Basic knowledge E1 Calculation

[f1cy]

Hii friend,

This is E1 Calculation Base on Radio Configuration of Cell.


BR//
f1cy

[hassen]

Hii friend,

This is E1 Calculation Base on Radio Configuration of Cell.


BR//
f1cy

what about LAPD ,configuration 4/4/4 at minimum require 3 ts 64kb/s

1 site 4+4+4 = 27 ts

[f1cy]

what about LAPD ,configuration 4/4/4 at minimum require 3 ts 64kb/s

1 site 4+4+4 = 27 ts

As i know,
1 TRX = 2 ts
12 TRX = 24 ts
1 E1 = 32 ts

If 1 site config 4/4/4 = 12 TS, need 1E1 star 31
CMIW

[cekerayam]

As i know,
1 TRX = 2 ts
12 TRX = 24 ts
1 E1 = 32 ts

If 1 site config 4/4/4 = 12 TS, need 1E1 star 31
CMIW

you can configure 15 TRX with only 1E1, using Abis optimization technique. i will send the document separately.

[cekerayam]

what about LAPD ,configuration 4/4/4 at minimum require 3 ts 64kb/s

1 site 4+4+4 = 27 ts

Hi,
1 E1 = 32 Time Slot. 1 timeslot will be used by Link management (Ts 0).

12 TRX = 2x12 Ts = 24 Ts
12 TRX need 12x32 Kbps (0.5 Ts) = 6 Ts <--LAPD/TRX Signalling
12 TRX need 12x16 Kbps (0.25Ts) = 1 Ts <--- BCF Signalling

Total = 24 Ts+6Ts+0.25Ts = 31 TS equal to 1E1.

We can configure 15 TRX using 1E1 (using Abis Optimization technique).

tks

[f1cy]

you can configure 15 TRX with only 1E1, using Abis optimization technique. i will send the document separately.

can you share Abis optimization technique, thx alot bro

[hassen]

what about LAPD ,configuration 4/4/4 at minimum require 3 ts 64kb/s

1 site 4+4+4 = 27 ts

TRXs/site--- --------------Time slot for signaling


1 TRX, no concentration --- 1
2 TRXs, concentration 2:1--- 1
3 TRXs, concentration 3:1--- 1
4 TRXs, concentration 4:1 ---1
...................................................................................

Time slots for traffic--- Time slots per TRX, total
2 ---------------------------3
4 ---------------------------2.5
6 ---------------------------2.33
8----- ----------------------2.25


It means 4 TRXs, concentration 4:1(0.25) =>2.25*4=9
configuration 4+4+4 need 9 * 3 = 27
ie 27 Time slot 64Kbit/s

The benefit of LAPD concentration is a reduced number of required physical links between the BSC and the RBS
LAPD concentration is recommended to be used for RBS sites with 2 TRXs or more per cell when traffic signalling is not too high.
Examples of transmission savings assumes no use of CS 3/4 or EGPRS, i.e. no use of 64 kbit/s Abis paths per BPC





Hassen

[ghassen]

it depend from manufucturer techniques for pcm configuration and also from which codec scheme are used on the air interface when you are using gprs or edge and this is what we call flexible abis alocation strategie and it is not relevant for all equipment it's different from nokia side to siemens
example : speech
1 trx to 2 trx = 1 lapd at 16 kb/S
more than 2 trx at least 1 lapd 64 kb/s

[faib]

yup it varies from vendor to vendor , like in

a) Motrolla they use their own interface " MAbis" and you configure RSL per site basis rather than per TRX ( interesting )

b) Alcatel use different Multiplexing schemes for RSL mapping per TRX basis eg 16k Static multiplexing, 16K statistical multiplexing , 64 k statistical multiplexing , no multiplexing where OML is configured on per site basis (as usual mentioned in GSM specs )

c) Siemens , Nortel, Nokia , Huawei use RSL per TRX and OML per site basis ..

well FOR EDGE , GPRS your Abis planning is required , like in Alcatel with B8 version if you are configured MCS9 on whole TRX then 1 TIME SLOT will be mapped on 4.8 X 1= 4.8 NIBBLES ( where 1 TS on Abis = 4 Nibbles )

well in new version like B9 , B10 of Alcatel they have introduced " Flexible Sharing of Abis resources " per site basis and you will find same features in SIEMENS , Huawei etc etc


i try to explain TRX MAPPING on LAPD channels as per my best knowledge

correct me if i m wrong cuz we all in the phase of learning

Regards,
Faib

[cekerayam]

can you share Abis optimization technique, thx alot bro

Hi,
As promised, attached is some slide about abis optimization. actually, its depend on vendor how to configure abis optimization. this is just for your review.