the magnitude of a medical problem to their fire officer at the command post. This request would add to their commander's operational picture of the division or incident command as she called EMS to request the ambulances. Situation awareness is an important part of effective command and is easy to lose at a large incident. Bypassing incident commanders can contribute to a decomposing of command. Trunked systems, commercial services, and cross-department netting One approach to cross-department netting is the capability of some modern trunked systems to provide a function called dynamic regrouping; a feature that Motorola doesn't support in simplex (e.g. 'fireground') operations. It is therefore necessary for a disaster to be near enough the infrastructure to allow for repeater access/operation. Many agencies with Motorola trunked systems already have this capability but it's hardly ever used; even in a crisis. The difficulty of operating such a system is often too great for poorly educated dispatchers who often have no college – much less any particular training in computers or communications systems – other than the 'cursory' training they receive in a 3 or 5 day class the vendors offer. The feature allows the dispatch center personnel to send units from different agencies who are responding to the same incident to a common talk group or virtual channel. This assumes the agencies all share a capability to operate over the same trunked radio system, which is rare. In an informal survey of three agencies with trunked systems that included this feature, users at two sites reported they did not think their system included the feature. A representative from a third site said he "...thought they had the feature but never used it." Of the three agencies with the feature, no one knew how to use it. This would suggest, (in at least the three agencies contacted,) that dynamic regrouping was not valuable. Like other disaster readiness processes, users would have to practice using the feature in order for it to be useful during an incident. Some agencies use commercial two-way radio as an adjunct to their own communications networks. One professional engineering evaluation of public safety radio systems explains that commercial systems such as Nextel's are not built to the same standards of coverage and non-blocking as public safety trunked systems. Like toy walkie talkies marketed to children, they are usable and helpful for non-urgent communications but should not be considered