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Huawei Confidential

Security Level: Internal

Training Material of

LTE Basics

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Training Objectives

Understanding the LTE architecture(focusing on the EUT!"# side$ and the

structure and function of the LTE %rotocol stac&: !!'L)%hysical layer

Understanding O*+M, the &ey technology of LTE, and the LTE %hysical layer

structure: features of O*+M, -a%%ing relationshi% of %hysical channels, cell

search, and rando- access Understanding the function of LTE %rotocol stac& L) and the %rinci%le and

%rocedure of the L) core scheduling algorith-

Mastering the .uic& calculation of %ea& through%ut /ith different band/idths and

the through%ut analysis in different scenarios

Understanding L0: not -entioned here because a s%eciali1ed training on

accesshandovercall dro% /ill be held later

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Outline

LTE "rchitecture

EUT!"# and S"E "rchitecture

EUT!"# 2rotocol Stac& Structure

LTE 2hysical Layer

Introduction to O*+M

'once%t of LTE 2hysical Layer

Introduction to LTE L)

Introduction to +o/nlin& and U%lin& Scheduling "lgorith-s

+o/nlin& and U%lin& Scheduling 2rocedures

Through%ut 'alculation

Introduction to LTE L0 and Its Service 2rocedure

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LTE "rchitecture: Logical "rchitecture of EUT!"#

%lat a&chitectu&e' The (i!!e)t chan!e of the e*ol*ed acce)) netwo&+ a&chitectu&e i) that the NC i) &emo*ed and it) function i)

-e&fo&med ( the eNode/. The netwo&+ onl t&an)mit) S )e&*ice) and *oice )e&*ice) a&e t&an)mitted ( u)in! 0oI 1inte&2AT o-e&ation i) allowed, )uch a)

CS%/3. S4 inte&face' It i) the inte&face (etween eNode/ and SAE Gatewa566E, includin! the cont&ol -lane and the u)e& -lane inte&face. 7" inte&face' It i) the inte&face (etween eNode/), includin! the cont&ol -lane and the u)e& -lane inte&face, -e&fo&min! the function) of

mo(ilit and -a&t of &adio &e)ou&ce mana!ement. LTE2Uu inte&face' It i) the ai& inte&face (etween eNode/ and UE, includin! the cont&ol -lane and the u)e& -lane inte&face. Itf2S inte&face' It i) the netwo&+ mana!ement inte&face (etween eNode/ and E6S.

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LTE "rchitecture: S"E "rchitecture

The cont&ol -lane and the u)e& -lane a&e )e-a&ate. The 66E function) a) a )in!le node and the GW i) di*ided

into a )e&*in! GW and a DN GW. The two GW) can (e de-loed to!ethe& to o-timi9e the a&chitectu&e. The S4 inte&face u)e) GS Tunnelin! &otocol2U)e& -lane 1GT2U3. The :oS a&chitectu&e &emain) unchan!ed,

that i), diffe&ent (ea&e&) u)e diffe&ent tunnel) 1the LTE u)e) an end2to2end :oS mechani)m.3. The inte&face (etween the 66E and Se&*in! GW i) )tanda&di9ed. 66E and Se&*in! GW can (e de-loed a) one

-h)ical node o& )e-a&ate -h)ical node). The S8 can u)e two -&otocol)' GT o& 6I. The S#, S$ and S44 inte&face) u)e GT.

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LTE 2rotocol Stac&3S4 Interface

S4A' The S4 A--lication &otocol i) the a--lication lae& -&otocol (etween eNode/ and 66E. SCT' The St&eam Cont&ol T&an)mi))ion &otocol en)u&e) the deli*e& of )i!nalin! me))a!e) on the

S4 inte&face (etween the 66E and the eNode/. %o& detail) a(out SCT, )ee %C"

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LTE 2rotocol Stac&35) Interface

The 7" inte&face i) al)o di*ided into the u)e& -lane 17"2U3 and cont&ol -lane 17"2C3. The 7"2U

inte&face i) &eui&ed to (e the )ame a) the S42U, and the 7"2C i) &eui&ed to (e the )ame a) S42C.

The 7" inte&face data lin+ lae& can u)e lae& " technolo!ie), )uch a) and Ethe&net.

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LTE 2rotocol Stac&3Uu Interface

C -&otocol lae& A UE ha) " C )tate).

DC -&otocol lae& LC -&otocol lae& 6AC -&otocol lae& HB -&otocol lae&

L4

L"

L# NAS

U)e& lane Cont&ol lane

CIDLE' A UE i) in CIDLE )tate when the UE doe) not ha*e an

C connection.

D7 can (e u)ed fo& the UE to )a*e the UE -owe&.

The UE monito&) the -a!in! channel.

The UE mea)u&e) the nei!h(o&in! cell and &e)elect) a cell.

The UE !et) ))tem info&mation.

The UE u-date) TAU -e&iodicall.

CCONNECTED' A UE i) in CCONNECTED )tate when at lea)t

one C connection i) e)ta(li)hed fo& the UE.

The UE mana!e) the mo(ilit.

The UE t&an)mit) downlin+ and u-lin+ data.

The UE -&o*ide) channel ualit and feed(ac+ info&mation.

The UE )u--o&t) D7 confi!u&ation to )a*e the UE -owe&.

Int&oduced

late&

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)uita(le fo& )mall (andwidth) )uch a) # 6H9, 4.$ 6H9.

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"s an e7a-%le, the a%%lications of the channels in a co-%lete net/or& access %rocedure are as follo/s: The UE o(tain) the CI and !et) )nch&oni9ed with the eNode/ in the downlin+ on the 2SCH and S2SCH. The downlin+

)nch&oni9ation include) f&ame )nch&oni9ation and )m(ol )nch&oni9ation. The UE !et) ))tem info&mation 1SI/43 on the /CH. 6I/ and SI/4 a&e alwa) )cheduled on the /CH and othe& SI/) a&e

dnamicall )cheduled on DSCH). e&iod) and li)tenin! window) of othe& SI/) a&e (&oadca)t in SI/4. Afte& the UE &ecei*e) SI/4, it +now) the othe& SI/) to (e

&ecei*ed late&. The UE initiate) the &andom acce)) on the ACH and !et) )nch&oni9ed with the eNode/ in the u-lin+. Afte& &andom acce)), the UE &eue)t) u-lin+ )chedulin! on the UCCH. If the&e i) u-lin+ o& downlin+ data to (e t&an)mitted, the UE need) to li)ten to the DCCH to !et info&mation a(out the USCH and

DSCH. Then, the UE )end) data on the USCH and &ecei*e) data on the DSCH.

a!e ";

"%%lication of LTE 2hysical 'hannels

Note' It i) Ku)t a )chematic fi!u&e,

not definin! the )euence.

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LTE 2hysical Layer

a!e "?

Cell Sea&ch and andom Acce))

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Synchroni1ation 'hannel: 'ell Search and +o/nlin& Synchroni1ation

&ima&2)nch&oni9ation channel 12SCH3 and )econda&2)nch&oni9ation channel 1S2SCH3 In the f&euenc domain' The -&ima& )nch&oni9ation )i!nal 1SS3 and )econda&

)nch&oni9ation )i!nal 1SSS3 a&e t&an)mitted in the cent&al )i /), &e!a&dle)) of cell

(andwidth. The )euence len!th in actual ma--in! i) ;#. The &emainin! )u(ca&&ie&) a&e u)ed fo&

-&otection. In the time domain' The -e&iod i) 8 m).

2SCH' The SS i) ma--ed to the la)t O%D6 )m(ol of )lot = and )lot 4=.S2SCH' The SSS i) ma--ed to the la)t (ut one O%D6 )m(ol of )lot = and )lot 4=.

8=$ -h)ical cell ID) 1CI)3 a&e di*ided into 4;@ !&ou-). Each !&ou- ha) th&ee CI).A one2to2one &elation)hi- ei)t) (etween the SSS and each CI !&ou-. So doe) the SS and each CI in

the !&ou-. The UE !et) )nch&oni9ed in the time domain and f&euenc domain with the netwo&+ and o(tain) the CI

( detectin! )nch&oni9ation channel). 1CI F G&ou- ID J # M Cell Id in !&ou-3

efe&ence Si!nal The UE o(tain) the cell S ( mea)u&in! downlin+ &efe&ence )i!nal).

=

Slot

C%ICH

HICH

DCCH

/CHSS SSS

Slot

4 " # $ 8 ; ? @ , the -a7i-u- TBS the UE ca%acity su%%orts is @4A)? bit

6I6O i) u)ed in downlin+. "T" can t&an)mit two codewo&d) 1I of nea&2-oint UE) F ", u)ed in 6I6O3.

Th&ou!h-ut F 84="$ J 4==== J" F 4=" 6(it5)

The UE

ca-a(ilit

limit) the

amount of

data

t&an)mitted

at a time.

LTE U%lin& 2ea& Through%ut 'alculation

( ith a 'o--ercial 'ategor 0 UE$

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(/ith a 'o--ercial 'ategory0 UE$

The eNode/ mea)u&e) the u-lin+ channel. The th&ou!h-ut &eache) the -ea+ and the channel ualit i) !ood. The hi!he)t 6CS, "$,

i) )elected. 1The comme&cial Cate!o&2# UE doe) not )u--o&t ;$:A6 3

The num(e& of /) allocated to the UE i) dete&mined ( the /uffe& Statu) e-o&t 1/S3 )ent f&om the UE. 1The UE onl need) to)end a S to tell the eNode/ a )chedulin! i) needed (efo&e the UE )end) data fo& the fi&)t time.3 In thi) ca)e, the num(e& i)

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How to calculate the th&ou!h-utP The eNode/ e)timate) the channel ualit' The u-lin+ channel ualit i) dete&mined ( mea)u&in! the SIN, and the downlin+ channel ualit i)

dete&mined ( the C:I )ent f&om the UE. The SIN in the u-lin+ o& C:I in the downlin+ need to (e adKu)ted due to the mea)u&ement inaccu&ac, the diffe&ence (etween the channel),

and the dee- fadin!. 1The eNode/ adKu)t) the SIN and C:I (a)ed on AC5NAC and the di)tance f&om the ta&!et *alue of /LE.3 TheeNode/ )elect) the 6CS (a)ed on the channel ualit 1The )-ect&al efficienc de-end) on the 6CS3.

The eNode/ allocate) the /) (a)ed on the amount of data the UE need) to t&an)mit. /a)ed on the 6CS, num(e& of /), and the inde in #G TS #;."4#, the eNode/ dete&mine) the T/S. The th&ou!h-ut i) the &e)ult of

multi-lin! the T/S and the num(e& of )chedulin! time) 1(a)ed on the DCCH indication3.

&o(e and othe& UE lo! tool) out-ut data e*e& )econd. Theo&eticall, the T/S of e*e& milli)econd )hould (e calculated and then addedto!ethe&. What if it cannot (e doneP Actuall, if the mea)u&ement i) -e&fo&med at a )-ecified time -oint, u)in! the a*e&a!e 6CS and num(e& of/) 1)chedulin! time) a&e ta+en into con)ide&ation3 -&o*ided ( &o(e to calculate the th&ou!h-ut i) al)o accu&ate. Ta+e /LE intocon)ide&ation when calculatin! the actual th&ou!h-ut.

I) the downlin+ SIN &elated to C:IP I) the SIN mea)u&ed ( the UE &elated to the th&ou!h-utP It de-end) on the UE -e&fo&mance. Diffe&ent UE) ha*e diffe&ent al!o&ithm) 1the al!o&ithm) ha*e e-e&ienced )ufficient te)t) ( u)in! te)t UE)3.

The -&otocol doe) not define the ma--in! f&om the unadKu)ted SIN to C:I. The th&ou!h-ut2*e&)u)2SIN cu&*e i) diffe&ent in diffe&ent netwo&+). It de-end) on the netwo&+ inte&fe&ence. The cu&*e) of SIN and TH with a

la&!e num(e& of )am-le) a&e con)ide&ed a) &efe&ential. The&e ma (e much diffe&ence (etween the actual th&ou!h-ut and the calculation &e)ult ( mea)u&in! SIN once. The SIN i) o(tained ( onl

mea)u&in! SS). SS) ma not &eflect the channel ualit accu&atel. %o& eam-le, if the int&a2eNode/ nei!h(o&in! cell i) o-en, the TH

dec&ea)e) uic+l. A !ood method i) to chec+ the I/LE. I f the I/LE i) le)) than 4=, the -&oce)) of the eNode/ i) co&&ect. The low th&ou!h-ut i) cau)ed ( the-oo& channel ualit.

*";s in LTE Through%ut 'alculation

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