Wifi (/ iconwaɪfaɪ /, also written WiFi or WiFi) is a well-known technology that utilizes electronic devices to exchange data wirelessly (using radio waves) over a computer network, including high-speed Internet connection. Wi-Fi Wi-Fi Alliance defines as "the product of wireless local area networks (WLAN) based on any standard Institute of Electrical and Electronics Engineers (IEEE) 802.11". However, since most of today's WLANs based on these standards, the term "Wi-Fi" is used in the common English language as a synonym for "WLAN".
A tool that can use Wi-Fi (such as a personal computer, video game console, smart phone, tablet, or digital audio player) can be connected to the network resources such as the Internet through a wireless network access point. Access point (atauhotspot) as it has a range of about 20 meters (65 feet) in the room and, more broadly outdoors. Hotspot coverage can cover an area of the room with walls that block radio waves or a few square miles - this can be done by using multiple access points overlap.
"Wi-Fi" is a trademark of the Wi-Fi Alliance and the brand name for products using the IEEE 802.11 family of standards. Only products that complete the Wi-Fi interoperability certification testing the Wi-Fi Alliance are allowed to use the name and trademark "Wi-Fi CERTIFIED".
Wi-Fi has a history of changing security. First encryption systems, WEP, proved to be easily penetrated. Higher quality protocols, WPA and WPA2, then added. However, an optional feature that was added in 2007 called Wi-Fi Protected Setup (WPS), has loopholes that allow an attacker to get WPA or WPA2 password of the remote router within a few hours. A number of companies advised to disable WPS. Wi-Fi Alliance since the update test plans and certification programs to ensure that all new equipment certified immune from attack AP PIN hard.
History Main article: History of IEEE 802.11
History of 802.11 technology originated in the US Federal Communications Commission's decision in 1985 to release a band GSM for use without a license. [3] In 1991, NCR Corporation together AT & T found the predecessor 802.11 intended for cashier systems. The first wireless products are under the name WaveLAN.
Vic Hayes dubbed the "Father of Wi-Fi". He was involved in the design of the first IEEE standard.
A large number of patents by many companies use the 802.11 standard. In 1992 and 1996, an Australian organization CSIRO get a patent for a method that would be used in Wi-Fi to remove signal interference. [7] In April 2009, 14 technology companies agreed to pay $ 250 million to CSIRO for violating patents them. It encourages Wi-Fi is touted as Australia's findings, although it has become a topic of some controversy. CSIRO won a lawsuit worth $ 220 million for patent infringement in 2012 Wi-Fi requesting global firms in the United States pay the licensing rights to CSIRO worth $ 1 billion.
In 1999, the Wi-Fi Alliance was formed as a trade association for holding the Wi-Fi is a trademark used by many products.
Name
The term Wi-Fi, first used commercially in August 1999, triggered by a brand consulting firm called Interbrand Corporation. Wi-Fi Alliance hired Interbrand to specify the name of the "easier said than 'IEEE 802.11b Direct Sequence' '. Belanger also said that Interbrand creates a Wi-Fi as a play on the Hi-Fi (high fidelity); they also designed the Wi-Fi logo.
Wi-Fi Alliance made a perfunctory advertising slogan "The Standard for Wireless Fidelity" and was used shortly after the Wi-Fi brand created. Because the slogan, people mistakenly think that Wi-Fi is short for "Wireless Fidelity" despite the fact that instead.
Logo yin-yang Wi-Fi interoperability certification indicates a product.
Technology of non-Wi-Fi needed for of points remain as Motorola Canopy usually called fixed wireless. Alternative wireless technologies include mobile phone standards such as 2G, 3G, or 4G.
Wi-Fi Certification
See also: Wi-Fi Alliance
IEEE does not test equipment to meet their standards. Nonprofit Wi-Fi Alliance was founded in 1999 to fill this gap - to establish and encourage interoperability and compatibility standards, as well as promoting the wireless local area network technology. In 2010, the Wi-Fi Alliance is composed of more than 375 companies worldwide. Wi-Fi Alliance to encourage the use of the brand to the Wi-Fi technology based on the IEEE 802.11 standards of the Institute of Electrical and Electronics Engineers. It includes a wireless local area network connection (WLAN) connectivity tool-to-tool (such as Wi-Fi Peer to Peer or Wi-Fi Direct), personal area networks (PAN), local area network (LAN), and even the number of connections wide area network (WAN) is limited. The company manufactures the Wi-Fi Alliance membership, whose products successfully passed the certification process, entitled marking the product with the Wi-Fi logo.
Specifically, the certification process requires compliance with the IEEE 802.11 radio standards, WPA and WPA2 security standdar, and EAP authentication standard. Optional certification includes testing of the draft IEEE 802.11 standard, the interaction with cell phone technology in convergent devices, and security features, multimedia, and energy savings.
Not all Wi-Fi equipment is sent to get certified. Lack of Wi-Fi certification does not mean that a tool is not compatible with other Wi-Fi tool. If the tool is qualified or semi-compatible, Wi-Fi Alliance does not need to comment on their mention as a means of Wi-Fi, [need reference] although technically only approved certified tool. Terms such as Super Wi-Fi, which was initiated by the Federal Communications Commission (FCC) of the United States to describe the UHF TV band network plan in the United States, can be approved or not.
Logo Wi-Fi signal
Use
To connect with LAN Wi-Fi, a computer needs to be equipped with a wireless network interface controller. Combined computer and interface controller called the station. All stations share a radio frequency communication channel. Transmission in this channel received by all stations within range. Hardware does not notify the user that the transmission is successfully received and referred to the best delivery mechanism. A carrier wave is used to send data in packets, called "Ethernet frame". Each station continuously connected to a radio frequency communication channel to take the available transmission.
Internet Access
A Wi-Fi tool can connect to the Internet when within range of a wireless network connected to the Internet. Coverage of one access point or more (interconnection) - called hotspots - can cover an area of several rooms up to several square miles. Coverage in a larger area requires several access points with overlapping coverage. Public Wi-Fi technology outdoors successfully applied in wireless mesh networks in London, United Kingdom.
Wi-Fi provides services in private homes, major streets and shops, and public spaces via Wi-Fi hotspots are installed free or paid. Organizations and businesses, such as airports, hotels, and restaurants, usually provide free hotspots to attract visitors. Users are enthusiastic or authorities who want to give service or even to promote business in certain places sometimes provide free Wi-Fi access.
Router involving digital subscriber line modem or cable modem and WI-Fi access points, usually installed in homes and other buildings, providing Internet access danantarjaringan to all devices connected to the router wirelessly or wired. With the emergence of MiFi and WiBro (portable Wi-Fi router), the user can easily create a Wi-Fi hotspot its own that are connected to the Internet via cellular networks. Now, equipment Android, Bada, iOS (iPhone), and Symbian is able to create a wireless connection. [24] also connect Wi-Fi places that normally do not have access to the network, such as the kitchen and home gardens.
Wi-Fi city
Further information: wireless jarignan city
Wi-Fi access point open
In the early 2000s, many cities around the world announced plans to build a city-wide Wi-Fi network. Examples of successful businesses that Mysore in 2004 became the first Wi-Fi city in India and the second in the world after Jerusalem. WiFiyNet company founded several hotspots in Mysore, which covers the entire city and surrounding villages.
In 2005, Sunnyvale, California, became the first city in the United States that provide free Wi-Fi with the scope of the city, and Minneapolis earn $ 1.2 million per year for its service providers.
In May 2010, the Mayor of London, Great Britain, Boris Johnson promised to build a Wi-Fi network that covers the whole of London in 2012. A number of boroughs, including Westminster and Islington already have Wi-Fi coverage is open wide.
Officials in the South Korean capital, Seoul, trying to provide free Internet access at more than 10,000 locations around the city, including public open space, the main road, and densely populated residential areas. Seoul will be handed operation to KT, LG Telecom and SK Telecom. These companies will invest $ 44 million for this project, which will be completed in 2015.
Wi-Fi campus
Many traditional campus in the United States have coverage Wi-Fi wireless Internet patchy. Carnegie Mellon University to build the first sekampus Internet network called Wireless Andrew at its Pittsburgh campus in 1993 before the Wi-Fi brand appears.
In 2000, Drexel University, Philadelphia became the first major university in the United States who have wireless Internet access throughout the campus.
Direct communication between computers
Wi-Fi also allows direct communication from one computer to another without going through the access point. This is called the transmission of ad hoc Wi-Fi. Ad hoc network mode nirkabelini popularized by handheld game console multiplayer, such as the Nintendo DS, Playstation Portable, digital cameras, and other consumer electronics equipment. A number of tools are also able to share its Internet connection using an ad-hoc, become a hotspot or "virtual router".
Similarly, the Wi-Fi Alliance to promote a specification called Wi-Fi Direct for file transfer and sharing of media through search methodology and abru security. Wi-Fi Direct was launched in October 2010.
Specification
Wi-Fi is designed based on the IEEE 802.11 specification. Today there are four variations of 802.11, namely:
• 802.11a
• 802.11b
• 802.11g
• 802.11n
Specifications b is the first Wi-Fi products. Variations g and n is one product that has the highest sales in 2005.
Specifications Wi-Fi
Specifications Frequency Speed
Band Matches
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
In many parts of the world, the frequencies used by Wi-Fi, users are not required to obtain permission from the local regulator (eg, the Federal Communications Commission in the US). 802.11a uses a higher frequency and therefore its range is narrower, other things being equal.
Wi-Fi version of the most extensive in the US market today (based on the IEEE 802.11b / g) operates at 2.400 GHz to 2483.50 GHz. With so allow operations in 11 channels (each 5 MHz), centered on the following frequencies:
• Channel 1 to 2.412 GHz;
• Channel 2 to 2.417 GHz;
• Channel 3 to 2.422 GHz;
• Channel 4 to 2.427 GHz;
• Channel 5 to 2.432 GHz;
• Channel 6 to 2.437 GHz;
• Channel 7 to 2.442 GHz;
• Channel 8 to 2.447 GHz;
• Channel 9 to 2.452 GHz;
• Channel 10 to 2.457 GHz;
• Channel 11 to 2.462 GHz
Technically operational, Wi-Fi is one variant of communication and information technology that works on the network and the WLAN (wireless local area network). In other words, Wi-Fi is a trademark certification granted to the telecommunications equipment manufacturers (internet) are working on a WLAN network and already meets the required quality interoperates capacity.
Technology-based Wi-Fi internet created and developed a group of US engineers who worked at the Institute of Electrical and electronis Engineers (IEEE) is based on the technical standards numbered 802.11b, 802.11a and 802.16. Wi-Fi devices is not only able to work on WLAN networks, but also in the network Wireless Metropolitan Area Network (WMAN).
Because the device with the technical standard 802.11b WLAN devices are intended for use at a frequency of 2.4 GHz or commonly called ISM (Industrial, Scientific and Medical). As for the technical standards of 802.11a and 802.16 WMAN intended for the device or also called Wi-Max, which works around the 5 GHz frequency band.
Especially of high public interest in the community Internet-- using Wi-Fi technology due to at least two factors. First, the ease of access. That is, users in one area can access the Internet simultaneously without the need to be bothered with cables.
Consequently, users who want to surf or browse news and information on the Internet, just bring a PDA (Pocket Digital Assistance) or Wi-Fi enabled laptop to a place where there is an access point or hotspot.
The proliferation of hotspots in such places, who built by telecommunications operators, Internet service providers and even the perorangan-- triggered a second factor, namely because of the relatively low cost of construction or just around 300 dollars US.
Increasing the quantity of Internet users based on Wi-Fi technology that is increasingly implicated in various parts of the world, has been pushing Internet service providers (ISPs) to build hotspots in major cities of the world.
Some observers have even been predicted in 2006, there will be as many as 800,000 hotspots in European countries, 530,000 in the United States and one million in the Asian countries.
Total income earned US and European countries of Internet business based Wi-Fi technology by the end of 2003 was estimated at 5.4 trillion US dollars, an increase of 33 billion US dollars from 2002 (www.analysys.com).
Wi-Fi Hardware
Wi-Fi in the form of PCI
Hardware Wi-Fi is available in the market currently exists in the form of:
• PCI
• USB
• PCMCIA
• Compact Flash
Wi-fi in the form of a USB
Fashion Access Wi-Fi Connection
There are two modes of access Wi-Fi connection, ie
Ad-Hoc
This connection mode is a mode where multiple computers are connected directly, or better known as Peer-to-Peer. The advantage, cheaper and more practical when connected only 2 or 3 computers, without having to buy an access point.
Infrastructure
Using the Access Point that serves as data traffic, allowing many client can connect to each other through a network (Network).
The popularity of Wi-Fi
In Indonesia alone, the use of Internet-based Wi-Fi has started implicated in several major cities. In Jakarta, for example, the maniacs who are surfing the Internet while waiting for the plane take off at the airport waiting room, it is not a strange thing.
The same phenomenon is seen in various cafes, just as the Starbucks cafe and La Moda Cafe in Plaza Indonesia, Coffee Club Senayan, and Cafe Coffee Bean in Cilandak Town Square-- where visitors can open the Internet to see the artist's political news or the latest gossip while sipping hot cappucino .
Today, business phone based VoIP (Voice over Internet Protocol) also has Wi-Fi technology, which calls routed through the WLAN network. The application is named VoWi-FI (Voice over Wi-Fi).
Some time ago, the latest technical standards created by the IEEE has been able to support the operation of streaming video services. Even predicted, will be made cards (cards) based Wi-Fi technology that can be inserted into electronic equipment, ranging from digital cameras to video game consoles (ITU News 8/2003).
Based on the above explanation, it can be concluded that the business users and the quantity of Wi-Fi technology is likely to increase, and economically it has a positive impact on the national economy of a country, including Indonesia.
Nevertheless, the government should address the phenomenon wisely and carefully. Because the technologically --baik frequency band of 2.4 GHz and 5 GHz-- which became operational container technology, Wi-Fi is not free from limitations (Kompas, 02/05/2004).
Because the users in a new area can take advantage of this wireless Internet system with optimal, if all devices used in the area using a uniform transmit power and limited.
If these prerequisites are not heeded, will surely occur harmful interference between devices is not just Internet users, but also with the other telecommunications systems.
If the interference persists because users want is superior to other users and the lack of understanding of the limitations of the technology, in the end will make the frequency band of 2.4 GHz and 5 GHz can not be used optimally.
Another limitation of the wireless frequency band (2.4 GHz in particular) is because it is also used for ISM (industrial, science and medical).
Consequently, the use of radio communications or other telecommunications device that works on the frequency band that should be ready to accept interference from ISM devices, as stated in S5.150 of the Radio Regulations.
In ITU-R SM.1056, also informed ISM device characteristics that are essentially aimed at preventing interference, both between the ISM and the telecommunication device sharing.
The same recommendation asserts that every member of the ITU-free set of administrative requirements and rules of law relating to mandatory power restrictions.
Recognizing the limitations and impacts that may arise from the use of both the wireless frequency band, various countries and establish regulations that limit the transmit power of the device used.
Safety
Further information: wireless electronic equipment and health
World Health Organization (WHO) states, "there is no risk after exposure to Wi-Fi networks and long-term low-level," and the United Kingdom Health Protection Agency reported that exposure to Wi-Fi for a year "just as exposed to radiation from mobile phone calls during the 20 minutes "
A small number of Wi-Fi users have reported health problems after repeated exposure to and use Wi-Fi, although no publication on any impact in double blind studies. A study involving 725 people with electromagnetic hypersensitivity claimed to have found evidence for their claims. A study speculated that "laptop (Wi-Fi mode) on the lap near the testes may lower male fertility" Other studies find that working memory decline among men when exposed to Wi-Fi.
A tool that can use Wi-Fi (such as a personal computer, video game console, smart phone, tablet, or digital audio player) can be connected to the network resources such as the Internet through a wireless network access point. Access point (atauhotspot) as it has a range of about 20 meters (65 feet) in the room and, more broadly outdoors. Hotspot coverage can cover an area of the room with walls that block radio waves or a few square miles - this can be done by using multiple access points overlap.
"Wi-Fi" is a trademark of the Wi-Fi Alliance and the brand name for products using the IEEE 802.11 family of standards. Only products that complete the Wi-Fi interoperability certification testing the Wi-Fi Alliance are allowed to use the name and trademark "Wi-Fi CERTIFIED".
Wi-Fi has a history of changing security. First encryption systems, WEP, proved to be easily penetrated. Higher quality protocols, WPA and WPA2, then added. However, an optional feature that was added in 2007 called Wi-Fi Protected Setup (WPS), has loopholes that allow an attacker to get WPA or WPA2 password of the remote router within a few hours. A number of companies advised to disable WPS. Wi-Fi Alliance since the update test plans and certification programs to ensure that all new equipment certified immune from attack AP PIN hard.
History Main article: History of IEEE 802.11
History of 802.11 technology originated in the US Federal Communications Commission's decision in 1985 to release a band GSM for use without a license. [3] In 1991, NCR Corporation together AT & T found the predecessor 802.11 intended for cashier systems. The first wireless products are under the name WaveLAN.
Vic Hayes dubbed the "Father of Wi-Fi". He was involved in the design of the first IEEE standard.
A large number of patents by many companies use the 802.11 standard. In 1992 and 1996, an Australian organization CSIRO get a patent for a method that would be used in Wi-Fi to remove signal interference. [7] In April 2009, 14 technology companies agreed to pay $ 250 million to CSIRO for violating patents them. It encourages Wi-Fi is touted as Australia's findings, although it has become a topic of some controversy. CSIRO won a lawsuit worth $ 220 million for patent infringement in 2012 Wi-Fi requesting global firms in the United States pay the licensing rights to CSIRO worth $ 1 billion.
In 1999, the Wi-Fi Alliance was formed as a trade association for holding the Wi-Fi is a trademark used by many products.
Name
The term Wi-Fi, first used commercially in August 1999, triggered by a brand consulting firm called Interbrand Corporation. Wi-Fi Alliance hired Interbrand to specify the name of the "easier said than 'IEEE 802.11b Direct Sequence' '. Belanger also said that Interbrand creates a Wi-Fi as a play on the Hi-Fi (high fidelity); they also designed the Wi-Fi logo.
Wi-Fi Alliance made a perfunctory advertising slogan "The Standard for Wireless Fidelity" and was used shortly after the Wi-Fi brand created. Because the slogan, people mistakenly think that Wi-Fi is short for "Wireless Fidelity" despite the fact that instead.
Logo yin-yang Wi-Fi interoperability certification indicates a product.
Technology of non-Wi-Fi needed for of points remain as Motorola Canopy usually called fixed wireless. Alternative wireless technologies include mobile phone standards such as 2G, 3G, or 4G.
Wi-Fi Certification
See also: Wi-Fi Alliance
IEEE does not test equipment to meet their standards. Nonprofit Wi-Fi Alliance was founded in 1999 to fill this gap - to establish and encourage interoperability and compatibility standards, as well as promoting the wireless local area network technology. In 2010, the Wi-Fi Alliance is composed of more than 375 companies worldwide. Wi-Fi Alliance to encourage the use of the brand to the Wi-Fi technology based on the IEEE 802.11 standards of the Institute of Electrical and Electronics Engineers. It includes a wireless local area network connection (WLAN) connectivity tool-to-tool (such as Wi-Fi Peer to Peer or Wi-Fi Direct), personal area networks (PAN), local area network (LAN), and even the number of connections wide area network (WAN) is limited. The company manufactures the Wi-Fi Alliance membership, whose products successfully passed the certification process, entitled marking the product with the Wi-Fi logo.
Specifically, the certification process requires compliance with the IEEE 802.11 radio standards, WPA and WPA2 security standdar, and EAP authentication standard. Optional certification includes testing of the draft IEEE 802.11 standard, the interaction with cell phone technology in convergent devices, and security features, multimedia, and energy savings.
Not all Wi-Fi equipment is sent to get certified. Lack of Wi-Fi certification does not mean that a tool is not compatible with other Wi-Fi tool. If the tool is qualified or semi-compatible, Wi-Fi Alliance does not need to comment on their mention as a means of Wi-Fi, [need reference] although technically only approved certified tool. Terms such as Super Wi-Fi, which was initiated by the Federal Communications Commission (FCC) of the United States to describe the UHF TV band network plan in the United States, can be approved or not.
Logo Wi-Fi signal
Use
To connect with LAN Wi-Fi, a computer needs to be equipped with a wireless network interface controller. Combined computer and interface controller called the station. All stations share a radio frequency communication channel. Transmission in this channel received by all stations within range. Hardware does not notify the user that the transmission is successfully received and referred to the best delivery mechanism. A carrier wave is used to send data in packets, called "Ethernet frame". Each station continuously connected to a radio frequency communication channel to take the available transmission.
Internet Access
A Wi-Fi tool can connect to the Internet when within range of a wireless network connected to the Internet. Coverage of one access point or more (interconnection) - called hotspots - can cover an area of several rooms up to several square miles. Coverage in a larger area requires several access points with overlapping coverage. Public Wi-Fi technology outdoors successfully applied in wireless mesh networks in London, United Kingdom.
Wi-Fi provides services in private homes, major streets and shops, and public spaces via Wi-Fi hotspots are installed free or paid. Organizations and businesses, such as airports, hotels, and restaurants, usually provide free hotspots to attract visitors. Users are enthusiastic or authorities who want to give service or even to promote business in certain places sometimes provide free Wi-Fi access.
Router involving digital subscriber line modem or cable modem and WI-Fi access points, usually installed in homes and other buildings, providing Internet access danantarjaringan to all devices connected to the router wirelessly or wired. With the emergence of MiFi and WiBro (portable Wi-Fi router), the user can easily create a Wi-Fi hotspot its own that are connected to the Internet via cellular networks. Now, equipment Android, Bada, iOS (iPhone), and Symbian is able to create a wireless connection. [24] also connect Wi-Fi places that normally do not have access to the network, such as the kitchen and home gardens.
Wi-Fi city
Further information: wireless jarignan city
Wi-Fi access point open
In the early 2000s, many cities around the world announced plans to build a city-wide Wi-Fi network. Examples of successful businesses that Mysore in 2004 became the first Wi-Fi city in India and the second in the world after Jerusalem. WiFiyNet company founded several hotspots in Mysore, which covers the entire city and surrounding villages.
In 2005, Sunnyvale, California, became the first city in the United States that provide free Wi-Fi with the scope of the city, and Minneapolis earn $ 1.2 million per year for its service providers.
In May 2010, the Mayor of London, Great Britain, Boris Johnson promised to build a Wi-Fi network that covers the whole of London in 2012. A number of boroughs, including Westminster and Islington already have Wi-Fi coverage is open wide.
Officials in the South Korean capital, Seoul, trying to provide free Internet access at more than 10,000 locations around the city, including public open space, the main road, and densely populated residential areas. Seoul will be handed operation to KT, LG Telecom and SK Telecom. These companies will invest $ 44 million for this project, which will be completed in 2015.
Wi-Fi campus
Many traditional campus in the United States have coverage Wi-Fi wireless Internet patchy. Carnegie Mellon University to build the first sekampus Internet network called Wireless Andrew at its Pittsburgh campus in 1993 before the Wi-Fi brand appears.
In 2000, Drexel University, Philadelphia became the first major university in the United States who have wireless Internet access throughout the campus.
Direct communication between computers
Wi-Fi also allows direct communication from one computer to another without going through the access point. This is called the transmission of ad hoc Wi-Fi. Ad hoc network mode nirkabelini popularized by handheld game console multiplayer, such as the Nintendo DS, Playstation Portable, digital cameras, and other consumer electronics equipment. A number of tools are also able to share its Internet connection using an ad-hoc, become a hotspot or "virtual router".
Similarly, the Wi-Fi Alliance to promote a specification called Wi-Fi Direct for file transfer and sharing of media through search methodology and abru security. Wi-Fi Direct was launched in October 2010.
Specification
Wi-Fi is designed based on the IEEE 802.11 specification. Today there are four variations of 802.11, namely:
• 802.11a
• 802.11b
• 802.11g
• 802.11n
Specifications b is the first Wi-Fi products. Variations g and n is one product that has the highest sales in 2005.
Specifications Wi-Fi
Specifications Frequency Speed
Band Matches
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
In many parts of the world, the frequencies used by Wi-Fi, users are not required to obtain permission from the local regulator (eg, the Federal Communications Commission in the US). 802.11a uses a higher frequency and therefore its range is narrower, other things being equal.
Wi-Fi version of the most extensive in the US market today (based on the IEEE 802.11b / g) operates at 2.400 GHz to 2483.50 GHz. With so allow operations in 11 channels (each 5 MHz), centered on the following frequencies:
• Channel 1 to 2.412 GHz;
• Channel 2 to 2.417 GHz;
• Channel 3 to 2.422 GHz;
• Channel 4 to 2.427 GHz;
• Channel 5 to 2.432 GHz;
• Channel 6 to 2.437 GHz;
• Channel 7 to 2.442 GHz;
• Channel 8 to 2.447 GHz;
• Channel 9 to 2.452 GHz;
• Channel 10 to 2.457 GHz;
• Channel 11 to 2.462 GHz
Technically operational, Wi-Fi is one variant of communication and information technology that works on the network and the WLAN (wireless local area network). In other words, Wi-Fi is a trademark certification granted to the telecommunications equipment manufacturers (internet) are working on a WLAN network and already meets the required quality interoperates capacity.
Technology-based Wi-Fi internet created and developed a group of US engineers who worked at the Institute of Electrical and electronis Engineers (IEEE) is based on the technical standards numbered 802.11b, 802.11a and 802.16. Wi-Fi devices is not only able to work on WLAN networks, but also in the network Wireless Metropolitan Area Network (WMAN).
Because the device with the technical standard 802.11b WLAN devices are intended for use at a frequency of 2.4 GHz or commonly called ISM (Industrial, Scientific and Medical). As for the technical standards of 802.11a and 802.16 WMAN intended for the device or also called Wi-Max, which works around the 5 GHz frequency band.
Especially of high public interest in the community Internet-- using Wi-Fi technology due to at least two factors. First, the ease of access. That is, users in one area can access the Internet simultaneously without the need to be bothered with cables.
Consequently, users who want to surf or browse news and information on the Internet, just bring a PDA (Pocket Digital Assistance) or Wi-Fi enabled laptop to a place where there is an access point or hotspot.
The proliferation of hotspots in such places, who built by telecommunications operators, Internet service providers and even the perorangan-- triggered a second factor, namely because of the relatively low cost of construction or just around 300 dollars US.
Increasing the quantity of Internet users based on Wi-Fi technology that is increasingly implicated in various parts of the world, has been pushing Internet service providers (ISPs) to build hotspots in major cities of the world.
Some observers have even been predicted in 2006, there will be as many as 800,000 hotspots in European countries, 530,000 in the United States and one million in the Asian countries.
Total income earned US and European countries of Internet business based Wi-Fi technology by the end of 2003 was estimated at 5.4 trillion US dollars, an increase of 33 billion US dollars from 2002 (www.analysys.com).
Wi-Fi Hardware
Wi-Fi in the form of PCI
Hardware Wi-Fi is available in the market currently exists in the form of:
• PCI
• USB
• PCMCIA
• Compact Flash
Wi-fi in the form of a USB
Fashion Access Wi-Fi Connection
There are two modes of access Wi-Fi connection, ie
Ad-Hoc
This connection mode is a mode where multiple computers are connected directly, or better known as Peer-to-Peer. The advantage, cheaper and more practical when connected only 2 or 3 computers, without having to buy an access point.
Infrastructure
Using the Access Point that serves as data traffic, allowing many client can connect to each other through a network (Network).
The popularity of Wi-Fi
In Indonesia alone, the use of Internet-based Wi-Fi has started implicated in several major cities. In Jakarta, for example, the maniacs who are surfing the Internet while waiting for the plane take off at the airport waiting room, it is not a strange thing.
The same phenomenon is seen in various cafes, just as the Starbucks cafe and La Moda Cafe in Plaza Indonesia, Coffee Club Senayan, and Cafe Coffee Bean in Cilandak Town Square-- where visitors can open the Internet to see the artist's political news or the latest gossip while sipping hot cappucino .
Today, business phone based VoIP (Voice over Internet Protocol) also has Wi-Fi technology, which calls routed through the WLAN network. The application is named VoWi-FI (Voice over Wi-Fi).
Some time ago, the latest technical standards created by the IEEE has been able to support the operation of streaming video services. Even predicted, will be made cards (cards) based Wi-Fi technology that can be inserted into electronic equipment, ranging from digital cameras to video game consoles (ITU News 8/2003).
Based on the above explanation, it can be concluded that the business users and the quantity of Wi-Fi technology is likely to increase, and economically it has a positive impact on the national economy of a country, including Indonesia.
Nevertheless, the government should address the phenomenon wisely and carefully. Because the technologically --baik frequency band of 2.4 GHz and 5 GHz-- which became operational container technology, Wi-Fi is not free from limitations (Kompas, 02/05/2004).
Because the users in a new area can take advantage of this wireless Internet system with optimal, if all devices used in the area using a uniform transmit power and limited.
If these prerequisites are not heeded, will surely occur harmful interference between devices is not just Internet users, but also with the other telecommunications systems.
If the interference persists because users want is superior to other users and the lack of understanding of the limitations of the technology, in the end will make the frequency band of 2.4 GHz and 5 GHz can not be used optimally.
Another limitation of the wireless frequency band (2.4 GHz in particular) is because it is also used for ISM (industrial, science and medical).
Consequently, the use of radio communications or other telecommunications device that works on the frequency band that should be ready to accept interference from ISM devices, as stated in S5.150 of the Radio Regulations.
In ITU-R SM.1056, also informed ISM device characteristics that are essentially aimed at preventing interference, both between the ISM and the telecommunication device sharing.
The same recommendation asserts that every member of the ITU-free set of administrative requirements and rules of law relating to mandatory power restrictions.
Recognizing the limitations and impacts that may arise from the use of both the wireless frequency band, various countries and establish regulations that limit the transmit power of the device used.
Safety
Further information: wireless electronic equipment and health
World Health Organization (WHO) states, "there is no risk after exposure to Wi-Fi networks and long-term low-level," and the United Kingdom Health Protection Agency reported that exposure to Wi-Fi for a year "just as exposed to radiation from mobile phone calls during the 20 minutes "
A small number of Wi-Fi users have reported health problems after repeated exposure to and use Wi-Fi, although no publication on any impact in double blind studies. A study involving 725 people with electromagnetic hypersensitivity claimed to have found evidence for their claims. A study speculated that "laptop (Wi-Fi mode) on the lap near the testes may lower male fertility" Other studies find that working memory decline among men when exposed to Wi-Fi.
