**3. Different kinds of wireless network**

Network means a group of devices interconnected to perform specified task. To achieve that purpose we have two distinct technologies namely 'wired network' and 'wireless network'. Between these two, 'wireless network technology' is often preferred in terms of flexibility, user mobility, network access and so on. In 'wireless sensor network' data is transferred through radio frequency unlike a wired network where data transmission takes place through Physical cables. There are different types of wireless network system in vogue depending on the data rate or coverage area (**Figure 3**).

W-WAN (Wireless Wide Area Network):-

As the name suggests, this is a network system that can provide long distance transmission of data, voice, image and video information over a large geographical area. The range of W-WAN is beyond 100 km. This kind of network is used in GSM, telephonic calls, surfing web pages etc.

Technologies used in W-WAN:

1.ISDN (Integrated Service Digital Network) – It is one of the technologies that is used to transmit data, voice and signaling and it is a circuit-switched telephone network system. It is well known for providing better speed and quality than traditional connections.

**Figure 3.** *Different kinds of WSN.*


W-MAN (Wireless Metropolitan Area Network):

This is a wireless network system which has the capability to cover an area of approximately the size of a city and it sits somewhere between W-LAN and W-WAN. The connections can be point to point or point to multiple networks.

W-LAN (Wireless Local Area Network):

A wireless LAN is a wireless computer network two or more devices using wireless connection to form a local area network within a limited area such as home, school, computer laboratory, campus or office building.

W-PAN (Wireless Personal Area Network):

A personal area network is a computer network for interconnecting electronic devices within an individual person's workplace. A PAN provides data transmission among devices such as computers, smartphones, tablets [8] and personal digital assistants.
