Automatic Frequency Coordination

Lower Power V.S. Standard Power

Low Power

The Access Points in this device class can operate strictly indoors and must be equipped with only internal antennas. The FCC defines the power level by a Power Spectral Density of 5 dBm/MHz. This allows APs to transmit at 18 dBm for a 20 MHz channel, 21 dBm for 40 MHz channel, 24 dBm for 80 MHz and 27 for 160 MHz channel.  These APs can operate in the entire 1200 MHz of spectrum with a max EIRP of 30 dBm.

Standard Power

The access points in this device class can operate indoors or outdoors with an internal or external antenna. The FCC defines  Power Spectral Density at 23 dBm/MHz and a max EIRP of 36 dBm. Since these APs operate at a higher level, they can potentially interfere with the licensed 6 Ghz services operating within the spectrum. As a result, they are required to operate under the control of Automatic Frequency Coordination provider. the AFC provider serves as an independent central entity that allocates the channel and power levels based on the geolocation of the access points.

Bandwidth	PSD max for LPI	PSD max for SP	EIRP max for LPI	EIRP max for SP
20 MHz	5 dBm/MHz	23 dBm/MHz	18 dBm	36 dBm
40 MHz	5 dBm/MHz	23 dBm/MHz	21 dBm	36 dBm
80 MHz	5 dBm/MHz	23 dBm/MHz	24 dBm	36 dBm
160 MHz	5 dBm/MHz	23 dBm/MHz	27 dBm	36 dBm

Client Devices

As per the FCC regulations, the client devices must operate 6 dB lower than the power level of the AP to which it's associated.

AFC Operation

Automated Frequency Coordination System is a cloud-based operator (Example: Federated Wireless, Open AFC) that has access to FCC’s 6 GHz, incumbent database, which stores geolocation coordinates and power of these licensed wireless services operating in the 6 GHz spectrum. In order to avoid interference the access point must present its geolocation coordinates to the AFC provider when powering on and before powering on the 6 GHz radio.

For cloud-based deployments, dashboard will serve as a proxy to the AP by requesting location information to pass to the Meraki AFC provider (Federated Wireless). Upon receiving the request, the AFC provider will query its database to see if there is an overlap of a licensed 6 GHz service in that geolocation.  Based on its computed results, the AFC will send a response to the Dashboard on the channels and the power levels the AP can operate at. 

AutoRF in Dashboard will then use this information to set the correct transmit power for channels for the AP. Dashboard administrators can also choose channels with knowledge of what power limits the channels have been provided by AFC. For every access point transmitting in the 6 GHz band at Standard power will need to have its AFC data refreshed once a day (every 24 hours) to stay in FCC compliance.

Indoor access points that fail to renew their AFC status must decrease the TX power of their 6 GHz radio to operate at Indoor Low Power levels. The FCC’s regulation on 6 GHz Wi-Fi allows indoor devices to operate in the full 6 GHz band (at ‘Indoor Low Power’ or ILP) without an active AFC status.

Outdoor access points that fail to renew their AFC status must shut down the 6 GHz radio. Per regulation, the FCC only authorizes outdoor 6 GHz transmission at Standard Power and only under U-NII-5 and U-NII-7 bands.

AP Geolocation

As per the FCC regulation, access points operating at Standard Power must automatically obtain geolocation coordinates using an external or internal GPS module. To automatically obtain the geolocation of an access point, Cisco Wireless has developed a proprietary GPS module that attaches to the USB port of select MR and CW model access points. Once installed, position the access point on the floor of a building near a window with a clear line of sight to the sky. The GPS module will then be able to acquire a satellite signal and share the AP's location with dashboard.

Geolocation Propagation

Access points enabled for Standard Power do not need an embedded or USB-attached GPS module. If at least one nearby access point has a valid GPS signal, other neighboring access points can leverage the same GPS coordinates with a relative measure of uncertainty. This process is known as geolocation propagation and can be accomplished either through wired proximity on the same layer 2 switch stack or share RF neighborship up to a calculated distance of up to 400 meters from an AP with a valid GPS signal. 

In the two scenarios below, a location algorithm determines the relative position of the access point with a derived GPS location to the access point with a GPS module reporting GPS coordinates to dashboard (anchor AP).

Neighboring AP is able to see an anchor AP as its neighbor and can hear beacon frames on any band/ radio.

Neighboring AP is connected to the same dashboard-managed switch or switch stack as an anchor AP with the GPS module.

Firmware Requirements 

AFC is available in MR30.7+

Compatible AP Models

Wi-Fi 6E indoor access points

• MR57
• CW9162
• Cw9164
• CW9166
• CW9166D1

Wi-Fi 6E outdoor access points 

• CW9163E

CW-ACC-GPS1 Deployment

• Compatible with AP models with built-in USB port, i.e. MR57, CW9162, CW9164, CW9166I

• TCP Port Number 443 has to be open in the corporate firewall. 

• Access Points (at least 1 or 2) need to be mounted at a location where it can obtain satellite signals (e.g., near a window). 

Installation   

1. Insert the GPS module into the USB port of the access point.

2. Ensure the USB port is receiving power via dashboard.

GNSS Antenna Installation 

APs installed further away from a window can extend satellite reception by 3 meters by utilizing the CW-ANT-GPS1-M-00 GNSS antenna.

1. Insert the CW-ACC-GPS1 GPS module into the USB port of the access point.
2. Remove the covering on the GPS module to reveal the GNSS port and insert the antenna. 
3. Determine the desired placement of the antenna bracket on a window pane that allows for a clear line of sight to the sky.
4. Apply the adhesive strips to the top and bottom portions of the bracket.
5. Apply adhesive strips to the inside of the bracket to secure the antenna.
6. Insert the antenna into the bracket and ensure proper adhesion to the strips.
7. Clip the outer casing to the bracket and thread the cabling through the case opening.

Mounting the AP

1. Ensure the AP is mounted where the GPS module can obtain the satellite signal (e.g., near a window).

AFC Configuration

1. Navigate to Wireless > Configure > Radio settings > RF profiles.

2. Edit the default or custom RF profile the APs are assigned to in the network.

3. Under the 6 GHz radio settings, enable Standard Power service.

 

4. Click Set height for APs to manually set the height parameter of APs in the network.

5. Click on Set height.

6. Enter the approximate height from the ground level to the AP’s mounting location.

7. Select a height accuracy range from the drop-down menu.

8. Save the configuration

10. Click Done once the height is set for all APs assigned to the RF profile.

Verify AFC Status

1. Navigate to the Access Point list, and select an AP that is now enabled for AFC.

2. From the AP’s overview page, select the AFC tab.

AFC Status

The AFC overview page shows the current AFC status of an AP. A status of active means a successful request to the AFC provider along with the associated response. The AFC status page includes the target expiration time at which the current AFC response expires. Per FCC regulation, every AP operating in 6 GHz, AFC status needs to be refreshed once a day (every 24 hours).

Power Mode

After enabling AFC and verifying that Standard Power (SP) operation is permitted on specific 6 GHz channels in the access point's geographic location, the AP will switch its 6 GHz radios to Standard Power (SP) mode. This power mode allows for an Equivalent isotropic radiated power (EIRP) of up to 36 dBm or a max Power Spectral Density (PSD) of 23 dBm/MHz for the FCC regulatory domain on an eligible channel.

AFC Defined AP Location

The Location type specifies how the AP’s geographical location is determined.
If an AP has a GPS module either internally or externally and it has acquired a signal from a satellite, the Location type will indicate "GNSS" (Global Navigation Satellite System), along with the latitude and longitude coordinates of the AP. This indicates that the GPS module has recorded the positioning of the AP locally,

If the location type is reported as "Derived" it means that the location was not obtained locally via a GPS module, but rather through wired or wireless geolocation propagation with a neighboring AP.

If the Location type is empty, AFC operation is not allowed or otherwise impossible as neither GPS nor wired/wireless propagation was successful or invoked (i.e., if AFC is disabled, no valid GPS signal, the USB port is down, etc.).

Channel Availability

The channel availability is displayed in a chart view showing the power levels assigned by the AFC provider across the 6 GHz spectrum based on the AP's location and installation height. In Dashboard, AutoRF uses these power limits shared by the AFC provider to set the appropriate transmit power of the AP. The power table and channel assignment for the 6 GHz radio needs to be updated dynamically every 24 hours to comply with FCC regulations. This process ensures that APs broadcasting in 6 GHz at Standard Power do not interfere with licensed 6 Ghz services (i.e. microwave P2P links, satellite links, etc.).

Transmit Power Levels

Please note TX power levels listed within the AP details page are the base transmit power levels of the AP’s radios and do not include the TX gain from attached antennas.

 

AFC Refresh

Dashboard administrators can refresh the AFC status of selected APs. This tool will queue the AP to issue a new available spectrum inquiry request to the AFC service provider (i.e., Federated Wireless). Within a few moments of selecting this option, the current "afc_expires_at" and "afc_updated_at" timers should be refreshed and updated once an Available Spectrum Inquiry Response has been received.

 

1. Navigate Wireless > Configuration > Radio Settings.

2. Select the checkbox next to one or more AFC-capable APs in the 6 GHz radio list.

2. Click the Refresh AFC at the top of the page.

Monitoring & Troubleshooting

AFC enabled but not configured properly

The following are some considerations and steps to bring up and validate that GPS is working on a given access point:

1. Confirm a secure connection of CW-ACC-GPS1 module to the USB port of the access point's USB port.

1. Reboot the access point, and ensure that the AP is fully powered (e.g. 802.3at / PoE)

2. Ensure that AFC is enabled on the RF Profile associated with the AP in question and that the AP height and uncertainty values are accurately configured in Dashboard.

3. Verify that the AP recognizes the GPS module for use with AFC:

AFC not supported:

1. Firmware does not support SP
2. AP is not SP capable/6GHz capable
3. Network is not set to the correct regulatory domain
4. For APs with flex 5/6 radio, flex radio set to 5 GHz (no 6 GHz radios)

For the above reasons, the AFC tab on the AP details page will not show up

AFC API Endpoints:

Configuration	API Endpoint	Details
AFC Enable/Disable	PUT /networks/{networkId}/wireless/rfProfiles/{rfProfileId}	Enable or Disable AFC at RF profile level. APs are then assigned to the RF profile
Height	PUT /devices/{serial}/wireless/radio/afc/positioning	Configure height at AP Level
Height Uncertainty	PUT /devices/{serial}/wireless/radio/afc/positioning	Configure height uncertainty at AP Level
Cable Length	PUT /devices/{serial}/wireless/radio/afc/positioning	Configure cable length at AP Level
AFC Refresh	POST /devices/{serial}/wireless/radio/afc/refresh	Queues the AP for an AFC refresh to override the 22 hour refresh
Monitoring	API Endpoint
AFC Status	GET /devices/{serial}/wireless/radio/afc/powerLimits GET /organizations/{organizationId}/wireless/radio/afc/powerLimits/byDevice	Get status of most recent AFC response for device or for whole organization (can filter with list of network IDs)
Power Mode	GET /devices/{serial}/wireless/radio/status	Get radio’s power mode (SP or LPI or Off) per AP
Last Response	GET /devices/{serial}/wireless/radio/afc/powerLimits GET /organizations/{organizationId}/wireless/radio/afc/powerLimits/byDevice	Get info on most recent AFC response (expiration time, power limits, etc.) by AP or by organization (can filter with list of network IDs)