For the purposes of the present document, the terms and definitions given in TR 21.905 and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905. Power saving mode:

For the purposes of the present document, the following symbols apply:

For the purposes of the present document, the abbreviations given in TR 21.905 and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in TR 21.905. ACDC ANDSF DPCCH2 NCL NR OPI PSM SRVCC QoE WLAN

This sub-feature introduces new DL DPCH slot format by removing the dedicated pilot bits from DL DPCCH and reusing them for DL DPDCH instead. The R99 downlink physical channel (DPCH) consists of 0.66ms slots that contain 2 groups of data (DPDCH) symbols and 3 groups of control (DPCCH) symbols. The size of the groups is determined by the slot format. The control symbol groups are TPC - controlling uplink transmit power, TFCI - specifying the downlink packet type, and dedicated pilot - supporting channel estimation for DL power control and closed-loop transmit diversity. While the TFCI group may be empty in certain slot formats, the pilot and TPC are currently always non-empty. The dedicated pilot bits are used for estimation of DL SIR. With this sub-feature, new DL DPCH slot formats are introduced by removing the dedicated pilot bits and reusing the TPC bits instead for estimating the DL SIR. Correspondingly, the number of data symbols in a slot is increased leading to less control channel overhead on the downlink. DL closed-loop transmit diversity is not supported when this sub-feature is configured.

The physical layer in R99 is designed to carry potentially a large variety of transport blocks with different sizes. The drawback for this design is the rate matching may not be efficient when some transport format combinations are not frequently used. For example, DCCH channel carries non-zero transport blocks not as often as voice DTCH channel. The enhanced rate matching and transport channel multiplexing sub-feature sets a zero rate matching attribute for DCCH, whenever DCCH channel does not carry a transport block together with DTCH channel. The DCCH bit fields are used to transmit DTCH transport channels instead. This potentially improves link efficiency due to less puncturing and better rate matching of the transport block with the available physical channel resources.

In a power-controlled system such as R99 DCH, inefficiencies in the power-control loop, such as limited granularity, delays and errors in the feedback, result in the presence of excess SINR at the receiver. This means that packets such as the voice packets which have a long (20ms) transmission time interval (TTI) can often be early-decoded, i.e, decoded prior to reception of all the data symbols in a TTI by running the channel decoder at multiple time instants during the TTI instead of only once at the end of the TTI. This is referred to as Frame Early Termination (FET). As described below, DCH enhancements introduces new mechanisms to R99 DCH in order to support DL FET. A new design of UL DPCCH is introduced to support DL FET. With the new design, TFCI information is carried in the first 10 slots of each 20ms TTI for the uplink. Sending the TFCI information early in each 20ms TTI allows sending of DL FET ACK or NACK information using the TFCI bits in remaining UL DPCCH slots that do not carry TFCI. Furthermore, there are two modes of operation introduced with support for DL FET in DCH enhancements as described below.

The R99 DCH transport channels for a voice call are typically configured with 20ms TTI. However, the transport block sizes for a voice call could potentially be transmitted over a shorter duration. The sub-feature of uplink DPDCH dynamic 10ms transmission allows for dynamically selecting a shorter transmission time, i.e. 10ms, at the physical layer to transmit a voice packet on the uplink. The UE selects on whether to use a 10ms or 20ms transmission duration based on considerations such as the power headroom at the UE. The UE also discontinues the transmission of UL DPCCH for the remaining duration of the TTI when both UL transport block has been completed transmitted and DL has been successfully decoded early. With 20ms TTI transmission at the physical layer, the pilot channel (UL DPCCH) is sent for the entire 20ms duration. This sub-feature potentially improves link efficiency due to reduction in UL DPCCH overhead as well as improves UE battery performance by allowing the UE to turn off its transceiver once the reception and transmission has been completed before the end of a 20ms TTI.

In CELL_DCH state, it allows the network to indicate to the UE about the DSAC and PPAC parameters through dedicated signalling so that the UE can obtain the updated DSAC and PPAC information.

In order to increase system information capacity (see TR 25.704) a second system information broadcast channel on SCCPCH can be configured, in addition to the system information broadcast channel on PCCPCH. The second system information broadcast channel is mapped to a separate SCCPCH, which is different from the SCCPCH used for paging and FACH/CTCH, as depicted in Figure 9.1-1.

The UE should be able to monitor at least two SCCPCHs simultaneously, but the UE may skip reading the second system information broadcast channel during CTCH occasions in Idle mode and CELL_PCH/URA_PCH state. When HS-DSCH in CELL_FACH is used, a UE supporting second system information broadcast channel monitors the corresponding SCCPCH while listening to HS-DSCH. REL-12 and later SIBs are introduced on both the system information broadcast channel as well as the second system information broadcast channel. Pre-REL-12 SIBs may be broadcasted on the second system information broadcast channel in addition to the system information broadcast channel. Any SIB type may be scheduled simultaneously on system information broadcast channel and second system information broadcast channel provided that the content is the same. Most of the existing principles and procedures for system information reading are retained for the second system information broadcast channel. To reduce the latency to acquire the system information on both system information broadcast channel and second system information broadcast channel, the UE acquires the system information on both channels simultaneously. The simultaneous acquisition of system information on both system information broadcast channel and second system information broadcast channel is depicted in Figure 9.1-2.

When the SB3 value tag in PAGING TYPE 1 or SYSTEM INFORMATION CHANGE INDICATION (SICI) message is updated the UE supporting second system information broadcast channel is required to re-acquire the system information on the second system information broadcast channel. When the SB3 value tag is updated, but the MIB value tag is not, the UE supporting second system information broadcast channel is only required to re-acquire the system information on the second system information broadcast channel. The scheduling block 3 (SB3) contains the scheduling information for the system information on the second system information broadcast channel. This scheduling information uses the SFN of the PCCPCH. The SB3 is broadcasted with a pre-defined offset (40 ms) from the start of the frame containing the MIB, as depicted in the Figure 9.1-3. The MIB on BCH mapped on PCCPCH contains the channelization code of the second system information broadcast channel, the repetition interval of SB3 and the number of segments of SB3. The remaining configuration parameters of the second system information broadcast channel are pre-defined.

To reduce the overhead of SIB scheduling information, included in MIB and Scheduling Blocks, the network may use mandatory default values for SIB_OFF and SEG_COUNT (when SIB_POS offset info is included) for SIBs of REL-12 or later.

To reduce the risk of Cell Value Tag wrap around, the network may broadcast a range extension (1..16) of the Cell Value Tag for SIB3, SIB5, SIB5bis, SIB21 and SIB22. The network may also extend the MIB value tag range (1..16). For UEs supporting these extensions the SIBs and MIB wrap around at 16, while for UEs not supporting this feature the SIBs wraps around at 4 (and MIB at 8). SIBs of REL-12 or later use the extended Cell Value Tag range (1..16).

This version of the specification supports UTRAN assisted UE based bi-directional traffic steering between UTRAN and WLAN for UEs in Idle mode and CELL_DCH, CELL_FACH, CELL_PCH and URA_PCH states. UTRAN provides assistance parameters via broadcast and dedicated RRC signalling to the UE. The RAN assistance parameters may include UTRAN signal strength thresholds, WLAN channel utilization thresholds, WLAN backhaul data rate thresholds, WLAN signal strength thresholds and Offload Preference Indicator (OPI). UTRAN can also provide a list of WLAN identifiers to the UE via broadcast and dedicated signalling. The UE uses the RAN assistance parameters in the evaluation of:

• access network selection and traffic steering rules defined in TS 25.304; or
• ANDSF policies defined in TS 24.312

for traffic steering decisions between UTRAN and WLAN as specified in TS 23.402. The OPI is only used in ANDSF policies as specified in TS 24.312. WLAN identifiers are only used in access network selection and traffic steering rules defined in TS 25.304. If the UE is provisioned with ANDSF policies it shall forward the received RAN assistance parameters to upper layers, otherwise it shall use them in the access network selection and traffic steering rules defined in subclause 10.2 and TS 25.304. The access network selection and traffic steering rules defined in subclause 10.2 and TS 25.304 are applied only to the WLANs of which identifiers are provided by the UTRAN. The UE in CELL_DCH state shall apply the parameters obtained via dedicated signalling, and shall keep those parameters during handover if they are not reconfigured or deleted; the UE shall discard the parameters obtained via dedicated signalling at SRNS relocation. The UE in CELL_FACH state shall apply the parameters obtained via dedicated signalling if such have been received from the serving cell; otherwise the UE shall apply the parameters obtained via broadcast signalling. Upon cell selection/reselection the UE shall discard the dedicated parameters. The UE in Idle mode, CELL_PCH or URA_PCH state shall keep and apply the parameters obtained via dedicated signalling until selection/reselection of another cell than the one where these parameters were received or a timer has expired since the UE moved from CELL_DCH or CELL_FACH to Idle mode, CELL_PCH or URA_PCH state, upon which the UE shall discard the dedicated parameters and apply the parameters obtained via broadcast signalling. In the case of RAN sharing, each PLMN sharing the RAN can broadcast independent sets of RAN assistance parameters.

The UE indicates to upper layers when (and for which WLAN identifiers) access network selection and traffic steering rules defined in TS 25.304 are fulfilled. The selection among WLANs that fulfil the access network selection and traffic steering rules is up to UE implementation. When the UE applies the access network selection and traffic steering rules defined in TS 25.304, higher layers perform traffic steering between UTRAN and WLAN.

The retrievable configurations feature allows the UE to store configurations together with an identity. When the network invokes a retrievable configuration, it needs to signal only its identity. A retrievable configuration can be signalled to a UE in any state except for idle. Retrievable configurations are cleared when entering idle mode and at SRNS relocation. There are two ways of signalling the retrievable configurations: one way is that as a result of an RRC signalling procedure, the UE stores the received configuration as a retrievable configuration, and the other way is that the network preconfigures the UE with at least one retrievable configuration. The network can signal a delta to a stored configuration for either of the two ways. The UE validates a retrievable configuration when it invokes it.

The feature URA_PCH with seamless transition to CELL_FACH is described in TS 25.319.

If the UE supports "NodeB triggered HS-DPCCH transmission", the RNC can issue the indication to trigger acquisition of the common E-DCH resource or to release the allocated common E-DCH resource for the particular UE.

The feature blind HARQ retransmissions for HSDPA is described in TS 25.308.

This feature allows the UE to move to a more power efficient state without explicit RRC reconfiguration. The UE sends the RRC indication to the RNC and moves to the target state upon reception of the RLC ACK from the RNC. The state transition is applicable to the following cases: from CELL_DCH to CELL_FACH, from CELL_FACH to CELL_PCH/URA_PCH, and from CELL_DCH to CELL_PCH/URA_PCH. While configuring a UE with enhanced state transition, the RNC can provide RRC configuration that will be applied once the UE enters the target state.

In improved synchronized RRC procedures, firstly the UE receives an RRC reconfiguration message for a synchronized RRC procedure indicating that the activation time shall be dynamically determined. Then, when the UE is ready to switch to the new configuration indicated in the RRC message, it sends a MAC Control Information to the Node B. On reception of the HARQ ACK to the MAC Control Information, the UE calculates the activation time by adding an offset to the current CFN. The UE reconfigures at the calculated activation time and sends an RRC configuration complete message upon successful completion of the procedure. The network can also indicate a legacy activation time, at which the switch to the new configuration latest shall occur. The UE will choose the smallest value of the legacy activation time and the calculated activation time as the final activation time.

The RRC measurement events for UPH reporting allow the UE to perform measurements on UE Power Headroom (UPH) and signal measurement events when the UPH becomes larger or less than an absolute threshold respectively. The thresholds are configurable, as well as hysteresis, time-to-trigger, filter coefficient and pending time after trigger for each of the events.

The simultaneous setup and release of RABs and RBs enhancement allows setup, release and reconfiguration of radio access bearers and radio bearers in the same RRC message.