New (?) finding - Phone Band settings affect download speed

[hardcore]

I am currently heavily using data connections over an EDGE network, and noticed something interesting.

When I set the phone band settings to Band = "Auto", I get much slower download speeds. I used the fieldtest utility to check the GPRS/E-GPRS stats, and can see that the phone was only allocating 1R1T, or 1 receive slot + 1 transmit slot! (limiting the speed to about 60kbit/sec for EDGE).

I remember I used to get better speeds, so I tried changing the band settings to Band = "GSM900/1800 + UMTS2100" which is what my network is on.

Now the download speeds were fast again! Back to the fieldtest utility and saw that the phone was now allocating 4R1T (4 receive slots + 1 transmit slot), giving me about 200kbit/sec downloads.

I wouldnt have guessed that the band settings would affect the GPRS/EDGE timeslot class usage. Note that this testing was done using radio 1.40.30.00, and WM6 LVSW 19-5 / Elf 2.1.

Found that the Band settings cause the change. The Mode (Auto/GSM/WCDMA) setting does not affect it.

UPDATE: This seems to affect only certain radio roms. On others, it has no affect (those roms can allocate 4R1T on Auto band).

Tested using EDGE on a GSM1800 network. Most likely in a 3G or HSDPA network there will be little to no affect.

Radio ROMs which are affected:
1.40.30.00, 1.38.30.00

Radio ROMs which are NOT affected (no difference):
1.41.00.10, 1.38.00.01, 1.38.00.10

If you are trying this out, please include the slot combination you got (with an active download), your radio rom version, OS version, network type (GPRS/EDGE/3G), and band (GSM850,900,1800,1900) if you know them. May try to compile some statistics and update this post.

(so far, its looking like this behaviour is limited to only the 1.xx.30.xx radio roms)

 

[fmg9800]

Switching settings

I sense everyone is currently changing their settings. I tried it and whether it was the placebo effect or not - sure did seem to be faster.

Mark

 

[harlenm]

Settings on Auto, using 200K test from dslreports/mspeed, Edge = 158kbit/sec.

Settings on GSM using same test 170Kbit/sec.

That's pretty close.

BTW, I'm using LVSW 5/19 with the 1.41 radio.

 

[hardcore]

Settings on Auto, using 200K test from dslreports/mspeed, Edge = 158kbit/sec.

Settings on GSM using same test 170Kbit/sec.

That's pretty close.

BTW, I'm using LVSW 5/19 with the 1.41 radio.

Did some more testing. The GSM/WCDMA setting does not affect the speed, its the Band settings that does. Try changing those and see if it makes any difference for you?

No need for "placebo" effects. If you have the fieldtest utility installed, you can use it to check the timeslot allocation - go to the GPRS/E-GPRS page, check the last parameter called "Slot Combination". It should say something like "5: 4R1T" (4 receive, 1 transmit) or "2: 1R1T" (1 receive, 1 transmit).

 

[si200]

Hi, i was wondering how i would change the setting and if i would need any software to do it

Thanx in advance...

 

[unwired4]

Its in phone menu, options, BAND tab.


I just tried it out of interest and ran a speed test and got 758kb/s over HSDPA with it on GSM900/1800 + UMTS2100 and 659 kb/s on Auto.

 

[m15chief]

Using 1MB test on www.dslreports.com/mspeed

Auto = 148 kbit/sec

GSM(900 + 1800)+UMTS(2100) = 762 kbit/sec

Using Sleuths LVSW variant, radio 1.41

Both from exactly the same place on my desk at work

 

[todd_jg]

Well, I just tested. The result I got was slightly different. I got the 4R1T allocation with all auto settings. Interestingly, I did have a 1R1T allocation when I just checked from idle. When I loaded up some pages in the browser (to sort of "prime" the data connection) and then checked, I had the 4R1T allocation. All with the settings in auto mode. Just my experience.

 

[ccezar2004]

i do not have more than 350Kb/sec... even though ot shows that i have a HSDPA connection... and the band set to manually....

 

[hardcore]

Today I just changed my radio rom to 1.41.00.10 and tested the settings again. This time, there was a different behaviour. Neither the band or mode settings had an effect on the slot combination. In both cases, slot combination was always able to get to 4R1T. Again, this is on an EDGE network.

It seems the slot combination being limited to 1R1T on Auto band selection only affected certain radio ROMs - affected radios 1.38.30.10 and 1.40.30.10 for me (on EDGE). Seems to me like a "bug" on those radio versions. I might try 1.38.00.10 and 1.38.00.01 later.

 

[hardcore]

Well, I just tested. The result I got was slightly different. I got the 4R1T allocation with all auto settings. Interestingly, I did have a 1R1T allocation when I just checked from idle. When I loaded up some pages in the browser (to sort of "prime" the data connection) and then checked, I had the 4R1T allocation. All with the settings in auto mode. Just my experience.

Had similar experiences, although for me on radio rom 1.40.30, the slot allocation seemed to be stuck at 1R1T and didn't go to 4R1T unless I had the band manually selected. It could be different roms "ramp up" the slot allocation differently.

I imagine that the battery consumption with 1R1T could be a lot lower than 4R1T though. However, I found 4R1T connections to be more stable as well - sometimes on a 1R1T allocation, the internet connection would hang up a lot more - could just be bandwidth starvation.

 

[Sleuth255]

Nice find!

Moved to hermes forum for more exposure.

 

[kipe]

Today I just changed my radio rom to 1.41.00.10 and tested the settings again. This time, there was a different behaviour. Neither the band or mode settings had an effect on the slot combination. In both cases, slot combination was always able to get to 4R1T. Again, this is on an EDGE network.

yes, hardcore affiirmative on my side too with regard to 1.41 & changing of band settings from auto to UMTS 21000 ..not much different (slightly faster when not on auto mode) between both combo.. running the internet sharing when getting the results below (running 1.41 Radio with LVSW 3.30.2.1 ROM)




Test done with network set to Auto band set to UMTS GSM 900+1800 UMTS 2100



network=auto band=auto



network=wcdma band=UMTS GSM 900+1800 UMTS 2100

 

[hardcore]

Update: I tested a few recent radio roms.

This seems to only have an affect on:
- Radio ROMS 1.38.30.00 and 1.40.30.00
- EDGE/GPRS connections (not sure about 3G/HSDPA)

On radio roms 1.38.00.01, 1.38.00.10, 1.41.00.10, the settings had no effect.

 

[luiggi]

Is this the way it supouse to work?

Did some more testing. The GSM/WCDMA setting does not affect the speed, its the Band settings that does. Try changing those and see if it makes any difference for you?

No need for "placebo" effects. If you have the fieldtest utility installed, you can use it to check the timeslot allocation - go to the GPRS/E-GPRS page, check the last parameter called "Slot Combination". It should say something like "5: 4R1T" (4 receive, 1 transmit) or "2: 1R1T" (1 receive, 1 transmit).

When I start "browsing" IE the phone is able to get 4R1T, after few seconds (and while IE still displays "Opening") the Slot Combination data turns to "255".
BTW, I´m trying to determine why my data connection is so bad.... any help is appreciated.