Iphone 4- Poor Call Quality on 3g Network

Signal strength is one thing but signal quality is something else, and is much more important with digitally-encoded communications transmissions.

As an example, in the old analogue TV days (now phasing out in favour of digital in the UK), if there was interference on the signal, all you got was a somewhat snowy picture and fuzzy sound while the interference persisted, but picture and sound nonetheless. Now with digital TV you will get picture freezes and no sound if there is interference that degrades signal quality (not signal strength).

With that in mind, and also seeing that GSM uses different transmissions from 3G, it may not be your iPhone that has a problem but it is more than likely the network and the specific conditions where you are when trying to make calls - unless, of course, the problem happens everywhere across a wide range of different environments in which case it is probably the phone that is at fault.

Assuming that you've checked coverage maps for your network operator then the next stop is complain to the network. After that, get your phone checked and replaced if necessary.

We are in a marginal 3G coverage area on O2 so the experience that you describe is very familiar to us.

I'm not sure who you get service from but the O2 coverage maps are a complete work of fiction - I don't know how they get away with it. If your service provider's maps give indications in no. of bars I'd have to question their value too - without knowing how they calculate this indicator it tells you virtually nothing at all.

What's your call quality like on 3G when you're outside bs inside?

I am also using an Iphone 4 (32 GB) and after a couple of weeks of usage, the call quality has started to deteriorate drastically to a point where you cannot even hear the person on the call but it seems they are able to hear you fine.

After a call to the Apple Support, I upgraded to 4.0.1 which has still has not fixed the issue and now they are issuing me a replacement unit. After reading this post, I turned off the 3G network settings and the call quality seems to be back to normal. I will do the same test with the replacement unit and keep you posted.

I also have same problem on Vodafone in North Laine Brighton. Have just got 2nd iPhone 4 and still the same. I'm totally gutted that I keep having to turn 3G on and off throughout the day so I can make calls, surf etc. Call quality fine unless on 3G then all garbled even though full signal. Call quality on my sure signal at home which works only on 3G is fine. Can either be an inherent problem with iphone 4 or vodafone not so good in this area. Was on O2 with my iPhone 3G and never had this kind of problem. Think I'm going to buy a Vodafone PAYG sim card for my old 3G and see if same problem as this only way to find out what is the cause. I cant live with this for 2 years, so will be sending phone back if Vodafone 3G works OK on my 3G. Will post results.

Seems that there may be a fault with the cell transmitter. Check out:

http://forum.vodafone.co.uk/topic/63977-apple-iphone-3g-voice-quality-in-brighto n/page _gopid_444462&#entry444462

Have put a Vodafone PAYG Sim in my old iPhone 3g and found it has same very bad quality / garbled calls on 3G in large area of central Brighton. It is not the iPhone 4 that is at fault. If anyone else is having this problem in Brighton please post a reply to this Vodafone forum thread so can get this issue some attention:
http://forum.vodafone.co.uk/topic/63977-apple-iphone-3g-voice-quality-in-brighto n/page _gopid_444462&#entry444462

I am experiencing the same poor call quality on the 3G network. I began searching this forum looking for answers and came across this post. After reading, I turned off the 3G on my phone, placed a test call, and the sound quality improved dramatically.

Hopefully Apple will address this with a software patch that somehow fixes this problem. I too don't want to have to manually turn off the 3G every time I want to make a phone call.

I have experienced the same thing in a couple of places. In other places the 3G service is great. This leads me to think it is network related rather than iPhone hardware.

It seems to be that the issue is the capacity of the network. Sometimes when I am very close to a tower and the signal strength is great, the call quality is poor. Other times, I can make great calls out in the boonies with one or two bars. I have also experienced good and poor call quality at the same place but different times of day.

Hmmmmm

I have the same problem in Poland. Look here please: http://discussions.apple.com/message.jspa?messageID=12048627#12048627

Same problem in Lagos, Nigeria!.....calling is fine once 3g is off. Surely there must be a way to resolve this...someone please figure it out, please!!!

....ios 4.3 solves the problem!! updated a couple of weeks ago and very significant improvements. In fact I cant notice the problem anymore...Such a relief