[apparently this didn't 'stick' the first time]

Some people debate whether 'intellectual property' (such as patents) should exist.  The standard for patenting is said to be:  An invention, to be patentable, should be "new, useful, and unobvious to those skilled in the art".  A month ago, when it became obvious that finding Air Malaysia Flight 370 could be difficult, the 30-day limit of the electronic pingers got me to thinking.  Why?  Instead of pinging for 30 days, why not have them ping increasingly slowly, so that the pinger would last 'forever'.  Considered discretely, let it ping at the normal rate for 1 week, at half the rate for the next week, at quarter the rate for the subsequent rate, etc.   Or, have a continuous equivalent of this, a ping-rate which slows to approximate this rate over time.  This kind of pinger would 'never' run out.
   Should this idea be patentable?  Is it new?  I haven't heard of it.   Is it useful?  It is now clear why it would be useful...now!!!   Is it 'un-obvious'?  Well, despite the fact that I just thought of it a month ago, and I had never heard it proposed before, I wonder why it shouldn't be called 'obvious'.  If anything, I think it's amazing that it hasn't been implemented before.  People who work in aeronautics and electronics are smart and imaginative...at least I thought they were...until now?
It should also be possible to include in the ping, information  (transmitted by pulse-position information) about the last lat/lon received by the aircraft.  
        Jim Bell