ghest data rate it can accept under the current channel conditions while still maintaining a controlled block error rate (i.e. under 10 %). This CQI (channel quality indication) is signalled through the HSDPCCH. The network uses this in order to reconfigure the HSDSCH format for subsequent transmission to that UE. For example, if the CQI shows that the quality is degrading, the sched- uler can choose a less aggressive coding/modulation format that will cope better with the poor conditions. Typically the link adaptation is divided into two phases, known as the inner loop and outer loop algorithms: Inner loop algorithm. This takes the decision for the modulation and coding scheme to be used in the next TTI. This selection will be done only for new transmissions (i.e. not for retransmissions), and will be based on the received CQI, the available HSDSCH transmit power, the number of HSPDSCH codes, the RLC PDU size, input from the outer loop HSDSCH algorithm and the UE category. It is important that input parameters (CQI reports and DPCH power measurements) to the inner loop algorithm are subject to a minimum delay, because otherwise the LA would not be able to track fading in the radio channel properly. Outer loop algorithm. The primary goal is to compensate any bias introduced by the inner loop algorithm. This bias might be introduced due to offsets in relative UE performance, due to improved receiver architecture, etc. Typically, the outer loop may be based on the BLER target obtained from RLC ACK/NACK information, but also the CQI may be used directly. B.3.4 Error Correction (HARQ) Layer 1 retransmissions expand the system recovery capability from air transmission errors, and are subject to significantly shorter delays than RLC retransmissions, due to the closeness of UE and Node B (See the MAC layer split in Table B.1). This results in lower delay jitter, which can be very beneficial for data services based on TCP or streaming applications. Figure B.3 shows the different retransmission layers in the HSDPA archite