I’m still irritated about the LTE iPads being carrier specific. Looking at what public information has been let out here and there, there’s nothing I can discern that really makes me feel a lot better. Let me explain:
The baseband is most likely the Qualcomm MDM9615. This 28nm processor supports LTE (FDD and TDD), DC-HSPA+, (assuming 1xRTT up to…) EV-DO Rev-B and TD-SCDMA. Essentially most 3G + LTE technologies on one floor plan. Interesting to me is that Qualcomm also points out they have Qualcomm’s Interference Cancellation & Equalization (Q-ICE) algorithm implemented. So no challenges there.
Next, the RF front end (RFFE) or RF interface , the 65nm Qualcomm WTR1605L is a single wafer with a radio transceiver with multi-mode (LTE FDD, LTE TDD, CDMA, WCDMA, TD-SCDMA, GSM, GPS/GLONASS) and multi-band support. Piecing through the various Apple specs, Qualcomm PRs, etc… the bands supported are: GPS, PCS, AWS (Band 4), Lower (Band 12/17) /Upper 700MHz (Band 13) and Cellular (Band 5.) What is unclear is if this revision support for PCS is Band 2 only or includes the G Block as Band 25. Sprint is deploying in Band 25 so this is important. I am going to hazard a guess here, this is a SVLTE capable architecture, it seems to be SVDO capable from the specs. I don’t know if the WTR1605L is dual transceiver or you need to have a 2nd WTR1605L. I suspect it’s dual transceiver, either way Band 13 and Band 17 don’t seem to require anything separate. So there’s enough here to have a voice path too! OK, we don’t explicitly need that so there is enough with the MDM9615 or MDM9625 (It’s shipping NOW!) + WTR1605 to solve the problem of consolidating the design to a single design fits all (but Sprint.)
The long and short of it is there seems to be no physical reason why Verizon (Band 13) and ATT (Band 17) need to be in different iPad SKUs. Is this problem caused by Qualcomm, perhaps not coming clean on their specs at the behest of the operators? Is this problem caused by Apple in collusion with the operators?
Our world should have a single SKU for iPad supporting all networks, thus allowing us to purchase a single unit which further gives us the flexibility to switch providers over time (I’m ok with contract fees etc…the carriers can trade a subsidy for a penalty.) Heck, why not allow us to tether to this and use it as a hotspot in a pinch. It’s not like I’m going to power up my iPad and leave it in a fixed location for along time to provide WiFi for more than a pinch of time. Furthermore, why not allow me to subscribe to multiple carrier LTE networks so I can switch to the best one in the area, I may be willing to pay them both or all for that privilege.
It’s not clear who is causing this situation but this is serious BS my fellow consumer!! At the worst case, there should only be 2 SKU’s, a Sprint model and rest of world only until Qualcomm revises its WTR1605L to support Band 25 for Sprint.
Of course The New iPad is a data only device, thus the RF plumbing is sufficient with the MSM9615 for VZW/ATT support. Assuming Qualcomm updates the WTR1605 to support band 25, then nothing substantially new except a new HW spin will get you to ATT/Sprint/VZW single iPad. If this doesn’t happen in a timely fashion or Apple is willing to invest another $10-$15/unit, they could add other manufacturer parts such as the Fujitsu’s MB86L11A. This little beast of a transceiver is only 6.6×6.6mm and does most of what the WTR1605 does with the inclusion of Band 25 and others. This is not that hard. The $10 or so of increased cost could be offset with fewer SKUs while the power could be controlled just as effectively so there is not any showstoppers why this isn’t a viable solution to the Band 25 issue.
For the curious, the Fujitsu MB86L11A data sheet is here.
Now, for the icing on the cake, if Apple was able to score the MSM9625 they would also support Clear (TDD-LTE) and China Mobile (TD-SCDMA/TDD LTE.) Since Qualcomm is shipping this part now there is no need to do anything radical. What this all means is that with a revision to the WTR1605 or different RFFE such as the Fujitsu MB86L11A and plus the MSM6225 instead of the MSM6215, Apple could have a truly single world iPad for the rest of us.
Note regarding iPhone: mostly the same comments apply! It’s 2012, only need 1 device! Since it’s voice device and CDMA needs SVLTE, then I would add a 2nd transceiver. Since takes more cash, more space, more heat and more battery, I would take a serious look at using their Apple modded Cortex processor instead to create a soft transceiver and put some RF HW in front of it first. They have it off the shelf to begin with, secondly they could add RF chains for things like using DUAL polarized diversity antenna in the devices to give us a better user experience (higher rates, fewer drops) to differentiate their premium products. If that’s too tall of an order, then look to other OEM SDR parts second and lastly the tried and true approach of discreet HW as above for the iPad.
Ok NOW that’s it. I’m done fixing the broken.