HSUPA Category Definitions and Data Rates
- a summary of the different HSUPA categories, the HSUPA category definitions and the different data rates.
In order to be able to cater for a number of variations in the level to which HSUPA is implemented, a number of different HSUPA categories have been defined. These HSUPA categories are equivalent in function to those used on the downlink, althought he actual parameters and speeds are naturally different.
The HSUPA categories allow for different levels of performance within the UE. The characteristics of the UE can then be easily communicated to the network which can then communicate with it in a suitable manner.
HSUPA category definitions
The HSUPA categories are detailed in the table below. This shows the different HSUPA categories with their data rates, and other required parameters.
|HSUPA category number||Maximum number E-DPDCHs||Minimum spreading factor||Support for 2 ms TTI*||Maximum transport block size
(10 ms TTI)
| Maximum transport block size
(2 ms TTI)
| Maximum data rate
|4||2||SF2||Y||20000||5837||2 Mbps for 10 ms TTI
2.9 Mbps for 2 ms TTI
|6||2 + 2**||SF2||Y||20000||11520||2 Mbps for 10 ms TTI
5.74 Mbps for 2 ms TTI
*A 10 ms TTI is supported in all categories
** Two E-DPDCHs at SF2 and two at SF4
Support for the E-DCH TTI (Transmission Time Interval) of 10 ms is required for all HSUPA categories. It is only some HSUPA categories that support a 2 ms TTI. Also the highest data rate supported with a 10 ms TTi is 2 Mbps. The reason for this is to limit the amount of buffer memory required in the NodeB for soft combining because a larger block transport size means that a larger soft buffer is needed for retransmissions.
By Ian Poole
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