esp-idf/examples/wifi/wifi_aware/nan_publisher

Supported Targets	ESP32	ESP32-S2

NAN Publisher Example

(See the README.md file in the upper level 'examples' directory for more information about examples.)

Introduction

Neighbor Awareness Networking (NAN) is a protocol that allows Wi-Fi devices to discover services in their proximity. NAN uses direct device-to-device communication and does not require any Internet or AP connection. Multiple NAN devices which are in the vicinity will form a NAN cluster which allows them to communicate with each other. Devices within a NAN cluster can advertise or look for services using NAN Service Discovery protocols. A Publisher advertises a service and a Subscriber searches for a service. A subscriber either listens passively (Passive mode) or sends out broadcast Action frames (Active mode). Similarly a publisher either broadcasts its services (Unsolicited mode) or replies to Active subscribers (Solicited Mode). Matching of services is done by service name and optionally matching filters.

How to use example

Publishing and Subscribing is possible dynamically on the NAN Interface. For simplicity this example demonstrates only the Publish method with some configuration options. Use option Example Configuration -> NAN Service Name for naming the Publish service. Select Publish Type and optionally set the Matching Filter and Reply message in the same menu. Another device in the vicinity running the Subscriber example will discover the Publisher. A service match happens when the service name (case insensitive) matches as well as the Matching filter(s) matche(s) (case sensitive). After this the Subscriber may send a Follow-up or initiate Datapath with the Publisher for further communication. The Publisher will send a reply to the Follow-up and will accept the Datapath request given that it has enough resources.

Example Output

Usecase 1 : Publisher with a Follow-up exchange with a Subscriber

I (449) phy_init: phy_version 1800,e7ef680,Apr 13 2021,11:45:08
I (549) wifi:mode : NAN (18:fe:34:72:50:c8)
Set Vif NAN
I (559) NAN: State Init => Scanning

I (3559) NAN: Start own Cluster, Id 50:6f:9a:01:cc:4d
I (3559) wifi:Init max length of beacon: 752/752
I (3559) wifi:Init max length of beacon: 752/752
I (3559) NAN: State Scanning => AnchorMaster

I (3794) nan_app: NAN Discovery started.
I (5604) NAN: State Master => AnchorMaster

I (8244) nan_app: Received message 'Hello' from Peer e0:e2:e6:6a:7a:fe [Peer Service id - 5]
I (8244) nan_pub: Replied 'Welcome' to the Subscriber...

Usecase 2 : Publisher accepting Datapath request by a Subscriber

I (449) phy_init: phy_version 1800,e7ef680,Apr 13 2021,11:45:08
I (559) wifi:mode : NAN (18:fe:34:72:50:c8)
Set Vif NAN
I (559) NAN: State Init => Scanning

I (3559) NAN: Join Cluster with Id 50:6f:9a:01:cc:4d
I (3559) wifi:Init max length of beacon: 752/752
I (3559) wifi:Init max length of beacon: 752/752
I (3559) NAN: State Scanning => Master

I (3559) nan_pub: NAN Discovery started.
I (3569) nan_pub: Publishing Service test with ID 5
E (18809) wifi:Committed slots 0x3fff0000 for Peer 18:fe:34:72:50:b3 on Channel 6
I (18809) nan_pub: Datapath setup with 18:fe:34:72:50:b3
I (20349) nan_pub: Got IPv6 event: Interface "nan_pub: nan" address: fe80:0000:0000:0000:1afe:34ff:fe72:50ca, type: ESP_IP6_ADDR_IS_LINK_LOCAL
W (20929) wifi:<ba-add>idx:5 (ifx:2, 18:fe:34:72:50:b3), tid:0, ssn:0, winSize:64