+ Basic Service Set (BSS): uses only a single AP to create a WLAN * Infrastructure mode: Connect to a wired LAN, supports two modes (service sets): * Ad-hoc mode: In this mode devices send data directly to each other without an AP. Products certified as Wi-Fi compliant are interoperable with each other even if they are made by different manufacturers.Īccess points can support several or all of the three most popular IEEE WLAN standards including 802.11a, 802.11b and 802.11g. The term Wi-Fi was created by the Wireless Ethernet Compatibility Alliance (WECA). Wi-Fi: stands for Wireless Fidelity and is used to define any of the IEEE 802.11 wireless standards. To accommodate wireless LAN’s, the FCC has set aside bandwidth for unlicensed use including the 2.4Ghz spectrum where many WLAN products operate. ISM Band: The ISM (Industrial, Scientific and Medical) band, which is controlled by the FCC in the US, generally requires licensing for various spectrum use. Maximum transmission speed is 54Mbps and approximate wireless range is 100-200 feet indoors. * 802/11g: operates in the 2.4 GHz ISM band. Maximum transmission speed is 11Mbps and approximate wireless range is 100-200 feet indoors. * 802.11b: operates in the 2.4 GHz ISM band. Maximum transmission speed is 54Mbps and approximate wireless range is 25-75 feet indoors. * 802.11a: operates in the 5.7 GHz ISM band. + Wi-Fi Alliance: improves the interoperability of wireless products among vendorsīut the most popular type of wireless LAN today is based on the IEEE 802.11 standard, which is known informally as Wi-Fi. + IEEE: specifies how RF is modulated to transfer data + ITU-R: is responsible for allocation of the RF bands Nowadays there are three organizations influencing WLAN standards. + If no acknowledgment is received, resend the data + Wait for an acknowledgment that data has been sent successfully + When the random time has passed, listen again. If it is free, set a random time before sending data WLAN can’t use CSMA/CD as a sending device can’t transmit and receive data at the same time. The major difference between wired LAN and WLAN is WLAN transmits data by radiating energy waves, called radio waves, instead of transmitting electrical signals over a cable.Īlso, WLAN uses CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) instead of CSMA/CD for media access. Unlike a wired network which operates at full-duplex (send and receive at the same time), a wireless network operates at half-duplex so sometimes an AP is referred as a Wireless Hub. Below is an example of a simple WLAN:Įach WLAN network needs a wireless Access Point (AP) to transmit and receive data from users. Wireless LANs enable users to communicate without the need of cable. Maybe you have ever used some wireless applications on your laptop or cellphone. Wireless LAN (WLAN) is very popular nowadays. Alfred Glkossbrenner-Internet 101 Computing MGH, 2013īelow is the link to download Internet Fundamentals notes.In this article we will discuss about Wireless technologies mentioned in CCNA.Networking Essentials – Firewall Latest-2015.Network firewalls, Kironjeet syan -New Rider 2014.Complete idiots guide to javascript, Aron Weiss, QUE, 2013.Fundamentals of the Internet and the World Wide Web, Raymond Greenlaw and Ellen Hepp, TMH- 2012.Internet & World Wide Programming, Deitel, Deitel & Nieto, 2012, Pearson Education.Privacy and security topics: Introduction, Software Complexity, Attacks, security and privacy levels, security policy, accessibility and risk analysis, Encryption schemes, Secure Web document, Digital Signatures, Firewalls, Intrusion detection systems Introduction to Web Servers: PWS, IIS, Apache Microsoft Personal Web Server. Languages: Basic and advanced HTML, Basics of scripting languages – XML, DHTML, JavaScript. Introduction, advantages and disadvantages, User Ids, Passwords, e-mail addresses, message components, message composition, mailer features, E-mail inner workings, E-mail management, MIME types, Newsgroups, mailing lists, chat rooms, secure-mails, SMTP, PICO, Pine, Library cards catalog, online ref. Introduction, Miscellaneous Web Browser details, searching the FrontPage Express, Plug-ins. Modes of Connecting to Internet, Internet Service Providers(ISPs), Internet address, standard address, domain name, DNS, IP.v6.Modems, Speed and time continuum, communications software internet tools. Introduction to networks and internet, history, Internet, Intranet & Extranet, Working of Internet, Internet Congestion, internet culture, business culture on the internet. Internet Fundamentals is a subject that deals with the internet and transmission of data packets over the internet, various protocols, and rules.īelow is the syllabus for Internet Fundamentals:.
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