iPhone 5 cannot received calls when in LTE

[keithkng]

Phone model MD297ZA black 16g. carrier singtel 13.0

D*** sh*tty to have to "downgrade" to 3G in order to receive calls. I wonder if I shld complain to ST and ask for a replacement phone....

 

[edm_11]

provided its a phone issue. i also dunno if that's the case.

 

[keithkng]

Will use the phone for another 2-3 days with LTE switched off and try to confirm if problem disappears. Will keep all bros here posted...

 

[edm_11]

i've been off LTE for 4 days already. no problems with incoming calls at all. LTE is a mixed bag. Sometimes ok sometimes not ok lol

 

[DQUEK123]

Like I said before in my previous thread. I had this problem on the day 2 and I called m1 to confirm the problem, they advised me to turn off LTE when I'm not using.

I didn't take their advice seriously. So I rebooted my phone and since then I have no issue at all. Even I move around to different LTE station. Guess my iPhone 5 LTE chip might be haywire during the first 2 days. Now everything is perfect.

If you continue to have LTE issue, it might not be a network problem as I travel a lot in Singapore and I really do not have this problem on my black64gb ip5. So I guess u guys might wanna go for an exchange if the problem persists.

 

[edm_11]

how do we go about to exchange? singtel comm center? not sure if they have sets to exchange also.. dun think we can call to check right?

 

[sandwicher]

i'm not sure, but i had the impression our 3g is on wcdma, is it the same?
My Singtel Samsung S2 once i disable wcdma, no more 3g, gsm is 2g speeds only

While on the line, if emails come in, line gets cut off..


My M1 iphone4 auto switch to o after talking awhile. once on o, can only use voice or data.
Once off the line, all the data starts flowing in again

Oh yes! You're right. Our 2G uses GSM but 3G is on CDMA

But I also remember that StarHub's LTE will be using/refarming the 2G network (ie, GSM, which allows simultaneous voice and data). That's the 1800 spectrum i think? SingTel and M1 uses both 1800 and 2600? Not sure if its overlapping or will they be split 50-50%?

Either way, since 3G was on CDMA (which doesn't allow voice and data together), but we've no problems receiving calls (the iPhone switches to 2G), I don't think LTE is the problem now? Probably the telco needs to push a carrier update and fix this problem.

 

[wharzhee]

To no one in particular,

3G WCDMA aka UMTS in Singapore supports both Data & Voice.

 

[wharzhee]

LTE does not have voice over network yet. Only 3G transmits the voice. Correct me if I'm wrong but the phone should automatically switch to 3G while recieving calls and switch back after the call.

correct. after reading this entire thread, only u made the most sensible and correct conclusion.

 

[aptget]

so if we have to switch off LTE, then whats the point of having it

 

[wharzhee]

so if we have to switch off LTE, then whats the point of having it

It should have rolled back.
But to add to it, Sometimes I wonder why people lamented that the iPhone 4/4S did not have LTE. haha!

 

[cyberet]

It should have rolled back.
But to add to it, Sometimes I wonder why people lamented that the iPhone 4/4S did not have LTE. haha!

so when the phone is on LTE, any voice call comes in, it has to rollback to 3g.
this rollback process causes some calls to get rejected?
so telco issue?

 

[edm_11]

probably cos of the rollback.. wait for new carrier updates?

 

[keithkng]

Ok! Confirmed that after switching OFF LTE, no more problems receiving calls.

 

[edm_11]

lol yup. but that kinda defeats the purpose of iphone 5 lol. console myself that by doing this i get incoming calls and save on data so that i do not exceed lo. Really hope a carrier setting update will help and not related to hardware

 

[meekiatah]

My $25 Nokia phone don't have such problem.

Just kidding hor.. Hope you guys get it resolved soon.

 

[sdchew]

To no one in particular,

3G WCDMA aka UMTS in Singapore supports both Data & Voice.

Let me try to clarify; For the GSM Network Spec:

2G = GSM(Voice)
2.5G = GSM (Voice) + GPRS/EDGE (data)
3G = WCDMA(Voice) + HSPA (data)/HSPA+(data)
4G = WCMDA + LTE

The CDMA iPhone 5 is for CDMA2000 networks. You can say its the variant of WCDMA which is not part of the GSM Group's standard. Data on the CDMA2000 network is on the EVO (3G) or LTE (4G) protocol.

 

[wharzhee]

ur point being? what's with the quote?

[edit: did u read the entire thread before quoting me.]

 

[yssiang]

I'm on nano sim and have the exact same problem as yours. So I think it's not SIM card issue.

I've been having this problem too - cannot receive calls while on LTE - callers get a "subscriber is unavailable" message, and then a calleralert SMS will come in. But can make outgoing calls, send & receive SMS etc etc.

After rebooting, phone can receive calls but i think once move around and switch to different base station, problem comes back.

Switched off LTE yesterday and now problem seems to be resolved.

Am on Singtel but didnt swap for new nano-sim (cut old micro sim) - so am wondering if its a sim-card problem?

 

[DQUEK123]

Let me try to clarify; For the GSM Network Spec:

2G = GSM(Voice)
2.5G = GSM (Voice) + GPRS/EDGE (data)
3G = WCDMA(Voice) + HSPA (data)/HSPA+(data)
4G = WCMDA + LTE

The CDMA iPhone 5 is for CDMA2000 networks. You can say its the variant of WCDMA which is not part of the GSM Group's standard. Data on the CDMA2000 network is on the EVO (3G) or LTE (4G) protocol.

Bro, no need so complicated... the problem here all bros face is, when phone on LTE network, in-coming calls come in:

1. The ip5 will by right goes from LTE signal to 3G signal, this can be observed on the phone.
2. Then ip5 user can receive the call.
3. However, sometime the phone is stubborn and refuse to roll back to 3g and stay at LTE.
4. Then ip5 user cannot receive call and will receive SMS of voice-mail.

All these problem has nothing to do with LTE do not support voice over data, we all know that, this is why ip5 roll to 3G for phone call and put data on 3G speed temporary. After phone call the data speed resume to LTE.