The Latest Development In Networks And Communications

The Latest Development in Networks and Communications 1.0 Introduction A computer network is a system of interconnected computers and peripheral devices. For example, it may connect computers, printers, scanners and cameras. Communications is about the transfer of information from a sender, across a distance, to a receiver whilst Computers communicate with digital signals. The older forms of communications technology, such as telephones and radios, use analog signals. 2.0 Mobile Computing 2.1 definition Mobile computing is a generic term describing one's ability to use technology while moving, as opposed to portable computers, which are only practical for use while deployed in a stationary configuration. Many types of mobile computers have been introduced since the 1990s, including the: •

Wearable computer

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Personal digital assistant/Enterprise digital assistant

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Smartphone

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Carputer

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Ultra-Mobile PC

2.2 Specification, services, and frequencies of Mobile Computing Personal digital assistants (usually abbreviated to PDAs) are handheld devices that were originally designed as personal organizers, but became much more versatile over the years. The many uses and tasks of a basic PDA include many features: calculating, use as a clock and calendar, playing computer games, accessing the Internet, sending and receiving E-mails, use as a radio or stereo, video recording, recording notes, use as an address book, and use as a spreadsheet. Newer PDAs also have both color screens and audio capabilities, enabling them to be used as mobile phones (PDA Phone), web browsers or media players. Many PDAs can

access the Internet, intranets or extranets via Wi-Fi, or Wireless Wide-Area Networks (WWANs). 3.0 Internet technology and services 3.1 VoIP Voice over Internet Protocol (VoIP) is a general term for a family of transmission technologies for delivery of voice communications over IP networks such as the Internet or other packet-switched networks. Other terms frequently encountered and synonymous with VoIP are IP telephony, Internet telephony, voice over broadband (VoBB), broadband telephony, and broadband phone. Internet telephony refers to communications services-voice, facsimile, and voice-messaging applications-that are transported via the Internet, rather than the public switched telephone network (PSTN). The basic steps involved in originating an Internet telephone call are conversion of the analog voice signal to digital format and compression/translation of the signal into Internet protocol (IP) packets for transmission over the Internet; the process is reversed at the receiving end. VoIP systems employ session control protocols to control the set-up and tear-down of calls as well as audio codes which encode speech allowing transmission over an IP network as digital audio via an audio stream. Codec use is varied between different implementations of VoIP (and often a range of codes are used); some implementations rely on narrowband and compressed speech, while others support high fidelity stereo codes. 3.2 BLOG A blog is a type of website, usually maintained by an individual with regular entries of commentary, descriptions of events, or other material such as graphics or video. Entries are commonly displayed in reverse-chronological order. Many blogs provide commentary or news on a particular subject; others function as more personal online diaries. A typical blog combines text, images, and links to other blogs, Web pages, and other media related to its topic. The ability for readers to leave comments in an interactive format is an important part of many blogs. Most blogs are primarily textual,

although some focus on art (artlog), photographs (photoblog), sketches (sketchblog), videos (vlog), music (MP3 blog), and audio (podcasting). Micro-blogging is another type of blogging, featuring very short posts. 4.0 Types of network 4.1 PAN A personal area network (PAN) is a computer network used for communication among computer devices close to one person. Some examples of devices that are used in a PAN are personal computers, printers, fax machines, telephones, PDAs, scanners, and even video game consoles. Such a PAN may include wired and wireless connections between devices. The reach of a PAN is typically at least about 20-30 feet (approximately 6-9 meters), but this is expected to increase with technology improvements. 4.2 VPN A virtual private network (VPN) is a computer network in which some of the links between nodes are carried by open connections or virtual circuits in some larger network (e.g., the Internet) instead of by physical wires. The data link layer protocols of the virtual network are said to be tunneled through the larger network when this is the case. One common application is secure communications through the public Internet, but a VPN need not have explicit security features, such as authentication or content encryption. VPNs, for example, can be used to separate the traffic of different user communities over an underlying network with strong security features. A VPN may have best-effort performance, or may have a defined service level agreement (SLA) between the VPN customer and the VPN service provider. Generally, a VPN has a topology more complex than point-to-point. A VPN allows computer users to appear to be editing from an IP address location other than the one which connects the actual computer to the Internet. 4.3 WLAN WLANs provide wireless network communication over short distances using radio or infrared signals instead of traditional network cabling.

A WLAN typically extends an existing wired local area network. WLANs are built by attaching a device called the access point (AP) to the edge of the wired network. Clients communicate with the AP using a wireless network adapter similar in function to a traditional Ethernet adapter. Network security remains an important issue for WLANs. Random wireless clients must usually be prohibited from joining the WLAN. Technologies like WEP raise the level of security on wireless networks to rival that of traditional wired networks. 4.4 WIMAX WiMax is the industry term for a long-range wireless networking standard. WiMax technology has the potential to deliver high-speed Internet access to rural areas and other locations not serviced by cable or DSL technology. WiMax also offers an alternative to satellite Internet services. WiMax technology is based on the IEEE 802.16 WAN communications standard. WiMax signals can function over a distance of several miles / kilometers. Data rates for WiMax can reach up to 75 megabits per second (Mb/s). A number of wireless signaling options exist ranging anywhere from the 2 GHz range up to 66 GHz. 5.0 Conclusion Network communication is an ever-growing industry with new technologies and standards emerging every day. To use a communication network effectively you need to know the advantages and disadvantages, as well as the various types of networks possible. References http://www.wikipedia.com http:// compnetworking.com