Silicon Labs RS9116N User Manual

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AN1287: RS9116N Wi-Fi Roaming Application Note

Version 0.4
10/21/2020

AN1287: RS9116N Wi-Fi Roaming Application Note

Version 0.4

silabs.com | Building a more connected world. 2 | Page

Table of Contents

1 Abstract ......................................................................................................................................................................... 3

2 Introduction .................................................................................................................................................................. 4

3 Terminology (Acronyms/Abbreviations) .................................................................................................................... 5

4 Requirements ............................................................................................................................................................... 6

5 Background Scanning ................................................................................................................................................. 7

6 Roaming ................................................................................................ ................................................................ ........ 8

7 Configuration Steps Required for Roaming ............................................................................................................... 9

7.1 Configuration Parameters in .config File ................................................................................................................ 9

7.1.1 Access Point Configuration: ........................................................................................................................ 9

7.2 Configuring Bgscan Parameters in sta_settings.conf File .................................................................................... 10

7.3 Configuring background scan parameters through debugfs ................................................................................. 11

7.4 Configure Connection Quality Monitoring (cqm) rssi and hysteresis using iw Command ..................................... 12

7.5 Illustration of Roaming .......................................................................................................................................... 13

8 Test Procedure ........................................................................................................................................................... 14

8.1 Block Diagram ...................................................................................................................................................... 14

8.2 Description ........................................................................................................................................................... 15

8.3 Procedure ............................................................................................................................................................. 15

8.4 Results ................................................................................................................................................................. 15

9 Troubleshooting ......................................................................................................................................................... 16

10 References and Related Documentation .................................................................................................................. 17

11 Revision History ......................................................................................................................................................... 18

AN1287: RS9116N Wi-Fi Roaming Application Note

Version 0.4

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1 Abstract

This Document helps the user with the Bgscan and Roaming features supported by the RS9116N driver. It also describes
the procedure to enable Bgscan and Roaming using RS9116N driver.

AN1287: RS9116N Wi-Fi Roaming Application Note

Version 0.4

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2 Introduction

RS9116N Open Source Driver (OSD) is a SoftMAC driver which interacts with the Linux wireless MAC layer, i.e.,
MAC80211. The driver is a group of simple and efficient kernel modules which currently supports RS9116N chipsets and it

can be ported to any embedded platform in-addition to x86 platform.

Background scanning helps to get the information about surrounding AP’s in the vicinity of STA. This information helps the

STA to roam between the APs. The document explains the steps to enable Background scanning & Roaming with OSD
driver in STA mode.

AN1287: RS9116N Wi-Fi Roaming Application Note

Version 0.4

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3 Terminology (Acronyms/Abbreviations)

1. NL80211 - nl80211 is the new 802.11 netlink interface public header.

2. Bgscan - Background scanning

3. AP - Access Point

4. STA - Station DUT

5. EVB - Evaluation Board

6. EVK – Evaluation Kit

AN1287: RS9116N Wi-Fi Roaming Application Note

Version 0.4

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4 Requirements

• RS9116N EVK – Refer to the sample product link of our module given below:

▪ https://www.silabs.com/wireless/wi-fi/rs9116-wi-fi-transceiver-modules

• WLAN driver – RS9116N n-Link Open Source Driver. Available at below link.

▪ https://www.silabs.com/wireless/wi-fi/rs9116-wi-fi-transceiver-modules

• Linux PC (kernel version v2.6.38 – v5.3)

• At least two Access points