What is Wi-fi??

---

Kontributor:

Nur baiti

---

DEFINITION OF WIRELESS FIDELITY (Wi-Fi)

Wireless Fedility (Wi-Fi) is a technology to exchange data using radio waves (wirelessly) by utilizing various electronic devices. Required electronic equipment such as computers, smartphones, or tablets to connect in computer networks, including the internet, via Wireless Fedility (Wi-Fi). To be able to connect with Wireless Fedility (Wi-Fi), electronic devices must be in a wireless network access point (hotspot). In a Wireless Fedility (Wi-Fi) network, usually access points have a range of up to 20 meters indoors, and some are further out for Wireless Fedility (Wi-Fi) outdoors. Wireless Fedility (Wi-Fi) in general, to be able to connect with an electronic device, Wireless Fedility (Wi-Fi) use radio frequency waves in the range of 2.4 GHz up to 5 GHz.

Specification

Wireless Fedility (Wi-Fi) is designed based on the (Institute of Electrical and Electronics Engineers) 802.11 spefisication. Now there are four variations of 802.11, namely:

802.11a

802.11b

802.11g

802.11n

Specification b is the first Wi-Fi product. The variations of g and n are among the products that have the most sales in 2005.

Spesification	Speed	Frequency Band	Compatibble with
802.11b	11 Mb/s	̴ 2.4 GHz	b
802.11a	54 Mb/s	̴ 5 GHz	a
802.11g	54 Mb/s	̴ 2.4 GHz	b, g
802.11n	100 Mb/s	̴ 2.4 GHz	b, g, n

HISTORY OF WIRELESS FIDELITY (Wi-Fi)

Wireless Fedility (Wi-Fi) is a trademark of the Wi-Fi Alliance and the brand name for products that use the IEEE (Institute of Electrical and Electronics Engineers) 802.11 standard family. The history of technology began with the 1985 US Federal Communications Commission’s decision to release a GSM band for unlicensed use. In 1991, the NCR Corporation with AT & T found an 802.11 predecessor devoted to the cashier system. The first wireless products are under the name of WaveLAN. Victor Hayes was dubbed as “Mr Wi-Fi”. He is involved in the design of IEEE’s first standard.

There is a history of the development of Wireless Fedility (Wi-Fi) which can be briefly spelled out in the following points:

• 1997 : established a wireless network named 802.11 by the IEEE (Institute of Electrical and Electronics Engineers). Equipment that comlies with the 802.11 standard works on a 2.4 GHz frequency, and a maximum theoretical throughput rate of 2Mbps.
  
  
• 1999 : appears wireless B with data transfer rates of 11 Mbps. But it still has a weakness, the operating frequency is in the figure of 2.4 GHz, which is also widely used by the frequency of household appliances such as microwave ovens, so easily disturbed signal.
  
  
• 2003 : appears wireless G with a maximum data transfer rate of 54 Mbps. It still operates in a 2.4 GHz frequency. Because wireless G is set to be compatible with wireless B then people can use wireless B to connect with wireless G devices or routers.
  
  
• 2009 : appears wireless N, supports data transfer rates up to 300 Mbps (2 antennas) or 450 Mbps (3 antennas). Rich wider than wireless G signal.
  
  
• 2014 : appears wireless AC that has a speed of 500Mb / s – 1 Gb / s. operates at a 5GHz frequency.

ADVANTAGES AND DISADVANTAGES OF WIRELESS FIDELITY (Wi-Fi)

Advantage

Why use Wireless Fedility (Wi-Fi)? Because Wireless Fedility (Wi-Fi) can help internet users to finishing their job easier and more efficient. In addition Wireless Fedility (Wi-Fi) has the following advantages:

1. Connecting Device Into Network
   Different with the LAN cable network which limited use, Wireless Fedility (Wi-Fi) can be used in many computers without increasing the number of cables. That way, Wireless Fedility (Wi-Fi) allows many users to connect to the network at once.
   
   
2. Sharing Data Between Devices
   Suppose you have two electronic devices, then want to move data on one of them to another device. Wireless Fedility (Wi-Fi) can be used for this, so data cables are no longer needed and cause more practical and efficient work.
   
   
3. Modem From Smartphone
   Indeed, with the Wireless Fedility (Wi-Fi), a smartphone can connect to the internet so that users no longer needed to use data packet. But not only that, if your smartphone supports wireless devices, then you can make the smartphone as a modem. This is especially useful if you are traveling to a place where Wireless Fedility (Wi-Fi) is not available. If you have enough data packets, then when you want to access the internet through a laptop for example, you can enable the smartphone as a modem that uses Wireless Fedility (Wi-Fi) signal to connect to the laptop.
   
   
4. Internet Speed More Fast
   This certainly can be understood by smartphone users. In contrast to when accessing the internet via mobile networks are sometimes fast sometimes slow depending on the presence of signals, usually the speed of internet access using Wireless Fedility (Wi-Fi) more secure speed. One of the indications is that you can stream uninterrupted video streaming, faster document downloads, access that does not require loading.
   
   
5. Support The Smoothness Of Business
   Installation of Wi-Fi connect means to make customers feel at home and support your business with social media share. This will create a symbiotic relationship mutualism or mutual benefit between the business with the customer. Businessperson who are sensitive to the strategic opportunities of increasing consumers, will seek the installation of internet wifi service. It is certain that young people and anyone who likes to spend time outdoors to build a social life outdoors would love to come to a public place with Wi-Fi connect facilities. In addition they often check in some social media they have to update the location where they are located, such as mall, boutiques, restaurant, café, or your store.
   What happened? Surely someone else outside your target market will be attracted to your business premises without being planned instead? This can be a marketing strategy as well as branding that is more cost effective than advertising. Increasingly the internet users and in accordance with the needs of the internet network, the more people are looking for a place to freely use Wi-Fi. This is what can be used to attract customers to your business place. Installation of Wi-Fi connect will help the development of business, because it can do the campaign more quickly and easily to be able to get a wider consumer without having to do promotion in a conventional way. Free Wi-Fi facility is guaranteed to have the ability to increase consumer satisfaction. From that satisfaction then your business reputation will also be well known in the eyes of the public.

Disadvantage

The disadvantages when using Wireless Fedility (Wi-Fi):

1. Less secure because Wi-Fi networks can be tapped
   Wi-Fi network is public, so it can be entered by anyone, the danger is that it can be entered by users who have negative interests. It is not like a network cable that protected its network with special connection using cable. Although Wi-Fi network can be reinforced with passwords installed, but do not rule out the existence of irresponsible people who leak passwords or hacked unknown person.
   
   
2. Expensive network devices
   Indeed when compared with wireless / Wifi network cable devices is more expensive but by using this network is easier and practical.
   
   
3. Signal strength may decrease when weather conditions are poor
   
   
4. Signal strength is affected by the physical environment and obstructions, such as walls and glass.

HOW WIRELESS FIDELITY (Wi-Fi) WORK

Simply put, Wireless Fedility (Wi-Fi) works by utilizing radio waves. Various data requested or transmitted by users flew through the air using radio waves. In order to translate data or documents sent through these radio waves. A computer must have a wireless adapter so that it is connected with Wireless Fedility (Wi-Fi).

Radio waves in the form of these signals are then sent to the router that serves as a decoder (code translator). After than translated, the data is sent to the internet network by utilizing Ethernet connection. Wireless Fedility (Wi-Fi) networks wor both ways, each data received over the internet at the same time passing through the router to to be coded by it on each data packet, then transmitted again in the form of radio signals received by the wireless computer adapter.

In order to connect with a Wi-Fi LAN, a computer needs to be equipped with a wireless network interface controller. Combined computers and interface controllers are called stations. All stations share one radio frequency communication channel. Transmission on this channel is received by all stations within range. The hard ware does not tell the user that the transmission was received successfully and this is called the best delivery mechanism. A carrier wave is used to send data in packets, called “Ethernet frames”. Each station continues to connect with radio frequency communication channels to pick up available transmission.

Internet Access

A Wi-Fi tool can connect to the Internet when it is within range of a wireless network connected to the internet. The coverage of one or more access points (interconnection) – called a hotspot – can cover an area of several rooms up to several square miles. Coverage in a wider area requires multiple access points with overlapping coverage. Outside public Wi-Fi technology successfully applied in wireless mesh network in London, United Kingdom. Wi-Fi provides services in private homes, large streets and shops, as well a public spaces via free or paid free Wi-Fi hotspots. Organizations and business, such as airports, hotels, and restaurants, usually provide free hotspots to attract visitors. Enthusiastic users or authorities who want to service or even promote business in certain places sometimes provide free Wi-Fi access. The growing age of changing the internet from the previous only tertiary needs, now seems to have become a primary need. That’s why then many businesspeople use the Wireless Fedility (Wi-Fi) so that customers can ejoy more time in theirs restaurant / café.

Routers involving digital subscriber line modems or cable modems and Wi-Fi access points, typically installed in homes and others buildings, provide internet access and interconnect to all devices connected to the router wirelessly or wired. With the emergence of MiFi and WiBro (Portable Wi-Fi routers), users can easily create their own Wi-Fi hotspot connected to the internet via mobile networks. Now, Android, iOS (iPhone) and Symbian devices are capable or creating wireless connections. Wireless Fedility (Wi-Fi) also connects places that normally do not have network access, such as kitchens and garden houses.

The high public interest – especially among the internet community – uses Wi-Fi technology due to at least two factors. First, easy access. That is, users in one area can access the internet simultaneously without the need to be bothered with a cable. Consequently, users who want to surf or browse news and information on the internet, simply bring a PDA (Pocket Digital Assistance) or a Wi-Fi enabled laptop to a place where there are access points or hotspot. The proliferation of hotspots in those places – built by telecom operators, internet services providers and even individuals – is triggered by a second factor, which is due to the relatively low cost of construction or only about $300. Increasing quantity of internet users based on increasingly symptomatic Wi-Fi technology in various parts of the world has encouraged internet service providers (ISPs) to build hotspots in major cities of the world.

Equipment or Tools Needed to Create a Wireless Network:

1. Access Point
   The most common tool used to connect local networks with wireless/ wireless network. With this tool an internet connection from where internet users are transmitted or transmitted over radio waves.
   
   
2. Omni Antenna
   This tool is used to expand wireless or Wi-Fi network.
   
   
3. Pigtail Cable / Jumper Cable
   This tool is necessary to connect between omni antenna with access point.
   
   
4. POE (Power Over Ethernet)
   This tool functions to funnel the current through an Ethernet cable or UPT / STP cable, with this tool then you do not need to bother anymore stalling the poer cable to the top of the tower, more practical and efficient.
   
   
5. UTP/STP Cable
   It is required to connect between the access point with the wired network on your local LAN, so below it can be plugged into Gateway / Router computer or to Hub/Switch.
   
   
6. Lightning Arrester
   This tool role as a lightning Arrester. The function is distribute overloaded electric current lightning strike to cable or your device (grounding).
   
   
7. Tower
   It is used for maximum coverage area, by raising the omni external antenna to high place by putting tower to capture long distance wifi signal.