4G Won't Affect Short-Range Devices

Concerns that the introduction of 4G will affect short-range devices, such as hearing aids and alarm clocks, have been allayed in a new study by Ofcom which found LTE handsets won’t be powerful enough to produce enough interference.

The auction for the 4G spectrum is to begin later on this year, although it’s unlikely that we will see any 4G services until late next year. The concern over interference has come about due to one of the "uplink bands” being close to the spectrum reserved for short range devices.

These include wireless microphones, alarms and hearing aids, which has raised the question of whether the new fourth generation bandwidth will knock such services out as the 4G spectrum ‘bleeds’ into the short-range spectrum in a leakage known as 'out of band' (OOB).

Ofcom’s report shows that "the device manufacturers have done sterling work squaring the signal for LTE,” according to The Register. The report shows that mobile devices operating in the middle of the 800MHz band showed no real evidence to suggest that there will be any significant leakage into the short-range band.

"Our high level conclusion regards LTE UE emission is that the level and likelihood of emissions falling at a particular frequency in the adjacent band is related to the uplink resource demand from the user; the scheduling algorithms of the LTE network; and the transmit power level of the UE,” the telecoms regulator said in its report.

"This is in line with what we have said in our previous studies [] when suggesting that we believe that the likelihood of those worst case scenarios occurring is low.”

This is part due to the fact that mobile handsets don’t transmit at full power all the time, in fact, very little of the time due to battery saving features which automatically kick-in if you’re not using the phone. This further reduces the risk of interference with the lower-frequency spectrum and supports Ofcom’s theory that interference should be little to none.