Looping Back Remote Speech Channel

This describes how to start or end the remote speech channel loopback and how to query the status of the current remote speech channel loopback.

Prerequisite

The MS is in conversion.

Context

The speech in a system can be transmitted in sending direction and receiving direction. Each direction has its own channel. On a speech channel, you can locate the segment where the speech problem occurs by comparing the loopback speech with the original speech.

You can detect the speech channel fault by performing the remote speech channel loopback on the A interface and the Abis interface. If it is the internal problem that results in the speech channel fault, you can start the internal testing to locate fault.

Procedure

Through GUI
1. Choose BSC Maintenance > Maintain User Resource > Remote Speech Channel Loopback. A dialog box is displayed, as shown in Figure 1.
  Figure 1 Remote Speech Channel Loopback dialog box
2. Set parameters in the MSID area. Select a value in the Loop Location and Loop Direction drop-down list boxes. Click Start. A dialog box is displayed, showing that starting the loopback succeeds.
  NOTE:
  The parameters to be set in the MSID area must be the same as those on the peer end. That is, if the calling MS is in current BSC, the parameters are set to those of the called MS; if the called MS is in current BSC, the values of the parameters are set to the values of the parameters of the calling MS.
3. After starting the loopback, click Query. The query results are displayed, as shown in Figure 2.
  Figure 2 Querying status of the remote speech loopback
4. Click Cancel stop the remote speech loopback.
  NOTE:
  To end a remote speech loopback, click the IMSI, IMEI, TMSI, or the MSIDSN option button in the MSID area to make sure that the parameter type in the MSID area is the same as that previously set for the loopback.
  
  If different MS IDs are used for one MS to perform the remote speech channel loopback, you need to use corresponding MS ID to end the remote speech channel loopback.
Through MML
1. You can run the following commands on the LMT to loop back the remote speech channel.
  - Run the DSP RMTSPCHLOP command to query the remote speech channel.
  - Run the DSP RMTSPCHLOP command to start looping back the remote speech channel.
  - Run the DSP RMTSPCHLOP command to stop looping back the remote speech channel.