TDD LTE or FDD LTE

[T_ADD]

Hi, I have been getting into LTE stuff very recently for obvious reasons. So I'd like to ask you all a question and appreciate all the feedback/opinions I could get out of those planning to move into LTE or already have and are working with it.

I've put the question here because my present network is from Huawei.

What do you use in your network or are planning to use and WHY? - TDD or FDD LTE?

Please tell of your experience/opinions in terms of:

vendor related - what is preferred
technical/capacity advantages
UE availibility
any other points that need to be considered

Thanks and very much looking forward to it. :)

[labviewlover]

though am so busy, but i love to help:)

dear bro,
It depends on what services / service mix the operator wants to offer and
what deployment is suitable for the operators business case whether this or
the other duplex mode is more favorable than the other.

the following attached PDF (from Inacon) explains in details FDD n TDD modes..plus their spectrum use table

and their usages. ultimately, LIFE is a mix of PROS and CONS.

regarding the country, china is officially going to TD-LTE due to "population rationals":eek: 1.3 Billions bro (and even getting higher)
of course, i'm talking about Jam+traffic+fading stuff that deteriorate the FDD frame structure (less immune):D

ohh, by the way, reportedly, FDD is going worldwide. operators are re-farming their bands now...the rare few will have the luxury of using 20MHz or 15, so they have to inject their LTE into their existing tech (gsm+umst)....personally, i don't trust the part (lower cost than ever)...it just an appetizer for the consumers... and LTE's real power in higher bands...1.4MHz will not be that much compared to HSPDA+...
ended up with latest ITU's decision that LTE is 4G, after being 3.9G.........Man, in the end it's a huge game, Agilent and Intel+ other operators control the successors of wireless broadband technos....



regards man.....:)

[labviewlover]

here's the PDF part. sorry something went wrong with uploading last attempt:D

[T_ADD]

ok, great I'll go through it.

Meanwhile let's see what others might have to say.

I spoke to a Huawei marketing guy and he stated that though Huawei has developed both, there are no FDD UEs available right now. Now I'm not really sure on the correctness of his statement but just putting the info here for everyone and anyone to input.

[kpmanoj]

Hi,

Topic caught my attention...I think you got it wrong. Actually now there aren't many TDD devices but this will change dramatically since China & India (basically 1/3 of the world) will go TDD. However for now FDD is leading the way largely due to US at 700 MHz and Europe 800 MHz (DD) and 2600 MHz. 1800 MHz will also be refarmed to LTE.

Eventually, we see that both FDD and TDD will co-exist. The question of which variant to adopt will basically depend on the frequencies that you have.

All the best...

[T_ADD]

Hi, its making some sense. appreciate your input. I may have got the wrong impression initially.

[arjaypanganiban]

Hi Hactic,

I was able to run through some LTE stuffs when I was still in planning. I think the duplexing technique that you should use depends on your alloted frequency spectrum and demand on capacity that you should plan. FDD requires one Uplink and one Downlink frequency which are separated on the spectrum. When using TDD, your uplink and downlink are both on the same frequency.

[aminkhan]

Hi,
Kindly attached are some information about TDD & FDD.

[cooltyger]

I think the whole question of TDD or FDD is also based on the availability of spectrum in a specific geography or country. In US and Europe spectrum was made available in major chunks to support the FDD principally. Whereas in India the spectrum was occupied by the military and released for public use recently.
Cost is also kind of a driving factor in many countries and if my understanding is correct the TDD system costs substantially less than a FDD.

Also I have my own doubts if a TDD system can be designed in the 700 MHz scenario?? Hope some one can shed some light.

[T_ADD]

Hi cooltyger, I couldn't agree less. I've also come to the same conclusion. That the primary decision making point for operators would be what part of the spectrum they have available.

Both have certain advantages and disadvantages. For TDD just because it uses 1 frequency, the RF part might be less complex therefore a possibility to reduce cost. But one major disadvantage that can be seen, is TDD has far less coverage than FDD at around 700 - 800MHz. The higher the frequency goes the lower the cell coverage would become. This is turn could mean deploying more Base Stations (eNodeBs).

For a tropical terrain, I guess FDD at around 700 - 800MHz would be more suitable due to absorption factors.

It would be interesting for me too to understand why TDD has not been developed for the lower band 700-800MHz.

Is it true that 3GPP is focusing more on the FDD than the TDD? Hope some one can answer this too.

Much thanks.