Patent Publication Number: US-9418372-B2

Title: Advertising, discovering, and using services through virtual access point interfaces

Description:
BACKGROUND 
     1. Field 
     The disclosed embodiments relate to wireless networks. More specifically, the disclosed embodiments relate to techniques for advertising and using services on electronic devices through virtual access point interfaces on the electronic devices. 
     2. Related Art 
     Recent improvements in computing power and wireless networking technology have significantly increased the capabilities of electronic devices. For example, laptop computers, tablet computers, portable media players, smartphones, digital media receivers, video game consoles, and/or other modern electronic devices are typically equipped with WiFi capabilities that allow the electronic devices to retrieve webpages, stream audio and/or video, share desktops and/or user interfaces (UIs), and/or transfer files wirelessly among one another. 
     However, conventional wireless networking technology may require the use of preexisting access points, cellular radio towers, and/or other structured networks to connect electronic devices to each other and/or the Internet. As a result, network traffic and/or communication between two electronic devices may be limited by the availability, bandwidth, signal strength, latencies, and/or capabilities of structured network components used to transmit the network traffic. 
     On the other hand, modern electronic devices may be capable of forming wireless ad hoc networks that bypass the use of access points, cellular towers, and/or structured networks to transmit network traffic among nodes of the wireless ad hoc networks. Instead, the electronic devices may use the wireless ad hoc networks to communicate directly with one another, thereby increasing throughput and/or removing limitations associated with transmitting data through the access points and/or structured networks. Consequently, communication among electronic devices may be facilitated by mechanisms for increasing the use of wireless ad hoc networks by the electronic devices. 
     SUMMARY 
     The disclosed embodiments provide a system that provides a service on a first electronic device. During operation, the system uses a virtual access point interface and a discovery protocol to advertise the service on the first electronic device. The virtual access point interface may enable discovery of the service by a second electronic device without an infrastructure connection between the first and second electronic devices. Next, the system uses the virtual access point interface to establish a wireless peer-to-peer connection between the first electronic device and a second electronic device. Finally, the system provides the service to the second electronic device through the wireless peer-to-peer connection. 
     In some embodiments, the system also disables the virtual access point interface upon detecting a termination of advertising for the service. 
     In some embodiments, the system also uses the infrastructure connection to provide the service to the second electronic device if the infrastructure connection is more robust (e.g., has higher signal strength, greater bandwidth, etc.) than the wireless peer-to-peer connection. 
     In some embodiments, the system also scans for one or more electronic devices in proximity to the first electronic device. Upon detecting the one or more electronic devices in proximity to the first electronic device, the system uses the discovery protocol to obtain a set of services advertised by the one or more electronic devices. For example, the system may browse for and/or discover services advertised by nearby electronic devices while advertising the service on the first electronic device. 
     In some embodiments, using the discovery protocol and the virtual access point interface to advertise the service on the first electronic device includes:
         (i) enabling the virtual access point interface in response to an advertising request for the service from an application providing the service; and   (ii) upon receiving a discovery request from the second electronic device through the virtual access point interface, transmitting a discovery response to the discovery request through the virtual access point interface, wherein the discovery response is used by the second electronic device to access the service.       

     In some embodiments, the advertising request includes a request to advertise the service using a non-infrastructure mechanism. 
     In some embodiments, the discovery request includes one or more service offerings (e.g., advertised services) on the second electronic device. Each of the service offerings may include an advertised identifier for the service offering and data associated with the service offering. The discovery request may enable discovery of the service offering(s) by the first electronic device without requiring the first electronic device to transmit a separate discovery request to the second electronic device and receiving a discovery response from the second electronic device. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  shows a schematic of a system in accordance with the disclosed embodiments. 
         FIG. 2  shows a system for providing a service on an electronic device in accordance with the disclosed embodiments. 
         FIG. 3  shows a discovery request and a discovery response in accordance with the disclosed embodiments. 
         FIG. 4  shows a flowchart illustrating the process of providing a service on a first electronic device in accordance with the disclosed embodiments. 
         FIG. 5  shows a flowchart illustrating the process of using a service on a first electronic device in accordance with the disclosed embodiments. 
         FIG. 6  shows a computer system in accordance with the disclosed embodiments. 
         FIG. 7  shows an exemplary system for providing a virtual access point interface in accordance with the disclosed embodiments. 
     
    
    
     In the figures, like reference numerals refer to the same figure elements. 
     DETAILED DESCRIPTION 
     The following description is presented to enable any person skilled in the art to make and use the embodiments, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present disclosure. Thus, the present invention is not limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein. 
     The data structures and code described in this detailed description are typically stored on a computer-readable storage medium, which may be any device or medium that can store code and/or data for use by a computer system. The computer-readable storage medium includes, but is not limited to, volatile memory, non-volatile memory, magnetic and optical storage devices such as disk drives, magnetic tape, CDs (compact discs), DVDs (digital versatile discs or digital video discs), or other media capable of storing code and/or data now known or later developed. 
     The methods and processes described in the detailed description section can be embodied as code and/or data, which can be stored in a computer-readable storage medium as described above. When a computer system reads and executes the code and/or data stored on the computer-readable storage medium, the computer system performs the methods and processes embodied as data structures and code and stored within the computer-readable storage medium. 
     Furthermore, methods and processes described herein can be included in hardware modules or apparatus. These modules or apparatus may include, but are not limited to, an application-specific integrated circuit (ASIC) chip, a field-programmable gate array (FPGA), a dedicated or shared processor that executes a particular software module or a piece of code at a particular time, and/or other programmable-logic devices now known or later developed. When the hardware modules or apparatus are activated, they perform the methods and processes included within them. 
     The disclosed embodiments provide a method and system for advertising, discovering, and/or using a service on an electronic device. As shown in  FIG. 1 , a number of electronic devices  110 - 112  are connected to a network  104  through network links  106 - 108  provided by devices such as wireless access points, cellular towers, and/or routers. Electronic devices  110 - 112  may correspond to personal computers, laptop computers, tablet computers, mobile phones, portable media players, digital media receivers, video game consoles, printers, scanners, and/or other network-enabled electronic devices. Network  104  may include a local area network (LAN), wide area network (WAN), personal area network (PAN), virtual private network, intranet, mobile phone network (e.g., a cellular network), WiFi network, Ethernet network, and/or other type of network with existing infrastructure (e.g., network links  106 - 108 ) that facilitates communication among electronic devices (e.g., electronic devices  110 - 112 ) connected to network  104 . 
     Electronic devices  110 - 112  may communicate with one another and/or with other electronic devices or servers through network  104 . For example, electronic device  110  may use a discovery protocol such as Bonjour (Bonjour™ is a registered trademark of Apple Inc.) to advertise services on electronic device  110  to electronic device  112  and/or other electronic devices on network  104 . In turn, electronic device  112  may use the discovery protocol and network  104  to discover (e.g., detect) the services on electronic device  110 . Finally, electronic device  112  may use the services by connecting to electronic device  110  through network  104  and accessing the services. For example, electronic device  112  may use the discovery protocol and network  104  to access services for transferring files, streaming media, printing, collaborating on documents, and/or sharing desktops on electronic device  110 . 
     However, communication between electronic devices  110 - 112  may be limited by the availability, bandwidth, and/or capabilities of network links  106 - 108  and/or network  104 . For example, each electronic device  110 - 112  may be unable to discover and/or use services on other electronic devices in the absence of a structured network (e.g., network  104 ) connecting the electronic device to the other electronic devices. 
     In one or more embodiments, electronic devices  110 - 112  include functionality to advertise, discover, and/or use services with one another in the absence of network links  106 - 108  and/or other existing network infrastructure between electronic devices  110 - 112 . As shown in  FIG. 2 , a set of electronic devices  202 - 204  may be connected through one or more network links  206  (e.g., access points, routers, cellular towers, etc.) of a structured network, such as network  102  of  FIG. 1 . Conversely, network links  206  may not be available (e.g., out of range, secured, etc.) to one or both electronic devices  202 - 204 , and electronic devices  202 - 204  may be unable to connect to one another through the structured network. 
     To enable use of a service  226  provided by an application  222  on electronic device  202  by an application  224  on electronic device  204  without communicating through network links  206  and/or other existing network infrastructure, electronic device  202  may advertise service  226  through a virtual access point interface  216  and a discovery protocol  234  (e.g., Bonjour). In turn, electronic device  204  may discover and use service  226  through discovery protocol  234  and virtual access point interface  216 . 
     In particular, a discovery apparatus  208  on electronic device  202  may receive an advertising request for service  226  from application  222 . The advertising request may include a request to advertise service  226  using a non-infrastructure mechanism. For example, the advertising request may include a flag and/or indicator for advertising service  226  through virtual access point interface  216  and/or another ad hoc peer-to-peer mechanism. Alternatively, application  222  may be unaware of the availability of virtual access point interface  216  on electronic device  202 , and the advertising request may omit the request to advertise service  226  using virtual access point interface  216 . 
     In response to the advertising request, discovery apparatus  208  and/or a communication apparatus  212  on electronic device  202  may enable virtual access point interface  216 . For example, communication apparatus  212  may activate virtual access point interface  216  after receiving the advertising request and/or a request to activate virtual access point interface  216  from discovery apparatus  208 . To create virtual access point interface  216 , communication apparatus  212  may configure a radio on electronic device  202  to operate as a “lightweight” access point and/or provide a wireless ad hoc network. 
     Communication apparatus  212  may also include functionality to connect to a structured network (e.g., through network links  206 ) while providing virtual access point interface  216 . For example, communication apparatus  212  may concurrently provide network connectivity through a connection with a WiFi network and an ad hoc mechanism for advertising service  226  through virtual access point interface  216 . 
     To advertise service  226 , discovery apparatus  208  and/or communication apparatus  212  may enable the detection of virtual access point interface  216  and/or service  226  by other electronic devices (e.g., electronic device  204 ) in proximity to electronic device  202 . For example, discovery apparatus  208  and/or communication apparatus  212  may periodically transmit a beacon frame containing information about virtual access point interface  216  and/or service  226 . The beacon frame may specify a set of capabilities, supported data rates, and/or an identifier (e.g., an 802.11 service set identifier (SSID)) for virtual access point interface  216 . The beacon frame may also include one or more information elements describing service  226 , support for discovery protocol  234 , and/or other unique attributes of virtual access point interface  216 . Discovery apparatus  208  and/or communication apparatus  212  may also receive probe request frames from the other electronic devices and transmit probe response frames containing the same information as the beacon frame to the other electronic devices. 
     As shown in  FIG. 2 , electronic device  204  may also include a discovery apparatus  210  and a communication apparatus  214 . Discovery apparatus  210  and/or communication apparatus  214  may include functionality to detect virtual access point interface  216 , even if discovery apparatus  210  and/or communication apparatus  214  do not include functionality to provide a separate virtual access point interface on electronic device  204 . For example, discovery apparatus  210  may receive a browse request from application  224  to browse and/or scan for services advertised on nearby electronic devices, such as electronic device  202 . Communication apparatus  214  may scan for the nearby electronic devices by transmitting a probe request frame on each channel of one or more 802.11 bands supported by communication apparatus  214 . During the scan, communication apparatus  214  may receive a beacon frame and/or a probe response frame on the channel used by communication apparatus  212 . Moreover, the beacon frame and/or probe response frame may include information about virtual access point  216  and/or service, as described above. 
     Next, discovery apparatus  210  and/or communication apparatus  214  may perform discovery of service  226  using information obtained during the scan for nearby electronic devices. To initiate discovery of service  226 , discovery apparatus  210  and/or communication apparatus  214  may use discovery protocol  234  to transmit a discovery request  218  for service  226  to electronic device  202 . For example, discovery apparatus  210  and/or communication apparatus  214  may transmit discovery request  218  as a Generic Advertisement Service (GAS) frame containing a browsed identifier for service  226 . The browsed identifier may be provided by application  224  in the browse request to discovery apparatus  210 . In other words, the browsed identifier may identify service  226  as a service that application  224  is interested in using. 
     In one or more embodiments, discovery request  218  also includes one or more service offerings on electronic device  204 . For example, discovery request  218  may include advertised identifiers (e.g., service types) for the service offerings, data associated with the service offerings, and/or other information that enables discovery of the service offerings by electronic device  202 . In other words, discovery request  218  may provide information about services advertised on electronic device  204  and request information about services advertised on electronic device  202  at the same time. Discovery request  218  may thus facilitate mutual and/or “symmetric” discovery of services between electronic devices  202 - 204 , as discussed in further detail below with respect to  FIG. 3 . 
     In response to discovery request  218 , discovery apparatus  208  and/or communication apparatus  212  may generate a discovery response  220  to discovery request  218 . Discovery response  220  may include data associated with service  226 . For example, discovery response  220  may include the browsed identifier (e.g., service type) for service  226 , a unique name for service  226 , and/or other information that allows electronic device  204  to sufficiently discover service  226 . Discovery apparatus  208  and/or communication apparatus  212  may then complete discovery of service  226  by electronic device  204  by transmitting discovery response  220  to electronic device  204 . 
     While service  226  is being advertised and/or discovered, discovery apparatus  208  and/or communication apparatus  212  may also perform discovery of services advertised by electronic devices in proximity to electronic device  202 , such as electronic device  204 . For example, application  222  may send a browse request to discovery apparatus  208 , and discovery apparatus  208  and/or communication apparatus  212  may scan for nearby electronic devices by sending probe request frames over a range of 802.11 channels and receiving probe response frames for the probe request frames from the nearby electronic devices. Discovery apparatus  208  and/or communication apparatus  212  may then use information from the browse request, probe response frames, and/or discovery protocol  234  to transmit discovery requests to the nearby electronic devices and receive discovery responses to the discovery requests from the nearby electronic devices. 
     Once a service (e.g., service  226 ) is discovered by an electronic device (e.g., electronic device  204 ), the service may be used by the electronic device. For example, communication apparatus  214  may use the unique name for service  226  from discovery response  220  to perform a Domain Name System (DNS) lookup of the network address, port number, and/or other configuration information for accessing service  226  on electronic device  202 . Alternatively, communication apparatus  214  may obtain the configuration information directly from discovery response  220 . Communication apparatus  214  may subsequently use the configuration information and virtual access point interface  216  to establish a wireless peer-to-peer connection  228  with electronic device  202 , and electronic device  204  may use service  226  through wireless peer-to-peer connection  228 . 
     As mentioned above, electronic devices  202 - 204  may also be connected through an infrastructure connection provided by network links  206  and/or other existing network infrastructure. If the infrastructure connection is available and associated with a more robust connection (e.g., higher signal strength, more bandwidth, etc.) than wireless peer-to-peer connection  228 , communication apparatuses  212 - 214  may use the infrastructure connection to provide service  226  to electronic device  204 . Conversely, if no infrastructure connection is available and/or the infrastructure connection is less robust than wireless peer-to-peer connection  228 , electronic device  204  may continue to use wireless peer-to-peer connection  228  to access service  226  until use of service  226  by electronic device  204  is complete. 
     Discovery apparatus  208  and/or communication apparatus  212  may also continue advertising service  226  and/or providing virtual access point interface  216  until a termination of advertising for service  226  is received from application  222 . For example, application  222  may transmit a request to terminate advertising for service  226  to discovery apparatus  208 , and discovery apparatus  208  may discontinue advertising of service  226  through virtual access point interface  216 . Communication apparatus  212  may also disable virtual access point interface  216  if no other services are being advertised through virtual access point interface  216 . 
     Consequently, virtual access point interface  216  may allow electronic devices  202 - 204  to advertise, discover, and use services (e.g., service  226 ) with one another in the absence of an infrastructure connection between electronic devices  202 - 204 . In addition, advertising of services on each electronic device may be streamlined by enabling a virtual access point interface (e.g., virtual access point interface  216 ) upon receiving advertising requests for the services instead of after negotiating with other electronic devices to select a provider of the virtual access point interface. Finally, transmission of discovery requests (e.g., discovery request  218 ) containing service offerings may enable the “symmetric” discovery of services between electronic devices  202 - 204  and reduce delays associated with conventional, “asymmetric” service discovery that requires the transmission of discovery requests and discovery responses by both electronic devices  202 - 204  to mutually discover services on electronic devices  202 - 204 . 
     Those skilled in the art will appreciate that the system of  FIG. 2  may be implemented in a variety of ways. First, discovery apparatuses  208 - 210  and communication apparatuses  212 - 214  on each electronic device  202 - 204  may be provided by the same software and/or hardware component, or discovery apparatuses  208 - 210  and communication apparatuses  212 - 214  may execute independently from one another. For example, discovery apparatuses  208 - 210  and communication apparatuses  212 - 214  may be implemented using different combinations of an application processor, a baseband processor, a multi-core processor, a single-core processor, an operating system kernel, a standalone application, and/or a driver. 
     Second, electronic devices  202 - 204  may use various techniques to advertise and discover services. For example, electronic devices  202 - 204  may use different types and/or sequences of 802.11 frames and/or other networking mechanisms to scan for other electronic devices, discover services on the other electronic devices, and/or advertise services to the other electronic devices. 
       FIG. 3  shows a discovery request  302  and a discovery response  304  in accordance with the disclosed embodiments. Discovery request  302  and discovery response  304  may allow a service on a first electronic device (e.g., electronic devices  202 - 204  of  FIG. 2 ) to be discovered by a second electronic device. As a result, discovery request  302  may be transmitted by the second electronic device to initiate discovery of the service on the first electronic device. To identify the service, discovery request  302  may include a browsed identifier  306  for the service. For example, the second electronic device may obtain a Bonjour service type for the service from an application on the second electronic device that is interested in using the service. The second electronic device may include the Bonjour service type as browsed identifier  306  in discovery request  302  to request more information about the service. 
     As shown in  FIG. 3 , discovery request  302  may also include a set of advertised identifiers  308  and a set of data  310 . As mentioned above, advertised identifiers  308  and data  310  may specify one or more service offerings (e.g., advertised services) on the second electronic device. For example, advertised identifiers  308  may be service types for the service offerings, and data  310  may include unique names for the service offerings, descriptions of the service offerings, and/or other information that enables discovery of the service offerings by the first electronic device and/or other nearby electronic devices. Furthermore, advertised identifiers  308  and data  310  may apply to service offerings that are analogous and/or related to the service, or advertised identifiers  308  and data  310  may describe a variety of service offerings on the second electronic device, including those not related to the service. 
     The first electronic device may generate discovery response  304  in response to discovery request  302  and transmit discovery response  304  to the second electronic device. Because discovery request  302  contains advertised identifiers  308  and data  310 , the first electronic device may omit the transmission of a different discovery request to the second electronic device to discover services (e.g., the service offerings) advertised by the second electronic device. 
     Like discovery request  302 , discovery response  304  may include browsed identifier  306  to identify the service being discovered. Discovery response  304  may also include data  312  associated with the service. For example, discovery response  304  may include a unique name for the service, a description of the service, a graphic (e.g., icon) related to the service, and/or other information related to discovery of the service. Once discovery response  304  is received by the second electronic device, each electronic device will have discovered one or more services on the other electronic device. 
     The first and/or second electronic devices may use information in discovery request  302  and/or discovery response  304  to use the service. More specifically, the second electronic device may use data  312  from discovery response  304  to establish a network connection (e.g., wireless peer-to-peer connection, infrastructure connection, etc.) with the first electronic device. Alternatively, the first electronic device may use data  310  from discovery request  302  to initiate the network connection with the second electronic device. Once the network connection is initiated, the first electronic device may provide the service to the second electronic device through the network connection, or the first electronic device may initiate use of an analogous and/or related service on the second electronic device. 
     For example, the first and second electronic devices may both advertise a peer-to-peer file transfer service and use discovery request  302  and discovery response  304  to perform “symmetric” discovery of the peer-to-peer file transfer service. Each electronic device may then use information from discovery request  302  and/or discovery response  304  to establish a peer-to-peer connection with the other electronic device and transfer a file over the peer-to-peer connection to the other electronic device. 
       FIG. 4  shows a flowchart illustrating the process of providing a service on a first electronic device in accordance with the disclosed embodiments. In one or more embodiments, one or more of the steps may be omitted, repeated, and/or performed in a different order. Accordingly, the specific arrangement of steps shown in  FIG. 4  should not be construed as limiting the scope of the embodiments. 
     Initially, a virtual access point interface and a discovery protocol are used to advertise the service on the first electronic device. To advertise the service, the virtual access point interface is enabled in response to an advertising request for the service from an application providing the service (operation  400 ). The virtual access point interface may be enabled by configuring a radio on the electronic device to operate as a “lightweight” access point and/or provide a wireless ad hoc network. The advertising request may include a request to advertise the service using a non-infrastructure mechanism. 
     A browse request may also be received (operation  402 ) from the application. If the browse request is received, a scan for one or more electronic devices in proximity to the first electronic device is performed (operation  404 ). The scan may occur in response to a browse request from the application to the first electronic device. In addition, the scan may be performed independently of advertising of the service for the application. During the scan, a probe request frame may be transmitted on each channel of one or more bands used for wireless communication by the first electronic device. Probe response frames to the probe request frame may then be received from one or more electronic devices in proximity to the first electronic device. Once the electronic device(s) are detected by the scan, a discovery protocol is used to obtain a set of services advertised by the electronic device(s) (operation  406 ), as discussed in further detail below with respect to  FIG. 5 . In other words, discovery of services on other electronic devices may be performed by the first electronic device at the same time as advertising of the service to the other electronic devices. If no browse request is received, scanning and/or browsing of services on other electronic devices may not be performed by the first electronic device. 
     A discovery request may be received (operation  408 ) from a second electronic device through the virtual access point interface. If a discovery request is not received, discovery of the service may not be performed. If a discovery request is received, a discovery response to the discovery request is transmitted (operation  410 ). The discovery response may contain information that allows the second electronic device to discover the service. In addition, the discovery request may include one or more service offerings on the second electronic device, thus enabling discovery of the service offering(s) on the first electronic device without transmitting a separate discovery request to the second electronic device and receiving a discovery response from the second electronic device. 
     Next, the virtual access point interface is used to establish a wireless peer-to-peer connection between the first and second electronic devices (operation  412 ), and the service is provided to the second electronic device through the wireless peer-to-peer connection (operation  414 ). For example, the second electronic device may establish the wireless peer-to-peer connection by connecting to the virtual access point interface using information in a probe response frame from the first electronic device. The second electronic device may then use information from the discovery response and the wireless peer-to-peer connection to transfer files, share desktops, collaborate on documents, stream audio and/or video, and/or perform a print job with the first electronic device. 
     An infrastructure connection between the first and second electronic devices may be available and more robust (operation  416 ) than the wireless peer-to-peer connection. For example, the first and second electronic devices may be connected through a WiFi access point with higher signal strength and/or greater bandwidth than the wireless peer-to-peer connection. If the infrastructure connection is more robust than the wireless peer-to-peer connection, the infrastructure connection is used to provide the service to the second electronic device (operation  418 ). If the infrastructure connection is not more robust than the wireless peer-to-peer connection, the wireless peer-to-peer connection may continue to be used to provide the service to the second electronic device. 
     A termination of advertising for the service may be detected (operation  420 ). For example, the termination of advertising may be detected upon receiving a request from the application to discontinue advertising the service. If termination of advertising for the service is not detected, scanning and service discovery may continue to be performed on nearby electronic devices (operations  402 - 406 ) in conjunction with advertising of the service to the electronic devices (operations  408 - 410 ) and use of the service by the other electronic devices (operations  412 - 418 ). If termination of advertising for the service is detected, the virtual access point interface is disabled (operation  422 ), and the service is no longer advertised and/or offered through the virtual access point interface. Scanning and/or browsing of services from nearby electronic devices (operations  402 - 406 ) may continue until browsing of services is also disabled on the first electronic device. 
       FIG. 5  shows a flowchart illustrating the process of using a service on a first electronic device in accordance with the disclosed embodiments. In one or more embodiments, one or more of the steps may be omitted, repeated, and/or performed in a different order. Accordingly, the specific arrangement of steps shown in  FIG. 5  should not be construed as limiting the scope of the embodiments. 
     First, a browse request containing a browsed identifier for the service is obtained on the second electronic device (operation  500 ). For example, the second electronic device may obtain the browse request from an application on the second electronic device interested in using the service on nearby electronic devices, including the first electronic device. 
     Next, a scan for one or more electronic devices in proximity to the second electronic device is used to detect the first electronic device (operation  502 ). For example, the first electronic device may be detected by transmitting a probe request on a channel used by the first electronic device and receive a probe response to the probe request from the first electronic device. 
     After the first electronic device is detected, a discovery protocol is used to transmit a discovery request containing the browsed identifier and one or more service offerings on the second electronic device to the first electronic device (operation  504 ). Each service offering may include an advertised identifier for the service offering and data associated with the service offering. The service offering(s) may allow the first electronic device to discover services advertised by the second electronic device (e.g., the service offering(s)) without transmitting a separate discovery request to the second electronic device and obtaining a discovery response from the second electronic device, unlike existing and/or conventional service discovery techniques. In other words, the service offering(s) may facilitate “symmetric” discovery of services on the first and second electronic devices, whereas other discovery mechanisms may utilize slower, “asymmetric” discovery mechanisms. 
     A discovery response to the discovery request is then received from the first electronic device (operation  506 ) and used to access the service on the first electronic device from the second electronic device (operation  508 ). For example, the discovery response may include the browsed identifier and data associated with the service. The data may allow the second electronic device to establish a network connection (e.g., wireless peer-to-peer connection, infrastructure connection) with the first electronic device and access the service through the network connection. The first electronic device may also use the data from the second electronic device&#39;s discovery request to connect to the second electronic device and use services on the second electronic device. 
       FIG. 6  shows a computer system  600  in accordance with the disclosed embodiments. Computer system  600  may correspond to an apparatus that includes a processor  602 , memory  604 , storage  606 , and/or other components found in electronic computing devices. Processor  602  may support parallel processing and/or multi-threaded operation with other processors in computer system  600 . Computer system  600  may also include input/output (I/O) devices such as a keyboard  608 , a mouse  610 , and a display  612 . 
     Computer system  600  may include functionality to execute various components of the present embodiments. In particular, computer system  600  may include an operating system (not shown) that coordinates the use of hardware and software resources on computer system  600 , as well as one or more applications that perform specialized tasks for the user. To perform tasks for the user, applications may obtain the use of hardware resources on computer system  600  from the operating system, as well as interact with the user through a hardware and/or software framework provided by the operating system. 
     In one or more embodiments, computer system  600  provides a system for providing a service on a first electronic device. The system may include a discovery apparatus that uses a virtual access point interface and a discovery protocol to advertise the service on the first electronic device. The virtual access point interface may enable discovery of the service by a second electronic device without an infrastructure connection between the first and second electronic devices. The system may also include a communication apparatus that provides the virtual access point interface and uses the virtual access point interface to establish a wireless peer-to-peer connection between the first electronic device and a second electronic device. The communication apparatus may also provide the service to the second electronic device through the wireless peer-to-peer connection. 
     In addition, one or more components of computer system  600  may be remotely located and connected to the other components over a network. Portions of the present embodiments (e.g., discovery apparatus, communication apparatus, electronic devices, etc.) may also be located on different nodes of a distributed system that implements the embodiments. For example, the present embodiments may be implemented using a number of electronic devices connected to one another through a set of wireless peer-to-peer connections and/or infrastructure connections. 
       FIG. 7  shows an exemplary system for providing a virtual access point interface  712  in accordance with the disclosed embodiments. The system may be implemented on an electronic device, such as electronic device  202  of  FIG. 2 . As shown in  FIG. 7 , the system includes an application  702  that generates an advertising request  216  for a service provided by application  702 . For example, application  702  may request advertising of a peer-to-peer file sharing service on the electronic device. 
     Application  702  may provide advertising request  216  to a multicast Domain Name System (mDNS) responder  704  that enables advertising of services by applications, and mDNS responder  704  may use a plugin  216  to transmit advertising request  216  to a peer-to-peer (P2P) supervisor  706 . Application  702 , mDNS responder  704 , and P2P supervisor  706  may all reside in user space  716  on the electronic device. 
     Next, P2P supervisor  706  may transmit a message through a vendor abstraction layer  708  (e.g., an application programming interface (API)) to a vendor-specific 802.11 driver  710 , and 802.11 driver  710  may create a new virtual access point interface  712 . For example, 802.11 driver  710  may configure an 802.11 radio on the electronic device to provide virtual access point interface  712  by acting as a “lightweight” access point to nearby electronic devices. 802.11 driver  710  may also configure the radio to connect to a structured WiFi network while providing virtual access point interface  712 . Vendor abstraction layer  708  and 802.11 driver  710  may reside in kernel space  718  on the electronic device. 
     P2P supervisor  706  may then advertise the service through beacon frames and/or probe response frames that are transmitted from virtual access point interface  712  to nearby electronic devices. P2P supervisor  706  may also receive discovery requests from the electronic devices through virtual access point interface  712 , generate discovery responses to the discovery requests, and send the discovery responses to the discovery requests through 802.11 driver  710  and/or virtual access point interface  712 . Finally, P2P supervisor  706  may send discovery requests to the electronic devices and receive discovery responses containing services advertised by the electronic devices. 
     To use the service provided by application  702 , a second electronic device may establish a wireless P2P connection with the electronic device through virtual access point interface  712  and transmit packets through virtual access point interface  712  and a network stack  714  on the electronic device to application  702 . Application  702  may also use the wireless P2P connection, network stack  714 , and virtual access point interface  712  to transmit packets to the second electronic device, thus providing the service to the second electronic device. Finally, an infrastructure connection between the two electronic devices may be used to provide the service to the second electronic device if the infrastructure connection is available and more robust than the wireless P2P connection. 
     The foregoing descriptions of various embodiments have been presented only for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the forms disclosed. Accordingly, many modifications and variations will be apparent to practitioners skilled in the art. Additionally, the above disclosure is not intended to limit the present invention.