PACE' is an acronym and methodology used to build a communication plan. PACE stands for Primary, Alternate, Contingency, and Emergency means of communication. The method requires the author to determine the different parties that need to communicate and then determine, if possible, the best four forms of communication between each of those parties. PACE also designates the order in which an element will move through available communications systems until contact can be established with the desired distant element(s). Ideally each method will be completely separate and independent of the other method of communication. For each method, the receiver must sense which one the sender is using.
A PACE-based Communication Plan exists for a specific mission or task, not a specific unit, because the plan must consider both intra- and inter-unit sharing of information.
Primary = the primary and intended method of communication between parties.
Alternate = another common method of accomplishing the task with minimal to no other impact. Often used co-currently with primary.
Contingency = method will not be as fast/easy/inexpensive/convenient as the first two methods but is capable of accomplishing the task in an acceptable time frame.
Emergency = method of last resort and typically has significant delays, costs, and/or impacts. Often but undesirably the receiver rarely monitors this method.
A few examples.