Repeated SACCH

Repeated SACCH

Last updated: December 3, 2008

This section is only applicable to the lab applications.

The Repeated SACCH functionality allows the SACCH Blocks to be repeated on both uplink and downlink to improve the robustness of the signaling link. You can choose to enable the Repeated SACCH functionality when a layer 3 message is to be sent or received in a SAPI=0 frame in the SACCH channel.

Repeated Downlink SACCH Blocks

On the downlink, you can use the Repeated SACCH parameter to set the Downlink Repeated SACCH functionality, when the Repeated SACCH is set to Continuous , each downlink SAPI=0 SACCH Blocks are repeated without any SAPI=3 SMS blocks in between. When the Repeated SACCH is set to On Request , the downlink SAPI=0 SACCH Blocks are only repeated after the test set receive SRR bit in the previous uplink SACCH Layer 1 block header from DUT. (The DUT monitors SAPI=0 SACCH Blocks and if it fails to decode then it sets the SRR (SACCH Repetition Request) bit in the next uplink SACCH block.) When the Repeated SACCH is set to Off , the downlink SACCH Blocks are not repeated.

   
NOTE
When the Repeated SACCH is set to On Request , the Downlink SACCH Blocks will only be repeated if the DUT has Repeated SACCH functionality implemented too.
   

The GPIB command to enable/disable the Repeated SACCH parameter is CALL:TCHannel:(SACCH|SACChannel):REPeat[:STATe] .

The following precedure details how to set the Repeated SACCH parameter.

  1. Press the CALL SETUP screen key.
  2. Press TCH Parameters ( F8 ).
  3. Press the More key untill screen 3 of 3 of the TCH Parameters menu is displayed.
  4. Press Call Signaling Parameters ( F7 ) and the Call Signaling Parameters menu appears in the center of the screen.
  5. Use the knob to highlight and set Repeated SACCH.

Repeated Uplink SACCH Block

On the uplink, you can use the SACCH Repeated Order parameter to set the Uplink Repeated SACCH functionality. When the SACCH Repeated Order is set to ON , all downlink SACCH Blocks shall have the SRO (SACCH Repetition Order) bit set in the Layer 1 downlink block header, the DUT repeats the SAPI=0 SACCH block when the SRO in the previous downlink SACCH block is set.

The Uplink SACCH Blocks will only be repeated if the DUT has Repeated SACCH functionality implemented too.

The GPIB command to enable/disable the SACCH Repeated Order parameter is CALL:TCHannel:(SACCH|SACChannel):REPeat:ORDer .

The following precedure details how to set the SACCH Repeated Order parameter.

  1. Press the CALL SETUP screen key.
  2. Press TCH Parameters ( F8 ).
  3. Press the More key untill screen 3 of 3 of the TCH Parameters menu is displayed.
  4. Press Call Signaling Parameters ( F7 ) and the Call Signaling Parameters menu appears in the center of the screen.
  5. Use the knob to highlight and set SACCH Repeated Order.

For more information about Repeated SACCH, please refer to 3GPP TS 44.006 and 3GPP TS 44.006 Section 11.

Related Topics

Repeated Downlink FACCH