ACK R-Data After

ACK R-Data After

Last updated: January 16, 2009

This section is only applicable to the lab application and to a test application with the required feature license.

ACK R-Data After setting is used to emulate early termination on the reverse data channel (R-Data). It determines when the test set starts to send ACK bit on the forward ARQ channel upon reception of the R-Data subpackets.

ACK R-Data After setting is applicable when the test set is in the Active Cell operating mode with current physical layer subtype set to Subtype 2 (see Release A Physical Layer Subtype ) and the Active ARQ disabled (see Fixed Settings ).

In Subtype 2 physical layer operation, the AT can transmit up to four subpackets for each transmitted physical layer packet (see Background Information (Subpacket) ). The test set transmits a positive acknowledgment (ACK) or a negative acknowledgment (NAK) on the ARQ Channel in response to each received subpacket.

The following table shows the ACK/NAK bit patterns that are transmitted by the test set on the forward ARQ channel according to the ACK R-Data After setting and the actual received reverse data subpackets.

Bit pattern sent on the forward ARQ channels
ACK R-Data After ARQ Bits Sent after Reverse Traffic Subpacket N Is Received Overall Packets
(P-ARQ)

Subpacket 0

Subpacket 1

Subpacket 2

Subpacket 3

H-ARQ

H-ARQ

H-ARQ

L-ARQ

Subpacket 0 (All ACK) ACK ACK * ACK * ACK * ACK
Subpacket 1 NAK ACK ACK * ACK * ACK
Subpacket 2 NAK NAK ACK ACK * ACK
Subpacket 3 NAK NAK NAK ACK ACK
Never (All NAK) NAK NAK NAK NAK NAK

Note:

* ACK is sent only if the subpacket is received. The AT is not expected to send the subpacket if it correctly demodulates and processes the previously received ACK for that physical layer subpacket.

When Subpacket 0 (All ACK) is selected, an ACK bit will be sent on the ARQ channels for every subpacket received. When Never (All NAK) is selected, an NAK bit will be sent on the ARQ channels for every subpacket received.

ACK R-Data After setting defaults to Never (All NAK) which is to force the AT listening to the ARQ channel to send all four subpackets for each physical layer packet.

Different modulation schemes are used on the ARQ channel. The L-ARQ bit and the P-ARQ bit are modulated using NAK-oriented ON-OFF Keying (0 implies ACK, -1 implies NAK) while the H-ARQ modulation depends upon the setting of H-ARQ Modulation .

Related Topics


GPIB Command:

Manual Operation: How Do I Change Generator Information? (Termination Parameters menu)

R-Data Pkt Size

Release A Physical Layer Subtype

Enhanced Test Application Protocol