92-541: (Redirected from WOL ) Wol , WoL or WOL may refer to: Computing [ edit ] Wake-on-LAN , (/wɒl/) an Ethernet standard that allows computers to be powered on by a network message An unofficial initialism for Web Ontology Language .wol , file extension for the WOLF eBook file format World Online , a defunct European internet service provider Computer games [ edit ] War of Legends , (/wɒl/)
184-450: A captive portal webpage for access. Organizations, enthusiasts, authorities and businesses , such as airports, hotels, and restaurants, often provide free or paid-use hotspots to attract customers, to provide services to promote business in selected areas. Routers often incorporate a digital subscriber line modem or a cable modem and a Wi-Fi access point, are frequently set up in homes and other buildings, to provide Internet access for
276-457: A frame that is most often sent as a broadcast and that contains anywhere within its payload 6 bytes of all 255 (FF FF FF FF FF FF in hexadecimal ), followed by sixteen repetitions of the target computer's 48-bit MAC address, for a total of 102 bytes. Since the magic packet is only scanned for the string above, and not actually parsed by a full protocol stack, it could be sent as payload of any network- and transport-layer protocol, although it
368-464: A subnet . Wake-on-LAN can, however, operate across any network in practice, given appropriate configuration and hardware, including remote wake-up across the Internet. In order for Wake-on-LAN to work, parts of the network interface need to stay on. This consumes a small amount of standby power . To further reduce power consumption, the link speed is usually reduced to the lowest possible speed (e.g.
460-399: A Gigabit Ethernet NIC maintains only a 10 Mbit/s link). Disabling Wake-on-LAN, when not needed, can slightly reduce power consumption on computers that are switched off but still plugged into a power socket. The power drain becomes a consideration on battery-powered devices such as laptops as this can deplete the battery even when the device is completely shut down. The magic packet is
552-710: A LAN to cause a WoL packet to be sent to a host when that machine accesses one of the host's shared resources. Wake-on-LAN support may be changed using a subfunction of the ethtool command, for example: In the early days of Wake-on-LAN the situation was relatively simple: a machine was connected to power but switched off, and it was arranged that a special packet be sent to switch the machine on. Since then many options have been added and standards agreed upon. A machine can be in seven power states from S0 (fully on) through S5 (powered down but plugged in) and disconnected from power (G3, Mechanical Off), with names such as "sleep", "standby", and "hibernate". In some reduced-power modes
644-647: A Wi-Fi network. Wi-Fi uses a large number of patents held by many different organizations. Australia, the United States and the Netherlands simultaneously claim the invention of Wi-Fi, and a consensus has not been reached globally. In 2009, the Australian CSIRO was awarded $ 200 million after a patent settlement with 14 technology companies, with a further $ 220 million awarded in 2012 after legal proceedings with 23 companies. In 2016,
736-447: A city-wide campaign to convert old phone booths into digital kiosks in 2014. The project, titled LinkNYC , has created a network of kiosks that serve as public Wi-Fi hotspots, high-definition screens and landlines . Installation of the screens began in late 2015. The city government plans to implement more than seven thousand kiosks over time, eventually making LinkNYC the largest and fastest public, government-operated Wi-Fi network in
828-460: A common Wi-Fi version. The versions differ between the radio wavebands they operate on, the radio bandwidth they occupy, the maximum data rates they can support and other details. Some versions permit the use of multiple antennas, which permits greater speeds as well as reduced interference. Historically, the equipment listed the versions of Wi-Fi supported using the name of the IEEE standards. In 2018,
920-407: A computer and an interface controller is called a station . Stations are identified by one or more MAC addresses . Wi-Fi nodes often operate in infrastructure mode in which all communications go through a base station. Ad hoc mode refers to devices communicating directly with each other, without communicating with an access point. A service set is the set of all the devices associated with
1012-429: A computer with an attacker's boot image, bypassing any security of the installed operating system and granting access to unprotected, local disks over the network. The use of Wake-on-LAN technology on enterprise networks can sometimes conflict with network access control solutions such as 802.1X MAC-based authentication, which may prevent magic packet delivery if a machine's WoL hardware has not been designed to maintain
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#17327652237021104-467: A fantasy real-time strategy game published by Jagex Games Studio Warhammer Online , abbreviation used internally by Games Workshop staff StarCraft II: Wings of Liberty Westwood Online, multi-player game mode by Westwood Studios, superseded by XWIS Transport [ edit ] Shellharbour Airport , Wollongong, Australia IATA code Wood Lane tube station , London Underground station code Other uses [ edit ] Owl (Winnie
1196-550: A founding member of the Wi-Fi Alliance, the term Wi-Fi was chosen from a list of ten names that Interbrand proposed. Interbrand also created the Wi-Fi logo . The yin-yang Wi-Fi logo indicates the certification of a product for interoperability . The name is often written as WiFi , Wifi , or wifi , but these are not approved by the Wi-Fi Alliance. The name Wi-Fi is not short-form for 'Wireless Fidelity', although
1288-641: A greater degree by common building materials than the 2.4 GHz bands and usually give a shorter range. As 802.11 specifications evolved to support higher throughput, the protocols have become much more efficient in their bandwidth use. Additionally, they have gained the ability to aggregate channels together to gain still more throughput where the bandwidth for additional channels is available. 802.11n allows for double radio spectrum bandwidth (40 MHz) per channel compared to 802.11a or 802.11g (20 MHz). 802.11n can be set to limit itself to 20 MHz bandwidth to prevent interference in dense communities. In
1380-520: A live authentication session while in a sleep state. Some PCs include technology built into the chipset to improve security for Wake-on-LAN. For example, Intel AMT (a component of Intel vPro technology). AMT uses TLS encryption to secure an out-of-band communication tunnel to an AMT-based PC for remote management commands such as Wake-on-LAN. AMT secures the communication tunnel with Advanced Encryption Standard (AES) 128-bit encryption and RSA keys with modulus lengths of 2,048 bits. Because
1472-760: A local client often become known as "The Wake On LAN Server" to users. Additionally, software that administers WoL capabilities from the host OS side may be carelessly referred to as a client on occasion; Machines running WoL generally tend to be end-user desktops, and as such, are clients in IT parlance. Software to send WoL magic packets is available for all modern platforms, including Windows, Macintosh and Linux, plus many smartphones . Examples include: Wake On LAN GUI, LAN Helper, Magic Packet Utility, NetWaker for Windows, Nirsoft WakeMeOnLAN, WakeOnLANx, EMCO WOL, Aquila Tech Wake on LAN, ManageEngine WOL utility, FusionFenix and SolarWinds WOL Tool. There are also web sites that allow
1564-476: A magic packet to be sent online without charge. Example source code for a developer to add Wake-on-LAN to a program is readily available in many computer languages . The following example is in Python : If the sender is on the same subnet or local area network as the computer to be awakened there are generally no issues. When sending over the Internet, and in particular where a network address translation (NAT)
1656-551: A networking layer below typical IP usage. In the NAT router, ARP binding requires a dedicated IP and the MAC address of the destination computer. There are some security implications associated with ARP binding (see ARP spoofing ); however, as long as none of the computers connected to the LAN are compromised, an attacker must use a computer that is connected directly to the target LAN (plugged into
1748-426: A particular Wi-Fi network. Devices in a service set need not be on the same wavebands or channels. A service set can be local, independent, extended, mesh, or a combination. Each service set has an associated identifier, a 32-byte service set identifier (SSID), which identifies the network. The SSID is configured within the devices that are part of the network. A basic service set (BSS) is a group of stations that share
1840-697: A power supply. On desktops, the feature is controlled via the System Settings Energy Saver panel. Marking the Wake for network access checkbox enables Wake-on-LAN. It can also be configured through the terminal using the pmset womp (wake on magic packet) command. Apple's Apple Remote Desktop client management system can be used to send Wake-on-LAN packets, but there are also freeware and shareware macOS applications available. A mechanism called Bonjour Sleep Proxy , provided by Apple AirPort access points and Apple TVs, allows other machines on
1932-410: A single carrier, whereas 802.11a, Wi-Fi 4, 5 and 6 use orthogonal frequency-division multiplexing . Channels are used half duplex and can be time-shared by multiple networks. Any packet sent by one computer is locally received by stations tuned to that channel, even if that information is intended for just one destination. Stations typically ignore information not addressed to them. The use of
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#17327652237022024-660: A specific data pattern detected by the Ethernet-controller on the receiving end”. AMD implemented the WoL mechanism in their AMD PCnet II -Family of Ethernet controllers before. The term “Magic Packet” is a AMD trademark. Wake-on-LAN saw wide adoption starting in October 1996, when IBM formed the Advanced Manageability Alliance (AMA) with Intel . In April 1997, this alliance adopted
2116-408: A standard in 1995. The standard saw quick adoption thereafter through IBM , Intel and others. Equivalent terms include wake on WAN , remote wake-up , power on by LAN , power up by LAN , resume by LAN , resume on LAN and wake up on LAN . If the computer being awakened is communicating via Wi-Fi , a supplementary standard called Wake on Wireless LAN (WoWLAN) must be employed. The message
2208-635: A team of scientists began working on wireless LAN technology. A prototype test bed for a wireless local area network (WLAN) was developed in 1992 by a team of researchers from the Radiophysics Division of the CSIRO (Commonwealth Scientific and Industrial Research Organisation) in Australia, led by John O'Sullivan . A patent for Wi Fi was lodged by the CSIRO in 1992 The first version of
2300-615: A wider channel for higher throughput. Countries apply their own regulations to the allowable channels, allowed users and maximum power levels within these frequency ranges. 802.11b/g/n can use the 2.4 GHz band, operating in the United States under FCC Part 15 rules and regulations. In this frequency band, equipment may occasionally suffer interference from microwave ovens, cordless telephones , USB 3.0 hubs, Bluetooth and other devices. Spectrum assignments and operational limitations are not consistent worldwide: Australia and Europe allow for an additional two channels (12, 13) beyond
2392-569: Is a trademark of the Wi-Fi Alliance , which restricts the use of the term " Wi-Fi Certified " to products that successfully complete interoperability certification testing. Non-compliant hardware is simply referred to as WLAN , and it may or may not work with " Wi-Fi Certified " devices. As of 2017, the Wi-Fi Alliance consisted of more than 800 companies from around the world. As of 2019, over 3.05 billion Wi-Fi-enabled devices are shipped globally each year. Wi-Fi uses multiple parts of
2484-554: Is about 20 m (66 ft) indoors, while some access points claim up to a 150 m (490 ft) range outdoors. Hotspot coverage can be as small as a single room with walls that block radio waves or as large as many square kilometers using many overlapping access points with roaming permitted between them. Over time, the speed and spectral efficiency of Wi-Fi have increased. As of 2019, some versions of Wi-Fi, running on suitable hardware at close range, can achieve speeds of 9.6 Gbit/s ( gigabit per second). A 1985 ruling by
2576-447: Is also required. The Intel adapter allows "Wake on Directed Packet", "Wake on Magic Packet", "Wake on Magic Packet from power off state", and "Wake on Link". Wake on Directed Packet is particularly useful as the machine will automatically come out of standby or hibernation when it is referenced, without the user or application needing to explicitly send a magic packet. Unfortunately in many networks waking on directed packet (any packet with
2668-460: Is causing the power-up – the device being the soft power switch, the NIC (via Wake-on-LAN), the cover being opened, a temperature change, etc. The three-pin WoL interface on the motherboard consists of: pin 1, +5V DC (red); pin 2, ground (black); pin 3, wake signal (green or yellow). By supplying the pin-3 wake signal with +5V DC the computer will be triggered to power up provided WoL
2760-496: Is designed to be simple and to be quickly processed by the circuitry present on the network interface controller using minimal power. Because Wake-on-LAN operates below the IP protocol layer, IP addresses and DNS names are meaningless and so the MAC address is required. A principal limitation of standard broadcast Wake-on-LAN is that broadcast packets are generally not routed. This prevents the technique being used in larger networks or over
2852-437: Is different from Wikidata All article disambiguation pages All disambiguation pages Wake-on-LAN Wake-on-LAN ( WoL or WOL ) is an Ethernet or Token Ring computer networking standard that allows a computer to be turned on or awakened from sleep mode by a network message. It is based upon AMD 's Magic Packet Technology , which was co-developed by AMD and Hewlett-Packard, following its proposal as
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2944-432: Is divided into a multitude of channels . In the standards, channels are numbered at 5 MHz spacing within a band (except in the 60 GHz band, where they are 2.16 GHz apart), and the number refers to the centre frequency of the channel. Although channels are numbered at 5 MHz spacing, transmitters generally occupy at least 20 MHz, and standards allow for neighbouring channels to be bonded together to form
3036-494: Is enabled in the BIOS/UEFI configuration. ‹The template Manual is being considered for merging .› Software that sends a WoL magic packet is referred to in different circles as client or server , which can be a source of confusion. While WoL hardware or firmware is arguably performing the role of a server , Web-based interfaces that act as a gateway through which users can issue WoL packets without downloading
3128-437: Is implemented on the motherboard of a computer and in the network interface controller . It is consequently not dependent on the operating system running on the computer. In order to get Wake-on-LAN to work, enabling this feature on the network interface card or on-board silicon is sometimes required. Details of how to do this depend upon the operating system and the device driver. Wake-on-LAN usually needs to be enabled in
3220-456: Is involved (as typically in most homes), special settings are often necessary. Further, the WoL protocol operates on a deeper level in the multi-layer networking architecture. To ensure the magic packet gets from source to destination while the destination is sleeping, the ARP binding must typically be set in a NAT router. This allows the router to forward the magic packet to the sleeping computer at
3312-527: Is relayed through the PCI bus. The power supply must meet ATX 2.01 specifications. Laptops powered by the Intel Centrino processor technology or newer (with explicit BIOS/UEFI support) allow waking up the machine using Wake on Wireless LAN (WoWLAN). In most modern PCs, ACPI is notified of the waking up and takes control of the power-up. In ACPI, OSPM must record the wake source or the device that
3404-641: Is submitted for certification. The lack of Wi-Fi certification does not necessarily imply that a device is incompatible with other Wi-Fi devices. The Wi-Fi Alliance may or may not sanction derivative terms, such as Super Wi-Fi , coined by the US Federal Communications Commission (FCC) to describe proposed networking in the UHF TV band in the US. Equipment frequently supports multiple versions of Wi-Fi. To communicate, devices must use
3496-437: Is typically sent as a UDP datagram to port 0 (reserved port number), 7 ( Echo Protocol ) or 9 ( Discard Protocol ), or directly over Ethernet using EtherType 0x0842. A connection-oriented transport-layer protocol like TCP is less suited for this task as it requires establishing an active connection before sending user data. A standard magic packet has the following basic limitations: The Wake-on-LAN implementation
3588-601: Is unsupported in Windows 8 and above, and Windows Server 2012 and above. This is because of a change in the OS behavior which causes network adapters to be explicitly not armed for WoL when shutdown to these states occurs. WOL from a non-hybrid hibernation state (S4) (i.e. when a user explicitly requests hibernation) or a sleep state (S3) is supported. However, some hardware will enable WoL from states that are unsupported by Windows. Modern Mac hardware supports WoL functionality when
3680-417: Is used in applications such as motion detection and gesture recognition . Wi-Fi stations communicate by sending each other data packets , blocks of data individually sent and delivered over radio on various channels. As with all radio, this is done by the modulation and demodulation of carrier waves . Different versions of Wi-Fi use different techniques, 802.11b uses direct-sequence spread spectrum on
3772-523: Is usually sent to the target computer by a program executed on a device connected to the same local area network (LAN). It is also possible to initiate the message from another network by using subnet directed broadcasts or a WoL gateway service. The WoL and WoWLAN standards are often supplemented by vendors to provide protocol-transparent on-demand services, for example in the Apple Bonjour wake-on-demand ( Sleep Proxy ) feature. The basis for
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3864-551: The Eduroam international authentication infrastructure. In the early 2000s, many cities around the world announced plans to construct citywide Wi-Fi networks. There are many successful examples; in 2004, Mysore (Mysuru) became India's first Wi-Fi-enabled city. A company called WiFiyNet has set up hotspots in Mysore, covering the whole city and a few nearby villages. In 2005, St. Cloud, Florida and Sunnyvale, California , became
3956-499: The IEEE 802 protocol family and is designed to work seamlessly with its wired sibling, Ethernet . Compatible devices can network through wireless access points with each other as well as with wired devices and the Internet. Different versions of Wi-Fi are specified by various IEEE 802.11 protocol standards, with different radio technologies determining radio bands, maximum ranges, and speeds that may be achieved. Wi-Fi most commonly uses
4048-538: The Wake-on-LAN -industry standard mechanism today, was created around 1994 by AMD in cooperation with Hewlett-Packard , who co-developed AMD's Magic Packet Technology and brought forth their following proposal for it in November 1995 in an AMD whitepaper. It enabled a remote network device to be woken up through the underlying “power management circuitry”, by sending it a standard Ethernet frame, which “contains
4140-853: The Wi-Fi Alliance introduced simplified Wi-Fi generational numbering to indicate equipment that supports Wi-Fi 4 ( 802.11n ), Wi-Fi 5 ( 802.11ac ) and Wi-Fi 6 ( 802.11ax ). These generations have a high degree of backward compatibility with previous versions. The alliance has stated that the generational level 4, 5, or 6 can be indicated in the user interface when connected, along with the signal strength. The most important standards affecting Wi‑Fi are: 802.11a, 802.11b, 802.11g, 802.11n ( Wi-Fi 4 ), 802.11h, 802.11i, 802.11-2007, 802.11–2012, 802.11ac ( Wi-Fi 5 ), 802.11ad, 802.11af, 802.11-2016, 802.11ah, 802.11ai, 802.11aj, 802.11aq , 802.11ax ( Wi-Fi 6 ), 802.11ay . Wi-Fi technology may be used to provide local network and Internet access to devices that are within Wi-Fi range of one or more routers that are connected to
4232-455: The 11 permitted in the United States for the 2.4 GHz band, while Japan has three more (12–14). 802.11a/h/j/n/ac/ax can use the 5 GHz U-NII band , which, for much of the world, offers at least 23 non-overlapping 20 MHz channels. This is in contrast to the 2.4 GHz frequency band where the channels are only 5 MHz wide. In general, lower frequencies have longer range but have less capacity. The 5 GHz bands are absorbed to
4324-608: The 2.4 gigahertz (120 mm) UHF and 5 gigahertz (60 mm) SHF radio bands, with the 6 gigahertz SHF band used in newer generations of the standard; these bands are subdivided into multiple channels. Channels can be shared between networks, but, within range, only one transmitter can transmit on a channel at a time. Wi-Fi's radio bands work best for line-of-sight use. Many common obstructions, such as walls, pillars, home appliances, etc., may greatly reduce range, but this also helps minimize interference between different networks in crowded environments. The range of an access point
4416-408: The 5 GHz band, 20 MHz, 40 MHz, 80 MHz, and 160 MHz channels are permitted with some restrictions, giving much faster connections. Wi-Fi is part of the IEEE 802 protocol family. The data is organized into 802.11 frames that are very similar to Ethernet frames at the data link layer, but with extra address fields. MAC addresses are used as network addresses for routing over
4508-427: The 802.11 protocol was released in 1997, and provided up to 2 Mbit/s link speeds. This was updated in 1999 with 802.11b to permit 11 Mbit/s link speeds. In 1999, the Wi-Fi Alliance formed as a trade association to hold the Wi-Fi trademark under which most IEEE 802.11 products are sold. The major commercial breakthrough came with Apple Inc. adopting Wi-Fi for their iBook series of laptops in 1999. It
4600-573: The CSIRO's WLAN prototype test bed was chosen as Australia's contribution to the exhibition A History of the World in 100 Objects held in the National Museum of Australia . The name Wi-Fi , commercially used at least as early as August 1999, was coined by the brand-consulting firm Interbrand. The Wi-Fi Alliance had hired Interbrand to create a name that was "a little catchier than 'IEEE 802.11b Direct Sequence'." According to Phil Belanger,
4692-433: The Internet. Subnet-directed broadcasts (SDBs) may be used to overcome this limitation. SDB may require changes to the intermediate router configuration. SDBs are treated like unicast network packets until processed by the final (local) router. This router then broadcasts the packet using a layer-2 broadcast. This technique allows a broadcast to be initiated on a remote network but requires all intervening routers to forward
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#17327652237024784-615: The Internet. The coverage of one or more interconnected access points can extend from an area as small as a few rooms to as large as many square kilometres. Coverage in the larger area may require a group of access points with overlapping coverage. For example, public outdoor Wi-Fi technology has been used successfully in wireless mesh networks in London. An international example is Fon . Wi-Fi provides services in private homes, businesses, as well as in public spaces. Wi-Fi hotspots may be set up either free of charge or commercially, often using
4876-580: The LAN via cable, or by breaking through the Wi‑Fi connection security) to gain access to the LAN. Most home routers are able to send magic packets to a LAN; for example, routers with the DD-WRT , Tomato or PfSense firmware have a built-in Wake-on-LAN client. OpenWrt supports both Linux implementations for WoL. Most WoL hardware functionally is typically blocked by default and needs to be enabled in using
4968-545: The LAN. Wi-Fi's MAC and physical layer (PHY) specifications are defined by IEEE 802.11 for modulating and receiving one or more carrier waves to transmit the data in the infrared, and 2.4, 3.6 , 5, 6, or 60 GHz frequency bands. They are created and maintained by the IEEE LAN/MAN Standards Committee ( IEEE 802 ). The base version of the standard was released in 1997 and has had many subsequent amendments. The standard and amendments provide
5060-422: The NIC a hexadecimal password of 6 bytes. Clients append this password to the magic packet. The NIC wakes the system only if the MAC address and password are correct. This security measure significantly decreases the risk of successful brute force attacks , by increasing the search space by 48 bits (6 bytes), up to 2 combinations if the MAC address is entirely unknown. However, any network eavesdropping will expose
5152-680: The Pooh) , character in the Winnie the Pooh stories, who spells his name "Wol" Wide outside lane , in bicycle transportation engineering Within Our Lifetime , a pro-Palestinian activist organization Wol, the main character of Mobius Final Fantasy WOL (AM) , a radio station in Washington, D.C. See also [ edit ] Word of Life (disambiguation) Topics referred to by
5244-485: The Power Management section of a PC motherboard's BIOS/UEFI setup utility, although on some systems, such as Apple computers, it is enabled by default. On older systems the BIOS/UEFI setting may be referred to as WoL; on newer systems supporting PCI version 2.2, it may be referred to as PME (Power Management Events, which include WoL). It may also be necessary to configure the computer to reserve standby power for
5336-736: The SDB. When preparing a network to forward SDB packets, care must be taken to filter packets so that only desired (e.g. WoL) SDB packets are permitted – otherwise the network may become a participant in DDoS attacks such as the Smurf attack . Wake-on-LAN can be a difficult technology to implement because it requires appropriate BIOS/ UEFI , network interface hardware and, sometimes, operating system and router support to function reliably. In some cases, hardware may wake from one low-power state but not from others. This means that due to hardware issues
5428-570: The U.S. Federal Communications Commission released parts of the ISM bands for unlicensed use for communications. These frequency bands include the same 2.4 GHz bands used by equipment such as microwave ovens , and are thus subject to interference. In 1991 in Nieuwegein , the NCR Corporation and AT&T invented the precursor to 802.11, intended for use in cashier systems, under
5520-424: The Wake-on-LAN function as reliable as possible. For a machine procured to work in this way, Wake-on-LAN functionality is an important part of the purchase procedure. Some machines do not support Wake-on-LAN after they have been disconnected from power (e.g., when power is restored after a power failure). Use of an uninterruptible power supply (UPS) will give protection against a short period without power, although
5612-505: The Wake-on-LAN technology. Ethernet connections, including home and work networks, wireless data networks, and the Internet itself, are based on frames sent between computers. WoL is implemented using a specially designed frame called a magic packet , which is commonly sent to all computers in a network, among them the computer to be awakened. The magic packet contains the MAC address of
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#17327652237025704-543: The Wi-Fi Alliance did use the advertising slogan "The Standard for Wireless Fidelity" for a short time after the brand name was created, and the Wi-Fi Alliance was also called the "Wireless Fidelity Alliance Inc." in some publications. IEEE is a separate, but related, organization and their website has stated "WiFi is a short name for Wireless Fidelity". The name Wi-Fi was partly chosen because it sounds similar to Hi-Fi , which consumers take to mean high fidelity or high quality . Interbrand hoped consumers would find
5796-419: The ability to wake from an ACPI S5 power off state), installation of the full driver suite from the network device manufacturer may be necessary, rather than the bare driver provided by Microsoft or the computer manufacturer. In most cases correct BIOS/UEFI configuration is also required for WoL to function. The ability to wake from a hybrid shutdown state (S4) (aka Fast Startup) or a soft powered-off state (S5)
5888-419: The adapter's MAC address or IP address) or on link is likely to cause wakeup immediately after going to a low-power state. Details for any particular motherboard and network adapter are to be found in the relevant manuals; there is no general method. Knowledge of signals on the network may also be needed to prevent spurious wakening. For a machine which is normally unattended, precautions need to be taken to make
5980-605: The basis for wireless network products using the Wi-Fi brand. While each amendment is officially revoked when incorporated in the latest version of the standard, the corporate world tends to market to the revisions because they concisely denote capabilities of their products. As a result, in the market place, each revision tends to become its own standard. In addition to 802.11, the IEEE 802 protocol family has specific provisions for Wi-Fi. These are required because Ethernet's cable-based media are not usually shared, whereas with wireless all transmissions are received by all stations within
6072-639: The battery will discharge during a prolonged power-cut. Wi-Fi Wi-Fi ( / ˈ w aɪ f aɪ / ) is a family of wireless network protocols based on the IEEE 802.11 family of standards, which are commonly used for 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 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, hotels, libraries, and airports. Wi-Fi
6164-481: The capability. Some laptops that have a cellular modem card can also act as mobile Internet Wi-Fi access points. Many traditional university campuses in the developed world provide at least partial Wi-Fi coverage. Carnegie Mellon University built the first campus-wide wireless Internet network, called Wireless Andrew , at its Pittsburgh campus in 1993 before Wi-Fi branding existed. Many universities collaborate in providing Wi-Fi access to students and staff through
6256-569: The channel to be idle at the same time and thus begin transmission simultaneously. A collision happens when a station receives signals from multiple stations on a channel at the same time. This corrupts the transmitted data and can require stations to re-transmit. The lost data and re-transmission reduces throughput, in some cases severely. The 802.11 standard provides several distinct radio frequency ranges for use in Wi-Fi communications: 900 MHz , 2.4 GHz, 3.6 GHz, 4.9 GHz, 5 GHz, 6 GHz and 60 GHz bands . Each range
6348-402: The cleartext password. Abuse of the Wake-on-LAN feature only allows computers to be switched on; it does not in itself bypass password and other forms of security, and is unable to power off the machine once on. However, many client computers attempt booting from a PXE server when powered up by WoL. Therefore, a combination of DHCP and PXE servers on the network can sometimes be used to start
6440-572: The computer is in a sleep state, but it is not possible to wake up a Mac computer from a powered-off state. Mac OS X Snow Leopard and later support WoL, which is called Wake on Demand. On laptops, the feature is controlled via the macOS System Settings Battery panel, in the Options pop-up window. The Wake for network access item can be set to "Always", "Only on Power Adapter", or "Never"; "Always" enables Wake-on-LAN even when on battery power, but "Only on Power Adapter" enables it only when connected to
6532-454: The computer may be wakeable from its soft off state (S5) but doesn't wake from sleep or hibernation or vice versa. Starting with Windows Vista, the operating system logs all wake sources in the System event log. The Event Viewer and the powercfg.exe /lastwake command can retrieve them. Magic packets are sent via the data link or OSI-2 layer , which can be used or abused by anyone on
6624-463: The computer's power supply or motherboard to awaken. This has the same effect as pressing the power button. The magic packet is broadcast on the data link layer to all attached devices on a given network, using the network broadcast address ; the IP address (which relates to the internet layer ) is not used. Because Wake-on-LAN is built upon broadcast messaging, it can generally only be used within
6716-519: The database. Signal fluctuations can cause errors, which can be reduced with noise-filtering techniques. For low precision, integrating Wi-Fi data with geographical and time information has been proposed. The Wi-Fi RTT capability introduced in IEEE 802.11mc allows for positioning based on round trip time measurement, an improvement over the RSSI method. The IEEE 802.11az standard promises further improvements in geolocation accuracy. Wi-Fi sensing
6808-453: The destination computer. This is an identifying number, built into each network interface controller (NIC), that enables the NIC to be uniquely recognized and addressed on a network. In computers capable of Wake-on-LAN, the NIC(s) listen to incoming packets, even when the rest of the system is powered down. If a magic packet arrives and is addressed to the device's MAC address, the NIC signals
6900-809: The encrypted communication is out-of-band, the PC's hardware and firmware receive the magic packet before network traffic reaches the software stack for the operating system (OS). Since the encrypted communication occurs below the OS level, it is less vulnerable to attacks by viruses, worms, and other threats that typically target the OS level. IT shops using Wake-on-LAN through the Intel AMT implementation can wake an AMT PC over network environments that require TLS-based security, such as IEEE 802.1X , Cisco Self Defending Network (SDN), and Microsoft Network Access Protection (NAP) environments. The Intel implementation also works for wireless networks. Wake-on-LAN support
6992-414: The first cities in the United States to offer citywide free Wi-Fi (from MetroFi ). Minneapolis has generated $ 1.2 million in profit annually for its provider . In May 2010, the then London mayor Boris Johnson pledged to have London-wide Wi-Fi by 2012. Several boroughs including Westminster and Islington already had extensive outdoor Wi-Fi coverage at that point. New York City announced
7084-542: The name WaveLAN . NCR's Vic Hayes , who held the chair of IEEE 802.11 for ten years, along with Bell Labs engineer Bruce Tuch, approached the Institute of Electrical and Electronics Engineers (IEEE) to create a standard and were involved in designing the initial 802.11b and 802.11a specifications within the IEEE. They have both been subsequently inducted into the Wi-Fi NOW Hall of Fame. In 1989 in Australia,
7176-452: The name catchy, and that they would assume this wireless protocol has high fidelity because of its name. Other technologies intended for fixed points, including Motorola Canopy , are usually called fixed wireless . Alternative wireless technologies include Zigbee , Z-Wave , Bluetooth and mobile phone standards . To connect to a Wi-Fi LAN, a computer must be equipped with a wireless network interface controller . The combination of
7268-467: The network card when the system is shut down. With older motherboards, if the network interface is a plug-in card rather than being integrated into the motherboard there may be a header onboard connected to the network card via a special three-pin cable the card. Systems supporting the PCI 2.2 standard and with a PCI 2.2 compliant network adapter card do not usually require a cable as the required standby power
7360-566: The project, which was to be completed in 2015. Wi-Fi positioning systems use known positions of Wi-Fi hotspots to identify a device's location. It is used when GPS isn't suitable due to issues like signal interference or slow satellite acquisition. This includes assisted GPS , urban hotspot databases, and indoor positioning systems. Wi-Fi positioning relies on measuring signal strength ( RSSI ) and fingerprinting. Parameters like SSID and MAC address are crucial for identifying access points. The accuracy depends on nearby access points in
7452-551: The range that employ that radio channel. While Ethernet has essentially negligible error rates, wireless communication media are subject to significant interference. Therefore, the accurate transmission is not guaranteed so delivery is, therefore, a best-effort delivery mechanism. Because of this, for Wi-Fi, the Logical Link Control (LLC) specified by IEEE 802.2 employs Wi-Fi's media access control (MAC) protocols to manage retries without relying on higher levels of
7544-504: The receiver uses the destination address to determine whether the transmission is relevant to the station or should be ignored. A scheme known as carrier-sense multiple access with collision avoidance (CSMA/CA) governs the way stations share channels. With CSMA/CA stations attempt to avoid collisions by beginning transmission only after the channel is sensed to be idle, but then transmit their packet data in its entirety. CSMA/CA cannot completely prevent collisions, as two stations may sense
7636-534: The same LAN, unless the L2 LAN equipment is capable of and configured for filtering such traffic to match site-wide security requirements. Firewalls may be used to prevent clients among the public WAN from accessing the broadcast addresses of inside LAN segments, or routers may be configured to ignore subnet-directed broadcasts. Certain NICs support a security feature called "SecureOn". It allows users to store within
7728-400: The same channel also means that the data bandwidth is shared, so for example, available throughput to each device is halved when two stations are actively transmitting. As with other IEEE 802 LANs, stations come programmed with a globally unique 48-bit MAC address. The MAC addresses are used to specify both the destination and the source of each data packet. On the reception of a transmission,
7820-451: The same term [REDACTED] This disambiguation page lists articles associated with the title Wol . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Wol&oldid=1228320033 " Categories : Disambiguation pages Broadcast call sign disambiguation pages Hidden categories: Short description
7912-515: The same wireless channel, SSID, and other settings that have wirelessly connected, usually to the same access point. Each BSS is identified by a MAC address called the BSSID . The IEEE does not test equipment for compliance with their standards. The Wi-Fi Alliance was formed in 1999 to establish and enforce standards for interoperability and backward compatibility , and to promote wireless local-area-network technology. The Wi-Fi Alliance enforces
8004-445: The structure. Similarly, battery-powered routers may include a mobile broadband modem and a Wi-Fi access point. When subscribed to a cellular data carrier, they allow nearby Wi-Fi stations to access the Internet. Many smartphones have a built-in mobile hotspot capability of this sort, though carriers often disable the feature, or charge a separate fee to enable it. Standalone devices such as MiFi - and WiBro -branded devices provide
8096-473: The system BIOS/UEFI. Further configuration from the OS is required in some cases, for example via the Device Manager network card properties on Windows operating systems. Newer versions of Microsoft Windows integrate WoL functionality into the Device Manager. This is available in the Power Management tab of each network device's driver properties. For full support of a device's WoL capabilities (such as
8188-462: The system state is stored in RAM and the machine can wake up very quickly; in others the state is saved to disk and the motherboard powered down, taking at least several seconds to wake up. The machine can be awakened from a reduced-power state by a variety of signals. The machine's BIOS/UEFI must be set to allow Wake-on-LAN. To allow wakeup from powered-down state S5, wakeup on PME (Power Management Event)
8280-762: The use of the Wi-Fi brand to technologies based on the IEEE 802.11 standards from the IEEE. Manufacturers with membership in the Wi-Fi Alliance, whose products pass the certification process, gain the right to mark those products with the Wi-Fi logo. Specifically, the certification process requires conformance to the IEEE 802.11 radio standards, the WPA and WPA2 security standards, and the EAP authentication standard. Certification may optionally include tests of IEEE 802.11 draft standards, interaction with cellular-phone technology in converged devices, and features relating to security set-up, multimedia, and power-saving. Not every Wi-Fi device
8372-639: The world. The UK has planned a similar project across major cities of the country, with the project's first implementation in the London Borough of Camden . Officials in South Korea's capital Seoul were moving to provide free Internet access at more than 10,000 locations around the city, including outdoor public spaces, major streets, and densely populated residential areas. Seoul was planning to grant leases to KT, LG Telecom, and SK Telecom. The companies were supposed to invest $ 44 million in
8464-429: Was the first mass consumer product to offer Wi-Fi network connectivity, which was then branded by Apple as AirPort . This was in collaboration with the same group that helped create the standard: Vic Hayes , Bruce Tuch, Cees Links , Rich McGinn, and others from Lucent . In the year 2000, Radiata, a group of Australian scientists connected to the CSIRO, were the first to use the 802.11a standard on chips connected to
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