LTE / TD-LTE Compatibility

[MacinJosh]

4ringsnbr and WiWavelength - thanks for the help understanding - this is not my area of expertise.

 

The reason why I am so curious is because apple tries very hard to limit the number of devices they have on the market.

 

I am curious how many different models of the next iPhone they are going to have to make to meet the needs of wireless carriers in the US and across the globe.

 

How many bands/antennas do you think they will be able to cram into the next iPhone?

 

The at&t iPhone will be easy as all they have to do is add LTE compatibility, and the same for the Verizon one. As for the Sprint one, there might or might not be LTE 800 compatibility, and maybe by freak chance LTE 2500/2600 for Clearwire. And from what I understand, all over the world will be different bands of LTE, thereby making this all the more confusing. The only thing common between all iPhones could be the GSM/EDGE/W-CDMA quad-band compatibility that is seen in the iPhone 4S. My head is spinning from the confusion. :puke:

[WiWavelength]

The at&t iPhone will be easy as all they have to do is add LTE compatibility, and the same for the Verizon one.

 

Josh, how will adding LTE capability to the iPhone be "easy"? An LTE iPhone will have to retain all of the GSM/W-CDMA/CDMA1X/EV-DO connectivity of the iPhone 4S plus add 2x2 MIMO LTE 750 antennas for VZW and/or 2x2 MIMO LTE 700/2100+1700 antennas for AT&T. Even if Apple does two LTE models, a la the "new" iPad, it must do so in a phone approximately one seventh the volume of the iPad. Again, how is that "easy"?

 

As for Sprint iPhone LTE compatibility, I would wager a guess that it will be limited to LTE 1900. And, if the iPhone 4S is any indication, it also will not support CDMA1X 800. And that could be a good thing, as it would confine the throngs of iPhonerds to CDMA1X/EV-DO/LTE 1900, leaving more CDMA1X/LTE 800 and/or TD-LTE 2600 capacity free for other users.

 

AJ

[MacinJosh]

Josh, how will adding LTE capability to the iPhone be "easy"? An LTE iPhone will have to retain all of the GSM/W-CDMA/CDMA1X/EV-DO connectivity of the iPhone 4S plus add 2x2 MIMO LTE 750 antennas for VZW and/or 2x2 MIMO LTE 700/2100+1700 antennas for AT&T. Even if Apple does two LTE models, a la the "new" iPad, it must do so in a phone approximately one seventh the volume of the iPad. Again, how is that "easy"?

 

As for Sprint iPhone LTE compatibility, I would wager a guess that it will be limited to LTE 1900. And, if the iPhone 4S is any indication, it also will not support CDMA1X 800. And that could be a good thing, as it would confine the throngs of iPhonerds to CDMA1X/EV-DO/LTE 1900, leaving more CDMA1X/LTE 800 and/or TD-LTE 2600 capacity free for other users.

 

AJ

 

It would be easier since the new iPad is already at&t & Verizon LTE compatible. And I hope that the Sprint version will have 1x on 800 for the 1xA voice quality at the least, even if it doesn't have LTE 800. And if I had better WiMax service in my home, I would use my Shift just as much as I used my iPhone.

[WiWavelength]

It would be easier since the new iPad is already at&t & Verizon LTE compatible.

 

Nope. You cannot overlook the size difference. The iPad is a 9.7 in tablet -- not an apt parallel for the iPhone. For example, that a Toyota Tundra can easily tow a boat does not mean that a Toyota Prius can easily tow a boat.

 

AJ

[irev210]

Josh, how will adding LTE capability to the iPhone be "easy"? An LTE iPhone will have to retain all of the GSM/W-CDMA/CDMA1X/EV-DO connectivity of the iPhone 4S plus add 2x2 MIMO LTE 750 antennas for VZW and/or 2x2 MIMO LTE 700/2100+1700 antennas for AT&T. Even if Apple does two LTE models, a la the "new" iPad, it must do so in a phone approximately one seventh the volume of the iPad. Again, how is that "easy"?

 

As for Sprint iPhone LTE compatibility, I would wager a guess that it will be limited to LTE 1900. And, if the iPhone 4S is any indication, it also will not support CDMA1X 800. And that could be a good thing, as it would confine the throngs of iPhonerds to CDMA1X/EV-DO/LTE 1900, leaving more CDMA1X/LTE 800 and/or TD-LTE 2600 capacity free for other users.

 

AJ

 

I wonder how much carrier nit-picking is involved in all this. I would assume VZN would be upset if AT&T got AWS support but VZN got left out (granted AT&T absolutely needs AWS whereas VZN does not).

 

I would also think that Sprint would be anxious to get the new iPhone onto 800 to improve voice coverage and dropped calls. I would assume sprint would really want to see that on the iPhone so they can keep PCS spectrum open for refarming. More iPhones on 1x @ 1900 means less space to refarm, right?

 

I am just starting to think if Apple will bite the bullet and start engineering iPhones to have the same PCB but have a modular antenna system that they could just drop in during assembly.

[pyroscott]

Nope. You cannot overlook the size difference. The iPad is a 9.7 in tablet -- not an apt parallel for the iPhone. For example, that a Toyota Tundra can easily tow a boat does not mean that a Toyota Prius can easily tow a boat.

 

AJ

 

I didn't know Toyota Tundra's could haul a boat. I kid, I kid.

 

I'm thinking that Apple won't want to go too crazy on supporting all of Sprint's various bands. They need to give iPhonerds another big reason to buy the next iPhone the following year, 800 LTE. Then the year after, 2600 LTE.

[WiWavelength]

I wonder how much carrier nit-picking is involved in all this. I would assume VZN would be upset if AT&T got AWS support but VZN got left out (granted AT&T absolutely needs AWS whereas VZN does not).

 

Actually, neither "needs" AWS 2100+1700 MHz capability. VZW currently holds AWS across only the eastern half of the US and will wait for the SpectrumCo-Cox AWS transaction to shake out before VZW does anything in AWS. And AT&T, while it has released all of its LTE devices thus far with AWS, quite possibly will never deploy anything in AWS. AT&T's AWS holdings have always been overstated. Now, after assigning much of that AWS to T-Mobile as part of the merger break up fee, AT&T has downright little AWS left in the top markets. See my graph:

 

 

 

 

AJ

[irev210]

Actually, neither "needs" AWS 2100+1700 MHz capability. VZW currently holds AWS across only the eastern half of the US and will wait for the SpectrumCo-Cox AWS transaction to shake out before VZW does anything in AWS. And AT&T, while it has released all of its LTE devices thus far with AWS, quite possibly will never deploy anything in AWS. AT&T's AWS holdings have always been overstated. Now, after assigning much of that AWS to T-Mobile as part of the merger break up fee, AT&T has downright little AWS left in the top markets. See my graph:

 

 

 

 

AJ

 

That makes a lot of sense - thank you for all the info!

 

I wonder if the antenna situation is one of the reasons why there have been rumors that the new iPhone will sport a 4" display.

 

If you had to predict how apple would configure the new iPhone - do you think it would follow in the footsteps of the new iPad?

[MacinJosh]

Nope. You cannot overlook the size difference. The iPad is a 9.7 in tablet -- not an apt parallel for the iPhone. For example, that a Toyota Tundra can easily tow a boat does not mean that a Toyota Prius can easily tow a boat.

 

AJ

 

Ok. I see what you mean. Hopefully they can make the LTE antenna's smaller by the time the next iPhone comes out.

[4ringsnbr]

Ok. I see what you mean. Hopefully they can make the LTE antenna's smaller by the time the next iPhone comes out.

 

The length of the antenna and the spacing between receive antennas on LTE for the Rx MIMO are dictated by the frequency used (actually by the wavelength). The wavelength is calculated as the speed of light divided by the frequency; therefore, the higher the frequency, the shorter the wavelength (thus, smaller antenna and less space between MIMO elements). For 750 LTE, the wavelength is about 15.75 inches. A quarter wavelength will be used between the MIMO elements, so approximately 3.94 inches will have to separate the two receive antennas for 750 LTE. This means the AT&T and Verizon iPhones (two different models) will have to be bigger than the current device to fit the antenna array properly. If they do AWS and/or PCS LTE, the spacing requirement is less than half that much. This is why Verizon is looking for AWS to use LTE in the upcoming VoLTE only flip phones-- much smaller antennas for much smaller phones.

[4ringsnbr]

It would be easier since the new iPad is already at&t & Verizon LTE compatible. And I hope that the Sprint version will have 1x on 800 for the 1xA voice quality at the least, even if it doesn't have LTE 800. And if I had better WiMax service in my home, I would use my Shift just as much as I used my iPhone.

The voice quality using 1xAdvanced carriers will be the same on PCS 1900 as well as ESMR 800. NV will replace all 1xRTT equipment with 1xA in both frequencies. As long as you have better than -105 dBm signal on PCS, your voice quality will be great.

[MacinJosh]

The voice quality using 1xAdvanced carriers will be the same on PCS 1900 as well as ESMR 800. NV will replace all 1xRTT equipment with 1xA in both frequencies. As long as you have better than -105 dBm signal on PCS, your voice quality will be great.

 

Unless NV significantly improves the signal quality in Pahrump, then I won't be getting good voice quality at home.

[4ringsnbr]

Unless NV significantly improves the signal quality in Pahrump, then I won't be getting good voice quality at home.

Could be worse-- you could be with AT&T or another GSM carrier and have horrible voice quality even with a great signal...

[MacinJosh]

Could be worse-- you could be with AT&T or another GSM carrier and have horrible voice quality even with a great signal...

 

My voice quality wasn't too bad with at&t actually. It was the weak 3g signal in my house that caused my phone to drop constantly to EDGE and the increasing number of dropped calls that was occurring.