The main interest in ICS for a scanner listener is what exactly do you want to listen to at a large incident like this major fire diagramed above.

Some scanner listeners don't want to hear portions of the incident. The way ICS can organize communication, you can almost bet on certain aspects of the incident being on seperate radio channels. In that case, you pick what you want to listen to, and you don't have to hear anything else.

On the other hand, some like to hear everything they possibly can. In this case, the ICS will organize what you are listening to, and make the scanning job easier.

Command traffic is the highest level of traffic at an incident. Administrative and command decisions are made at this level. Actual radio traffic isn't as busy as a tactical frequency, you will certainly hear lots of good behind the scenes radio traffic here. On the diagram, you'll notice the Command Team is using a radio channel called Command 7 (a CDF repeater). All the command staff can talk with each other, as well as expanded dispatch on this frequency.

In the Operations Section, there is a lot of radio traffic to coordinate tactical maneuvers on the incident. Each Division, Group and Branch has a supervisor that can communicate with the Operations Section Chf on a command frequency, sometimes seperate then the Command Team's frequency. This is another hot frequency to listen to on a major fire incident.

Tactical traffic is for localized units who need to coordinate how they are doing things. Therefore, seperate groups, divisions etc. in the Operations Section usually get their own frequencies. Each supervisor can monitor their local traffic, as well as the command traffic to their section chief.

In the Logistics section, you can monitor any medical needs on an incident on a separate frequency, in this case Calcord 156.075 for California. Supply sometimes uses a satellite uplink to the command center to transfer large amounts of supply lists and needs. OASIS is California's OES satellite system. Before a sat trailer can get there however, sometimes Amateur Radio (VIP in California) can handle the supply needs. They can either move lengthy lists off of busy fire channels over the amateur frequencies, or use digital modes such as packet radio to transfer lists of needs.

Facilities such as Incident Bases and Camps need their own in-camp communications to organize how everything is going. Sometimes they'll be on a separate frequency, or even FRS radio at times.

Amateur Radio, used in CDF's Volunteers in Prevention (VIP) can also be utilized for passing fire info and other information needs between Expanded Dispatch, Command Team's public information officer, and the Situation Unit in the Planning section. All this non-critical traffic can be passed over amateur radio frequencies to free up fire frequencies for the incident needs.