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Google Pulls Support For CDMA Devices
An anonymous reader writes "Google has just made some interesting changes to their developer pages. As of today, all of the documentation, source code, and firmware images pertaining to CDMA Android devices (including the Verizon Galaxy Nexus) have been removed. A statement from Google explains that the proprietary software required to make these devices fully functional got in the way of Android's open source nature, so CDMA devices are no longer supported as developer hardware. What does this mean for the Galaxy Nexus, which is only available as CDMA in the U.S.?"
The Galaxy Nexus will continue to work just fine on CDMA. For future models, well, that's another story... Google forces the industry to either open up their firmware or move on to GSM. Good thing, IMO.
How widespread is the use of CDMA in the first place?
That depends what you mean. The old 2G GSM is TDMA (time division multiple access), whereas the modern 3G UMTS used in most of the world is CDMA - Code division multiple access.
Fortunately TFA refers to a particular CDMA implementation used in the US (CDMA2000), and not the much more common UMTS version, or CDMA in general.
And only for some features. Consumer phones will of course still be fully supported, receive all updates etc.
AOSP builds from source have never had full telephony function for CDMA devices due to missing carrier binaries, so Google is moving to clarify this, and is no longer listing CDMA devices as fully supported for developers.
Why would anyone engrave "Elbereth"?
Come on, America, at least move onto GSM. Now that it's all being ripped out and replaced with 3G there's a lot of GSM hardware on the second-hand market. It's not even expensive.
You do know that the 3G you are referring to is also known as Wideband CDMA or W-CDMA, right?
'The tyrant will always find pretext for his tyranny.' - Aesop's Fables
In Japan, they also have W-CDMA (UMTS), but at least the phones there typically use uSIM cards, which just happen to be similar to GSM SIM cards.
I can take any unlocked phone that supports UMTS, and put in any uSIM card from any other the 3 major carriers (softbank, au, & docomo) and it will work.
However in the USA, CMDA based carriers refused to allow any type of uSIM support for their networks, since they want users to be locked down to their networks. Even if you paid the extra $$$ for an unlocked iPhone 4S, you cannot get it work on both Sprint and Verizon the networks. The iPhone unlock is only for GSM not CDMA in the USA. The same is also true for Android phones as well.
I am very happy to see Google finally stand up against the horrible CMDA situation in the USA. As previous commenters have stated, it would be nice if either CMDA went away, or they followed the example of Japan, and are required to have uSIM cards.
The goal should be to have every unlocked smart-phone unlocked and able to work with every carrier, but simply inserting a SIM/uSIM card. Personally I think it is horrible that smart-phones are not required to be unlocked, since these phones are typically not subsidized with 2-3 year contacts that covers the full cost of the phone many times over.
3G just means 3rd generation. So while W-CDMA is a 3rd generation network technology, it does not mean that all 3rd generation technology is W-CDMA.
Google is just handing over Verizon's & Sprint's customer bases over to Apple, Microsoft and others?
Good Thing you added a question mark because this doesn't mean Google is handing anything over to anyone. Google and Carriers are still more then welcome to use CDMA technology all they like and are free to do anything they want with the phones as long as all the licensing requirements of all the software they use are met. Google removing CDMA from the developer pages is not the same thing as Google saying that the android license and therefor anyone using the android software is now restricted from using CDMA and it can no longer be used because that is not what it means. It means Google is having issues complying with certain licenses by posting the CDMA specs online and therefor they have simply taken it out of the open space where anyone in the world is now able to access it but carriers like Verizon and Sprint and Manufacturers like Samsung, HTC, LG, etc, etc will have no problem obtaining the resources and permissions to develop and implement the CDMA functionality and I'm willing to bet that Google will not only make it easy to load this functionality in a modular way which will ease integration but I also bet that will be aiding with the design and development to these companies to make sure it's done. Don't misinterpret Google taking CDMA from the open developer pages as meaning anything even close to saying Google is not going to allow CDMA on Android phones anymore because one example I can think of already is Sprint, a CDMA provider, has the contract to deploy Galaxy Nexus phones as soon as the exclusivity rights for Verizon finish. People shouldn't jump to conclusions so quickly based on a gross over simplification of what is actually being said without taken a moment to read it thoroughly and make an effort to understand the real implications of the actions. Hope this answers your question.
Google isn't "Dropping" CDMA support. CDMA Android phones aren't going anywhere any time soon - they're just not supporting them as DEVELOPER devices. Due to issues with Custom ROMs not working as best they could (due to the proprietary components required), Google is basically saying that the CDMA Nexus phones are no better than any other non-nexus device when it comes to "official" developer support. They'll still exist, they'll still be sold, updated, etc. but they won't be classed as "Developer devices". That's it.
This isn't anything new, it was the same case with the Nexus S 4G and even the Xoom.
+1 IDisagreeSoHeMustBeATrollOrAnAstroturferOrAShill
Storing contact info on the SIM is best treated as a secondary, legacy function. For any more complicated set of personal data you're better off exporting it in some standard-ish format your new phone can handle, or syncing it via some external service. Also, at least all the HTC Android phones I've seen seem to have no difficulty pulling the data from other devices via Bluetooth.
Being able to switch providers or phones by moving SIMs is worth even inputting the contact data manually, imo.
> and it's the "rest of the world" that decides to develop something intentionally incompatible, for no good reason. Witness ATSC versus DVB.
Rubbish. On both counts.
GSM was in development in the late 1980s, by a range of European telecom companies, and was first deployed in 1991. CDMA was developed by one American company (Qualcomm), and was first deployed in 1995. American network operators picked CDMA partly because it's American, and partly because it was slightly better than GSM in rural areas, where you have large areas with very low population density. Cost cutting, basically - it allowed them to have better coverage while having fewer towers. Not a problem in Europe, though.
Australia had a CDMA network until fairly recently, mostly for rural areas. The operator killed it when they depolyed their 3G GSM-based network because the 3G version of GSM does not have that advantage. It's quite possible to replace a CDMA network with a 3G GSM one - after all, all the phones are by definition provided on contract, and you're generally providing new phones every few years anyway. It's just that no American network chose to do so.
If I had to guess, a lot of that would be because of SIM cards, and the fact that you can use pretty much any phone on a GSM network. I doubt they're preferring CDMA to prevent international roaming.
As for ATSC... It was in development first, yes, but only slightly. However, DVB systems were deployed long before equivalent ATSC systems. At best, it's a wash. You could argue that Europe should have adopted ATSC instead, but in practice DVB systems were in use before ATSC was even finalized.
It's used in the US, where they are 20 years behind the rest of the world in mobile phones.
Come on, America, at least move onto GSM. Now that it's all being ripped out and replaced with 3G there's a lot of GSM hardware on the second-hand market. It's not even expensive.
But CDMA has at least one major advantage: When your phone rings, it does not destroy any recordings being made in the same room (the way a GSM cell phone does).
According to Wikipedia (and its cited sources), the 4G spec was finalized in 2008, and would require the ability for sustained data rates of 100Mbps. Current networks don't meet that, but LTE-Advanced could, and is only a firmware upgrade removed from current LTE systems.
Links: http://en.wikipedia.org/wiki/4G#Requirements and http://en.wikipedia.org/wiki/IMT_Advanced
Sig? What's that? Oh, 'signature'...and it's supposed to be witty? Right...
CDMA was the first technology to enable "reuse 1" deployment.
In a GSM network, you need to use several frequencies to deploy one layer of the network, so that a cell doesn't interfere with a close cell. Using 7 frequencies for example allows a cell and all its immediate neighbor cells (using an hexagonal paving) to have different frequencies. Then the the closest cell with the same frequency is not adjacent but one hop further, and its interference is reduced.
In a CDMA network, all cells in a layer can use the same frequency. Now a mobile close to its cell where the signal is high is fine, but a mobile far from its cell and hence close to another neighbor cell will suffer interference. But this can be mitigated. In CDMA the bandwidth is split between codes, and neighbor can share the code space without trampling on each other feet and creating undue interference. There's still interference at the edge, and for a give frequency the cell capacity is lower than in GSM. But now you could use the 7 frequencies of GSM to provide 7 layers instead of a single one. And you gain in total capacity. In other words, reuse 1 reduce the capacity for a single frequency, but allows maximizing the usage of each frequency, and maximizing the network capacity. That's what got every operator so excited.
This being said, CDMA as deployed in CDMA2000/EVDO networks is now pretty backward and expansive. That's why all US CDMA operators are so eager to move to LTE and leave it behind. HSPA+ is much better, and what is amusing is that it kind of move away from the CDMA tenets to introduce back TDM principles (GSM is TDM based). HSPA+ is still CDMA based, but instead of transmitting over a few codes for a long time (as initially done with CDMA), it transmits for a short duration and use most codes. And multiplexing is done over time (as in TDM). Because it turns out that this is most efficient.
Anyway, you can safely ignore fanboys of either GSM or CDMA. It's our past. The future is now and is OFDMA, as used first by WiMAX and now LTE. It also allows for reuse 1 deployments, but instead of handling allocation based on time only (GSM), or on time and codes (CDMA), it handles allocations based on frequency and time. The bandwidth is split in many small carriers (15 kHz spacing in LTE for example). Carriers are groups in bunches (a resource block in LTE is 12 carriers for example). And you allocate several RBs to a device for a subframe of 1 ms. Allocation can change each subframe.
What's the gain of OFDMA? Better handling of multipath. When you're cell phone receive the signal from the base station, it actually receives a "main path" and several echoes due to reflexions on buildings, etc. Also, the higher the bandwidth the shortest the elementary symbol duration. At some point, a symbol becomes mixed with echoes from other symbols and decoding becomes a mess. With OFDMA, become each channel is low bandwitdh (15 kHz, compared to 5 MHz for 3G for example) the symbol duration is very long. There's no problem handling with echoes, become the time delay is very small compared to the OFDM symbol duration. The price to pay for this is doing a FFT over the bandwidth to recover all the basic carriers. That's up to 2k FFT. It's doable and practical now thanks to Moore law.
That should give you a quick overview. And to the experts: please forgive the necessary simplifications to fit in a few paragraphs.