https://docs.google.com/viewer?a=v&pid=explorer&chrome=true&srcid=1m3ML6K5LThSQgfzWfrCo-E6OnWlPuMemtauKfkjTfoqolV25zCy81gQvgO_z&hl=en - 2006 overview of public safety radio and communications systems - with freqs and PLs