HSDPA Overview

1
HSDPA Overview

• By
• Syed Asif Hussain Shah
• Mohammad Reza Akhavan
• 10th March, 2005
• Networking Project

2
Agenda

• High Speed Downlink Packet Access (HSDPA)
• Major work item for Release 5 in 3GPP
• HSDPA provides impressive enhancements over WCDMA
  for the downlink
• WCDMA 2 Mbps ? HSDPA 14 Mbps (with MIMO 20)
• UMTS network architecture

3
UMTS Network Architecture
Uu
Iu PS
Iub
GGSN
SGSN
IP Networks
Iur
Gi
Gn
Core Network
UE
Node B
UTRAN

• UMTS Universal Mobile Telecommunications System
• UTRAN UMTS Terrestrial Radio Access Network
• UE User Equipment
• RNC Radio Network Controller
• RNS Radio Network Subsystem (RNC Bs)
• SGSN Serving GPRS Service Node
• GGSN Gateway GPRS Service Node

4
HSDPA features...

• Reduction of information frame
• Feedback of reception quality (CQI)
• Adding new features
• 3 Channels
• HARQ
• AMC
• MIMO
• FCS

5
HSDPA Channels

• High Speed Physical Downlink Shared Channel
  (HS-PDSCH)
• HS-Downlink Shared Channel (HS-DSCH)
• HS-Shared Control Channel (HS-SCCH)
• High Speed Dedicated Physical Control Channel
  (HS-DPCCH)

HS-DPCCH CQI
HS-SCCH DL Transfer Information
HS-DSCH Data Transfer
HS-DPCCH, ACK, NACK
6
HS - Downlink Shared Channel (HS-DSCH)

• Shared channel transmission

7
AMCAdaptive Modulation Coding

• Modulation coding depends on channel quality
  condition
• Modulation Schemes
• QPSK
• 16QAM
• Different Code Rates used

8
H-ARQHybrid Auto Repeat reQuest

• Provide Link Layer Retransmissions
• Moved From RNC to Node-B
• Use two Schemes Chase Combing and Incremental
  Redundancy

9
MIMOMultiple Input Multiple Output

• Is based on multipath environment
• Used just in downlink
• Used in further away from the base station

10
Fast cell site selection (FCS)

• Tracking of active set of Node Bs connected to a
  UE
• Operate by monitoring SIR (Signal-to-Interference
  Rate) level of all Bs
• Selection of the Node-B with the best current
  transmission characteristics
• High data rates can be achieved

11
Any Questions Comments ?

• ?