GSM sound, CDMA sound?

I did not know that but I guess it does good for both, the user, and the network

 

This story is a little hard for me to swallow, as given. Was the person on speakerphone or using a handsfree device? A lot of noise improvement can be achieved just by holding the microphone closer to your mouth; microphones have limited dynamic range and I really doubt that a car A/C fan would be heard with equal volume (or at all) if the GSM user had the microphone near his mouth. Speakerphone or a poor handsfree device, yea that I could understand.

As Bobo pointed out in this forum, a few posts back, noise reduction is employed,and the phone quality makes a big difference. Besides, noise cancellation technology can be handled at the phone end before entering the network. I won't comment on verizon, since I don't use it. But I do suspect that some of the noise cancellation that CDMA uses (to minimize BW) is also the cause for the poorer audio quality(or clipping) that some complain about. It is trying to very actively supress background noise and the software doesn't work so well with rather large background sounds.

 

I called my work voice mail from my cell phone this morning, from inside my car. I placed the a/c on and the fan on all 5 speed positions. Only with the very top speed position did I hear the fan in the background but as a very low hiss. And at that position, one could not say that the fan overwhelmed my voice by any means at all: my conversation was very clear and loud.

Sorry mate, I think the story is a bit off target: this is a phone/microphone problem and not related to GSM. Another urban legend.

 

What I'm saying is that you did not have control or access to all the variables with your observation (ie talking to a friend in a car, where was his a/c, or how loud was the radio?), to separate out phone issues vs GSM,CDMA, or repeat the observation. Take a look at Bobo's post #8 which has nice experiment on this topic. Mine is another. I'm also emphasizing, as others have, that the phone electronics play a major role with this. CDMA phones really like to have a cleaned up signal feed to the network to conserve spectrum, as I understand it, but that doesn't mean that GSM phones cannot use noise reduction technology in the phone too. Handicap hearing aids use them, as do some newer BT headsets.

I used no headset and the a/c was in normal direction. The candy bar phone is being used normally. I tape recorded the example and can listen to it over and over again.

You know if someone has a car radio on that is of equal amplitude at the phone microphone as your voice is, noise cancellation is not going to remove it. Even, if it were 'white' noise of the kind that my $300 Bose noise reduction headphones were meant to remove, there is a limit on the dB attenuation it can provide. I can still hear quite a bit of engine noise with the Bose headphones.

 

There's lots of variables that are being left out in Jerro's example, such as the Nokia phone model and if the phone was using EFR or AMR. We may never know for certain, but the fact is, EFR has little or no noise cancellation. EFR is still in use in many areas of the US. Another problem is the phone. Some phones (especially European phones like Nokias, Sony Ericsson and Siemens) usually overdrive the microphone' sensitivity. The Samsung x427/x246 is also another phone that seriously overdrives the microphone leaving the codec no chance to cancel noise.

One thing that must be clear is that it is the codec's responsibility to cancel any background noise. It is not the network or the phone. It is the codec. That being said, if your phone uses EFR, chances are you will pick up lots of background noise. With AMR under the same identical conditions, chances are the call will be a lot quieter.

CDMA phones, on the other hand, undergo stricter quality control and as such are far more consistent when it comes to voice quality. Though there are exceptions. I've had conversations with people using a Sprint phone (while driving a car) and I have been able to hear all their background noise, like everytime they hit rough road, their wipers going, etc. Like viewfly said, there is a limit to how much noise can be cancelled. If the microphone is too sensitive, you can hear all the noise and this depends entirely on which phone is used and the amount of noise around. If you are in an insanely loud place, there's no way the best CDMA phone is going to do magic and cancel all the noise.

Another thing that must be understood is that BOTH GSM and CDMA benefit from noise cancellation. For CDMA, noise cancellation preserves spectrum since the amount of spectrum used in a CDMA network depends on the variable amount of data pumped by the codec which is directly related to how much audio the codec sends. For GSM, noise cancellation reduces the number of time slots broadcasted by the phone. Although this doesn't save any spectrum, it reduces the overall noise floor in the area which reduces overall interference on other callers improving overall call quality, not to mention it saves your phone battery.

 

Yes, it's pretty loud here! I didn't have my phone on me and used my friend's vox8900 (good phone imo). I couldn't understand a darn thing due to warbling and the loud hiss. Echoes have been better according to my friends. Nextel is awful with echoes!

Verizon takes a good 1-3 rings before the cell phone rings here, with about a 5% call rate failure (rolling to VM). At my house though, it was more like a 50% roll to VM feature

 

I agree 100% with Bobolito. The AMR codec at the base station is very effective at increasing capacity and improving speech quality. Noise cancellation at the phone DSP can also be very effective, esp. for echo cancellation with speakerphones. Even the placement of the microphone in location to the phone antenna can help reduce a different kind of noise, the 'bubblebee' effect heard on GSM phones that get smaller and smaller in size and have RF interference getting into the phone microphone circuitry and passed to the network. And yes, if the amplitude of the voice sound wave reaching your phone's microphone from your car radio is the same amplitude as your own voice sound wave, a codec is not going to distinguish your own voice from the radio's and cancel it. This morning I could hear the audio system of car in front of me (with his and my windows closed) very well. I doubt that he could use his phone without background interference.

Jerro, I do not dispute your personal experiences, but I disagree with your general implications about 'Cingular GSM phones'. I'm not trying to start a argument with you, but I don't want WA to be responsible for starting a legend that background noise is a GSM vs CDMA thing. This is my opinion.

 

Jerro, I got interrupted before I could finish my last post, and now I've lost my 'edit' privileges. I apologized if my language seemed flip to you, perhaps it was not my best choice of words that day.

As far as my opinion to your first post, I don't really seem to be able to identify if a caller (to my landline) is GSM or CDMA.

Best,
viewfly

 

In my case, from my landline, I can SOMETIMES identify if the caller is using CDMA or GSM. It depends primarily where they are, the enviroment in their surroudings and the phone they are using. Sometimes when EVRC cancels background sounds creates artifacts and side effects to the voice. If these conditions are present, I can always tell for certain someone is using CDMA. However, sometimes the brightness and loudness of some callers tell me they are indisputably using a GSM phone.

Some cases are really confusing. I have a friend with a Nokia 6340i and whenever I talk to her, if I didn't know better, I would think she's using Verizon because of how dull she sounds. I could say the same thing about my sister in law who uses a Nokia 3595. She was driving down the Turnpike at high speed and I didn't know she was driving until she told me.

However, my sister who owns a x427, I can always tell when she's driving because the road noise is unquestionable.

We all use Cingular and drive similar cars and don't open the windows.

 

Bobolito. Knowing first hand that one must chose words carefully, I hope you don't tell your female friend that she sounds dull


Yesterday, I did a test with the radio on (normal volume in my car) and again it didn't overwhelm the voice on the phone.

I did compare the 6230 with my old Moto 720. The moto was a wee bit better at removing background sound and, more importantly, had a deeper, more bass sound to it. The nokia was brighter, and perhaps was being overdriven because I could here some distortion. I liked the moto sound better. On the receiving end, both these phones sound equal and very very good.

 

sorry i didnt reply sooner.. i couldnt find my post and didnt relise someone asked a question...

So like What about IDEN ex. Nextel

.. we went into there store and they were like after they did a credit check "Mrs.(mylastname) you have such good credit, i have never seen credit as good as yours. feel free to get almost ANY phone we have at NO COST except you have to buy 50 bucks worth of accories, we will even skip the first two payments till you are ready."

they like seemed intrested in us.. i think im going to get that widndows mobile Nextel Phone... or that mp3 one... im not sure witch.. what would u get...?????

 

I just read this article, that may help CDMA users with sound quality soon.

Qualcomm Improves 3G Sound Quality

Qualcomm says that it has integrated sound enhancement technology onto the Company's Mobile Station Modem chipsets. Designed to improve the acoustic performance of 3G mobile handsets and improve the clarity of conference and hands-free calls, the echo-canceling technology is enabled by LifeVibes Voice software from Royal Philips Electronics.

"Superior audio performance is fundamental to consumer approval and the deployment of echo-cancellation technology on Qualcomm chipsets will dramatically improve voice communications in even the noisiest environments," said Mark Frankel, vice president of product management for Qualcomm CDMA Technologies. "We are excited that our work with Philips will enable our partners to offer handsets with enhanced acoustic performance to their customers."

"LifeVibes Voice products are a pioneering technology and the result of decades of audio and acoustic research," said Cees Geel, senior director of marketing and sales for Philips Software. "The availability of LifeVibes Voice products on Qualcomm chipsets brings a new level of mobility and sound quality to mobile handset users and enriches the user experience in a very tangible way."

Echo-canceling sound enhancement technology enables users to make clear and full-duplex conference, videoconference and hands-free calls without audial interference from stationary background noise. Qualcomm will initially provide support for echo-cancellation software on Enhanced Multimedia Platform MSM6550 and MSM6275 chipsets, both of which are compatible with CDMA2000 and WCDMA networks. Additional acoustic performance improvements to remove background noise using a dual-microphone spatial filter are planned for the Convergence Platform, achieved through the integration of another LifeVibes Voice product, the Noise Void background noise eliminator.

 

I know what you mean.

But just take a minute and visit this link and look at definition number 10.

http://dictionary.reference.com/search?q=dull

 

Oh yes, I know exactly what you mean by a dull, flat sound. I hope your friend does! Just pullying your chain. I also know the correct way that 'amplitude' is used in the physics of sound!

 

Very true....I used a cheap Kyocera phone with Virgin prepaid service.(they use Sprint towers I think) It was the best sounding phone I ever used. It made me seriously think of switching to Sprint it sounded so good.

 

Exactly; it totally depends on where you are/tower usage, etc. etc. GSM and CDMA can sound just as good under the same conditions. In the middle of nowhere right next to a tower, both will often sound crystal clear.
During rush hour, one might work better at a time than the other because one network's tower in the area might not be as busy as the other carrier's.

 

I do find that T-Mobile sounds a little better than Cingular in NJ. But I think that's because Cingular sounds louder and sometimes gets distorted. However, I like the fact that Cingular sounds louder since that gives my earpiece a little more juice in case the other end is weak sounding.

By louder, I mean if I call a number connecting via T-Mobile towers the call sounds nice and clear (as long as there is good signal), but if I connect via Cingular towers (using the same phone) the same call sounds noticeably louder.

 

I believe that SprintPCS uses a lower bitrate with their codec, thereby sacrificing clarity for coverage.

 

I guess you didn't have to edit your gain table like people down here in Va, or did you just do it anyway?

 

As long as you own a Motorola, you MUST edit your gain table to get a good loud volume that works in almost any environment. Doesn't matter what the carrier is. However, this is a totally different issue than the T-Mobile vs. Cingular volume level.

 

that's an area dependent thing as well, and in my area I have to say this is Verizon.

 

All;

I know I am coming late to this discussion but I want to add another question to the mix.

Whether on CDMA or GSM is it safe to say that buying a higher end phone will nearly always provide you with a better conversation in voice quality than would a lower end model?

I don't mean to generalize to much but I am considering moving over to Cingular from Sprint and not having followed Cingular's phones to closely in the past 2 years has left me doing a lot of research in the last week.

I am considering the Razr, Slvr, Pebble, Sony W600I, ROKR. I realize not all of these phones are out for testing but just going on the question/theory that higher price equates to better quality would it be the opinion of most that I would find myself with probably the best chance at having good quality conversations with one of these models listed above?

Thanks in advance.