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IEEE 802.11g-2003
IEEE 802.11g-2003 or 802.11g is an amendment to the IEEE 802.11 specification that operates in the 2.4 GHz microwave band. The standard has extended link rate to up to 54 Mbit/s using the same 20 MHz Bandwidth (computing), bandwidth as 802.11b channels, 802.11b uses to achieve 11 Mbit/s. This specification, under the marketing name of Wi‑Fi, has been implemented all over the world. The 802.11g protocol is now Clause 19 of the published IEEE 802.11-2007#802.11-2007, IEEE 802.11-2007 standard, and Clause 19 of the published IEEE 802.11#802.11-2012, IEEE 802.11-2012 standard. 802.11 is a set of IEEE standards that govern wireless networking transmission methods. They are commonly used today in their 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac and 802.11ax versions to provide wireless connectivity in the home, office and some commercial establishments. 802.11g is fully backward compatible with 802.11b, but coexistence of the two methods creates a significant performance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Mbit/s
In telecommunications, data transfer rate is the average number of bits (bitrate), characters or symbols (baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are multiples of bits per second (bit/s) and bytes per second (B/s). For example, the data rates of modern residential high-speed Internet connections are commonly expressed in megabits per second (Mbit/s). Standards for unit symbols and prefixes Unit symbol The International System of Quantities, ISQ symbols for the bit and byte are ''bit'' and ''B'', respectively. In the context of data-rate units, one byte consists of 8 bits, and is synonymous with the unit Octet (computing), octet. The abbreviation bps is often used to mean bit/s, so that when a ''1 Mbps'' connection is advertised, it usually means that the maximum achievable bandwidth is 1 Mbit/s (one million bits per second), which is 0.125 MB/s (megabyte per second), or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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OFDM
In telecommunications, orthogonal frequency-division multiplexing (OFDM) is a type of digital transmission used in digital modulation for encoding digital (binary) data on multiple carrier frequencies. OFDM has developed into a popular scheme for wideband digital communication, used in applications such as digital television and audio broadcasting, DSL internet access, wireless networks, power line networks, and 4G/ 5G mobile communications. OFDM is a frequency-division multiplexing (FDM) scheme that was introduced by Robert W. Chang of Bell Labs in 1966. In OFDM, the incoming bitstream representing the data to be sent is divided into multiple streams. Multiple closely spaced orthogonal subcarrier signals with overlapping spectra are transmitted, with each carrier modulated with bits from the incoming stream so multiple bits are being transmitted in parallel. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Super G (wireless Networking)
Super G is a proprietary method to increase the throughput of an IEEE 802.11g (Wi-Fi) wireless LAN. Atheros uses frame-bursting, compression, and channel bonding technology to improve performance. The throughput transmission speed limit when using Super G is claimed to be up to 40 Mbit/s-60 Mbit/s at a 108 Mbit/s signaling rate, which is achieved through the bonding of two 54 Mbit/s 802.11g channels. Vendors Other vendors have marketed Super G products as 108G Technology, 108 Mbit/s 802.11g, Xpress technology and Xtreme G. Manufacturers that have licensed Super G technology from Atheros include Airlink 101, Clipsal, D-Link, Intelbras, LevelOne, Netgear, Nortel Networks, Planex, SMC, Sony, TRENDnet, SparkLAN, Toshiba and ZyXEL. In general, Super G products from different vendors are all interoperable in Super G mode. Interference Non-standard channel bonding extensions to 802.11g such as Super G, have been criticized for creating interference ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Wi-Fi
Wi-Fi () is a family of wireless network protocols based on the IEEE 802.11 family of standards, which are commonly used for Wireless LAN, local area networking of devices and Internet access, allowing nearby digital devices to exchange data by radio waves. These are the most widely used computer networks, used globally in small office/home office, home and small office networks to link devices and to provide Internet access with wireless routers and wireless access points in public places such as coffee shops, restaurants, hotels, libraries, and airports. ''Wi-Fi'' is a trademark of the Wi-Fi Alliance, which restricts the use of the term "''Wi-Fi Certified''" to products that successfully complete Interoperability Solutions for European Public Administrations, interoperability certification testing. Non-compliant hardware is simply referred to as WLAN, and it may or may not work with "''Wi-Fi Certified''" devices. the Wi-Fi Alliance consisted of more than 800 companies from ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Spectral Efficiency Comparison Table
Spectral efficiency, spectrum efficiency or bandwidth efficiency refers to the information rate that can be transmitted over a given bandwidth in a specific communication system. It is a measure of how efficiently a limited frequency spectrum is utilized by the physical layer protocol, and sometimes by the medium access control (the channel access protocol). Guowang Miao, Jens Zander, Ki Won Sung, and Ben Slimane, Fundamentals of Mobile Data Networks, Cambridge University Press, , 2016. Link spectral efficiency The link spectral efficiency of a digital communication system is measured in '' bit/ s/ Hz'', or, less frequently but unambiguously, in ''(bit/s)/Hz''. It is the net bit rate (useful information rate excluding error-correcting codes) or maximum throughput divided by the bandwidth in hertz of a communication channel or a data link. Alternatively, the spectral efficiency may be measured in ''bit/symbol'', which is equivalent to ''bits per channel use'' (''bpcu''), imp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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OFDM System Comparison Table
In telecommunications, orthogonal frequency-division multiplexing (OFDM) is a type of digital transmission used in digital modulation for encoding digital (binary) data on multiple carrier frequencies. OFDM has developed into a popular scheme for wideband digital communication, used in applications such as digital television and audio broadcasting, DSL internet access, wireless networks, power line networks, and 4G/ 5G mobile communications. OFDM is a frequency-division multiplexing (FDM) scheme that was introduced by Robert W. Chang of Bell Labs in 1966. In OFDM, the incoming bitstream representing the data to be sent is divided into multiple streams. Multiple closely spaced orthogonal subcarrier signals with overlapping spectra are transmitted, with each carrier modulated with bits from the incoming stream so multiple bits are being transmitted in parallel. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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List Of WLAN Channels
Wireless LAN (WLAN) channels are frequently accessed using IEEE 802.11 protocols. The 802.11 standard provides several radio frequency bands for use in Wi-Fi communications, each divided into a multitude of channels numbered at 5 MHz spacing (except in the 45/60 GHz band, where they are 0.54/1.08/2.16 GHz apart) between the centre frequency of the channel. The standards allow for channels to be bonded together into wider channels for faster throughput. 860/900 MHz (802.11ah) 802.11ah operates in sub-gigahertz unlicensed bands. Each world region supports different sub-bands, and the channels number depends on the starting frequency on the sub-band it belongs to. Therefore there is no global channels numbering plan, and the channels numbers are incompatible between world regions (and even between sub-bands of a same world region). The following sub-bands are defined in the 802.11ah specifications: 2.4 GHz (802.11b/g/n/ax/be) 14 channels are designated in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Clear Channel Assessment Attack
A clear channel assessment attack or Queensland attack is a physical layer DoS attack against Wi-Fi networks. The attack focuses the need of a wireless network to receive the "clear channel assessment"; which is a function within CSMA/CA to determine whether the wireless medium is ready and able to receive data, so that the transmitter may start sending it. The attack makes it appear that the airwaves are busy, which basically puts the entire system on hold. The attack works only on 802.11b, and is not effective on the OFDM-based protocols 802.11g and 802.11a. However, some hybrid 802.11b/g access points will hinder the 802.11g network when the 802.11b network is attacked. Discovery The attack was originally discovered by researchers at Queensland University of Technology's Information Security Research Center, thus it is where the name ''Queensland attack'' comes from. In practice The signal telling the system the airwaves are busy is of course sent through the attacker's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Side Lobe
In antenna engineering, sidelobes are the lobes (local maxima) of the far field radiation pattern of an antenna or other radiation source, that are not the ''main lobe''. The radiation pattern of most antennas shows a pattern of "''lobes''" at various angles, directions where the radiated signal strength reaches a maximum, separated by "''nulls''", angles at which the radiated signal strength falls to zero. This can be viewed as the diffraction pattern of the antenna. In a directional antenna in which the objective is to emit the radio waves in one direction, the lobe in that direction is designed to have a larger field strength than the others; this is the "''main lobe''". The other lobes are called "''sidelobes''", and usually represent unwanted radiation in undesired directions. The sidelobe directly behind the main lobe is called the back lobe. The longer the antenna relative to the radio wavelength, the more lobes its radiation pattern has. In transmitting antennas, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Bluetooth
Bluetooth is a short-range wireless technology standard that is used for exchanging data between fixed and mobile devices over short distances and building personal area networks (PANs). In the most widely used mode, transmission power is limited to 2.5 milliwatts, giving it a very short range of up to . It employs Ultra high frequency, UHF radio waves in the ISM bands, from 2.402GHz to 2.48GHz. It is mainly used as an alternative to wired connections to exchange files between nearby portable devices and connect cell phones and music players with wireless headphones, wireless speakers, HIFI systems, car audio and wireless transmission between TVs and soundbars. Bluetooth is managed by the Bluetooth Special Interest Group (SIG), which has more than 35,000 member companies in the areas of telecommunication, computing, networking, and consumer electronics. The Institute of Electrical and Electronics Engineers, IEEE standardized Bluetooth as IEEE 802.15.1 but no longer maintains ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Broadcom BCM2050KMLG (49724268213)
Broadcom Inc. is an American multinational corporation, multinational designer, developer, manufacturer, and global supplier of a wide range of semiconductor and infrastructure software products. Broadcom's product offerings serve the data center, networking, software, broadband, wireless, storage, and industrial markets. As of 2024, some 58 percent of Broadcom's revenue came from its semiconductor-based products and 42 percent from its infrastructure software products and services. Tan Hock Eng is the company's president and chief executive officer, CEO. The company is headquartered in Palo Alto, California. Avago Technologies Limited was changing its name to ''Broadcom'' to acquire Broadcom Corporation in January 2016. Avago's ticker symbol AVGO now represents the merged entity. The Broadcom Corporation ticker symbol BRCM was retired. Initially the merged entity was known as ''Broadcom Limited'', before assuming the current name in November 2017. In October 2019, the Europe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |