A growing number of electronic devi

A growing number of electronic devices, such as cell phones, PDAs, digital cameras, and video
game consoles, are equipped with wireless circuitry. This rids their owners of the need to
physically connect a device to a computer or a router for communication. For example, with a
wireless-enabled digital camera you can send digital pictures from your camera to your PC, or
directly to a friend via a hotspot over the Internet.
IEEE 802.15 Bluetooth
Named after a Scandinavian king who unified many tribes, the Bluetooth
standard was developed for devices that communicate with each other
within a short range of up to 10 meters (33 feet) in the office, at home, and
in motor vehicles. It transmits voice and data. Bluetooth was later adopted
by IEEE as its 802.15 standard. Typical Bluetooth devices include wireless
keyboards and mice, wireless microphones for cellular phones (especially for
use in cars while driving), wireless headsets for hands-free mobile phone
use, and increasingly, digital entertainment devices. For example, you can
purchase a wrist-worn MP3 player that uses Bluetooth to transmit the music
to earbuds or headphones, avoiding the wires that typically connect a
portable player to headphones. Bluetooth is considered a personal area
network (PAN) technology, because it typically supports a network used by
only one person. Bluetooth uses the 2.4–2.5 GHz radio frequency to
transmit bits at a rate of 1 Mbps.
IEEE 802.16 WiMAX
IEEE 802.16,Worldwide Interoperability for Microwave Access (WiMAX), increases the range and
speed of wireless communication. It might potentially reach up to 110 kilometers (about 70
miles) with a speed of 100 Mbps; however, it typically reaches 13–16 kilometers (8–10 miles).
Experts say that with an investment of no more than $3 billion, WiMAX can cover 98 percent
of American homes. This is a much lower investment than required for laying fiber optic cables.
WiMAX uses licensed radio frequencies of 2–11 GHz. This standard can cover entire metropolitan
areas and provide Internet access to hundreds of thousands of households that either cannot
afford an Internet service or for some reason cannot obtain access. Many municipal governments
wanted to establish such service for a fee or for free. However, this has created a threat to the
business of ISPs, who count on subscriber fees for revenue, because an entire metropolitan area
can become one huge hotspot, and the fees, if any, are collected by the local government rather
than an ISP. Therefore, several states in the United States legislated against municipalitysponsored
networks. However, some cities are using the technology, which enables households
that cannot afford Internet connectivity to have access to this important resource. Philadelphia
was the first American metropolis to do so. The city was exempt from a Pennsylvania law
forbidding municipal networks.
WiMAX is a metropolitan area network (MAN) technology. Figure 6.5 shows how WiMAX
works. A household, office, or public hotspot can use a router to link multiple devices either by
linking directly to a WiMAX base antenna that is linked to the Internet, or by using a relay
antenna that receives the signal and retransmits it to the Internet-linked antenna. If a mobile
user’s equipment included the proper WiMAX communication device, the user could communicate
with the Internet moving at speeds of up to 150 Km/H (about 94 MPH), which enables
convenient use of the Internet while sitting in a moving vehicle (though the driver should not
be going that fast!). An extension of this standard, 802.16e, supports mobile Internet
communication. The telecommunications company HorizonWi-Com started the construction of
802.16e networks in Boston, New York, Philadelphia, Washington, D.C., Baltimore, Pittsburgh,
Buffalo, Richmond, and Cincinnati. The installation was scheduled to be completed by the end
of 2007. Similar efforts have taken place in other countries, notably Pakistan. However, a newer,
special standard dedicated to mobile communications is 802.20.
IEEE 802.20 MBWA
Mobile Broadband Wireless Access (MBWA) functions similarly to cell phone communications,
because it controls communication from stationary towers. The purpose of MBWA is to
provide mobile communication that is compatible with IP services. This should enable worldwide
deployment of affordable, always-on wireless access. The principle is simple: place wireless
routers on towers so that mobile phones can use VoIP and access other Internet resources over
wide areas, and, eventually, globally. MBWA is expected to work at speeds over 1 Mbps, using
licensed radio frequencies below 3.5 GHz. If the standard is successfully implemented globally, it
will reduce subscriber fees significantly and pose severe competition to providers of cell phone
services.
The 802.20 standard is designed to be compatible with 802.11 (Wi-Fi) and 802.15 (Bluetooth).
It can support Internet communication at a moving speed of up to 250 Km/H (156 MPH). MBWA
promises to support practically everything that we now do with telephones and through the
Internet:Web browsing, file transfer, e-mail, VoIP, video telephony and videoconferencing, audio
streaming (such as listening to transmitted music), Web-based gaming, and file sharing. The
technology includes security measures that meet the standards of the U.S. Department of Defense
for protection of sensitive but unclassified information. To a large extent, this standard is still
under development.
Figure 6.6 summarizes relevant features of the 802.xx wireless protocols discussed here.

Hasil (Bahasa Indonesia) 1:

A growing number of electronic devices, such as cell phones, PDAs, digital cameras, and videogame consoles, are equipped with wireless circuitry. This rids their owners of the need tophysically connect a device to a computer or a router for communication. For example, with awireless-enabled digital camera you can send digital pictures from your camera to your PC, ordirectly to a friend via a hotspot over the Internet.IEEE 802.15 BluetoothNamed after a Scandinavian king who unified many tribes, the Bluetoothstandard was developed for devices that communicate with each otherwithin a short range of up to 10 meters (33 feet) in the office, at home, andin motor vehicles. It transmits voice and data. Bluetooth was later adoptedby IEEE as its 802.15 standard. Typical Bluetooth devices include wirelesskeyboards and mice, wireless microphones for cellular phones (especially foruse in cars while driving), wireless headsets for hands-free mobile phoneuse, and increasingly, digital entertainment devices. For example, you canpurchase a wrist-worn MP3 player that uses Bluetooth to transmit the musicto earbuds or headphones, avoiding the wires that typically connect aportable player to headphones. Bluetooth is considered a personal areanetwork (PAN) technology, because it typically supports a network used byonly one person. Bluetooth uses the 2.4–2.5 GHz radio frequency totransmit bits at a rate of 1 Mbps.IEEE 802.16 WiMAXIEEE 802.16, Worldwide Interoperability for Microwave Access (WiMAX), meningkatkan jangkauan dankecepatan komunikasi nirkabel. Itu mungkin berpotensi mencapai hingga 110 kilometer (sekitar 70Miles) dengan kecepatan 100 Mbps; Namun, biasanya mencapai 13-16 kilometer (8-10 mil).Para ahli mengatakan bahwa dengan investasi tidak lebih dari $3 miliar, WiMAX dapat menutupi 98 persenrumah-rumah Amerika. Ini adalah investasi yang jauh lebih rendah dari yang dibutuhkan untuk meletakkan serat optik kabel.Menggunakan WiMAX berlisensi frekuensi radio 2-11 GHz. Standar ini dapat menutupi seluruh metropolitandaerah dan menyediakan akses Internet untuk ratusan ribu rumah tangga yang baik tidakmampu Layanan Internet atau untuk beberapa alasan tidak dapat memperoleh akses. Banyak pemerintah municipalingin membangun seperti layanan untuk biaya atau gratis. Namun, hal ini telah menciptakan sebuah ancaman bagibisnis dari ISP, yang mengandalkan pelanggan biaya untuk pendapatan, karena seluruh wilayah metropolitandapat menjadi salah satu hotspot yang besar, dan biaya, jika ada, yang dikumpulkan oleh pemerintah daerah agakdari ISP. Oleh karena itu, beberapa negara bagian di Amerika Serikat menunjuk terhadap municipalitysponsoredjaringan. Namun, beberapa kota yang menggunakan teknologi, yang memungkinkan rumah tanggayang tidak mampu konektivitas Internet memiliki akses ke sumber daya yang penting ini. Philadelphiaadalah metropolis Amerika pertama untuk melakukannya. Kota ini dibebaskan dari hukum Pennsylvaniamelarang municipal jaringan.WiMAX adalah teknologi jaringan (MAN) wilayah metropolitan. Mencari 6.5 menunjukkan bagaimana WiMAXbekerja. Rumah tangga, kantor, atau hotspot publik dapat menggunakan router untuk menghubungkan beberapa perangkat baik olehmenghubungkan langsung ke antena basis WiMAX yang terhubung ke Internet, atau dengan menggunakan relayantena yang menerima sinyal dan retransmits dengan antena yang terhubung Internet. Jika ponselpengguna peralatan termasuk perangkat komunikasi WiMAX yang tepat, pengguna bisa berkomunikasidengan Internet bergerak pada kecepatan hingga 150 Km/h (sekitar 94 MPH), yang memungkinkannyaman menggunakan Internet sambil duduk dalam kendaraan pindah (meskipun sopir seharusnya tidakpergi secepat itu!). Perpanjangan dari 802.16e ini standar, mendukung mobile Internetkomunikasi. Perusahaan telekomunikasi HorizonWi-Com mulai pembangunan802.16e jaringan di Boston, New York, Philadelphia, Washington DC, Baltimore, Pittsburgh,Buffalo, Richmond, dan Cincinnati. Instalasi dijadwalkan selesai pada akhir2007. Upaya serupa telah terjadi di negara lain, terutama Pakistan. Namun, yang lebih baru,komunikasi khusus didedikasikan untuk ponsel standar adalah 802.20.IEEE 802.20 MBWAFungsi Mobile Broadband Wireless Access (MBWA) mirip komunikasi telepon seluler,karena komunikasi dari stasioner menara. Tujuan MBWA untukmenyediakan komunikasi selular yang kompatibel dengan IP services. Ini harus mengaktifkan di seluruh duniadeployment of affordable, always-on wireless access. The principle is simple: place wirelessrouters on towers so that mobile phones can use VoIP and access other Internet resources overwide areas, and, eventually, globally. MBWA is expected to work at speeds over 1 Mbps, usinglicensed radio frequencies below 3.5 GHz. If the standard is successfully implemented globally, itwill reduce subscriber fees significantly and pose severe competition to providers of cell phoneservices.The 802.20 standard is designed to be compatible with 802.11 (Wi-Fi) and 802.15 (Bluetooth).It can support Internet communication at a moving speed of up to 250 Km/H (156 MPH). MBWApromises to support practically everything that we now do with telephones and through theInternet:Web browsing, file transfer, e-mail, VoIP, video telephony and videoconferencing, audiostreaming (such as listening to transmitted music), Web-based gaming, and file sharing. Thetechnology includes security measures that meet the standards of the U.S. Department of Defensefor protection of sensitive but unclassified information. To a large extent, this standard is stillunder development.Figure 6.6 summarizes relevant features of the 802.xx wireless protocols discussed here.