  Quantitative characterization of randomly roving agents in wireless sensor
networks (WSN) is studied. Below the formula simplifications, regarding the
known results and publications, it is shown that the basic agent model is
probabilistically equivalent to a similar simpler model and then a formula for
frequencies is achieved in terms of combinatorial second kind Stirling numbers.
Stirling numbers are well studied and different estimates are known for them
letting to justify the roving agents quantitative characteristics.
