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Wi-Fi Direct (formerly Wi-Fi Peer-to-Peer) is a Wi-Fi standard for peer-to-peer wireless connections [1] that allows two devices to establish a direct Wi-Fi connection without an intermediary wireless access point, router, or Internet connection. Wi-Fi Direct is single-hop communication, rather than multi-hop communication like wireless ad hoc networks.
Wi-Fi becomes a way of communicating wirelessly, much like Bluetooth. It is useful for everything from internet browsing to file transfer, [2] [3] and to communicate with one or more devices simultaneously at typical Wi-Fi speeds. [4] One advantage of Wi-Fi Direct is the ability to connect devices even if they are from different manufacturers. Only one of the Wi-Fi devices needs to be compliant with Wi-Fi Direct to establish a peer-to-peer connection that transfers data directly between them with greatly reduced setup. [5]
Wi-Fi Direct negotiates the link with a Wi-Fi Protected Setup system that assigns each device a limited wireless access point. The "pairing" of Wi-Fi Direct devices can be set up to require the proximity of a near field communication, a Bluetooth signal, or a button press on one or all the devices.
Conventional Wi-Fi networks are typically based on the presence of controller devices known as wireless access points. These devices normally combine three primary functions:
A typical Wi-Fi home network includes laptops, tablets and phones, devices like modern printers, music devices, and televisions. Most Wi-Fi networks are set up in infrastructure mode, where the access point acts as a central hub to which Wi-Fi capable devices are connected. All communication between devices goes through the access point.
In contrast, Wi-Fi Direct devices are able to communicate with each other without requiring a dedicated wireless access point. The Wi-Fi Direct devices negotiate when they first connect to determine which device shall act as an access point.[ citation needed ]
With the increase in the number and type of devices attaching to Wi-Fi systems, the basic model of a simple router with smart computers became increasingly strained. At the same time, the increasing sophistication of the hot spots presented setup problems for the users. To address these problems, there have been numerous attempts to simplify certain aspects of the setup task.
A common example is the Wi-Fi Protected Setup system included in most access points manufactured since 2007 when the standard was introduced. [6] Wi-Fi Protected Setup allows access points to be set up simply by entering a PIN or other identification into a connection screen, or in some cases, simply by pressing a button. The Protected Setup system uses this information to send data to a computer, handing it the information needed to complete the network setup and connect to the Internet. From the user's point of view, a single click replaces the multi-step, jargon-filled setup experience formerly required.
While the Protected Setup model works as intended, it was intended only to simplify the connection between the access point and the devices that would make use of its services, primarily accessing the Internet. It provides little help within a network - finding and setting up printer access from a computer for instance. To address those roles, a number of different protocols have developed, including Universal Plug and Play (UPnP), Devices Profile for Web Services (DPWS), and zero-configuration networking (ZeroConf). These protocols allow devices to seek out other devices within the network, query their capabilities, and provide some level of automatic setup.
Wi-Fi Direct has become a standard feature in smart phones and portable media players, and in feature phones as well. [7] The process of adding Wi-Fi to smaller devices has accelerated, and it is now possible to find printers, cameras, scanners, and many other common devices with Wi-Fi in addition to other connections, like USB.
The widespread adoption of Wi-Fi in new classes of smaller devices made the need for ad hoc networking much more important. Even without a central Wi-Fi hub or router, it would be useful for a laptop computer to be able to wirelessly connect to a local printer. Although the ad hoc mode was created to address this sort of need, the lack of additional information for discovery makes it difficult to use in practice. [8] [9]
Although systems like UPnP and Bonjour provide many of the needed capabilities and are included in some devices, a single widely supported standard was lacking, and support within existing devices was far from universal. A guest using their smart phone would likely be able to find a hotspot and connect to the Internet with ease, perhaps using Protected Setup to do so. But, the same device would find that streaming music to a computer or printing a file might be difficult, or simply not supported between differing brands of hardware.
Wi-Fi Direct can provide a wireless connection to peripherals. Wireless mice, keyboards, remote controls, headsets, speakers, displays, and many other functions can be implemented with Wi-Fi Direct. This has begun with Wi-Fi mouse products, and Wi-Fi Direct remote controls that were shipping circa November 2012.
File sharing applications such as SHAREit on Android and BlackBerry 10 devices could use Wi-Fi Direct, with most Android version 4.1 (Jellybean), introduced in July 2012, and BlackBerry 10.2 supported. Android version 4.2 (Jellybean) included further refinements to Wi-Fi Direct including persistent permissions enabling two-way transfer of data between multiple devices.
The Miracast standard for the wireless connection of devices to displays is based on Wi-Fi direct.[ citation needed ]
Wi-Fi Direct essentially embeds a software access point ("Soft AP") into any device that must support Direct. [8] The soft AP provides a version of Wi-Fi Protected Setup with its push-button or PIN-based setup.
When a device enters the range of the Wi-Fi Direct host, it can connect to it, and then gather setup information using a Protected Setup-style transfer. [8] Connection and setup is so simplified that it may replace Bluetooth in some situations. [10]
Soft APs can be as simple or as complex as the role requires. A digital picture frame might provide only the most basic services needed to allow digital cameras to connect and upload images. A smart phone that allows data tethering might run a more complex soft AP that adds the ability to bridge to the Internet. The standard also includes WPA2 security and features to control access within corporate networks. [8] Wi-Fi Direct-certified devices can connect one-to-one or one-to-many and not all connected products need to be Wi-Fi Direct-certified. One Wi-Fi Direct enabled device can connect to legacy Wi-Fi certified devices.
The Wi-Fi Direct certification program is developed and administered by the Wi-Fi Alliance, the industry group that owns the "Wi-Fi" trademark. The specification is available for purchase from the Wi-Fi Alliance. [11]
Intel included Wi-Fi Direct on the Centrino 2 platform, in its My WiFi technology by 2008. [12] Wi-Fi Direct devices can connect to a notebook computer that plays the role of a software Access Point (AP). The notebook computer can then provide Internet access to the Wi-Fi Direct-enabled devices without a Wi-Fi AP. Marvell Technology Group, [13] Atheros, Broadcom, Intel, Ralink, and Realtek announced their first products in October 2010. [14] Redpine Signals's chipset was Wi-Fi Direct certified in November of the same year. [15]
Google announced Wi-Fi Direct support in Android 4.0 in October 2011. [16] While some Android 2.3 devices like Samsung Galaxy S II have had this feature through proprietary operating system extensions developed by OEMs, the Galaxy Nexus (released November 2011) was the first Android device to ship with Google's implementation of this feature and an API for developers. [ citation needed ] Ozmo Devices, which developed integrated circuits (chips) designed for Wi-Fi Direct, was acquired by Atmel in 2012. [17] [18]
Wi-Fi Direct became available with the BlackBerry 10.2 upgrade. [19] [20]
As of March 2016, [update] no iPhone device implements Wi-Fi Direct; instead, iOS has its own proprietary feature, namely Apple's MultipeerConnectivity. [21] This protocol and others are used in the feature AirDrop, used to transfer large files between Apple devices using a similar (but proprietary) technology to Wi-Fi Direct.
The Xbox One, released in 2013, supports Wi-Fi Direct. [22]
NVIDIA's SHIELD controller uses Wi-Fi Direct to connect to compatible devices. NVIDIA claims a reduction in latency and increase in throughput over competing Bluetooth controllers. [23]
Bluetooth is a short-range wireless technology standard that is used for exchanging data between fixed and mobile devices over short distances and building personal area networks (PANs). In the most widely used mode, transmission power is limited to 2.5 milliwatts, giving it a very short range of up to 10 metres (33 ft). It employs UHF radio waves in the ISM bands, from 2.402 GHz to 2.48 GHz. It is mainly used as an alternative to wired connections to exchange files between nearby portable devices and connect cell phones and music players with wireless headphones.
A personal digital assistant (PDA), also known as a handheld PC, is a multi-purpose mobile device which functions as a personal information manager. PDAs have been mostly displaced by the widespread adoption of highly capable smartphones, in particular those based on iOS and Android, and thus saw a rapid decline in use after 2007.
A wireless LAN (WLAN) is a wireless computer network that links two or more devices using wireless communication to form a local area network (LAN) within a limited area such as a home, school, computer laboratory, campus, or office building. This gives users the ability to move around within the area and remain connected to the network. Through a gateway, a WLAN can also provide a connection to the wider Internet.
Wi-Fi 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 to provide visitors.
Wireless communication is the transfer of information (telecommunication) between two or more points without the use of an electrical conductor, optical fiber or other continuous guided medium for the transfer. The most common wireless technologies use radio waves. With radio waves, intended distances can be short, such as a few meters for Bluetooth or as far as millions of kilometers for deep-space radio communications. It encompasses various types of fixed, mobile, and portable applications, including two-way radios, cellular telephones, personal digital assistants (PDAs), and wireless networking. Other examples of applications of radio wireless technology include GPS units, garage door openers, wireless computer mouse, keyboards and headsets, headphones, radio receivers, satellite television, broadcast television and cordless telephones. Somewhat less common methods of achieving wireless communications involve other electromagnetic phenomena, such as light and magnetic or electric fields, or the use of sound.
In computer networking, a wireless access point, or more generally just access point (AP), is a networking hardware device that allows other Wi-Fi devices to connect to a wired network or wireless network. As a standalone device, the AP may have a wired connection to a switch or router, but, in a wireless router, it can also be an integral component of the router itself. An AP is differentiated from a hotspot, which is a physical location where Wi-Fi access is available.
Wi-Fi Protected Access (WPA), Wi-Fi Protected Access 2 (WPA2), and Wi-Fi Protected Access 3 (WPA3) are the three security certification programs developed after 2000 by the Wi-Fi Alliance to secure wireless computer networks. The Alliance defined these in response to serious weaknesses researchers had found in the previous system, Wired Equivalent Privacy (WEP).
The Wi-Fi Alliance is a non-profit organization that owns the Wi-Fi trademark. Manufacturers may use the trademark to brand products certified for Wi-Fi interoperability. It is based in Austin, Texas.
A hotspot is a physical location where people can obtain Internet access, typically using Wi-Fi technology, via a wireless local-area network (WLAN) using a router connected to an Internet service provider.
Tethering or phone-as-modem (PAM) is the sharing of a mobile device's Internet connection with other connected computers. Connection of a mobile device with other devices can be done over wireless LAN (Wi-Fi), over Bluetooth or by physical connection using a cable, for example through USB.
Wi-Fi calling refers to mobile phone voice calls and data that are made over IP networks using Wi-Fi, instead of the cell towers provided by cellular networks. Using this feature, compatible handsets are able to route regular cellular calls through a wireless LAN (Wi-Fi) network with broadband Internet, while seamlessly change connections between the two where necessary. This feature makes use of the Generic Access Network (GAN) protocol, also known as Unlicensed Mobile Access (UMA).
Wi-Fi Protected Setup (WPS) originally, Wi-Fi Simple Config, is a network security standard to create a secure wireless home network.
Piggybacking on Internet access is the practice of establishing a wireless Internet connection by using another subscriber's wireless Internet access service without the subscriber's explicit permission or knowledge. It is a legally and ethically controversial practice, with laws that vary by jurisdiction around the world. While completely outlawed or regulated in some places, it is permitted in others.
In computing, Microsoft's Windows Vista and Windows Server 2008 introduced in 2007/2008 a new networking stack named Next Generation TCP/IP stack, to improve on the previous stack in several ways. The stack includes native implementation of IPv6, as well as a complete overhaul of IPv4. The new TCP/IP stack uses a new method to store configuration settings that enables more dynamic control and does not require a computer restart after a change in settings. The new stack, implemented as a dual-stack model, depends on a strong host-model and features an infrastructure to enable more modular components that one can dynamically insert and remove.
SoftAP is an abbreviated term for "software enabled access point". Such access points utilize software to enable a computer which hasn't been specifically made to be a router into a wireless access point. It is often used interchangeably with the term "virtual router".
Connectify is an American software company that develops networking software for consumers, professionals and companies. Connectify Hotspot is a virtual router software for Microsoft Windows, and Speedify is a mobile VPN service with channel bonding capabilities available for individuals, families and teams.
The WIMM One is a developer device for the WIMM platform produced by WIMM Labs. It is a wearable computing device running a modified version of the Android operating system. It comes preloaded with several apps. Additional applications can be downloaded from the micro app store or side-loaded over USB.
Miracast is a wireless communications standard created by the Wi-Fi Alliance which is designed to transmit video and sound directly from devices to display receivers. It can roughly be described as "HDMI over Wi-Fi", replacing cables in favor of wireless. The protocol is utilised in many devices and is used or branded under various names by different manufacturers, including Smart View and AllShare Cast, SmartShare, screen mirroring, Cast, wireless display and screen casting.
Banana Pi is a line of single-board computers produced by the Chinese company Shenzhen SINOVOIP Company, its spin-off Guangdong BiPai Technology Company, and supported by Hon Hai Technology (Foxconn). Its hardware design was influenced by the Raspberry Pi, and both lines use the same 40-pin I/O connector.
Smartphone ad hoc networks are wireless ad hoc networks that use smartphones. Once embedded with ad hoc networking technology, a group of smartphones in close proximity can together create an ad hoc network. Smart phone ad hoc networks use the existing hardware in commercially available smartphones to create peer-to-peer networks without relying on cellular carrier networks, wireless access points, or traditional network infrastructure. Wi-Fi SPANs use the mechanism behind Wi-Fi ad-hoc mode, which allows phones to talk directly among each other, through a transparent neighbor and route discovery mechanism. SPANs differ from traditional hub and spoke networks, such as Wi-Fi Direct, in that they support multi-hop routing and relays and there is no notion of a group leader, so peers can join and leave at will without destroying the network.