Originally Posted by
Globaliser
That's exactly it. With a picocell on board, the handset will only transmit at its minimum power, thus minimising the possibility of RF interference. It's therefore restricted to a tiny fraction of full power.
If the picocell is not there, then the handsets tend to pump out at full whack, which can be about 2W IIRC.
Not at all true. The handset MAY transmit at its minimum power BUT only once established on the onboard PICO Cell. But it may also transmit at its full power If:
- The onboard Pico cell fails
- The onboard Pico cell is unable to offer a connection to a handset because it's full bandwidth is occupied by other handsets
- The underlying network refuses access to the handset (say because the customer is pay-as-go and not allowed to roam)
- The customer has the "manual network" search option selected which forces the handset to do a full power search for all nearby cellsites.
- Data enabled devices such as the blackberry don't transmit on GSM, they use 2.5G or GPRS which by default uses a higher transmission power to increase reliability and decrease data corruption.
- Finally, the uplink from the pico will be provided by a sat network, countless factors can affect the performance of this link too and if it fails or degrades handsets will increase their power automatically to search for an alternative cellsite.
Any and all of the above occur in ground based situations every hour of the day, so they will happen in the air too, and when 200 handsets start transmitting noise at full power the first people to hear it will be the boys on the FD, then the CC will hear it using the interphone, the pax will hear it over the PA and that’s before we start discussing the unproven allegations that they will also interfere with other, more critical aircraft systems.
FLR