I was thinking about this for android since it's an open system but it probably applies to any phone once you XDA guys get them.
The idea is that since there is a Cell Phone radio in the phone, and there is a possibility to gain access to that radio is it possible to create a DOS attack in an area using just a normal cellphone? Imagine having an app to effectively block communications for what would probably be a very small area to keep it going long enough.
Does phone hardware even have the capabilities to do this?
Hypothetically, it should be possible, though I'm unsure of the level of access to the radios themselves in any phones...If you can get the radio to output noise on all frequencies constantly, with enough output, you should be able to jam a small area. However, the biggest issue (after gaining access to the radio chipset at the lowest level) would be pumping out enough power across the different channels to degrade others' reception.
You could probably get away with pumping out noise in intervals (extending battery life from your handset) and still degrade a signal enough to disrupt communications.
However, encrypted signals may be able to overcome brute-force jamming to a certain extent...I'm not sure if cellphones use spread-spectrum or frequency hopping, but if they do, there's another issue to overcome.
Keep in mind, if anyone clues in to the jamming, law enforcement radio direction-finding equipment will pinpoint the jamming headset pretty quickly, since you need to output a more powerful signal for your jamming to be effective.
cell phone jammers are also highly illegal.
It was a thought that came to my mind and I understand they're very illegal but I was wondering. Mostly for the capabilities of our phones, mostly the android ones.
I think it's a pretty interesting topic. Not sure I've ever heard anyone think of this one before on the forums (I don't post a lot but I read a lot)
only government officials can use cell jammers in case of bomb threats and stuff like that
You can buy jammers online if you know where to look for peanuts. Outside the USA some places have been using them as casually as in theaters. I also heard similar reports in hopitals but that surely has to be rumour mill since the whole point of no phones there is to reduce electromagetic interference messing with equipment like in planes so why would you spam with even more? (I think jammers DDOS the airwaves rather than anything much intelligent?).
The modem section of android has AFAIK always been closed source. This put a spanner in the works for things like the Replicant project which was trying to build a truely transparent phone open source so that you always know what is going on and have some privacy. The furthest they got was pretty much everything apart from the modem open source and that modem was able to spy on everything else.
Basically the network owners want a tight rein on what's connecting to their networks and the spectrum licensees want control of the spectrum. This is something both have at the moment legally...
but what with software defined radio like GNU Radio is pretty impossible to enforce and the only thing delaying this change is the economics of software defined radio and it's size. I expect this will change over time and that could be another very disruptive and interesting technology. As such I expect it'll try to be repressed making the problem worse.
That said, there are plenty of modems now for Arduino like projects and I'd expect just one of these to be open source?
Hope this helps clear it up for you
-j
This isn't the type of discussion that XDA encourages, especially not a discussion that's over a year old. Thread closed.
Related
I am trying to find out if there is a limit on how many phones can establish a data connection to the same cell tower at the same time.
Here is why: 4 users in the same room on Cingular's network. Two can connect to Edge network and get service and two can't. Sometimes all have Edge and sometimes only one. It seems random. The office complex where this happens is full of other people also having cell phones, not all the same provider but probably many also use Cingular... we don't necessarily have that much choice ;-)... The office also happens to be near a very busy shopping mall.
I've been doing some reading about the channels (on HowStuffWorks) and it talks about a certain amount of channels being available. So I figure the reason why sometimes some of us lose connectivity is due to the tower being overloaded - too many people accessing the tower at the same time.
Does anyone have some data on how this all works, or where I can go to find out about it? Does someone work with this stuff, like putting up towers for one of these cell phone companies, who has experience with this? I think it would be of interest to others, too.
Sadly Cingular isn't much help... "Maybe you sweat too much and got your phone wet and that's why..." can you believe he actually suggested that? We even had Cingular replace one phone which was particularly prone to this phenomena, only to find that it didn't change.
Food for thought....
alright first off before i ask my question i think all of you should know. i am an extreme newb to cell phone hacking and moding so please excuse my arrogance 2nd thing i do most off my posts off my cell phone so please excuse the bad grammer and spelling. anyways as i have been reading in the forum people list the mods to their phones and i notice one listed radio? so could someone educate me on what a radio is i figure that it is what keeps you conected to the service provider but other than that i am clueless so when you mode it do you physically open the device and replace something and 2 what is the point of changing the radio do. so could an expert educate me and feel free to tell me everything you know rather than just answering my 2 main questions.
I guess thats its the radio you use to listen to music, news etc... Most phones nowadays come equipped with built-in radio function. I hope that helps. =)
im not too sure about the exact thing you are talking about
however thats what a buddy of mine working in a cell repair shop told
for the radio(the one that broadcast phone signal not the radio you listen to)
you know that in order to use a 3g phone in the US or elsewhere
[but the problem is mainly US cuz here we use special 3G band compared to the rest of the world] you need to get the good frequency
however most of the time manufacturers only design and produce different radio chip for different region if they really have to
cuz you know running those factories is not given to anyone
and why redesign a phone when you already have one
a phone is like a computer.. "change a part, gotta change the whole part" concept..
however a phone might not work in certain 3G frequencies not because the radio cant but because the manufacturer didnt pass the regulations in those regions and it happen that the phone can be 3G but its locked in the ROM
so you need to mod the ROM to make 3G radio work
like the omnia
some ppl argues that it might be dual-UMTS but the US 3G is locked in the ROM
because samsung didnt pass the FCC(Federal C??? C?? the agency that rules communication) at that time(when the first omnia shipped)
so they couldnt put US 3G
same thing for the touch diamond but it was GSM that needed to be rom-unlocked
d3thstalker said:
I guess thats its the radio you use to listen to music, news etc... Most phones nowadays come equipped with built-in radio function. I hope that helps. =)
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Click to collapse
Not the right kind of radio bud
vanilla_star_8 said:
im not too sure about the exact thing you are talking about
however thats what a buddy of mine working in a cell repair shop told
for the radio(the one that broadcast phone signal not the radio you listen to)
you know that in order to use a 3g phone in the US or elsewhere
[but the problem is mainly US cuz here we use special 3G band compared to the rest of the world] you need to get the good frequency
however most of the time manufacturers only design and produce different radio chip for different region if they really have to
cuz you know running those factories is not given to anyone
and why redesign a phone when you already have one
a phone is like a computer.. "change a part, gotta change the whole part" concept..
however a phone might not work in certain 3G frequencies not because the radio cant but because the manufacturer didnt pass the regulations in those regions and it happen that the phone can be 3G but its locked in the ROM
so you need to mod the ROM to make 3G radio work
like the omnia
some ppl argues that it might be dual-UMTS but the US 3G is locked in the ROM
because samsung didnt pass the FCC(Federal C??? C?? the agency that rules communication) at that time(when the first omnia shipped)
so they couldnt put US 3G
same thing for the touch diamond but it was GSM that needed to be rom-unlocked
Click to expand...
Click to collapse
This is what i understand about radios (the cell phone kind )
Your radio is what communicates with the tower and can affect how many "bars" you get. Not having the correct radio will also cause your phone
Camera not to work, to have a black screen, and/or to have no sound or intermittent sound.
The radio chip stores information, but you can change the information on that chip by "flashing a new radio."
This is just my own understanding so if i made a mistake don't be afraid to correct me
I believe the radio part of these devices is the information that tells the hardware in the phone how to act. What frequencies to use on the cell band, how the wifi antenna acts, how the bluetooth antenna acts, etc... Even how the GPS antenna works. Hence while in CDMA land my Titan needed a GPS enabled radio to make the gps work. There was a chip and antenna in there, but the radio excluded directions for the processor to interact with it.
My mind is simple, and this may be wrong but it is how I understand how the radio portion affects the phone.
Also, feel free to correct us if we are wrong!
Wow... Where.... wow.
Radio function
Radio is the whole function of the cell phone part of your tiny portable PCs your carrying around.
Its a
Duplex (transmits and receives separate carrier waves at the same time) ,Two-way, VHF and UHF, FM tranceiver in its purest form.
The cell towers are nothing more than ham radio pioneered "repeater" stations, connected to land phone lines. 20 years before the 1st commercial cell phone, HAM radio operators were setting up their own area "club" repeater stations, and networking them much like cell phone operators do now. The biggest rush of my young electronic life was carrying a kenwood TR-2500 FM handheld with me on my Yamaha YZ-80 out to the remote areas of our trails, and making a phone-patch call from the handheld thru the repeater and to a household phone. It felt like star trek man. I felt so high tech and up to date as a 15 year old carrying a radio my license didnt allow yet. LOL The funny part was everyone who was on frequency would get to hear your conversation too. Modern cell phones are the same thing only with collars and leashes.
So , back to the PDA with a two meter radio crammed tight agaist a computer with buttons that are too small ...
Thats really what you have.
Everything that a PDA is , outside of Radio [ a patch(voice) connect or a modem(data) connect] is just a small computer.
By the way, I raised the room temp tonite by leaving a Touch Pro turned on and Idling its data connection ...
Circuit... great explanation! But how do I know what Radio version my X1i needs?
In Smartphones and Pocket PCs, 'Radio' refers to the RIL. Radio Interface Layer. An API (Application Program Interface) that sits between Windows Mobile and the hardware driving the phone. An API is a published series of functions/methods that an application or operating system can call.
Ther is a patent for it at http://www.patentstorm.us/patents/6826762.html.
It is so that the transmitter/receiver sits at arms length from WM or its apps, i.e. you can't go POKE the phone's registers directly, you have to ask pretty please through the API.
The Radio part of the ROM is the version that this API is at, for your device.
Hello,
Flying from London to Baltimore in a couple of weeks and looking forward to some quality gaming time with my xoom . Wanting to use my ps3 pad with sixaxis app but unsure what rules are regarding bluetooth during a flight. Had a google search and read mixed reports on using bluetooth. Any advice?
Just use it nothing is going to happen its all bull**** the plane is gonna have interference or and all have a safe journey mate cheers
Sent from my Xoom using Tapatalk
To be honest, radio frequencies do not interfere with aviation equipment outside of their operational range. It is the same concept as your phone, do you randomly pick up another persons call while you are talking on the phone.
We are bombarded with astronomical amounts of radio frequencies every day, the only thing that changes is how strong each one is. Phones, bluetooth, these devices can not physically put out enough power through their radios to cause a problem. Besides, bluetooth signals start to drop off by 20ft out usually, and most of the time cut out by 30. Bluetooth, and NFC are the weakest everyday radios in mass use.
I say go for it, and if they bring it up, just put it away, or argue that its infrared. That one has saved me once before.
Most airline policies say no to BT. In reality, that's silly. Many airlines now sell WiFi on some flights - and that's far stronger than BT.
I seem to recall seeing an FCC stamp on... oh, pretty much everything I own. Something about the device being tested not to cause any unwanted interference. Could just be my imagination, though.
Silly airlines.
Mythbuster actually did an episode on this topic and did find that Cell Signals can affect navigation but I forget what the power level was that made it happen.
BT should not be a problem with it's limited range and low power, and the truth is they only really care about it on Takeoff and landing where the instruments are the most important to the operation.
I've had several occasions when it feels like the network just stops doing its thing when it should still be active.
For instance, when updating my apps, it will update most, and then get stuck at 'downloading' one of the last few apps forever (keep in mind these are tiny downloads we're talking about).
Another example would be Facebook. There are instances when it seems like the network isn't activated or doesn't remain active when I try to view an image. It would get stuck at the loading stage and never get out of it unless I reload.
I'm starting to think this goes beyond a simple application bug and probably is firmware related? Anyone else have a similar issue?
Well I've had similar issues with my One X (AT&T). I definitely have the WiFi issue that some folks are talking about. I've had WiFi just kick off and say "not in range" when I am standing right next to my router.
With regard to the network, I have had multiple times (at least 5-6) where out of the blue I get no signal of any kind and have seen it last as long as 5 minutes, even when I moved around (at one point I walked for 5 blocks). This was in a large metropolitan area where I have never had a signal problem. My friend was with me and had no issues at that time on his Iphone 4 with AT&T.
I went to Best Buy yesterday and was lucky enough to have it do the same thing while they were looking at it. I'll probably return it for an exchange just in case it's an issue with this specific phone.
I am having the same issues as well - although it rarely happens. I will likely exchange it for another.
Similar issues here.
I seem to be suffering from all of the various bugs. Wifi, network signals, email push. When you add in the things that are apparently there by design, but might as well be bugs (multitasking issue; links to youtube and appstore opening up in browser windows instead of the app), I'm pretty dissatisfied with my overall experience.
Hardware and screen absolutely fantastic. Software... way buggy.
chrikenn said:
Similar issues here.
I seem to be suffering from all of the various bugs. Wifi, network signals, email push. When you add in the things that are apparently there by design, but might as well be bugs (multitasking issue; links to youtube and appstore opening up in browser windows instead of the app), I'm pretty dissatisfied with my overall experience.
Hardware and screen absolutely fantastic. Software... way buggy.
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Click to collapse
Same here for all of the above. Love the phone 95% of the time, but it does random things (like drop network connection) 5% of the time that drives me nuts.
Has anyone ever seen it switch to 3G? Mine will drop to no signal with 4G still displayed when I know there is plenty of 3G coverage in the area...
honestly i thought the facebook one was just a facebook problem... because i've had that with every android phone i've ever owned across two carriers (T-Mobile and AT&T). it is annoying though.
polarbearmc said:
honestly i thought the facebook one was just a facebook problem... because i've had that with every android phone i've ever owned across two carriers (T-Mobile and AT&T). it is annoying though.
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Click to collapse
Nope. Happens to me in all programs using data. I also had the same issue with Facebook on past android phones, but that isnt the problem this time.
So is it safe to say its most likely a software/firmware problem? I got my phone through Amazon so exchanging it is more of a nuisance.
S8B said:
So is it safe to say its most likely a software/firmware problem? I got my phone through Amazon so exchanging it is more of a nuisance.
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Click to collapse
I am pretty sure this is a firmware issue. Remember, this is the first ICS HTC phone. There were bound to be bugs.
I don't think this is faulty hardware given how many people are having issues and given how my similar issues have seemingly disappeared. I believe it is a combination of software just AT&T's network. I don't think their network is quite as ready as it should be for this phone. There aren't many LTE devices on AT&T but the more there are the more issues there's bound to be unless they move at a slower pace and work them out. I mean it's just a logical trade off between having a network that grows very steadily vs. one that spreads rapidly to capture more attention and users. They want to roll out LTE to as many cities as possible, but they could simply be doing it cheaply (edit- there is NOTHING cheap about it, but let's say "more cheaply" than a slow and steady approach). From what I've read on the interwebs there they don't have complete coverage in certain areas, they skip a few towers So overtime, I would expect this issue to get better through software updates for the phone and just general network infrastructure reinforcement. Also keep in mind they don't have volume testing, only spot testing. Download the AT&T app that lets you report when you don't have good signal. It helps them.
https://play.google.com/store/apps/details?id=com.att.android.markthespot&hl=en
Too bad they didn't pre-load this app instead of all the others
Also worth a mention that AT&T took an interesting path with their "Circuit Switch Fall Back" (CSFB) system and I'm fairly certain it's a bit more complex than it sounds...I would be willing to wager several firmware/radio updates will come out in the future to help improve how this works. If I was a betting man, I would also bet that getting dropped from their network would be a result of this in many cases. Of course bad signal is a very common and simple reason, but I also think it would be foolish to assume CSFB would just work without any glitches. Although I do like the idea vs. what Sprint is doing (which is I'm sure not their preferred solution, but I guess buyer beware when it comes to these big companies investing in major infrastructure matters).
---------- Post added at 09:46 PM ---------- Previous post was at 09:35 PM ----------
ROFL - I loaded up the Mark the Spot app and realized it said at the bottom "Don't use this app while driving." ... Not sure I've seen that before on an app, but what a nice responsible thing to add. I'm sure they of course mean don't use it while moving fast because your position won't get accurately marked...But eh it's nice to think they meant it for safety.
Hi guys. I've got a saga to describe for those of you who are interested, but I'll try to keep it brief. I think it really boils down to one or two simple issues.
I've had Verizon phones for a long time, in Central Illinois. Probably about 10 years now. Rarely had problems with dropped calls. My previous phone was a Droid 1 ... worked great, very rarely (as I recall) had dropped calls.
Then in January 2012, as the Droid was killing me with general Android lag and unresponsiveness (but voice was still fine), I upgraded to a Galaxy Nexus. Loved it for Android performance. For the first 3 or 4 months I had it, I don't recall it giving me any undue trouble .. dropped calls were minimal if any, I think.
Then sometime around April or May, started getting a ridiculous number of dropped calls. Mostly at my home, throughout the day, but not just there, I've also experienced them a mile or two away from my house. The neighbor hood is fairly wooded, but that's never been a problem before.
Additionally, my wife has a "feature phone" (non-smartphone) also with Verizon and very rarely if ever has dropped call problems.
The topography at my house is along a river, we're right near a high bluff overlooking the river, with line of sight (besides the trees, of which there are not a ton, really) for at least a mile or so across the river. I think we're possibly within range of several cell towers.
I notice at most points when I'm in my house, using some apps that help you track signal strength and show you the cell tower ids, that I'm mostly one just two different ones, both of which seem to be maybe about 1 mile away. Also, if I'm walking up one flight of stairs, I pretty reliably see that same app showing the phone switching among possibly as many as 4 or 5 towers, in the space of about 5 or 10 seconds!
I suspect this may be caused by the topography in my area.
I also suspect that most of my dropped calls *may* have something to do with being in range of so many towers, or with the phone switching too frequently (or unnecessarily, really) among the towers, while I'm on the call, if this is possible (I have very little technical knowledge of cell phone radio technology -- hence this post).
Now, I've done a fair amount of research and talked to Verizon customer support about this at length. They've actually been very patient and good with me, but we still haven't arrived at the solution.
I originally thought the problem my be the Galaxy Nexus, but after getting a warranty replacement on that one, and even getting to try a Droid RAZR and then finally the GS3, I'm seeing virtually the exact same behavior on all of the phones. The symptoms do *not* seem to be directly related to signal strength exactly. I get usually about 50 - 60% of the total bars (maybe 3/5 or 4/5) in most parts of the house, yet *still* get these persistent drops.
Verizon's final best solution for me, basically, was to use a Network Extender. Despite my misgivings towards this, I have acquired one and it does seem to solve the problem for me, when I'm home, and when I'm in range of the device (its range seems pretty good in my house). One big problem with it though, ridiculously, is it seems that whenever it's on, my wife's Verizon phone starts dropping calls (and it never does otherwise). So there's a Catch-22 there, added to the fact that I'd rather not have to be running a Net Extender *and* the fact that I still see other drops when taking a walk or driving at least a mile or two from my house.
So, for those of you still with me, I'm wondering if
a) my theory about excessive switching, etc., is plausible, or if you have another one based on the facts I've outlined
b) if doing something like flashing an alternate radio ROM (I barely even knew there were separate ROMs for the radio -- I've done some rooting before of Android, but not the radio) might give me some more control or better performance. It'd be great if there were a setting somewhere where I could tell the phone to be less willing to switch towers or to give a higher preference to one tower, at least while in a certain GPS area (I know, I'm sure it's a reach).
Anyway, looking for a little education into why your opinions are of what may be causing this and if I have any remedies available that are feasible and may actually help.
Thank you for your attention and expertise.