This document discusses the architecture of WiFi on Android devices and provides solutions for common WiFi issues. It describes the key components of the Android WiFi framework including WifiService, WifiStateMachine, WifiNative and wpa_supplicant. It also lists common WiFi issues like unreliability, unpredictability and high battery usage. Solutions proposed include using WiFi only when needed, batched and fixed size downloads, and push notifications to improve battery life and responsiveness.

1. Nanik Tolaram
nanikjava@yahoo.com
nanikjava
Diving
Inside
Wifi

2. About
● Senior Platform Engineer @ Blocksglobal
● Commercial Product
– screener.digital & lumenhealth.org
● Android Writer – magazine.odroid.com

3. Why should I care ?
● Battery life
● Bandwidth
● Responsive apps
● Happy User

4. High Level View
Youtube GMail WhatsApp Facebook
Framework
Wifi Android Layer
Linux Kernel
Wifi Hardware

5. Inside Framework
WifiService+
WifiServiceImpl
WifiStateMachine
WifiNative
com_android_server_wifi_wifinative.cpp
wifi.c (HAL)
wpa_supplicant daemon
WifiTrafficPoller
WifiWatchdogStateMachine
wpa_supplicant client library
Linux Kernel
local socket interface
Java Layer Native Layer
Youtube

6. Wifi Issues
● Unreliable
● Unpredictable
● High battery usage
● Async architecture

7. Solution
● Use when needed
● Batched download
● Fixed size download
● Push notification download

8. Android API
● JobScheduler + JobInfo
● ConnectivityManager
– android.net.conn.CONNECTIVITY_CHANGE