1 Introduction

  • Article

The Wi-Fi Direct (WFD) Application to Application Protocol (WFDA2A) enables two or more devices to establish a direct connection without requiring an intermediary, such as an infrastructure wireless access point (WAP). To establish the connection, the proximate devices are required to already be running the same application. The connection is established via one of the following relationships:

  • Peer-to-peer: A single WFD connection between two applications where both are performing the role of a peer.

  • Host-to-client: An application performing the role of the host that supports WFD connections with multiple applications performing the role of a client. Although a host can connect to multiple clients, a client can only connect to one host.

The peer, host, and client roles are specific to the application and are different from the initiator and recipient roles for the data link layer (L2) and the server and client roles for the network layer (L3).

Applications advertise and search for applications on proximate devices by using specific frames, the format of which is defined by the Wi-Fi Peer-to-Peer (P2P) Specification v1.2 (WFP2P) [WF-P2P1.2]. Devices connect by using specific messages, the format of which is defined by the Wi-Fi Simple Configuration Technical Specification v2.0.2 (WFSimple) [WF-WSC2.0.2]. Devices confirm the wireless connection by exchanging a session ID created during the connection.

This document refers to the detailed specifications defined in the WFP2P [WF-P2P1.2] and the WFSimple [WF-WSC2.0.2] documents and provides application-specific message formats and descriptions to explain how the WFDA2A Protocol fits into the overall framework.

Sections 1.5, 1.8, 1.9, 2, and 3 of this specification are normative. All other sections and examples in this specification are informative.