IBU

Consol

Mobile Phone Range In Australia

Corrections Welcome

Someone travelling the largely un-populated West Australian coast hundreds of kilometres north of Perth wrote in Oct. 2002, Re. their Nokia 3310 mobile phone, & using it for email:

• It's a big empty country ! Mobile phone signals dont propagate that far, & need more transmitter masts than are installed, I guess. (There were dead spots even in highly populated Germany in 2001)
• Some Range Limitations Are:
  • Which Phone Company
  • GSM Signal Slot Timing
  • Signal Strength
  • Modem Speed
  • Frequencies

Which Phone Company

• Not all net suppliers are willing to share the same masts - (EG they don't in the UK, where there's 2 rival groupings, & only one group's signal is receivable at RS's place). Competing masts may be in different places, so you may observe different reception signal strengths in the same place, from different companies.
• Mobile phones can be set to either use a specific network, or automatically use what seems `best'. When on automatic, `Best' probably first means use same company as SIM card, even if the signal is weaker (& thus `Best' might give a worse data connection ?). On manual select, if the SIM card in phone is not from the network you select, the company might not grant service, or may charge more. The network operator you select in town may not be so good for longer distance out of town (EG Germany used to have better national coverage from Deutsche Telecom, but better coverage or more atractive terms in major cities from other suppliers.
• For a Nokia 6110: Use Menu 4= Settings, 4-4= Phone Settings, 4-4-5= Network Selection. Automatic Lets the phone decide. Manual does an immediate scan to see what radio reception of network suppliers is possible, then you can select any supplier detected.

GSM Signal Slot Timing

• Expect possibly 20 to 40 Kilometres from the nearest mast, & not much more ! - Regardless which GSM phone model or manufacturer you use. (Ask FC for correct number & explanation).
• I think all modern world type phones are GSM (digital) & a constraint is the width of time slot allowed by the GSM standard while scanning for phones, for the signal to travel from the mast to your phone, & back to mast, before it's time to talk to move on & negotiate with next phone customer. Maximum distance is limited by speed of radio transmissions (which is roughly speed of light), that's high, but not infinite. The slot time is very short, so you'r limited.
• G.E. found on the Atlantic off Portugal, his phone could `see' the base station (=signal from mast) at 50 KM from land, but couldn't interact with it until 20 KM from land. (he was on a small [4?] man boat, & may have also been limited by signal strength, & perhaps deep between waves at times perhaps ? so maybe on flat waterrange might be further ?
• Australia has a double time slot, [so you might get approx twice that distance ?] F.C. says:
  The timing advance is 5 bits or 32 values in units of one quarter bit. 1 QB is 4.59183/5000 ms, and if you work it out you will find max advance is about 30km. Australia allows for 200 km cells, but this is transparent to the mobile. The base station is special
• Presumably old fashioned analogue phones do not suffer this constraint, but then they may be hard to obtain, & network access may not be available too, & those phones will suffer normal radio signal degradation dependent on distances, but with shorter range than radio, as higher frequency. It's worth asking knowledgeable locals who live/work in the sticks & need mobile range. - Maybe that's why many are keen on CB, powered by vehicle battery & antenna ?

Signal Strength - & Obstacles

• You can get an external vehicle aerial that plugs into some phones, & leads out to an aerial on the car body. The Nokia 6110 has a rubber bung on the back, under the aerial, pull it off & there's a socket for an external aerial.
• The signal strength is shown on the front left column of a Nokia 6110 (but I think it's possible to turn it off, if it has been, turn it on again :-)
• In cities part of the reason for so many masts is that the buildings shield the signal. Mountains too.
• The signal doesnt bend round hills either, 2 month back walking in Bavaria the signal completely died in one short deep valley.
• A flat conductive surface EG calm lake, (even a sea/estuary), between mobile phone & phone company mast, generally helps radio transmission. (I guess flat snowfields in EG Arctic/Antarctica would do too, wet salt plains might be particularly good.
• Any signal strength versus distance measuring experiments should be done on flat landscapes approaching or leaving small isolated towns, with masts in the town but no further masts outside.
• Probably you will see decreased signal strength on the LCD display, long before you hear a difference, as GSM phones are digital, & audio will probably only fail when the signal is really bad,
• A metal vehicle EG car or caravan, is known as a Faraday Cage to radio engineers, & reduces signal strength considerably. You'll get better signal reception strength in open air or 2nd best, in a canvas tent, not in a car or caravan. BTW If you sit in car or caravan when using the phone, as the signal received at the mast is lower, the mast signals the phone to increase it's transmission signal strength. So you get more more microwave energy into your brain than you would if you got out of the car /caravan to use the phone.
• Draw a line from phone aerial to mast (centre of town I guess) does it go through your head ? If so you'r making it hard work for phone (& head !) most people hold phone consistently one side of head (habit, or they prefer that side microwave cooked most ;-) & if that is in middle of car, rather than near a window facing a transmitter mast, that make is more problematic. Presumably in Australia the window facing the transmitter is the laminated (screening ?) windscreen on the distant tail gate, tunneled by the length of the car. LI>Get out of vehicle for a better signal. But move well away from vehicle at fuel stops, it's even illegal to use a mobile phone near a fuel pump in Germany, for fear of radio transmitter inciting an explosion.
• A window wound down, if adjacent to phone & in line of sight to transmitter may help ? I know glass zaps an 11 GHz Astra satellite TV signal, (dirty glass especially I recall).
• Is any person, head, hand etc, metal or (particulalrly reinforced) concrete, stone, or laptop screen or other object between the mobile phone & the mast in the town ? All objects will reduce signal strength more than empty air. Try holding phone verticaly, around just the lower part of the phone, to avoid your hand screening the antenna/aerial which is usually in the top half of phones). While looking at signal strength on LCD screen, hold phone above head, & or clear of other cars/obstructions. You can do this while not connected & not paying money for calls, so it's easy to experiment, looking at signal strength).
• When used with a laptop for data, is the phone mounted vertically ? probably not, but it probably would help if it was ! It's probably laying down because it's got a cable stuck in the base, & your hands are on the computer, but think about it: As the phone companies' masts are vertical, the max. signal strength will probably be when the phone is parallel IE also vertical, as it would be when yoyu were standing or siting, talking on the phone. Try to get it vertical. Perhaps use an open mesh cotton/material thread bag that fruit sells in, & suspend the mobile phone vertically in it, & hang it on a nail or washing line/ string to a tree, allowing cable to hang down through bag.
• In other (non Australian!) climates, I suspect heavy rain/fog will reduce signal strength too (it kills analogue Astra satellite TV).

Modem Speed

• Data links for Internet will probably fail before audio becomes unusable.
• Higher modem speeds need good quality phone `lines'.
• Try to tell your computer to be less ambitious about negotiating top speed data rate .
• Computers initialises `modems' with a Hayes compatible configuration sequence beginning "AT".
• Although your Nokia has a `soft modem', it may still may be possible to tell your software to be less ambitious, & to try first for a slower data transfer rate.

Frequencies - Practical

• Dual band GSM mobile phones are 800 MHz & 900 MHz.
• USA uses 1800 MHz (=1.8 GHz) & may have longer range ?

Frequencies - Theory/ Speculative

 From:      "Jens G. Balchen" <balchen_ERASE@saint-etienne.no> 
Date:       Mon, 07 Jun 2004 15:45:25 +1000 

Hi.

I just wanted to make a short comment on mobile phone frequencies and
their effect on signal range. The higher the frequency, the shorter the
range. Traditional radio signals operate on a very low frequency, and can
theoretically reach the other side of the world if the atmospheric
conditions are favourable. On the other hand, low frequency signals don't
reflect as well from surfaces, so you need line of sight.

In the Nordic countries and Central Europe, a mobile system called NMT was
in popular use during the 80's. It was an analog system, and originally
operated at 450 MHz. When GSM was introduced at 900 MHz, a lot more base
stations were needed to cover the same geographical area.

Your Astra satelite signal at 11 MHz is disturbed by the glass window for
exactly this reason. High-frequency signals tend to bounce off surfaces,
especially hard ones such as concrete, steel and glass. Bluetooth radio
signals and IEEE 802.11 operate at 2.4 GHz, and cannot penetrate any hard
surface (also due to their weak signal, of course) -- however, because of
its tendency to reflect off surfaces, it can normally circumvent obstacles
(e.g. I can use my Bluetooth headset several meters down the office
corridor with my phone in the office, so long as the door is open).

This feature of high-frequency signals is the reason you need a lot of
base station inside cities with high-rise buildings. The buildings make
the signals bounce off the outskirts of the city and reflect back to the
mast (or contain your mobile phone's signal inside the city). Signals may
still get out, but they will have bounced from building to building, and
the quality will be terrible.

I once tried out wireless broadband from a provider located only 1 km
away. The two point-to-point antennas were facing each other, but line of
sight was interrupted by a building one story taller than mine and the
provider's. The strength of the signal was fairly poor (1 out of 3 LED
indicators on the receiver), but in foggy conditions the strength
increased dramatically. I contributed this to the increased reflection in
the atmosphere (from the tiny drops of water) -- the signal was able to
bounce over the obstacle and then down again without significant loss of
quality.

To conclude: GSM 1800 does not provide greater range than GSM 900, but it
provides greater reflection. Since most mobile users live in cities, this
is more beneficial than range.