EPL657-Resource Reservation Management

7/26/2019 EPL657-Resource Reservation Management

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1

EPL 657Topic 4 – Radio

Resource Management



2

Lecture Overview

Changing capacity.

Admission control.

Packet scheduling.

Load Control. Resource management.

Power control.

Handover control.



3

Canging Capacit! Resource Management purpose.

nsure planned coverage !or each service. nsure re"uired connection "uality. nsure planned #low$ %locking. &ptimi'e the system usage in run

time.

Real time Resource Managementand &ptimi'ation !unctions. (nter!erence measurements. )o!t capacity utili'ation. )cheduling in radio inter!ace. Actions to load change.

Real time inter!erenceminimi'ation strategies* Handover control. )ervice prioriti'ation. Connection parameter settings. Admission control.



+

"C#M$ radio networ%

contro&

(n ,C-MA o) will %e controlled %y* Radio /etwork Planning. #/etwork Parameters.$ Real time RRM #Radio Resource Management$ operations in R/C 0). Real time power control.

Drift RNC



1

'TR$ Radio inter(ace

protoco& &a!ers he radio inter!ace o! the

RA is layered into threeprotocol layers* Physical Layer #L4$ -ata link Layer #L2$

Radio Link Control #RLC$ Medium Access Control

#MAC$. /etwork Layer #L3$.

the RLC and layer 3protocols are partitioned intwo planes5 namely the serplane and the Control plane.

Control plane5 Layer 3 ispartitioned into su%layerswhere only the lowestsu%layer5 denoted as RadioResource Control #RRC$5terminates in the RA/

RRC

MAC

Layer 1

C

o

n

t r o

l

M

e a

s u

r e m

e n

t s

RRC

MAC

Layer 1

C o

n

t r o

l

M

e

a

s u

r e m

e n

t s

Measurements Report

RLC retransmission control

R

LC RLC

Control Plane Control PlaneUser Plane User Plane

Radio Resource Assignment

UMTS RADIO ACCESS NETWORK USER TERMINAL

Logical Channels

Transport Channels

L3

L2

L1

PDCP PDCP



6

RRM aims and (unctiona&it! Aim

optimi'ation o! the radio inter!ace utili'ation5 considering the di!!erencesamong the di!!erent services5 not only in terms o! o) re"uirements %utalso in terms o! the nature o! the o!!ered tra!!ic5 %it rates5 etc.

he RRM !unctions include* 4. Admission control*

it controls re"uests !or setup and recon!iguration o! radio %earers. 2. Congestion control*

it !aces situations in which the system has reached a congestion status andthere!ore the o) guarantees are at risk due to the evolution o! systemdynamics #mo%ility aspects5 increase in inter!erence5 etc.$.

3. Mechanisms !or the management o! transmission parameters* are devoted to decide the suita%le radio transmission parameters !or each

connection #i.e. 75 target "uality5 power5 etc.$. +. Code management*

!or the downlink it is devoted to manage the &8)7 code tree used to allocatephysical channel orthogonality among di!!erent users.



9

Radio )earer

,henever a certain service should %e

provided under certain guarantees o) a

%earer service with clearly de!ined

characteristics and !unctionality must %e setup !rom the source to the destination o! the

service5 may%e including not only the M)

network %ut also e:ternal networks.



;

RRM metods Connection %ased !unctions.

Handover Control (HC). Handles and makes the handover decisions. Controls the active set o! 0) o! M).

Power Control (PC). Maintains radio link "uality. Minimi'es and controls the power used in radio inter!ace.

/etwork %ased !unctions.

Admission control (AC). Handles all new incoming tra!!ic. Check whether new connection can %e admitted to the

system and generates parameters !or it. &ccurs when new connection is set up as well during handovers and %earer

modi!ication. Load control (LC).

Manages situation when system load e:ceeds the threshold and some countermeasures have to %e taken to get system %ack to a !easi%le load.

Packet scheduler (PS). Handles all non real time tra!!ic5 #packet data users$. (t decides when a packet

transmission is initiated and the %it rate to %e used. Resource ana!er (R).

Controller over logical resources in 0) and R/C and reserves resources in terrestrialnetwork.



<

'TR$ Radio inter(aceprotoco& &a!ers Connections %etween RRC and MAC as well as RRC and L4

provide local inter=layer control services and allow the RRC tocontrol the con!iguration o! the lower layers.

(n the MAC layer5 logical channels are mapped to transportchannels. A transport channel de!ines the way how tra!!ic !romlogical channels is processed and sent to the physical layer.

he smallest entity o! tra!!ic that can %e transmitted through atransport channel is a ransport 0lock #0$. &nce in a certainperiod o! time5 called ransmission ime (nterval #($5 a givennum%er o! 0 will %e delivered to the physical layer in order to

introduce some coding characteristics5 interleaving and ratematching to the radio !rame



4>

,ithin the M) architecture5 RRMalgorithms will %e carried out in the Radio/etwork Controller #R/C$.

-ecisions taken %y RRM algorithms aree:ecuted through Radio 0earer ControlProcedures #a su%set o! Radio ResourceControl Procedures$* 4. Radio 0earer )et=up. 2. Physical Channel Recon!iguration. 3. ransport Channel Recon!iguration.



44

Power Contro& *PC+

(n C-MA=%ased 3? systems all users can share a common !re"uency inter!erence control keep the transmission powers at a minimum level ensure ade"uate signal "uality and level at the receiving end.

&pen=loop PC is responsi%le !or setting the initial L and -L transmission powers when a is accessing the network.

)low PC is applied on the -L common channels.

(nner=loop PC #also called !ast closed=loop power control$

ad@usts the transmission powers dynamically on a 41>> H' %asis. &uter=loop PC

estimates the received "uality and ad@usts the target )(R #)ignal to(nter!erence Ratio$ !or the !ast closed=loop PC so that the re"uired "uality isprovided. #longer time scales than closed loop power control$



42

Open Loop Power Contro&

he L and -L !re"uencies o! ,=C-MA are within the same

!re"uency %and a signi!icant correlation e:ists %etween the average path=loss o!

the two links.

his makes it possi%le !or each prior to accessing thenetwork5 and !or each /ode 0 when the radio link is set up5 to

estimate the initial transmit powers needed in L #!rom to

/ode 0$ and -L %ased #!rom /ode 0 to $ on the path=loss

calculations in the -L direction.



43

'p&in% Open Loop PowerContro& he L open=loop PC !unction is located %oth in the and in the RA/.

0ased on the calculation o! the open=loop PC5 the terminal sets the initial power !or the !irstPhysical Random Access Channel #PRACH$ pream%le and !or the L -edicated PhysicalControl Channel #-PCCH$ %e!ore starting the inner=loop PC.

Preamble_Initial_Power = CPICH_Tx_power - CPICH_RSCP + UL_interference + UL_require_CI RSCP* Received )ignal Code Power

CP"CH* Common Pilot Channel

he same procedure is !ollowed %y the when setting the power level o! the !irst PhysicalCommon Packet Channel #PCPCH$ access pream%le.

,hen esta%lishing the !irst -PCCH5 the starts the L inner=loop PC at a power levelaccording to

!PCCH_Initial_Power = !PCCH_Power_off"et - CPICH_RSCP

CPICH_RSCP is measured %y the terminal.

!PCCH_Power_off"et is calculated %y AC in the R/C and provided to M) during a radio %earer orphysical channel recon!iguration.

!PCCH_Power_off"et = CPICH_Tx_power + UL_interference + )(R-PCCH -#$lo% & )7-P-CH '

)(R-PCCH is the initial target )(R produced %y the AC !or that particular connection )7-P-CH is the spreading !actor o! the corresponding -edicated Physical -ata Channel #-P-CH$.



4+

#own&in% Open Loop PowerContro&

his !unction is located in %oth the RA/ and the (n the -ownlink5 the open=loop PC is used to set the initial power o! the downlink

channels %ased on the -L measurement reports !rom the . A possi%le algorithm !or calculating the initial power value o! the -P-CH when the

!irst hearer service is set up is

R is the user %it rate

#%/o$-L is the -L planned %/o value set during the R/P , isthe chip rate

#c/o$CP(CH

is reported %y the

B is the -L orthogonality !actor

Pt:otal is the carrier power measured at the /ode 0 and

reported to the R/C.

c/o* Ratio o! desired receive power per chip to receive power density in the %and

) _ )/(

_ _ (

)/(Total Ptx

No Ec

power TxCPICH

W

No Eb R P

CPICH

DL Initial Tx •−••= α



41

Power Contro& on #own&in% CommonCanne&s

-etermined %y the network.

he ratio o! the transmit powers %etween di!!erent

downlink common channels is not speci!ied in the

recommendations.

DL common channel #$%ical %ower level Note

P=CP(CHP=)CH and )=)CH

P=CCPCHP(CH A(CH

)=CCPCH

3>=33 d0m =3 d0

=1 d0 =; d0 =; d0 =1 d0

1=4>D o! ma:imum cell : power #2> ,$relative to P=CP(CH power

relative to P=CP(CH power relative to P=CP(CH power and /p E 92power o! one Ac"uisition (ndicator #A($compared to P=CP(CH power relative to P=CP(CH and )7 E 216 #41 k%ps$

CP"CH* Common Pilot Channel



46

,nner Loop Power Contro&

he inner=loop PC relies on the !eed%ack in!ormation at Layer ( his allows the /ode 0 to ad@ust its transmitted power %ased on the received)(R level at the /ode 0 !or compensating the !ading o! the radio channel.

he inner=loop PC !unction in M) is used !or the dedicated channels in %oth theL and -L directions and !or the Common Packet Channel #CPCH$ in L .

(n ,=C-MA !ast PC with a !re"uency o! 4.1 kH' is supported

&'

SRNC

Node

&u

"u

&L outer loo% PC

* S"R + f(L'R or 'R)

* S"R tar!et mana!ement

DC and s%littin!

S"R estimates vs. tar!et S"R&L #PC commands

DL outer loo% PC

* S"R + f(L'R or 'R)* S"R tar!et mana!ement

S"R estimates vs. tar!et S"R

*, DL #PC commands



49

Outer-&oop Power Contro&

he aim o! the outer=loop PC algorithm is to maintain the "uality o! the communication atthe level de!ined %y the "uality re"uirements o! the %earer service in "uestion %y producingade"uate target )(R !or the inner=loop PC.

-one !or each -CH %elonging to the same RRC connection. he !re"uency o! outer= loop PC ranges typically !rom 4> to 4>> H'.

Node

&L -uter Loo% PC'ntit$ /

Calculation o! )(Rtarget change

ransmission o! the new)(R target value to 0)

D C

"u

&L -uter Loo%PC Controller

/ew )(R targetcomputation

LC

AC

"nner loo% PC

New S"R

#ar!et

0ualit$ "nfo

(L'R1'R)

S"R #ar!etmodification

command

New S"R#ar!et

PC parameters atRA0 setupradio linkrecon!iguration

"nitial S"R tar!et

RNC



4;

,nteraction .etween PCa&goritms



4<

/andover */O+

he Handover process is one o! the essential means that guaranteesuser mo%ility in a mo%ile communication network5 %y supportingcontinuity o! service. intra=system handovers

intra=!re"uency inter=!re"uency

inter=system handovers.

,hen a handover occurs5 many RRM mechanisms are triggered otherthan the actual Handover mechanism. AC handles the downlink admission decision #acceptance and "ueuing$ LC updates downlink load in!ormation when a new H& link is admitted P) releases codes !or H& %ranches o! /R and schedules H& addition

re"uests !or /R RM* Activatesdeactivates H& %rances. Allocatesreleases -L spreadingcodes.

he H& mechanism processes the measurements made %y a terminaland makes decisions. (t also updates re!erence transmission powers.



2>

/andover Reasons he %asic reason %ehind a H& is that the air inter!ace does not !ul!il the

desired criteria set !or it anymore and thus either the or the RA/initiates actions in order to improve the connection.

he H& e:ecution criteria depend mainly upon the H& strategyimplemented in the system. Si%nal (ualit)

Constant signal measurements carried out %y %oth the and the /ode 0 aim todetect any signal deterioration.

,hen the "uality or the strength o! the radio signal !alls %elow certain parametersset %y the R/C5 a H& is initiated. his holds !or %oth the L and the -L radio links. Traffic le*el

H& is also initiated when the intra=cell tra!!ic is approaching the ma:imum cellcapacity or a ma:imum threshold.

he H& usually occurs when the approaches the edges o! the cell with highload.

his sort o! H& helps to distri%ute the system load more uni!ormly and to adapt the

needed coverage and capacity e!!iciently meeting the tra!!ic demand within thenetwork.

U"er mobilit) he num%er o! H&s is proportional to the degree o! mo%ility. o avoid undesira%le H&s5 Fs with high motion speed may %e handed over !rom

micro cells to macro cells. (n the same way5 Fs moving slowly or not at all5 can%e handed over !rom macro cells to micro cells.



24

/andover Process

A %asic H& process consists o! threemain phases measurement phase

Intra-frequenc) Inter-frequenc) Traffic *olume (ualit) Internal

decision phase Change o! %est cell. Changes in the )(R level. Changes in the ()CP level. Periodical reporting.

ime=to=trigger. e:ecution phase.

/etwork valuated Handover #/H&$ Mo%ile valuated Handover #MH&$

MA)3RM/

-C()(&/

GC3(&/

Measuremetnt criteria

Measurement reports

Algorith parametersHandover criteria

Handover signalling

Radio Resource Allocation



22

/andover in 'MT0

#4$ #2$ #3$ time

) i g n a l ) t r e n g t h

pper threshold

Lower threshold

Handover Margin

)ignal 0)ignal A

)ummed )ignal

Cell A Cell 0

)ignal A e"uals lower threshold. 0ased on measurements5 R/C

recognises an availa%leneigh%ouring signal #signal 0$5 withade"uate strength to improve"uality o! connection. R/C adds

signal 0 to Active )et. has two simultaneous

connections to RA/ and%ene!its !rom summed signal#signal A 0$

,hen "uality o! signal 0 %ecomes%etter than signal A R/C keeps this as starting point !or

H& margin calculation. )ignal 0 greater than de!ined lower

threshold. strength ade"uate to satis!y

re"uired o). strength o! summed signal e:ceeds

de!ined upper threshold5 causingadditional inter!erence. R/Cdeletes signal A !rom Active )et.

Handover Algorithm

Assumption* a 5 currently connected tosignal A5 is located in cell A and moving

towards cell 0.

Pilot signal A5 deteriorates5 approaching

lower threshold Handover riggering



23

0imu&ation eamp&e usingOP2ET /andover 0cenarios

*13+

UE moving

between twoNode B’s

Objective: Conduct a performance comparisonbetween soft and hard handover.

Soft vs. ard andover Scenario



2+

0imu&ation eamp&e usingOP2ET /andover 0cenarios

*3+ !esu"ts:

#pp"icationresponse time: Nosignificantdifference between

soft and hard.Up"in$

%ransmission &owerof the &h'sica"Channe"s: softhandover produces

better resu"ts.

Simu"ation(E)O



21

/andover T!pes *13+ )o!t Handover

akes place when a new connection is esta%lished %e!ore the old connection is released. (n )o!t H& the neigh%ouring /ode 0 involved in the H& transmits on the same !re"uency. )o!t H& is per!ormed %etween two cells %elonging to di!!erent /ode 0Fs %ut not necessarily on the

same R/C. he R/C involved in the )o!t H& must co=ordinate the e:ecution o! the )o!t H& over the(ur inter!ace.

)o!ter Handover ,hen a new signal is either added to or deleted !rom the Active )et5 or replaced %y a stronger signal

within the di!!erent sectors under the same /ode 0 he /ode 0 transmits through one sector %ut receives !rom more than one sector.

)o!t=)o!ter Handover ,hen so!t and so!ter H&s occur simultaneously. A so!t=so!ter H& may occur !or instance5 in association with inter=R/C H&5 while an inter=sector

signal is added to the Fs Active )et along with adding a new signal via another cell controller %yanother R/C.

)ector 4

!4

)ector 2

!4

0

)

)ector 3

!4

Multipath signal

through )ector 4 Multipath signalthrough )ector 3

7re"uency

!4

7re"uency

!4

0) 0)

#a$ #%$



26

/andover T!pes *3+

Hard Handover -uring the H& process5 the old connection is released %e!ore making a new connection. Lack o! simultaneous signals 8ery short cut in the connection5 which is not distinguisha%le !or the mo%ile user. (nter=!re"uency hard handover

the carrier !re"uency o! the new radio access is di!!erent !rom the old carrier !re"uency to whichthe is connected.

(ntra=!re"uency hard handover the new carrier5 to which the is accessed a!ter the H& procedure is the same as the original

carrier

7re"uency

!4

7re"uency

!4

0) 0)

#a$ #%$

R/CR/C

"ur

7re"uency

!4

7re"uency

!2

0) 0)



29

/andover and Power Contro&Resu&ts

Cell 2

Cell 3

Cell //

Cell /4



2;

$dmission Contro& *$C+

-ecides whether new Radio Access 0earer #RA0$ is admitted or not. Real=ime tra!!ic admission to the network is decided. /on=Real=ime tra!!ic a!ter RA0 has %een admitted the optimum scheduling

is determined. sed when the %earer is

)et up.

Modi!ied -uring the handover.

stimates the load and !ills the system up to the limit. sed to guarantee the sta%ility o! the network and to achieve high

network capacity. )eparates admission !or L and -L.

Load change estimation is done in the own and neigh%ouring cells. RA0 admitted i! the resources in %oth links can %e guaranteed. (n decision procedure AC will use thresholds set during radio network

planning. he !unctionality located in the RRM o! the R/C.



2<

Throughput based CAC (TCAC)

,ith CAC algorithm5 admission decisions are taken %ased onthe capacity re"uired %y the re"uesting call in con@unction withcurrent capacity usage due to ongoing connections.

he condition that needs to %e met !or new connectionadmission is that aggregate throughput in %oth directions o! the

wireless link #uplink and downlink$ does not e:ceed certainrespective ma:imum thresholds and there!ore smooth networkoperation is ensured.

?iven the o) re"uirements o! the new connection in terms o!data rate and 0LR as well as the applied ,C-MA encoding

type #e.g convolutional codes$ and rate #e.g hal!third rate$5 it ispossi%le to compute the load increase that would occur shouldthe connection %e esta%lished using #4$ and #2$



3>

Throughput based CAC (TCAC)

( ) ( )

( ) ( )

10 10

10 10

1 0.35 log log half rate1.1

(!")1

0.# log log thir! rate1.5$

SDU b

oSDU

length BLER E

N length BLER

× + − =

× − + −

( )

3.0

10.0

3.0

10.0

% &plin'

1

10

10 % !onlin'

b o

b o

f

E N

UL

E N DL

f

d

W

Load increae S!" R

Rd S!"

W

+

+

+= × ×

+ × × × ÷ ÷

α



34

where* b,o )ignal energy per %it divided %y noise spectral density to

meet prede!ined o) Len%t. S!U he time length o! a )ervice -ata nit

/LR he re"uested 0Lock rror Rate !or the service d -ownlink other=cell inter!erence !actor computed at the edge o!

the cell 0 -ownlink spreading codesF orthogonality !actor 1 ,C-MA chip rate #3.;+ Mcps$

R UL Re"uested service data rate in the uplink direction R !L Re"uested service data rate in the downlink direction S23 )ervice activity !actor #4.> !or real=time interactive services

like voice and video telephony5 I 4.> !or data applications$



32

Trougput .ased $dmissionContro& (n throughput=%ased admission control the strategy is that a new %earer is admitted only i!

the total load a!ter admittance stays %elow the thresholds de!ined %y the R/P.

(n the L the !ollowing e"uation must %e !ul!illed

(n the -L the must %e !ul!illed

he L Load 7actor is o%tained using

he -L Load 7actor is o%tained using

o o%tain the load increase caused %y the new user

threhold ULUL L _ η η ≤∆+

threhold DL DL L _ η η ≤∆+

C

N

C

I C

I

PN Ioth Iown

Ioth Iown

xTotal

Ioth IownUL

+⇔

++

+⇔

+=

Pr η

ν ρ ..1

1

R

w L

+=∆

)a*1

Rx

R# N

$ DL

∑==η



33

"ide.and Power .ased $dmissionContro& he L admission decision is %ased on cell=speci!ic load thresholds given %y the R/P. A R

%earer will %e accepted i! the non=controlla%le L load5 PrxC 5 !ul!ils*

and the total received wide%and inter!erence power PrxTotal !ul!ils*

Power increase is o%tain using

where is the uplink L7 and can %e o%tain using

he !ractional load o! the new user can %e calculated using

7or the -L direction a similar admission algorithm is de!ined

et xT I xNC argPr Pr ≤∆+

x%ffet et xT xTotal Pr argPr Pr +≤

L xTotal I ∆−

≈∆ .1

Pr η

xTotal

Ioth IownUL

Pr

+=η

η

ν ρ ..1

1

R

w L

+=∆



3+

Logica& #ependencies o( $C AC has some logical dependencies due to its interworking with the rest o! the

RRM mechanisms. receives load in!ormation !rom P) and LC. receives in!ormation a%out the active set !rom the HC sends P) in!ormation a%out the radio %earers. sends load changes in!ormations to LC. sends the target values !or 0R5 0LR and )(R to PC



31

Load Contro& *LC+ he purpose o! the LC mechanism is to increase the capacity o! a cell and

prevent overload continuously measures uplink and downlink inter!erence (n an overload condition5 reduces the load and %rings the network %ack into operating

state normal state

the power received in the uplink and the transmitted power in the downlink are a targetvalue which is the optimal average o! the Pr:otal and Pt:otal !or the uplink anddownlink.

preventive state the Pr:otal in the uplink and Pt:otal in the downlink are %elow Pr:arget and

Pt:arget respectively5 plus an &!!set value which e"uals the ma:imum margin %ywhich the target value can %e e:ceeded.

LC ensures that the network is not overloaded and remains sta%le overload state

Anything a%ove the preventive state

LC is responsi%le !or reducing the load and %ringing the network %ack into operatingstate. he actions that can %e taken with the o%@ective o! reducing the load are* Actions !or !ast LC located in the /ode 0*

-enying the -L or overriding the L ransmit Power JupK commands. Lowering the re!erence )(R !or the inner=loop PC in the L.

Actions !or LC located in the R/C* (nteracting with the Packet )cheduler and reducing the packet data tra!!ic. Reducing the %it rates o! R users5 e.g.5 voice services.



36

Power )ased LC a&goritmS Re%orts

Pr5#otal

RNC &%dates

Cell Load

'5ceeds

Pr1t5 tar!et

Load Control Checks

Cell Load

No Actions

No

'5ceeds Pr1t5 tar!et

6 Pr1t5 -ffset

Preventive Actions

PS and AC7ast LC actions in #S8

* Den$ (DL) or overwrite (&L) #5 Power

Control 9u%9 commands.

* Lower S"R tar!et for &L inner loo% PC.

LC actions located in the RNC8* "nteract with PS and throttle ack %acket

data traffic.

* Lower it rates of R# users.

* Dro% sin!le calls in a controlled manner.

No

:es

:es



39

Pac%et 0cedu&ing

he Packet )cheduling controls the M) packet access and is located in theR/C. he !unctions o! the P) are* o determine the availa%le radio inter!ace resources !or /on Real ime radio %earers. o share the availa%le radio inter!ace resources %etween /on Real ime radio %earers. o monitor the allocation !or /on Real ime. o initiate transport channel type switching %etween common and dedicated channels

when necessary. o monitor the system loading. o per!orm LC actions !or /on Real ime radio %earers when necessary.

AC and P) %oth participate in the handling o! /on Real ime radio %earers. AC takes care o! admission and release o! radio access %earers #RA0s$.

Radio resources are not reserved !or the whole duration o! the connection %ut only when there isactual data to transmit.

P) allocates appropriate radio resources !or the duration o! a packet call5 i.e.5 activedata transmission.

P) is done on a cell %asis. )ince asymmetric tra!!ic is supported and the load may vary a lot %etween L and -L5

capacity is allocated separately !or %oth directions.



3;

Pac%et 0cedu&ing

he cellFs radio resources are shared %etween R and /R radio %earers. he proportion o! R and /R tra!!ic !luctuates rapidly. A characteristic o! the load caused %y R tra!!ic is that it cannot %e e!!iciently

controlled. he load caused %y R tra!!ic5 inter!erence !rom other cell users and noise5 is called

/on=controlla%le load. he remaining !ree capacity !rom the Planned arget Load can %e used !or /R radio

%earers on a %est e!!ort %asis. he load caused %y %est e!!ort /R tra!!ic is called the Controlla%le load.

Load

time

7ree capacity5 which can %e

allowed !or controlla%le load

on %est e!!ort %asis

/on controlla%le load

Planned #ar!et Load



3<

P0 - Time #ivision0cedu&ing ime -ivision )cheduling

he availa%le capacity is allocated to one or very !ew radio %earers at a time. he allocated %it rate can %e very high and the time needed to trans!er the data in the

%u!!er is short. he allocation time can %e limited %y setting the ma:imum allocation time5 which prevents

one high %it rate user !rom %locking others. )cheduling delay depends on load5 so that the waiting time %e!ore a user can transmit data

is longer when the num%er o! users is higher.

ime division scheduling is typically used !or -)CH where the scheduling o! P-)CH canhappen on a resolution o! one 4>ms radio !rame5 %ut it can also utilised !or -CHscheduling.

%it rate

time

%it rate

time



+>

P0 - Code #ivision0cedu&ing he availa%le capacity is shared %etween large num%ers o! radio %earers5

allocating low %it rate simultaneously !or each user. (n code=division scheduling all users are allocated a channel when they need it.

Allocated %it rates depend on load5 so that the %it rates are lower when thenum%er o! users is higher.

sta%lishment and release delays cause smaller losses in capacity due to thelower %it rates and long time transmissions.

-ue to the lower %it rate5 allocation o! resources takes longer in code divisionscheduling than in time division scheduling. air inter!ace inter!erences levels are more predicta%le and can %e seen as an advantage

!or code division scheduling.

%it rate

&ser /

&ser ;

&ser <

&ser =

time

%it rate

&ser /

&ser ;

&ser <

&ser =

time



+4

P0 - Transmission Power .ased

0cedu&ing he allocated packet data rate could %e %ased on the re"uired

transmission power o! the connection Higher %it rates !or a users re"uiring less transmission power per

transmitted %it. Minimi'ation o! the average re"uired transmission power per %it5 the transmitted inter!erence generated in the network5 increase o! the average cell throughput compared to e"ual %it rate scheduling.

ransmission power %ased scheduling gives more gain in theaverage throughput in -L than in L compared to e"ual %it ratescheduling. (n the L5 typically at least 1>D o! the inter!erence originates !rom the

users within the same cell5 and that inter!erence does not depend on thetransmission power %ut only on the received powers. (n the -L the transmission power %ased scheduling can clearly increase

the average -L throughput.



+2

P0 - Pac%et 0cedu&ing wit o0#ierentiation and Round Ro.in

Packet )cheduling with o) -i!!erentiation his algorithm is %ased on the di!!erentiation o! users in terms o! o)

the network operators will %e a%le to o!!er di!!erent services to the users.

he knowledge o! the Carrier over (nter!erence #C($ can increase the C-MA capacity%y transmitting mostly when channel conditions are !avoura%le

0y giving certain users and services high priority5 the capacity o! the system is increasedat the e:pense o! degraded o) !or the rest o! the users.

Round Ro%in sers get an e"ual share o! the radio resources and the o) will %e !airer distri%uted

among them. (n order to get the o) 4>>D !airly distri%uted among users5 the users in degraded

conditions should get a larger share o! the resources than users in good conditions. his is the inverse C( scheduling. 0y taking the radio conditions into account one can

modi!y the P)5 so that it goes !rom %eing C( %ased to inverse C( %ased.



+3

,nterwor%ing actions o( $C P0and LC

(n uplink. Pr5#ar!et5 the optimal average PrxTotal Pr5-ffset5 the ma:imum margin %y which PrxTar%et can %e e:ceeded.

(n downlink. Pt5#ar!et 5 the optimal average !or PtxTotal . Pt5-ffset 5 the ma:imum margin %y which PtxTar%et can %e e:ceeded.



++

Resource Management *RM+

Purpose* to allocate physical radio resources when re"uested %ythe RRC layer.

nows radio network con!iguration and state data. )ees only logical radio resources.

Allocation is a reservation o! proportion o! the availa%le radio

resources according to the channel re"uest !rom RRC layer !oreach radio connection.

(nput comes !rom ACP). RM in!orms P) a%out network conditions. Allocates scram%ling codes in L.

Allocates the spreading codes in downlink direction. A%le to switch codes and code types

-uring so!t handover. -e!ragmentation o! code tree.



RRMs8 Recommended,ntroductor! Reading Chr+sosto)os has the list of the papers

Documents

EPL657-Resource Reservation Management