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TR 25.872

High Speed Packet Access (HSDPA) multipoint transmission

TopIndexPrevNext ToC3GPP-page 
- - - - - - - - v11.0
29 p.
 - - - -
after the TSG Plenary Meetings, the 3GPP produces Word documents and afterwards the ETSI publishes the PDF versions
Rapporteur:   RANTA-AHO, Karri
See also:   –
HSPA based mobile internet offerings are becoming very popular and data usage is increasing rapidly. Consequently, HSPA has begun to be deployed on more than one transmit antenna or more than one carrier. As an example, the single cell downlink MIMO (MIMO-Physical layer) feature was introduced in Release 7.

This feature allowed a NodeB to transmit two transport blocks to a single UE from the same cell on a pair of transmit antennas thus improving data rates at high geometries and providing a beamforming advantage to the UE in low geometry conditions. Subsequently, in Release-8 and Release-9, the dual cell HSDPA (DC-HSDPA) and dual band DC-HSDPA features were introduced.

Both these features allow the NodeB to serve one or more users by simultaneous operation of HSDPA on two different carrier frequencies in two geographically overlapping cells, thus improving the user experience across the entire cell coverage area. In Release 10 these concepts were extended so that simultaneous transmissions to a single UE could occur from four cells (4C-HSDPA).

When a UE falls into the softer or soft handover coverage region of two cells on the same carrier frequency, it would be beneficial for the non-serving cell to be able to schedule packets to this UE and thereby improving this particular user’s experience, especially when the non-serving cell is partially loaded. MultiPoint HSDPA allows two cells to transmit packets to the same UE, providing improved user experience and system load balancing. MultiPoint HSDPA can operate on one or two frequencies.
full Table of Contents for Word version:   11.0
 1Scope       p. 6Top
 2References       p. 6Top
 3Definitions, symbols and abbreviations       p. 6
3.1Definitions       p. 6
3.2Symbols       p. 7
3.3Abbreviations       p. 7
 4Objectives of the HSDPA Multipoint Transmission Study       p. 7Top
 5Descriptions of the HSDPA Multipoint Transmission Concepts       p. 8
5.1Single point data transmission       p. 8
5.1.1HS-DDTx       p. 8
5.1.2SF-DC Switching       p. 8
5.1.3DF-4C Switching       p. 8
5.2Multiflow data transmission       p. 9
5.2.1SF-DC Aggregation       p. 9
5.2.2DF-DC Aggregation       p. 9
5.2.3DF-4C Aggregation       p. 10
5.3Single Frequency Network data transmission       p. 10
5.3.1HS-SFN       p. 10
 6Evaluation Methodology       p. 11
6.1System Simulation Assumptions       p. 11
6.2System Performance Evaluation Metrics       p. 16
6.2.1Metrics without modeling RLC or Iub flow control       p. 16
6.2.2Additional metrics with RLC or Iub flow control modeled       p. 16
 7Evaluation Results       p. 16Top
 8Impact on Implementation       p. 17
8.1Impact on Infrastructure Implementation       p. 17
8.2Impact on UE Implementation       p. 17
8.2.1Impact on UE implementation due to asynchronous cell
timings       p. 17
8.2.2Impact on UE Implementation due to SF-DC switching       p. 18
8.2.3Impact on UE Implementation due to SF-DC and DF-DC
aggregation       p. 19
8.2.4Impact to synchronization function of the secondary serving
HS-DSCH cell       p. 21
8.2.5Summary of Impact on UE Implementation       p. 21
 9Higher layer impact       p. 22
9.1Overview       p. 22
9.2Intra-site Multiflow data split       p. 23
9.3Inter-site Multiflow data split       p. 23
9.3.1RLC split       p. 23
9.3.2PDCP split       p. 25
 10Impact on performance of legacy UEs       p. 26Top
 11Impact on specifications       p. 27
11.1Impact on RAN1 specifications       p. 27
11.2Impact on RAN2 specifications       p. 27
11.3Impact on RAN3 specifications       p. 28
11.4Impact on RAN4 specifications       p. 28
 11aConclusion       p. 28Top
Annex AChange history       p. 29Top