Original topic was if it's possible to use N900 as selective "scrambler" on different communications media. By "scrambler" the OP meant something like a signal jammer, affecting nearby UE's.

And there of course there exists an answer, too, and that is "not possible".

Indeed, whilst looking for something for my answer in another thread, I found that "scrambler" and "jammer" are often used interchangably. I don't get it: the two things are very different animals but there ya go.

@picho yup we have to accept that and kneel before the binarys kudos to the devlopers who coded such hard to hack codes oth is there any possiblity of doing other ?????? Things with the gsm hardware . Anything for fun or usefull if doable or we should not post in the thread as the topic is already over

Hmm talking about scramblers. I have only one question: WhY?

My real curiosity about the GSM chip and how it works/behave would be the next one:

2 years ago, I owned an LG Optimus One, and the stock ROM was bad, buggy and slow. So we started developing an ICS rom over at XDA. Okay, the weird stuff started about @ the 5th milestone of the project when we added some GRAPHICS libs (new adreno libs for ARM v6) and the GSM started to work weird and I say weird because it would intercept any SMS message from others phone in a close range. After we reached the next milestone in about 1 week the weirdness disappeared. We tried to recreate the conditions but the phone wouldn't intercept anymore...

So my question is: Was this a network problem, or was it, somehow, that SOMETHING inside the ROM interacted with the GSM chip and made it act that way?

That would be really awesome, to intercept SMS, and stuff like that, not scramble, what's the point of scrambling?

AFAIK it must have been either a network problem or an effect of something that was just misunderstood.
SMS:es are transported on SDCCH or SACCH, so it is impossible that one UE could intercept a message meant for another. If the transport was over some Common Control Channel then it could be possible but as it is...?
Only way an UE can access Decicated or Associated channels is by authenticating to the network as an endpoint and that requires correctly presenting your IMSI in the registration.

How was the effect observed, did you actually get access to all SMS messages in some cell or just messages targeted to a certain device?

True.

Well I was in a pub with some friends, the phones were on the table, and one friend received an SMS text from a common friend, and after about 2-3 seconds I got the sms too. I was no mass sms text because it was dedicated to that friend of mine. I read the sms and asked that guy, is this the sms you just received? And he was... HOW, HOW DID YOU GET THAT? Events like that happen that night, I even got sms messages that were not in my agenda, and when I asked those friends they were all very "WOW" about this problem. I didn't get sms from only one device, I got sms'es from device in a range of about 2-5 meters, if I would sit next to them, I would get their sms'es on my phone.

It was weird because we tried to recreate the conditions that got to this weirdness but couldn't. After 2 years I opened up the build archive again and tried to recreate the same conditions on my Samsung GT I-9000 but no succes, the "problem" never came up...

P.S. worked only on other Android devices, if the person next to me had a windows mobile smartphone, or a phone with proprietary os it wouldn't work... It wouldn't matter what Android version they had, it just had to be Android, my version was 4.0.4 beta based on CyanogenMod port.

Don't you mean ~17.5 x ~17.5 cm size?
Perhaps you could find something like that for Barbie at your local Walmart.

@kangal where you from

Moreover (caveat: I am no expert on these things so do not take this with any sort of authority), I would be very surprised if a delivered SMS could be delivered again even if your phone did authenticate as someone else's. I think the hint comes from the fact that they were all Android phones. Most likely your phone somehow tricked the others to exchange recent messages. Bluetooth malware, perhaps?

I have no ideea about any malware, but the bluetooth was offline just like the wireless most of the time (you know the battery problem on older android smartphones). I don't know, I really don't... But as I said this would be something that people would pay heavy money on the black market. A phone that can intercept messages or download any message list from a phone within a close range.

Another ideea. My Windows Phone right now have a function inside it, it's called Find my phone, and this function can track your phone even if it's offline or turned off (tested). In my case the phone have a sealed in battery so you can't remove that, and when in shut-down state it can still activate GPS, A-GPS and GSM to determine it's location and send it to Microsoft. This way you can buy/make a gift a phone like this and track that person.

How can I use my phone to track someone? First of all you set up a blank Microsoft account that you're gonna claim, and give away your phone to the person you want to track. That person is going to log in with a secondary Microsoft account or if the phone is working as is it's not going to log on with anything else except maybe Facebook, Twitter or Google. Then log in on your Windows 8 PC with that account and everything will sync with your pc: SMS, CALL LIST, PEOPLE, AND PHONE LOCATION. Ok, and that's with the Winodws, now if we could extend this concept to other phones like Android, Symbian, Blackberry, Maemo, MeeGo and why not Jolla, think of the money that will be paid by jealous husbands to watch their wives and vice-versa and why not, parents tracking their kids.

How? Microsoft don't need any connectivity from the phone (meaning as I said that the phone can be in airplane mode - full offline) and still get the location. A method like this we should use not to be network dependent, and think about this, who doesn't have a Facebook account? Meaning that that phone may go at least once a day online to check Facebook or Twitter or RSS or anything. While phone is online, a package should wait a secure upload, and trust me, how many SMS and call logs you should have to exceed 50-100kb? When you go online that package gets uploaded and decrypted on the account of the specific user.

How legal? This I don't know, but this of this. You hire a private-eye and that's legal? Why this shouldn't be? We are going to monitor that person for a specified time and give you a confidential report about that person after you agree a contract and you agree that your purpose is strictly personal and the data you receive will only be used in court or other legal authorities (like a divorce trial, or suing a bar because your underage son came drunk at home and he visited that bar as your watch log say). So I say this can even be legal in some way?

I am very interested to discuss this matter here!