Database Users

Wireless Frequencies - pros and cons

Hey everyone
I've been looking into wireless frequencies recently for a little project of mine and I have a couple of questions which I haven't been able to find the answers to in simple form.
Basically I am looking for the pros and cons of different mobile phone frequencies (ie 850mhz, 2100mhz etc). About the only thing I have managed to pick up is that the lower the frequency the better it can penetrate solid objects and also travel further.
I'm sure there must be more to it than this or otherwise we would all be using low frequencies for networks. Any help or further info would be appreciated and also if you could help explain why that is the case so I can understand it better.
Thanks!
Sent from my Nexus S using XDA App

as for everyone not using lower frequencies, maybe it has to do with Spectrum availability... for instance in US everyone's eyeing the recently freed white spaces in the 700MHz range, but the highest bidder gets them.
generally longer wavelengths are used in rural areas, and shorter in urban areas because they have more towers in place anyway can afford shorter frequencies.
But AT&T seems to actively convert to 850MHz anywhere possible.
for GSM, Mostly only 2G networks are now on higher frequencies, and for 3G with higher spectral power requirements, they try to use 850 to try to save power somewhere...

ap1618 said:
as for everyone not using lower frequencies, maybe it has to do with Spectrum availability... for instance in US everyone's eyeing the recently freed white spaces in the 700MHz range, but the highest bidder gets them.
Click to expand...
Click to collapse
I think it is a similar situation here in Australia. Telstra announced an LTE network for us but running on 1800mhz (old 2g spectrum for them) however by 2013 all analogue TV will be switched off so everyone is eyeing the 700mhz spectrum. I read somewhere however that if Telstra decided to use it the cost would be about an extra half a billion or so (presumably for licensing) .
I came across another bit of info (for wifi in this case but fit could be the same?) that higher frequencies can have a higher bandwidth (case in point here was 5ghz wifi). Could this also be true here and why some higher frequencies are used in cities and for LTE deployment in the UK (2600mhz I think).
Thanks anyway!
Sent from my Nexus S using XDA App

Bump! Anyone else have extra info to add?
Sent from my Nexus S using XDA App

Higher frequencies have the potential for higher bandwidth.
And Higher frequencies attenuate quicker, so in a RF dense area high frequencies are nice, as they fade away and you can hear closer broadcasters better.
Also one of them is higher energy to make, but I forget how that goes. So there is a power component to it as well.

Cheers LargePrime! That's something I didn't know so thanks for sharing. Would you happen to know why it has the potential for higher bandwidth?
Sent from my Nexus S using XDA App

This is rather High level, and a metaphor, so inaccurate.
Imagine Frequency as a metronome. A click is one cycle. Now lets pretend it's Jazz or something and we can screw with the timing on the metronome. When we do, that counts as a small piece of data. i.e. Short timing is a "0" and Long a "1".
With more cycles one has more potential to flow data.
Also Higher MHz has less wait time until a clock tick is going to happen, so less latency.
And Cheers to you!

Thanks for the explanation! I think I get how it would work. Yay for metaphors
Thanks again! I think I have all I need now!
Sent from my Nexus S using XDA App

side question for you... hows GPS on Nexus S?

Its been perfect! Never had a single issue with it in the month I've had it. Accuracy is <5m outside and about 10m inside. The lock seems quick too however I don't have another GPS device to compare it with.
No problems at all though, despite the Galaxy S GPS issues
Sent from my Nexus S using XDA App

oh wow! I dream of that day!
can u do me a favor? can u please post a pic of the GPS antenna?

ap1618 said:
oh wow! I dream of that day!
can u do me a favor? can u please post a pic of the GPS antenna?
Click to expand...
Click to collapse
Sorry what do you mean by the GPS antenna? Like the physical antenna? I actually don't know where it would be...

yes, for by now I worry worry for a physical antenna placement issue...
on the back of your phone, there should be a tiny gold connector... what you can do is to post a pic of the back with the battery cover off.
thanks in advance.

ap1618 said:
yes, for by now I worry worry for a physical antenna placement issue...
on the back of your phone, there should be a tiny gold connector... what you can do is to post a pic of the back with the battery cover off.
thanks in advance.
Click to expand...
Click to collapse
Can do, give me a few minutes I think I know what you are talking about, I always seemed to think it was for a mobile antenna extension or something
EDIT: Ok here it is sorry for the blurryness, I didn't realise it until it was uploaded but you can still see the connector.
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hmm this is super interesting... the two connectors, i believe they are are the GPS antenna. on captivate we only have one of them! While they look similar to what we have, you have two!
i wonder whether this last minute addition was sum and boost the signal with two antennas... damn

ap1618 said:
hmm this is super interesting... the two connectors, i believe they are are the GPS antenna. on captivate we only have one of them! While they look similar to what we have, you have two!
i wonder whether this last minute addition was sum and boost the signal with two antennas... damn
Click to expand...
Click to collapse
The two connectors within about 1cm of each other are actually the connectors for the NFC antenna on the backplate. Sorry to disappoint I think the GPS one is the single connector on the right hand side near the middle.

oh forgot about NFC. I have the exact same connector, except its only one. so one must be GPS and one for NFC...

ap1618 said:
oh forgot about NFC. I have the exact same connector, except its only one. so one must be GPS and one for NFC...
Click to expand...
Click to collapse
If they both appear to be the same, maybe it's just because of software differences or even location. Considering I'm in Australia and it looks like you're in America.

An Update.
Higher Freq take less power.

Okay thanks for that update. I presume it would require less power because it attenuates quicker and therefore doesn't travel as far?
Sent from my Nexus S using XDA App

Indoor signal strength

I know it's normal to get poor reception in industrial buildings but I'm not sure what to think. I've read the threads about the radio being locates right where it sits in your left palm and immediately noticed the left hand signal reduction does happen to me as well but only inside concrete buildings.
I'm not sure what to think. In the concrete building I'm in right now I range from -96 to -101 dBm and 6 asu on hspa. The GS3 next to me is getting -94 to -98 in the exact same spot and 47 asu on LTE. The weird thing is that his status bar shows 4 bars most of the time while mine is usually 2.
Is the Nexus 4 worse than normal for an hspa phone inside large buildings?
Sent from my Nexus 4 using Tapatalk 2

More info with pics
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As you can see if I hold the phone in the awkward top half of the phone manner I'm getting normal reception. If I nestled it normally in my palm, I take a hit in signal of full 2 bars. I've been repeating this all day for the last 2 days in different indoor locations and even different cities and it has never changed not even once. The n4 antenna placement makes this happen. Which is troublesome because we normally hold our phones this way while tapping and surfing with our right.
Sent from my Nexus 4 using Tapatalk 2

well.. It was the same with my one x .. Showed full bars where another device showed 2 although signal strength is the same. It is just the way they coded it to be. Let's say nexus has 90-95 set to 3 bars. Galaxy s 3, can have 90-95 display as 4..
Sent from my Nexus 4 using xda app-developers app

shadehh said:
well.. It was the same with my one x .. Showed full bars where another device showed 2 although signal strength is the same. It is just the way they coded it to be. Let's say nexus has 90-95 set to 3 bars. Galaxy s 3, can have 90-95 display as 4.
Sent from my Nexus 4 using xda app-developers app
Click to expand...
Click to collapse
My OP shows that I was watching dBm numbers, the pics above also explained the consistently repeated behavior
I think the reason this hasn't been too widely reported like the old iPhone 4 antennagate is simply the smaller volume of sold devices. The issue is nearly identical, both units also are glass construction. I don't know if the iPhone 4 placed the antenna in the same spot though
Sent from my Nexus 4 using Tapatalk 2

omnius1 said:
My OP shows that I was watching dBm numbers, the pics above also explained the consistently repeated behavior
I think the reason this hasn't been too widely reported like the old iPhone 4 antennagate is simply the smaller volume of sold devices. The issue is nearly identical, both units also are glass construction. I don't know if the iPhone 4 placed the antenna in the same spot though
Sent from my Nexus 4 using Tapatalk 2
Click to expand...
Click to collapse
Your not talking huge numbers here but +/- 3 dBm which is statistically an insignificant difference. You're looking at a 2 or 3 percent drop which could just be random. If you were seeing a drop in 10-20 dBm consistently I would say maybe there was a problem. As far as comparing LTE to HSPA they are not the same thing so why even add them to the debate. LTE is known to have far superior building penetration to anything else out there.
---------- Post added at 09:49 AM ---------- Previous post was at 09:13 AM ----------
When I first got this phone I also had a Verizon HTC Rezound on LTE. The LTE signal I got in my house ran from -75 dBm to -101 dBm, it would fluctuate depending upon conditions but usually sat around -95 dBm give or take 10%. My Nexus 4 on AT&T HSPA fluctuates between -90 and -110 dBm and usually sits around -100, again about a 10% fluctuation. Not much different than Verizons LTE signal but its to be expected as it is not true 4G. The fluctuations in signal strength are just the nature of wireless signals not the phone. Solar radiation, the weather, trees or any other obstacles between the tower and my house all affect it and all change at any given time.

Sprint S4 battery life way better than Verizon S4

I have a Sprint Galaxy S4 and my girlfriend has a Verizon Galaxy S4, and over the last year or more we have noticed there is always a huge difference in battery life -- mine lasts somewhere between 2X and 4X longer than hers.
I know of two differences between our phones, but I'm not sure which one accounts for the discrepancy.
The first is, of course, that she's on Verizon and I'm on Sprint. I have noticed that she gets 4G LTE about 95% of the time, while I get 4G LTE probably 25% of the time. If 4G uses more power, that might explain it. I also know Verizon and Sprint use very different spectrum bands, so perhaps Sprint's uses less power.
The second difference is, I have always run custom ROM's that have Caller IQ removed, while she has always left her phone stock (getting over-the-air updates). I have heard it claimed that the Caller IQ and other carrier nonsense slows down your phone and hurts battery life, but I wouldn't have imagined the effect on battery life would be so dramatic.

Nerva said:
I have a Sprint Galaxy S4 and my girlfriend has a Verizon Galaxy S4, and over the last year or more we have noticed there is always a huge difference in battery life -- mine lasts somewhere between 2X and 4X longer than hers.
I know of two differences between our phones, but I'm not sure which one accounts for the discrepancy.
The first is, of course, that she's on Verizon and I'm on Sprint. I have noticed that she gets 4G LTE about 95% of the time, while I get 4G LTE probably 25% of the time. If 4G uses more power, that might explain it. I also know Verizon and Sprint use very different spectrum bands, so perhaps Sprint's uses less power.
The second difference is, I have always run custom ROM's that have Caller IQ removed, while she has always left her phone stock (getting over-the-air updates). I have heard it claimed that the Caller IQ and other carrier nonsense slows down your phone and hurts battery life, but I wouldn't have imagined the effect on battery life would be so dramatic.
Click to expand...
Click to collapse
It's most likely the fact that you're ROM'd and rooted. Custom ROMs have a ton of benefits. LTE usually uses about the same amount of power as 3G, I can't speak for the different bands, but many other people that I know that have Verizon S4 have said the same thing. They can barely get 8 hours out of it. I get around 20 on average (unless I'm in a gaming binge).
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Nerva said:
I have a Sprint Galaxy S4 and my girlfriend has a Verizon Galaxy S4, and over the last year or more we have noticed there is always a huge difference in battery life -- mine lasts somewhere between 2X and 4X longer than hers.
I know of two differences between our phones, but I'm not sure which one accounts for the discrepancy.
The first is, of course, that she's on Verizon and I'm on Sprint. I have noticed that she gets 4G LTE about 95% of the time, while I get 4G LTE probably 25% of the time. If 4G uses more power, that might explain it. I also know Verizon and Sprint use very different spectrum bands, so perhaps Sprint's uses less power.
The second difference is, I have always run custom ROM's that have Caller IQ removed, while she has always left her phone stock (getting over-the-air updates). I have heard it claimed that the Caller IQ and other carrier nonsense slows down your phone and hurts battery life, but I wouldn't have imagined the effect on battery life would be so dramatic.
Click to expand...
Click to collapse
You cannot compare how long your battery lasts against hers unless you are comparing screen on time, actual usage. If she spends 2 hours on Facebook or something, has brightness all the way up, has screen timeout set twice as long than yours....all these things affect battery life.

Actually, the overwhelming amount of usage is "Android System" or "Android OS" or something like that, I forget which. That's what jumped out at me -- my phone almost always has "screen" as the top power user, but "screen" is never at the top of her list. I always suspected it was Caller IQ or something like that, but I don't know if CIQ is used by Verizon.

KennyG123 said:
You cannot compare how long your battery lasts against hers unless you are comparing screen on time, actual usage. If she spends 2 hours on Facebook or something, has brightness all the way up, has screen timeout set twice as long than yours....all these things affect battery life.
Click to expand...
Click to collapse
But I can say
I have had it with missed calls and texts on Sprint and moved to Verizon last month. Over 2 years on Sprint I never had a problem making it through the day even with heavy usage. Since moving to Verizon e.g. this morning, in 2 hours I am down 25 %. I turned off my phone last night, and restarted it before bed.
Also Charge time on a Verizon phone is very long especially not using a samsung charger. I can swap batteries with my spring phone and charge on any charger much faster.
I have attempted to kill ANY programs I can find that are not used, When I go back to app manager at the end of the day all kinds of things are restarted, but pulling virtually no cpu or screen time.
Granted since all units were forced to 5.0.1 even the Sprint phone lost some battery life, but not as much as switching to Verizon.
(USAGE HABITS HAVE NOT CHANGED BETWEEN PROVIDERS)

Z5 Speed Variations

So I ordered 2 Z5's from Amazon (2 different sellers); one green and one white to see which color I'd prefer. Now that I have both, quality is equal (and great!) and I like both colors, so decided to dig deeper.
There are some differences in the 2 devices. They are clearly built for different regions as the white one came in a Spectre 007 package and uses the LTE symbol for LTE and the green one came in a standard Sony package, included a QCH10 charger and shows 4G for LTE speeds. (For reference I know that 4G = LTE). The white one is Rev1 and the green is Rev4.
Here is interesting part. I've setup and configured both phones to be completely identical from brightness to apps to theme, etc. When I run a speed test using the exact same SIM card, I get way different numbers.
Running 2 consecutive tests in each on T-Mobile band 4 with the phone on my desk in the exact same position, the white one (Rev1) gives me 82.38 Down/4.71 Up and 47.55 Down/3.52 Up. The green one (Rev4) gives me 94.83 Down/8.56 Up and 97.10 Down/4.81 Up.
On WiFi, they are consistent.
Running both Antutu and Quadrant on both devices is also interesting. Antutu scores virtually the same on each; the white (Rev1) at 56k and the green (Rev4) at 55k. However, on Quadrant, the white (Rev1) is 29k and the green (Rev4) is 22k.
So what I'm looking for are comments/thoughts from some of you senior folks on the differences to help me decide on which device to keep.
Thanks!!

Since you have gone through all the trouble to set both if them up, I would run a bigger sample size of speed tests, say at least 10. I think you would see things average out and be fairly equal. Only thing is, not sure how your data plan is configured. Running network speed test in bunches chews data.

You actually ordered unboxed and used 2 different devices just because you couldn't pick which color you like before sending back the one you don't want?
I know that you 'can' but...
Sent from my E6653

This post made me rerun Antutu 64-bit today on my black E6653 Rev3 where I got 55,092 only last night, same as OP.
Well, the latest result is 62,511
So, any of you guys notice the phone is faster during the day than at night?
Screenshots of Antutu results, phone uptime is 72 hours so no reboots between runs.
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i merely get 50k on black rev4. it shows lte though..

ricodredd said:
This post made me rerun Antutu 64-bit today on my black E6653 Rev3 where I got 55,092 only last night, same as OP.
Well, the latest result is 62,511
So, any of you guys notice the phone is faster during the day than at night?
Screenshots of Antutu results, phone uptime is 72 hours so no reboots between runs.
View attachment 3534281 View attachment 3534282
Click to expand...
Click to collapse
Might depend on signal from carrier and how stable it is. Many apps and system modules launch during different conditions taking a toll on battery and perfomance for a moment. For example changing connectivity from 3G/4G to WiFi will launch several apps that will then be closed down as RAM is needed for other apps that you have launched (these apps might be in standby but do some work from time to time or just when initially launched). This due to them being set by respective app to start when connectivity changes happen. So bench them in airplane mode and with wifi off. Restart before benching.

Mine shows to be slower than the z4 lol

@EQ2000
We all know benches can vary from run to run. My point about 55K vs 62.5K on my Z5 is that OP shouldn't be using benchmark results to choose between two "identical" phones.

ricodredd said:
@EQ2000
We all know benches can vary from run to run. My point about 55K vs 62.5K on my Z5 is that OP shouldn't be using benchmark results to choose between two "identical" phones.
Click to expand...
Click to collapse
Agreed unless this indicates one phone is throttling due to inadequate application of thermal paste and/or contact between SoC and heatsink.

OP (me) isn't using benchmarks to decide. My questions (and title) were around speed variations between the 2 devices and the benchmarks were just a secondary observation.
I was just curious if it could be possible that Rev1 and Rev4 have different radios.
My apologies if the benchmarks became the root of this discussion.

One more observation today. The green Rev4 has a VoLTE button in the Quick Access drop down and the white Rev1 does not.

Improve signal strength?

Hi is there any way to boost signal strength? Out of all the flagship phones and mid range phones i have ever had the s7 edge has to be the worst. Previous phones: Z5 Premium, C5 Ultra, S6 Edge Plus, Z3, Nexus 6, HTC m8, Note 2, 3 and 4. The best was the Nexus 6. Its got that bad i feel like ditching the s7 edge for a mid range phone. I love everything else about it and it destroys the competition. But this most important factor prevents it from being the ultimate phone. any ideas welcome. I'm on BTU UK firmware and i've tried 3UK firmware and that's even worse. I've tried just using 3g only instead of 3g/lte. Factory reset many times. Tried different sim cards.
Thanks

JKWR said:
Hi is there any way to boost signal strength? Out of all the flagship phones and mid range phones i have ever had the s7 edge has to be the worst. Previous phones: Z5 Premium, C5 Ultra, S6 Edge Plus, Z3, Nexus 6, HTC m8, Note 2, 3 and 4. The best was the Nexus 6. Its got that bad i feel like ditching the s7 edge for a mid range phone. I love everything else about it and it destroys the competition. But this most important factor prevents it from being the ultimate phone. any ideas welcome. I'm on BTU UK firmware and i've tried 3UK firmware and that's even worse. I've tried just using 3g only instead of 3g/lte. Factory reset many times. Tried different sim cards.
Thanks
Click to expand...
Click to collapse
Yes same issue here. I installed 'signal guard' from the app store that repairs signal, and helps but fast from a fix.
I may sell the phone and upgrade to the OnePlus3... I haven't had a Samsung for years, and omg how far have they fallen! The S7 is truly a polished turd!

I think the s7 edge has a poor signal
Sent from my SM-G935F using XDA-Developers mobile app

sielhadi said:
I think the s7 edge has a poor signal
Click to expand...
Click to collapse
Definitely... I can't understand why so many reviews recommend this phone, when it is almost useless in a lot of locations....
I'm hoping that a modem update will resolve it...

JKWR said:
Hi is there any way to boost signal strength? Out of all the flagship phones and mid range phones i have ever had the s7 edge has to be the worst. Previous phones: Z5 Premium, C5 Ultra, S6 Edge Plus, Z3, Nexus 6, HTC m8, Note 2, 3 and 4. The best was the Nexus 6. Its got that bad i feel like ditching the s7 edge for a mid range phone. I love everything else about it and it destroys the competition. But this most important factor prevents it from being the ultimate phone. any ideas welcome. I'm on BTU UK firmware and i've tried 3UK firmware and that's even worse. I've tried just using 3g only instead of 3g/lte. Factory reset many times. Tried different sim cards.
Thanks
Click to expand...
Click to collapse
I know it's a poor workaround but you can try to limitate the network to only 2G as default and upgrade to 3G/4G only when needed; for this I downloaded an app (2g/3G switcher or smth like that) taht gives me a shortcut in the notification panel in order to quick access this band switch; doing so you will also notice a small improvement in battery life due to better signal

O ditched gs7e for oneplus3 ... Im getting LTE all in my area with full bars. When i had the s7e i didn't got more than 2bars. Also having bad reception result with battery drain. Im happy with op3. Its confirmed that cm14 is on the way for us.
Sent from my ONEPLUS A3003 using XDA-Developers mobile app

lummujaj said:
O ditched gs7e for oneplus3 ... Im getting LTE all in my area with full bars. When i had the s7e i didn't got more than 2bars. Also having bad reception result with battery drain. Im happy with op3. Its confirmed that cm14 is on the way for us.
Click to expand...
Click to collapse
What's the battery like on the OP3? The one good thing about the S7 is the battery is pretty good...

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Sent from my ONEPLUS A3003
This is all stock... It can do it better with some tweaks. Also the dash charge is IDK how to describe .. AWESOME
35% battery and i put in charger.. it will take 32min to full charge..

lummujaj said:
Sent from my ONEPLUS A3003
This is all stock... It can do it better with some tweaks. Also the dash charge is IDK how to describe .. AWESOME
35% battery and i put in charger.. it will take 32min to full charge..
Click to expand...
Click to collapse
Looks good..... Have you found any major issues with bugs?
All the reviews for the OP3 are really good, but all the reviews for the S7 were good too, and they got it completely wrong!
Looks like I'll put this S7 up for sale and upgrade to the OP3..
Cheers dude..