Wireless-Fidelity (Wi-Fi)

Wireless-Fidelity (Wi-Fi) 

Wi-Fi (or Wi-fi, wifi, Wifi, wifi) is short for Wireless Fidelity, has a standard set of terms that is used for Wireless Local Networks (Wireless Local Area Networks - WLANs) based on IEEE 802.11 specification. Connecting function within a local area network wirelessly. Wi-Fi was originally used for the use of wireless devices and local area network (LAN), but now more widely used to access the Internet. This allows anyone with a computer with a wireless card (wireless card) or personal digital assistant (PDA) to connect to the internet using an access point (hotspot) nearby.

Wi –Fi Spesification

Wi-Fi is designed based on the IEEE 802.11 specification. Now there are four variations of this ie 802.11: 802.11a, 802.11b, 802.11g, and 802.11n.B Specification is the first Wi-Fi products. Here are details of each variation is 802.11:

In many parts of the world for the frequencies used by Wi-Fi, users are not required to obtain permission from local regulators. Varian 802.11a obtain higher frequency and therefore its scope is narrower power than the other three variants are relatively similar.

Operational Technically, Wi-Fi is one variant of information and communications technology that works on the network and device WLAN (Wireless Local Area Network). In other words, the Wi-Fi is a certification trademark given to manufacturers of telecommunications equipment (Internet) working in WLAN networks and they fulfill the required quality interoperasi capacity.

Access Method Wi-Fi Connection

There are two ways to connect a PC with the Wi-Fi, ad hoc and infrastructure. Both methods have their advantages and disadvantages of each according to the conditions encountered during the execution of the installation of a wireless network as needed. 

The system is an ad hoc system of peer to peer, in the sense of a single computer connected to a computer with SSID to know. When shown is perhaps easier to imagine a system with a direct connection from one computer to another computer using a twisted pair cable without hub unit.

There are two computers with Wi-Fi devices can be connected directly without a tool called the access point mode. The ad hoc system to no longer recognize the central system (which is usually enabled on your access point). Adhoc system requires only one computer on which the name or just the SSID network name on a card / computer.

Can also use the MAC address of the system BSSID (Basic Service Set Identifier - this way is not common), getting to know a machine name directly. The MAC address generally given a special registration plate or separated from each other server or device, including wireless network. Advantageous to use ad hoc systems, such as a network connection between two computers, but there are close to the point of access to a working tool.

SSID is the name of a network card or USB card or a PCI card or Wireless Router. SSID is just a name to give a sign of where the name of a device is located. BSSID is the other name of the SSID, the SSID provided by the user such as 'pcsaya' on a computer that is being used and other computers made the name 'pckamu'. While BSSID MAC address using the database. When a wireless connection to connect to each other, both must use the setup adhoc. If there is room around the Access Point device, need to be reminded to change the frequency band so as not to compete with each other strong signals emanating within a room. 

Infrastructure systems require a special tool or can function as an access point via the software when you use a type of wireless network adapter with a PCI device. Lig HUB network comprises a network, but in the access point device provides a central network enabling signal (TV) radio to be accepted by another computer. To illustrate the connection to the infrastructure network access point minimum has a wireless network at a time Sebua am looking for places where other computers / receiving signals to supply networks must be interconnected. System access point (AP) is the most widely used, because each computer wishing to connect to the network can easily hear the broadcast from Access Point. 
Access Point that provides signs that this is a place to have a Wi-Fi and continuously transmits its name (SSID) and can be received by other computers to be known. The difference with the cable network HUB, HUB by a cable, but do not have a name (SSID). Although access point does not use a network cable, but it must have a name that is the name of the SSID.

The advantages of this system are:

1. a PA system in the PC would much easier settings. client computer can not know that there is a hardware industry in a room or a computer that transmits signals from the access point, so he could enter a network.

2. The second advantage of using specialized hardware and therefore not need a PC that runs 24 hours to earn online. Many hardware access point may be connected to a hub or a LAN. And users of wireless computers can connect to a network line.

3. Security system on the AP model is more assured. For a hardware security features of Access Point have some features, such as conducting an IP block, restrict users to port and others.