Wi-Fi Direct , originally called Wi-Fi P2P, is a standard Wi-Fi device that makes it possible to connect easily without the need for a wireless access point. Wi-Fi Direct allows two devices to establish a Wi-Fi connection instantly without the need for a wireless router. Therefore, Wi-Fi Direct is single hop radio communication instead of multihop wireless communication, unlike wireless ad hoc networks and mobile ad hoc networks. The Wi-Fi ad-hoc mode, however, supports multi-hop radio communications, with medium Wi-Fi nodes as relay packages.
Wi-Fi is becoming a way of communicating wirelessly, much like Bluetooth. This is useful for everything from internet browsing to file transfer, and for communicating with one or more devices simultaneously at typical Wi-Fi speeds. One of the advantages of Wi-Fi Direct is the ability to connect devices even if they come from different manufacturers. Only one of these Wi-Fi devices must comply with Wi-Fi Direct to create a peer-to-peer connection that transfers data directly between them with a greatly reduced setting.
Wi-Fi Direct negotiates links with the Protected Wi-Fi Setup system that sets each device's wireless access point is limited. "Installation" of Wi-Fi Direct devices can be set to require near-field communications proximity, Bluetooth signals, or keystrokes on one or all devices.
Video Wi-Fi Direct
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Wi-Fi Dasar
Conventional Wi-Fi networks are usually based on the presence of a controller device known as a wireless access point. These devices typically incorporate three main functions:
- Physical support for wireless and wired networks
- Bridge and route between devices on a network
- Service provision to add and remove devices from the network.
Typical Wi-Fi home networks include laptops, tablets and phones, devices like modern printers, music and television sets. The majority of Wi-Fi networks are set up in "infrastructure mode", where access points serve as a central hub where Wi-Fi enabled devices are connected. Devices do not communicate directly with each other (that is, in " ad-hoc " mode), but they are through the access point. Wi-Fi Direct devices can communicate with each other without the need for special wireless access points. Wi-Fi Direct devices negotiate when they first connect to determine which devices will act as access points.
Automatic settings
With the increase in the number and type of devices attached to Wi-Fi systems, the basic model of a simple router with a smart computer becomes increasingly tense. At the same time, the ever-increasing sophistication of hot spots presents regulatory issues for users. To solve this problem, there are many attempts to simplify certain aspects of the assignment task.
A common example is the Wi-Fi Protected Setup system included on most access points built since 2007 when the standard was introduced. Wi-Fi Protected Setup allows access points to be set only by entering a PIN or other identification to the connection screen, or in some cases, simply by pressing a button. The Protected Setup System uses this information to send data to the computer, submitting the information necessary to complete network settings and connect to the Internet. From a user point of view, a single click replaces the multi-step settings experience, filled with the previously required jargon.
While the Protected Setup model works as intended, it is intended only to simplify connections between access points and devices that will use its services, especially accessing the Internet. This provides a little help within the network - searching and managing printer access from a computer for example. To address these roles, a number of different protocols have been developed, including Universal Plug and Play (UPnP), Device Profile for Web Services (DPWS), and Zero Configuration Networking (ZeroConf). This protocol allows devices to search for other devices on the network, inquire about their capabilities, and provide some level of automatic settings.
New usage
Wi-Fi Direct has become a standard feature in smartphones and portable media players, and on feature phones as well. The process of adding Wi-Fi to smaller devices has been accelerated, and it's now possible to find printers, cameras, scanners and many other common devices with Wi-Fi in addition to other connections, such as USB.
Widespread adoption of Wi-Fi in new classes of smaller devices makes the need for ad hoc networks much more important. Even without a central Wi-Fi hub or router, it will be useful for laptop computers to connect wirelessly to local printers. Although the ad hoc mode was created to address this kind of need, the lack of additional information for the invention makes it difficult to use in practice.
Although systems like UPnP and Bonjour provide many of the required capabilities and are included in some devices, a widely supported standard is lacking, and support in existing devices is far from universal. A guest using their smart phone is likely to be able to spot hot spots and connect to the Internet easily, perhaps using the Protected Settings to do so. But the same device will find streaming music to a computer or printing files may be difficult, or just not supported between different hardware brands.
Wi-Fi Direct can provide wireless connections to peripherals. Wireless mouse, keyboard, remote control, headset, speaker, display and many other functions can be implemented with Wi-Fi Direct. It has started with Wi-Fi mouse products, and Wi-Fi Direct remote control delivered around November 2012.
File sharing apps on Android devices and BlackBerry 10 can 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) includes further improvements to Wi-Fi Direct including persistent permissions that enable two-way data transfers between multiple devices.
The Miracast standard for device wireless connection to display is based on Wi-Fi instantly.
Maps Wi-Fi Direct
Technical description
Wi-Fi Direct basically embeds software access point ("Soft AP"), to any device that should support Direct. Soft AP provides Wi-Fi Protected Setup version with push-button or PIN-based settings.
When a device enters the Wi-Fi Direct host range, it can connect to it, and then collects settings information using Protected Setup style transfers. Connections and settings are greatly simplified so as to replace Bluetooth in some situations.
Soft AP can be as simple or as complex as the required role. Digital photo frames may only provide the most basic services required for digital cameras to connect and upload images. Smart phones that allow data retouching can run more complex software APs that add the ability to bridge to the Internet. This standard also includes the security and features of WPA2 to control access within the corporate network. Direct-certified Wi-Fi devices can connect one-to-one or one-to-many products and not all connected products must be Wi-Fi Direct certified. One device that supports Wi-Fi Direct can connect to older Wi-Fi certified devices.
The Wi-Fi Direct certification program is developed and maintained by the Wi-Fi Alliance, an industry group with the trademark "Wi-Fi". Specifications are available for purchase from the Wi-Fi Alliance.
Commercialization
Laptop
Intel incorporated Wi-Fi Direct on the Centrino 2 platform, in its WiFi technology in 2008. The Wi-Fi Direct device can connect to notebook computers that play the role of Access Point (AP) software. The notebook computer can then provide Internet access to Direct-enabled Wi-Fi devices without Wi-Fi AP. Marvell Technology Group, Atheros, Broadcom, Intel, Ralink and Realtek announced their first product in October 2010. The Redpine Signals Chipset is certified Wi-Fi Direct in November of the same year.
Mobile devices
Google announced Wi-Fi Direct support in Android 4.0 in October 2011. While some Android 2.3 devices such as Samsung Galaxy S II have this feature through an exclusive operating system extension developed by OEMs, Galaxy Nexus (released November 2011) is the first Android device to send with the application of this feature and application programming interfaces for developers to Google. Ozmo Devices, which develops integrated circuits (chips) designed for Wi-Fi Direct, was acquired by Atmel in 2012.
Wi-Fi Direct becomes available with 10.2 Blackberry upgrade.
As of March 2016, no iPhone device implements Wi-Fi Direct; instead, iOS has its own proprietary feature, Apple's MultipeerConnectivity.
Game console
Xbox One, released in 2013, supports Wi-Fi Direct.
The NVIDIA SHIELD controller uses Wi-Fi Direct to connect to compatible devices. NVIDIA claims reduced latency and increased throughput through a competing Bluetooth controller.
Television
In March 2016 Sony, LG, Philips, and X.VISION have implemented Wi-Fi Direct on some of their televisions.
See also
- Digital Life Network Alliance
- TDLS
- Miracast
References
Source of the article : Wikipedia
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