ranpar rrm overview

8/13/2019 Ranpar Rrm Overview

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1 Nokia Siemens Networks Presentation / AA / 01_2010

I insert classification level

Course Content

Radio Resource Management Overview

Parameter Configuration

Common Channels & Power Control

Load Control

Admission Control

Packet Scheduling

Handover Control

Resource ManagerHSDPA RRM & parameters

HSUPA RRM & parameters

HSPA+ RRM (Rel. 7/8)


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Soc Classification level

Module Objectives

At the end of the module you will be able to:

Describe the purpose of RRM

List the RRM functional entities

Describe the purpose of each of the RRM functional entities

Identify the location of RRM entities


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Introduction

Load Control (LC)

Admission Control (AC)

Packet Scheduler (PS) incl. HSPA

Power Control (PC)

Handover Control (HC)

Resource Manager (RM)

RRM of HSDPA

RRM of HSUPA

RRM of HSPA+ (Rel. 7/8)


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Radio Resource Management

Target for RRM is to ensure the RAN offers:

The planned coverage for each targeted service

High capacity i.e. low blocking (new calls, handovers)

The required Quality of Service (QoS)

Optimize the use of available capacity (priorities)

By continuously monitoring/adjusting how the available resources are used inaccordance with user requests

Radio Resource Management (RRM) is responsible for optimalutilisation of the air interface resources

RRM

Link Quality

Cell CoverageCell Capacity


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RRM Tasks

RRM must be able to:

Predict the impact on interference (power) of

the admitting a new user for UL & DL

Perform appropriate actions (e.g. new calladmissions, bitrate increase/decrease etc.) in

accordance with prevailing load conditions

Provide different quality of service for real

time (RT) and non-real time (NRT) users

Take appropriate corrective action when the

different cell load thresholds are exceeded in

order to maintain cell stability (i.e. loadcontrol)

Overload

Load Target

Overload Margin

Power

Time

Estimated capacityfor NRT traffic

Measured load causedby non-controllable load(RT)

RT services must have higher quality assurance than NRT


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RRM is made up of a number of closely interdependent functions (i.e.algorithms)

These functions can be divided into;

Cell Based Load control (LC)

Admission control (AC)

Packet scheduling (PS) High Speed Downlink Packet Access

Resource manager (RM)

Connection Based

Handover control (HC)

Power control (PC)

RRM Functional Split

PC

HC

Connection based functions

LC

AC

Cell based functions

PS

RM





Introduction

Load Control (LC)



Power Control (PC)



RRM of HSPA




Load control States

The load control function within RRM can be divided:

Preventative load control (e.g. congestion)

Overload control (e.g. dropping of calls in worst case)

Preventative actions are performed before the cell is overloaded (threshold y) Overload actions are performed after cell is overloaded (threshold x)

RNP parameters define the thresholds for the RRM functionalities

The thresholds define a stable functionality within a cell & with surrounding cells

Overloadthreshold x

Load Targetthreshold y

Power

Time

Estimated capacity forNRT traffic.

Measured load caused

by non-controllable load(RT)

Preventative Load Control

Overload Control




Load Control

LC performs the function of load control in association with AC & PS

Updates load status using measurements & estimations provided by AC & PS

Continuously feeds cell load information to PS & AC:

Interference levels

BTS power levels

Non-controllable load

LC

AC

PSNRT load

Load change info

Load status

Load differentiation:

Total load =

Controllable load +

Semi-controllable load +

Non-controllable load





Introduction

Load Control (LC)



Power Control (PC)



RRM of HSPA




Admission Control

Responsible for maximising capacity (throughput) whilst providing the required quality of

service for RT traffic.

Checks that admitting a new user will not sacrifice planned coverage or quality of existing

connections

Determines whether RABs can be admitted to the RAN

Handles RT RABs alone by estimating the increase in non-controllable load

With PS decides whether to allocate resources to NRT RABs

In the decision UL interference & DL power measurements by BTS are used

Since RAS06 also the UL throughput is considered for AC

Provides RLC parameters to PS for NRT users, for example

Bearer class

Transport Formats

AC sets quality and power parameters for the radio link, for example

UL/DL BLER, Eb/No targets, SIR target

Initial DL transmission power




Admission Control (RAS05.1 picture)

In UL the received total wideband interference power (RTWP) measured indicates thetraffic load of the radio resources.

For DL the power change caused by new RT service is obtained from the maximum

allowed DL transmission power for the service.

In the admission decision procedure new call (or modified existing call) is admitted if

both UL and DL admission decisions are passed

Prx_target

Prx_target_BS

UL interference power

Load

Planned load area

Marginal load area

PrxTotal

RNP decisionthresholds

RNP: Radio Network Planning




Admission Control, UL

Noise Rise

Own Cell Load Factor(throughput)

i-factor

PrxOffset

Minimumthroughput

DCH

PrxLoadMarginDCH

Maximum

throughputDCH

PrxLoadMarginMaxDCH

PrxTarget

Throughput thresholds are calculated from new, configurable Prx thresholds (since RAS 06)


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Introduction

Load Control (LC)



Power Control (PC)



RRM of HSPA


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PS allocation times need to be fast to accommodate changing conditions &

accurate (up-to-date load info)

Capacity requests sent via traffic volume measurement reports (governed by

RNP parameters)

PS comprises two parts: UE specific & Cell specific

power

time

non-controllable load

controllable load

Total Load

Target threshold

Overload threshold

Responsible for scheduling radio

resources for both UL and DL R99 NRT

RABs

Scheduling period defined by RNP

parameters

PS relies on up-to-date information from

AC and LC

Capacity allocated on a needs basisusing best effort approach

Packet Scheduler in RNC


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Introduction

Load Control (LC)



Power Control (PC)



RRM of HSPA


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Power Control (PC)

Since WCDMA system is interference limited it is beneficial to reduce

transmission power as far as possible.

Thus, the target of PC is to achieve the min. SIR that is required to offer

sufficient quality of the connection. PC works on a per-connection basis.

Power Control

Power ControlLoad Control

RNCBSMS

Power ControlHandover Control

Admission ControlLoad Control

Packet Scheduler


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Introduction

Load Control (LC)



Power Control (PC)



RRM of HSPA


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HC is responsible for

Managing the mobility aspects of an RRC connection as UE move around network

Maintaining high capacity by ensuring UE is always served by best cell

Intra-layer

Inter-layer

Intra-System

Soft(er) Handover

Hard Handover

Inter-frequency

Intra-frequency

Intra-frequency

Inter-System(Inter-RAT)

Hard HandoverInter-frequency

WCDMA to GSMWCDMA to GPRSGSM to WCDMA

GPRS to WCDMA

WCDMA to WCDMA

Intra-layer

Inter-layer

Intra-layer

Inter-layer

Intra-layer

Inter-layer

RequiresCompressed

Mode or DualReceiver UE


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Introduction

Load Control (LC)



Power Control (PC)



RRM of HSPA


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Responsible for managing the logical radio resources of the RNC in co-operation with

AC and PS

On request for resources, from either AC(RT) or PS(NRT), RM allocates;

DL spreading code

UL scrambling code

Also looks after code tree management (to maintain orthogonality); Initial code selection codes concentrated to same branch

Code de-fragmentation dynamic reallocation of codes as users enter/leave system

DL spreading code allocation for HSDPA users can be dynamic in RAS06

Code Type Uplink Downlink

Scrambling codes

Spreading codes

User separation Cell separation

Data & control channels from same UE Users within one cell


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Introduction

Load Control (LC)



Power Control (PC)



RRM of HSPA (HSDPA, HSUPA & HSPA+)


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HSDPA - general principle

Fast scheduling is done directly in Node-B based on feedback information from UEand knowledge of current traffic state.

UE2

Channel quality(CQI, Ack/Nack, TPC)

Channel quality(CQI, Ack/Nack, TPC)

Data

Data

Users may be time and/or code multiplexed

New WBTS functions

HARQ retransmissions

Modulation/coding selection (16QAM)

Packet data scheduling (short TTI)

New WBTS functions

HARQ retransmissions

Modulation/coding selection (16QAM)

Packet data scheduling (short TTI)

UE1

0 20 40 60 80 100 120 140 160-2

0

2468

10121416

Time [number of TTIs]

QPSK1/4

QPSK2/4

QPSK3/4

16QAM2/4

16QAM3/4

InstantaneousEsNo[dB]


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Comparing HSUPA to R99 and HSDPA

HSUPA is 3GPP Rel6 Enhanced FDD Uplink

main characteristics:

Fast WBTS Packet Scheduling

Fast L1 HARQ algorithms

Fast Link Adaptation

2ms or 10ms TTI periods

Soft Handover SF down to SF = 2

Peak Rates up to 5.76 Mbps

Feature

Rel99

DCH

Rel5

HSDPA

Rel6

HSUPA

Var. spreading factor Y N Y

Fast power control Y N Y

Adaptive modulation N Y N

WBTS based scheduling N Y Y

Fast L1 HARQ N Y Y

Soft Handover Y N Y

TTI length [ms] 80,40,20,10 2 10,2

E-DCH


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25 N ki Si N t k P t ti / AA / 01 2010


HSPA+ Improvements

Improving the DL peak rates, cell throughput & spectrum efficiency:

64QAM: Enhanced HSDPA Modulation

MIMO: Intelligent Multi-Antenna Systems

DC-HSDPA: Dual-Carrier/Cell Transmission

Improving the cell throughput & spectrum efficiency:

DL Flexible RLC

CPC: Continuous Packet Connectivity CS Voice over HSPA

Peak Rates up to:

21 / 28 / 42 Mbps

ranpar rrm overview

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