[New Feature - 5.7.0] ePMP - Automated Frequency Coordination (AFC)

[Fedor]

Affected platforms: ePMP4600, ePMP4600L, Force600C, Force4625
Affected versions: 5.7.0 and newer

Starting 5.7 firmware release Automated Frequency Coordination (AFC) functionality has been introduced for ePMP 6GHz ePMP4600x/Force46xx platforms.

AFC establishes the regulations for the unlicensed use of the 6 GHz band (5.925-7.125 GHz), aimed at mitigating potential interference from conventional high-power access devices and stationary client devices to licensed microwave receivers and specific radio astronomy observatories operating within this frequency range.

Definition of different modes:

Standard Power AP: This is when the device operates as an access point or backhaul master and requires the device to send geo-location information. In this mode, the device is allowed to operate at a maximum of up to 36dBm EIRP.

Standard Client: This is when a device is operating as a SM or backhaul client and does not require geo-location information to be shared with the AFC. In this mode, the device is allowed to operate at 6dB lower than the AP it communicates with. The AP will continue to operate in standard power mode and receive its channel allocation from the AFC.

Fixed Client: The device is operating as a SM or backhaul client and communicating to the AFC using geo-location information derived from a GPS source. The device is allowed to operate at the same EIRP level as the AP it communicates with. Maximum EIRP allowed is up to 36dBm.

6GHz Operation Rules:

• Requires the use of AFC;
• UNII-5 and UNII-7 will be allowed for fixed outdoor use at 36 dBm EIRP in the United States;
• In addition, Canada allows UNII-6;
• All SMs and APs require specific GPS receiver from the manufacturer to indicate location, except SMs operating in Standard Client Mode;

The AFC purpose and rules:
• Goal is to prioritize and protect incumbent 6 GHz licensed microwave networks;
• 6 GHz unlicensed networks can only use channels that are not previously assigned to licensed microwave;
• Can use any channel not protected by the AFC;
• There is no prioritization or channel assignment;

How Does AFC work?

*In standard power AP mode, which all three SKUs (4600, Force600 & 4625) support require GPS to send geo-location information. For the 4600 & Force600C this is built in while the 4625 has an optional USB based GPS puck. Only during fixed client operation is the GPS puck required for the SM. If operating in standard client mode, the GPS puck is not necessary.

• Each radio must separately query the AFC with its precise location and pre-shared encryption key;
• all transactions use HTTPS Queries happen once at startup and then every 24 hours or after each configuration change;
• Queries are not latency sensitive and require negligible throughput;
• APs configured to Fixed Client Mode will not transmit unless in compliance with AFC response;

What are the requirements to connect to the AFC system?
In order to use the Automated Frequency Coordination (AFC) system, the Access Points and Subscriber Modules operating in Standard Power and Fixed Client Mode must:

1. Be able to make HTTPS requests out to the Internet.
2. Be running firmware version 5.7 or greater.
3. Have DNS server configured.
4. Get geo-location data in a real time from GPS receiver
5. FCC locked SKUs

The units are pre-provisioned with AFC keys at the factory in order to authenticate. Release 5.7 supports connectivity to the AFC and user interface information showcasing channel availability.

The AFC Server connection Status is displayed on the AFC section on Configuration → Radio page along with the operational channel information.

Radio Configuration section is extended with the data obtained from the AFC server in the chart format that simplifies the process of the best operational channel selection for the FCC APs.

The chart demonstrates available channels and Tx power allowed accordingly. The chart scale can be changed for accurate data analysis using the lower chart.

[Chart is clickable, and channel can be configured directly from the chart].
Spectrum Analyzer chart can be enabled on Configuration → Radio page below AFC chart to give more data for the best channel selection.

On the SM side two operational modes are allowed:

• Standard Client Mode (Default)
• Fixed Client Mode

cnMaestro Template for Fixed Client mode configuration:

{ 
	"wireless": 
	{ 
		"@wifi-iface[0]": 
		{	 
			"afc_sta_mode":	"1" 
		}	 
	} 
} 

AFC related SNMP traps available on the system:

cambiumAfcEventWaitTrap - .1.3.6.1.4.1.17713.21.0.17 
cambiumAfcTxOffTrap - .1.3.6.1.4.1.17713.21.0.18 
cambiumAfcExpiryTrap - .1.3.6.1.4.1.17713.21.0.19 
cambiumAfcEventOperatingTrap - .1.3.6.1.4.1.17713.21.0.20 

[DigitalMan2020]

@Fedor what is the difference between Standard Client Mode (Default) and Fixed Client Mode?

[Fedor]

Thank you for a good question.
I edited the article and put these information on top.
I will continue to populate the article as questions come in.

Thanks.

[GREG3f]

Will the CPE attempt to contact the AFC while set to Standard Default Mode or does it only attempt in Fixed Client Mode?
Will the CPE make an initial connection in Fixed Client Mode even if it has never reached the AFC?
Is there a specific URL or IP address that we can ping to confirm we have adequate access tot the AFC?

[cbl]

Looks like Qualcomm is the defacto Cambium choice for AFC.

When will we have the option to pick our preferred AFC service provider?

[aka (Andrii)]

Hello @cbl and @GREG3f !

There can be other AFC providers in future. But as for now Cambium will work with Qualcomm only.
Unfortunately, Qualcomm server does not allow ICMP. It is deployed in cloud. So has to be very reliable. As for now, we have no user friendly methods other then test radio’s Internet access in general. Our engineers also can test it trying https request from root CLI.

Also, please, check our new FAQ regarding AFC deployments!