Hi,
This is for the initial startup of a cell and for a
situation of a sudden influx of a
huge number of phones. In a normal situation you should not have RACH
channel saturated and thus this mechanism is not triggered,
It is a very common situation that for example a train with a few hundred phones
enters the tunnel area what is connected to a different location area, and all those
phones want to perform a location update. Happens not far from my home every
few minutes, for almost 20 hours per day, for about ten years now :)
Btw., OpenBTS seems to handle this quite well, I had the situation of about 60 phone
jumping onto my poor little USRP1/WBX cell, and I mean to remember that even the
console output showed the queue handling. So I am not sure if such a measure like
reducing the power would be useful at all in whatever scenario. Commercial systems
that I monitored after breakdowns or maintenance shutdowns just came back again
with full power, it all sorted out itself within short time. Among them were cells near
airports or heavily crowded roads and pedestrian areas. I wonder if we see a problem
where in fact there isn't one at all.
--
Regards,
Alexander Chemeris.
CEO, Fairwaves LLC / ООО УмРадио
http://fairwaves.ru
Ralph.