Timing Advance

Timing Advance

Last updated: December 2, 2008

There are two methods in which the test set may inform the MS of the Timing Advance value, an assignment method or the Continuous Timing Advance Procedure .

Background

The test set allows you to assign the MS a timing advance value to test whether it alters its transmission accordingly. The timing advance value is initially specified in the Packet Uplink or Packet Downlink Assignment messages. If the timing advance value is altered during a data connection, the new value is sent to the MS in a Packet Power Control/ Timing Advance (PPTA) message.

Continuous Timing Advance Procedure

Continuous Timing Advance is an alternative method for assigning timing advance values. In the assignment/reassignment messages, in place of a timing advance value, the MS is given a timeslot number, and an index value. With these two parameters, the MS is able to look at the correct position in the Packet Timing-Advance Control Channel/Downlink (PTCCH/D) for its timing advance value. In addition, as part of this procedure, the MS periodically sends an access burst on the Packet Timing-Advance Control Channel / Uplink (PTCCH/U) on the given timeslot. Using the Continuous Timing Advance procedure, Packet Timeslot Reconfigure (PTR) or Packet Power Control / Timing Advance (PPTA) messages are no longer sent when the timing advance value is altered during a data connection.If the Continuous Timing Advance procedure is enabled, the MS has to delay transmission of the uplink TBF until it has received its timing advance value.

Timing Advance Parameters

You may specify both the state of Continuous Timing Advance and timing advance values when using Active Cell operating mode and all available Connection Types: Auto, ETSI A, ETSI B, and BLER.

Timing Advance and Measurements

The test set is able to adjust for up to four symbols of offset in the MS transmission. If the MS does not react to changes in timing advance, the amount of Burst Timing Error reported will change.

TX measurements should be disregarded when the Continuous Timing Advance control method is used. They may be made invalid by the access burst.

Related Topics


How to use Timing Advance Control.

CALL:(PDTCH|PDTChannel):MS:TADVance[:SELected]