The first thing I should mention as I always do, please stop calling LTE as 4G as its commonly called as 3.9G. Labelling it as 4G does make it sound better (or sexy, some would say) but its not correct. Maybe the authors who label LTE as 4G dont want to try hard and do some research or its just to make the end users panic that India has missed a complete generation of mobile technology. LTE-Advanced will be the 4G technology and its still long way away (part of Rel-10).Last week I wrote about Indian subscribers getting taste of 3G as the state owned MTNL and BSNL have launched some services. I am not sure what has been launched but all I can say is there is a dismal takeup as of yet. I read an article today about how Motorola is testing 4G [sic] and this can spoil the governments plan of rasing Rs 35,000 crore (£4.6Billion: 1Billion = 100 crores).
People may start panicking that investing in 3G is now doomed and it can just cause problems for the operators in future. The reality though is much more simpler. In a simple sentence, I would say that going for 3G or LTE does not matter much. Read on.
Lets first get Hardware out of the way. Most of the Base Stations (NodeB's, eNodeB's, RNC, etc) have a major part as SDR's or Software Defined Radios. The advantage of this is that if you have bought a 3G Node B, with just software change it should be upgradable to LTE eNode B. I have come across quite a few products where the equipment manufacturers are claiming that their 3G equipment is fully upgradeable to LTE. I did blog about some of this in this post here.
The second point we should get out of the way is the terminology. For a layman, 3G is something that was introduced 10 years back in 2000 so its quite an obsolete technology. In reality, 3G is commonly used to refer to even the new developments within the 3G spectrum. For example some of the people may have heard of HSDPA which is actually referred to as 3.5G in the mobile domain. Similarly we have HSUPA which is 3.75G and so on. The latest development is going on around 3.8G and 3.85G as part of Release 8. In general usage 3.5G, 3.75G, etc. is referred to as 3G but its more than 3G (3G+ ;). The good thing is that this 3G+ is till evolving. Release 8 was finalised in Dec. 2008 and the terminals based on that are still being tested. It should hopefully be available soon.
So whats the difference between LTE and HSPA+ (also known as 3G even though its 3.8/3.85G). Not much I would say from a general users point of view. Please note I am not arguing about the fundamental technologies because 3G+ uses WCDMA and LTE uses OFDMA/SC-FDMA technologies. OFDM based technologies will generally be always superior to WCDMA ones but it doesnt matter much. The main enhancement that has happened with LTE as compared to 3G is that in 3G the bandwidth is fixed to 5MHz whereas in case of LTE the bandwidth is flexible and can go all the way to 20MHz. Now if we compare the data speeds in 5MHz spectrum then there may not be much difference between them. Now how many operators will be rolling out services across 20MHz bandwidth? More general case will be using 10MHz.
In case of HSPA+, there is a new feature that allows a UE to use couple of cells. In this case even though the bandwidth is 5MHz but due to Dual Cell feature the UE would effectively see 10MHz bandwidth. This will definitely enhance the speeds.
Now coming to devices. 3G/HSPA/HSPA+ technologies have evolved over quite few years. There are some nice sleek and cheap handsets available. The technology in it as been rigourously tested. As a result the handsets are quite stable and many different design and models available.
LTE is yet to come. NTT DoCoMo and Verizon will be the first one to roll it out probably end 2010. Initial plan is to roll out the dongles then handsets will the eventually arrive. The initial ones will have problems, crashes, etc. Will take atleast till 2010 to sort out everything.
The big problem with LTE as many of us know is that the standards have to support for the old style CS voice and SMS. This should be fixed in Release 9 which is going to be standardised in Dec. 2009 (Mar. 2010 practically). There are different approaches and maybe untill LTE is rolled out we wont know which of them is better.
Last thing I should mention is the spectrum. The consensus is that 3G operates in 2.1GHz spectrum mostly worldwide. LTE would initially be deployed in 2.6GHz spectrum. The digital dividend spectrum when it becomes available will also be used for LTE. Most of the devices for LTE will be designed that way. As a result, 3G will continue to operate as it is in the 2.1GHz band. The devices will always be available and will be usable for long time.
Considering all the facts above, I think 3G (HSPA/HSPA+) is the best option in India or as a matter of fact in any country that is thinking of jumping directly from 2G to LTE. When the time is right, it should not be difficult to move from 3G to LTE.
I totally agree. More over there are not may bandwidth hungry people in India yet.
ReplyDeleteThank you sir, very useful information for us.
ReplyDeleteTrue 3G is the way forward for India and in no ways it is late but infact is it just the right time to deploy 3G in terms of market and pricing. If we look at the 3G coverage in UK it is just about half of what is covered by 2G so 3G is still maturing and deployed after 9 years of being standardized. If we look at the world GSM statistics 81% still use GSM and about 17% is 3G and it will take years if not a decade before LTE or LTE advance will mature and be ready for wide scale deployment. I recall reading in a market research paper that only around 2012-13, wide scale LTE(not LTE advance) enabled mobile phone will be available. Its a long way for LTE keep aside 4G.
ReplyDeleteIt's true that India, at present doesn't have to care about LTE deployments. Because the existence of stabilized LTE networks may take time. As 3G networks are almost stabilized all over the world, India can go head with 3G without any second thought.
ReplyDeletefor india spectrum is scarce resource. even it is not started allotment for 3G... 20 MHz for 4G will be difficult phase. opportunity cost of 3G is still there, moreover upgradation can be done at any stage. so practical approach is to adopt 3G and wait for 4G.. if resources allow you upgrade ur network.
ReplyDeleteThanks for the nice post...
ReplyDeleteThats correct. But till now 3G deployment in India is far behind the schedule. The spectrum allocation is not over as well. Let's see when 3G will be fully available in India.
ReplyDeleteThanks Zahid. Good info. I had a good time reading valuable info. about LTE. However, please elaborate more on 10MHz BW use for LTE in your next post. You had mentioned that the BW could go all the way upto 20MHz but I could not understand why the manuf. would be keen on using the 10MHz when they could go to all the way upto 20MHz?
ReplyDeleteHi Sun,
ReplyDeleteIts not the manufacturers that will go for 10MHz or less but the operators. Initially for LTE, you need to have a contiguous spectrum. In all the countries, this contiguous 20MHz spectrum may not be available. Even if its available there may be many operators and for the sake of competition, the authority will have to allocate spectrum to many operators. This may result in operators ending up with 10MHz or 5MHz bands. LTE is able to cater for many different bandwidths and the standards are written in such a way that the handset/dongle will work regardless of the bandwidth.
Regards!