1. Introduction
DFS is Dynamic Frequency Selection, which is a function of using 5 GHz Wi-Fi frequencies that are generally reserved for radar, such as military radar, satellite communication, and weather radar. The DFS channels vary from country to country. The main benefit to use DFS channels is to increase the number of Wi-Fi channels. It is legally required Channel Availability Check process to prevent electromagnetic interference the 5 GHz frequency with the radar. If any radar signal detects, it will switch from DFS channel to non-DFS channel automatically(If driver have DFS support) .
2. Scope
The scope of this work is to integrate the DFS Feature in RPI reference platforms.This document covers only integration not validation.
3. Target Audience
- RDK-B Operators
- RDK-B SoC Vendors
- RDK-B OEM's
- RDK-B Application Vendors
- RDK-B System Integrators
4. Supported device
- Raspberry Pi4 32 bit
- Raspberry Pi4 64 bit
5. Supported dongle
6. Build Instructions
7. High Level Design
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8. TR-181 Data Model Parameters
| Module |
TR-181 DM parameter |
Purpose |
| CcspPandM |
dmcli eRT setv Device.DeviceInfo.X_RDKCENTRAL-COM_RFC.Feature.DFS.Enable bool true |
enable/disable the DFS feature.
By default, it should be disabled. |
| OneWifi |
dmcli eRT getv Device.WiFi.Radio.2.X_COMCAST_COM_DFSEnable |
This should be enabled after executed the above command. |
| dmcli eRT setv Device.WiFi.Radio.2.Channel uint 100 |
Setting DFS channel value |
| dmcli eRT setv Device.WiFi.ApplyRadioSettings bool true |
Applying radio settings |
dmcli eRT setv Device.WiFi.SSID.2.Enable bool false
dmcli eRT setv Device.WiFi.SSID.2.Enable bool true |
Re-enable the AP for updating the new channel value in realtek drivers. |
| dmcli eRT setv Device.WiFi.ApplyAccessPointSettings bool true |
Applying AP settings |
9. Test Procedure and Test Results
1. Enabling the DFS feature in RPI Router. By default, it's disabled.
2. Getting the current 5G Radio channel
3. Connected Client info
4.Changing the 5G channel value from non-dfs to dfs frequency
5. Re-enable the AP/Radio to update the new channel value in realtek driver
6. Connected client info with DFS frequency
Tested Image :
root@RaspberryPi-Gateway:/# cat version.txt
imagename:rdkb-generic-broadband-image_rdk-next_20240605110458
BRANCH=rdk-next
YOCTO_VERSION=kirkstone
VERSION=5.06.05.24
SPIN=0
BUILD_TIME="2024-06-05 11:04:58"
Generated on Wed Jun 05 11:04:58 UTC 2024
root@RaspberryPi-Gateway:/#
10. Feature Validation
TBD - We didn't validate this feature with RADAR signals .
11. Limitations
This rtl88x2bu driver doesn't have the channel switch support. So, we need to do the re-enable of AP/Radio whenever we switching the new channel .
12. References
REFPLTB-2925 - Getting issue details... STATUS
