HSPA/HSDPA(Beyond 3G)

PRESENTED BY-Manish Srivastava

High Speed Packet Access (HSPA) is an amalgamation of two mobile telephony protocols, High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packet Access (HSUPA), that extends and improves the performance of existing 3G mobile telecommunication networks utilizing the WCDMA protocols.

HSPA evolution first introduced downlink counterpart called HSDPA in Release 5.

Uplink evolution followed later in Release 6 by the name of HSUPA.

HSPA was originally designed for non-real time traffic with high transmission rate requirements.

HSPA - Introduction

FEATURES-HSPA improves the end-user experience by:

• increasing peak data rates to 14 Mbit/s in the downlink and 5.8 Mbit/s in the uplink

• reducing latency

• providing up to five times more system capacity in the downlink and up to twice as much system capacity in the uplink, reducing the production cost per bit

• link adaptation in downlink

Shared-channel transmission, which results in efficient use of available code and power resources in WCDMA.

A shorter Transmission Time Interval (TTI) , which reduces round-trip time and improves the tracking of fast channel variations.

Link adaptation, which maximizes channel usage and enables the base station to operate at close to maximum cell power.

Fast scheduling, which provides users with the most suitable channel conditions.

Fast retransmission and soft-combining, which further increase the capacity.

16QAM and 64QAM , which yields higher bit-rates. MIMO, which exploits antenna diversity to provide further

improvements in bit-rates and system capacity.

TECHNOLOGIES USED-

ARCHITECTURE-

HSPA PEAK DATA RATES-

5 codes QPSK

# of codesModulation

5 codes 16-QAM

10 codes 16-QAM

15 codes 16-QAM

15 codes 64-QAM

1.8 Mbps

Maxdata rate

3.6 Mbps

7.2 Mbps

10.1 Mbps

14.4 Mbps

2 x SF4 2 ms10 ms

# of codes TTI

2 x SF2 10 ms

2 x SF2 2 ms

2 x SF2 +2 x SF4 2 ms

1.46 Mbps

Maxdata rate

2.0 Mbps

2.9 Mbps

5.76 Mbps

Downlink Theoretical up to 14.4 Mbps Initial capability 1.8 – 3.6 Mbps

Uplink Theoretical up to 5.76 Mbps Initial capability 1.46 Mbps

HSDPA In WCDMA 3GPP Release 5, HSDPA adds a new transport

channel to WCDMA– the High Speed Downlink Shared Channel (HS-DSCH) – which provides enhanced support for high-performance packet data applications in the downlink.

The improved downlink provides up to 14 Mbit/s with significantly reduced latency. Current devices support 7.2 Mbps throughput.

In order to support HSDPA features with minimal impact on the existing radio interface protocol architecture, a new MAC sub-layer, MAC-hs, has been introduced. It enables a functional split to be retained between layers and nodes from WCDMA 3GPP Releases 99 and 4.

HSDPA scheme introduced three new channel types- User data is sent on High Speed Downlink Shared

Channel (HS-DSCH) . Control information is sent on High Speed Common

Control Channel (HS-SCCH) . HS-SCCH is sent two slot before HS-DSCH ,to inform

the scheduled UE of the incoming transmission on HS-DSCH.

High Speed Dedicated Physical Control Channel(HS-DPCCH) carries Channel Quality Indicators (CQIs).

HSDPA CHANNELS

Key Features-

Shared Channel and Multi-Code Transmission Higher-order modulation Short Transmission Time Interval (TTI) Fast link adaptation Fast scheduling Fast Hybrid Automatic Repeat reQuest (ARQ)

Fig: HS-DSCH code and time structures

The network can employ data schedulers that give higher priority to real-time applications.

Employs shorter frame length, thus it can react faster to problems in the radio channel.

Provides shorter delays, which enables new applications, such as interactive networked games.

It is best for applications with highly variable bandwidth requirements.

DISADVANTAGES- Not suitable for applications with low band-width

requirements, such as voice.

ADVANTAGES OF HSDPA-

HSDPA Capability-

The second phase of HSDPA is specified in the 3GPP release7.  

Provides smooth inter-networking between HSPA and LTE, thereby facilitating the operation of both technologies.

Higher-order modulation can be supported in both uplink (16QAM) and downlink (64QAM).

16QAM modulation enables peak data rates of 12 Mbit/s in the uplink, while 64QAM modulation enables peak data rates of 21 Mbit/s in the downlink.

It introduces antenna array technologies such as beamforming and Multiple-input multiple-output communications (MIMO).

HSPA+ (Second Phase of HSDPA)

HSPA/HSPA+(One Tunnel Architecture)

Part of 3GPP Release 8.

Allows a user to connect to two cells at once, thereby theoretically doubling the connection speeds for the user.

Can support up to 28 Mbit/s and 42 Mbit/s with a single 5 MHz carrier in Rel7 (MIMO with 16QAM) and Rel8 (64-QAM + MIMO).

While in Release 8 DC-HSPDA can only operate on adjacent carriers, Release 9 also allows that the paired cells can operate on two different frequency bands.

DUAL CELL HSDPA

THANK YOU!