6B E-DCH related procedures

25.2143GPPPhysical layer procedures (FDD)Release 17TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

The following physical layer parameters are signalled to the UE from higher layers:

1) E-HICH set to be monitored for each uplink frequency for which E-DCH is configured

2) E-RGCH set to be monitored for each uplink frequency for which E-DCH is configured

If the UE is configured with multiple uplink frequencies, then the Secondary_EDCH_Cell_Enabled is 1, otherwise Secondary_EDCH_Cell_Enabled is 0 and Secondary_EDCH_Cell_Active is 0.

The Secondary_EDCH_Cell_Active shall be set according to the following rules:

– Secondary_EDCH_Cell_Active is set to 0 when Secondary_EDCH_Cell_Enabled is 0 or Secondary_Cell_Active is 0 (as described in subclause 6A.1).

– Secondary_EDCH_Cell_Active shall remain set to 0, when Secondary_EDCH_Cell_Enabled is changed from 0 to 1.

– Secondary_EDCH_Cell_Active shall be set to 0 or 1, upon the reception of HS-SCCH orders to deactivate or activate the secondary uplink carrier respectively as specified in [2] when Secondary_EDCH_Cell_Enabled is 1 and Secondary_Cell_Active is not 0 (as described in subclause 6A.1) and the 1^st secondary serving HS-DSCH cell is activated.

– Secondary_EDCH_Cell_Active shall be set to 0 or 1, upon the reception of HS-SCCH orders to deactivate or activate both the secondary uplink carrier and the 1^st secondary serving HS-DSCH cell as specified in [2] when Secondary_EDCH_Cell_Enabled is 1 (as described in subclause 6A.1).

– Secondary_EDCH_Cell_Active can be set to 0 by higher layers (as described in [5]).

Secondary_EDCH_Cell_Active shall be set to 1 while Secondary_EDCH_Cell_Enabled is 1, Secondary_Cell_Active is not 0,1^st secondary serving HS-DSCH cell is activated, and the secondary uplink frequency is activated, otherwise Secondary_EDCH_Cell_Active shall be set to 0. If the Secondary_EDCH_Cell_Active is already equal to 1 when the UE receives an HS-SCCH order for activation of the secondary uplink frequency as specified in [2], then the UE shall not change the status of Secondary_EDCH_Cell_Active regarding the contents of the order, but shall transmit the HARQ-ACK acknowledging the HS-SCCH order.

HS-SCCH ordered deactivation or activation of the secondary uplink frequency is applied by the UE at the same point in time as in the case of HS-SCCH ordered deactivation and activation of the secondary serving HS-DSCH cell for a UE configured with multiple uplink frequencies (see subclause 6A.1).

If higher layers set READY_FOR_COMMON_ERGCH to TRUE (as described in [5]) then Common_RGCH_Enabled is TRUE. Otherwise, Common_RGCH_Enabled is FALSE.

If higher layers configure concurrent deployment of 2ms and 10ms TTI in a cell (as described in [5]) then Concurrent_TTI_Deployment_Enabled is TRUE. Otherwise, Concurrent_TTI_Deployment_Enabled is FALSE.

If higher layers set READY_FOR_FALLBACK_R99_PRACH to TRUE (as described in [5]) then Fallback_R99_Enabled is TRUE. Otherwise, Fallback_R99_Enabled is FALSE.

If NT-HS-DPCCH_Enabled is TRUE, the UE shall inform higher layers about the reception of an HS-SCCH order and the order type.

6B.1 ACK/NACK detection

For each activated uplink frequency, the physical layer in the UE shall detect ACK or NACK within the E-HICH set that is monitored by the UE in the subframes where ACK/NACK is transmitted by the UTRAN and deliver the ACK/NACK to the higher layers as follows:

– When a UE is not in soft handover, an ACK shall be delivered to the higher layers if a reliable ACK is detected by the physical layer in the UE, else a NACK shall be delivered to the higher layers.

– When a UE is in soft handover, multiple ACK/NACKs may be received in an E-DCH TTI from different cells in the active set. In some cases, the UE has the knowledge that some of the transmitted ACK/NACKs are the same. This is the case when the radio links are in the same radio link set. For these cases, ACK/NACKs from the same radio link set shall be soft combined into one ACK/NACK information and delivered to higher layers. If a radio link set contains only one radio link, the detection shall be done as specified above for the case where the UE is not in soft handover. For each radio link set containing multiple radio links, an ACK shall be delivered to the higher layers if a reliable ACK is detected by the physical layer in the UE after soft combining, else a NACK shall be delivered to the higher layers.

6B.2 Relative grants detection

In CELL_DCH state, for each activated uplink frequency, the physical layer in the UE shall detect relative grants within the E-RGCH set that is monitored by the UE and deliver the relative grants to the higher layers as follows:

– When a UE is not in soft handover, an UP shall be delivered to the higher layers if a reliable UP is detected by the physical layer in the UE, else a DOWN shall be delivered to the higher layers if a reliable DOWN is detected by the UE, else a HOLD shall be delivered to the higher layers.

– When a UE is in soft handover, multiple relative grants may be received in an E-DCH TTI from different cells in the E-DCH active set. The UE shall handle the E-RGCH received from these cells as follows:

– If the E-DCH serving radio link set contains only one radio link, the detection shall be done as specified above for the case where the UE is not in soft handover. If the E-DCH serving radio link set contains more than one radio link, the relative grants from the E-DCH serving radio link set are the same and shall be soft combined into one single relative grant information; an UP shall be delivered to the higher layers if a reliable UP is detected by the physical layer in the UE after soft combining, else a DOWN shall be delivered to the higher layers if a reliable DOWN is detected by the UE after soft combining, else a HOLD shall be delivered to the higher layers.

– Furthermore, for each relative grant received from a radio link which does not belong to the E-DCH serving radio link set, a DOWN shall be delivered to the higher layers if a reliable DOWN is detected by the UE, else a HOLD shall be delivered to the higher layers. The UE shall not soft combine relative grants received from radio links which do not belong to the E-DCH serving radio link set.

In CELL_FACH state, if Common_RGCH_Enabled is TRUE, the physical layer in the UE shall detect relative grants within the E-RGCH set that is monitored by the UE and deliver the relative grants to the higher layers as follows:

– Multiple relative grants may be received in an E-DCH TTI from different cells that do not belong to the E-DCH serving radio link set. For each relative grant received from a cell, a DOWN shall be delivered to the higher layers if a reliable DOWN is detected by the physical layer in the UE, else a HOLD shall be delivered to the higher layers. The UE shall not soft combine relative grants received from any of the cells.

6B.2A Absolute Grant Detection when the UE is configured with Implicit Grant Handling

In CELL_DCH state, when Implicit Grant Handling is configured, the UE shall determine the presence of an E-AGCH transmission. If the presence of the E-AGCH transmission in an E-AGCH sub-frame is detected, then the Serving Grant Update procedure as described in subclause 11.8.1.3.1 of [9] shall be applied. Otherwise, the UE shall assume that it has not received an E-AGCH transmission in that TTI.

6B.3 E-DCH control timing

In subclauses 6B.3.1 and 6B.3.2 the word "first" refers to the earliest point in time.

6B.3.0 UE procedure for switching the E-DCH TTI length due to an HS-SCCH order

When Enhanced TTI switching is configured, upon successfully receiving an HS-SCCH order that depending on the UE’s configuration indicates single cell E-DCH TTI switching (i.e. from 2ms E-DCH TTI to 10ms E-DCH TTI or vice versa) or dual cell E-DCH TTI switching (see Table 14B.3B in [2]), the UE shall be able to start transmitting E-DCH data using the new E-DCH TTI length according to the activation time configured by higher layers and the time taken for E-DCH TTI reconfiguration. The activation time is measured from the beginning of the first E-DCH radio frame after the end of the HS-SCCH sub-frame containing the order. The UE E-DCH TTI reconfiguration process begins after the activation time and lasts for 20 ms, after which the UE shall be able to start transmitting E-DCH data using the new E-DCH TTI length.

6B.3.1 10 ms E-DCH TTI

For each cell in the E-DCH active set, the UE shall associate the control data received in the E-HICH frame associated with SFN i to the data transmitted in the E‑DPDCH frame associated with SFN i-3.

For each cell which belongs to the serving E-DCH radio link set, the UE shall first take into account E-DCH control data received in the E-RGCH frame associated with SFN i in the higher layer procedures which correspond to E-DCH transmission in the E-DPDCH frame associated with SFN i+1.

For each cell which does not belong to the serving E-DCH radio link set the UE shall first take into account E-DCH control data received in the E-RGCH frame associated with SFN i in the higher layer procedures which correspond to E-DCH transmission in the E-DPDCH frame associated with SFN i+1+s where:

The UE shall first take into account E-DCH control data received in the E-AGCH frame associated with SFN i in the higher layer procedures which correspond to E-DCH transmission in the E-DPDCH frame associated with SFN i+1+s where:

When a downlink F-DPCH is configured, .

6B.3.2 2 ms E-DCH TTI

For each cell in the E-DCH active set, the UE shall associate the E-DCH control data received in sub-frame j of the E-HICH frame associated with SFN i to sub-frame t of the E‑DPDCH frame associated with SFN i-s where:

, and

For each cell which belongs to the serving E-DCH radio link set, the UE shall first take into account E-DCH control data received in sub-frame j of the E-RGCH frame associated with SFN i in the higher layer procedures which correspond to E-DCH transmission in sub-frame j of the E-DPDCH frame associated with SFN i+1.

For each cell which does not belong to the serving E-DCH radio link set the UE shall first take into account E-DCH control data received in the E-RGCH frame associated with SFN i in the higher layer procedures which correspond to E-DCH transmission in sub-frame t of the E-DPDCH frame associated with SFN i+1+s where:

, and

The UE shall first take into account E-DCH control data received in sub-frame j of the E-AGCH frame associated with SFN i in the higher layer procedures which correspond to E-DCH transmission in sub-frame t of the E-DPDCH frame associated with SFN i+s where:

, and

The same relationship applies for E-ROCH to S-E-DPDCH timing relationship as is defined above for the E-AGCH to E-DPDCH timing relationship.

When a downlink F-DPCH is configured, .

6B.4 Operation during compressed mode

6B.4.1 Uplink compressed mode

When E‑DCH TTI length is 2 ms, the UE shall not transmit E‑DCH data in a TTI which fully or partly overlaps with an uplink transmission gap.

Handling of uplink compressed mode when the E-DCH TTI is 10msec is described in [2].

6B.4.2 Downlink compressed mode

The following applies for the UE for reception of E-HICH, E-RGCH and E-AGCH, during compressed mode on the DPCH or F-DPCH:

– A UE shall decode E-HICH, E-RGCH, E-ROCH or E-AGCH transmissions to the UE using all the slots which do not overlap a downlink transmission gap.

– The UE may discard E-HICH, E-RGCH, E-ROCH or E-AGCH slots which overlap a downlink transmission gap.