01 rn31631en40gla0 ranpar1 rrm overview v1.2 ru40.pptx

1 Nokia Siemens Networks RN31631EN40GLA0

RANPAR 1

RN 3163-40A

Nokia Siemens Networks


Course Objectives Explain how NSN RRM is working, what is

measured, when & where Describe the purpose of each RRM functional

entities Identify the relations between different RRM

functional entities Describe the parameter database structure Describe the main RRM parameters

R 255 G 211 B 8

R 255 G 175 B 0

R 127 G 16 B 162

R 163 G 166 B 173

R 137 G 146 B 155

R 175 G 0 B 51

R 52 G 195 B 51

R 0 G 0 B 0

R 255 G 255 B 255

Primary colors: Supporting colors:

146 B 155


Course Content

Radio Resource Management Overview Parameter Configuration Common Channels & Power Control Load Control Admission Control Packet Scheduling Handover Control Resource Manager HSDPA basics & RRM HSUPA basics & RRM HSPA+ features (Overview)


Radio Resource Management (RRM) Overview: 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 RRM functional entity


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 in accordance with user requests

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

RRM

Link Quality

Cell Coverage Cell Capacity


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 call

admissions, 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 actions when the different cell load thresholds are exceeded in order to maintain cell stability (i.e. load control)

Overload

Load Target Overload Margin

Pow

er

Time

Estimated capacity for NRT traffic Measured load caused by non-controllable load (RT)

RT services must have higher quality assurance than NRT


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) 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


Power Control PC WCDMA systems are interference limited; therefore, it is beneficial to reduce

transmission power as far as possible (without violating the required quality). 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 Control Load Control

RNC BTS MS

Power Control Handover Control Admission Control

Load Control Packet Scheduler


Load Control functions 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

Overload threshold x

Load Target threshold y

Pow

er

Time

Estimated capacity for NRT traffic.

Measured load caused by non-controllable load (RT)

Preventative Load Control

Overload Control


Load Control LC

LC performs the function of load control in association with Admission Control AC & Packet Scheduling 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

PS NRT load

Load change info

Load status

Load differentiation: Total load =

Controllable load + Semi-controllable load + Non-controllable load


Admission Control AC Checks that admitting a new user will not sacrifice planned

coverage or quality of existing connections Determines whether RABs or RRC connections can be

admitted Handles RT RABs by estimating the increase in non-controllable load In the decision UL interference & DL power measurements by BTS

are used Since RAS06 the UL throughput is considered for AC, too UL & DL admission conditions must both be fulfilled to admit a new

call or modified existing call

Provides RLC parameters to PS for NRT users, e.g. Bearer class Transport Formats

AC sets quality and power parameters for the radio link, e.g.: UL/DL BLER, Eb/No targets, SIR target Initial DL transmission power

AC takes place in the RNC

Admission Decision

Grant

Reject


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 HSDPA & HSUPA resources are scheduled by the Node B

power

time

non-controllable load controllable load

Total Load

Target threshold

Overload threshold Packet Scheduler in RNC schedules

radio resources for both UL & DL R99 NRT RABs

Scheduling period defined by RNP parameters

PS relies on up-to-date information from AC & LC

Capacity allocated on a needs basis using best effort approach

Packet Scheduler PS


Handover Control HC

Intra-Frequency Handovers Softer/Soft Handover

UE simultaneously connected to multiple cells from same/different Node Bs Mobile Evaluated Handover MEHO

Hard Handover when Inter-RNC SHO is not possible (Iur not supported or Iur congestion) in case of HSDPA

Inter-Frequency Handover can be Intra-BS, Intra-RNC or Inter-RNC Network Evaluated Handover NEHO

Inter-RAT Handover Handovers between WCDMA and GSM, LTE or WLAN Network Evaluated Handover NEHO

WCDMA F1 WCDMA F1 WCDMA F1

WCDMA F2 WCDMA F2

WCDMA F1

HC is responsible for: Managing the mobility aspects of an RRC connection as UE moves around network Maintaining connection quality by ensuring UE is always served by the best cell saving capacity

GSM/LTE GSM/LTE

WCDMA


Resource Manager RM

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 Channelization Code UL Scrambling Code

Cares about 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 from RAS06 on

Code Type Uplink Downlink

Scrambling codes

Channelization codes

User separation Cell separation

Data & control channels from same UE Users within one cell


HSDPA - general principle

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

Hard Handover only

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: Fast HARQ retransmissions Fast Adaptive Modulation & Coding Fast Packet data scheduling (short TTI)

UE1

0 2 0 4 0 6 0 8 0 1 00 1 20 1 40 1 60- 202468

1 01 21 41 6

Time [number of TTIs]

QPS K1 /4

QPS K2 /4

QPS K3 /4

16QAM2/4

16QAM3/4

Instan

tane

ous E

sNo [d

B]


HSUPA / Comparing HSUPA to R99 and HSDPA

HSUPA is 3GPP Rel6 Enhanced FDD Uplink main characteristics:

Peak Rates up to 5.76 Mbps with QPSK Up to 11.5Mbps with 16QAM (RU30) Fast WBTS Packet Scheduling Fast L1 HARQ algorithms Fast Link Adaptation 2ms or 10ms TTI periods Soft Handover SF down to SF = 2

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


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 Continuous Packet Connectivity CS Voice over HSPA

DL Peak Rates up to: 21/28/42 Mbps UL Peak Rates up to: 5.8 Mbps

RU20

General Improvements: Fast Dormancy Multi-Band Load Balancing MBLB High Speed Cell_FACH (DL)

HSUPA Improvements: HSUPA 11Mbps (16QAM) Frequency Domain Equalizer HSUPA Interference Cancellation Receiver

DL Peak Rates up to: 42 Mbps UL Peak Rates up to: 11 Mbps

RU30


HSPA+ Improvements HSDPA Improvements:

DC-HSDPA + 64QAM + MIMO (84Mbps) Dual Band HSDPA (42 Mbps)

General Improvements: High Speed Cell_FACH (DL+UL) Smart LTE Layering Application Aware RAN


RU40

HSDPA Improvements: MC-HSDPA (168 Mbps) HSDPA Multiflow

General Improvements: Measurement based LTE Layering Conversational QoS for VoIP RAN Optimized Content Delivery

HSUPA Improvements: DC-HSUPA (23 Mbps)


RU50 under planning

01 rn31631en40gla0 ranpar1 rrm overview v1.2 ru40.pptx

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