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3G mobile communication: roadmap and a problem |
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23.05.2007 г. |
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No matter how eager you are about to use 3G mobile phone, let me tell you, it is completely different ball game. To start with, all the available 3G communications are variants of CDMA, and mostly consists of W-CDMA and CDMA 2000. Both W-CDMA and CDMA has their variants too, but they are two most common technologies for 3G mobile network. Current GSM operators in Ukraine can be considered upto 2.75G for EDGE.
The CDMA 2000 and W-CDMA are defined to operate at 400 MHz, 800 MHz, 900 MHz, 1700 MHz, 1800 MHz, 1900 MHz, and 2100 MHz. And we already know for GSM networks, 900 MHz and 1800 MHz frequencies are used in Bangladesh. To proceed further, I need to elaborate the current nature of 3G networks and mobile phones. Currently GSM phones like Nokia N-series and Sony Ericsson K800i, which supports 3G, have both the GSM module and W-CDMA module and 3G operators are providing both GSM and W-CDMA service, so GSM can be used for calling and W-CDMA can be used for internet browsing, video conferencing etc. For the CdmaONE users like Citycell in Bangladesh, it is easier to upgrade to 3G. Because CDMA2000 variants are the upgraded versions of CdmaONE and doesn’t require dual receiving system in mobile phone.
So for the GSM companies in Bangladesh, they need to deploy a W-CDMA network at 2100 MHz to provide the 3G communication. Because it is the most common form and the exisiting 3G mobile phones (Nokia N-series and Sony Ericsson K800i) can only operate in this system. It is important to note that this W-CDMA 2100 will be deployed along with existing GSM 1800 network by the same operator.
Now the reason for writing about 3G - one of my readers expressed concern over the future deployment of W-CDMA 2100Mhz network in Bangladesh. According to him, Jubok Phone (telebarta) has been given the licence to use CDMA 1900 Mhz frequency. The CDMA Base Transmission Centers are known to cause interference to nearby GSM Base Transmission Centers of close frequencies. For example 800 Mhz CDMA BTS can cause interference in GSM 900 Mhz BTS, so call drops can occur. Same is applicable for CDMA 1900 and W-CDMA 2100 networks. W-CDMA 2100 BTS can be affected by CDMA 1900 BTS. In Bangladesh, we may have problem with deploying 3G, if GSM 1800 (Grameenphone, Aktel), CDMA 1900 (jubok Phone) and W-CDMA 2100 (3G service provider) transmission centers co-exist in same area.
You might think, how can 1800 Mhz interfere with 1900 Mhz or 1900 Mhz with 2100 Mhz. Above is figure showing CDMA 800 downlink and its spurious emission interfereing with GSM 900 uplink. A similar scenario potentially exists for the case of UMTS: common variant of W-CDMA 2100 MHz co-located with CDMA 1900 MHz. In this case it is the UMTS(W-CDMA) receiver (actually operating in the 1900 MHz band) being affected by CDMA 1900 transmissions. Similarly GSM 1800 transmission can also be affected by CDMA 1900 interference.
So if there’s problem in 3G deployment because of unplanned frequency allocation by BTRC - think about it, more CDMA 1900 BTS, more interference with 3G network and so poor 3G data transmission. Now this problem has been occured in many countries including India and China, because of the contention between CDMA and GSM operators over the 1900 MHz band. The common solution to this problem is to use filters in BTS if we want to keep CDMA 1900 jubok phone with W-CDMA UMTS 2100 3G network. Filters have to be used in both the transmitters and the overall process will cost a lot to upgrade all the transmitters. Another solution is, as 3G is a completely different system, the existing GSM 900/1800 companies can convert to in-band W-CDMA 900/1800, rendering current mobile handsets incompatible to the upgraded network. But whatever the solution is, 3G is still a long way to achieve for GSM providers in Bangladesh. Still EDGE service, provided by grameenphone is sometimes considered 3G depending on data speed. but CDMA companies can easily provide 3G by upgrading to CDMA2000 1x, CDMA2000 1xEV-DO system.
So 3G is very much possible if we have need for it. i would like to thank Mr. Hasan for bringing this matter into my knowledge. if you want to know more, just click here:
Radio frequency systems online bulletin
In-Band 3G W-CDMA: The Comercial Potential
GSM
CDMA2000
3G
W-CDMA
UMTS
Mr. Hasan’s Email Compilation:
So far only Grameen have EDGE available for use. (eg. like i m sending u the mail using GP EDGE from my Laptop connected to my Nokia 6680 with built-in EDGE modem. Very convenient for me residing at Mirpur (where I have a poorer so-called Bangladesh Broadband connection).
I worked closely for Warid case earlier. So far i know they dont have plan for anything better than EDGE for data service at the time of launching. (except like i mentioned Canopy from MOTOROLA-which is completely seperate network and cant be accessed with 2G or 3G mobile system). And for your info, in Dhaka city they will have the same EDGE by Ericsson given to Grameen. Sylhet and Chittagong Wrid will have MOTOROLA-who is very poor performer of EDGE network. So I see a little chance for Warid to turn out to be a better player than Grameen. Moreover Warid dont have 900 MHz frequency unlike Grameen-which technically is BIG disadvantage for Warid and will increase CAPEX for Warid.
For students or Business guys today voice is not enough. Data service is a MUST-HAVE for us. I am terribly shocked by the fact that Bangladesh wont have 3G as the Frequency is given away in a stupid and unplanned way, when as of today i see countries like Srilanka, Cambodia, even Vietnam are in 3G zone already. I dont understand how long we will remain stupid as we were (like the case of connecting to Submarine cable in 1990s)
Sad but true. I want to escape-when my co-workers say- oh! Bangladesh- No chance for 3G- u r too slow to realize where the world already is now today.
The thing is every technology/media has it’s specified standard Frequency. For example,
GSM are widely used in : GSM 900, GSM 1800 MHz (U c most handsets are Duel-band (900 & 1800) or triple Band (1900) or even Quad-band (2100)). Grameen, Aktel, Blink, Teletalk, Warid are in this category. So far these are specified to be used for 2G, 2.5G or anything less than 3G.
3G is defined to be used in 2100MHz. This is whole new technology evolution in 3rd Generation Mobile (3G) and onwards like 3.5G > 3.9G or later(HSDPA>HSUPA>LTE).
Now as usual, the Battle is on between USA & EU countries. EU and most of the countries World-wide use 1900MHz & 2100MHz and 3G-WCDMA technology. only USA choose mixed of 1700 & 2100 MHz for 3G which is very unique for them (u know, they tend to think they are superior so they should have unique-since they have money, they probably will succeed in doing this). Japan & Korea already for long time using 3G in 1900MHz & 2100MHz.
Another thing is the old Battle of GSM (Widely used world-wide except USA) & CDMA (used in USA and tried to push to rest of the world but failed and going to die soon at the wake of 3G WCDMA pushed by EU countries and the rest of the world) technology. Today the world have more than 80% Mobile subscriber using GSM (that will evolve to WCDMA/3G). CDMA have less than 15% most of which is from USA alone. And dieing operators like Citycell in Bangladesh.
Now u will agree Bangladesh cant afford to follow USA. Unfortunately BTRC have given away 1900 MHz to even smaller operators like Jubok-Phone and some other to be used for CDMA Wireless-local loop. I really hate to see American Bitches like MOTOROLA (the vendor) QUALCOMM (the CDMA technology promoter). This CDMA 1900 blocks both GSM 1800 & WCDMA 2100 since CDMA 1900 is a self-interfering operating system. I really hate American dirty politics and developing countries pay the price sollowing the bait. Also the interesting thing would be to see MOTOROLA is the supplier for GSM 1800 in Warid and CDMA 1900 in Jubok-Phone (Telebarta). Ericsson gave up CDMA long time back so that they can focus WCDMA heavily.
Sad that for 1 year I was working to promote CDMA, no-one told me that there will be interference with GSM & future-WCDMA. Once I started working for GSM & WCDMA, i found countries like Indonasia, Malaysia, Phillipines had the same mistake 3-5 years back and ultimately decided to remove CDMA out of the way of WCDMA and today have 3G in place. Like i said Srilanka, Vietnam, Cambodia joined the list as well.
Now, I probably confused u more than giving solution. But the truth is unless we remove CDMA 1900, we wont have 3G in place for use.
It’s easy to say anyone will use Filter. Do u think All the GSM operators together have over 10 thousand BTS will use Filter and that would eliminate the interference? If true- why TRAI in india still waiting to evacuate CDMA 1900? They have recently decided WCDMA 2100 and CDMA 800 will be used for 3G technology. But it would still take time for them to do so.
Relience-the giant CDMA operator have taken steps to move to GSM/WCDMA and tring to buy stakes in Hutch-the GSM operator.
The debate in India is the same in Indonasia, Malaysia and philipines but the difference is Indonasia, Malaysia and Phillipines succeeded to eliminate CDMA 1900, and so they got to start WCDMA earlier. India still lingering.
December 01, 2006 Lucent is bought by Alcatel and then they also decided to start producing WCDMA-so they bought Nortel WCDMA department for some USD 340 million cash!!!
1) GSM 1800 is currently used by Grameen and Aktel. Although it is not
available in all the places. How are they operating if cdma 1900
blocks them
In fact all the GSM Operators in Bangladesh have GSM-1800. (including Warid & even Worldtel). Lucky us-the Band is wide and CDMA WLL in Bangladesh is still small (Probably Telebarta/Jubok Phone have 75 BTS across Chittagong Division, Some part of Greater Dhaka/ Sylhet- so if u r from Chittagong- sorry to say until Telebarta give-up, u wont have 3G deployment in Chittagong). The issue will be more visible once the CDMA 1900 Operator start to deploy BTS close to GSM-1800 BTS or WCDMA (3G BTS).
Let me give u other evidence Teletalk currently have the overlapping frequency GSM-900 & CDMA-800. So the sites where Citycell have CDMA 800 BTS close to Teletalk GSM 900, Teletalk having poor performance.
2) for 3G which frequency is appropriate for GSM network, GSM 1800 or
2100? if it is gsm 2100 mhz, will cdma 1900 block gsm 2100?
Let me simplify: for GSM operators evolution path is like
2G evolution: GSM > GPRS > EDGE > EDGE-evolution (using GSM-900 and GSM-1800)
then the next technology migration as follows:-
3G evolution: WCDMA > HSDPA > HSUPA > LTE (Begining with IMT-2000 specified band ie 2100 MHz core Band)
From 2G to 3G technical migration is BIG step forward. Though it took quite some-time for 3G to take off. But it is planned in such a way so that existing GSM Operators can run both 2G and 3G network parallely. However, end-user like u-if using 2G+3G Quad-Band handset, will not realize that there are 2 Neworks (2G & 3G), unless u look at the screen of your mobile, which one u are anchored.
3) is it possible to have more than one CDMA 1900 network, so citycell
can provide 3G?
Lucky us again. CityCell dont have CDMA 1900 yet-but they could have. Now they have CDMA-800. Which is best to disturbe Teletalk GSM-900 BTS if close to Citycell CDMA-800 BTS site.
CDMA evolution 2G>3G is:
IS-95 > A > B > 1x > 1x-EVDO > EVDV
However Qualcomm probably stopped further EVDV development. (I am not studying CDMA anymore-for last 1 year or so)
But Singtel is well-known and having Multi-operation for GSM > WCDMA > HSPA elsewhere. Only here in Bangladesh they have CDMA operation with CityCell. Still like many other CDMA operator, they can quit CDMA and Join WCDMA-if they like.
4)what is the solution to provide 3g through GSM network, if we have
CDMA 1900 operators?
Let me make the first thing clear. 2G GSM will continue parallely- even if all GSM Operators start 3G operation in 2100 MHz. This is good since many people may not afford to buy or probably dont need 3G.
No easy soution for Mixed-up mess. Push CDMA 1900 to the corner-give them time to evacuate 3G migration path for GSM operator. Try to push them to rural regions where 3G demand may be optional.
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