question: How do planes have Wi-Fi while in flight?
comment: They either connect to cellular networks or via satellite if the flight is out over water. Other than that, it's just like wifi at home. You have a router and a wifi access point that everyone connects to.
passages: Section::::Digital systems.:Efficiency of flight.
   In the past few years, many US commercial airlines have begun testing and deploying in-flight connectivity for their passengers, such as Alaska Airlines, American, Delta, and United. Industry expectations were that by the end of 2011, thousands of planes flying in the US will offer some form of in-flight broadband to passengers. Airlines around the world are also beginning to test in-flight-broadband offerings as well.
  
  Section::::In-flight connectivity.:Satellite and internal telephony.
   IFE producers have begun to introduce Intranet type systems. Virgin Atlantic's and Virgin Australia's Entertainment Systems allow for passengers to chat amongst one another, compete against each other in the provided games, talk to the flight attendants and request, and pay for in advance, food or drinks, and have full access to the internet and email. Other full service airlines such as China Airlines have launched IFEs with similar functionalities onboard their Boeing 777 and Airbus A350 aircraft.
  
  Section::::In-flight connectivity.:Wi-Fi.
   Section::::Innovations.:Wi-Fi.
   Section::::Varieties of in-flight entertainment.:Islamic prayers and directions to Mecca.
  
  In several airlines from the Muslim world the AVOD systems provide Qibla directions to allow Muslims to pray toward Mecca (e.g. Emirates, Iran Air, Etihad, Malaysia Airlines, Qatar Airways, Royal Jordanian and Saudia); Malaysia Airlines has built-in Qur'an e-books and Garuda Indonesia has a unique Qur'an channel. Emirates also has built-in complete audio Qur'an.
  
  Section::::In-flight connectivity.
   Several airlines are testing in-cabin wi-fi systems. In-flight internet service is provided either through a satellite network or an air-to-ground network. In the Airbus A380 aircraft, data communication via satellite system allows passengers to connect to live Internet from the individual IFE units or their laptops via the in-flight Wi-Fi access.
   Section::::Digital systems.:Redundancy.
   Wiring adds a considerable amount of weight to an aircraft; therefore, researchers are exploring implementing fly-by-wireless solutions. Fly-by-wireless systems are very similar to fly-by-wire systems, however, instead of using a wired protocol for the physical layer a wireless protocol is employed.
   More modern systems allow passengers to call fellow passengers located in another seat by simply keying in the recipient's seat number.
  
  Section::::In-flight connectivity.:Data communication.
   Since the shuttering of Connexion by Boeing, several new providers have emerged to deliver in-flight broadband to airlines—notably Row 44, OnAir and AeroMobile (who offer satellite-based solutions), and Aircell (which offers air-to-ground connectivity via a cellular signal).
   On 29 May 2013, KLM and Air France launched a pilot to test inflight Wi-Fi. Both airlines have equipped one Boeing 777-300ER of each of their fleets with Wi-Fi. Using the inflight Wi-Fi, passengers can stay online using their Wi-Fi enabled smartphones, laptops, or tablets. Wireless service would commence once the flight has reached 20,000 feet.
  
  Section::::Services.:Le Salon.
   Sixteen major U.S. airlines now offer Wi-Fi connectivity service on their aircraft. The majority of these airlines use the service provided by Gogo Wi-Fi service. The service allows for Wi-Fi enabled devices to connect to the Internet. Delta currently has the most Wi-Fi equipped fleet with 500 aircraft that now offer in-flight Wi-Fi.
  
  In 2019 some airlines removed seatback screens, saving money by streaming video to passenger personal mobile devices.
  
  Section::::In-flight connectivity.:Mobile phone.
   In late 2009, Lufthansa announced that starting mid-2010 they will re-launch their 'FlyNet' service with Panasonic Avionics' satellite-based broadband technology offering passengers in-flight Internet and cellphone connections. Lufthansa will make use of their existing onboard hardware that had been installed in 2003 by Connexion by Boeing, the now defunct provider of the airline's previous onboard connectivity system.
  
  Section::::Operations.
   Gogo's ATG network is a cellular (meaning that there is a hand-off when the aircraft moves between service areas) radio network that has more than 200 towers in the continental U.S., Alaska and Canada. The ground stations consist of original Airfone air-ground phone relay stations and newer locations, using the 850 MHz ATG band. Unlike terrestrial cell sites, ATG ground stations project a directional signal up into the air where airplanes are, rather than downward, where terrestrial users are. However the short wavelength used allows segmentation and other "cellular" technologies in the same way that terrestrial cellphone technology works. The aircraft communicates with the ground stations through an antenna installed on the underbelly of the fuselage. Equipment in the aircraft's avionics bay converts between proprietary Gogo protocols and standard Wi-Fi, which is distributed into the passenger cabin through multiple interior wireless access point nodes.
   Personal AVOD screens are provided on all Boeing 777-200ER, Boeing 747-400 and Boeing 787s. Streaming with iPads and smartphones by an El Al app is provided on the Boeing 737-900ER and some Boeing 737-800, where there are no personal AVOD screens.
  
  Section::::Accidents and incidents.
   On October 20, 2009, Apple unveiled an updated AirPort Extreme base station with antenna improvements.
  
  On June 21, 2011, Apple unveiled an updated AirPort Extreme base station, referred to as "AirPort Extreme 802.11n (5th Generation)".
  
  Section::::AirPort routers.:AirPort Express.
   While no further CRJ100 or CRJ200 jet liners have been constructed since 2006, over the years since then, various technologies and innovations have been retrofitted onto examples of the type, which have largely remained in commercial service. Some of the operators of the larger versions, such as the CRJ700, have undertaken work to install Wi-Fi capabilities on board the type; however, to date, no airlines operating the CRJ200/100 had chosen to implement an onboard Wi-Fi compatibility.
   In most cases, it is possible to reach flight service stations either by radio in flight, or by telephone on the ground. Recently, some countries, such as Canada and the United States, have been consolidating flight services into large regional centres, replacing former local flight service stations with remote communications outlets (RCOs) connected to the centres.
  
  Section::::Flight services in different countries.
  
  Section::::Flight services in different countries.:Flight services in the United States.
   On October 20, 2009, Apple unveiled the updated AirPort Extreme and Time Capsule products with antenna improvements (the 5.8 GHz model).
   AeroMobile and OnAir allow the use of personal electronics devices aboard flights. The services are most readily available in Europe and are licensed to specific airlines.
  
  BULLET::::- Qantas
  
  Since 26 August 2014 Qantas permits mobile phones (and other portable electronic devices weighing less than 1 kg) to be switched on during the entire flight, if the devices are in flight mode while on board the aircraft. Jetstar (owned by Qantas) adopted the same arrangements on 30 August 2014.
  
  BULLET::::- Ryanair
   As being strictly imposed by the LTFRB, they have on-board video and music which play unpirated movies and music and TV receiver to provide passengers with the TV program they want.
   Routers that incorporate a digital subscriber line modem or a cable modem and a Wi-Fi access point, often set up in homes and other buildings, provide Internet access and internetworking to all devices connected to them, wirelessly or via cable.
   The fourth generation Time Capsule, released in June 2011, increased the range of WiFi signals. The internal Wi-Fi card was changed from a Marvell Wi-Fi chip to a better-performing Broadcom BCM4331 chip. Apple again increased the storage space in each model as the hard drive sizes were increased to 2 and 3 TB. The 2 TB and 3 TB models were kept at the $299 and $499 price points.
   Section::::Further developments.
  
  Section::::Further developments.:Fly-by-optics.
   The AirPort Express functions as a wireless access point when connected to an Ethernet network. It can be used as an Ethernet-to-wireless bridge under certain wireless configurations.
  
  It can be used to extend the range of a network, or as a printer and audio server.
  
  In 2012, the AirPort Express took on a new shape, similar to that of the second and third generation Apple TV. The new product also features two 10/100 Mbit/s Ethernet LAN ports.
  
  Section::::AirPort routers.:AirPort Time Capsule.
  