ental redundancy (IR) Spreading factor (SF) 16, using UTRA (universal terrestrial radio access) OVSF (orthogonal variable spreading factor) channellisation codes Control channel approach Dedicated channel pointing to the shared channel Packet scheduling Fast scheduling done in Node B with 2 ms time basis; types: round-robin, proportional fair, fair throughput, Shared channel transmission Dynamically shared in the time and code domains Multiple-input multiple-output (MIMO) Optional; higher performance equipment sends channel quality reports to the base station at 2 ms intervals, which are used to adapt the modulation or resources accordingly. At layer 1, the hybrid automatic repeat request (HARQ) with a Stop and Wait (SAW) Protocol is used as a retransmission mechanism. Unlike the UMTS R99, the HARQ is processed directly in Node B, which allows a faster response, instead of being handled by the RNC. The fast scheduling feature is also implemented in Node B, compared to UMTS R99, where the scheduler is located in the RNC. The scheduler determines to which terminal the transmission in HSDSCH will be directed and, depending on the AMC, at what data rate. B.3.1 HSDPA Channels There are five different physical channels that are used by HSDPA services. HSDPA data are carried on HSPDSCH, which is a shared channel for all HSDPA users in the cell. There are two physical control MAC-d flow MAC-d MAC-d MAC-hs MAC-hs HS-DSCH HS-DSCH HS-DSCH HS-PDSCH Figure B.1 HSDPA protocol layers HSDPA Transport BlockSize Effective Code Rate (ECR) = Ch bits per TTI Where SF = 4 CPS.NM.STTI.BPSI Ch bits per TTI = CPS = ChipsPerSlot = 2560 SF = 16 NM = NrMulticodes =1 to 15 Reserved Typically 5 codes are STTI = SlotsPerTTI= Possible codes for allocated for HSDPA SF = SpreadingFactor = 16 multicode operation BPS = NrBitsPerSymbol = 2 or 4 Figure B.2 Code allocation for HSPDSCH and code rate estimation channels, one dedicated channel in uplink (HSDPCCH) and one shared channel in downlink (HSSCCH). In addition to these there are associated DPCHs