esp-idf/examples/wifi/wifi_aware/nan_subscriber

Supported Targets	ESP32	ESP32-S2

NAN Subscriber 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 Subscribe method with some configuration options. Use option Example Configuration -> NAN Service Name for naming a service to subscribe to. Select Subscribe Type and optionally set the Matching Filter. Using option Communication Type it's possible to either send a message using Follow-up or initiate a datapath with the Publisher. The device will search for another device in the vicinity Publishing the same service. 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 will initiate further communication as par configuration.

Example Output

Usecase 1 : Subscriber sending a Follow-up to the Publisher

I (449) phy_init: phy_version 1800,e7ef680,Apr 13 2021,11:45:08
I (549) wifi:mode : NAN (18:fe:34:72:50:b1)
Set Vif NAN
I (549) NAN: State Init => Scanning

I (3549) NAN: Join Cluster with Id 50:6f:9a:01:cc:4d
I (3549) wifi:Init max length of beacon: 752/752
I (3549) wifi:Init max length of beacon: 752/752
I (3559) NAN: State Scanning => AnchorMaster

I (3762) nan_app: NAN Discovery started.
I (4222) nan_sub: NAN Publisher found for Serv ID 5
I (4222) nan_app: Service matched with e0:e2:e6:7b:c1:32 [Peer Publish id - 5]
I (4222) nan_sub: Sending message 'Hello' to Publisher e0:e2:e6:7b:c1:32 ...
I (4762) nan_app: Received message 'Welcome' from Peer e0:e2:e6:7b:c1:32 [Peer Service id - 5]

Usecase 2 : Subscriber setting up Datapath with the Publisher, then testing IPv6 ping

I (452) phy_init: phy_version 1800,e7ef680,Apr 13 2021,11:45:08
I (552) wifi:mode : NAN (18:fe:34:72:50:b1)
Set Vif NAN
I (552) NAN: State Init => Scanning

I (3552) NAN: Join Cluster with Id 50:6f:9a:01:cc:4d
I (3562) wifi:Init max length of beacon: 752/752
I (3562) wifi:Init max length of beacon: 752/752
I (3562) NAN: State Scanning => AnchorMaster

I (3562) nan_sub: NAN Discovery started.
I (3572) nan_sub: Subscribing to Service test with ID 5
I (3612) nan_sub: NAN Publisher found for Serv ID 5
E (3612) wifi:Committed slots 0x7fff0000 for Peer 18:fe:34:72:50:ca on Channel 6
I (3622) nan_sub: Datapath setup with 18:fe:34:72:50:ca
I (5452) nan_sub: Got IPv6 event: Interface "nan_sub: nan" address: fe80:0000:0000:0000:1afe:34ff:fe72:50b3, type: ESP_IP6_ADDR_IS_LINK_LOCAL
I (5452) nan_sub: Pinging Peer with IPv6 addr FE80::1AFE:34FF:FE72:50CA
W (5722) wifi:<ba-add>idx:5 (ifx:2, 18:fe:34:72:50:ca), tid:0, ssn:0, winSize:64
I (5742) nan_sub: 64 bytes from FE80::1AFE:34FF:FE72:50CA icmp_seq=1 ttl=0 time=278 ms
I (7462) nan_sub: 64 bytes from FE80::1AFE:34FF:FE72:50CA icmp_seq=2 ttl=0 time=2 ms
I (7462) nan_sub: 64 bytes from FE80::1AFE:34FF:FE72:50CA icmp_seq=3 ttl=0 time=2 ms
I (8462) nan_sub: 64 bytes from FE80::1AFE:34FF:FE72:50CA icmp_seq=4 ttl=0 time=1 ms
I (9462) nan_sub: 64 bytes from FE80::1AFE:34FF:FE72:50CA icmp_seq=5 ttl=0 time=1 ms
I (10462) nan_sub:
--- FE80::1AFE:34FF:FE72:50CA ping statistics ---
I (10462) nan_sub: 5 packets transmitted, 4 received, 19% packet loss, time 1281ms