AT Directed Packets

AT Directed Packets

Last updated: May 24, 2006

3GPP2 C.S0033-A section specifies :

When the access terminal under test is in the Connected State and a 100% packet activity is required (see Fixed Settings , Forward Packet Activity), the access network equipment shall conform to the following rules for the generation of packets:

The test set implements this requirement but allows for the percentage of packets directed to the AT under test to be varied. The AT Directed Packets specifies what percentage of the packets are directed to the AT under test. This parameter can be set between 0 and 100%, in 1% increments. The default value is 50%. The AT Directed Packets is displayed on the Call Setup screen in the Application Configuration window.

If the AT under test has enough processing power to receive more than 50% of the valid FTAP or FETAP test packets, you can increase the AT Directed Packets parameter and speed up PER testing, optimizing throughput. For more description on the FTAP or FETAP, see C.S0029 Test Application Specification Description (TAP/ETAP) .

If Limited TAP is on while Test Application Protocol is set to FTAP, AT Directed Packets must not be greater than 50%, and RTAP Rate must be set to 9.6 kbps.


In order for the R-ACK Channel to be active, you must set ACK Channel Bit Fixed Mode Attribute to on, and set AT Directed Packets to a non-zero value.

Operating Considerations ( Lab Application Only )

In the Lab Application , when the Session Application Type is set to the Default Packet Application , the AT Directed Packets will determine the maximum percentage of Forward Traffic Channel packets that will be directed to the AT.

  • You should always set the AT Directed Packets to 100% for maximum throughout. This allows the test set to send data to the AT under test in all possible slots. Note that achieving maximum throughout also depends on other parameters of your test setup such as Window Size, TCP or UDP protocol, etc.
  • When there is no data or not sufficient amounts of data to send to the AT, the actual percentage directed to the AT will be lower that the AT Directed Packets setting.

Related Topics

Programming: Programming a Packet Error Rate (PER) Measurement

GPIB Command: CALL[:CELL]:APPLication:ATDPackets

Manual Operation: How Do I Change Call Parameters?

Packet Error Rate (PER) Measurement Description

C.S0029 Test Application Specification Description (TAP/ETAP)