Switching to 3G only

[Richmond]

I have discovered that switching to '3G only' gives me a much better
signal. I think I knew this some time in the past and forgot about it,
but it occured to me just now when I was looking at an old Nokia on O2
and it was showing 4/4 signal, whereas my fancy new smart phone shows
1/4. But is it worth setting it to 3G only? shouldn't it switch to 3G
automatically if it has a weak signal? I've noticed the signal can go up
when making a call on 4G but I am not sure what happens on incoming
calls. Bard tells me the network operator might prefer me to use a weak
4G than a stronger 3G.

[notya...@gmail.com]

The channel used for connection is strong all the time and all phones listen to it. Once connected the phone and the base station negotiate the power levels in both directions to reduce adjacent and co-channel interference.

[Woody]

Erm, may not be quite correct. To change base Tx power per time slot
would be very difficult to do at the required speed. I think you will
find that the base Tx power is constant - typically 2W per channel on
GSM - and it is the mobile that changes its power. Said power
negotiation takes place during the initial call setup - the mobile
usually waves its flag for attention at full power to make sure it can
get in, and then negotiates down to -20dB in 2dB steps. If the base Tx
switches you to the wrong antenna the call will usually fail - a very
common occurrence. Power adjustment is more designed to save battery
power than to reduce CCI.

[Richmond]

Using the app Network Cell Info Lite I can see if I switch on 4G and
look at the map the signal is coming from cell tower to the north of
me. The signal is poor, -118. If I switch to 2G and look at the map, the
signal is coming from a tower to the south of me. The signal is good,
above -90.

For me 2G is a technological revolution. I no longer need to worry about
where I have left my phone, I no longer need to leave it balanced on the
back of a chair pointing out the window to make sure I get calls. 2G is
the future!

[notya...@gmail.com]

Thanks for the correction - might have been true in TACS / ETACS but not as you point out 2G. The negotiation was greater for car phones (up to 6W) than hand held (0.6W or 1W depending on generation)

[Woody]

Not sure what you mean in the first sentence Mark.
In terms of handhelds, most have a Tx power of 400mW which can be
reduced as necessary as it moves around in 2dB steps down to as low as 4mW.
Agreed, mobiles were a very different kettle of fish!

[notya...@gmail.com]

Well the weren't stunningly efficient, my Technophone Mk1 used to heat up on a long call and eventually split the case over the heat sink. 0.6W, probably its total power.

Will maybe try and dig out my ETACS specification sometime.