109-590: QinetiQ ( / k ɪ ˈ n ɛ t ɪ k / as in kinetic ) is a multinational defence technology company headquartered in Farnborough, Hampshire . It operates primarily in the defence, security and critical national infrastructure markets and run testing and evaluation capabilities for air, land, sea and target systems. As a private entity, QinetiQ was created in April 2001; prior to this its assets had been part of Defence Evaluation and Research Agency (DERA),
218-450: 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
327-427: A the acceleration of the object and the distance traveled by the accelerated object in time t , we find with v = a t {\displaystyle v=at} for the velocity v of the object The work done in accelerating a particle with mass m during the infinitesimal time interval dt is given by the dot product of force F and the infinitesimal displacement d x where we have assumed
436-530: A Special Security Arrangement which allows it to work independently and separately on some of the most sensitive United States defense programs despite its foreign ownership. It has also spun off some of its technologies into new companies, such as Omni-ID Ltd . It is currently a constituent of the FTSE 250 Index . "QinetiQ" is an invented name. " Qi " is supposed to reflect the company's energy, "net" its networking ability, and "iq" its intellectual resources. The name
545-468: A UK-based provider of software for high end secure messaging, primarily for military, government and security customers worldwide. In March 2007, QinetiQ spun off a new company, Omni-ID Ltd ; this entity specialises in the commercial opportunities for passive UHF radio-frequency identification (RFID) tags. Prior to the spin off, a research team at QinetiQ had been active since the 1990s to develop new and more effective RFID technologies. On 9 February 2007,
654-647: 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,
763-410: A body's mass, inertia, and total energy. In fluid dynamics , the kinetic energy per unit volume at each point in an incompressible fluid flow field is called the dynamic pressure at that point. Dividing by V, the unit of volume: where q {\displaystyle q} is the dynamic pressure, and ρ is the density of the incompressible fluid. The speed, and thus the kinetic energy of
872-447: 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
981-460: 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,
1090-461: A competitive edge over most private-sector rivals. Initially, QinetiQ was entirely owned by the British government; it was planned for a stock market flotation of the firm to be conducted sometime during 2002. However, this flotation was postponed; according to aerospace industry periodical Flight International , a lack of investor confidence was the principal reason for the delay. In late 2002,
1199-407: 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
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#17328021376441308-550: 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
1417-641: 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
1526-511: A large advertising campaign. The issue was partially resolved by allowing some brokerage firms to place orders in the IPO as part of a combined order, allowing the firm to purchase as though an institutional investor but on behalf of clients. While this did not result in a public campaign or retail investor discounts, it did allow many investors to purchase shares. Upon its floating on 10 February 2006, QinetiQ had an IPO of 200p per share, resulting in
1635-589: A market value of £1.3bn. On 13 February 2006, shares closed at 219.5p, valuing it at over £1.4bn. Speculation that a consortium including QinetiQ was about to win a £10bn MoD training contract helped push their share price back above 190p in early November 2006. It was announced on 17 January 2007 that the QinetiQ-led Metrix consortium was the preferred bidder for package one of the MoD's Defence Training Rationalisation programme, worth approx £16bn. In 2007,
1744-461: A now-defunct British government organisation. While a large portion of DERA's assets, sites, and employees were transferred to QinetiQ, other elements were incorporated into Defence Science and Technology Laboratory (DSTL), which remains in government ownership. Some former DERA locations have thus become key sites for QinetiQ. These include Farnborough, Hampshire; MoD Boscombe Down , Wiltshire; and Malvern, Worcestershire . In February 2006, QinetiQ
1853-426: 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
1962-410: 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
2071-402: A single object is frame-dependent (relative): it can take any non-negative value, by choosing a suitable inertial frame of reference . For example, a bullet passing an observer has kinetic energy in the reference frame of this observer. The same bullet is stationary to an observer moving with the same velocity as the bullet, and so has zero kinetic energy. By contrast, the total kinetic energy of
2180-523: A stock exchange float would take place. In September 2004, QinetiQ acquired the US defence companies Westar Corporation and Foster-Miller , maker of the Talon robot. Also in 2004, it acquired HVR Consulting Services a leading UK-based engineering consultancy. In early August 2005, the company announced it would acquire Apogen Technologies, Inc. , pending regulatory approval; according to QinetiQ's website,
2289-468: A system depends on the inertial frame of reference : it is the sum of the total kinetic energy in a center of momentum frame and the kinetic energy the total mass would have if it were concentrated in the center of mass . This may be simply shown: let V {\displaystyle \textstyle \mathbf {V} } be the relative velocity of the center of mass frame i in the frame k . Since Wi-Fi Wi-Fi ( / ˈ w aɪ f aɪ / )
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#17328021376442398-449: A system of objects cannot be reduced to zero by a suitable choice of the inertial reference frame, unless all the objects have the same velocity. In any other case, the total kinetic energy has a non-zero minimum, as no inertial reference frame can be chosen in which all the objects are stationary. This minimum kinetic energy contributes to the system's invariant mass , which is independent of the reference frame. The total kinetic energy of
2507-635: 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
2616-615: 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
2725-577: 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
2834-456: Is a good approximation of kinetic energy only when v is much less than the speed of light . The adjective kinetic has its roots in the Greek word κίνησις kinesis , meaning "motion". The dichotomy between kinetic energy and potential energy can be traced back to Aristotle 's concepts of actuality and potentiality . The principle of classical mechanics that E ∝ mv is conserved
2943-569: 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
3052-554: 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
3161-421: Is dissipated in various forms of energy, such as heat, sound and binding energy (breaking bound structures). Flywheels have been developed as a method of energy storage . This illustrates that kinetic energy is also stored in rotational motion. Several mathematical descriptions of kinetic energy exist that describe it in the appropriate physical situation. For objects and processes in common human experience,
3270-432: 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
3379-446: Is equal to where: The kinetic energy of any entity depends on the reference frame in which it is measured. However, the total energy of an isolated system, i.e. one in which energy can neither enter nor leave, does not change over time in the reference frame in which it is measured. Thus, the chemical energy converted to kinetic energy by a rocket engine is divided differently between the rocket ship and its exhaust stream depending upon
Qinetiq - Misplaced Pages Continue
3488-419: Is equal to 1/2 the product of the mass and the square of the speed. In formula form: where m {\displaystyle m} is the mass and v {\displaystyle v} is the speed (magnitude of the velocity) of the body. In SI units, mass is measured in kilograms , speed in metres per second , and the resulting kinetic energy is in joules . For example, one would calculate
3597-418: Is simply the sum of the kinetic energies of its moving parts, and is thus given by: where: (In this equation the moment of inertia must be taken about an axis through the center of mass and the rotation measured by ω must be around that axis; more general equations exist for systems where the object is subject to wobble due to its eccentric shape). A system of bodies may have internal kinetic energy due to
3706-593: 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
3815-550: Is the movement energy of an object. Kinetic energy can be transferred between objects and transformed into other kinds of energy. Kinetic energy may be best understood by examples that demonstrate how it is transformed to and from other forms of energy. For example, a cyclist uses chemical energy provided by food to accelerate a bicycle to a chosen speed. On a level surface, this speed can be maintained without further work, except to overcome air resistance and friction . The chemical energy has been converted into kinetic energy,
3924-417: 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
4033-644: The Carlyle Group , an American private equity firm, publicly declared its intention to purchase a large stake in QinetiQ. In February 2003, the Carlyle Group completed the acquisition of a 33.8% share for £42 million. Prior to QinetiQ's flotation years later, ownership of the firm was divided between the MoD (56%), Carlyle Group (31%) and staff (13%). The Carlyle Group was expected to remain invested in QinetiQ for between three and five years, after which
4142-551: 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
4251-505: 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
4360-522: The Ministry of Defence (MoD) would retain a 'special share' in the company, while safeguards would be in place to prevent conflicts of interest. By April 2002, while QinetiQ had taken steps to operate on a commercial basis and saw third parties as its key growth area, 80% of its annual sales was reportedly being derived from the UK MoD. It was observed that QinetiQ's close relationship with the MoD gave it
4469-537: The National Audit Office conducted an inquiry into the privatisation to determine whether UK taxpayers received good value for money. The inquiry looked at the following issues: In November 2007, the NAO reported that taxpayers could have gained "tens of millions" more and was critical of the incentive scheme given to QinetiQ managers, the 10 most senior of whom gained £107.5m on an investment of £540,000 in
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4578-560: The Times Top 100 Graduate Employers list. During 2005, QinetiQ was accused by union officials of its employees exhibiting higher than average levels of stress-related depression , a finding that was strongly denied by the company. On March 25, 2021, a worker was seriously injured at a QinetiQ-run Ministry of Defence facility in Pendine, Carmarthen. The company's services and products include: Kinetic energy In physics ,
4687-853: 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
4796-504: The kinetic energy of an object is the form of energy that it possesses due to its motion . In classical mechanics , the kinetic energy of a non-rotating object of mass m traveling at a speed v is 1 2 m v 2 {\textstyle {\frac {1}{2}}mv^{2}} . The kinetic energy of an object is equal to the work , force ( F ) times displacement ( s ), needed to achieve its stated velocity . Having gained this energy during its acceleration ,
4905-455: 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
5014-608: 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
5123-408: 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
5232-427: 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
5341-573: 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,
5450-498: The Carlyle Group sold its remaining 10.3% stake in the group at 205p per share, resulting in a £290 million return on its original investment. During September 2008, the MoD sold its remaining 18.9% holding in QinetiQ at 206p per share, raising £254 million. The British government retained its 'special share', giving it control over any potential takeover. In February 2020, QinetiQ acquired military training specialist Newman & Spurr Consultancy Ltd for £14 million. In November 2022, it
5559-615: 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
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#17328021376445668-594: 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
5777-690: The Long Term partnering Agreement (LTPA) with the UK Ministry of Defence (MoD) to provide test and evaluation services and manage military ranges. It is a major stakeholder in the UK Defence Technology Centre , which places military research contracts on behalf of the MoD. QinetiQ has a 25-year Maritime Strategic Facilities Agreement (MSCA) with the MoD to provide strategic maritime facilities and capabilities, including hydromechanic facilities at Haslar, biomedical facilities on
5886-629: The Paramarine software suite of ship and submarine design tools. On 12 January 2006, an announcement was made in Parliament by John Reid , Secretary of State for Defence, regarding the pending floatation of QinetiQ. Reid stated that the Carlyle Group 'will continue to retain a significant stake in the company', and that the government would continue to hold a ' golden share ' to protect the UK's security and defence interests. On 10 February 2006, QinetiQ
5995-570: 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
6104-416: The UK's South Coast, and submarine structures, survivability and shock testing facilities at Rosyth. The QinetiQ Group comprises QinetiQ EMEA (Europe, Middle East and Australasia) and QinetiQ North America. QinetiQ North America, which was set up after the takeover of Foster-Miller , is a wholly owned subsidiary of QinetiQ, but remains independent and separated from the QinetiQ group by a proxy agreement with
6213-563: The US Transportation Security Administration for railway stations and airports. During August 2008, QinetiQ's Zephyr , a solar powered unmanned aerial vehicle (UAV), performed a non-stop flight spanning 14 days; this was a world record for the longest duration unmanned flight. Over the following years, Qinetic performed further record-breaking flights of the UAV. During summer 2018, an improved model of
6322-466: The US to comply with US laws that prevent sensitive technology coming under the control of a foreign venture that takes over a US company. The major UK sites are at Farnborough , Hampshire (the historical Royal Aircraft Establishment ) and Malvern, Worcestershire (the historical RSRE / RRE / TRE ). QinetiQ is one of the ten largest UK employers of science and engineering graduates, recruiting around 150 per year. Between 2002 and 2006, it has appeared in
6431-543: 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
6540-481: The Zephyr conducted an even-longer flight, lasting nearly 26 days. The Zephyr UAV has been offered as a commercial product, the programme having been acquired by multinational aerospace company Airbus Group . QinetiQ have been involved in the further development of the Zephyr, such as the provision of LIDAR payload for the type. QinetiQ has a 25-year T3E (Test, Trials, Training and Evaluation) agreement formerly called
6649-605: 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
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#17328021376446758-481: 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
6867-569: 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
6976-480: The chosen reference frame. This is called the Oberth effect . But the total energy of the system, including kinetic energy, fuel chemical energy, heat, etc., is conserved over time, regardless of the choice of reference frame. Different observers moving with different reference frames would however disagree on the value of this conserved energy. The kinetic energy of such systems depends on the choice of reference frame:
7085-767: The company announced the launch of a strategic collaboration with information security firm Nexor to pool their cyber security portfolios. During 2016, QinetiQ released a whitepaper on the topic, which identified employee behaviour as a major contributing factor in the majority of security breaches. QinetiQ has partnered with mobile phone network provider Vodafone to support end-to-end internet security services. QinetiQ provides technology-based products and services to numerous government and commercial customers. More than 2,000 of QinetiQ subsidiary Foster-Miller's Talon robots have been deployed to Iraq and Afghanistan , most used to remotely locate and disable roadside bombs. QinetiQ's SPO stand-off threat detection system has been sold to
7194-404: The company's shares. The return of 19,990% was described as "excessive" by the NAO. The role of QinetiQ's management in negotiating terms with the Carlyle Group while the private equity company was bidding for the business was also criticised by the NAO. Carlyle bought a third of the business for £42m, which grew in value to £372m in less than four years. However, the Ministry of Defence defended
7303-519: 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
7412-458: The energy of motion, but the process is not completely efficient and produces heat within the cyclist. The kinetic energy in the moving cyclist and the bicycle can be converted to other forms. For example, the cyclist could encounter a hill just high enough to coast up, so that the bicycle comes to a complete halt at the top. The kinetic energy has now largely been converted to gravitational potential energy that can be released by freewheeling down
7521-414: 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
7630-432: The formula 1 / 2 mv given by classical mechanics is suitable. However, if the speed of the object is comparable to the speed of light, relativistic effects become significant and the relativistic formula is used. If the object is on the atomic or sub-atomic scale , quantum mechanical effects are significant, and a quantum mechanical model must be employed. Treatments of kinetic energy depend upon
7739-399: The game of billiards , the player imposes kinetic energy on the cue ball by striking it with the cue stick. If the cue ball collides with another ball, it slows down dramatically, and the ball it hit accelerates as the kinetic energy is passed on to it. Collisions in billiards are effectively elastic collisions , in which kinetic energy is preserved. In inelastic collisions , kinetic energy
7848-439: The hill than without the generator because some of the energy has been diverted into electrical energy. Another possibility would be for the cyclist to apply the brakes, in which case the kinetic energy would be dissipated through friction as heat . Like any physical quantity that is a function of velocity, the kinetic energy of an object depends on the relationship between the object and the observer's frame of reference . Thus,
7957-515: The implications of the experiment and published an explanation. The terms kinetic energy and work in their present scientific meanings date back to the mid-19th century. Early understandings of these ideas can be attributed to Thomas Young , who in his 1802 lecture to the Royal Society, was the first to use the term energy to refer to kinetic energy in its modern sense, instead of vis viva . Gaspard-Gustave Coriolis published in 1829
8066-428: The kinetic energy of an 80 kg mass (about 180 lbs) traveling at 18 metres per second (about 40 mph, or 65 km/h) as When a person throws a ball, the person does work on it to give it speed as it leaves the hand. The moving ball can then hit something and push it, doing work on what it hits. The kinetic energy of a moving object is equal to the work required to bring it from rest to that speed, or
8175-445: The kinetic energy of an object is not invariant . Spacecraft use chemical energy to launch and gain considerable kinetic energy to reach orbital velocity . In an entirely circular orbit, this kinetic energy remains constant because there is almost no friction in near-earth space. However, it becomes apparent at re-entry when some of the kinetic energy is converted to heat. If the orbit is elliptical or hyperbolic , then throughout
8284-465: The mass maintains this kinetic energy unless its speed changes. The same amount of work is done by the object when decelerating from its current speed to a state of rest . The SI unit of kinetic energy is the joule , while the English unit of kinetic energy is the foot-pound . In relativistic mechanics , 1 2 m v 2 {\textstyle {\frac {1}{2}}mv^{2}}
8393-453: The molecular or atomic level, which may be regarded as kinetic energy, due to molecular translation, rotation, and vibration, electron translation and spin, and nuclear spin. These all contribute to the body's mass, as provided by the special theory of relativity. When discussing movements of a macroscopic body, the kinetic energy referred to is usually that of the macroscopic movement only. However, all internal energies of all types contribute to
8502-542: 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,
8611-452: 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
8720-411: The orbit kinetic and potential energy are exchanged; kinetic energy is greatest and potential energy lowest at closest approach to the earth or other massive body, while potential energy is greatest and kinetic energy the lowest at maximum distance. Disregarding loss or gain however, the sum of the kinetic and potential energy remains constant. Kinetic energy can be passed from one object to another. In
8829-412: The other side of the hill. Since the bicycle lost some of its energy to friction, it never regains all of its speed without additional pedaling. The energy is not destroyed; it has only been converted to another form by friction. Alternatively, the cyclist could connect a dynamo to one of the wheels and generate some electrical energy on the descent. The bicycle would be traveling slower at the bottom of
8938-739: The paper titled Du Calcul de l'Effet des Machines outlining the mathematics of kinetic energy. William Thomson , later Lord Kelvin, is given the credit for coining the term "kinetic energy" c. 1849–1851. William Rankine , who had introduced the term "potential energy" in 1853, and the phrase "actual energy" to complement it, later cites William Thomson and Peter Tait as substituting the word "kinetic" for "actual". Energy occurs in many forms, including chemical energy , thermal energy , electromagnetic radiation , gravitational energy , electric energy , elastic energy , nuclear energy , and rest energy . These can be categorized in two main classes: potential energy and kinetic energy. Kinetic energy
9047-566: 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
9156-511: The purchase came at a cost of $ 288.0m (£162.7m). In September 2005, the company acquired a 90% share of Verhaert Design and Development NV (VDD), a Belgian space systems integrator. In October that year, it acquired Broadreach Networks Limited, a supplier of Wi-Fi internet equipment to the European rail industry, and in February 2006, it bought Graphics Research Corporation Ltd, developer of
9265-551: 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
9374-504: 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
9483-409: The reference frame that gives the minimum value of that energy is the center of momentum frame, i.e. the reference frame in which the total momentum of the system is zero. This minimum kinetic energy contributes to the invariant mass of the system as a whole. The work W done by a force F on an object over a distance s parallel to F equals Using Newton's Second Law with m the mass and
9592-408: The relationship p = m v and the validity of Newton's Second Law . (However, also see the special relativistic derivation below .) Applying the product rule we see that: Therefore, (assuming constant mass so that dm = 0), we have, Since this is a total differential (that is, it only depends on the final state, not how the particle got there), we can integrate it and call
9701-575: The relative motion of the bodies in the system. For example, in the Solar System the planets and planetoids are orbiting the Sun. In a tank of gas, the molecules are moving in all directions. The kinetic energy of the system is the sum of the kinetic energies of the bodies it contains. A macroscopic body that is stationary (i.e. a reference frame has been chosen to correspond to the body's center of momentum ) may have various kinds of internal energy at
9810-434: The relative velocity of objects compared to the fixed speed of light . Speeds experienced directly by humans are non-relativisitic ; higher speeds require the theory of relativity . In classical mechanics , the kinetic energy of a point object (an object so small that its mass can be assumed to exist at one point), or a non-rotating rigid body depends on the mass of the body as well as its speed . The kinetic energy
9919-523: The result kinetic energy: This equation states that the kinetic energy ( E k ) is equal to the integral of the dot product of the momentum ( p ) of a body and the infinitesimal change of the velocity ( v ) of the body. It is assumed that the body starts with no kinetic energy when it is at rest (motionless). If a rigid body Q is rotating about any line through the center of mass then it has rotational kinetic energy ( E r {\displaystyle E_{\text{r}}\,} ) which
10028-559: The sale to be delayed, but was over-ruled by the Treasury, which had convinced the Ministry of Defence to go ahead. Controversy also arose around the fact that retail investors were excluded from the initial public offering (IPO) due to QinetiQ's complexity and that institutional investors would require less complicated marketing and financing. This led to contrasts with the 'Sid' campaign for British Gas plc in 1986, where retail investors were encouraged to buy shares, with discounts and
10137-481: The sale: In January 2007, the company bought Analex , a US corporation that provides high technology professional services, principally to the US government and its agencies. It was originally incorporated in 1964 under the name Biorad and evolved into Hadron , a US government systems consulting firm. In February 2007, the acquisition of ITS Corporation, a provider of IT services to the US government and its agencies,
10246-400: 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,
10355-515: 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
10464-445: 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
10573-762: 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
10682-434: The work the object can do while being brought to rest: net force × displacement = kinetic energy , i.e., Since the kinetic energy increases with the square of the speed, an object doubling its speed has four times as much kinetic energy. For example, a car traveling twice as fast as another requires four times as much distance to stop, assuming a constant braking force. As a consequence of this quadrupling, it takes four times
10791-435: The work to double the speed. The kinetic energy of an object is related to its momentum by the equation: where: For the translational kinetic energy, that is the kinetic energy associated with rectilinear motion , of a rigid body with constant mass m {\displaystyle m} , whose center of mass is moving in a straight line with speed v {\displaystyle v} , as seen above
10900-639: 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
11009-481: Was adopted in early 2001 as a marker of Defence Evaluation and Research Agency (DERA) privatisation; the rebranding reportedly cost £400,000. In early 2001, defence minister Lewis Moonie announced the creation of QinetiQ via the privatisation of the Defence Evaluation and Research Agency (DERA). At the time, Moonie stated that the entity would remain a British business, being based in the UK, and that
11118-468: Was announced QinetiQ had completed the acquisition of the McLean -headquartered provider of cybersecurity and data analytics software to US government agencies, Avantus Federal for $ 590 million USD. During mid-2013, reports emerged that Chinese hackers had allegedly compromised sensitive military research being performed by QinetiQ. It was claimed that, between 2007 and 2010, QinetiQ's North American business
11227-412: Was announced. The disposal of Aerospace Filtration Systems (formerly part of Westar) was announced at the same time. In June of that year, QinetiQ announced that Apogen Technologies Inc., its US subsidiary, had completed the acquisition of 3H Technology LLC, a specialist IT company with US government and commercial clients. In October, the company completed the acquisition of Boldon James Holdings Limited ,
11336-441: Was first developed by Gottfried Leibniz and Johann Bernoulli , who described kinetic energy as the living force or vis viva . Willem 's Gravesande of the Netherlands provided experimental evidence of this relationship in 1722. By dropping weights from different heights into a block of clay, Gravesande determined that their penetration depth was proportional to the square of their impact speed. Émilie du Châtelet recognized
11445-577: Was floated on the London Stock Exchange . The privatisation process was subject to an inquiry by the UK's National Audit Office , which was critical of the generous incentive scheme available to the company's management. QinetiQ has completed numerous acquisitions of defence- and technology-related companies, primarily those that are based in the United States , and is a trusted supplier to the US government. QinetiQ USA operates under
11554-422: Was floated on the London Stock Exchange . The valuation of the company, and of how much taxpayers would benefit from QinetiQ's privatisation, was a subject of considerable debate and controversy. The company had been valued at between £1.1bn and £1.3bn, with the MoD holding estimated to be worth £616m – £728m, the Carlyle Group's holding £341m – £403m, and staff/management's holding worth £143m – £169m. Controversy
11663-412: Was generated by the very large returns generated for both the Carlyle Group and senior managers at the company; reportedly Sir John Chisholm is speculated to have benefitted by over £20 million alone. Lord Moonie , who handled the initial sale, stated in 2006 that the government's 31 per cent stake should not have been sold when equity markets were languishing in 2002. Moonie said that he had argued for
11772-429: 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
11881-554: Was the subject of a cyber-attack . At the time of the incidents, the company said it disclosed all of its breaches to the responsible government agencies and these were resolved to their satisfaction. The Pentagon has stated that it still entrusts QinetiQ with sensitive defence technology. The issue of cyber security affected other organisations; a Pentagon report stated that various US government agencies had been victims of cyberattacks. QinetiQ provides auditing and consultancy services on cyber security to third party businesses. In 2011,
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