[HD2 Android NAND Development] cmylxgo:
Ok...let me elaborate a little on these settings for you.

ro.ril.hsxpa indicates hsxpa support of the target network:

-ro.ril.hsxpa=0 – UMTS r99

-ro.ril.hsxpa=1 – HSDPA

-ro.ril.hsxpa=2 – HSDPA/HSUPA

-ro.ril.hsxpa=3 - HSUPA+

ro.ril.gprsclass indicates the GPRS class of the target network :

-Class 2 : 3 slots : 8 – 12 kbps upload / 16 – 24 kbps download

-Class 4 : 4 slots : 8 – 12 kbps upload / 24 – 36 kbps download

-Class 6 : 4 slots : 24 – 36 kbps upload / 24 – 36 kbps download

-Class 8 : 5 slots : 8 – 12 kbps upload / 32 – 40 kbps download

-Class 10 : 5 slots : 16 – 24 kbps upload / 32 – 48 kbps download

-Class 12 : 5 slots : 32 – 48 kbps upload / 32 – 48 kbps download

Looking at the provided build.prop I see that ro.ril.hsxpa=3. This is not a valid value from what I know. However, this should not affect AT&T users since they can not use 3G aka HSPDA. The variable that I think is causing the issues is the ro.ril.gprsclass. This is the 2G network radio that works on AT&T.

Using your examples above:

Class 8 indicates 4 receive slots and 1 transmit slot

Class 10 indicates 3 receive slots and 2 transmit slots

If you primarily use your phone to download content from the internet, email, and other data heavy information Class 8 will provide you with better performance. Class 10 takes away 1 of the receive slots and gives you an extra transmit slot, this will be helpful if you send a lot of email, MMS pictures, transmission of large files or data. Looking at Class 12 I am not sure how they get that amount of data up and down only using 5 slots.

Going a little deeper...

ro.ril.hsdpa.category indicates the HSPDA (3G) catagory of the target network :

-Cat 1 = 1.2 Mbit/s

-Cat 2 = 1.2 Mbit/s

-Cat 3 = 1.8 Mbit/s

-Cat 4 = 1.8 Mbit/s

-Cat 5 = 3.6 Mbit/s

-Cat 6 = 3.6 Mbit/s

-Cat 7 = 7.2 Mbit/s

-Cat 8 = 7.2 Mbit/s

-Cat 9 = 10.1 Mbit/s

-Cat 10 = 14.0 Mbit/s

-Cat 11 = 0.9 Mbit/s

-Cat 12 = 1.8 Mbit/s

-Cat 13 = 17.6 Mbit/s

-Cat 14 = 21.1 Mbit/s

-Cat 15 = 23.4 Mbit/s

-Cat 16 = 27.9 Mbit/s

-Cat 19 = 35.3 Mbit/s

-Cat 20 = 42.2 Mbit/s

-Cat 21 = 23.4 Mbit/s

-Cat 22 = 27.9 Mbit/s

-Cat 23 = 35.3 Mbit/s

-Cat 24 = 42.2 Mbit/s

-Cat 25 = 46.8 Mbit/s

-Cat 26 = 55.9 Mbit/s

-Cat 27 = 70.6 Mbit/s

-Cat 28 = 84.4 Mbit/s

ro.ril.hsupa.category indicates the HSUPDA (4G) catagory of the target network :

-Cat 1 = 0.73 Mbit/s

-Cat 2 = 1.46 Mbit/s

-Cat 3 = 1.46 Mbit/s

-Cat 4 = 2.93 Mbit/s

-Cat 5 = 2.00 Mbit/s

-Cat 6 = 5.76 Mbit/s

-Cat 7 = 11.5 Mbit/s

I have tested differnt settings on my HD2 and going up in settings to gain speed has had no real impact. However, i have not been able to test on GPRS yet. Our HD2s are not capable of HSUPDA so these values don't really matter.

What we really need here is someone with an Inspire to dump their build.prop. Or i guess i can go find a build and download it and look.

-CMYLXGO

EDIT:

Found AT&T Inspire Settings...

ro.ril.gprsclass=10

ro.ril.hsdpa.category=10

ro.ril.hsupa.category=6

ro.ril.hsxpa=3

It also appears that ro.ril.hsxpa setting of 3 is for HSUPA+ (4G).

It also appears that ro.ril.hsdpa.category goes all the way up to 32, but 28 is the upper limit setting for the HSUPA+ setting for ro.ril.hsxpa setting.

Based on all the info I have been reading on some of these other settings I do not see how they can affect the HD2 on AT&T. The only one that might fix the issues is the ro.ril.gprsclass = 12