Algorithms for choosing between 2G,3G,(4G)

Dear community

Are there algorithms in the 2G/3G/4G standards that define which mobile network (in terms of technology) is logged into?

e.g. The mobile phone receives a 2G and a 3G base station from the same provider. The 2G base station with a level of -80dBm and the 3G base station with a level of -90dBm. Do the standards define which network a cell phone would log into? And at what level difference does the cell phone prefer the 2G network? Thank you for your help!

Kind regards

Much love

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Of course there are algorithms for this. Each cell phone manufacturer probably has a different algorithm and slightly different criteria and thresholds for switching cell networks.

If the cell phone is in idle mode (no phone calls, no data to be transferred), the main criterion for changing the cell phone antenna, frequency band and cell phone technology (4G/LTE -> 3G/UMTS -> 2G/GSM) is certainly the received signal strength (2G /GSM: RxLevel).

If the cell phone is in work mode (ongoing telephone conversation, lots of data to be transferred), the main criterion for the change will be the bit error rate of the data stream:

http://www.itwissen.info/BER-bit-error-rate-BFR-Biterrorrate.html

The bit error rate in 2G/GSM is output via the RxQual value in the network monitor:

The value:

GSM: RxQual

in the Samsung network monitor (*#0011#) corresponds to this
Bit error rate of the received mobile signal

RxQual = 0 Very good voice quality
RxQual < 4 Sufficiently good voice quality
RxQual = 4 Critical speech quality (insufficient)
RxQual > 4 Poor voice quality (insufficient)

RxQual = 0 => BER < 0.2%
RxQual = 1 => 0.2% < BER < 0.4%
RxQual = 2 => 0.4% < BER < 0.8%
RxQual = 3 => 0.8% < BER < 1.6%
RxQual = 4 => 1.6% < BER < 3.2%
RxQual = 5 => 3.2% < BER < 6.4%
RxQual = 6 => 6.4% < BER < 12.8%
RxQual = 7 => 12.8% < BER

BER: Bit Error Rate

The mobile communications standards/mobile communications technologies can be compared to the automobile roads:

2G/GSM => reception everywhere, no transmission capacity and no comfort => dirt road, mobile with 4×4

3G/UMTS => Reception in inhabited areas, good transmission capacity and good comfort, but not accessible in peripheral regions => 2-lane, tarred road, drivable with a normal car

4G/LTE => reception in inhabited areas, very high transmission capacities and very high comfort, but not accessible in peripheral regions => 4-lane highway

Since 2G/GSM is best suited for the peripheral regions of mobile network coverage due to the radio technology, all mobile phones switch to 2G/GSM when mobile signal reception is poor.

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Hello GrandDixence

Many thanks for your response. I’m particularly concerned about idle mode at the moment. Then switching between technologies in idle mode is device/manufacturer-specific and not standardized?

Kind regards

Much love

Show original language (German)
3 months later