WI-FI Direct

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Wi-Fi technology continue to evolve In 2013, more than two billion Wi-Fi-enabled devices shipped The market is forecast to continue to grow rapidly over the next five years as the technology is adopted across a wide variety of markets, including consumer, mobile, automotive, and emerging markets Wi-Fi is widely available in homes, Wi-Fi hotspots, and enterprise environments, and is found in many types of devices, including notebook computers, cameras, media players, photo frames, TVs, gaming devices, and mobile phones, among others. At the time of this paper's publication, Wi-Fi Alliance has over 650 member companies and has certified more than 20,000 products since march 2000 As Wi-Fi is in the middle of its second decade the members of wi-fi alliance have developed specifications to expand how consumers can use wi-Fi. Wi-Fi Direct-certified devices allow the creation of direct connections between Wi-Fi client devices without requiring the presence of a traditional Wi-Fi infrastructure network(i.e, AP or router) Devices certified to the wi-Fi Peer-to-Peer Specification and Wi-Fi Peer-to-Peer Services Specification will be able to bear the wi-Fi Direct certification mark The introduction of Wi-Fi Direct devices creates an important foundation to greatly enhance the portability of content and applications across all of a user's devices Wi-Fi Peer-to-Peer technology and service enhancements build on traditional Wi-Fi strengths like performance, security, ease of use and ubiquity, and add features that optimize it for consumer uses that don't require access to an infrastructure network Rather than connecting first to an infrastructure network and then connecting to another networked device, users can connect directly to those devices offering the services they need. This allows, for example, a user to show friends the photos on his mobile phone by connecting directly to a television and displaying the images regardless of whether an infrastructure network is available to both devices ABI Research. 2014 C 2014 Wi-Fi Alliance. All rights reserved Global Wi-Fi Direct Device Shipments (ABI Research, 2014) 4.000 3.000 2000 1.000 0 2010201120122013201420152016201720182019 ■ Devices with wi- Fi Direct■AW- Fi devices To date, more than 6000 devices have become wi-Fi Direct certified. In 2014, about 1.1 billion Wi-Fi Direct devices will ship, and Wi-Fi Direct is forecast to ship in 80 percent of all Wi-Fi devices by 2019 The enhancements created by the p2ps specification define an application service platform (ASP)and four industry-standard services that allow users to share files, stream media, and print documents -no matter what vendor made the phone, display, printer, or other device. In addition, a new APl enables developers to easily build applications that take advantage of p2P connections Wi-Fi Direct-certified devices support connection with existing legacy wi-Fi devices. In this way, a direct connection capability is possible on the billions of legacy wi-Fi CERTIFIED devices already deployed Wi-Fi Direct Devices certified for Wi-Fi Direct extend the technology's reach beyond internet connectivity to include the simple, direct connections that many users may accomplish using cables today. Some of the benefits consumers see from Wi-Fi Direct devices and standardized services include: 2 ABI Research 2014 C 2014 Wi-Fi Alliance. All rights reserved Mobility portability Wi-Fi Direct devices can connect anytime, anywhere. Since a Wi-Fi router or AP is not required, Wi-Fi P2P builds on wi-Fi's devices can be connected everywhere. traditional strengths Immediate Utility Users will have the Throughput and range of ability to create direct connections with traditional Wi-Fi technology the very first Wi-Fi Direct certified devices (up to Wi-FI CERTIFIED ac bring home Compatibility with legacy Ease of Use: Wi-Fi Direct Device Discovery Wi-Fi certified devices and service Discovery features allow users Support for 2. 4 and 5 gHz to identify available devices and services operation before establishing a connection For Flexible IP connection example, if a user would like to print, they can learn which wi-Fi networks have a WPA2TMsecurity Simple configuration Wi-Fi printer. Protected setup Simple Secure Connections: Wi-Fi Direct devices use Wi-Fi Protected Setup TM to make it simple to create secure and introduces important connections between devices. Users either new capabilities press a button on both devices, or"tap-to connect"using nfc to easily create a Automatic device discovery secure connection Pre-connection service Common task Performance: With optional discovery services, users can send files, print Enhanced power documents, play media, and display management modes screens between and among devices, no Support for multiple matter the vendor simultaneous connections New applications from third-party (concurrent connections developers: Wi-Fi Direct offers an api that Separate security domains makes it simple for developers to build for infrastructure and direct new, innovative applications for users connections Enterprise- friendly device P2P and P2Ps technology play a role anywhere a management quick connection is desired. Here are some Internet connection sharing examples of how Wi-Fi Direct devices redefine the connected experience for consumers Application service platform (ASP)implementing common Nora needs to print her term paper before functions of advertising and heading to class. Her laptop has discovery permission to access the university's Industry-standard service network but she is not allowed to connect applications her printer to the network. in her dorm room using her Wi-Fi Direct laptop, she C 2014 Wi-Fi Alliance. All rights reserved prints directly to her Wi-Fi printer while continuing to check email over the university Wi-Fi network Joe is commuting to work on the train after a once-in-a-lifetime vacation overseas He makes use of the time to transfer his photos directly from his Wi-Fi-enabled camera to his tablet and culls through them to find the best ones. After work, he visits friends and displays the photos on their Wi-Fi-enabled television Kevin has been travelling for two weeks using his netbook. When he returns to the office, he syncs the new files he has created on his netbook with his desktop Pc She goes to the hotel's business center, opens her phone's email, then taps a link Samantha is at a hotel and realizes that she needs to print her airline boarding pas The pass appears in a browser. She taps Print, then simply selects from a list of business center printers that are Wi-Fi Direct Print certified Sally and ann invite the guests at their party to use the cameras on their mobile phones to capture the party, and directly display the videos on their Wi-Fi-enabled television Kims friends Tom, John and Elizabeth come to her house after school to play video games. With Wi-Fi Direct, the group is directly connect their handheld gaming devices to engage in mortal combat, without adding traffic to the home network John prevails. Later that evening Kim connects to her home network and challenges John to a rematch over the internet In managed environments such as enterprise or hotspot networks, p2P provides simple convenient connectivity without requiring devices to join the primary WLAn. the use of wi Fi Direct avoids the additional configuration complexity and potentially exposure of network resources. a Wi-Fi Direct guest device can connect directly to a printer without having to be given access to any other network resource. all Wi-Fi Direct devices make their presence and settings known so they can be integrated into management systems. A platform for innovation Wi-Fi Peer-to-Peer technology has been designed to be implemented on the same silicon as the majority of new devices that support Wi-Fi. As a result, the new capabilities will not require a significant increase in software or cpu capabilit Wi-Fi Peer-to-Peer empowers developers to offer users anytime, anywhere connectivity and adds additional capabilities to address the needs of fully portable connections Wi-Fi Peer-to-Peer service provides optional, standardized services. These services ensure interoperability between devices from different manufacturers. In addition, the Enable apl makes it easy for vendors to build on those standard services, and it enables third-party developers to create completely new applications that take advantage of Wi-Fi P2P With a connection framework that is distinct from the applications themselves, Wi-Fi P2P makes processing efficient and offers developers a flexible way to implement designs the C 2014 Wi-Fi Alliance. All rights reserved P2P connection can be managed by the application, a management function, or even the operating system. In addition, this flexible approach avoids forcing a connection to be dedicated to a single task(which would prevent it from being used by other applications) Technology basics By definition, a Wi-Fi Direct device is capable of a peer-to-peer connection, and can support either an infrastructure or a P2P connection. Wi-Fi Direct devices have the ability to join infrastructure networks as typical stations (STAs), and must support Wi-Fi Protected Setup enrollee functionality Wi-Fi Direct devices connect by forming Groups(in a one-to-one or one-to-many topology that function in a manner similar to an infrastructure bss a single Wi-Fi direct device is in charge of the group, including controlling which devices are allowed to join and when the Group is started and terminated this device will P2P Group appear as an aP to legacy Clients, and provides some of the services commonly provided by an infrastructure AP. EXamples include: BSS functionality, Wi-Fi Protected Setup Internal Registrar functionality and communication between Clients in the Group. Optional features such as simultaneous(concurrent)connection with P2P Client an infrastructure network and sharing of that Group Owner infrastructure connection may also be provided Legacy Client Note that because wi-fi Direct devices do not duplicate the full functionality of infrastructure APs, tr aditional aPs will continue to be the best choice for meeting the needs of stationary multipurpose networks in homes hotspots and enterprises All Wi-Fi Direct devices must be capable of being in charge of a group and must be able to negotiate which device adopts this role when forming a group with another Wi-Fi Direct device. Wi-Fi Direct devices must also support mandatory discovery and Power Management mechanisms. Wi-Fi Direct devices may support optional features including Managed device mechanisms and concurrent infrastructure connections A Group may be comprised of both Wi-Fi Direct devices and legacy devices (i.e., Wi-Fi CERTIFIEd devices that are not compliant with the Wi-Fi Peer-to-Peer Specification). Legacy devices can only function as Clients within a Group C 2014 Wi-Fi Alliance. All rights reserved Key mechanisms Table 1 lists the key mechanisms defined in the wi-Fi Peer-to-Peer Specification Mandatory Optional Device discovery Mechanism to find Wi-Fi Direct devices and exchange device information Service Discovery: Mechanism to facilitate discovery of higher-layer services Can be exercised prior Ⅹ to establishing a Wi-Fi Direct device connection Group Formation Mechanism to determine which Wi-Fi Direct device is in charge of the Group Invitation Mechanism that allows a wi-fi Direct device to invite another wi-Fi Direct device to join an existing Group client Discovery Mechanism enabling a Wi-Fi Direct device to discover which Wi-Fi Direct devices are in an existing Group. Power Management P2P-PS and p2P-WMM-Power save: Adaptations of legacy power save and wMm-Power save mechanisms that enable additional savings for Wi-Fi Direct devices Notice of absence: Technique enabling a Wi-Fi Direct device that is in charge of a Group to reduce power consumption by communicating a planned absence Opportunistic Power Save: Technique enabling Wi-Fi Direct device that is in charge of a group to reduce power consumption by entering a doze state while connected Wi-Fi Direct devices are dozing Device Discovery Device Discovery is used to identify other Wi-Fi Direct devices and establish a connection. It is accomplished using a scan similar to that used to discover infrastructure APs. Users can select a discovered device for connection if the target is not already part of a group, a new Group is formed. If the target is already part of a group the searching Wi-Fi Direct device may attempt to join the existing Group Wi-Fi Protected Setup is used to obtain credentials and authenticate the searching Wi-Fi Direct device C 2014 Wi-Fi Alliance. All rights reserved Peer-to-Peer Service Discovery Service discovery is an optional feature that enables the advertisement of services supported by higher layer applications(i. e, Bonjour, UPnP, Web Service Discovery)to other Wi-Fi Direct devices. Service Discovery can be performed at any time(e.g. even before a connection is formed)with any other discovered Wi-Fi Direct device For example, if a user wants to print a photo, the printing application can identify which Wi- Fi Direct devices can provide printing services and present a compatible list of options to the user. This can prevent frustration that may arise by attempting to connect to an incompatible printer Creating a group Adding a Device to P2P Group by Invitation A Group may be created by a single Wi-Fi Direct Discovery device. This is required when connecting a P2 2P nvitation legacy device and may Provisioning be desirable when Connected creating a group to offer P2P Group owner New p2P Device a specific service e. g. Internet connection sharing. When forming a connection between two Wi-Fi Direct devices. a Group may be formed Existing P2P Device automatically; in this case the devices will negotiate to determine which device is in charge of the Group. the device in charge of the group always decides if this is a temporary (single instance)or persistent(multiple, recurring use) Group. After a group is formed, a Wi-Fi Direct device may invite another Wi-Fi Direct device to join the Group. The optional Invitation mechanism can also be used to request that a previously used persistent Group be reformed. The decision of whether or not to accept an invitation is left to the invited Wi-Fi Direct device The client discovery capability makes it easier for users to locate and connect to a specific device or device type. For example, a camera can query to see if any Wi-Fi Direct devices are printers Power Management Efficient use of power is critical for portable devices. the p2P Specification includes power management mechanisms that can reduce power consumption for devices regardless of role within a Group, while maintaining valuable discovery capabilities. While all Wi-Fi Direct devices implement these mechanisms, realization of power savings will depend on the settings and interaction between the devices in a given environment. C 2014 Wi-Fi Alliance. All rights reserved Some of the power management capabilities are based on standard wi-Fi Power Save and WMM-Power Save, with adapted mechanisms referred to as p2P-Ps and p2P-WMM-Power Save The P2P Specification introduces two new power savings mechanisms to enable a device in charge of a group to save power Opportunistic Power Save and notice of Absence. These mechanisms may be used together to maximize doze time -a particularly important capability since in many cases Wi-Fi Direct devices are battery-operated The Notice of Absence mechanism makes it possible to signal a planned absence-either single or periodic Opportunistic Power Save allows to the Wi-Fi Direct device in charge of the group to save power by entering a doze state when all connected wi-Fi Direct devices are also in a doze state to maintain device discoverability while using power Management, the Wi-Fi Direct device in charge of the group is available on a periodic basis Searching devices are aware that power save mechanisms may be in use. Power management mechanisms are available only for use in groups in which only Wi-Fi Direct devices are associated. If legacy devices are present, these power management functions cannot be employed Important capabilities Table 2 lists important capabilities introduced in the wi-Fi Peer-to-Peer Specification Mandatory Optional Persistent Groups: A mechanism that allows a previously established Group to be re- invoked at a future time without re-provisioning Concurrent Connection: Capability of a Wi-Fi Direct Device to maintain multiple connections simultaneously. Connections can be to groups and/or traditional WLAN Multiple Groups: Wi-Fi Direct Device maintains membership in multiple Groups simultaneously Cross-connection: Allows Wi-Fi Direct device in charge of a group to provide infrastructure access to other devices in the Group ersistent Groups Groups may be re-invoked for additional sessions after initial formation For example,a laptop could create a Persistent Group that comprised of the laptop and a printer that is restarted each time a print request is made if the printer is discovered. Persistent Groups may be restarted without provisioning eliminating the need to repeat tasks such as entering a Wi-Fi Protected Setup PIN. Persistent Groups are accomplished by wi-Fi Direct devices storing the Group information and credentials. Since Persistent Groups are invoked using Invitation signaling, all Wi-Fi Direct devices that support Persistent Groups must also support the Invitation mechanism C 2014 Wi-Fi Alliance. All rights reserved

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