by Andrew J. Shepherd
Sprint 4G Rollout Updates
Thursday, March 5, 2015 - 12:15 PM MST
I got my first real smartphone.
Bought it at the five and dime.
Browsed S4GRU 'til my fingers bled.
Was the summer of 6&9.
Spring has not quite yet sprung for a few more weeks. But with the annual Mobile World Congress just wrapping up today in Barcelona, new smartphones that likely will dominate the mobile landscape through most of the summer are starting to sprout. Germinating at the FCC OET (Office of Engineering and Technology) over the past few days have been authorization filings for the Sprint variants of the Samsung Galaxy S6, Samsung Galaxy S6 Edge, and HTC One M9. Get ready for the summer of 6&9.
S4GRU started a tradition of FCC OET authorization articles right around this time in 2012 with the debut of Sprint's first LTE devices. So, to celebrate the third birthday in our long running series, let us take a look at the cellular RF capabilities of this latest threesome of Samsung Galaxy and HTC One handsets.
To begin, all three devices follow what has been for the past 18 months the standard Sprint variant configuration: tri band LTE, non SVLTE, single RF path with e/CSFB. No surprises there. On top of Sprint tri band LTE, the three handsets also cover the CCA/RRPP LTE bands -- with one possible caveat for the One M9. More details on that later.
As an aside, Qualcomm is changing up its baseband modem branding and numbering schemes. Previously, branding was Gobi and numbering was, to use one example, MDM9625 for standalone modem chipsets. Then, many Snapdragon processor chipsets also included the same modems on die -- a la the Snapdragon 800, aka MSM8974, which integrated the same stack as in the standalone MDM9625. Branding is now changing universally to Snapdragon and numbering, to use just one example again, will follow the X10 LTE pattern. That last example is the Snapdragon 810's brand new LTE category 9 modem, which has no standalone modem precursor. But other rebranded and renumbered examples with their standalone precursors include the Snapdragon X5 LTE (MDM9625), Snapdragon X7 LTE (MDM9635), and Snapdragon X12 LTE (MDM9645).
That Qualcomm background is useful as we will start the rundown with the One M9, which incorporates the Snapdragon 810 with X10 LTE chipset. To cut straight to the chase, below are the tested ERP/EIRP figures:
- Band class 0: 20 dBm
- Band class 1: 25 dBm
- Band class 10: 20 dBm
- Band 2: 25 dBm
- Band 4: 23 dBm
- Band 12: 18 dBm
- Band 25: 25 dBm
- Band 26: 17 dBm
- Band 41: 23 dBm
For reference, and this will pertain to the ERP/EIRP figures cited later for the Samsung devices, too, the above figures represent our best averaged and rounded estimates of max uplink ERP/EIRP -- with uniquely Sprint frequencies receiving heavier weighting in band class 10, band 25, and band 26. Of course, the usual disclaimers about lab testing versus real world performance apply.
Now, to provide some analysis, RF output looks relatively healthy, somewhere in the better than average range. And it generally, albeit minimally trumps that of its HTC One M8 predecessor -- see our S4GRU article from last year.
The aforementioned caveat about CCA/RRPP bands is that the FCC OET filing for the One M9 does not include separate testing of band 5. Now, that may not indicate omission of band 5 -- because band 26 is a superset of all band 5 frequencies. But we cannot guarantee that the One M9 will attach to band 5 roaming networks without MFBI for band 26.
Two other omissions are worthy of note. First, the FCC OET documents offer no mention of band 41 carrier aggregation capabilities. This may or may not be cause for concern. Current carrier aggregation is downlink reception only, not uplink transmission. And FCC OET testing is just the opposite -- uplink transmission only, not downlink reception. As such, the testing is not required to include carrier aggregation. We do know that the Snapdragon 810 with X10 LTE supports up to 3x 20 MHz FDD/TDD carrier aggregation, so we expect that 2x or 3x band 41 carrier aggregation is on board. S4GRU will follow up if more info becomes available.
Second, the One M9 was not tested, thus is not authorized for domestic GSM/W-CDMA bands. Rabid phone unlockers under the new Sprint domestic unlocking policy, consider yourselves forewarned.
Finally, the One M9 docs suggest VoLTE support at launch. But Sprint has no established timeline for VoLTE, so take that with a grain of salt. It could be just a latent capability.
Moving on to the galactic federation, Samsung has split its Galaxy S6 offerings in two this year, offering a separate Galaxy S6 Edge as a step up version. With one possible exception, both Galaxy S6 handsets have the same RF capabilities. However, their ERP/EIRP figures are not identical, so they are broken out separately below:
Samsung Galaxy S6:
- Band class 0: 17 dBm
- Band class 1: 23 dBm
- Band class 10: 17 dBm
- Band 2: 22 dBm
- Band 4: 23 dBm
- Band 5: 16 dBm
- Band 12: 21-17 dBm (declining with increasing carrier bandwidth)
- Band 25: 22 dBm
- Band 26: 16 dBm
- Band 41: 16 dBm
Samsung Galaxy S6 Edge:
- Band class 0: 18 dBm
- Band class 1: 22 dBm
- Band class 10: 18 dBm
- Band 2: 22 dBm
- Band 4: 24 dBm
- Band 5: 17 dBm
- Band 12: 17 dBm
- Band 25: 22 dBm
- Band 26: 17 dBm
- Band 41: 19-11 dBm (declining with decreasing center frequency)
As for analysis, both Galaxy S6 variants are about average -- with the Galaxy S6 Edge holding generally a 1 dB "edge," pun intended. Neither, though, holds up to the tested RF output of the One M9. Some surmise that Samsung's much debated shift in handset materials this year from largely cheap feeling plastic to more premium metal and glass has had a detrimental effect on RF design and performance. We cannot jump to that conclusion, but the RF falloff does become even more apparent in comparison to last year's Samsung Galaxy S5 -- again, see our article.
In particular, band 41 EIRP is disappointing. A higher frequency band should precipitate higher RF output. But that is not the case this year, as the band 41 uplink maximum for both Samsung handsets drops 4-7 dB below that of the One M9 and fully 6-9 dB below that of the Galaxy S5.
Also, the band 41 extreme frequency differential in the Galaxy S6 Edge is disconcerting. It is up to 8 dB better in high BRS spectrum than in low EBS spectrum. Meanwhile, multiple band 41 center frequencies in BRS/EBS spectrum will vary from market to market, so performance will also vary. If using the Galaxy S6 Edge on band 41, you better hope for EARFCN 40978 or greater.
Alright, that less than good news out of the way, let us move on to more positive things. The Samsung Galaxy S6 handsets are LTE category 6 -- with explicitly noted support for 2x band 41 carrier aggregation. More on that, too, later. They also have been tested and authorized for domestic GSM/W-CDMA bands, so unlocking in the future for use on other domestic operators may be possible. VoLTE, though, is noted as not supported out of the box. It is, however, on board other Galaxy S6 variants, thus could be added later with a Class II Permissive Change filing and potentially a software update.
Now, back to LTE category 6. In addition to its material design change this year, Samsung has also broken lockstep with Qualcomm, choosing to forgo the 64 bit, octa core Snapdragon 810 processor in favor of its in house 64 bit, octa core Exynos 7420. S4GRU does not traffic in application processor chipset holy wars -- there are plenty of other sites for that. But this chipset change has other ramifications. Unlike the Snapdragon 810, the Exynos does not have a baseband modem on die. Thus, Samsung has had to include a separate modem chipset. And, unfortunately, the full identity of that modem remains a mystery. We know of another Samsung in house chipset -- the Exynos Modem 333 or SS333 -- that could provide the category 6 LTE connectivity, possibly even full 3GPP connectivity.
However, for Sprint, that still leaves lingering 3GPP2 (CDMA2000). Is it provided by a second modem, meaning a third chipset? Could it be a reappearance of the notorious VIA Telecom CDMA2000 modem? S4GRU sincerely hopes not. Or maybe Qualcomm is still on board, not in the processor, but in its aforementioned Snapdragon X7 LTE (MDM9635) category 6 LTE standalone 3GPP/3GPP2 baseband, which supports the same 2x 20 MHz FDD/TDD carrier aggregation. Time will tell.
Well, that is a wrap for this set. If you are young and restless with the Samsung Galaxy S6s and HTC One M9, will you wonder what went wrong? Or will the summer of 6&9 be the best days of your mobile life?
Discuss in the comments.
Sources: FCC, Bryan Adams