• BTS Multiplexing Mode Huawei BSC6000

This describes how to change the BTS multiplexing mode to improve the utilization of the Abis timeslot resources. If the BTS uses the TDM transmission mode, the requirement for BTS timeslots changes when the BTS traffic increases. In this case, the BTS multiplexing mode should be changed.

BTS multiplexing mode indicates the Abis timeslot multiplexing mode of the BTS. It consists of the following seven types:

• 1:1 64 kbit/s statistic multiplexing mode
• 2:1 64 kbit/s statistic multiplexing mode
• 3:1 64 kbit/s statistic multiplexing mode
• 4:1 64 kbit/s statistic multiplexing mode
• 5:1 64 kbit/s statistic multiplexing mode
• 6:1 64 kbit/s statistic multiplexing mode

Physical 16 kbit/s multiplexing mode
The bandwidth of each E1 is 2.048 Mbit/s and is divided into 32 timeslots. The transmission rate on each timeslot is 64 kbit/s. The bandwidth of each T1 cable is 1.544 Mbit/s and is divided into 24 timeslots. There are six types of Abis timeslot objects:

Operation and Maintenance Link (OML). One BTS has one 64 kbit/s OML. The OML cannot be multiplexed with the RSL of another BTS.
Radio Signaling Link (RSL)Each TRX has one 64 kbit/s RSL. The RSL cannot be multiplexed with the OML or RSL of another BTS.
Extend Signaling Link (ESL)If the Abis timeslot assignment mode of the BTS is set to Flex, one BTS requires one 64 kbit/s ESL to transfer the Abis timeslot dynamic connection message. In 64 kbit/s statistic multiplexing mode and physical 16 kbit/s multiplexing mode, the ESL can be multiplexed only with the OML of the same BTS onto a 64 kbit/s timeslot on the same E1.
Traffic Channel (TCH)The transmission rate on the TCH is 16 kbit/s.
IdleIdle timeslots of the BTS. The rate of the idle timeslots is 16 kbit/s. The idle timeslots can be multiplexed only with the TCH in the same cabinet group.
SemiMonitoring timeslots of the BTS. The rates of monitoring timeslots are 8 kbit/s, 16 kbit/s, 32 kbit/s, and 64 kbit/s. Monitoring timeslots cannot be multiplexed with other types of timeslot objects.
When changing the BTS multiplexing mode, pay attention to the following:

If the BTS multiplexing mode is 5:1 or 6:1, the Abis timeslot assignment mode must be set to Flex Abis.
If the Abis timeslot assignment mode of a BTS must be set to Flex Abis, you should add an ESL for the BTS, and change the maximum number of RSLs that can be multiplexed with the OML.
When the BTS multiplexing mode is 4:1, if the Abis timeslot assignment mode is Fix Abis, a maximum of three RSLs can be multiplexed; if the Abis timeslot assignment mode is Flex Abis, a maximum of two RSLs can be multiplexed.
When the BTS multiplexing mode is 4:1, if the Abis timeslot assignment mode is modified from Fix Abis to Flex Abis, a redundant RSL will occupy a 64 kbit/s timeslot, thus reducing the utilization of resources. In this case, you can change the BTS multiplexing mode to 5:1 or 6:1. Therefore, more RSLs can be multiplexed onto one 64 kbit/s timeslot. This saves the system resources.
If the Abis timeslot assignment mode is Fix Abis or SemiSolid, the BTS multiplexing mode cannot be set to 5:1 or 6:1.
On the BTS cascading main link, the BTS in physical 16 kbit/s multiplexing mode cannot coexist with the BTS in other multiplexing mode.
When you change the multiplexing mode of a BTS from non-4:1 to 4:1 or from 4:1 to non-4:1, the related cell parameters are modified automatically.
When you change the multiplexing mode of a BTS from non-4:1 to 4:1, the measurement report preprocessing parameter of all the cells under this BTS is set to Yes and the sent frequency of preprocessed measurement report is set to once every second automatically.
When you change the multiplexing mode of a BTS from 4:1 to non-4:1, the measurement report preprocessing parameter of all the cells under this BTS is set to No and the sent frequency of preprocessed measurement report is set to twice every second automatically.
Multiplexing Mode :

BTS multiplexing mode indicates the Abis timeslot multiplexing mode of the BTS. The OML and RSL are signaling links. Only signaling links can be multiplexed together. Statistic multiplexing mode means that the OML and RSL use one E1 timeslot through Time Division Multiplexing (TDM). For example, 4:1 multiplexing mode means that three RSLs and one OML are multiplexed onto one 64 kbit/s timeslot.

If the BTS multiplexing mode is set to 5:1, one OML, one ESL, and two RSLs are multiplexed onto one 64 kbit/s timeslot, or five RSLs are multiplexed onto one 64 kbit/s timeslot.

If the BTS multiplexing mode is set to 6:1, one OML, one ESL, and two RSLs are multiplexed onto one 64 kbit/s timeslot, or six RSLs are multiplexed onto one 64 kbit/s timeslot.

If the BTS multiplexing mode is set to Physical 16 kbit/s, one OML (ESL) and one RSL occupy one 16 kbit/s timeslot respectively.