VoLTE is a battery killer

[bigsnake49]

Nothing earthshaking, but confirming out worst fears:

 

Every mobile carrier wants to replace their old voice services with new VoIP-based systems utilizing their 4G networks, but it looks like they’ve got some big kinks to iron out in the technology first. Wireless testing and measurement vendor Spirent Communications has identified a big problem with voice over LTE (VoLTE): it consumes twice as much power as a traditional 2G call, which could have big implications for mobile phone battery life.

Metrico Wireless, a radio field testing company Spirent acquired in September, conducted voice trials on a commercial VoLTE-enabled network in two U.S. cities, comparing the power consumption of VoIP calls made over LTE against the power used by the same carrier’s CDMA systems. Spirent-Metrico didn’t name the carrier, but it’s not hard to guess.

MetroPCS is the only U.S. operator with a live VoLTE service and a commercially available handset. The 1540 milliamp hour (mAh)-battery on Metro’s sole VoLTE handset, the LG Connect 4G, also lines up with the battery capacity of the device Spirent tested.

The results of those tests should give carriers and consumers pause. The average power consumption for a 10-minute CDMA circuit-switched call was 680 milliwatts (mW) while the average consumption for a VoLTE call of the same duration was 1358 mW. That’s double the power drain. Spirent estimated that on a full charge, its test smartphone could support 502.6 minutes of talk time using CDMA only, but the same charge would only deliver 251.8 minutes of talk time using VoIP on the 4G network. And that’s with all other data communications turned off.

 

http://gigaom.com/mo...2g-voice-calls/

 

The good news is if you're using LTE data and VOLTE at the same time, then it is more energy efficient than using CDMA voice and LTE since it requires two separate radio paths.

[miguell2]

Any idea why this might be? I am guessing with time this will even out since the tech is so new. LTE-Advanced might have built-in advantages as well. I really don't know, what does everyone think?

[WiWavelength]

Any idea why this might be? I am guessing with time this will even out since the tech is so new. LTE-Advanced might have built-in advantages as well. I really don't know, what does everyone think?

 

LTE Advanced will be worse because it switches the uplink to OFDMA, which has a greater peak to average power ratio. I will be happy to have someone rebut this assertion, but there is no good reason to use LTE Advanced for voice.

 

AJ

[iansltx]

I've got a reason to use LTE-A for voice: if you're in a good signal area, you're transmitting for less time because the modulation is higher. i.e. your cell has more capacity. If a carrier is using AMR-HR to skimp on...er...conserve capacity then they might do this as well.

 

As far as VoLTE battery life is concerned, these days voice isn't what people are using their phones for, so chances are they'll run their battery down from something other than voice calls anyway, VoLTE or not. Not that I'm excusing subpar battery performance, but I am stating a fact for smartphone users (which VoLTE users will be for the next year or two).

 

I'm also curious about how much battery life WCDMA voice uses as compared to GSM or CDMA. I'll bet there's just as much difference as between VoLTE and CDMA, despite the fact that we're comparing two circuit-switched techs, versus one circuit-switched and one packet-switched. The difference is probably even more marked if you rewind to 2007, when WCDMA was a relatively new technology.

[S4GRU]

With how much talking I do on the phone, the battery issue is no big deal to me. The biggest issue for me about VoLTE would be coverage.

 

Robert via Nexus 4 using Tapatalk 2

 

 

[DaQue]

Hehehehe... All those phones and you don't talk on them much.

[WiWavelength]

Hehehehe... All those phones and you don't talk on them much.

 

Not a phone, it is a "handset" or "device."

 

 

AJ

[S4GRU]

Hehehehe... All those phones and you don't talk on them much.

 

I despise talking on the phone. Its awkward for me.

 

Robert via Nexus 4 using Tapatalk 2

 

 

[WiWavelength]

I've got a reason to use LTE-A for voice: if you're in a good signal area, you're transmitting for less time because the modulation is higher. i.e. your cell has more capacity. If a carrier is using AMR-HR to skimp on...er...conserve capacity then they might do this as well.

 

The so called "race to idle" does not really apply to voice, which is a synchronous transmission activity. Voice bits continue ad infinitum. LTE Advanced, using 2x2 uplink MIMO, cannot transmit those voice bits before they arrive at the radio stack. So, for modulation complexity, the lower, the better -- to ensure accurate reception.

 

AJ

[Fraydog]

The good news is you can run LTE CoMP - the LTE version of soft handover - with LTE Advanced. That may help with any dropped calls or handoff issues.

 

The other major problem is coverage. A lot more cells will be needed for VoLTE. It will be a nice technology in its prime. There are still issues to work out.

[caleuche]

 

The so called "race to idle" does not really apply to voice, which is a synchronous transmission activity. Voice bits continue ad infinitum. LTE Advanced, using 2x2 uplink MIMO, cannot transmit those voice bits before they arrive at the radio stack. So, for modulation complexity, the lower, the better -- to ensure accurate reception.

 

AJ

 

You could collect 100 ms of voice, encode it, and then transmit for 10 ms for low order modulation or 6 ms for high order and so on, then at least you wouldn't be transmitting 90-95 percent of the time. The downside of that is the power consumed in buffering and encoding probably negate the advantage of that duty cycle.

 

I imagine the codec is going to use mp3 sized frames (5000 or so samples iirc).

[DaQue]

I despise talking on the phone. Its awkward for me.

 

Robert via Nexus 4 using Tapatalk 2

 

Well you seem to excel at texting and data so it works out.

 

I use less than 100 minutes of my 450 a month. This month I may hit 200 with 30 minute hold times for the dang cable company.

[bigsnake49]

I am sure that Sprint, Verizon, AT&T and T-Mobile have already performed these tests and that's why they aren't rushing to deploy VOLTE. The only one that jumped the gun is MetroPCS. Even they will cool down once the merger goes through.

[Fraydog]

I am sure that Sprint, Verizon, AT&T and T-Mobile have already performed these tests and that's why they aren't rushing to deploy VOLTE. The only one that jumped the gun is MetroPCS. Even they will cool down once the merger goes through.

 

The MDM9625 might provide enough gains in battery life to deal with the battery concerns. I'd sacrifice some battery life for better voice quality. I know that HD Voice can be achieved on EVRC-NW but I don't know how much of a starter that technology is. Is anyone other than Sprint even using this?

[Sgt. Slaughter]

 

The MDM9625 might provide enough gains in battery life to deal with the battery concerns. I'd sacrifice some battery life for better voice quality. I know that HD Voice can be achieved on EVRC-NW but I don't know how much of a starter that technology is. Is anyone other than Sprint even using this?

 

When Sprint starts using VoLTE the MDM9625 will be a deep afterthought and there will be something vastly better.... Don't think its much to worry about now at all.

 

Sent from my EVO using Tapatalk 2

 

 

[lynyrd65]

I saw this on fiercewireless this morning

 

Operators hoping to engage in widespread deployment of voice over LTE in order to gain spectral efficiencies in their network may face some unhappy customers because one vendor's recent tests showed that VoLTE calls can slash a device's talk-time battery life by half.

The study comparing device battery life for calls placed over an LTE network vs. calls placed over a CDMA network was conducted on an unnamed U.S. operator's network in two major markets using a smartphone capable of supporting both CDMA and VoLTE voice calling. "The device's estimated battery life was reduced by 50 percent or about 252 minutes of talk time when voice calls were placed over the LTE network, compared to voice calls placed over the CDMA network," according to the study, authored by Ardeshir Ghanbarzadeh, director, services development, for Metrico Wireless, which was acquired by Spirent Communications in September.

 

Link

[irev210]

Given that CDMA is a mature technology vs. VoLTE which is not, I would suspect that battery life over the next few years will continue to improve.

 

I think it would have been interesting to compare 1x advanced with HD voice vs. volte - make it more apples to apples.

 

Either way, packet switched vs. circuit switched, hard to compare.

 

I wonder if verizon will be able to completely sunset its CDMA network by 2021 as indicated. That would be awesome.

[WiWavelength]

I think it would have been interesting to compare 1x advanced with HD voice vs. volte - make it more apples to apples.

 

That comparison would not likely change the results one iota. CDMA1X Advanced typically uses less power on the downlink -- that is is how it gains capacity and/or coverage -- and should use no more power on the uplink. And HD Voice (EVRC-NW) seems to make the impression that it requires greater throughput, but it does not. Its average voice throughput rates are essentially the same as those of EVRC, but EVRC-NW just uses a more advanced codec to squeeze more voice bandwidth into the same bit rate.

 

AJ

[Boosted20V]

Given that CDMA is a mature technology vs. VoLTE which is not, I would suspect that battery life over the next few years will continue to improve.

 

I think it would have been interesting to compare 1x advanced with HD voice vs. volte - make it more apples to apples.

 

Either way, packet switched vs. circuit switched, hard to compare.

 

I wonder if verizon will be able to completely sunset its CDMA network by 2021 as indicated. That would be awesome.

 

Out of curiousity why would it be awesome? I don't really see what there is to get excited about?

[irev210]

That comparison would not likely change the results one iota. CDMA1X Advanced typically uses less power on the downlink -- that is is how it gains capacity and/or coverage -- and should use no more power on the uplink. And HD Voice (EVRC-NW) seems to make the impression that it requires greater throughput, but it does not. Its average voice throughput rates are essentially the same as those of EVRC, but EVRC-NW just uses a more advanced codec to squeeze more voice bandwidth into the same bit rate.

 

AJ

 

I would assume the more advanced codec requires more processing power to decode.

 

Out of curiousity why would it be awesome? I don't really see what there is to get excited about?

 

More space for LTE. I would prefer if all four major networks ran LTE exclusively.

[Fraydog]

It would be nice if this test were run with more modern handsets in an area with better LTE coverage, like South Korea where active VoLTE networks are deployed. Then we can see where the true gap in battery consumption is on handsets that use 28nm basebands.

[Sgt. Slaughter]

The nm isn't gonna matter here as we are comparing the battery use from cdma to volte... The chip used in both will be the same nm.... Thus you might last longer on the 28nm but CDMA would still trump volte...

 

Sent from my EVO using Tapatalk 2

 

 

[bigsnake49]

The nm isn't gonna matter here as we are comparing the battery use from cdma to volte... The chip used in both will be the same nm.... Thus you might last longer on the 28nm but CDMA would still trump volte...

 

Sent from my EVO using Tapatalk 2

 

Just from a pure data point of view, just the fact that you're transmitting 8Kbits vs 64Kbits has some effect on the power consumption. More data usually means more power.