dc-hspa and carrier aggregation

Cellular Communication

Systems

***The Inside Story

Contents

Main Issues (Resources,

Capacity, Access, etc.)

Concepts Of Wireless

Communication

2G, 3G, LTE Topologies

DC-HSPA

Addresses how the overall resource (time, frequency and

space) of the system is shared by the users in the same cell

(intra-cell)

Addresses the interference caused by simultaneous signal

transmissions in different cells (inter-cell)

Two main issues in cellular communication: multiple access and interference management



Multiple Access

Interference

Management

Time Division Duplex:

separates the transmissions in time

Frequency Division Duplex:

separates the transmissions in frequency

In addition, there is also an issue of how the resource is allocated between the uplink (the reverse link) and the downlink (the forward link). DUPLEXING



TDD

FDD

A cellular network provides coverage of the entire area by dividing it into cells.



Contents




Communication


DC-HSPA

Intelligent allocation and reuse of channels throughout a coverage region.

A set of radio channels for each base station, cell.

Adjacent cells: completely different channels

Same group of channels may be used to cover different cells that are separated from one another to keep interference levels within tolerable limits

Frequency Reuse


Communication

When a mobile moves into a different cell while a conversation is in progress, the call is transferred to a new channel belonging to the new base station.

Points To Consider:A. Hard handover VS. Soft handovers

Handovers


Communication

A major limiting Factor

Sources : mobile in the same cell, a call in progress in a neighboring cell, or other base stations operating in the same frequency band.

A. Co-channel Interference

B. Adjacent Channel Interference

Interference and System Capacity


Communication

Demand goes up

The number of channels insufficient.

Design techniques to provide more.

Cell splitting and sectoring.

Improving Coverage and Capacity in Cellular Systems


Communication

Cell splitting is the process of subdividing a congested cell into smaller cells

Cell Splitting


Communication

Dividing a cell into three (or six) equal-space sectors using directional antennas.

The channels used in a particular cell are broken down into sectored groups and are used only within a particular sector

Increasing the frequency reuse.

Cell Sectoring


Communication

Hard-to-reach areas: within buildings, or in valleys or tunnels.

Radio re-transmitters, known as repeaters, are often used to provide such range extension capabilities.

Repeaters for Range Extension


Communication

MULTIPLE ACCESS TECHNIQUES

Allow many mobile users to share simultaneously a finite amount of radio spectrum.

Mobiles are Mobile ---- No easy way ---- More penetration ----More valuable is the spectrum ---- Role Of Multiple Access

Points To Consider:A. Duplexing

B. High capacity is required.

C. NO severe degradation in the performance.

Multiple Access

Three major techniques:

A. Frequency division multiple access (FDMA)

B. Time division multiple access (TDMA)

C. Code division multiple access (CDMA)

Others:

A. Orthogonal Frequency Division Multiple Access (OFDM)

Techniques

Multiple Access

Contents




Communication


DC-HSPA

The GSM network can be divided into following broad parts:

** The Mobile Station (MS)** The Base Station Subsystem (BSS)** The Network Switching Subsystem (NSS)

2G -GSM

First Introduction Of DATA….

Same network + some changes

Mobile Station (MS)New Mobile Station is required to access GPRS services. These new terminals will be backward compatible with GSM for voice calls.

GPRS Support Nodes (GSNs)Installation of new core network elements : the serving GPRS support node (SGSN) and gateway GPRS support node (GGSN).

The BTS, BSC, HLR, VLR needed only software upgrades.

GPRS

SGSN = Serving GPRS Support Node, GGSN = Gateway GPRS Support Node, and GR = GPRS Register.

From a GSM/GPRS network, the following network elements can be reused:

(HLR) --- (VLR) --- (EIR) --- (MSC) --- (AUC) --- (SGSN) --- (GGSN)

From a GSM/GPRS communication radio network, the following elements cannot be reused:

Base station controller (BSC)Base transceiver station (BTS)

**Remain, Dual network operation, 2G/3G co-exist

Migrating from GSM/GPRS to UMTS

3G -UMTS

The UMTS network introduces new network elements that function as specified by 3GPP:

NODE B : WCDMA--- Frequency use (the whole network can use a single frequency pair)/ Power requirements.

Radio Network Controller (RNC) : mainly control the NODE Bsand their power levels.

Migrating from GSM/GPRS to UMTS … Cont’d

3G -UMTS

The Quest For More:

More Spectrum

More Capacity

More Small Cells

More Speed (D&U)

More Business Solutions

More Consistency

And Less COSTS

More Users

More Market

Penetration

And Less COSTS

Peak download rates up 300 Mbit/s and upload rates up to 75 Mbit/s

MIMO (with 2×2 / 4×4 antennas using up to 20 MHz of spectrum).

The LTE standard supports only packet switching with its all-IP network --- Global Roaming

Improves call set-up time.

Higher data-carrying capacity and a higher spectral efficiency.

Lowers the cost-per-bit.

Increase the efficiency of entire network.

Operations easier and less expensive to manage.

WHY

LTE

It uses OFDMA radio-access for the downlink and SC-FDMA on the uplink

EUTRAN consists only of ENODEBs on the network side.

The ENODEB performs tasks similar to those performed by the NODEBs and RNC (radio network controller) together in UTRAN.

The aim of this simplification is to reduce the latency of all radio interface operations.

LTE’s Radio Access Network (EUTRAN) : Evolved UMTS Terrestrial Radio Access

LTE

Evolved Packet Core Network

LTE

* Flat architecture, avoid protocol conversion.

* Separate the user data and the signaling

Very basic architecture of the EPS

LTE EPS

LTE

Contents




Communication


DC-HSPA

3 Source: www.gsacom.com , Feb 2014

547HSPA NETWORKS IN 205 COUNTRIES

363HSPA+ NETWORKS IN 157 COUNTRIES

160DUAL-CARRIER NETWORKS IN 83 COUNTRIES

HSPA+: Building upon the solid global foundation

9

HSPA+ Dual-carrier is main-stream Supporting 42 Mbps downlink peak data rate

Deployment of 42 Mbps DC-HSPA+ technology continues as the major trend in 2014 – GSA, Mar 2014

160 NETWORKS

83 COUNTRIES

Countries launched/committed to Dual-carrier

Source: www.gsacom.com , Feb 2014

HSPA & WCDMA : A True Success

Enhancements and new features : HSPA+, 3GPP rel. 8 to 10

Data rates .. Spectral efficiency .. Latency in the system

DUAL CARRIER-HSDPA

How It Works

How It Works

HSPA Additional Channels:

WHY: Provide the additional data capacity, the control required.

In addition to the existing 3G UMTS channels.

DUAL CARRIER-HSDPA

How It Works

High Speed Downlink Shared Channel, HS-DSCH** Data transport channel.

High Speed Signaling Control Channel, HS-SCCH** Control Channel: Carries elements of info.** Signal the scheduling to the users.

High Speed Dedicated Physical Control Channel, HS-DPCCH

** Feedback to the scheduler.** Located in the UL.

DUAL CARRIER-HSDPA

How It Works

Carrier Aggregation ** 2 Engines in one car, driving with doubled rate

in the DL.

** DC-HSPA: Two adjacent DL carriers (5 MHz) + one UL .. Peak rates D: 42 Mbps

** Scheduling and coordination:

-NODEB’s Scheduler.

-One HS-SCCH for each 5 MHz carrier.

-Decisions based on CQI (Channel quality info.) feedback.

SO How It Works

10

Dual-carrier – Delivering high data rates in real networks

>5Mbps >50%

Source: Signals Research Group Signals Ahead, September 2011, “The Mother of all Network Benchmark Tests”

0 – 0.25Mbps 8.6%

0.25 – 0.5Mbps 4.8%

0.5 – 1Mbps 8.1%

1 – 1.5Mbps 6.5%

1.5 – 2Mbps 4.6%

2 – 2.5Mbps 3.8%

2.5 – 5Mbps 11.4% 5 – 7.5Mbps

9.9%

7.5 – 10Mbps 8.8%

10 – 12.5Mbps 8.7%

12.5 – 15Mbps 10.6%

15 – 20Mbps 14.1%

>1Mbps ~80%

USER DATA RATE OF THE TIME

Based on comprehensive benchmarking tests conducted across two operators in greater Dallas area (Texas), covering more than 23 miles of

driving, downloading nearly 7GB of data

USER DATA RATE OF THE TIME

ThanksFor

Listening

BIBLIOGRAHY:

• ITU (International Telecommunication Union)

• Ericsson, QUALCOMM, and Alcatel-Lucent White Papers.

• The 3rd Generation Partnership Project (3GPP) Releases.

• Rohde-Schwarz• Radio-Electronics.com