What is TD-SCDMA?


Many hot new Chinese phones are launching as TD-SCDMA models here in China, but what does that mean for you? What is TD-SCDMA, should you buy a TD-SCDMA phone, will it work on your network? Everything you need to know here!

What is TD-SCDMA

TD-SCDMA is the 3G standard developed for and used by China Mobile on the Chinese mainland. When 3G was just beginning in China, China Mobile decided to develop their own format of 3G so to avoid paying highly expensive patent fees.

TD-SCDMA launched in China on 7th July, 2009. TD-SCDMA phones come with a dual-band mode, the main band running 3G and the backup (legacy) band being GSM.

What does TD-SCDMA stand-for?

TD-SCDMA stands for ‘time division synchronous code division multiple access’

Will TD-SCDMA work in my country?

The simple answer is β€˜No’. If you want to use 3G a 3G data connection and you do not live in China, then TD-SCDMA will not work. However, if you do not require 3G and only rely on 2G/GSM networks and Wi-Fi then a TD-SCDMA phone should happily work on most GSM frequencies meaning you can make calls, send SMS and browse the web at EDGE speed (slow download and surfing).

Should I buy a TD-SCDMA phone?

China Mobile are the largest phone network in the world based on the number of subscribers. However, this means that even here in China their 3G network is under a lot of stress and is not as reliable than China Unicom’s WCDMA option.

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The only time we would recommend buying a China Mobile TD-SCDMA phone is if you really want to have the latest handsets as they launch, as many manufacturers will launch their new device on China Mobile first.

For all other users who need 3G to work in China or Internationally, we suggest you to buy a WCDMA model which may also be known as a China Unicom version.

Do you have any questions about TD-SCDMA?

If you have any questions comments or tips regarding TD-SCMDA phones then please feel free to leave the m in the comments section below.

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55 Comments

  1. defcomk
    December 16, 2013

    Awesome Stuff More of this what is

  2. zaikatanox
    December 16, 2013

    Andi, have you had first-hand experience with TD-SCDMA? I know it’s slower than Unicom’s WCDMA, but how bad is it really? Some numbers on Speed Test would be nice if possible obviously πŸ™‚

    • Konged
      December 16, 2013

      Hi, TD-SCDMA is certainly not as fast as WCMDA/HSPA+ as it is really more closer to a previous generation of 3G. Remember when 3G started and effectively 384 Kbps was a standard. Well its really based on that. Since then WCDMA speeds have gone up a lot more while TD-SCDMA has improved a bit but nowhere near HSPA+ like speeds.

      Typical Unicom WCDMA speeds probably around 5-10mbps at least probably above 2mbps? Whilst CM’s TD-SCDMA when its fast probably not more than 2mbps so its 3G technically but not the fast 3.7xG that some of us have become accustomed to. Zol.com.cn have done loads of benchmark tests and confirms CM’s TD-SCDMA falls below 1mbps most of the time. This is one of the reasons why CM have lost out so much to Unicom in the 3G arena because their standard was always not as mature and never really had the speed to satisfy users, they know about it and have cut their losses and concentrated on the new TD-LTE network. So they are trying to make up with 4G. Zol.com.cn have tested their LTE speeds in Zhejiang and GuangDong province. The speeds are OK. 15-30mbps depending time and location.

      • zaikatanox
        December 17, 2013

        Thanks for your reply πŸ™‚ It’s always good to get some first-hand insight of TD-SCDMA, since it’s really hard to Google non-Chinese materials regarding the matter.

        I always know that TD-SCDMA is not nearly as fast as Unicom’s WCDMA. But if it’s mostly around 500 kbps to 1 Mbps and reliably consisten, I think I can probably live with if I really have to (such as in emergency or something), and this is still much better than Edge. If you don’t mind (and if you have time), can you refer me to links where they’re doing extensive testing on the speeds? I don’t read Chinese characters, so it’s hard for me to navigate Zol.com.cn πŸ™‚

        On a side note, I was in Hong Kong this past summer, and their WCDMA was not as fast as the HSPA+ speed I am getting in Canada (I think it was about 2 or 3 Mbps normally, but not much more than that), maybe because it’s too crowded? So would you say that the mainland’s WCDMA coverage was as reliable and as fast roughly as in Hong Kong?

        Also, TD-LTE is based on the same core technology as TD-SCDMA if I’m not mistaken, If they can really maintain 15-30 Mbps real world performance, then that speed won’t be too far off compared with the kind of speed you can get from (FDD)LTE in North America.

        I heard that Japan’s Softbank’s TD-LTE connection (which is maintained by Huawei IIRC) is really fast. So unless China Mobile screw it up really bad, then coverage in China should be decent too. Obviously Japan is not China, and several large cities in China are enough to make up Japan-sized population, so it is much more challenging to provide reliable coverage in China than in Japan (or even North America).

        • Konged
          December 17, 2013

          http://mobile.zol.com.cn/405/4053123.html

          Only in Chinese but you can make it out on page 3 of the article there is a typical test on speed test on CM’s 2g, 3g td-scdma and 4g td-lte.

          As you can see its 3g is around 1.2 Mbps which is quite typical when there is a mobile data signal.

          I agree that in hong Kong the 3g signal is not as hot as they advertise. 3 Mbps is quite typical from my experience. I have occasionally seen around 10mbps with wcdma. Lte around 10-20mbps, generally I find it is also a more stable signal over a longer range. They probably overloaded their 3g networks now doing little maintenance because they just want to push you to 4g.

          Even though the test speeds showing in hong Kong and mainland aren’t miles apart you will still notice access in hong Kong feels a lot faster when you know you are going out fetching data from north america and europe. Mainland has less bandwidth going out shared by a much larger population plus firewall controls etc.

          • zaikatanox
            December 18, 2013

            Thanks a lot for the link, that sure gives a lot of insight to us in the West about the mysterious TD-SCDMA (though I needed Google to translate the site).

            It looks like that, when it’s good signal, TD-SCDMA does not seem too bad then, especially when compared with EDGE, it’s just that, with its 750 million customers (twice the size of United States), the network gets clogged from time to time, so it’s kind of understandable. At least we know China Unicom seems to provide good data connections for 3G (though their user base is much smaller than China Mobile).

            And I’m glad to see that TD-LTE is performing well during trial runs. At least in principle, unlike TD-SCDMA, TD-LTE has similar theoretical performance as FDD-LTE, and in Japan (with SoftBank), TD-LTE is performing really well. Japan, obviously, is much smaller than China in population and areas, but it is still encouraging to hear such news πŸ™‚

            • NorskeDiv
              April 22, 2014

              When I was last in China I tried using both a TD-SCDMA phone and WCDMA, the TD-SCDMA phone tended to drop data connections much more frequently, especially if you are in a moving vehicle.

              TD-LTE is a totally different standard, don’t let the talk about it being an evolution of TD-SCDMA scare you off, that’s just a face saving ploy so people don’t realize the entire development of TD-SCDMA was a dead end boondoggle.

              If I were you I’d look into getting a dual mode phone that supports both LTE standards as well as WCDMA. Skip TD-SCDMA unless you enjoy torturing yourself or want to become suicidal (surfing the net using TD-SCDMA on a train in China is enough to make you want to murder someone).

        • Konged
          December 17, 2013

          mobile.zol.com.cn/405/4053123.html

          Only in Chinese but you can make it out on page 3 of the article there is a typical test on speed test on CM’s 2g, 3g td-scdma and 4g td-lte.

          As you can see its 3g is around 1.2 Mbps which is quite typical when there is a mobile data signal.

          I agree that in hong Kong the 3g signal is not as hot as they advertise. 3 Mbps is quite typical from my experience. I have occasionally seen around 10mbps with wcdma. Lte around 10-20mbps, generally I find it is also a more stable signal over a longer range. They probably overloaded their 3g networks now doing little maintenance because they just want to push you to 4g.

          Even though the test speeds showing in hong Kong and mainland aren’t miles apart you will still notice access in hong Kong feels a lot faster when you know you are going out fetching data from north america and europe. Mainland has less bandwidth going out shared by a much larger population plus firewall controls etc.

        • Konged
          December 18, 2013

          Tried posting a link but gizchina won’t pass moderator and reply never shown.

          It was only in Chinese. You can go on zol.com.cn and simply do a search with English term 3g vs 4g in the search box and many articles of benmark tests will be shown.

          There is a typical test on speed test on CM’s 2g, 3g td-scdma and 4g td-lte.

          You will see its 3g is around 1.2 Mbps which is quite typical when there is a mobile data signal.

          I agree that in hong Kong the 3g signal is not as hot as they advertise. 3 Mbps is quite typical from my experience. I have occasionally seen around 10mbps with wcdma. Lte around 10-20mbps, generally I find it is also a more stable signal over a longer range. They probably overloaded their 3g networks now doing little maintenance because they just want to push you to 4g.

          Even though the test speeds showing in hong Kong and mainland aren’t miles apart you will still notice access in hong Kong feels a lot faster when you know you are going out fetching data from north america and europe. Mainland has less bandwidth going out shared by a much larger population plus firewall controls etc.

    • December 17, 2013

      I am about to receive an N1 which is TD only. I’ll borrow a TD card and give it a go πŸ™‚

      • zaikatanox
        December 17, 2013

        Thanks, Andi πŸ™‚ I don’t understand why you would need to order the TD version of N1 though. Wasn’t the N1 already made available for the US and Europe? Why couldn’t you just get the WCDMA version?

        • December 17, 2013

          In China we still don’t have the WCDMA model and I couldn’t wait any longer : D

          • Airyl
            December 17, 2013

            Xiaomi is probably regretting their decision of delaying the S800 model now. That thing is far overdue.

            • Dragon
              December 17, 2013

              It’s actually Qualcomm’s fault. Not enough supply..

  3. Xiaolu
    December 16, 2013

    What about the China Telecom CDMA? I’m clueless, cannot see the difference (now my dual SIM holds Unicom and Telecom and I’ll leave Unicom aside for price reasons).

  4. defcomk
    December 17, 2013

    Awesome Stuff More of this what is

  5. zaikatanox
    December 17, 2013

    Andi, have you had first-hand experience with TD-SCDMA? I know it’s slower than Unicom’s WCDMA, but how bad is it really? Some numbers on Speed Test would be nice if possible obviously πŸ™‚

    • Guest
      December 17, 2013

      Hi, TD-SCDMA is certainly not as fast as WCMDA/HSPA+ as it is really more closer to a previous generation of 3G. Remember when 3G started and effectively 384 Kbps was a standard. Well its really based on that. Since then WCDMA speeds have gone up a lot more while TD-SCDMA has improved a bit but nowhere near HSPA+ like speeds.

      Typical Unicom WCDMA speeds probably around 5-10mbps at least probably above 2mbps? Whilst CM’s TD-SCDMA when its fast probably not more than 2mbps so its 3G technically but not the fast 3.7xG that some of us have become accustomed to. Zol.com.cn have done loads of benchmark tests and confirms CM’s TD-SCDMA falls below 1mbps most of the time. This is one of the reasons why CM have lost out so much to Unicom in the 3G arena because their standard was always not as mature and never really had the speed to satisfy users, they know about it and have cut their losses and concentrated on the new TD-LTE network. So they are trying to make up with 4G. Zol.com.cn have tested their LTE speeds in Zhejiang and GuangDong province. The speeds are OK. 15-30mbps depending time and location.

    • Andi Sykes
      December 17, 2013

      I am about to receive an N1 which is TD only. I’ll borrow a TD card and give it a go πŸ™‚

    • zaikatanox
      December 17, 2013

      Thanks, Andi πŸ™‚ I don’t understand why you would need to order the TD version of N1 though. Wasn’t the N1 already made available for the US and Europe? Why couldn’t you just get the WCDMA version?

    • Andi Sykes
      December 17, 2013

      In China we still don’t have the WCDMA model and I couldn’t wait any longer : D

    • zaikatanox
      December 17, 2013

      Thanks for your reply πŸ™‚ It’s always good to get some first-hand insight of TD-SCDMA, since it’s really hard to Google non-Chinese materials regarding the matter.

      I always know that TD-SCDMA is not nearly as fast as Unicom’s WCDMA. But if it’s mostly around 500 kbps to 1 Mbps and reliably consisten, I think I can probably live with if I really have to (such as in emergency or something), and this is still much better than Edge. If you don’t mind (and if you have time), can you refer me to links where they’re doing extensive testing on the speeds? I don’t read Chinese characters, so it’s hard for me to navigate Zol.com.cn πŸ™‚

      On a side note, I was in Hong Kong this past summer, and their WCDMA was not as fast as the HSPA+ speed I am getting in Canada (I think it was about 2 or 3 Mbps normally, but not much more than that), maybe because it’s too crowded? So would you say that the mainland’s WCDMA coverage was as reliable and as fast roughly as in Hong Kong?

      Also, TD-LTE is based on the same core technology as TD-SCDMA if I’m not mistaken, If they can really maintain 15-30 Mbps real world performance, then that speed won’t be too far off compared with the kind of speed you can get from (FDD)LTE in North America.

      I heard that Japan’s Softbank’s TD-LTE connection (which is maintained by Huawei IIRC) is really fast. So unless China Mobile screw it up really bad, then coverage in China should be decent too. Obviously Japan is not China, and several large cities in China are enough to make up Japan-sized population, so it is much more challenging to provide reliable coverage in China than in Japan (or even North America).

    • Guest
      December 17, 2013

      Xiaomi is probably regretting their decision of delaying the S800 model now. That thing is far overdue.

    • Guest
      December 17, 2013

      It’s actually Qualcomm’s fault. Not enough supply..

    • Guest
      December 17, 2013

      http://mobile.zol.com.cn/405/4053123.html

      Only in Chinese but you can make it out on page 3 of the article there is a typical test on speed test on CM’s 2g, 3g td-scdma and 4g td-lte.

      As you can see its 3g is around 1.2 Mbps which is quite typical when there is a mobile data signal.

      I agree that in hong Kong the 3g signal is not as hot as they advertise. 3 Mbps is quite typical from my experience. I have occasionally seen around 10mbps with wcdma. Lte around 10-20mbps, generally I find it is also a more stable signal over a longer range. They probably overloaded their 3g networks now doing little maintenance because they just want to push you to 4g.

      Even though the test speeds showing in hong Kong and mainland aren’t miles apart you will still notice access in hong Kong feels a lot faster when you know you are going out fetching data from north america and europe. Mainland has less bandwidth going out shared by a much larger population plus firewall controls etc.

    • Guest
      December 17, 2013

      mobile.zol.com.cn/405/4053123.html

      Only in Chinese but you can make it out on page 3 of the article there is a typical test on speed test on CM’s 2g, 3g td-scdma and 4g td-lte.

      As you can see its 3g is around 1.2 Mbps which is quite typical when there is a mobile data signal.

      I agree that in hong Kong the 3g signal is not as hot as they advertise. 3 Mbps is quite typical from my experience. I have occasionally seen around 10mbps with wcdma. Lte around 10-20mbps, generally I find it is also a more stable signal over a longer range. They probably overloaded their 3g networks now doing little maintenance because they just want to push you to 4g.

      Even though the test speeds showing in hong Kong and mainland aren’t miles apart you will still notice access in hong Kong feels a lot faster when you know you are going out fetching data from north america and europe. Mainland has less bandwidth going out shared by a much larger population plus firewall controls etc.

    • Guest
      December 18, 2013

      Tried posting a link but gizchina won’t pass moderator and reply never shown.

      It was only in Chinese. You can go on zol.com.cn and simply do a search with English term 3g vs 4g in the search box and many articles of benmark tests will be shown.

      There is a typical test on speed test on CM’s 2g, 3g td-scdma and 4g td-lte.

      You will see its 3g is around 1.2 Mbps which is quite typical when there is a mobile data signal.

      I agree that in hong Kong the 3g signal is not as hot as they advertise. 3 Mbps is quite typical from my experience. I have occasionally seen around 10mbps with wcdma. Lte around 10-20mbps, generally I find it is also a more stable signal over a longer range. They probably overloaded their 3g networks now doing little maintenance because they just want to push you to 4g.

      Even though the test speeds showing in hong Kong and mainland aren’t miles apart you will still notice access in hong Kong feels a lot faster when you know you are going out fetching data from north america and europe. Mainland has less bandwidth going out shared by a much larger population plus firewall controls etc.

    • zaikatanox
      December 18, 2013

      Thanks a lot for the link, that sure gives a lot of insight to us in the West about the mysterious TD-SCDMA (though I needed Google to translate the site).

      It looks like that, when it’s good signal, TD-SCDMA does not seem too bad then, especially when compared with EDGE, it’s just that, with its 750 million customers (twice the size of United States), the network gets clogged from time to time, so it’s kind of understandable. At least we know China Unicom seems to provide good data connections for 3G (though their user base is much smaller than China Mobile).

      And I’m glad to see that TD-LTE is performing well during trial runs. At least in principle, unlike TD-SCDMA, TD-LTE has similar theoretical performance as FDD-LTE, and in Japan (with SoftBank), TD-LTE is performing really well. Japan, obviously, is much smaller than China in population and areas, but it is still encouraging to hear such news πŸ™‚

    • NorskeDiv
      April 22, 2014

      When I was last in China I tried using both a TD-SCDMA phone and WCDMA, the TD-SCDMA phone tended to drop data connections much more frequently, especially if you are in a moving vehicle.

      TD-LTE is a totally different standard, don’t let the talk about it being an evolution of TD-SCDMA scare you off, that’s just a face saving ploy so people don’t realize the entire development of TD-SCDMA was a dead end boondoggle.

      If I were you I’d look into getting a dual mode phone that supports both LTE standards as well as WCDMA. Skip TD-SCDMA unless you enjoy torturing yourself or want to become suicidal (surfing the net using TD-SCDMA on a train in China is enough to make you want to murder someone).

  6. Xiaolu
    December 17, 2013

    What about the China Telecom CDMA? I’m clueless, cannot see the difference (now my dual SIM holds Unicom and Telecom and I’ll leave Unicom aside for price reasons).

  7. February 25, 2014

    “as many manufacturers will launch their new device on China Mobile first.”
    Are you kidding me?

  8. Shindo
    February 25, 2014

    “as many manufacturers will launch their new device on China Mobile first.”
    Are you kidding me?

  9. Aaron
    May 22, 2014

    If I buy a HTC phone with Mobile 3G GSM / TD-SCDM
    can i use it in Australia and other gsm using coutries ?
    And what is HTC M8T ?

  10. Aaron
    May 22, 2014

    If I buy a HTC phone with Mobile 3G GSM / TD-SCDM
    can i use it in Australia and other gsm using coutries ?
    And what is HTC M8T ?

  11. Vijay
    June 3, 2014

    Hi if i bought Unicom version of WCDMA Xiaomi phones… Can i use it in india without unlocking it???? Plz answer me …

    • Roey
      February 24, 2016

      yes

  12. Vijay
    June 3, 2014

    Hi if i bought Unicom version of WCDMA Xiaomi phones… Can i use it in india without unlocking it???? Plz answer me …

    • Guest
      February 24, 2016

      yes

  13. sri
    September 21, 2014

    i want clear detail about TD-SCDMA

  14. Guest
    September 21, 2014

    i want clear detail about TD-SCDMA

  15. Crystal
    October 2, 2014

    Hi there, I’m not so sure if anyone can help me. I am in a very big dilemma. I recent got a phone from China in Guangzhou. It’s the Sugar Phone made by France. I was in China during May and I saw this phone and decided to pop in my SIM card. A Canadian Bell network sim. I turned on the phone and received a message welcoming me to China and that I can use networks there to roam. I normally get these messages when I turn off airplane mode, which means my SIM card and network is working right? Problem is I did not buy the phone at the time I was there. Now fast forward, last month, I decided to ask my dad who was in China to purchase that same phone in different colour so I can use it here. But when I finally open it, it does not work. I tried to change the networks and all the settings and nothing works. I am stuck and I’m worry this phone has become a waste and I cannot have it become a waste because I am scared my dad will yell at me. But I know for a fact it worked in China. Now is there a reason why in China Bell network was able to connect and roam but when I’m here it’s not reading my SIM card? It’s the same SIM card. Or is because the phone is actually still locked? If anyone can help me that would be amazing, I can’t bring the phone back to China and my dad thinks its a major hassle to wait for him to go back to China and get it fixed and then bring it back. Please if anyone can answer me, I really appreciate it. Thank you!

    • Leo P
      March 21, 2015

      Try it on Rogers or Fido as bell dont have 2G/EDGE service in Canada

  16. Crystal
    October 2, 2014

    Hi there, I’m not so sure if anyone can help me. I am in a very big dilemma. I recent got a phone from China in Guangzhou. It’s the Sugar Phone made by France. I was in China during May and I saw this phone and decided to pop in my SIM card. A Canadian Bell network sim. I turned on the phone and received a message welcoming me to China and that I can use networks there to roam. I normally get these messages when I turn off airplane mode, which means my SIM card and network is working right? Problem is I did not buy the phone at the time I was there. Now fast forward, last month, I decided to ask my dad who was in China to purchase that same phone in different colour so I can use it here. But when I finally open it, it does not work. I tried to change the networks and all the settings and nothing works. I am stuck and I’m worry this phone has become a waste and I cannot have it become a waste because I am scared my dad will yell at me. But I know for a fact it worked in China. Now is there a reason why in China Bell network was able to connect and roam but when I’m here it’s not reading my SIM card? It’s the same SIM card. Or is because the phone is actually still locked? If anyone can help me that would be amazing, I can’t bring the phone back to China and my dad thinks its a major hassle to wait for him to go back to China and get it fixed and then bring it back. Please if anyone can answer me, I really appreciate it. Thank you!

    • Leo P
      March 21, 2015

      Try it on Rogers or Fido as bell dont have 2G/EDGE service in Canada

  17. angel
    November 21, 2014

    would LTE FDD work in india ?

  18. Guest
    November 21, 2014

    would LTE FDD work in india ?

  19. Trish
    February 4, 2015

    i bought a motorola xt907 from china with the promise this will work on Australian networks. It worked for a couple of calls then all numbers i called after this were changed to overseas numbers with overseas charges. Can i modify this phone to work on Australian networks? I have a 4G sim

  20. Trish
    February 4, 2015

    i bought a motorola xt907 from china with the promise this will work on Australian networks. It worked for a couple of calls then all numbers i called after this were changed to overseas numbers with overseas charges. Can i modify this phone to work on Australian networks? I have a 4G sim

  21. Steve
    November 24, 2015

    Hi bought 2 x scdma phones very cheap in China (30.00 each) thought they may work in uk – they do not tried giff gaff 02 2g sims – “the current network does not comply with this unit standard” is displayed – is there a cure or do I just bin ! Seems a shame all apps and music ect works without sim.

  22. Steve
    November 24, 2015

    Hi bought 2 x scdma phones very cheap in China (30.00 each) thought they may work in uk – they do not tried giff gaff 02 2g sims – “the current network does not comply with this unit standard” is displayed – is there a cure or do I just bin ! Seems a shame all apps and music ect works without sim.

  23. Governor John Tarus - China
    January 2, 2016

    Nice article, my problem and question I have always had with TD-SCDMA ans WCDMA is no answered clearly. I have been wondering my nice TD-SCDMA phone I bought in China cannot work in Kenya. Thanks for the clarification Andi.

  24. Governor John Tarus - China
    January 3, 2016

    Nice article, my problem and question I have always had with TD-SCDMA ans WCDMA is now answered clearly. I have been wondering why my nice TD-SCDMA phone I bought in China cannot work in Kenya. Thanks for the clarification Andi.

  25. Roey
    February 24, 2016

    Hi, Do you know why on dual band systems like Samsung Note 5 the TD-SCDMA tends to drop so often and use 2G? It apears it is much more sensitive than the other network by China Unicom which alwas stays on 3G no matter what.

  26. Guest
    February 24, 2016

    Hi, Do you know why on dual band systems like Samsung Note 5 the TD-SCDMA tends to drop so often and use 2G? It apears it is much more sensitive than the other network by China Unicom which alwas stays on 3G no matter what.

  27. rasha18
    April 23, 2018

    Hi. I m using TETC U5 a 4G LTE Phone. But it’s not working in Pakistan. How to change it from 2G to 4G. Please guide