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LTE frequencies and ROMS

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mahanddeem
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Flash an international S5 rom then flash a t-mobile radio.
 
fffft
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Quote:
Originally Posted by mastarpete
Quote:
Originally Posted by rtwhtever
Wondering if band 12 LTE access can be added through a modem upgrade...?

More than likely, No.
Based on what I've read in other articles there is "physical" gap between the bands on 700mhz which requires filters on the PCB....

I'd say more than likely, yes.

Your information about SAW filters being necessary is out of date. The S5 has been reported to use the Qualcomm WTR1625L RF transceiver. This chipset is capable of operating on all LTE bands.

There may still be cost saving or protectionist measures in supporting hardware choices that limit us but given the available evidence, the overwhelming chances are that each variant can access an arbritrary set of LTE frequences and that the restrictions will be firmware based.

.
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mastarpete
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I'd say more than likely, yes.

Your information about SAW filters being necessary is out of date. The S5 has been reported to use the Qualcomm WTR1625L RF transceiver. This chipset is capable of operating on all LTE bands.

There may still be cost saving or protectionist measures in supporting hardware choices that limit us but given the available evidence, the overwhelming chances are that each variant can access an arbritrary set of LTE frequences and that the restrictions will be firmware based.

.
I stand corrected if that's the chipset used. I knew Samsung had been using SDRs I just was not aware that chips had become available to also dynamically handle the filtering.

Here's hoping it gets resubmitted to the FCC for band 12 approval later this year.
 
fffft
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(Last edited by fffft; 18th June 2014 at 06:42 PM.)
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I stand corrected if that's the chipset used.

Chipworks says that is the chipset and they should certainly know. The WTR1625L is release 10 compliant so it supports all 34 announced bands, not just the current bands in use. The companion WFR1620 chip in the photo is used for carrier aggregation which is LTE channel bonding to achieve higher speeds. Interestingly, Qualcomm's aggressive release schedule already puts a 28 nm successor on the table, the WTR3925 which will be the first single chip carrier aggregation solution to market. It will be release 11 compliant.

The move away from discrete filtering and aggressive push towards single IC systems is meant to capture a larger market share in this multi billion dollar market. Single chip solutions can hit cost and power reduction goals that discrete components could not reach.

The wild card, the possible hardware bottleneck will be the Avago RF front end. It's rumoured to be release 10 compliant as well, but since Avago only releases their specs and datasheets to qualified customers we can't be certain yet.
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Chas10
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Originally Posted by fffft View Post
Chipworks says that is the chipset and they should certainly know. The WTR1625L is release 10 compliant so it supports all 34 announced bands, not just the current bands in use. The companion WFR1620 chip in the photo is used for carrier aggregation which is LTE channel bonding to achieve higher speeds. Interestingly, Qualcomm's aggressive release schedule already puts a 28 nm successor on the table, the WTR3925 which will be the first single chip carrier aggregation solution to market. It will be release 11 compliant.

The move away from discrete filtering and aggressive push towards single IC systems is meant to capture a larger market share in this multi billion dollar market. Single chip solutions can hit cost and power reduction goals that discrete components could not reach.

The wild card, the possible hardware bottleneck will be the Avago RF front end. It's rumoured to be release 10 compliant as well, but since Avago only releases their specs and datasheets to qualified customers we can't be certain yet.
IFixit found a Qualcomm WTR1625L within when they did their teardown.
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Ylo
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[QUOTE]
Quote:
Originally Posted by mastarpete View Post
I stand corrected if that's the chipset used. I knew Samsung had been using SDRs I just was not aware that chips had become available to also dynamically handle the filtering.
Gentlemen, all phones operating in full duplex mode require band-specific RF duplexers to separate the uplink and downlink frequencies and route the antenna to and from the receiver and transmit PA respectively. These are essentially paired RF filters. Duplexers serve the additional purpose of blocking out of band interferers including harmonics generated by the phone transmitting on other bands. Additional SAW and BAW filters are still required in the receive chain in some cases to block interference as well.

E-UTRA bands 1 through 32 are FDD bands and require duplexers. B12 requires its own duplexer. A tunable duplexer that can operate over several of the 700 MHz E-UTRA bands might be possible in the future, but for now a phone that can operate in LTE mode on AT&T (B17), Verizon (B13), US Cellular etc.(B12) requires multiple duplexers.

A phone operating in "All LTE bands" would require an unworkable number of duplexers. As a result, LTE phones are operator and region specific with respect to LTE, and right now it takes at least three SKUs to cover the main population regions and LTE operators across the world. The radio chipset is the same, but not the duplexers and usually not the RF power amps. Some phones will not operate on the right frequencies for LTE on some carrier networks without hardware changes.
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rtwhtever
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[QUOTE=Ylo;54164230]
Quote:

Gentlemen, all phones operating in full duplex mode require band-specific RF duplexers to separate the uplink and downlink frequencies and route the antenna to and from the receiver and transmit PA respectively. These are essentially paired RF filters. Duplexers serve the additional purpose of blocking out of band interferers including harmonics generated by the phone transmitting on other bands. Additional SAW and BAW filters are still required in the receive chain in some cases to block interference as well.

E-UTRA bands 1 through 32 are FDD bands and require duplexers. B12 requires its own duplexer. A tunable duplexer that can operate over several of the 700 MHz E-UTRA bands might be possible in the future, but for now a phone that can operate in LTE mode on AT&T (B17), Verizon (B13), US Cellular etc.(B12) requires multiple duplexers.

A phone operating in "All LTE bands" would require an unworkable number of duplexers. As a result, LTE phones are operator and region specific with respect to LTE, and right now it takes at least three SKUs to cover the main population regions and LTE operators across the world. The radio chipset is the same, but not the duplexers and usually not the RF power amps. Some phones will not operate on the right frequencies for LTE on some carrier networks without hardware changes.
Interesting, thanks for sharing.
 
mastarpete
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(Last edited by mastarpete; 19th July 2014 at 10:05 AM.) Reason: added link
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[QUOTE=Ylo;54164230]
Quote:

Gentlemen, all phones operating in full duplex mode require band-specific RF duplexers to separate the uplink and downlink frequencies and route the antenna to and from the receiver and transmit PA respectively. These are essentially paired RF filters. Duplexers serve the additional purpose of blocking out of band interferers including harmonics generated by the phone transmitting on other bands. Additional SAW and BAW filters are still required in the receive chain in some cases to block interference as well.

E-UTRA bands 1 through 32 are FDD bands and require duplexers. B12 requires its own duplexer. A tunable duplexer that can operate over several of the 700 MHz E-UTRA bands might be possible in the future, but for now a phone that can operate in LTE mode on AT&T (B17), Verizon (B13), US Cellular etc.(B12) requires multiple duplexers.

A phone operating in "All LTE bands" would require an unworkable number of duplexers. As a result, LTE phones are operator and region specific with respect to LTE, and right now it takes at least three SKUs to cover the main population regions and LTE operators across the world. The radio chipset is the same, but not the duplexers and usually not the RF power amps. Some phones will not operate on the right frequencies for LTE on some carrier networks without hardware changes.
Thanks for the response.

When I google the WTR1625L the results I'm seeing are claiming it is Release 10 based and supports all announced bands. Maybe their wording is over simplifying but it seems to imply it's capable of handling the duplexing, antenna switching and basic filtering as one combined chipset.
I understand that there could still be a possibility of needing additional interference filtering.

Are you pointing out that the WTR1625L really only has selective support based on how the OEM builds out the chipset?
ie. Hardware wise (ignoring software configuration), if the OEM using the WTR1625L gets a request to not include (or doesn't ask for) a specific band they wont actually physically assemble it in a way that supports all bands.

Edit: here's a link to the press release from when the WTR1625L was announced.
http://www.multivu.com/mnr/60452-qua...mobile-devices
 
fffft
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The observations about discrete components being a limiting factor was accurate five years ago. It largely out of date now and specifically has little relevance to the specific chipset under discussion. This chipset is release 10 compliant and only requires minimal external hardware support.

A RF front end is still required, but as the current generation of Avago chips have made comparable advances and are also R10 compliant. The days when we needed a slew of SAW filters and other discrete components are behind us.

Between that and general manufacturing practice, it is all but certain that the in situ chipset can support all existing GSM and LTE bands. The (artificial) restrictions will be in the firmware.

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