LTE : Difference between ERAB ID, Logical channel Id and DRB identity ?

Question

For data plane, an end to end bearer is setup. I got confused why different different names are being used for same bearer.

Answer 1

Spec 36.300 , Section 13.1 Bearer Service architecture will provide you the answer to your question.

Answer 2

On top of the what Shyam has described the following is the mapping and yes these three are the terms which describes three different stuff at different level.

If EPS bearer ID is = x +4 ; 
Then 
DRB ID = x; 
Logical Channel ID = x + 2; 

NOTE : All these ranges is with respect to DRB establishment

EPS Bearer ID Range is INTEGER (0..15) (But 0-4 is reserved so we use starting from 5 )
DRB ID Range is INTEGER (1..32) (As in LTE max 8 DRB can be established per UE so we use from 1-8)
Logical Channel ID range for DRBs is INTEGER (3..10) ( For for DRB1 we use 3 as logical channed ID)

Comments

Really nice explanation.

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Hi All,

Is it correct to say that for each DRB only 1 Logical channel is associated.

The previous comments mentions that in LTE max. of 8 DRB can be established per UE. But as per page 652 of 36.331 V13.2.0, the max no. of DRB is 11.
"maxDRB INTEGER ::= 11 -- Maximum number of Data Radio Bearers"

Based on what source are we saying that max. DRB in LTE is 8 and not 11.

Thanks

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This is a very old thread please ask a fresh question.