Difference between LTE and WCDMA to handle high radio congestion

Hello Experts.

My operator is working in remote area where it is the only operator to provide service, and population density is very high due to which even getting connecting to 3G is very difficult.
I checked the KPIs and found that RRC and RAB SR is very low and RTWP is very high.
I assume it is due to radio congestion.
But 4G works fine although slow but RRC & ERAB SR is good.

Can anyone explain what is difference in LTE technology from WCDMA that it can handle high radio congestion?

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What is bandwidth in both?

It is 5 MHz.

3G have 1 room for both UL and DL user while in LTE different.
Possible 3G not working over there.

3G and 4G are different technologies altogether (unlike 4G and 5G which are similar).

In 3G, more device in area (or in poor RF) more overall RTWP. As RTWP increases devices start shouting louder, increasing overall noise floor. In 3G every device uses entire 5MHz spectrum.

Whereas in 4G devices are allocated subcarriers depending on their own RF profiles (so much more efficient).

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Yes, I agree. :+1:

Ok, you mean 1 tti shared in LTE while it is allocated to a single user in 3G.
What about interference control in 3G?

Didn’t understand your point, but (very simply):

4G each TTI different subcarriers can be allocated to different users e.g. so 20MHz spectrum can be share among 10 device but each will have their own frequency resource i.e. they don’t share same frequency resource.

In 3G, each TTI, 10 devices all share same 5MHz resource and they are distinguished by different codes (forgot what those are called in 3G)

Interference was biggest bottleneck in 3G technology (hence 3GPP moved away from that technology completely). There are many interference mitigation mechanism: limit soft handovers, reduce signaling, reduce RACH ramp up cycle etc. But these are all optimisation which can give you very minimal benefit.

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Agree. In my opinion the CDMA was a big limitation to 3G, the interference was a nightmare for 3G.
If it comes to me, I would switch off 3G and keep only LTE 5G along with 2G for CS.

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This is due to CDMA technology causing intra cell interference between devices.

Why CDMA is still considered a better technology than GSM for voice even though it lost the market to GSM?

It’s time to walk away from CDMA and GSM, two technologies in their twilight years. No matter how much you love your old phone, you need to move to 4G or 5G.

Really? But why?

Top 8 GSM vs LTE differences to Learn with Infographics

Inspite of all good feature no where it’s in use, operational.

CDMA VS GSM: Which platform should you pick?

Soft handover gain.

Also spectrum efficiency.

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Of couse CDMA… but because of Qualcomm chips.
Royalty was quite huge.
Even with a single bar you could talk without any voice break for soft softer handover gain while travelling.
Unlike GSM.

In UMTS channelization codes are othogonal but scrambling codes which distinguish each transmitter is not completely orthogonal. So in UL each UE has seperate scrambling code(not completely orthogonal) and using same frequency. so with increasing user ul interference increase and hence capacity reduced.

In LTE each subcarrier is completely orthogonal, i.e. the frequency is different for different user.
So interference is less.
So such limitations in interference.

In Ericsson there are RBS parameter which can increase maximum sustainable interference in a NodeB (maxrotcove, and few simililar in same mo i dont able to recall fullname) + you have some features like interference suppression, fast congestion control and many more.

Please check if all are activated and you can tune this parameters as well.

I guess basic admission parameter you already maximized and suppressed r99 rabs already.

All parameter, feature I mentioned are available for ericsson vendor,I guess similar will be there for other vendor as well.

I guess GSM is still much better than WCDMA, with 5 MHz and good frequency planning you can handle more CS traffic than the 3G can do.

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I’m glad that i’m not The only one that wishes we turned off the 3G network instead of GSM!
For CS traffic GSM is Way better than WCDMA.

3G radio resources necessary for one UE is many: DL/UL CE, DL/UL Tx power, Iub bandwidth, HSDPA/HSUPA user number, DL code.
While 4G radio resource is few: PUCCH, SRS, user number
If one resource is congestion, can not setup signaling/traffic channel for UE.
And 3G resource is not easy to adaptively change as 4G resource, 3G resource at nodeB is managed by RNC, make it more difficult to adaptive as only controlled by enodeB as 4G.

So, to setup resource for new UE in 4G is easier than 3G, less congestion in 4G.