Qualcomm Announces MDM9x25, MDM8225 support 3GPP Rel.10, advanced Carrier Aggregationby Brian Klug on February 27, 2012 2:00 AM EST
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Paying attention to basebands is something that really has become one of our niches. So much of a smartphone's design is entirely rooted in requirements around what air interfaces it has to operate with, and there's always a delicate balancing act between the OEMs, carriers, and silicon vendors all wanting different things. If you can predict the constrains, you can largely predict the choices, and out fall the handsets themselves.
At last year's MWC, Qualcomm announced MDM9x25, the spiritual successor to MDM9x00, which we've seen in a huge number of 4G LTE devices - everything from data cards to hotspots to smartphones. Whereas MDM9x00 was a 45nm design, MDM9x25 is a 28nm design just like MDM9x15, and includes support for just about every air interface out there - CDMA2000 1x/EVDO, GSM/EDGE, TD-SCDMA, UMTS (HSPA+, DC-HSPA+), and LTE-Advanced. What it builds on from MDM9x15 is both increasing the UE Category from 3 to 4 -which connotes a corresponding boost in maximum downlink bandwidth from 100 Mbps to 150 Mbps on 20 MHz FDD, inclusion of MIMO and DC HSPA+ (two things that were previously mutually exclusive in earlier 3GPP releases) - and also being targeted at a more traditional data card or wireless hotspot application. MDM9x15 is still largely targeted for deployment on handsets running on carriers who are pushing currently for DC-HSPA+ and LTE Category 3 (both TDD and FDD).
Today, what Qualcomm is announcing are some more details about MDM9625/MDM9225 and also MDM8225. The news is simple - all three parts support 3GPP Release 10, and the carrier aggregation techniques within, including asymmetric aggregation for unpaired spectrum, and inheritance of the multi-band carrier aggregation from Release 9. You might wonder why those particular three parts would be singled out, but the reasons are simple. First, 3GPP Releases define both HSPA+ and LTE features since Release 8. Second, the two tiers remain analogous the same way MDM9x15 is analogous with MDM8215, and I would wager MDM9x00 was with MDM8220.
There are some other interesting other details I've learned about MDM9x25 as well. This will be the first part I'm aware of that will come with GNSS support for GPS, GLONASS, and Compass - the Chinese satellite navigation system. MDM9x25 will work with Qualcomm's WTR1605 transceiver and PM8019 power management IC.
The final addendum is confirmation of something I noticed while doing the Verizon 4G LTE wireless hotspot reviews. Back then, I noted that there there was no application processor for routing and network on those devices. Instead, they seemed to use the baseband for those functions entirely. MDM9x25 and MDM8225 will continue this trend by including an integrated AP tailored for these routing functions, and possibly in conjunction with a Qualcomm Atheros AR6003 or AR6004 WLAN and BT combo chip.
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apinkel - Monday, February 27, 2012 - linkI'm not sure I understand the benefits of 3GPP release 10 and carrier aggregation (which I thought was just LTE advanced... i.e. faster speeds). I'm sure you guys have your hands full right now but I'd like to see some coverage on that when you can fit it in.
name99 - Monday, February 27, 2012 - linkBasic aggregation is just using more spectrum to get more speed to one particular user. I'm not especially convinced that, in the real world, it's of value for anything more than bragging rights.
Asymmetric aggregation is more interesting and more useful. Right now in FDD systems (basically most of the world except China) you allocate say 10MHz of downlink and a matching 10MHz of uplink when you allocate spectrum. This equal allocation made sense in the days when voice traffic dominated, but is not ideal nowadays when data dominates, and most of that is download. Asymmetric aggregation is not a perfect solution to this, but it allows one to do things like, for example, tie together a 10/10MHz matched pair (up and down) with another 10Mhz somewhere else used only for down without a partner up band, so it's a step towards more efficient spectrum usage.
Basically my take on all this is that the parts of 3GPP/LTE that lead to more efficient spectrum are useful and worth cheering. The parts that lead to higher single user peak spectrum are basically a waste of time --- they will allow reviewers to make a big deal about how fast a new phone is at the time the review comes out, but pretty soon, once multiple users per cell start using those features, no-one sees that peak speed.
One exception to this is EDGE Advanced, which aggregates two (or perhaps more) of the 200kHz EDGE bands. That could be useful insofar as EDGE running under best conditions is still a lower peak speed than one might want in reasonable and realistic situations. But, of course, that assumes
(a) that the carriers are bothering to upgrade to EDGE Advanced (are they in the US?)
(b) a phone that would be smart enough to automatically switch between LTE, 3G/HSPA and EDGE depending on conditions and loading, rather than requiring the user to remember to make the switch manually when 3G/HSPA or LTE are overloaded. I'm unaware of any phone with those sorts of smarts.
apinkel - Monday, February 27, 2012 - linkThat makes sense. Thanks for the explanation.
I'm all for technology that allows carriers to efficiently use spectrum but I agree that beyond a certain point more speed is overkill. For me I'm perfectly fine with my 3Mpbs broadband connection at home and I don't really know why I'd need more than that on my phone... except bragging rights as you mentioned.
I'm in the states but I'm on a CDMA carrier in an area where GSM coverage isn't very good so I'm not familiar with how the GSM/EDGE carriers are handling things.
iwod - Monday, February 27, 2012 - linkOther Site report it also support LTE-Advance.
And this will be the first chipset to support ALL methods of carriers, ( including China's TDS-CDMA and TDD LTE ), as well as Chinese and Russia and Europe's methods of GPS.
How to get this into iPhone 5?