A data network is an electronic communications process that allows for the orderly transmission and receptive of data, such as letters, spreadsheets, and other types of documents. What sets the data network apart from other forms of communication, such as an audio network, is that the data network is configured to transmit data only. This is in contrast to the audio or voice network, which is often employed for both voice communications and the transmission of data such as a facsimile transmission.
There are two basic types of data networks in operation today. The private data network is essentially a local network that is designed to allow for the transmission of data between the various departments within a given entity, such as a company. All locations of the company may be included as nodes on the network, and be able to communicate through a common server that functions as the repository for any and all data files that are used throughout the business. There are also examples of a private data network that allows for data sharing between several companies that are part of the same profession or industry. Connections to this type of network can be achieved through the creation of a virtual private network, or VPN that resides on a master server, or by provisioning the connections through a communications carrier.
In contrast to the private data network, the public data network will be widely accessible to both residential and corporate clients of a given carrier network. The setup of a public network may involve the utilization of multiple servers and connection to the network through several different processes. Often, a public data network will require some type of subscription process, such as a monthly usage fee. Upon receipt of the fee, the service provider will allow the creation of access credentials that will allow the consumer to access authorized portions of the network and engage in several functions commonly involved with data. These include the ability to retrieve stores documents, create backups of important data files, and archiving data such as historical information or other data that is understood to be valuable for future applications.
A) Personal Area Network: A personal area network – PAN – is a computer network organized around an individual person. Personal area networks typically involve a mobile computer, a cell phone and/or a handheld computing device such as a PDA. It can be used to transfer files including email and calendar appointments, digital photos and music. A personal area network (PAN) is a computer network used for communication among computerized devices, including telephones and personal digital assistants. PANs can be used for communication among the personal devices themselves (intrapersonal communication), or for connecting to a higher level network and the Internet (an uplink).
Personal area networks can be constructed with cables or be wireless. USB and FireWire technologies often link together a wired PAN, while wireless PANs typically use Bluetooth or sometimes infrared connections. Bluetooth PANs are also sometimes called piconets.
B) Metropolitan Area Network: A metropolitan area network (MAN) is a computer network that usually spans a city or a large campus. A MAN usually interconnects a number of local area networks (LANs) using a high-capacity backbone technology, such as fiber-optical links, and provides up-link services to wide area networks (or WAN) and the Internet.
C) Local Area Network: A local area network (LAN) supplies networking capability to a group of computers in close proximity to each other such as in an office building, a school, or a home. A LAN is useful for sharing resources like files, printers, games or other applications. A local area network (LAN) is a group of computers and associated devices that share a common communications line or wireless link. Typically, connected devices share the resources of a single processor or server within a small geographic area (for example, within an office building). Usually, the server has applications and data storage that are shared in common by multiple computer users. LAN links computers, i.e ., software and hardware, in the same area for the purpose of sharing information. Usually LAN links computers within a limited geographical area because they must be connected by a cable, which is quite expensive.
People working in LAN get more capabilities in data processing, work processing and other information exchange compared to stand-alone computers. Because of this information exchange most of the business and government organisations are using LAN.
Major Characteristics of LAN
- Every computer has the potential to communicate with any other computers of the network.
- High degree of interconnection between computers.
- Easy physical connection of computers in a network.
- Inexpensive medium of data transmission.
- High data transmission rate.
Advantages of LAN
- The reliability of network is high because the failure of one computer in the network does not effect the functioning for other computers.
- Addition of new computer to network is easy.
- High rate of data transmission is possible.
- Peripheral devices like magnetic disk and printer can be shared by other computers.
Disadvantage of LAN
If the communication line fails, the entire network system breaks down.
Use of LAN
Followings are the major areas where LAN is normally used:
- File transfers and Access.
- Word and text processing.
- Electronic message handling.
- Remote database access.
- Personal computing.
- Digital voice transmission and storage.
D) Wide Area Network: A Wide Area Network (WAN) is a network that covers a broad area using private or public network transports. Business and government entities utilize WANs to relay data among employees, clients, buyers, and suppliers from various geographical locations. In essence, this mode of telecommunication allows a business to effectively carry out its daily function regardless of location. The Internet can be considered a WAN as well, and is used by businesses, governments, organizations, and individuals for almost any purpose imaginable.
Advantages of WAN
- Messages can be sent very quickly to anyone else on the network. These messages can have pictures, sounds, or data included with them (called attachments).
- Expensive things (such as printers or phone lines to the internet) can be shared by all the computers on the network without having to buy a different peripheral for each computer.
- Everyone on the network can use the same data. This avoids problems where some users may have older information than others.
- Share information/files over a larger area.
Disadvantages of WAN
- Setting up a network can be an expensive and complicated experience. The bigger the network the more expensive it is.
- Security is a real issue when many different people have the ability to use information from other computers. Protection against hackers and viruses adds more complexity and expense.
- Once set up, maintaining a network is a full-time job which requires network supervisors and technicians to be employed.
- Information may not meet local needs or interests.