Serving Grant

Last updated: January 15, 2009

This section is only applicable to the lab application or feature-licensed test application.

To change the UE's serving grant while on a connection you can send a single shot or pattern absolute grant on the E-AGCH, perform a Transport Channel Reconfiguration (see TCR Absolute Grant ) or send the UE up/down commands on the E-RGCH.

Relative Grant Transmission

The test set can only transmit to the UE on the E-RGCH when it knows the UE will act on the command. Thus, the test set maintains a FIFO (First-In-First-Out) queue of relative grant commands that are transmitted on the E-RGCH as opportunities arise (the test set transmits using the alternate E-RGCH signature in all other E-RGCH frames, which signifies a "Hold" to the UE under test, see HSPA Downlink Channel Details ). At each transmission opportunity, the oldest relative grant command is removed from the relative grant queue and transmitted to the UE on the E-RGCH. Note that queued relative grant commands are not collapsed by the test set (in other words, two "Up" commands followed by one "Down" command are not transmitted as a single "Up"; the test set transmits every relative grant command).

According to 3GPP TS 25.321 s11.8.1.3.1, the UE will only act on a relative grant command if all of the following are true:

• The current serving grant is not set to ZERO_GRANT.
• The UE has not received a new absolute grant within 1 HARQ Round Trip Time (40 ms for 10 ms TTI, 16 ms for 2 ms TTI).
• The UE was expecting to receive an ack/nack on the E-HICH at the same time as the network sent the E-RGCH command (an ack/nack sent for a E-DPDCH transmission that just contained MAC-e Scheduling Information alone does not meet this criteria).

Thus, the test set will only transmit a relative grant command on the E-RGCH during a TTI that also includes an ack/nack on the E-HICH (for a block that does not consist of only Scheduling Information) and if the most recent E-AGCH transmission occurred more than 40 ms ago and the most recent absolute grant command was not ZERO_GRANT. Note that when AG Mode is set to Pattern , the E-AGCH is transmitted continuously unless one or more of the pattern values is set to DTX (Alt E-RNTI) , thus causing all relative grant commands to be queued.

The relative grant queue is reset to empty when the connection is ended (or if the connection changes to a non-HSPA connection), or when the Clear Queued Relative Grants action is initiated.

The relative grant queue holds up to 1000 relative grant commands; any additional commands are discarded and an error is posted. You can determine how many relative grant commands are in the queue using the Queued Relative Grants result.

Serving Grant Parameters

• AG Mode

  The test set supports two modes of operation on the E-AGCH, Single Shot and Pattern .

  • When AG Mode is set to Single Shot , when you initiate the Send Single Shot AG action the Single Shot AG absolute grant value is sent to the UE.
  • When AG Mode is set to Pattern , the test set transmits constantly on the E-AGCH using a repeating pattern of two absolute grant values, Absolute Grant Pattern - Value 1 and Absolute Grant Pattern - Value 2 . These absolute grant values are alternately sent every TTI (10 ms). Upon transition to the Pattern state, Absolute Grant Pattern - Value 1 is always the first value transmitted on the E-AGCH, always on an even SFN. Upon transition away from the Pattern state (to Single Shot ), the last value sent to the UE is indeterminate as the transmission of the pattern is ended immediately. Note that when AG Mode is set to Pattern the E-AGCH is transmitted continuously to the UE (unless one or more of the pattern values is set to DTX (Alt E-RNTI) ), thus causing all relative grant commands to be queued (see Relative Grant Transmission ).

  GPIB command: CALL:HSUPa:SGRant:ABSolute:MODE

• Single Shot AGThis setting determines the next absolute grant sent to the UE on the E-AGCH when the Send Single Shot AG action is initiated ( AG Mode must be set to Single Shot ). The UE interprets this value according to the table in 3GPP TS 25.212 s4.10.1A.1.

  GPIB command: CALL:HSUPa:SGRant:ABSolute:SSHot[:VALue]

• Send Single Shot AG

  This action causes the test set to immediately transmit the current value of the Single Shot AG setting to the UE on the E-AGCH (when AG Mode is set to Single Shot and an HSPA connection is active). The value is only transmitted over a single TTI and has a scope of "All HARQ Processes" (the only legal value when 10 ms TTI is used). If the absolute grant is to be sent during the same frame as a relative grant then the absolute grant is sent and the relative grant is pended (see Relative Grant Transmission ).

  GPIB command: CALL:HSUPa:SGRant:ABSolute:SSHot:SEND[:IMMediate]

• Send Relative Grant Up

  This action instructs the test set to transmit an "Up" relative grant command to the UE. The command is transmitted by the test set at the first available opportunity, or added to the relative grant queue if other relative grant commands are already pending (see Relative Grant Transmission ).

  By default there is no power present in the E-RGCH ( HSPA Cell 1 Connected E-RGCH Level is set to Off by default). If you initiate this action when HSPA Cell Connected E-RGCH Level is set to Off , a warning is posted but the relative grant command is still transmitted/queued.

  The UE only listens to the E-RGCH if RB Test Mode E-RGCH Information State was set to On when the connection was established (it is set to Off by default). Thus, this action is rejected if RB Test Mode E-RGCH Information State is Off .

  For HSPA PS data connections, the UE only listens to the E-RGCH if PS Data E-RGCH Information State was set to On when the connection was established (it is set to On by default). Thus, this action is rejected if PS Data E-RGCH Information State is Off .

  GPIB command: CALL:HSUPa:SGRant:RELative:UP:SEND[:IMMediate]

• Send Relative Grant Down

  This action instructs the test set to transmit a "Down" relative grant command to the UE. The command is transmitted by the test set at the first available opportunity, or added to the relative grant queue if other relative grant commands are already pending (see Relative Grant Transmission ).

  By default there is no power present in the E-RGCH ( HSPA Cell 1 Connected E-RGCH Level is set to Off by default). If you initiate this action when HSPA Cell Connected E-RGCH Level is set to Off , a warning is posted but the relative grant command is still transmitted/queued.

  For HSPA RB test mode connections, the UE only listens to the E-RGCH if RB Test Mode E-RGCH Information State was set to On when the connection was established (it is set to Off by default). Thus, this action is rejected if RB Test Mode E-RGCH Information State is Off .

  For HSPA PS data connections, the UE only listens to the E-RGCH if PS Data E-RGCH Information State was set to On when the connection was established (it is set to On by default). Thus, this action is rejected if PS Data E-RGCH Information State is Off .

  GPIB command: CALL:HSUPa:SGRant:RELative:UP:SEND[:IMMediate]

• RB Setup AG

  This setting controls the serving grant that the UE is given during call setup in the RB Setup message. This serving grant is specified in terms of the 3GPP TS 25.321 s9.2.5.2.1.1 Scheduling Grant Table (and is not determined by the 3GPP TS 25.212 s4.10.1A.1 table that is used to communicate absolute grants on the E-AGCH). It is set to the highest possible value by default to give the UE full access to the entire uplink.

  GPIB command: CALL:HSUPa:SGRant:ABSolute:RBSetup[:VALue]

  This setting can only be changed when the connection status is idle.

• AG Pattern Parameters
  • Absolute Grant Pattern - Value 1

    This setting determines the first value in the pattern of absolute grants sent to the UE on the E-AGCH when AG Mode is set to Pattern . This value is sent to the UE on even SFNs. If Absolute Grant Pattern - Value 1 is set to DTX (Alt E-RNTI) , the test set still transmits this absolute grant value on even SFNs, but it uses the Alternate E-RNTI (Hex) (thus appearing to the UE as if the E-AGCH was DTX'd during this frame).

    GPIB command: CALL:HSUPa:SGRant:ABSolute:PATTern:VALue[1]

    This setting cannot be changed when AG Mode is set to Pattern .

  • Absolute Grant Pattern - Value 2

    This setting determines the second value in the pattern of absolute grants sent to the UE on the E-AGCH when AG Mode is set to Pattern . This value is sent to the UE on odd SFNs. If Absolute Grant Pattern - Value 2 is set to DTX (Alt E-RNTI) , the test set still transmits this absolute grant value on odd SFNs, but it uses the Alternate E-RNTI (Hex) (thus appearing to the UE as if the E-AGCH was DTX'd during this frame).

    GPIB command: CALL:HSUPa:SGRant:ABSolute:PATTern:VALue2

    This setting cannot be changed when AG Mode is set to Pattern .

• Clear Queued Relative Grants

  Clears the relative grant queue.

  GPIB command: CALL:HSUPa:SGRant:RELative:QUEued:CLEar