UMTS & HSDPA Hopping

[ATrueJesusFreak]

Hey, I have an USA T-Mobile Vibrant.

It is rooted and running the Vibrant edition of Darky's 9.3 Final ROM.

I am also using the latest overstock kernal and the honeycomb 2.0 theme from the I9000 forums.

Enough background info. This isn't really a problem as much as my curiosity.

My phone almost constantly is switching back and forth between 3G (UMTS) and H (HSDPA) on my data connection.

It doesn't seem to affect battery life or service too much (though H might be faster), so I'm not worried; but does anyone know what the deal is with this?

Thanks ahead of time!!!


Sent from my Vibrant using XDA App

 

[CrazyCharlie]

Mine has been doing this lately as well. It's only been happening since I installed my current ROM (Trigger 2.7).

 

[Sdobron]

Noticed this just now as well...might have something to do with the mods to show H or 3G.

 

[CrazyCharlie]

I wonder if it has anything to do with signal strength. I know that shouldn't make a difference but I can't think of any other reason.

 

[ATrueJesusFreak]

Noticed this just now as well...might have something to do with the mods to show H or 3G.

I would agree, but I went to my settings/ phone info/ signal page and the reason it was changing was because it was physically switching between UMTS and HSDPA.

Why? I have no idea.

I do live in a T-Mobile 4G enabled area, though I am not on their so called "4G plan".

I did notice that it did not have this switching problem on Bionix Frost-u2.

So, if anyone has some insight, please help us all understand

 

[ATrueJesusFreak]

I wonder if it has anything to do with signal strength. I know that shouldn't make a difference but I can't think of any other reason.

I was just watching my signal strength change and it doesn't seemed tied to the change from 3G to H.

For example, it would be around 67dBm and be on UMTS. Raise to up to around 75dBm and be on UMTS. Then it would switch to HSDPA and still be at 75dBm or sometimes lower down to 69-72dBm and still be on HSDPA.


So with that type of cross-over stats, I would be skeptical of that solution.

 

[RCinFLA]

HSDPA is a temporary data link. If it was on continously the phone would have very poor battery life.

When network server has a data packet for your phone it 'pages' up your HSDPA capability. Your phone can also request HSPA to initiate a data transmission.

The HSPA paging process is similar to receiving and initiating a voice call.

If no more packets have qued at their server or received from your phone after some period of time it will revert to normal 3G battery saver cycling. It has to be re-paged up to reinitiate HSPA data link. The wake up HSPA function does add some initial delay.

 

[h4rp0on3r]

So is there a way to force it to stay on HSPA while tethered, for example? (Or always)