[Captivate Android Development] thekurrgan:
Before I begin my thoughts heres the general info requested:

Carrier is AT&T

Purchased late august

ROM: Currently on my own JPY hodge-podge not worth posting up. Problem exists.

MOdem: UGJK4 / All others.

Theory: I previously was blaming the captivate's modem and not being able to deal appropriately with the given modem firmware i'm using, however recently I discovered something that doesnt all together quash the idea, but certainly added doubt to my belief it was the captivate at all, OR the modem firmware.

Situation: I have a great deal of knowledge of the towers in my area, so I know where most of them are and their UMTS site ID's / scrambling codes. These let me know what sector OF what site i'm connected to.

I have tested the following theory with 3 cell sites, 2 of which I KNOW AT&T is currently screwing with, and 1 which I'll call Site A, a site that has been working good for over a year. (At my current work place)

Theory: Its not the captivate / rom at all. Its the HSUPA screwing up AT THE TOWER.

Here is my reasoning.. I also have an iPhone4, which is the only other device at the moment to my knowledge using HSUPA on AT&T that can be purchased for AT&T. In my trival testing of speed once, I decided to use the iPhone 4 as a control, seeing as how it in theory has an "Official" AT&T HSUPA radio in it and is in theory "supported"

It was when I decided to do the side by side comparison that I discoverd the iPhone 4 did the same thing.. dropped connection during the test, USUALLY when upload was testing. Both did the exact same thing. After a couple weeks and a little bit of screwing with the captivate and the continued observation I decided to test this..

Site A (Known good, at least as good as ATT gets)

Site has 3 sectors. called X, Y, and Z for the sake of this post..

Sector Z is the most populated sector. It's what I'm usually hooked up to. Because we are an entertainment facility, I have some other useful data..The disconnection only occurs when the facility is busy..

So on a busy day I ran 5 tests.. Both devices dropped to E during the test. I then moved myself to an area inside the building that will default to another sectory, the X sector.. This sector is pretty busy also, and the problem was less, but still there.. I then walked around to the back side of the building and got on the Y sector, the almost non used sector.. and the problem went away. I could get neither phone to drop this time. So I waked back in and did a test when I was back on the Z sector, problem remained.. later on when people cleared out, Z sector started working great again. The problem is replicable on 1 other site that I know the sector aiming, and consistently the problem occurs on the busier ones. Then the 3rd site never has the problems. It also happens to be the biggest site in my area with 8 sectors.

I am no longer thinking it is the Captivate as much as it is AT&T either having capacity issues or incorrectly configured the sites for HSUPA, which IS possible to do. I have verified the towers also do not drop UMTS ever for non HSUPA devices such as stock captivate and iPhone 3GS.

So far I have found no connection with the phenomenon and modem choice, nor have I found any other CSC data correlation as long as the APN is correctly configured for AT&T.

Just my .02 hope it helps.