[HTC One S] Rapier:
Everything started when I've made some tests and I've noticed some strange things:

- on every KK ROM I've tested, mobile data drops completely after some talk time. It is happening only during calls (long calls usually). It is regardless of the radio used, I have tested it with 1.13, 1.15 and 1.20...the same with all. It is also happening regardless of the call type: on BT (car-kit or headset), speaker, headset, handset. EDIT: Now I made some tests and seems like I don't have this issue anymore but instead I have the issue below. I don't know why and when this started to happen

- as soon as I make a call, the mobile data icon switches from H/H+ to 3G. As soon as the call ends, it switches back to H/H+. I've run some speed tests and it's not only the icon, it's the speed too. I get about 0.09 Mbps during a call with the 3G icon and up to 8 Mbps when not in a call with the H/H+ icon.

Now there are some build.prop entries I don't understand and I couldn't find any explanation on them. There are many threads in which some of them are recommended, some say they work, some say they don't, I am really puzzled. Below there are a few about I couldn't find any details:

- ro.ril.radio.svn = usually value here is 19 but I heard about 01, 02, 03 or 04 as well. Nobody seem to know why it's one or another and more important what does this does.

- ro.ril.hsxpa = usualy 2 but I saw many people recommending 3 or 4 without any arguments on that. What does 3 or 4 do here? Don't say it's enabling HSDPA or HSUPA because the lower values already do that: 0 = UMTS, 1 = HSDPA, 2= HSDPA/HSUPA. So why 3 or 4?

- ro.telephony.ril.v3 = now this is a nice one. Mostly I've seen this set as skipradiooff but I found more: icccardstatus, skipbrokendataca ll ,datacall, signalstrength, facilitylock. What's this all about? What any of these options do?

Now why I ask such stupid questions you'll say. If they work who cares...ok, but DO they work? Has anyone tested if they change something? If yes maybe those persons could bring some light here because nobody seems to know. And I mean if one of the above do change something, the ones that tested and recommend these settings should at least tell us what happens if one or another option is included.

Has anyone commented out for example the ro.ril.radio.svn and see what's happening? Or put 01 or 04 instead of 19 and see if any change? Cause I couldn't find any difference with this option set or not. Why is then recommended? Maybe it's particular to some carriers (I saw alot of settings related to US T-Mobile). If it's true, maybe it's good to know that only for that carrier it does something and on any European carrier it has no effect (or it has, I don't know)

Please anyone who knows some info or made some tests post here. Maybe we could shred some light into this cause after searching and searching I couldn't find anything clear. Everybody is mentioning those with one or another setting but nobody explain.

EDIT: I've start testing

ro.telephony.ril.v3 =icccardstatus - this seem to show a "no SIM" or "insert SIM" icon instead of the cell signal icon. Even so, calls CAN be made, I've tested a few. Probably this disables the ability to read SIM card status so that's why it shows that no SIM is present

ro.telephony.ril.v3 =datacall - this disables completely the mobile data. Icon for mobile data is gone and there's no mobile data access. Browser and any apps are reporting "no connection"

ro.ril.hsxpa = I hope it is not my imagination, maybe others can test as well but here's what I found. If 4 is there, most of the times I get H indicator and speed. If 2 is there, I mostly get H+ indicator and speed. So strange but at least in my case 2 seems to be better than 4 (which anyway I don't know what means). EDIT: Ok, after further testing and searching it seems that value of 3 means HSDPA "uncapped" and 4 means HSUPA "uncapped". So it could be that 4 is better than 2 or 3 but this has to be tested for each particular carrier to see if it's really improving something or not

ro.telephony.ril.v3 =skypbrokendataca ll was the fix (100% of the time) for a data acquisition issue on the HTC Sensation for TMOUS customers. Ironically, it causes a lot of 3g connection problems for non-TMOUS customers though. The problem it fixed was a blinking H or E with corresponding lack of data. Many times, sending a MMS would fix the issue as well, but not always. (thank you [MENTION=2207213]nicknc[/MENTION] for clarifications)