Dear all, Greetings…
I want to ask, what is the name of T200/N200 SDCCH parameter in E// or how to change them, I can’t found them in ENM ;( , or I can’t change them.
Thanks!
Hi. @Marwan97, we can not change T200/N200 directly. But we can change SIGDEL/LDEL, which is:
SIGDEL The parameter is set by command RXMOC per TG MO in BTS Logical Model G12 and per AT MO in BTS Logical Model G31.
SIGDEL can be set to LONG or NORMAL in BTS Logical Model G12.
SIGDEL can be set to LONG, NORMAL or MEDIUM in BTS Logical Model G31.
NORMAL sets the timer T200 to 240ms and the K value (window size) to 2 for OML and RSL links.
LONG sets the timer T200 to 1400ms and the K value (window size) to 11 for OML link and 15 for RSL link. The parameter should be set to LONG when using Abis Satellite connection.
MEDIUM sets the timer T200 to 400ms and K value (window size) to 3 for OML link and 5 for RSL link.
When SIGDEL is set to normal LAPD parameters (T200, N200 and window sizes) can also be changed by setting LDEL using RRSGI command per TG (Super channel group).
Handling of LDEL parameter is valid only for G12 BTS Logical Model.
LDEL can be set to 1 or 0.
LDEL = 0 normal configuration of LAPD parameters, T200 and K values according to SIGDEL, N200 = 3.
LDEL = 1 sets T200 to 400ms; N200 to 5; and the K value to 3 for OML link and 5 for RSL link.
Note: changing the T200 and N200 values affect both the BSC and the BTS.
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Hi. @vlr9999 Thanks for your response, but I think SIGDEL/LDEL paramters control the T200/N200 for LAPD, which is this protocol for the Abis link between the BTS and BSC.
As there is another protocol called LAPDm, which is for the Um link between the UE and BTS.
Meanwhile, in Huawei, they provide T200 / N200 for LAPDm that controls SDCCH / FACCH acknowledge time in the UM link as well as T200 / N200 for LAPD. But E// is out of coverage in this topic, I think.
Hi, @Marwan97, values for LAPDm are hardcoded also
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@vlr9999 what does hardcoded mean? does it mean these parameters can’t be change
Hi, @Marwan97, yes, there are some predefined values and we can not change.
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