EE

TS

8316

Wirele

ss

Netw

ork

sF

all

2013

Shanta

nu K

angude

skangude@

lyle

.sm

u.e

du

Lectu

re:

LT

E S

chedulin

g a

nd D

RX

htt

p:/

/lyle

.sm

u.e

du/~

skangude/e

ets

8316.h

tml

Schedulin

g&

Rate

Contr

ol

Schedule

r opera

tion

Sig

nalli

ng o

f schedule

r decis

ions

Measure

ments

to s

upport

schedule

r opera

tion

UL

MA

CS

chedulin

gat

the

UE

D

ete

rmin

es w

hic

h b

eare

rs g

et how

much o

f

the a

llocation a

t th

e U

E

E

ssentially

within

-UE

schedulin

g

W

ork

s o

n g

rants

receiv

ed f

rom

the e

NB

S

imple

r th

an t

he e

NB

based s

chedulin

g

M

AC

tells

RLC

to s

end X

i bits f

rom

logic

al

channel i

S

chedule

r based o

n B

eare

rs Q

oS

requirem

ents

MA

CS

chedulin

gat

the

eN

B

Sig

nific

antly m

ore

com

ple

x t

han a

t U

E

eN

B c

ontr

ols

channe

l usage in b

oth

UL

& D

L

F

acto

rs a

ffecting s

ch

edulin

g

Tra

ffic

volu

me f

or

each b

eare

r at

each U

E

Schedule

UE

s w

ith b

eare

rs h

avin

g b

acklo

g

Q

oS

Requirem

ents

of

each b

eare

r at

each U

E

Priority

Schedule

, as w

ell

as a

llocate

resourc

es in p

roport

ion t

o

QoS

guara

nte

es

R

adio

conditio

ns a

t U

Es

Id

entified t

hro

ugh

M

easure

ments

made a

t th

e e

NB

, and/o

r

M

easure

ments

report

ed b

y t

he U

E

S

chedule

radio

resourc

es a

s p

er

good r

adio

conditio

ns f

or

UE

s

Radio

Resourc

eA

llocations

D

escribed b

y

R

esourc

e B

lock L

ocations

M

odula

tion a

nd

Codin

g S

che

me

C

an b

e v

alid

for

1 T

ransm

it T

ime I

nte

rval (T

TI)

or

Subfr

am

e

Longer

than 1

TT

I

R

equire a

dditio

nal in

form

ation a

llocation t

ime,

allo

cation r

epetition f

acto

r etc

. to

specify

A

lso c

alle

d S

em

i-P

ers

iste

nt

Sch

ed

uli

ng

Pers

iste

nt

Allo

cations?

T

ypic

al 1 T

TI

allo

cations a

re f

or

1 s

ubfr

am

e o

nly

S

uitable

for

burs

ty, unpre

dic

table

, and d

ow

nlo

ad type o

f tr

aff

ic

E

very

new

allo

cation n

eeds indic

ation a

nd c

hannel capacity u

sa

ge

on P

DC

CH

W

hat

if a

n identical allo

cation n

eeds t

o b

e d

one

periodic

ally

?

Som

e b

eare

rs, lik

e f

or

VO

IP, are

periodic

A

nd e

very

packet carr

ies identical am

ount of

data

A

llocation p

att

ern

and s

ize is D

ET

ER

MIN

IST

IC

W

hat

if t

he a

llocation o

verh

ead in P

DC

CH

per

data

octe

t tr

ansfe

rred is A

LS

O h

igh?

V

OIP

exam

ple

: P

ackets

are

sm

all,

and h

appen e

very

20 m

s f

or

a

dete

rmin

istic p

att

ern

and s

ize o

f allo

cation

E

ffic

ien

cy S

olu

tio

n:

All

ocate

on

ce f

or

peri

od

ic

reso

urc

es =

Pers

iste

nt

All

ocati

on

Challe

nges

with

Pers

iste

nt

Allo

cations

R

esourc

e B

lock C

hann

el C

onditio

ns C

hange

A

llocate

d f

requency c

arr

iers

may c

hange t

o h

ave w

ors

e

channel conditio

ns t

han o

ther

Resourc

e B

locks (

RB

s)

M

ay n

eed to m

ove t

he R

B location

M

ay n

eed t

o a

lter

periodic

ity o

f a p

ers

iste

nt

allo

cation o

ver

tim

e

E.g

. V

OIP

sile

nce p

eriods n

eed t

ransm

issio

ns less o

ften

than t

alk

periods

M

ay n

eed t

o s

uspe

nd o

r pause p

ers

iste

nt

allo

cations

Pers

iste

nt

all

ocati

on

s w

ith

th

e a

bo

ve c

han

ges

all

ow

ed

= S

em

i-p

ers

iste

nt

all

ocati

on

s

Dow

nlin

kA

llocations

by

the

eN

B

Dynam

ic a

llocations (

Regula

r allo

cations)

O

n P

DC

CH

for

usage o

f P

DS

CH

P

hysic

al R

B a

nd M

odula

tion C

odin

g S

chem

e

S

em

i-pers

iste

nt

allo

cations

O

nly

for

the f

irst

HA

RQ

tra

nsm

issio

nof

packets

(of

cours

e,

ReT

xs a

re u

npre

dic

table

)

R

RC

defines t

he p

eriodic

ity o

f th

e s

em

i-pers

iste

nt

dow

nlin

k g

rant

P

DC

CH

indic

ate

s w

heth

er

the d

ow

nlin

k g

rant

is a

sem

i-pers

iste

nt

one i.e

. w

heth

er

it c

an b

e im

plic

itly

reused in t

he

follo

win

g T

TIs

accord

ing t

o t

he p

eriodic

ity d

efined b

y R

RC

When n

eeded,

HA

RQ

RE

TX

alw

ays e

xplic

itly

sig

nale

d

via

PD

CC

H

Dow

nlin

kD

ata

:P

DC

CH

-Sem

i-

pers

iste

nt

Inte

ractions

C

ore

concept

PD

CC

H a

lways o

verr

ides s

em

i-

pers

iste

nt

allo

cations

In

the s

ub-f

ram

es w

here

the U

E h

as s

em

ipers

iste

nt

dow

nlin

k r

esourc

e,

if t

he U

E c

annot

find its

C-R

NT

I on

the P

DC

CH

(s),

a d

ow

nlin

k t

ransm

issio

n a

ccord

ing t

o t

he

sem

i-pers

iste

nt

allo

cation t

hat

the U

E h

as b

een a

ssig

ned

in t

he T

TI

is a

ssum

ed

In

sub-f

ram

es w

here

the U

E h

as s

em

i-pers

iste

nt

dow

nlin

k r

esourc

e,

if t

he U

E f

inds its

C-R

NT

I on t

he

PD

CC

H(s

), t

he P

DC

CH

allo

cation o

verr

ides t

he s

em

i-

pers

iste

nt

allo

cation f

or

that

TT

I and t

he U

E d

oes n

ot

decode t

he s

em

i-pers

iste

nt

resourc

es

Uplin

kA

llocations

by

the

eN

B

D

ynam

ic A

llocations (

Regula

r)

Id

entical to

DL d

ynam

ic a

llocation

s

D

one in P

DC

CH

with P

RB

location a

nd M

CS

S

em

i-pers

iste

nt A

llocations (

sim

ilar

to t

he

DL v

ers

ion)

R

RC

defines p

eri

odic

ity

P

DC

CH

indic

ate

s if

the a

llocation is s

em

i-pers

iste

nt

or

not

O

ne d

iffe

rence f

rom

DL:

HA

RQ

for

UL is

Synchro

nous =

> e

ven a

llocatio

ns f

or

retr

ansm

issio

ns c

an b

e I

MP

LIC

IT

Uplin

kD

ata

:P

DC

CH

,S

em

i-pers

iste

nt,

and

Synchro

nous

HA

RQ

Inte

ractions

C

ore

concept:

PD

CC

H a

lways o

verr

ides

In

sub-f

ram

es w

here

UE

has s

em

i-pers

iste

nt U

L r

esourc

e,

if it

cannot

find its

C-R

NT

I on t

he P

DC

CH

(s),

a U

L T

X a

ccord

ing to

the s

em

i-pers

iste

nt allo

cation t

hat

the U

E h

as b

een a

ssig

ned in

the T

TI

can b

e m

ade.

N/W

perf

orm

s d

ecodin

g o

f th

e p

re-d

efine

d

PR

Bs a

ccord

ing t

o the p

re-d

efined M

CS

In

sub-f

ram

es w

here

UE

has s

em

i-pers

iste

nt U

L r

esourc

e,

if it

finds its

C-R

NT

I on t

he P

DC

CH

(s),

the P

DC

CH

allo

cation

overr

ides the p

ers

iste

nt

allo

cation for

that

TT

I and t

he U

Es

TX

follo

ws t

he P

DC

CH

allo

cation,

not

the s

em

ipers

iste

nt

R

eT

xs a

re e

ither

implic

itly

allo

cate

d in w

hic

h c

ase t

he U

E u

ses

the s

em

i-pers

iste

nt uplin

k a

llocation,

or

explic

itly

allo

cate

d v

ia

PD

CC

H(s

) in

whic

h c

ase the U

E d

oes n

ot

follo

w t

he s

em

i-

pers

iste

nt

allo

cation

Measure

ments

toS

upport

Schedulin

g

M

easure

ment re

port

s r

equired fro

m t

he U

E

to s

upport

both

UL a

nd D

L s

chedulin

g b

y

eN

B

T

raff

ic V

olu

me

U

plin

k b

uff

er

sta

tus r

eport

s (

BS

R)

are

needed t

o

pro

vid

e s

upport

for

QoS

-aw

are

packet

schedulin

g

C

hannel conditio

ns a

t variou

s c

arr

iers

C

QI

report

ing f

or

schedulin

g

Buff

er

Sta

tus

Report

s&

Logic

al

ChannelG

oru

ps

T

raff

ic v

olu

me is r

eport

ed in B

uff

er

Sta

tus R

eport

s

(BS

Rs)

T

o s

implif

y B

SR

s,

logic

al channels

are

gro

uped in

to

4 l

og

ical

ch

an

nel

gro

up

s (

LC

G)

R

eport

ing is a

ggre

gate

on e

ach L

CG

E

xam

ple

A

ll w

eb a

nd f

tp c

an b

e in 1

gro

up

A

ll contr

ol and h

igh p

riority

VO

IP in a

noth

er

gro

up

2 f

orm

ats

for

BS

Rs

S

hort

form

at:

Only

1 L

CG

report

ed (

any 1

)

Long f

orm

at:

All

4 L

CG

s r

eport

ed

B

SR

s a

re s

ent

usin

g M

AC

Sig

nalin

g (

as a

gain

st

RR

C s

ignalin

g)

CQ

IR

eport

ing

C

hannel Q

ualit

y I

ndic

ato

r (C

QI)

rep

ort

s indic

ate

the c

onditio

ns a

s s

een in t

he D

L b

y t

he U

E

C

QI

report

s c

an b

e c

onfigure

d t

o b

e s

ent

P

eriodic

, an

d/o

r

A

periodic

C

QI

report

ing is c

on

figure

d b

y t

he

eN

B,

whic

h

assig

ns t

ime/f

requen

cy r

esourc

es f

or

transm

issio

n

If

both

Aperiodic

and P

eriodic

report

schedule

d f

or

the

sam

e s

ubfr

am

e

ON

LY

Aperiodic

one is s

ent

3 t

ypes

W

ideb

an

d,

Mu

ltib

an

d, an

d M

IMO

CQ

I re

po

rt t

yp

es

Periodic

and

Aperiodic

CQ

IR

eport

s

A

periodic

T

he r

eport

is s

chedule

d b

y t

he e

NB

via

the P

DC

CH

T

ransm

itte

d t

ogeth

er

with u

plin

k d

ata

on P

US

CH

P

eriodic

W

hen t

he U

E is a

llocate

d P

US

CH

resourc

es in a

subfr

am

e w

here

a p

eriodic

CQ

I re

port

is c

onfigure

d t

o b

e

sent,

the p

eriodic

CQ

I re

port

is t

ransm

itte

d t

ogeth

er

with

uplin

k d

ata

on t

he P

US

CH

O

therw

ise,

the p

eriodic

CQ

I re

port

s a

re s

ent

on t

he

PU

CC

H

Core

concept:

Try

th

e b

est

to s

end a

ll re

port

s o

n

PU

SC

H

if

not

possib

le,

use P

UC

CH

N

ote

: S

ize a

nd F

orm

at

depends o

n w

heth

er

Aperiodic

/Periodic

an

d w

heth

er

on P

UC

CH

/PU

SC

H

DR

X

A g

ood r

efe

rence a

t:htt

p:/

/ww

w.s

hare

technote

.com

/htm

l/M

AC

_LT

E.h

tml#

DR

X

Follo

win

g f

igure

s a

re s

ourc

ed f

rom

the a

bove U

RL

Dis

continuous

Reception

(DR

X)

N

orm

ally

UE

requir

ed t

o r

ead P

DC

CH

for

allo

cations

in A

LL S

UB

FR

AM

ES

D

RX

is a

pow

ers

ave m

echanis

m w

ith

A

vaila

ble

-Unavaila

ble

RX

cycle

s/p

eriods

Lik

e D

oze/A

wake P

eri

ods in W

ifi P

ow

ers

ave

C

an h

appen in b

oth

RR

C s

tate

s

In R

RC

_ID

LE

: Longer

unavaila

ble

periods,

and p

agin

g

done w

hen

availa

ble

In

RR

C_

CO

NN

EC

TE

D:

Typic

ally

short

er

unavaila

ble

periods,

and C

RN

TI

based r

egula

r allo

cations w

hen

availa

ble

N

o s

pecia

l R

RC

or

MA

C s

tate

s d

esig

na

ted f

or

DR

X

P

er

UE

mechanis

m (

as o

pposed t

o p

er

beare

r)

DR

XD

efinitio

ns

(1/2

)

O

n-d

ura

tio

n:

Dura

tion

in d

ow

nlin

k s

ubfr

am

es t

hat

the U

E w

aits f

or,

aft

er

wakin

g u

p f

rom

DR

X,

to

receiv

e P

DC

CH

s.

If t

he U

E s

uccessfu

lly d

ecod

es a

PD

CC

H,

the U

E s

tays a

wake a

nd s

tart

s t

he inactivity

tim

er

In

acti

vit

y-t

imer:

Dura

tion

in d

ow

nlin

k s

ubfr

am

es t

hat

the U

E w

aits t

o s

uccessfu

lly d

ecode a

PD

CC

H,

from

the last

successfu

l decodin

g o

f a P

DC

CH

, fa

iling

whic

h it

re-e

nte

rs D

RX

. T

he U

E s

hall

resta

rt t

he

inactivity t

imer

follo

win

g a

sin

gle

successfu

l decod

ing

of

a P

DC

CH

for

a f

irst

transm

issio

n o

nly

(i.e.

not

for

retr

ansm

issio

ns)

DR

XB

asic

s

DR

XD

efinitio

ns

(2/2

)

D

RX

Cycle

:T

he d

ura

tion

of

one 'O

N t

ime' +

one

'OF

F t

ime

sh

ort

DR

X-C

ycle

:D

RX

cycle

whic

h c

an b

e

imple

mente

d w

ith

in t

he 'O

FF

' peri

od o

f a long D

RX

Cycle

T

ypic

ally

a f

ew

short

cycle

s m

ay b

e s

et

aft

er

on

tim

e o

f a

long D

RX

cycle

Just

so t

hat

we g

o t

o t

he long

off

period o

nly

aft

er

testing

the w

ate

rs

with n

o a

ctivity in t

he s

hort

DR

X c

ycle

s

d

rxS

ho

rtC

ycle

Tim

er:

The c

onsecu

tive n

um

ber

of

subfr

am

es t

he U

E s

hall

follo

w t

he s

hort

DR

X c

ycle

aft

er

the D

RX

Inactivity T

imer

has e

xpired

DR

XLong

and

Short

Cycle

s

DR

X S

hort

Cycle

s a

re O

ptional, a

nd n

eed t

o b

e c

onfigure

d;

NO

RM

AL D

RX

is t

he L

ON

G D

RX

Forc

ing

UE

toth

eO

ff

Sta

teby

DR

X

Com

mand

MA

CC

ontr

olE

lem

ent

Active

Tim

e

A

cti

ve-t

ime:

Tota

l dura

tion t

hat

the U

E is

aw

ake.

This

inclu

des t

he

O

n-d

ura

tion

of

the D

RX

cycle

T

he t

ime U

E is p

erf

orm

ing c

ontinu

ous r

eception

w

hile

the inactivity t

imer

has n

ot

expired

T

he t

ime U

E is p

erf

orm

ing c

ontinu

ous r

eception

w

hile

waitin

g f

or

a D

L r

etr

ansm

issio

n a

fter

one

HA

RQ

RT

T

M

inim

um

active tim

e is o

f le

ngth

equal to

on-

dura

tion

M

axim

um

is u

ndefined (

infinite)

Sum

mary

U

L a

nd D

L S

chedulin

g in L

TE

S

em

i-pers

iste

nt S

chedulin

g

D

RX