Advanced Resource Management Solutions for Future All IP ... · Radio Access Network (IP-RAN) UMTS-based Core Network Medium term scenario assumptions: - Backhaul already migrated

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Joint workshop COST2100-AROMA-NEWCOM, Brussels, December 13th, 2006

AROMA

AROMA

AROMA

Jordi Pérez-Romero

Universitat Politècnica de Catalunya (UPC)

Advanced Resource Management Solutions for Future All IP Heterogeneous Mobile Radio

Environments

Advanced Resource Management Solutions for Future All IP Heterogeneous Mobile Radio

Environments

2Joint workshop COST2100-AROMA-NEWCOM, Brussels, December 13th, 2006

AROMA

AROMA

- AROMA Consortium- AROMA Objectives- AROMA Reference Architectures- AROMA Scenarios- Common Radio Resource Management

- Architectures- RAT selection- Common Congestion Control

- Coordinated Radio and Transport Resource Management- Architectures- Functionalities- Coordinated Congestion Control

- Conclusions

OutlineOutline

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Academia• Universitat Politècnica de Catalunya (UPC) – Spain• King’s College London (KCL) – U.K.• Instituto Tecnico Superior- Technical University of

Lisboa (IST-TUL) - Portugal

Mobile Operators• Portugal Telecom Inovação (PTIN) – Portugal • Telecom Italia (TI)- Italy• Telefónica I+D (TID)- Spain• Telia–Sonera (TEL) - Sweden

Mobile Operator driven STREP project

Project AROMA ConsortiumProject AROMA Consortium


AROMA

AROMA

The AROMA project aims to devise and assess a set of specific strategies and algorithms for both the access and the core network parts that can guarantee the end-to-end QoS in the context of an all-IP heterogeneous radio access network

Project AROMA Main ObjectivesProject AROMA Main Objectives

AROMA addresses in an integral way the end-to-end QoS provision in Mobile networks. In particular, AROMA focuses in both a Heterogeneous Access Networks and an IP-based core and access transport network.

AROMA contributes to the development of an efficient wireless accessassuming IP based services.

The results coming from the AROMA project will provide a manufacturer-independent analysis of the end-to-end QoS strategies, which allow the mobile operators to evaluate and compare solutions coming from the market with an available reference of the system performance.

AROMA is the natural continuation of two legacy project ARROWS and EVEREST

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Techniques:

- RRM (Radio Resource Management)- CRRM (Common Radio Resource Management)- CARM (Common Access Resource Management)- Automatic Tuning

Framework:

- Current RATs (UMTS, GERAN, WLAN…)- Current spectrum allocation- Current regulatory framework

Scope and ApproachesScope and Approaches


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Space Resolution

Use

rC

ell

Reg

iona

l

Time Resolutionµs ms s mn 10s mn ½ day day month

Short term Middle term Long term

Short

space

Middle

space

Large

space

Automatic tuning

RRMCRRMCARM

Scope and ApproachesScope and Approaches

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AROMA reference architecture – Medium term scenario

RNC SGSNBSCMSC ServerGANC

PSTN/ISDN

CS-MGW GGSN

IMS ServicesExternal PDN

WLAN AP

Node-B BTS

IP-based transport backhaul IP-based transport core network

3GPP R6 network architectureMulti-mode terminals

Rad

io N

etw

ork

Laye

r (R

NL)

Tran

spor

t Net

wor

k La

yer (

TNL)

Radio Access Network (IP-RAN) UMTS-based Core Network

Medium term scenario assumptions:- Backhaul already migrated to IP transport- Iub interface fully supported over IP transport


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AROMA reference architecture – Medium term key drivers

RNC SGSNBSCMSC ServerGANC

PSTN/ISDN

CS-MGW GGSN


WLAN APNode-B BTS

IP backhaul IP transport network

radi

o

IP transportIP transport IP transport

Access network e2e QoS

Key Drivers CRRMRadio and IP transport coordination

(GERAN and WLAN may share backhaul resources or not)

RRM RRM RRM

CRRM

RRM

Over-provisioning in the backhaul may not be economically feasible

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AROMA reference architecture – Long term scenario

aGW

PSTN/ISDN

MGW


eNB


MMEUPE

RRCBorder GW

Inter ASanchor

Aligned to 3GPP SAE/LTE

Long term scenario assumptions:- Aligned to TR 25.912- Iub interface no longer needed- High capillarity needs efficient resource management


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AROMA reference architecture – Long term key drivers

PSTN/ISDN

MGW


eNB


RRCBorder GW

radio

IP nativeIP transport/native?

Access network e2e QoS

RRM

Key DriversMulti-cell RRMIETF IP solutions for mobility and QoSRadio and IP transport coordination

aGW

MMEUPE

Inter ASanchor

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• Six selected target scenarios• Three theoretical: Hot Spot within urban area, Hot spot along main road

and Urban residential area

• Three realistic: urban/suburban, dense urban area & multifloor

• Scenario description items• Network architecture and entities • Services mix and traffic load• Environment; suburban, urban and indoor• Radio access technologies and capabilities• Characterisation of the Transport Network

AROMA ScenariosAROMA Scenarios

GSM / GPRSUMTS UMTS UMTS

WLAN


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VoiceVideotelephonyVideo streamingWeb browsingEmailMMSFTP

Service UL kbytes/user/BH DL kbytes/user/BH Voice 75 75 Video Streaming 5 113 Video Telephony 53 53 Web Browsing 60 312 Email 88 328

The scenario vision encompasses the heterogeneous network supporting users with multimode mobile terminals with a target year around 2010.

AROMA ScenariosAROMA Scenarios

60%

4%

10%

10%

6%

7%3%

50%

4%10%

12%

11%

3%

10%Consumer users Business users

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RRU (Radio Resource Unit): Set of basic physical transmission parameters necessary to support a signal waveform transporting end user information corresponding to a reference service.

RRU in FDMA: a certain bandwidth within a given carrier frequency RRU in TDMA: a pair of a carrier frequency and a time slotRRU in CDMA: a carrier frequency, a code sequence and a power level

RADIONETWORKPLANNING

RADIONETWORK

DEPLOYMENT

RADIONETWORK

OPERATION

RRU provision along timeand space

RRU allocation

RRM / CRRM

Radio Resource Management (RRM)Radio Resource Management (RRM)


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AROMA – RRM/CRRM ObjectivesAROMA – RRM/CRRM Objectives

• To develop advanced RRM strategies and algorithms in the context of 3G and Beyond systems, ensuring the QoS requirements of the proposed services, providing the planned coverage and increasing capacity. In particular, algorithms will target:

Individual RRM for different RANs

CRRM for heterogeneous RANs

• To assess and evaluate the proposed algorithms in a number of relevant scenarios, technological functionalities, network layout structures, services mix, etc. with the idea to cover medium- and long-term foreseen evolutions

f

GERAN ttt

c

UTRAN WLAN

RRM-GERAN RRM-UTRAN RRM-WLAN

f

GERAN ttt

c

UTRAN WLAN

RRM-GERAN RRM-UTRAN RRM-WLAN

f

GERAN ttt

c

UTRAN WLAN

CRRM

f

GERAN ttt

c

UTRAN WLAN

CRRM

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AMOUNT OFCOMMON

RADIORESOURCES

GERAN RADIO RESOURCESUTRAN RADIO RESOURCESWLAN RADIO RESOURCES

Common Radio Resource ManagementCommon Radio Resource Management


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CRRM – Functional modelCRRM – Functional modelThe functional model assumed in 3GPP for CRRM operation:

The interactions between RRM and CRRM entities involve two types of functions:a) Information reporting function

- Dynamic (e.g. cell load, transmitted carrier power, interference measurements, etc.)- Static (e.g. cell relations in HCS layers, cell capabilities and configuration)

b) RRM decision support functionCRRM simply advises the RRM entity (i.e. RRM remains as the master of the

decisions) or CRRM is the master, so that its decisions are binding for the RRM entity.

CRRM entity

CRRM entity

RRM entity

RRM entity

RRM entity

RRM entity

- Information reporting

- Information reporting - RRM decision support

- Information reporting - RRM decision support

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RRM functionalities in a single-RAT context:• Admission control• Congestion control• Horizontal (intra-system) handover• Packet scheduling• Power control

When these functionalities are coordinated between different RATs in a heterogeneous scenario, they can be denoted as “common”

In an heterogeneous scenario a new functionality arises: RAT selection (bothinitial RAT selection and Vertical Handover)

CRRM – Functionalities & splitCRRM – Functionalities & split

There exists a range of possibilities for the set of functionalities that the CRRM entity may undertake

The CRRM entity may be implemented either into existing nodes (i.e. RNC, BSC and APC) or in a separate node


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CRRM - TopologiesCRRM - Topologies

RNC

RRM entity

UTRAN GERAN

RNC

RRM entity

BSC

RRM entity

BSC

RRM entity

CRRM server CRRM entity

Core Network

RNC

CRRM entity

RRM entity

BSC

CRRM entity

RRM entity

RNC

CRRM entity

RRM entity

RNC

RRM entity

BSC

RRM entity

UTRAN GERAN

Core Network

CRRM server

Integrated CRRM

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CRRM - WLANCRRM - WLANThe interworking with WLAN is devised from a different perspective because WLANs are being mainly deployed by independent operators, not belonging to 3GPP, and consequently they do not follow the same networking architectures of 3GPP systems like UMTS or GSM/EDGE.

RNC

UTRANGERAN

Core Network

BSC

SGSN

APC

WLAN

GGSN

Data Network (Internet)

data flow signalling

HSS

Gi

IuIu/Gb Iu

A tight coupling approach allows consideringthe WLAN as an additional access network

like GERAN or UTRAN.

In order to support RRM and CRRM the functionalities of the Access Point Controller (APC) should be equivalent to the RNC or the BSC for the UTRAN and GERAN.


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RAT selectionRAT selectionSome possible guiding principles for RAT selection are:

Service-based RAT selection. A service-based RAT selection policy is based on a direct mapping between services and a prioritised list of preferred RATs.

Load-balancing RAT selection. This policy will distribute the load among all resources as evenly as possible.

Interference-based RAT selection. This principle intends to anticipate the effects that the allocation of a certain connection request to a certain cell and RAT will cause in terms of interference. Then, different criteria could be used for the RAT selection so that the interference tends to be minimised.

TerminalcharacteristicsServices

& QoS

RATsavailable

RATssupported Cell load

conditions

UE interferenceconditions

Userprofile

Operatorpreferences

RAT & CellSelection

Objective: To devise a generic framework that takes the different principles into account together with different conditions (non-homogeneous system conditions along time and space, service dimension, user category dimension, terminal capabilities dimension, etc.)

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Example of RAT selection algorithmExample of RAT selection algorithm

VHO PROCEDURE

LUTRAN>Lth+∆ for Mup consecutive

samples

Y

N

User in UTRAN

Y

N

VHO to GERAN

Do NOTHING

Y

Y

VHO to UTRAN

N

Voice

Y

N

Y

N

Interactive

RAT SELECTION

Start of session

LUTRAN>LthY N

Capacity available in

UTRAN

N

Y Y

N N

N

YY

ACCEPT IN GERAN

ACCEPT IN UTRAN

Service

Voice

Interactive

BLOCK CALL

INITIAL RAT SELECTION

YN


GERAN


GERAN


UTRAN Capacity

available in GERAN


UTRAN

Service

LUTRAN<Lth-∆ for Mdown consecutive

samples

User in UTRAN


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Example of RAT selection algorithmExample of RAT selection algorithmThe algorithm combines:

• Service principle (preference of UTRAN for interactive traffic)• Interference principle (tends to avoid at the possible extent to assign high path

loss users to WCDMA RAT)• Load balancing principle (setting of the path loss threshold Lth as a certain

percentile of the statistical path loss distribution)

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

90 95 100 105 110 115 120 125 130 135 140

L (dB)

CDF

PLth=125 dB(80-th perc)

PLth=120 dB(60-th perc)PLth=115 dB

(40-th perc)

Key single parameter: Lth

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Example of RAT selection algorithmExample of RAT selection algorithm

Throughput gain up to 25%are observed with theproposed algorithm

Optimisation throughsuitable Lth setting

With different dominant principles

Downlink throughputVoice-only scenario Lth=120 dB

1.5

2

2.5

3

3.5

4

4.5

5

400 500 600 700 800 900 1000 1100 1200

Voice UsersD

L Th

roug

hput

(Mb/

s)

CRRM Algorithm

Load Balancing


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0

5

10

15

20

25

30

35

100 75 50 25Mult i-mode T erminal Availability (%)

Thro

ughp

ut D

egra

datio

n (%

)

VU=600;WU=600

VU=400;WU=400

VU=200;WU=200

UL Throughput degradation

• Increases degradation with

decrease of multi-mode availability

• Impact on the interactive users

exhibiting higher delays

Proposed solution: Average Packet Delay improvement with dedicated slots(i.e. some reserved resources for single-mode terminals)

Study provides insight into evolutionary paths (e.g. suitability to subsidizemulti-mode terminals to exploit CRRM gain depending on load levels)

Impact of Multi-Mode TerminalsImpact of Multi-Mode Terminals

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• Radio-Access Congestion Overload– UTRAN: ⇈ interference.– GERAN: ⇈ (data) timeslot reuse.

• Classical approach:– Congestion Detection (CD) ✔

• CD metric definitions for each RAT.• CR triggering mechanisms.

– Congestion Resolution (CR) ✔• CR algorithms:

– Resource Creation scheme: » Attempt VHO from congested BS/RAT to non-congested BS/RAT (VHO-CR).

– Demand Reduction schemes:» Bit-Rate Reduction (BRR-CR)» User Dropping (DROP-CR)

• User prioritization on which to perform algorithms. – Congestion Recovery (CRV)

Common Congestion ControlCommon Congestion Control


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• Congestion Detection (CD):– Metric UTRAN: Load Factor:

– Metric GERAN: Timeslot Reuse Factor (RF)

– Threshold-based triggering mechanism:

0 if 01 if 0

if

d

d d

dd d

d

NN C

RFC N CN

= < ≤= >

1 NUL

total

PI

η = −max

totalDL

PP

η =

4 0.410d

d

CRF N= = =

{ }, thUL DLη η> { }, thUL DLRF RF<


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• Congestion is detected in UTRAN and we try to solve it by performing VHO over GERAN users towards UTRAN.

• Expected negative impact on GERAN due to RF reduction.


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• Given a congestion situation in both RATs, using only VHO will not solve congestion. Idea: reduce load in UTRAN by reducing bit-rate demands so that:

1. Congestion in UTRAN is mitigated.2. GERAN users can be directed to UTRAN by means of VHO.


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RRM RAT n

MC

RPSLC

AC CC

BS

Radio Controller(RNC, BSC, GANC)

Base Station(NodeB, BTS, AP)

SGSN GGSNMobile Terminal

Radio Resources IP Transport Resources IP Transport Resources IP Transport Resources

TRM

R5/R6

CC

PSRC

BS

AC

RRM RAT2

MC

RPSLC

AC CC

BS

RRM RAT1

MC

RPSLC

AC CC

BS

CRRM RS

RRM and TRM QoS functionsRRM and TRM QoS functions

CRRM:- RAT Selection (RS)

RRM and TRM:- Admission Control (AC)- Congestion Control (CC)- Bearer Selection (BS)

RRM:- Mobility Control (MC)- Radio Link Control (LC)- Radio Packet Scheduling (RPS)

TRM:- TNL Route Control (RC)- TNL Packet Scheduling (PS)


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CARM QoS functionsCARM QoS functions

RRM RAT n

RPSLC

RRM RAT 2

RPSLC

Radio Controller(RNC, BSC, GANC)

Base Station(NodeB, BTS, AP) SGSN GGSN

Mobile Terminal

Radio Resources IP Transport Resources IP Transport Resources IP Transport Resources

TRM

PS

RRM RAT 1

RPSLC RCMC

CC

AC

BS

CRRM RS

Coordinated Access Resource Management

(CARM) functions

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BearerSelection

Radio PacketScheduling

Congestion Control

Link Control

RRM functions TRM functions

TNL PacketScheduling

RouteControl

AdmissionControl

MobilityControl

CARM functions

RAT Selection

Proposed CARM QoS functionsProposed CARM QoS functions

• Goals:– Resource optimisation (RNL and TNL)– Business strategies (e.g. business users vs. consumer users)


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Transport Congestion ResolutionMechanisms based on RRM within the RNL:

•Bit rate reduction for non-guarateed PS services•Redistribute traffic via HO and network controlledcell reselection (intra/inter RAT)•Reduce soft HO connections•Flow control for High Speed channels•Increase admission blocking•Drop active sessions

Tranport Network CongestionResolution Mechanisms within the TNL itself:

•Packet Discarding policies (blind/selective)•Path re-calculation (routing control)

How TNL congestioncan be preventedand/orsolved?

Where TNL congestion oroverloadsituations can be detected?

Transport Congestion/Overload DetectionMechanisms in the radio layer

Transport Congestion/Overload DetectionMechanisms in the transport layer

Coordinated Congestion Control approachpure RNLapproach

pure TNL approach

Transport Congestion ResolutionMechanisms based on RRM within the RNL:

•Bit rate reduction for non-guarateed PS services•Redistribute traffic via HO and network controlledcell reselection (intra/inter RAT)•Reduce soft HO connections•Flow control for High Speed channels•Increase admission blocking•Drop active sessions

Tranport Network CongestionResolution Mechanisms within the TNL itself:

•Packet Discarding policies (blind/selective)•Path re-calculation (routing control)

How TNL congestioncan be preventedand/orsolved?

Where TNL congestion oroverloadsituations can be detected?

Transport Congestion/Overload DetectionMechanisms in the radio layer

Transport Congestion/Overload DetectionMechanisms in the transport layer

Coordinated Congestion Control approachpure RNLapproach

pure TNL approach

Cover those situations where: (1) pure-TNL mechanisms do not suffice to alleviate a given congestion situation and consequently the RNL

should be involved in congestion handling, and (2) useful metrics to characterise overload/congestion situations are computed in the TNL itself and notified to the

RNL, instead of letting the RNL layer to detect congestion by itself, so that the reaction of the RNL can be better directed to the location and adjusted to the severity of the overload situation.

Example: Coordinated Congestion ControlExample: Coordinated Congestion Control

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IP Transport Network

RNCn

RNCm

NodeBi

NodeBj

NodeBk

TNL Monitoring

Measurements

Congestion metrics

CoordinatedCongestionResolutionmechanims

li

lj

A bottleneck link in the transportnetwork is considered



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a) Mean LU (%)

50

55

60

65

70

75

80

85

90

95

0.4 0.5 0.6 0.7

Normalised Goodput

DCH64DCH128DCH256

b) Prob (LU>0.95) (%)

0

10

20

30

40

50

60

70

0.4 0.5 0.6 0.7Normalised Goodput

DCH64DCH128DCH256

c) FP PDU Loss Ratio (%)

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5


DCH64DCH128DCH256

Potential Congestion Control Gain

Effect of the DCH bit rate selection in the LU indicator and potential coordinated congestion control gain.


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a) Mean LU (%)

50

5560

6570

75

8085

9095

100


Rep_Range=10dBRep_Range=0dB

b) FP PDU Loss Ratio (%)

00.5

11.5

22.5

33.5

4

4.55

0.4 0.45 0.5 0.55 0.6Normalised Goodput

Rep_Range=10dBRep_Range=0dB

Potential Congestion Control Gain

Effect of the reporting range value in the LU indicator and potential coordinated congestion control gain.



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-The objectives and main research lines of the AROMA project have been presented

-AROMA focuses on the end-to-end QoS in mobile heterogeneousall-IP networks, integrating solutions for both the radio and thetransport parts.

-For what the radio part concerns, the project focuses on CRRM strategies. Some examples of RAT selection strategies andcommon congestion control algorithms have been presented.

-Concerning the transport network part, a coordinatedradio+transport congestion control mechanism has beenpresented.

ConclusionsConclusions

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AROMA WEB site

http://www.aroma-ist.upc.edu

Thanks for your attention….

AROMA

AROMA

Documents

Advanced Resource Management Solutions for Future All IP ... · Radio Access Network (IP-RAN) UMTS-based Core Network Medium term scenario assumptions: - Backhaul already migrated