Posted on 09/09/2010 5:51:29 PM PDT by Swordmaker
Apple has re-introduced field test mode in iOS 4.1, which will allow you to quickly check the quality of your cellular signal by simply dialing: *3001#12345#* and pressing Call on your iPhone.
The signal bars on your iPhone will be replaced by a number. The higher the numeric portion of the negative number gets the worse your signal is. For example, -100 is worse than -79. If you tap on the displayed number the display toggles between displaying the number and the normal signal bars. The original field test mode had a more robust set of features being reported, but signal strength is all you get in this version.
Try the test for yourself and during the test hold your iPhone 4, the wrong way, by connecting the two metal bands on the lower left corner with your finger or hand over the black plastic strip. You’ll see the phone’s signal quality drop rather drastically due to the iPhone 4 death grip. According to AnandTech they were able to make calls and remain on that call with a signal strength as low as -113 on their iPhone 4.
If you are done testing simply press the Home button to return to your iPhone Home screen.
This is an interesting development considering the fact that Field Test Mode vanished in iOS 4.0 when it was released along with the iPhone 4 and the subsequent Antennagate scandal that rocked the Internet.
[via Gizmodo]
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Alright, here is my legit question. Is this a digital signal or analog? That means if I have a 65 does it SOUND better than a 110? Twice as good? No difference?
I know with old AM radio and analog sound slowly slowly falls off.... but is that how this works on the iPhone or does a 12 vs 112 make NO difference, as long as it stays connected?
Radio waves are analog.
It’s a measure of reception strength. The higher the number, the worse your connection is. This number is graphically represented in bars. Higher number = lower bars.
That was 100% NOT my question. Was I unclear? Or is this an attempt to spin the story? Sorry if that sounds bitchy but on these threads I can’t tell the mistakes from the intentional FUD. Thanks.
You asked if the signal was analog or digital, and if there’s a difference between a measure of 12 and 112. Both questions were answered: yes, the signal is analog, and yes, there is a difference between -12 and -112: -112 means your signal is weaker than -12.
There’s no spin or FUD here. You asked two questions, they were answered. If you don’t feel that you’ve learned what you intended to find out, then rephrase your questions rather than attacking people who reply to you.
Yes it was. You asked:
Is this a digital signal or analog?Terpfen answered:
Radio waves are analog. It’s a measure of reception strength.Please calm down.
What you MEANT to ask was, does the signal strength translate into a degraded signal across the range, or is it a threshold phenomenon where >Thresh means it works and <Thresh means it does not?
Right?
> I know with old AM radio and analog sound slowly slowly falls off.... but is that how this works on the iPhone or does a 12 vs 112 make NO difference, as long as it stays connected?
Think of it this way:
1. Suppose that there was some low signal strength number, say "-100", where the call would start to break up, and below which you were likely to lose the call. But let's say that at -99 and above, it sounded about normal.
2. With more signal strength (as the numbers went up from -99 to say -10), the call quality won't improve, because the extra signal strength is essentially "excess" -- unnecessary, wasted, if you will. And that is around 90% of the useful range of signal strengths.
3. Therefore, over most of the useful range of signal strengths, you won't see much if any difference in call quality. It is only at the point where signal strength is low enough that it starts breaking up, that you hear a difference.
Make sense?
My post was CLARIFIED by 75 words. You chose to reply to 6 of them. Ignoring the other 69 words which formed the entire context of the question.
There is a reason WHY I added 69 words following the 6 upon which you posted. Because on these thread FEW wish to discuss FACTS and seek to PUSH an agenda.
I then asked if that was your goal on my second reply.
Seeing as how all you did was AGRUE about how right you were to technically answer about 6 of my 75 words in my post and again NOT acknowledge the existence of the other 69 words, shows CLEARLY that you are not GOING to answer my question, likely do not KNOW thew answer and are only engaging in a direct diversion.
So, since I posted the question to someone else and since you DONT seek to answer it, stop now. I will not reply to anything further you post.
Generically, yes. That makes a perceived sense and obviously most people, myself included would assume that a lower signal was going to do something, but my question is VERY specific in seeking an actual known answer.
When does a call become effected where it matters? It is 102? 104? 144? What other factors effect this? If it is analog, and not JUST the signal itself, but the PROCESS, then 12 will be and will SOUND better than 24, which WILL be better than 64 or 104...
But, if it does NOT work that way, if the process is somehow DIFFERENT than we have become accustom to believing, then does it make ANY difference? Can you HEAR the difference between 4 and 144 if the call is not dropped? Between 24 and 64? In traditional “radio” the answer is YES and the curve is a natural dropping curve.
So, my understanding would be UNSURE in the case of HOW this works. What these numbers MEAN? Not in some general theoretical way, but in an exact and real world way.
Does it effect DATA? Does a 24 move FASTER than a 64 or 104? Or is ANY connection the same, so long as it IS connected?
And of course the WHY behind it. Not some “ I think so” but the HOW and WHY.
We have been discussing the signal issue for MONTHS and it is still unclear if it MEANS anything. So now we have this app... and I want to know...
Exactly WHAT it means. No spin, no guesses, no diversions, if anyone KNOWS, share. If no one knows, so be it. I’ve been avoiding these threads because they no longer contain INFORMATION and have become totally about POSTURING.
It's a lot more complicated than how you're looking at it. Call quality is simply a function of signal strength.
Moreover, the numbers are at best approximate, and on half a dozen phones placed next to one another you'll get half a dozen different readings. Maybe not wildly different, but I would not be surprised if say the average was "-50" among half a dozen phones, then you might see a spread from "-35" to "-65". Would not surprise me one bit. Gaussian distribution, probably.
So don't get hung up on the numbers. Think approximations and rough ranges.
> Can you HEAR the difference between 4 and 144 if the call is not dropped? Between 24 and 64? In traditional “radio” the answer is YES and the curve is a natural dropping curve.
I would be astonished if you could hear a difference between -24 and -64. Between -4 and -144 is one hell of a range, so maybe you could tell the difference there, assuming the call didn't break up.
> Does it effect DATA? Does a 24 move FASTER than a 64 or 104? Or is ANY connection the same, so long as it IS connected?
I don't know for certain, but I would bet a fancy dinner that the better the connection, the better the data rate. Why? Fewer errors, therefore fewer re-tries and re-transmissions. You might not hear a difference, because the errors are being corrected in real time and audio is lower bandwidth, so less affected by the effective bandwidth dropping due to errors. But high-speed data transmissions are a lot more sensitive to error rates.
"...Call quality is NOT simply a function of signal strength..."
Sorry, bad editing and lack of proofreading.
Think of it this way. With analog TV you get snow and hissing with a low signal. With digital TV you get video blocking and choppiness. With analog sound you get hissing. With digital sound you can get choppiness, you ca_’t __ar every__ing the c_ller is s_ying. There’s no sudden “now you get voice, now you don’t” line, but you won’t notice any difference going down the signal strength until you hit a certain point where reception problems are noticeable, and then they get worse until you have no voice.
Take your medication and settle down.
Thank you. But some people are... difficult, apparently.
iPhone 4, running iOS4.1
Have double and triple checked - I entered the above exactly and hit CALL. Screen dims and gives me the message “Your vote was not understood and was discarded”.
Someone got a clue?
OK - the number above leaves off the final “*”... worked with that.
Sitting here at my desk, it read -95. I tried every conceivable grip I could come up with - from two fingers tried all along the edge, to literally wrapping my hand all the way around the phone, and every variation I could think of, including the “death grip” pictures I found online..
Got it “up to” -101 one time (wouldn’t that actually be “down to”?) But most of the time it stayed steady at -95 Got -99 one time.
SO - I guess if I was where signal was right at the very minimum to make/receive a call - and i gripped the phone JUST right (or wrong), I MIGHT have a problem... maybe...???
Which is analogous to digital TV as well - that is why fringe signal areas result in pixelated TV picture (off-air), but once you are close enough (enough signal) to no longer have the pixels/checkerboard - the picture really doesn’t improve.
Phones work similarly - they require a certain baseline signal to operate. Anything below and they just don’t work. Is that better or worse than the older “analog” phones? Well - they might stretch your usable range - but call quality was directly tied to signal strength - better signal, better sounding call. I remember conversations via analog cell phones that were more like screaming exchanges than conversations!
Now - you may drop a call, or have one come in-and-out, but usually the actual call sound is not that much different. I have often used my phone with “one bar” of signal with zero call quality issues. I have had big issues sometimes, even with 4 bars+...
it's neither... Sound has nothing to do with it... The information is digital... the signal is analog. Even the voice signal is converted to digital 1s and 0s before being sent out... and it's received as 1s and 0s and then converted back to analog (sort of) sound at the speaker.
The scale is DeciBels... ANd if I recall correctly, it is Logarithmic... each ordinal number change is ten times greater than the last ordinal number. This is INVERSE logarithmic. Ten times weaker than the last number. And to confuse matters even more it is "DECI (tenths) BEL" So each Ordinal is actually in the tens position... but even the "tenths" are not equal in strength from 1 to 9. Follow me?
The DIGITAL signal, a series of 1s and 0s, is carried by the ANALOG radio waves.
When the signal is strong, it is easy for the receiver to distinguish the rapid digital ons and offs that represent the 1s and 0s. As the signal gets weaker—i.e. higher negative numbers measured—the ability to distinguish WHEN a 1, becomes a 0, or vice verse. becomes harder and harder. As that signal strength weakens more and more, it becomes more and more difficult for the receiving unit to filter out the noise. Most systems have a correction system built in using a "check sum." If a running total of count doesn't match after a given number of signals, then the system request the last batch of data be repeated, assuming that an error was introduced by noise. This repetition slows down the transmission of data. At some point where the signal is so weak that background noise becomes louder than the data and overcomes the useful information, the errors have overwhelmed the ability of the system to correct itself. The system gives up telling the sending station to repeat itself, the signal is considered "lost," and the call is dropped. The system has an algorithm that determines at what percentage of errors or noise to data the system will give it up as a lost cause.
Usually, from what I've read, a digital cell phone will still operate "fairly" reliably down to about -112 to -124 dBs... that's a pretty weak signal and usually represented by less than one bar on the bar display... and that's long after you could not make out what was being said on an old analog voice system... but you'd experience a lot of dropped calls.
RachelFaith, I hope this explains what you were asking...
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