in analog signal  Sent telegraphic signals across the Atlantic Ocean.  Communications satellites launched in 1960s.  IG of wireless telephone technology, mobile telecommunications, which was launched in Japan by NTT in 1979.  2G of mobile telecommunication was launched in Finland in 1991.  June 1997 802.11 "WiFi" protocol first release.  3G was introduced in early 2000s.  4G was appeared in 2010.  The big three Chinese operators launched 5G services on October 31, 2019, instantly becoming global 5G leaders with nearly 10 million advance orders.  6G specification development and standardization is slated for 2025-2029. 5  Elements of a Wireless Network network infrastructure 6  Wireless Hosts  Laptop, smartphone  Run applications  May be stationary (non- mobile) or mobile network  Wireless does not always infrastructure mean mobility 7  Base Station  Typically connected to wired network  Relay - responsible for sending packets between wired network and network wireless host(s) in its infrastructure “area”  E.g., Cell towers, 802.11 access points 8  Wireless Link  Typically used to connect mobile(s) to base station  Also used as backbone link network  Multiple access protocol infrastructure coordinates link access  Various data rates, transmission distance 9  Classification of wireless networks  Wireless networks can be classified into four specific groups according to the area of application and the signal range: 1. Wireless Personal-Area Networks (WPAN) 2. Wireless Local-Area Networks (WLANs) 3. Wireless Metropolitan-Area Networks (WMAN) 4. Wireless Wide-Area Networks (WWAN) 10  …Classification of wireless networks  In addition, wireless networks can be also divided into two broad segments:  Short- range  Long-range 11  Short-range wireless networks  Short-range wireless is related to networks that are confined to a limited area, which applies to local area networks (LANs), such as corporate buildings, school campuses, manufacturing plants or homes, as well as to personal area networks (PANs) where portable computers within close proximity to one another need to communicate.  These networks typically operate over unlicensed spectrum reserved for industrial, scientific and medical (ISM) usage.  The available frequencies differ from country to country.  The most common frequency bands are at 2.4 GHz and at 5 GHz.  The availability of these frequencies allows users to operate wireless networks without obtaining a license, and without charge.  As a license is not required for use, this has facilitated the expansion of such networks. 12  Long-range wireless networks  In long-range networks, connectivity is typically provided by companies that sell the wireless connectivity as a service.  These networks span large areas such as a metropolitan area (WMAN), a state or province, or an entire country.  The goal of long-range networks is to provide wireless coverage globally.  The most common long-range network is wireless wide area network (WWAN).  When true global coverage is required, satellite networks are also available. 13  Wireless Personal-Area Networks (WPAN)  Wireless Personal Area Networks are based on the IEEE 802.15 standard.  They permit communication in a very short range, of about 10 meters.  Unlike other wireless networks, a connection made through a WPAN involves no infrastructure.  This allows small, power efficient, inexpensive solutions to be implemented for a wide range of devices such as a smartphone and a PDA.  These networks are characterized by low power demands and a low bit rate.  Such kind of networks relay on technologies such as Bluetooth, IrDA, ZigBee.  It is free from radio frequency interference.  The line-of-sight requirement between computer devices limits the placement of wireless components. 14  Wireless Personal-Area Networks (WPAN): Bluetooth  Most wireless PANs use radio waves for carrying information through air, for example, the Bluetooth.  Bluetooth corresponds to the IEEE 802.15.1 standard.  Originally Bluetooth was designed for low power consumption, short range and omni-directional (point to multipoint) communications, and cheap devices, to be used as a cable replacement, linking devices through an ad- hoc connection of radio waves.  Bluetooth technology uses the 2.4 GHz ISM spectrum band (2400 to 2483.5 MHz).  In addition, the 2.4 GHz band is available worldwide, making it a true standard for low-power wireless connectivity.  From an application point of view, Bluetooth is intended for a cordless mouse, keyboard, and hands-free headset. 15 Wireless Personal-Area Networks (WPAN): IrDA  Some wireless PANs employ infrared light to carry information from one point to another.  As infrared data communications, based on standards from the Infrared Data Association (IrDA), become widely available on personal computers and peripherals, a timely opportunity exists for effective and inexpensive short range wireless  IrDA is a low-power, low-cost, unidirectional (point to point), narrow angle (< 30º) cone, ad hoc data transmission standard designed to operate over a distance of up to 1 meter and at speeds of 9600 bps to 4 Mbps (currently), 16 Mbps (under development).  Some of the devices that use IrDA are notebooks, PDAs, printers and cameras. 16  Wireless Personal-Area Networks (WPAN): ZigBee  ZigBee is designed for reliable wirelessly networked monitoring and control networks.  ZigBee is based on the IEEE 802.15.4 standard and was developed as an open global standard to address the unique needs of easy implementation, high reliability, low-cost, low-power and low-data rate wireless device networks.  ZigBee operates the unlicensed bands including 2.4 GHz, 900 MHz and 868 MHz at a maximum transfer rate of 250 Kbps, enough to satisfy sensor and automation needs using wireless.  ZigBee also serves for creating larger wireless networks not demanding high data throughput.  Indoors, ZigBee typically manages multiple devices within a range of 10 to 100 meters.  While outdoors, Zigbee range extend their reach to about 300 meters. 17 …Wireless Personal-Area Networks (WPAN): ZigBee  With ZigBee, you can connect smart devices like lights, outlets, locks, and switches within your smart home network. 18  Wireless Local-Area Network (WLAN)  Wireless Local Area Networks (WLANs) are designed to provide wireless access in areas with a typical range up to 100 meters and, are used mostly in home, school, computer laboratory, or office environments.  This gives users the ability to move around within a local coverage area and still be connected to the network.  WLANs are based on IEEE 802.11standards, marketed under the Wi-Fi brand name.  The IEEE 802.11 is a family of different standards for wireless local area networks. 19  …Wireless Local-Area Network (WLAN) 20  Wireless Metropolitan-Area Network (WMAN)  WMANs are based on IEEE 802.16 standard which is often called WiMAX (Worldwide Interoperability for Microwave Access).  WiMAX is similar to Wi-Fi, but provides coverage over greater distances.  WiMAX is a communications technology that supports point to multipoint architecture aimed at providing high-speed wireless data over metropolitan area networks.  This enables smaller wireless LANs to be interconnected by WiMAX creating a large WMAN.  Thus, networking between cities can be achieved without the need for expensive cabling.  WiMAX operates on two frequency bands, a mixture of licensed and unlicensed band, from 2 GHz to 11 GHz and from 10 GHz to 66 GHz, and can transfer around 70 Mbps over a distance of 50 km to thousands of users from a single base station. 21  …Wireless Metropolitan-Area Network (WMAN) 22  Wireless Wide-Area Network (WWAN)  Wireless Wide Area Networks extend beyond 50 kilometres and typically use licensed frequencies.  A Wireless WAN is Capable of Supporting Mobile Applications over a Wide Area.  These types of networks can be maintained over large areas, such as cities or countries, via multiple satellite systems or antenna sites looked after by an internet services provider (ISP).  There are mainly two available technologies: 1. Digital cellular telephony 2. Satellites 23  Comparison of wireless networks types 24  Wireless Network Architectures: Logical architecture  The logical architecture of a network refers to the structure of standards and protocols that enable connections to be established between physical devices, or nodes, and which control the routing and flow of data between these nodes.  The logical architecture of wireless networks is described with reference to the OSI model. 25  Wireless Network Architectures: Physical Architecture  In wireless networks there are two modes for configuring a wireless architecture, ad hoc and infrastructure. 26  Infrastructure Mode  Base station connects mobiles into wired network  Handoff: mobile changes base station providing network connection into wired infrastructure network 27  Ad hoc Mode  No base stations  Nodes can only transmit to other nodes within link coverage  Nodes organize themselves into a network: route among themselves 28  Wireless Network Taxonomy Single Hop Multiple Hops Infrastructure Host connects to base station Host may have to relay (e.g., Aps) (WiFi, WiMAX, cellular) which through several wireless connects to larger Internet nodes to connect to larger Internet: mesh net No No base station, no No base station, no infrastructure connection to larger Internet connection to larger (Bluetooth, ad hoc nets) Internet. May have to relay to reach other a given wireless node MANET, VANET 29  Wireless Networks End-user Applications  Vehicles: Transmission of music, news, road conditions, weather reports, and other broadcast information are received via digital audio broadcasting (DAB) with 1.5Mbit/s.  Business: Wireless technology saves businesses or companies a considerable amount of money on installations costs.  Transportation Industries: In transportation industries, GPS technology is used to find efficient routes and tracking vehicles.  Entertainment and Education: Wireless networks can provide information at any appropriate location by outdoor internet access. 30  Wireless Voice and Data Networks  Wireless voice and data networks refer to communication systems that transmit voice calls, internet data, and other information wirelessly, without the need for physical connections like cables.  Voice Communication:  Traditionally handled by cellular networks using technologies like 2G, 3G, and now predominantly 4G and 5G for higher-quality voice calls.  Voice over Internet Protocol (VoIP) is increasingly popular, utilizing internet connections (including wireless ones) to make voice calls.  Data Communication:  Mobile Data: Enables internet access over cellular networks, allowing users to browse the web, send emails, and use various applications.  Wi-Fi: Provides high-speed internet access to devices within its coverage area, commonly used in homes, businesses, and public spaces. 31 THANK YOU!