GSM Handset Range from Tower ???

[ol' boy]

Hey all, I’m trying to understand how my 3 year old beat up Sony Erricson W800i GSM Digital handset can connect to a Tower near on 60Km away. Not only is the Signal Full strength, but there is also no lagging or dropping in voice packets. It is in direct line of site and both locations are elevated on a hill above the ground in between.

From my reading, I understand Digital GSM network in Australia uses the TDMA or Time Slots.

Using Full Rate (FR) this gives you 64 Time Advances. One Time Advance is 550meters from the Tower to the Handset. Thus 64 x 550m = 35.2Km. The often spoken about limit or range at which a GSM handset can still communicate with the Tower.

Now using Half Rate (HR) gives you 128 Time Advances, thus a theoretical range of 70Km.

Notes taken from here: (although this document is now 9 years old)

In my situation I am 60km line of sight from the tower.
Up until 2 years ago, signal at this location was marginal and flakey using the same handset and it was coming from the same tower.
Some time in the recent 2 years the signal increased to Full and Phone Calls can be made anytime and including from inside your car etc. Still from the same tower, still using the ever aging old Sony handset.

Does this mean when using HR or EFR we can get expect longer than the standard quoted 35km using 2.5G handsets?

BTW, this is the Tower in question:

All tests have been done using the Vodafone network

Thanks

[tytower]

The quotes and references are beyond me some but generally transmission at that frequency is line of sight . Normally 20 miles due to the curve of the earth . That frequency will not bounce off the ionisphere and a ground wave seems to fade fast.

So jump for joy , thats why they site them as high as they can and you are lucky to have a high reception point .

It may be that the antenna at the tower was moved in your favour recently or a new buildings steel reflects it in your direction.
Generally in the country Vodaphone have the weakest signal eg. I just get Telstra at home but have to drive 12 K to get Optus and vodaphone.
Thats in the country .

Bloody Telstra , they should be shot for the lies they tell and the monies they steal

[ol' boy]

Thanks ty, but i seem to think it may have to do with the timing of the TDMA and possible signal strength.
Are you sure UHF only goes 20miles due to the curve of the earth?