You can slave a commlink to your cyberdeck.
The commlink is a device.
The cyberdeck is a device.
A device can be part of your PAN.
Your commlink may use your cyberdeck's matrix attributs when defending (if they are higher).
You can base your persona on your commlink
Your persona based on your commlink will use matrix attributes of your commlink.
Your persona based on your commlink cannot be slaved to the cyberdeck.
A persona cannot be part of your PAN.
Your persona based on your commlink may NOT use your cyberdeck's matrix attributes when defending.
If that's true:
A rigger slaves his drones to a RCC
A rigger goes online forming a persona on the RCC which replaces the RCC device in the matrix
A persona cannot be part of a PAN
The drones are not slaved anymore and he can't use the features of the RCC.
Makes sense... 
And a decker loses his ability to help his team with matrix security by slaving their commlinks the moment he goes online... 
If you don't include 'personas based on a device' to the things that can be part of a PAN or WAN the whole setting and rules make absolutely no sense. 
More like Rigger slaves his drones to his RCC making RCC the master device and creates a special rigger style PAN where the RCC manages several parallel connections at once, so you can give a command to one, all, of the slave drones with the same Simple Action and this parallel multi-connection also lets you jump from one slaved drone to another without first jumping out of the drone you’re leaving or rebooting the device because your persona was removed from it. The special RCC PAN also allows a slaved device to use either its own or its master’s Rating for each Rating in the test but if you get a mark on the device you also get a mark on the RCC
Now when it comes to security spider riggers they dont use PANs but WANs
with multiple devices slaved to a host. This is the world of
that special kind of rigger, the security spider.
They slave
their RCC to the building’s host and connect to the entire
security system, including all of its slaved drones.
When
you’re inside a host, your effective “physical distance” to
drones slaved to that host becomes zero, even if you’re
on the other side of the world. The spider-rigger is often
teamed up with a spider-decker to help against hacking
intrusions on the security system.
So you can Slave a RCC to a host provided you are a security rigger spider
my understanding is the persona is the "Soul" of a entity in the matrix the device (which can be one of four things, a commlink a cyberdeck a RCC or a device that has been modified to accept a persona firmware) and is the physical representation of said persona in the meat world
icons are a matrix representation of devices in the matrix with no persona attached to it
So with that in mind I supposed you can only slave devices to a deckers cyberdeck for defense and either turn your commlink wifi off or turn it off completely or get a throw away so you dont stand out too much in public as someone without a persona and a back up when your decker isnt running matrix defense for you (course considering it all wireless you and your decker dont have to be close in even in the same continent for the decker to defend your devices running wireless which provides and interesting opportunity to have these deckers hire out their services to run matrix protection against other cyber attacks