Termination Parameters
Last updated: July 24, 2008
The test set supports two mechanisms for terminating transmission of a Forward Link physical packet early:
Max Forward Packet Duration
When the
Forward Early Termination State
is set to Off, the
Max Forward Packet Duration
is used with the DRC value requested by the access terminal to determine how many slots are transmitted for the current forward link data packet. It can be thought as a manually emulation for the forward link early termination.
For each physical layer packet, the test set transmits
N
slots, where the
N
is defined as the minimum of the number of slots per DRC and the
Max Forward Packet Duration
. For the number of slots per DRC, see
FTAP Rate
for the subtype 0 physical layer and
DRC Value and Forward Transmission Formats
for the subtype 2 physical layer.
If you set the
Max Forward Packet Duration
to a value less than the actual slots required for the physical layer packet per the DRC value, the effective data rate will be higher than the nominal data rate per the DRC. For example, the nominal date rate for the DRC value 1 with packet format (physical layer packet size = 512 bits, nominal transmit duration =16 slots, preamble length =1024 chips) is 19.2kbps. If you set the to
Max Forward Packet Duration
to 4 slots, the effective data rate will be 76.8 kbps.
The
Max Forward Packet Duration
is applicable to both the Active Cell or IS-856 Test operating mode for all supported application types (see
Session Application Type
).
Forward Early Termination State
When the
Forward Early Termination State
is set to On, the transmission of the forward link packet will be terminated after any slot that the Reverse Ack Channel indicates an Ack (successful demodulation of the packet). Because Active Forward Link Early Termination is based on the Reverse Ack Channel, when and if a packet will early terminate varies from packet to packet and depends on the forward link quality.
The R-Ack Channel is transmitted by the AT to send an Ack or Nak. The test set will demodulate 3 states: Ack, Nak and None. The None state could happen when
-
there is no R-Ack Channel sent (no power detected)
-
a packet is not directed to the AT
-
the AT does not successfully demodulate the preamble of the a packet directed to the AT
-
the power in the R-Ack Channel is insufficient for the test set to demodulate the R-Ack Channel.
So when the
Forward Early Termination State
is set to On, the test set will stop transmission of a forward link packet if either of the following is true:
-
None is demodulated on R-Ack Channel for the first slot of a physical packet. A None received on any other slot of the physical packet will not stop transmission.
-
Ack is demodulated on the R-Ack Channel for that physical packet.
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