Cu so: 2022 - 2023
Di ec o /Di ec o a: Anguei a Buce a, Pablo
Codi ec o /Codi ec o a: Mon albán Sanchez, Jon
Es udian e
: Jiménez Acedo, E ick
MEDIA DELIVERY
HARMONIZATION OVER DIGITAL
TERRESTRIAL TELEVISION (DTT)
AND 5G NETWORKS
MÁSTER UNIVERSITARIO EN INGENIERÍA DE
TELECOMUNICACIÓN
TRABAJO FIN DE MASTER
Fecha: Bilbao, 18, sep iemb e, 2023
Con en s
1 In oduc ion 10
1.1 Technical Ad ances on Mobile Ne wo ks . . . . . . . . . . . . . . . . . . . 11
1.2 Technical Ad ances on B oadcas Ne wo ks . . . . . . . . . . . . . . . . . . 12
1.3 Mo i a ion.................................... 12
2 Objec i es 14
3 Con ibu ion o SDG 15
4 S a e o he A 16
4.1 Mobilene wo ks................................. 16
4.1.1 5GA chi ec u e............................. 17
4.1.2 Key ea u es o e e y 5G Release . . . . . . . . . . . . . . . . . . . 33
4.2 B oadcas Ne wo ks............................... 36
4.2.1 ATSC3.0 ................................ 36
4.3 Con e gence be ween B oadcas and B oadband sys ems . . . . . . . . . . 40
5 Me hodology 44
5.1 Phase 1: P ojec de ini ion and S a e o he A s udy . . . . . . . . . . . 44
5.2 Phase 2: Speci ica ions s udy and implemen a ion o selec ed 5G equipmen 44
5.3 Phase 3: Adap a ion o an ATSC ne wo k simula ion model . . . . . . . . 46
5.4
Phase 4: Design and Implemen a ion o a Con e gen A chi ec u e be ween
ATSCand5G.................................. 49
5.5 Phase 5: Simula ion and analysis o con e gen use cases . . . . . . . . . . 49
6 A chi ec u es o 5GS and E alua ion P ocedu e 51
6.1 AApp oach................................... 51
6.1.1 T oubleshoo ing............................. 51
6.2 BApp oach................................... 54
6.2.1 T oubleshoo ing............................. 55
7 A chi ec u e o ATSC 3.0 and E alua ion P ocedu e 57
7.1 O iginalp o o ype ............................... 57
7.2 Adap edsolu ion ................................ 59
8 A chi ec u es o a Con e gen Sys em and E alua ion P ocedu e 63
8.1 KPIp ocessing ................................. 64
9 Resul s and Discussions 66
9.1 UE Mobili y and QoE deg ada ion . . . . . . . . . . . . . . . . . . . . . . 67
9.2 Delay and QoE Deg ada ion . . . . . . . . . . . . . . . . . . . . . . . . . . 71
10 P ojec Planning 73
10.1 Wo k Packages and Tasks . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
10.2Gan Cha ................................... 74
11 Conclusions 76
12 Bibliog aphy 77
Lis o Figu es
1 O iginal 3GPP 5G de elopmen oadmap. . . . . . . . . . . . . . . . . . . 11
2 ATSC 3.0 p o ocol s ack [4]. . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3 Non s and-alone a chi ec u e [6]. . . . . . . . . . . . . . . . . . . . . . . . 18
4 5GC isualized wi h Se ice-Based in e aces [6]. . . . . . . . . . . . . . . . 21
5 5GC isualized wi h poin - o-poin in e aces [6] . . . . . . . . . . . . . . . 22
6 PCF Se ice Regis a ion. . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
7 AMFSe iceDisco e y. ............................ 23
8 AMF Se ice Reques and p e ious s ages. . . . . . . . . . . . . . . . . . . 23
9 Simple 5GC e sion wi h obliga o y componen s. . . . . . . . . . . . . . . 24
10 UE se ed by a pai o SMF/UPF. . . . . . . . . . . . . . . . . . . . . . . 26
11 IPmobili y. ................................... 27
12
En i ies in ol ed in use plane connec ion o adio ne wo ks and ex e nal
ne wo ks. .................................... 27
13 Connec ions be ween he de ice and he CN o non-3GPP access. . . . . . 28
14 5G adio ne wo k a chi ec u e. . . . . . . . . . . . . . . . . . . . . . . . . . 29
15 5G adio p o ocol s ack. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
16 Ne wo k-in e nal signaling p o ocol s ack. . . . . . . . . . . . . . . . . . . 30
17 Ai in e ace p o ocol s ack. . . . . . . . . . . . . . . . . . . . . . . . . . . 31
18 Resou ce alloca ion o h ee di e en de ices. . . . . . . . . . . . . . . . . 31
19 SDAP p o ocol s uc u e [13]. . . . . . . . . . . . . . . . . . . . . . . . . . 34
20 5G Mul icas a ic example. . . . . . . . . . . . . . . . . . . . . . . . . . 35
21 5G B oadcas a ic example. . . . . . . . . . . . . . . . . . . . . . . . . . 35
22 ATSC 3.0 laye ed s uc u e. . . . . . . . . . . . . . . . . . . . . . . . . . . 36
23 ATSC 3.0 documen s s uc u e. . . . . . . . . . . . . . . . . . . . . . . . . 37
24 ATSC 3.0 ecei e p o ocol s ack. . . . . . . . . . . . . . . . . . . . . . . . 38
25 UMLDiag am. ................................. 39
26
Example o sepa a e ROUTE sessions/PLPs o di e en ia e QoS o ideo
andaudio..................................... 40
27 IP-based coope a i e se ices using ATSC 3.0 and B oadband [17]. . . . . . 42
28 ATSSS unc ionali y included in he 5GS [18]. . . . . . . . . . . . . . . . . 43
29 Ama iCallboxClassic.............................. 45
30 DekTec DTU-315 Modula o . . . . . . . . . . . . . . . . . . . . . . . . . . 47
31 DekTec DTA-2131 Recei e . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
32 T i eni GuideBuilde MPD Injes . . . . . . . . . . . . . . . . . . . . . . . . 48
33 T i eni GuideBuilde ROUTE T ansmi . . . . . . . . . . . . . . . . . . . . 48
34 Ini ial 5G a chi ec u e design. . . . . . . . . . . . . . . . . . . . . . . . . . 51
35 5G SA Success ul Regis a ion P ocess. . . . . . . . . . . . . . . . . . . . . 52
36 PDU Session Es ablishmen Accep message and alloca ed IP add esses. . . 53
37 Final 5G a chi ec u e design. . . . . . . . . . . . . . . . . . . . . . . . . . . 54
38 APNCon igu a ion................................ 55
39 Quec el 5G-M2 EVB Ki . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
40 DTT and mobile legacy a chi ec u es o p opose BCN o u u e DTT. . . 57
41 En isioned a chi ec u e o a DTT ne wo k con aining a BCN. . . . . . . . 59
42 Guidebuilde Se ice Ne wo k Map. . . . . . . . . . . . . . . . . . . . . . 60
43 Logical Ne wo ks con igu a ion. . . . . . . . . . . . . . . . . . . . . . . . . 61
44 Physical T anspo con igu a ion. . . . . . . . . . . . . . . . . . . . . . . . 61
45 Ou pu con igu a ion............................... 62
46 Adap ed DTT a chi ec u e. . . . . . . . . . . . . . . . . . . . . . . . . . . 62
47 Final con e gen a chi ec u e design. . . . . . . . . . . . . . . . . . . . . . 63
48 Ama iso logexample. ............................ 64
49 P ocessed Ama iso log example. . . . . . . . . . . . . . . . . . . . . . . . 64
50 DL bi a e alues o he sample ideo. . . . . . . . . . . . . . . . . . . . . 67
51 Bi a e downg ade Tes I. . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
52 Bi a e downg ade Tes II. . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
53 VLCS alling. .................................. 69
54 Use Case Analysis - Bi a e Downg ade (Kbps), Tes I. . . . . . . . . . . . 70
55 Use Case Analysis - Bi a e Downg ade (Kbps), Tes II. . . . . . . . . . . . 70
56 Use Case Analysis - Delay/Ji e In oduc ion. . . . . . . . . . . . . . . . . 72
57 Gan Cha . .................................. 75
Lis o ables
1 E olu ion o he a e age sma phone use ’s da a consump ion [1]. . . . . . 10
2 Possible combina ions o 5G adio and co e ne wo ks. . . . . . . . . . . . . 18
3 Ad an ages o using a sma phone o a 5G ou e . . . . . . . . . . . . . . . 56
Ac onyms
3GPP 3 d Gene a ion Pa ne ship P ojec
IETF In e ne Enginee ing Task Fo ce
ITU In e na ional Telecommunica ion Union
QoS Quali y o Se ice
QoE Quali y o Expe ience
OTT O e - he- op
CDN Con en Deli e y Ne wo ks
IP In e ne P o ocol
NR New Radio
SBA Se ice Based A chi ec u e
MBS Mul icas and B oadcas Se ices
ATSC Ad anced Tele ision Sys ems Commi ee
DTT Digi al Te es ial Tele ision
RAN Radio Access Ne wo k
RAT Radio Access Technology
NF Ne wo k Func ion
CN Co e Ne wo k
5GC 5G Co e
5GS 5G Sys em
5G SA 5G S andalone
5G NSA 5G Non-S andalone
PTP Poin - o-poin
PTM Poin - o-mul ipoin
DASH Dynamic Adap a i e S eaming o e HTTP
ROUTE Real-Time Objec Deli e y o e Unidi ec ional T anspo
Resumen
La popula idad del s eaming de con enidos mul imedia ha c ecido conside ablemen e
en los ´ul imos a˜nos, con i i´endose en un componen e impo an e del ´a ico dia io en
In e ne . Incluso se p e ´e que pa a el a˜no 2024 el ´a ico de ´ıdeo sea el esponsable
del 74% del ´a ico dia io de un sma phone. Es e inc emen o es debido a azones como
mayo es iempo de isionado, un ca ´alogo mas ex enso y mayo es esoluciones. Adem´as,
el desa ollo de nue as aplicaciones con un g an equisi o compu acional, como puede se
la Realidad Aumen ada (RA), Realidad Vi ual (VR) o la Telep esencia Holog ´a ica es ´a
con ibuyendo a´un m´as a dicho inc emen o. Es po es a az´on que es necesa io mejo a las
a qui ec u as cl´asicas de ele on´ıa pa a consegui m´e odos de dis ibuci´on m´as e icien es y
pode cumpli con los equisi os de calidad de los usua ios. Teniendo es o como obje i o,
es e p oyec o p e ende explo a la con e gencia de las edes de TDT y de ele on´ıa 5G
pa a consegui un esquema que abaje de o ma coope a i a. El abajo iene como base
la u ilizaci´on de los ´ul imos a ances en las edes pun o a mul ipun o de TDT, es deci , la
ansici´on hacia un pa adigma IP, pa a la ha monizaci´on con las a qui ec u as de banda
ancha 5G. Como esul ado inal, es e abajo no solo ha pe mi ido la c eaci´on de un banco
de p uebas con e gen e sob e el que abaja en el labo a o io, sino que ha demos ado
compo amien os y pa ones muy in e esan es en los casos de uso es udiados.
7
Labu pena
Mul imedia edukien s eaming-a en ospea naba men hazi da azken u eo an, e a
In e ne eko egune oko a ikoa en osagai ga an zi su ba bihu u da. 2024 ako sma phone
ba en egune oko a ikoa en % 74a en a du aduna bideo- a ikoa iza ea e e au eikus en da.
Hazkunde ho i ikus eko denbo a gehiago, ka alogo zabalagoa e a be eizmen handiagoak
di ela-e a ge a u da. Gaine a, konpu azio-be ekizun handia du en aplikazio be ien ga a-
penak, hala nola E eali a e A eago ua (RA), E eali a e Bi uala (EB) edo Telep esen zia
Holog a ikoa, a e gehiago lagun zen du gehikun za ho e an. Ho ega ik, beha ezkoa da
ele oniako a ki ek u a klasikoak hobe zea, banake a-me odo e aginko agoak lo zeko e a
e abil zaileen kali a e-baldin zak be e ahal iza eko. Helbu u ho i izanik, p oiek u honek
LTDko e a 5G ele oniako sa een konbe gen zia az e u nahi du, modu koope a iboan
lan egingo duen eskema ba lo zeko. Lana en oina ia da LTDko pun u-pun u ani zeko
sa ee ako azken au e apenak e abil zea, hau da, IP pa adigma ba e anzko an sizioa,
5G banda zabaleko a ki ek u ekin ha moniza zeko. Azken emai za gisa, lan honek labo-
a egian lan egi eko p oba-banku konbe gen e ba so zea ahalbide zeaz gain, az e u ako
e abile a-kasue an oso po ae a e a e edu in e esga iak e aku si di u.
8
3 Con ibu ion o SDG
Apa om he clea economic and echnical bene i s ha his p ojec p o ides, i
also con ibu es posi i ely o he Sus ainable De elopmen Goals (SDG) in a ious aspec s.
Addi ionally, his p ojec a ge s he g ow h o he ICT indus y, which is signi ican
o he Eu opean GDP. Ha moniza ion o con e gence be ween 5G and DTT enhances
communi y s eaming se ices aligning wi h se e al SDGs:
•
SDG 4: Quali y Educa ion. Imp o ed access o s eaming se ices can con ibu e
o online educa ional esou ces, p omo ing quali y educa ion.
•
SDG 9: Indus y, Inno a ion and In as uc u e. This p ojec aims o b idge
5G and DTT ne wo ks, achie ing inno a ion and con ibu ing o he de elopmen o
inclusi e and sus ainable in as uc u e.
•
SDG 10: Reduced Inequali ies. P o iding be e access o s eaming se ices
can help educe inequali ies in access o con en and in o ma ion.
•
SDG 11: Sus ainable Ci ies and Communi ies. This endea o , along wi h
ne wo k collabo a ion, has he po en ial o esul in communi ies ha a e be e
in o med and in e connec ed. This aligns wi h he goal’s emphasis on p omo ing
sus ainable u ban de elopmen .
•
SDG 17: Pa ne ship o he Goals. Collabo a ing be ween di e en ne wo k
sec o s showcases pa ne ships o echnological ad ancemen s ha can bene i
socie y.
15
4 S a e o he A
A ho ough examina ion o he p ojec p eceden s is essen ial o h ee main easons:
•
To unde s and he con ex o he p oblem and es ablish he con ibu o ’s knowledge
abou he subjec . In wha scope does he issue all? Do I possess he app op ia e
knowledge o i s esolu ion?
•
To explo e po en ial solu ions o he p oblem. A e he e exis ing solu ions o he
posed issue? Wha ad ancemen s a e being made in he ield o s udy? Wha
bene i s could he p oposed solu ion o e ?
•
To iden i y he app op ia e ools. Once a gene al idea o he p oblem’s esolu ion is
o med, wha ools a e a ailable o add ess he p oblem? Is a solu ion easible wi h
he esou ces a hand?
All hese subjec s mus be esol ed in he ini ial phases o he wo k plan in o de o
ensu e a sa is ac o y ou come o he p ojec . None heless, i is also possible o change
some o he ini ial hypo heses du ing he p ojec ’s ad ancemen .
In his sec ion, i s ly, a s udy has been conduc ed in he ield o mobile communi-
ca ions. As p e iously men ioned, 3GPP has e ol ed h ough se e al e sions and aims
o enhance he o e all pe o mance o 5G wi h u u e de elopmen s. In his s udy, he
ocus is placed on examining hei impac on mul imedia s eaming. Fu he mo e, i is
also impo an o comp ehend he 5G a chi ec u e, he NR concep , and he p omising
SBA o 5G. Ha ing knowledge o he di e en Ne wo k Func ions (NFs) is c ucial o
unde s anding how he CN ope a es.
Secondly, a e esea ch on his ield has been pe o med, he main conce n was he
ansi ion o DTT sys ems o a ull IP s ack. Mo e p ecisely, in his wo k a en ion is
gi en o ATSC 3.0 due o he amilia iza ion and collabo a ion o he esea ch g oup wi h
his s anda d, as well as he possibili y o es ing he esul s wi h labo a o y ha dwa e.
ATSC’s ema kable s ides in inno a ion a e al eady widely acknowledged, ma ked by i s
p omising a chi ec u e. As a esul , he las pa o his sec ion is dedica ed o explo ing
he con e gence o bo h ATSC 3.0 and 5G, acili a ed by hei connec ion in he lowe
laye s o b oadband and b oadcas sys ems [5].
Finally, a e s udying bo h sys ems, we make a inal e o o unde s and he
ini ia i es aken o achie e ha moniza ion and con e gence be ween he wo a chi ec u es.
4.1 Mobile ne wo ks
To begin wi h, i is wo h no ing ha he p ima y e e ence o his po ion o
he s udy has been he book ’5G CORE NETWORKS Powe ing Digi aliza ion’ [6] by
S e an Rommme , e al. This book was w i en based on di e en echnical documen s
such as Technical Repo s, Technical Speci ica ions, Recommenda ions, o RFCs om
di e en o ganiza ions like 3GPP, IETF, ITU, o ITU-R. I ho oughly explains he main
componen s o he 5GS and is highly de ailed in key ea u es like o example, NR, SBA,
connec i i y p ocedu es, o NF- ela ed concep s. Addi ionally, i p o ides compa isons
16
wi h he p e ious gene a ion (LTE) in o de o unde s and new ideas mo e easily. In
conclusion, his book se es as a aluable e e ence and guide o unde s anding 5G on i s
own.
While he design o he 5GC emains a cen al ea u e, he d i ing o ces behind 5G
ex end beyond he c ea ion o a new CN. Ins ead, hey eme ge om he in e sec ion o
a ious equi emen s and demands:
•
Demands om a wide ange o economic ac o s, including indus ial companies, a e
p opelling he eme gence o new use cases.
•New echnologies o deli e ing CN componen s c ea ing mo e e icien ope a ions.
•
Changes in he equilib ium be ween business, socie al, and en i onmen al equi e-
men s o p o ide se ices in a new way.
A undamen al p inciple guiding he design o he 3GPP 5GC was no p o iding
backwa d compa ibili y wi h legacy e sions o adio access ne wo ks (RAN), i.e., GMS,
WCDMA, and LTE. This pa adigm shi , which was in ended o be as u u e-p oo as
possible, was aimed a making he 5GC agnos ic o access echnologies, enabling he
connec ion wi h any ele an access echnology as well as hose no speci ied by 3GPP.
I ins ead was designed wi h i s own se o in e aces de ined o he in e ac ion be ween
adio ne wo ks and he CN. These in e aces a e known as N2 and N3 o he signaling and
use da a pa s espec i ely. The N2/N3 we e de ined based on he S1 p o ocols de ined
by 3GPP o 4G LTE, bu wi h he in en ion o make hem as gene ic as possible, [6].
4.1.1 5G A chi ec u e
4.1.1.1 Compa ison be ween 5G SA and 5G NSA
5G Non-S andalone (5G NSA) and S andalone (5G SA) we e de ined as he wo 5G
acks ha communica ion se ice p o ide s could op o building hei 5G a chi ec u e
when ansi ioning om 4G. Unde s anding he di e en a chi ec u es was an impo an
pa o his p ojec , as elabo a ed in he ollowing sec ion.
Fi s ly, le us examine he ini ial op ion. In o de no o dis up i ely launch ea ly
5G se ices and ely on a new 5G a chi ec u e o adio and co e ne wo ks, a solu ion ha
maximizes he euse o 4G equipmen was de eloped. In p ac ice, i elies on LTE adio
access o all signaling be ween de ices and he ne wo k, and on an E ol ed Packe Co e
(EPC) ne wo k imp o ed o suppo selec ed 5G ea u es. In his case, NR is only used
o use da a, and only when he de ice is in co e age.
17
Figu e 3: Non s and-alone a chi ec u e [6].
An e iden d awback o his op ion is ha NR can only be deployed inside an LTE
co e age a ea. Addi ionally, he po en ial inno a ion ha 5G o e s is cons ained by he
capabili ies suppo ed by LTE/EPC. The p ima y dis inc ions in capabili ies lie wi hin
Ne wo k Slicing, QoS, he lexibili y o Edge Compu ing, and he gene al adap abili y
o he CN o smoo h in eg a ion wi h applica ions in an IT-like se ing. In summa y,
he e a e ou ways (8 combina ions) in which LTE and/o NR can be deployed. They a e
consolida ed in he able below:
Access Ne wo k LTE NR LTE wi h NR NR wi h LTE
EPC CN Op 1(=4G) Op 6 Op 3 (NSA) Op 8
5GC Op 5 Op 2 Op 7 Op 4
Table 2: Possible combina ions o 5G adio and co e ne wo ks.
Op ions 6 and 8 we e excluded om de elopmen due o he di ec connec ion o NR
o EPC, which would impose nume ous limi a ions on NR. A comp ehensi e desc ip ion o
hese op ions can be ound in he echnical documen 3GPP SP-160455, 2016 [7]. Howe e ,
e en i he emaining op ions we e conside ed, only op ions 3 and 2 we e comme cially
alid due o ha ing he la ges ma ke alue.
On a di e en no e, i is wo h men ioning ha op ions 2,4,5, and 7 ep esen genuine
e o s and he i s a emp o c ea e an access-independen in e ace be ween he CN
and he RAN. Op ion 3 is known o NSA, which was p e iously desc ibed, and was he
i s 5G ne wo k a chi ec u e o en e he ma ke . None heless, he o mal name o his
op ion is E-UTRAN-NR Dual Connec i i y, EN-DC.
18
Shi ing ocus back o 5G SA, his e sion is an implemen a ion o 5G ha solely
uses a 5GC, meaning i has no dependency on LTE ne wo k con ol unc ions, o signaling
and da a ans e . This in as uc u e is buil ac oss bo h he RAN and he CN, coupled
wi h cloud-na i e p inciples, such as i ualiza ion, con aine s, con aine o ches a ion,
and mic ose ices. Fo his eason, i s use o ne wo k esou ces is mo e e icien and
scalable, esul ing in an enhanced use expe ience. In 5G SA, he CN p o ides con ol
plane signaling, while he RAN handles he ans e o da a a ic be ween he inal use
and he ne wo k. The a icle published by Dhanash ee Shukla and D . Sudhi D. Sawa ka
[8] ou lines some o he di e ences be ween he SA and NSA a chi ec u es:
•
Co e age: In e ms o co e age, bo h a chi ec u es seem o be simila as hey bo h
u ilize NR co e age enhancing ea u es like Massi e MIMO o beam sweeping MIMO
o o e come high- equency ela ed issues.
•
Ne wo k Capabili y: Ne wo k slicing, lexible QoS managemen , e c. a e no
a ailable in he NSA e sion.
•
Te minal Pe o mance: In e e ence occu ences a e highe in NSA e minals due
o hei suppo o wo adio links (LTE and NR). Fu he mo e, hei pe o mance
may be a ec ed by his dual link.
•
4G/5G in e -wo king: In he case o NSA, in e -wo king is easie as he hando e
occu s in asys em, as opposed o in e sys em in he case o SA, which in oduces
highe la ency.
4.1.1.2 Concep o SBA
A signi ican depa u e om p e ious adi ional a chi ec u es, whe e nodes we e con-
nec ed by in e aces, is he u iliza ion o se ices o acili a ing in e ac ion be ween NFs.
Essen ially, his means ha NFs in e ac making accessible suppo ed unc ionali ies o
o he NFs in he ne wo k o e an API (Applica ion P og amming In e ace). Hence, o
each in e ac ion be ween NFs, one o hese ac s as a ”Se ice Consume ”, and he o he
as he ”Se ice P oduce ”.
I should be emphasized ha his communica ion applies only o c ucial signaling
se ices, no o he ans e o use da a. The e a e s ong equi emen s on eliabili y and
a ailabili y wi h lo s o so wa e in e -dependencies ha can po en ially make he sys em
b i le and agile. In complex sys ems, he e will always be cases whe e ha mless ailu es
may seem i ial and isola ed. Howe e , he possibili y o in e ac ion wi h each o he
may lead o a chao ic cascade o disas e s aking he whole sys em down. Addi ionally,
conside ing ha he SBA is a complex and igh en i y and ha many coun ies plan o
use he 5GS o eme gency se ices communica ions he possibili y o a ca as ophe a ises
[9]. The e o e, he design o he SBA is c ucial and mus be ca e ully ca ied ou .
Figu e 4 shows a i s look a he 5GC wi h Se ice-Based in e aces is shown. While
he pic u e migh sugges a comp ehensi e connec i i y mesh among all he NFs, in
p ac ice, each NF consumes speci ic se ices om o he NFs. This idea is ep esen ed
in Figu e 5 by using poin - o-poin in e aces ins ead o Se ice-Based ones. I is wo h
19
men ioning ha he pu pose o his pa o he wo k is no an exhaus i e s udy o he
in e aces and many di e en NFs, bu o unde s and how he SBA and he main NFs
wo k.
As i was p e iously s a ed, unc ionali ies o e ed by NFs a e accessible o e an
API. The communica ion me hod de ined o 5GC is based on he well-known HTTP
REST pa adigm, which is a se o ules o guidelines ha de ine how web communica ion
echnologies access se ices om dis ibu ed applica ions using APIs. These design ules
explain how o implemen he communica ion be ween di e en nodes in a ne wo ked
a chi ec u e. Da a exchange wi hin he SBA elies on JSON-encoded da a. Mos con em-
po a y p og amming languages o e a JSON module ha acili a es he con e sion om
he in e nal ep esen a ion o he ex ual JSON o ma . In [9] some o he d awbacks and
secu i y issues o using his o ma a e discussed, bu i is ou o he scope o his wo k.
Se ice-Based in e aces and APIs a e a logical choice by 3GPP, gi en ha he
so wa e applica ions esponsible o implemen ing he NFS in he 5GC a e expec ed o
ope a e wi hin an en i onmen esembling IT o sha ed IT sys ems. Figu e 4shows he
u iliza ion o he a o emen ioned HTTP REST pa adigm o se ice-based communica ion.
This is based on he de ined message syn ax om he HTTP web p o ocol and elies on
he concep o Resou ce Modeling. In p ac ice, his means ha a dis ibu ed so wa e
applica ion can be add essed h ough Uni o m Resou ce Indica o s (URIs). In addi ion,
a se o commands o s anda d HTTP ”me hods” a e being used [6]. A signi ican ace
o his pa adigm is ha REST is s a eless and does no ely on p e ious messages. This
allows o excellen scalabili y and dis ibu ion capabili ies. Nex , he mos impo an
ones a e lis ed:
•GET: used o e ching da a om a se e . I shall no change any da a.
•POST: used o send da a o a se e .
•PUT: also used o send da a o a se e , bu eplacing exis ing da a.
•DELETE: used o emo e da a om a se e
In he in oduc ion o his subsec ion, i was s a ed ha NFs ha send he eques
ha e he ole o a Se ice Consume , while he NFs ha o e hei se ice ac as
Se ice P oduce . Bu a ques ion a ises, how do Se ice Consume s keep ack o he
unc ionali ies o he Se ice P oduce s?. The answe o his ma e elies on he concep
o Se ice Disco e y. A c ucial NF, called Ne wo k Reposi o y Func ion (NRF), is
esponsible o his ask. Each Se ice P oduce egis e s ha i s se ices a e a ailable
in e ac ing wi h he NRF, which implies ha each NF needs o be con igu ed wi h a leas
one NRF, bu does no need connec ion o e e y NF in he a chi ec u e. To unde s and
his concep , a low example is desc ibed in he ollowing pa ag aphs. Fo now, he de ails
ela ed o he NFs in ol ed in he example do no ma e as hey a e explained la e in
he documen .
20
Figu e 4: 5GC isualized wi h Se ice-Based in e aces [6].
21
Figu e 5: 5GC isualized wi h poin - o-poin in e aces [6]
22
In he nex igu e, ano he NF like he AMF is in e es ed in he se ices he PCF
o e s. Hence, i que ies he NRF o a lis o PCFs ha o e he desi ed se ice. Be o e
his occu s, he PCF should ha e pu i s in o ma ion in he NRF da abase. Highligh ing
once mo e, his p ocedu e is ca ied ou using HTTP commands.
Figu e 6: PCF Se ice Regis a ion.
Figu e 7: AMF Se ice Disco e y.
A his poin , he AMF has jus ecei ed a lis o PCFs ha ul ill i s que y
equi emen s, so i needs o con ac he selec ed PCF wi h a Se ice Reques . When he
PCF ecei es he HTTP POST message om he AMF, i answe s back wi h an HTTP
RESPONSE con aining he applicable policy eques ed by he AMF. This Se ice Reques
and he p e ious s ages a e ga he ed in he nex igu e 2.
Figu e 8: AMF Se ice Reques and p e ious s ages.
2
These p ocedu es do no usually happen one a e he o he , bu when ce ain ci cums ances a e me .
23
4.1.1.3 P incipal 5GC NFs
The main unc ionali y o he ne wo k is ela ed o he ollowing asks: es ablishing
secu e sessions and o wa ding use da a o p o ide da a connec i i y. This esponsibili y
mus be in e e y 5G deploymen and he e o e, is ela ed o he ollowing NFs. Figu e 9
illus a es he co e o he 5GC.
Figu e 9: Simple 5GC e sion wi h obliga o y componen s.
Le us examine each NF one by one. Fi s ly, he AMF is he ”Access and Mobili y
Managemen Func ion”. This NF in e ac s wi h bo h he adio ne wo k and de ices
and wi h all o he NFs. I communica es wi h he adio ne wo k and de ices h ough
signaling o e he N2 and N1 in e aces, while he communica ion be ween NFs is based on
Se ice-Based in e aces. This NF is in ol ed in a majo pa o he ne wo k signaling and
allows de ice egis a ion, au hen ica ion and mo emen be ween adio cells. Howe e , his
unc ion does no pe o m he au hen ica ion o he de ice by i sel , bu a he consumes
his se ice om he AUSF.
The SMF is he ”Session Managemen Func ion” and is in cha ge o managing end-
use sessions. This includes he es ablishmen , modi ica ion, and elease o use sessions
and alloca ion o IP add esses. On he one hand, he AMF o wa ds session- ela ed
messages be ween he de ices and he SMFs. On he o he hand, i also in e ac s wi h
o he NFs by p oducing and consuming se ices. Addi ionally, i selec s and con ols
di e en UPFs o e he N4 in e ace o he con igu a ion o a ic s ee ing in he UPF
o each indi idual session. I ha was no enough, he SMF is also in cha ge o all
cha ging- ela ed unc ionali ies in he ne wo k and Policy Con ol o use sessions 3.
3
Fo his ma e i in e ac s wi h he Policy Con ol Func ion (PCF), a key NF esponsible o policy
ules ela ed o QoS, ne wo k access and use da a low.
24
4.1.1.7 NR ai in e ace
The nex igu e shows he p o ocol s ack used o he NR ai in e ace be ween he
de ices and he base s a ions.
Figu e 17: Ai in e ace p o ocol s ack.
Le us examine each laye one by one. Fi s ly, PHY is he Physical Laye , his is
he lowes laye in he p o ocol s ack. This laye is in cha ge o anspo ing o da a bi s
be ween de ices and adio base s a ions. The adio ansmission is ealized o e he adio
channels using OFDM modula ion and FDD/TDD mul iplexing schemes.
OFDM is a modula ion echnology ha is con enien o mee 5G equi emen s and
inc edibly obus agains mul ipa h ading. Basically, OFDM di ides he o al a ailable
adio spec um in o se e al subchannels, each ca ying a subca ie . The capaci ies o
each de ice a ies based on hei needs; he e o e esou ces mus be lexibly alloca ed and
can be con olled in bo h ime and equency. The equency alloca ion changes o e e y
ime slo conside ing ha he numbe o assigned subca ie s migh change depending
on he de ice. A simple e sion, wi h a educed numbe o subca ie s, o his esou ce
alloca ion concep is shown in he nex igu e.
Figu e 18: Resou ce alloca ion o h ee di e en de ices.
31
On he one hand, TDD is sho o Time-Di ision Duplex and allows he de ice and
base s a ion o sha e he same equency. In o de o a oid in e e ence, hey ansmi
da a a di e en ime slo s in a synch onized way. On he o he hand, FDD s ands o
F equency Di ision Duplex and means ha he de ice and he base s a ion use di e en
equencies o hei ansmissions. As a consequence o he egula o y si ua ion, FDD is
only suppo ed on Mid/Low bands, no on High bands.
Following he p o ocol s ack, MAC is he Medium Access Con ol Laye and is
used o he anspo o signaling in o ma ion and use da a. This laye is di ided in o
a ious logical channels, each wi h a di e en pu pose, e.g. access eques s, in o ma ion
b oadcas ing, and da a ans e s. I also p o ides suppo o mul iplexing da a om hese
logical channels in o a single PHY anspo se ice.
RLC is he Radio Link Con ol p o ocol laye . I p o ides a eliable anspo se ice
and suppo s he ansmission o signaling in o ma ion o use da a using h ee di e en
modes:
•
T anspa en Mode (TM). Only p o ides bu e ing o packe s and does no suppo
ecep ion eedback.
•
Unacknowledged Mode (UM). Wo ks in a simila way o TM, bu also suppo s
packe segmen a ion be o e ansmission.
•
Acknowledged Mode (AM). Fully suppo s ecep ion eedback and e ansmission i
needed.
On op o RLC, PDCP (Packe Da a Con e gence P o ocol) is used. Enc yp s use
da a and signaling, and p o ides op ional heade comp ession o use da a o imp o e
channel pe o mance. Addi ionally, i also eo de s packe s ha migh ha e a i ed in he
w ong o de .
A his poin , he s ack is di e en o use da a and o signaling. Radio Resou ce
Con ol (RRC) is he highes p o ocol in he s ack o ca ying signaling da a. Some o
he high-le el signaling ea u es be ween he ne wo k and de ices include b oadcas ing
o sys em in o ma ion, deli e y o enc yp ion keys, mobili y signaling, o managemen
o adio bea e s. I is also in cha ge o anspa en ly ca ying he a o emen ioned NAS
messages be ween he CN and he de ices o e he N1 in e ace.
Rega ding he use da a, Se ice Da a Adap a ion P o ocol (SDAP) is used. This
p o ocol is able o ensu e p ope QoS by mapping downlink QoS ma ked packe s owa ds
he co ec adio bea e . Addi ionally, SDAP checks he co ec QoS class ma king o
packe s ecei ed om he de ices, be o e sending hem o he UPF.
Be o e del ing in o he s udy o b oadcas ne wo ks, his wo k will p o ide a concise
o e iew o he key ea u es p esen in each i e a ion o he 5G s anda d.
32
4.1.2 Key ea u es o e e y 5G Release
In he in oduc ion o his documen , a b ie explana ion was p esen ed o elabo-
a e on ce ain ea u es in oduced in each 5G Release. The aim o his sec ion is o
u he elabo a e hose concep s and p o ide a mo e comp ehensi e unde s anding o he
undamen al p inciples.
4.1.2.1 Release 15
As i was p e iously men ioned, Phase 1, o Rel’ 15, was he i s e sion o he
new gene a ion ha was designed o co e h ee classes o use cases: enhanced Mobile
B oadBand (eMBB), massi e Machine-Type Communica ions (mMTC), and Ul a-Reliable
and Low-La ency Communica ion (URLLC). Howe e , he ini ial ocus in Rel’ 15 was
mainly on eMBB.
eMBB a ic can be conside ed o be a di ec ex ension o he 4G b oadband se ice.
I is cha ac e ized by la ge payloads and by a de ice ac i a ion pa e n ha emains s able
o e an ex ended ime. This pa e n allows he adio schedule o alloca e esou ces o
jus one eMBB de ice, in o de no o ha e wo eMBB de ices sha ing esou ces a he
same ime. eMBB se ice has o maximize da a a e while gua an eeing a ce ain eliabili y
deg ee and a minimum packe e o a e (PER) [11]. eMBB a ge s la ge-scale e en s and
igh me opoli an a eas ha ha e high da a a e equi emen s bu es ic ed bandwid h.
Some examples o hese applica ions include 4K ideo s eaming, cloud applica ions o
enhanced na iga ion [12].
4.1.2.2 Release 16
Rel’16, which commenced in ea ly 2018, mainly inco po a ed enhancemen s o he
emaining wo use cases wi hin he 5G amily: mMTC and URLLC. URLLC p o ides
eal- ime se ices o mission-c i ical scena ios equi ing a esponse ime o less han 1ms.
Some o he use cases co e ed by URLLC a e obo ic con ol-based indus ial au oma ion,
au onomous d i ing o emo e su ge y [12]. mMTC e e s o he capabili y o 5G ne wo ks
o e icien ly handle a massi e numbe o de ices. Some key poin s o his use case a e
massi e de ice connec i i y, low powe and da a a es, e icien signaling, and massi e
co e age. In summa y, mMTC is a c i ical enable o an In e ne o Things (IoT) sys em,
whe e he numbe o de ices and communica ions is inc edibly la ge.
Howe e , ela ed o he mul imedia s eaming ield he g ea es addi ion was he
deploymen o he new SDAP p o ocol. This amewo k aligned he cu en media
dis ibu ion p ac ices wi h 5G Sys ems (5GS), exposing he 5G in as uc u e o Mobile
Ne wo k Ope a o s (MNOs) s eaming se ices and hi d-pa y se ices. The goal was
o add ess he challenges ela ed o media s eaming, including he quali y o expe ience
o UEs, coping wi h inc easing quali y demands, new o ma s pe i ions, and imme si e
aspec s o he expe ience.
33
As i was p e iously men ioned, he main unc ion o his use plane p o ocol is o
es ablish a mapping be ween a QoS low and a DRB. Da a is ansmi ed on a pe -DRB
basis o e he ai in e ace, while a mo e sophis ica ed QoS low s uc u e is implemen ed
wi hin he NR CN [13]. Figu e 19 illus a es he SDAP s uc u e.
Figu e 19: SDAP p o ocol s uc u e [13].
As i can be seen in he p e ious igu e, he UE can be con igu ed wi h mul iple
SDAP en i ies, and each SDAP co esponds o a PDU session. A he same ime, a PDU
co esponds o he da a o one o mo e QoS lows. In uplink, when he UE ecei es he
SDAP SDU om he uppe laye , i ollows a mapping ule o map each QoS low o
he co esponding DRB. Then, he UE gene a es an SDAP PDU based on he ne wo k
con igu a ion and sends i o he lowe laye . Fo downlink da a, he UE unde akes
a sequence o ac ions on he SDAP PDU ecei ed om he lowe laye , ollowing he
con igu a ion p o ided by he SDAP heade be o e emo ing i . I he da a is con igu ed
wi hou a heade , i can be di ec ly sen o he uppe laye .
4.1.2.3 Release 17
Rel’ 17 b ings Mul icas -B oadcas Se ices (MBS) o he 5GS [14]. Rega ding he
equi emen s se by ei he he se ice p o ide o ne wo k ope a o s, MBS allows o
selec ion o he mos sui able among poin - o-mul ipoin (PTM) o poin - o-poin (PTP)
deli e y me hods. The con en is deli e ed om a single o igin se e o e minals ha
ha e p e iously subsc ibed o he MBS se ice.
Mul icas a ic is cha ac e ized by being e icien ly and eliably anspo ed o e
he 5GC o he compa ible gNBs. Addi ionally, hese base s a ions a e capable o deciding
whe he o use PTM o PTP me hods a he RAN based on he numbe o subsc ip ions.
I he gNB in ques ion did no suppo MBS, he indi idual a ic would be deli e ed
using unicas .
34
Figu e 20: 5G Mul icas a ic example.
B oadcas a ic is only deli e ed using he PTM me hod o anspo a ic om a
single sou ce o mul iple de ices egis e ed o he se ice wi hin a b oadcas a ea. In his
case, a single copy o he MBS a ic is anspo ed o e he 5GC o each compa ible base
s a ion.
Figu e 21: 5G B oadcas a ic example.
In conclusion, MBS Use Se ices allow popula online ele ision and adio se ices
o be deli e ed e icien ly o compa ible equipmen like sma phones, sma TVs, o ca
en e ainmen sys ems. While b oadcas is mo e sui able o localized se ices in indi idual
cells, mul icas allows a scalable deli e y o se ices while ensu ing a simila QoS and
eliabili y when compa ed o unicas ansmissions.
35
4.2 B oadcas Ne wo ks
O e he las decade, he b oadcas ne wo ks, which ha e adi ionally been he
p ima y deli e y mechanism o PTM se ices, ha e aced signi ican challenges. Fi s ly,
hese challenges a ise om egula o y and spec um issues; secondly, as a esul o he ising
compe i ion om o he ac o s wi hin he media indus y. No only ha , bu nowadays
iewe s demand highe quali y and mo e pe sonalized se ices, including he likes o OTT
se ices. Fo his eason, he indus y has ansi ioned in o an IP-based IT in as uc u e.
Signi ican endea o s ha e anspi ed o shi om adi ional DTT sys ems. In his
con ex , ATSC 3.0 eme ged as he i s IP-based DTT s anda d, o e ing a obus pa hway
o he de elopmen o a con e gen a chi ec u e wi h o he b oadband IP ne wo ks, such
as 5G. These easons and he ac ha he esea ch g oup had al eady de eloped ATSC 3.0
solu ions o di e en p ojec s we e he mo i a ions o selec ing his s anda d. The e o e,
he ocus o his pa o he s udy is se on unde s anding he ATSC 3.0 s anda d and
he echnical concep s behind hose p ojec s, in o de o inco po a e hem in o his wo k.
4.2.1 ATSC 3.0
ATSC 3.0 is a se o echnical S anda ds and Recommended P ac ices ha a e
undamen ally di e en om p edecesso sys ems. This di e en ia ion om p e ious
designs and he ac ha backwa d compa ibili y was no conside ed allows o signi ican
imp o emen s in pe o mance, unc ionali y, and e iciency. While IP anspo emains a
cen al ea u e, he s anda d has also p o ed o be able o cope wi h highe capaci y o
deli e Ul a-High-De ini ion (UHD) se ices, obus ecep ion on a wide ange o de ices,
and ad anced eme gency messaging. Addi ionally, he use o an IP s ack allows he
implemen a ion o hyb id se ices (b oadcas and b oadband) ha a e based on di e en
p o ocols like ROUTE, MMT, HTTP, o DASH.
The ATSC 3.0 s anda d is designed ollowing a laye ed a chi ec u e. As shown in he
ollowing pic u e, h ee laye s a e de ined: Physical,Managemen and P o ocols, and
Applica ion and P esen a ion. In o de o acili a e lexibili y, he di e en elemen s
ha encompass his sys em a e speci ied in sepa a e s anda ds.
Figu e 22: ATSC 3.0 laye ed s uc u e.
Each ATSC 3.0 s anda d is designed in a lexible way so i can accommoda e u u e
adap a ions. In some cases, pa allel op ions a e speci ied o ce ain ope a ions, om
which b oadcas e s can choose which me hod is mo e sui able o each p ojec . Figu e 23
36
is an illus a ion ga he ing he a ious documen s ha oge he comp ise he s anda d
and he opics o which hey belong.
Figu e 23: ATSC 3.0 documen s s uc u e.
4.2.1.1 Se ice Deli e y
Following he A/331 ”Signaling, Deli e y, Synch oniza ion and E o P o ec ion” s an-
da d [15], wo me hods o B oadcas Se ice deli e y a e speci ied in he s anda d. The
me hod on he le side o Figu e 2, is based on MPEG Media T anspo (MMT) and
uses MMT P o ocol (MMTP) o deli e Media P ocessing Uni s (MPUs). This p ojec
cen e s i s a en ion on he me hod depic ed in he cen e o Figu e 2, which is oo ed in
he DASH-IF p o ile—a amewo k buil upon he ounda ion o MPEG DASH. I uses
Real-Time Objec Deli e y o e Unidi ec ional T anspo (ROUTE) p o ocol o deli e
DASH segmen s. Fo he deli e y o hyb id se ice on he b oadband side, DASH-IF
u ilizes he HTTP/TCP/IP s ack.
ATSC 3.0 se ices a e deli e ed using h ee unc ional laye s: The physical Laye ,
he Deli e y Laye , and he Se ice Managemen Laye . The Physical Laye acili a es
he anspo a ion o signaling, se ice announcemen and IP packe s eams o e he
B oadcas Physical Laye and/o B oadband Physical Laye . The Deli e y Laye is
esponsible o he anspo a ion unc ionali y o objec s and objec lows. This laye
is enabled by he ROUTE p o ocol, ope a ing on op o a UDP/IP mul icas s ack o e
37
he B oadcas Physical Laye , and enabled by he HTTP p o ocol on a TCP/IP unicas
o e he B oadband Physical Laye . The main ole o he Se ice Managemen laye is
o acili a e he disco e y and acquisi ion o a ious ypes o se ices, like linea TV o
HTML5 applica ions. These se ices a e ca ied by he unde lying Deli e y and Physical
laye s. Figu e 24 shows he ATSC 3.0 ecei e p o ocol s ack 4.
Figu e 24: ATSC 3.0 ecei e p o ocol s ack.
Le us del e deepe in o he unde lying concep s o his a chi ec u e. Se ice Signaling
p o ides se ice disco e y and desc ip ion in o ma ion, and consis s o wo unc ional
elemen s: Boo s ap Signaling ia he Se ice Lis Table (SLT) and Se ice Laye
Signaling (SLS).
Fo a ecei e ha is encoun e ing he b oadcas o he i s ime, he SLT is he
place o s a . The SLT acili a es a quick channel scan, enabling he ecei e o compile a
lis o all a ailable se ices, wi h hei name, channel numbe and mo e. Addi ionally, he
SLT o e s boo s ap in o ma ion ha aids he ecei e in iden i ying he SLS o each
se ice. In he case o ROUTE/DASH se ices, he boo s ap in o ma ion p o ides a
sou ce IP add ess, des ina ion IP add ess, and he des ina ion po o he LCT channel
ha ca ies he ROUTE-speci ic SLS.
In he con ex o se ice deli e y ia ROUTE, he SLS o each se ice desc ibes
cha ac e is ics o he se ice, such as a lis o i s componen s and how o access hem,
as well as he ecei e capabili ies necessa y o a meaning ul p esen a ion o he se ice.
Using dis inc se ice signaling o each se ice allows a ecei e o ob ain he desi ed
SLS o a pa icula se ice wi hou analyzing he en i e SLS ca ied wi hin a B oadcas
S eam. Rega ding ROUTE/DASH b oadcas se ices, he SLS is con eyed ei he using a
Signaling Se e o h ough ROUTE/UDP/IP wi hin one o he LCT (Laye ed Coding
T anspo ) anspo channels o ming a ROUTE session. The nex igu e shows he
ela ionship o hese logical en i ies in a UML diag am.
E e y ROUTE session consis s o one o mo e LCT channels ha collec i ely o
pa ially anspo he componen s o ming he ATSC 3.0 se ice. Fo s eaming se ice
4
No e ha he MMTP pa o his s ack is illus a ed wi h educed anspa ency as i is no u ilized
in his p ojec .
38
Figu e 25: UML Diag am.
deli e y, an LCT channel migh ca y an indi idual componen o a use se ice, such as
audio, ideo, o closed cap ion. S eaming media is o ganized in o DASH Segmen s.
A B oadcas S eam is a concep ual ep esen a ion o an RF channel, cha ac e ized
by a ca ie equency si ua ed wi hin a designa ed bandwid h. I is uniquely iden i ied
by i s [geog aphic a ea, equency] pai . A Physical Laye Pipe (PLP) co esponds o a
segmen o he RF channel. Each PLP is associa ed wi h speci ic modula ion and coding
pa ame e s. In a B oadcas S eam, he e a e a ce ain numbe o ”g oups”. I e e s
o an abs ac ion o ”b oadcas e ” o s a ion and each se ice in a B oadcas S eam is
associa ed wi h a single g oup alue (LLS g oup id). This concep allows mul iple s a ions
o ope a e on a single RF channel wi h a ce ain deg ee o independence.
Signaling in o ma ion ca ied in he payload o IP packe s wi h a well-known ad-
d ess/po dedica ed o his endea o is e e ed o as Low Le el Signaling (LLS). The
SLT i sel , which has been discussed ea lie , se es as an example o LLS in o ma ion, in
he o m o an LLS Table. These packe s shall be ansmi ed using he 224.0.23.60 IP
add ess and he 4937 UDP po . All IP packe s, excep o LLS IP packe s, shall ca y a
unique and ese ed Des ina ion IP add ess alloca ed by a mechanism o in he ange o
239.255.0.0 - 239.255.255.255. SLTs mus be ansmi ed wi hin hei LLS e e y 5 seconds
bu can be epea ed mo e equen ly, ideally e e y second, o speed up ecei e channel
scanning.
In conclusion o he se ice deli e y sec ion, i is no ewo hy o men ion ha SLS
signaling suppo s he deli e y o se ice componen s in mul iple PLPs. Fo example, a
se ice could be con igu ed o ca y ideo in one PLP and audio in a di e en , mo e obus ,
PLP. Rega ding some limi a ions in ce ain ecei e s, componen s o any gi en se ice
should be con eyed h ough a maximum o ou ALP packe s eams, which includes he
ALP s eam ca ying he LLS ables ha desc ibe ha pa icula se ice.
The igu e below
5
demons a es how a obus audio se ice is s uc u ed using one
PLP/ALP s eam o each ROUTE session. This se ice employs wo di e en Quali y o
Se ice (QoS) le els. The i s , which is mo e esilien , handles bo h signaling and audio
5
Each LCT channel is dis inguished by a T anspo Session Iden i ie (TSI), and his iden i ie is
unique wi hin he con ex o he pa en ROUTE session.
39
wi hin a single ROUTE session. The second QoS, which is less obus , is esponsible o
deli e ing ideo and ex , like closed-cap ioning, in a sepa a e ROUTE session.
Figu e 26: Example o sepa a e ROUTE sessions/PLPs o di e en ia e QoS o ideo and
audio.
4.3 Con e gence be ween B oadcas and B oadband sys ems
A e s udying bo h sys ems and hei espec i e s anda ds, he inal endea o is o
comp ehend he ini ia i es aimed a achie ing ha moniza ion and con e gence be ween
hese wo a chi ec u es. The e e ences compiled in [16] p o ide a g ea s a ing poin o
highligh he bene i s o con e gence and o lis he con ibu ions in his ield.
As p e iously men ioned, he ully-IP-complian design o ATSC 3.0 acili a es
con e gence be ween B oadcas and B oadband in a ious sys em laye s, no limi ed o
jus he applica ion/p esen a ion laye . This implies ha a ic o loading and owe
sha ing a e easible h ough he con e gence a he anspo a ion and physical laye s,
espec i ely.
One o he key ea u es o he media and en e ainmen indus ies is use in e ac-
i i y. The mos ou s anding example o in e ac i i y in B oadband media se ices is a
cus omized con en dis ibu ion model, e e ed o as na owcas ing. None heless, in he
e a o con e gence, media b oadcas ing will h i e h ough in e ac ions be ween di e en
pla o ms and sys ems, placing g ea e emphasis on his kind o in e ac i i y a he han
use -in e ac i i y. Addi ional con e gence bene i s can be discussed as ollows:
•
Enhanced Quali y. Deli e ing 4K/8K UHD ideo, high-dynamic ange (HDR),
o wide colo gamu (WCG) is possible wi h a mul i-connec i i y scheme ha
40
Se s and o he pa ame e s like he a ailabili y s a ime o maximum segmen du a ion.
This in o ma ion is used o c ea e he SLS wi hin he T ansmi sec ion. Addi ionally, i
can be seen some ROUTE session- ela ed pa ame e s like he mul icas add ess:po pai ,
o he LCT channel, a e all encapsula ed wi hin he S-TSID.
Fo he ansmi e componen , he DekTec DTU-315 modula o is employed. This
USB modula o is a po able de ice capable o ope a ing om VHF o L band (36 MHz
- 2150 MHz). I suppo s all cons ella ions and modula ion modes o each suppo ed
s anda d while deli e ing excellen signal quali y o he RF ou pu signal. In conclusion,
i aligns pe ec ly wi h he p ojec ’s equi emen s as i is compa ible wi h ATSC 3.0, in
addi ion o i s ou s anding RF cha ac e is ics.
Figu e 30: DekTec DTU-315 Modula o .
Fo he ecei e componen , he DekTec DTA-2131 is employed. Unlike he DTU-315
modula o , his ecei e u ilizes a PCIe in e ace ins ead o USB 3.0. I is also complian
wi h ATSC 3.0 s anda ds and op imized o in eg a ion wi h So wa e De ined Radio
(SDR) echnology. Consequen ly, i has he capabili y o o wa d ATSC 3.0 packe s o IP.
Fu he mo e, his p oduc is bundled wi h he A sc3Xpe so wa e, o e ing ad anced RF
measu emen s, decoding o all signaling in o ma ion, and ea u es such as he eco ding o
PLP da a in PCAP iles, as well as eal- ime ALP and ROUTE/MMT ou pu o e IP.
Figu e 31: DekTec DTA-2131 Recei e .
47
Figu e 32: T i eni GuideBuilde MPD Injes .
Figu e 33: T i eni GuideBuilde ROUTE T ansmi .
48
5.4
Phase 4: Design and Implemen a ion o a Con e gen A -
chi ec u e be ween ATSC and 5G
Once he pe o mance o bo h p o o ypes has been sepa a ely es ed, he design
and implemen a ion o a con e gen a chi ec u e shall begin. Howe e , an impo an
ques ion has o be add essed i s : whe e in he p o ocol s ack should he p ojec ocus on
implemen ing con e gence?
Re ospec i ely e iewing he S a e o he A , i is e iden ha he mos in e es ing
ype o con e gence ha sui s he p ojec esides a IP le el. The e o e, he e o s o his
phase should be ocused on de eloping his concep . The con e gence case explo ed in
his p ojec is ela ed o p o iding ideo s eaming se ice o he end use in such a way
ha e en in he p esence o ailu es in he b oadband ne wo k, he same se ice con inues
o be deli e ed h ough he DTT ne wo k.
Once again, as men ioned in he p e ious phase, he echnical de ails o he inal
p o o ype’s ope a ion will be elucida ed in he co esponding sec ion. Howe e , le us ake
a close look a wha needs o be de eloped in his phase. The 5GC shall conduc a bi a e
analysis o he end use de ice and, based on he esul s, p epa e he DTT ansmi e
o b oadcas he ideo when he necessi ies o ha pa icula se ice a e no me . The
end use should emain unawa e o his p ocess. Howe e , gi en he p ojec ’s scope, i is
no easible o de elop a op-laye applica ion ha handles hese p ocedu es and plays
he ideo ega dless o he ne wo k o which i is connec ed, as ha would equi e a e y
p ecise synch oniza ion scheme be ween bo h ne wo ks. Fo his eason, his p ojec aims
a o e ing he se ice unde he a o emen ioned condi ions bu being ully awa e ha a
sepa a e applica ion is equi ed o play he ideo (e.g., VLC, S eamXpe , o an ATSC
3.0 complian ecei e connec ed o a TV).
Rega ding he analysis pe o med by he 5GC, an in e ac i e Py hon web applica ion
has been deployed on he CN o moni o he ac i i y o he b oadband ne wo k. Fu he -
mo e, i s in e ac i i y enables a ious ac ions o be pe o med di ec ly on he ne wo k,
such as in oducing delay, changing he maximum a ailable link bi a e, o adjus ing he
packe loss pe cen age. I also enables emo e in e ac ion wi h he ATSC 3.0 ne wo k,
achie ing a ce ain le el o coope a ion be ween bo h ne wo ks. This ha moniza ion allows
he emo e con ol o he DTT ansmi e di ec ly om he 5GC. The so wa e ep esen s
he pinnacle o his wo k and will assis in u u e esea ch p ojec s as i se s a p eceden
in he con ex o in e ac ion be ween 5G and DTT ne wo ks.
5.5 Phase 5: Simula ion and analysis o con e gen use cases
The con e gen a chi ec u e is employed in he inal phase o es and analyze
con e gen use cases. One o he p ima y objec i es o hese simula ions is o empi ically
de e mine, based on ne wo k condi ions, he op imal igge poin o swi ching o he
ATSC ne wo k. Du ing s ess es s ela ed o hese use cases, he ne wo k exhibi s pa e ns
ha could e en ually acili a e au oma ed de ec ion o subop imal se ice deli e y in he
b oadband ne wo k. Howe e , a his ime, his de e mina ion, which di ec ly impac s
end-use QoE, emains non-au oma ed and equi es a se ies o manual es s.
49
Fo his phase, he ollowing use cases ha e been analyzed:
•
E ec o mobili y in he cell on mul imedia s eaming. Inc easing he
dis ance be ween he base s a ion and he end use esul s in a bi a e educ ion,
subsequen ly impac ing he s eaming se ice. As a use p og essi ely mo es away
om he base s a ion, se e al ac o s ha a ec he connec ion quali y and da a
ans e speed may come in o play, such as signal a enua ion, modula ion scheme
changes, o esou ce ealloca ion. Ul ima ely, he dis ance be ween he use and
he base s a ion can signi ican ly in luence he bi a e due o hese e ec s. Fo he
simula ion in his sec ion, he maximum bi a e o he mobile ne wo k is g adually
educed o analyze he bi a e pa e n and he applica ion (VLC) beha io unde
hese condi ions. This allows o he de e mina ion o when o swi ch o he DTT
ne wo k.
•
E ec o delay on mul imedia s eaming. Inc easing delay and i s a ia ion,
also known as ji e , esul s in a se ies o e ec s and impac s on he s eaming se ice.
Delay e e s o he ime i akes o in o ma ion o a el om he s eaming se e
o he sma phone. I can occu a di e en poin s in he ne wo k and may be
in luenced by ac o s such as p opaga ion ime h ough a physical medium o he
p ocessing ime equi ed o ansmi bi s o e a link. On he o he hand, ji e e e s
o he a ia ion in delay expe ienced by da a packe s. They may encoun e di e en
delays e en when sen a di e en ime in e als. Addi ionally, a ic luc ua ions
con ibu e o hese a ia ions. In essence, bo h delay and ji e impac he ne wo k
and, consequen ly, he s eaming se ice. In simula ion es s, he bi a e has been
p og essi ely inc eased un il eaching a ixed poin . Once ha ixed poin was
eached, he ji e was modi ied, esul ing in a di e en ne wo k beha io .
50
6 A chi ec u es o 5GS and E alua ion P ocedu e
This sec ion aims o explain he a chi ec u e o s udying he DASH da a deli e y
o e a 5G sys em, ocusing on some key aspec s o he solu ion, such as he designed
a chi ec u es o he logging ool.
6.1 A App oach
This p o o ype ep esen s a signi ican con ibu ion o he hos ing esea ch g oup
as i enables he deploymen o a p i a e 5G ne wo k in he labo a o y o es ing and
de eloping di e en esea ch p ojec s, no limi ed o his s eaming se ice. The a ailabili y
o a 5G es bed o conduc ing di e se expe imen s pa es he way o a ious esea ch
p ojec s o in e es . This being said, le us begin wi h he explana ion.
The p ima y objec i e is o ensu e he co ec ope a ion o he sys em, ensu ing
ha end use s ecei e he ideo s eaming se ice as in ended. The e o e, he i s s ep is
o design he a chi ec u e, keeping in mind ha he DASH mul imedia se e should be
accessible om he 5GC and, hus, o he use s wi hin he 5G ne wo k. As was p e iously
men ioned in 5.2, in he i s app oach, his p o o ype was mean o wo k wi h jus a
sma phone connec ed o he 5G ne wo k. Fig. 34 illus a es he ini ial a chi ec u e
design7.
Figu e 34: Ini ial 5G a chi ec u e design.
Howe e , his design was limi ed by he ha dwa e a ailable a ha s age. The main
p oblem was ha he sma phone in ended o ecei e he s eaming se ice could no
connec o he 5G ne wo k. To add ess his issue, di e en al e na i es we e conside ed.
6.1.1 T oubleshoo ing
Fi s , i was con empla ed ha some incompa ibili ies be ween adio echnology
and he sma phone could exis . The e o e, pa ame e s like he equency band o he
powe /gain we e e alua ed and modi ied acco dingly. None heless, he use e minal
and he 5GS ope a ed in he n78 NR band a 3489 MHz. Addi ionally, conside ing he
Ama i Callbox use manual, he signal powe le el indica ed ha he powe and gain we e
app op ia e o co ec signal ecep ion.
7The IP add ess o he UE is alloca ed by he AMF in he 5GC.
51
The nex s ep was o conside he possibili y o issues wi hin he 5GC. In his con ex ,
he logging ool Ama iso p o ided was help ul. I s web use in e ace allows o examining
message exchanges wi hin he NR ai in e ace and he NAS message in e ac ions among
he 5GC en i ies. While Figu e 35 illus a es a pa o a success ul example o a 5G SA
ne wo k connec ion om he UE, Figu e 36 shows he IP add ess alloca ion in he PDU
Session Es ablishmen Accep message. This message, which is ypically sen by he AMF
o he UE, is pa o he 5G session managemen p ocedu es and is used o con i m he
es ablishmen o a PDU session o da a communica ion be ween he UE and he 5GC. I
con ains impo an in o ma ion like he alloca ed IP add ess and IP 4 (IP 6 i suppo ed)
DNS Se e add ess.
Figu e 35: 5G SA Success ul Regis a ion P ocess.
52
Figu e 36: PDU Session Es ablishmen Accep message and alloca ed IP add esses.
So, using his ool makes i possible o check he p ocess behind he ne wo k
connec ion a emp om he UE.
1.
RACH P ocess. RACH s ands o Random Access Channel and is essen ial o
wi eless communica ion sys ems, no limi ed o 5G. I plays a signi ican ole in
es ablishing an ini ial connec ion be ween he UE and he ne wo k. In his con ex ,
i is u ilized by a UE o acqui e uplink synch oniza ion and o ob ain he speci ied
ID o he adio access communica ion.
2.
RRC Se up Reques . When he RACH p ocess is comple e, he UE gene a es
an RRC Se up Reques message, which includes essen ial in o ma ion such as i s
iden i y, capabili ies, and eques ed se ices. I is ansmi ed o he gNB, which
hen p ocesses he eques o au hen ica e he use and de e mine he app op ia e
adio esou ces.
3.
[NAS] UL 5GMM: Au hen ica ion Response. I he au hen ica ion p ocess
was success ul on he UE side, his message should be on he message in e change
g aph. A usual ailu e in his p ocess implies ha he e is a SIM pa ame e misma ch
be ween he USIM and gNB pa ame e s.
4. A e his secu i y con ol, he ollowing messages should appea :
53
•[NAS] UL 5GMM: Secu i y mode comple e. NAS Secu i y is comple e.
•
UL DCCH-NR: Secu i y mode comple e. This shows ha RRC Secu i y
is comple e.
•
UL DCCH-NR: RRC Recon igu a ion comple e. This message implies
ha RRC Recon igu a ion is comple e and he physical pipe o communica ion
is se up.
•
[NAS] UL 5GMM: Regis a ion comple e. This shows ha he ini ial
a ach p ocess is comple e.
5.
Finally, he PDU Session es ablishmen Reques /Response message. As
men ioned ea lie , his message is used, among o he hings, o alloca e an IP add ess
o he UE and p o ide i wi h a lis o DNS se e s. Howe e , a his poin , he
de ice ails o connec wi h he In e ne o he UPV/EHU ne wo k as i is no
assigned any IP add ess. While i success ully accessed IMS se ices, i could no
access any o he IP ne wo k, ende ing i p ac ically unusable o his p ojec . Hence,
ano he design was p oposed as a solu ion.
.
6.2 B App oach
The second design p oposal shi ed he end-use componen o he a chi ec u e
om a sma phone o a 5G ou e wi h known compa ibili y and pe o mance on 5G
SA ne wo ks. This pa adigm shi opened up new possibili ies o he p ojec , enabling
he use o compu e s as end de ices. As a esul , i allowed o he deploymen o mo e
ambi ious p og ams, as he ha dwa e limi a ions o sma phones we e no longe a conce n.
The 5G ou e expands he 5G se ice o bo h WiFi and E he ne connec ions, making
i possible o connec a wide ange o de ices o he 5G ne wo k. The ollowing pic u e
illus a es he inal ully unc ional a chi ec u e design. Wi h his inal se up, use s o he
WiFi/E he ne ne wo k a e able o ecei e he s eaming con en ia 5G seamlessly.
Figu e 37: Final 5G a chi ec u e design.
54
6.2.1 T oubleshoo ing
Un o una ely, jus days p io o he scheduled lab es s, a mal unc ion was encoun-
e ed wi h he 5G ou e . This necessi a ed he p omp esolu ion o he issue and he
explo a ion o al e na i e solu ions. Gi en he ime cons ain s, c ea ing an en i ely new
ne wo k a chi ec u e was deemed imp ac ical, leading o he decision o e e o he
ini ial design.
Tho ough conside a ion had p e iously been gi en o a ious ac o s pe aining
o adio issues, and an exhaus i e e alua ion con i med he co ec ness o he 5GC
con igu a ion, as e idenced by he success ul connec ion o he ou e o he ne wo k.
Consequen ly, a en ion was di ec ed owa ds he ne wo k con igu a ion o he sma phone.
Upon in es iga ion, i was de e mined ha he issue s emmed om an e oneous
au o-con igu a ion o he Access Poin Name (APN) on he sma phone. A manual
adjus men o he APN se ings was unde aken o ec i y he p oblem. The ollowing
igu e depic s he co ec APN con igu a ion, highligh ing he impo an in o ma ion
(Name, APN, and APN Type).
Figu e 38: APN Con igu a ion.
55
The de aul con igu a ion success ully connec ed o one o he a ailable APNs in
he 5GC, assigning he use he IP add ess 192.168.3.2 om he a ailable ange. This
enabled seamless access o mul imedia s eaming se ices wi hin he 5G ne wo k. Bo h
a chi ec u al designs ha e hei own ad an ages and d awbacks, as depic ed in he able
below. To add ess he issue o equi ing wo end-use de ices o a ou e in be ween,
he Quec el 5G-M2 EVB Ki was sugges ed as an ideal solu ion. This de elopmen ki
allows o he managemen o a b oade ange o 5G- ela ed pa ame e s compa ed o
a comme cial de ice like a sma phone. Fu he mo e, i is con olled om a compu e ,
elimina ing he need o wo end-use de ices. Howe e , his op ion has been ese ed o
u u e wo k due o he p ojec ’s scope.
Table 3: Ad an ages o using a sma phone o a 5G ou e .
Figu e 39: Quec el 5G-M2 EVB Ki .
56
8
A chi ec u es o a Con e gen Sys em and E alu-
a ion P ocedu e
This inal echnical sec ion o he documen aims o p o ide a comp ehensi e ex-
plana ion o he con e gen p o o ype. A e s udying he wo p eceding p o o ypes
independen ly, i is easie o unde s and he idea behind he inal a chi ec u e. The
p ima y objec i e o his design is he in eg a ion o bo h sys ems, wi h he 5GC assuming
he ole o he cen al en i y esponsible o bo h Radio Access Ne wo ks (RAN). Thus,
g an ing access o s eaming se ices o he use s wi hin he 5G ne wo k and es ablishing
connec ions wi h he ATSC ne wo k. In his con ex , he ansmi e can be managed
o align con en wi h me ics p o ided by he 5GC. Fu he mo e, he con igu a ion o
he ecei e enables he selec ion o he RANs om which con en will be ecei ed. The
ollowing igu e illus a es he inal design.
Figu e 47: Final con e gen a chi ec u e design.
Two DASH se e s a e depic ed in he uppe -le sec ion o he igu e abo e. One o
hese se e s is linked o he EHU/UPV ne wo k o acili a e communica ion wi h he 5GC.
In con as , he o he de ice is connec ed o a p i a e LAN. This a angemen is due o he
ac ha he T i eni Guidebuilde is hos ed on a Vi ual Machine ha is in e connec ed
wi h his speci ic p i a e LAN and can no ha e di ec access o he public in e ne . The
5G sys em is illus a ed in he igu e’s uppe - igh sec ion. In his e sion, h ee o ange
ba s ha e been added o signi y he analysis and moni o ing o he bi a e in bo h he
mobile b oadband and he b oadcas ne wo ks. Some pu ple lines ha e also been added o
isualize he con e gen communica ion be ween he 5GC and he ansmi e and ecei e
modules o he DTT ne wo k. The DTT ansmi e also uses his communica ion line o
send he measu ed bi a e alues o he 5GC.
63
8.1 KPI p ocessing
Le us del e deepe in o he analysis and moni o ing pa o he a chi ec u e. Fi s ly,
he bi a e analysis in he 5G ne wo k en ails a se ies o ac ions. The Ama iso so wa e
p o ides logs con aining speci ic in o ma ion abou he communica ion be ween he base
s a ion and he use e minal, such as bi a e, MCS (Modula ion and Coding Scheme),
and SNR (signal- o-noise a io), among o he s. This se o pa ame e s p o es highly
aluable when conduc ing a mobile communica ion analysis. Howe e , only he uplink
and downlink bi a es a e u ilized o his ini ial con e gen p o o ype de eloped wi hin
he p ojec . The ollowing igu e p o ides an example o he logs men ioned.
Figu e 48: Ama iso log example.
Reg e ably, di ec plo ing o his log in o ma ion is no easible, necessi a ing he
implemen a ion o addi ional p ocessing s eps. This p ocedu e is an in eg al pa o he
so wa e de eloped o his p ojec and encompasses he ollowing aspec s:
•
P ocessing he log iles o gene a e pai s o imes amps and bi a es. The inclusion
o a ime axis enhances he cla i y o he esul p esen a ion. The ollowing sc ip
u ilizes he awk command o manipula e he sc eenlog ou pu and hen lush he
esul in o a inal ile.
#!/bin/sh
ail − sc eenlog.1 |awk '{p in s ime("%H:%M:%S"),$0; ...
lush();}'| ee SCREEN. x
Figu e 49: P ocessed Ama iso log example.
64
•
Once he log ile is p ocessed, i is possible o emo e all heade s and ex aneous
in o ma ion ha a e i ele an o his p ojec , such as UE-ID, CL, RNTI, o —-DL—-
heade s. The ollowing Py hon code eads he p ocessed ile and appends he desi ed
lines o an a ay p ocessed in he nex s ep.
de ge lines():
## P ocess he ile and e u ns a ay o lines wi h jus numbe s.
## Skips lines con aining "DL" o "UE−ID".
y:
wi h open("SCREEN. x ",' ')as ile:
a ay = []
lines = ile. eadlines()
o line in lines:
i no "DL" in line:
i no "UE ID" in line:
i no "PRACH" in line:
i no "[s opped]" in line:
a ay.append(line)
e u n a ay
excep FileNo FoundE o :
p in ("File no ound.")
excep IOE o :
p in ("E o eading he ile.")
•
A his poin , he a ay con ains only he essen ial in o ma ion. Among all he
pa ame e s in he log, his p ojec ocuses solely on bi a e alues. The e o e, he
ollowing unc ions e u n hose alues and pe o m a ype cas ing in o nume ical
alues o hei ep esen a ion.
de ge bi a e(lines,ch=None):
## Ge s he p ocessed lines as an inpu and e u ns jus he ...
bi a e alue.
## I i possible o selec DL o UL o bi a e alues.
spli = []
da e = []
bi a e = []
o iin lines:
spli .append(s .spli (i))
i ch == "DL":
o iin spli :
da e.append(i[0])
bi a e.append(i[10])
i ch == "UL":
o iin spli :
da e.append(i[0])
bi a e.append(i[18])
e u n bi a e,da e
65
de p oc nume ic(bi a e):
## P ocesses he alues so i changes kilo in o base uni , mega ...
in o base uni ...
p ocessed = []
o alue in bi a e:
i alue[−1] == 'k':
num = ound( loa ( alue[:−1]),2)
eli alue[−1] == 'M':
num = ound( loa ( alue[:−1]) *1000,2)
else:
num = loa ( alue) / 1000
p ocessed.append(num)
e u n p ocessed
•
Finally, a e he p eceding s eps, he alues can be ep esen ed in a cha . To
achie e his, he ollowing code has been u ilized.
de load cha (wid h, heigh , p ocessed, use colou , imeS ings, ...
slide ):
# C ea e a Da aF ame wi h he index as da e ime objec s
ime objec s = pd. o da e ime( imeS ings, o ma ="%H:%M:%S")
da a = pd.Da aF ame({'Bi a e (kbps)': p ocessed},...
index= ime objec s)
line cha = al .Cha (da a. ese index()).ma k line(
colo =use colou ,
s okeWid h=slide ,
).encode(
x=al .X('index:T', i le='Time',...
axis=al .Axis( o ma ="%M:%S",g id=T ue)),
y=al .Y('Bi a e (kbps):Q', i le='Bi a e (kbps)'),
).p ope ies(
wid h=wid h,
heigh =heigh
)
e u n line cha
9 Resul s and Discussions
The p e ious p ocedu e enables analyzing and moni o ing 5G uplink and downlink
bi a es. This p ocess iden i ies when he s eaming se ice is a ec ed by ne wo k- ela ed
p oblems. I is concei able ha hese issues may lead o a bi a e educ ion, di ec ly
impac ing he se ice and QoE.
The de eloped so wa e analyzes he cell’s bi a e and ac s acco dingly when speci ic
condi ions a e me . Howe e , hese condi ions a y depending on he ideo eques ed by
he use . In his p ojec , he use eques ed a ideo sample wi h a mean bi a e alue
o app oxima ely 2.8 Mbps. This es was conduc ed u ilizing he second a chi ec u e
model o 5G (Fig. 37), and he measu ed alues se ed as a h eshold o de e mine
66
when he se ice may encoun e issues. The igu e below illus a es he bi a e alues
ob ained du ing a 1.5-minu e analysis o his ideo, es ablishing he h eshold. Ac ually,
conside ing ha his is he mean alue o ha lis , i would be a be e choice o employ
a sligh ly lowe h eshold. Consequen ly, i bi a e alues emain below ha h eshold o
a ce ain pe iod ( his allows o igno e ne wo k spikes), i would be possible o de e mine
ha he se ice is being di ec ly a ec ed.
Figu e 50: DL bi a e alues o he sample ideo.
Howe e , as p e iously men ioned, he 5G ou e s a ed mal unc ioning, and he
sma phone had o be used ins ead. While he ob ained esul s p o ed o be help ul,
in o de o de e mine he ATSC Swi ching Poin mo e accu a ely, addi ional es s we e
ca ied ou o analyze he beha io o he ne wo k unde speci ic condi ions. These
condi ions a e di ec ly ela ed o he use cases explained in he Me hodology (see 5.5).
9.1 UE Mobili y and QoE deg ada ion
Mobili y, and mo e p ecisely, an inc easing dis ance be ween he base s a ion and
he end-use , di ec ly impac s he bi a e. As a use mo es u he away om he base
s a ion, a ious ac o s ha in luence he quali y o he connec ion and he speed o da a
ans e may a ise. These ac o s a ec he QoE o he eques ed s eaming se ice and
a e a ypical p oblem in he edges o he co e age a eas.
In his es , his beha io is modeled by analyzing he impac o g adually limi ing he
maximum bi a e ha he 5G link can o e . We a e ying o emula e a CQI deg ada ion.
The ollowing sc ip is execu ed a egula in e als, app oxima ely e e y 30 seconds, o
e alua e he applica ion’s pe o mance on he use e minal o accomplish his objec i e.
Du ing he ini ial execu ion o he sc ip , he add op ion mus be u ilized, ollowed by he
desi ed maximum bi a e. Subsequen es s will employ he change op ion, again ollowed
by he desi ed bi a e.
67
#!/bin/bash
i [[ "$1" == 'add' ]]
hen
c qdisc add de un1 oo handle 1:0 h b de aul 1
c class add de un1 pa en 1:0 classid 1:1 h b a e "$2"kbi
eli [[ "$1" == 'change' ]]
hen
echo You changed he bi a e o "$2" kbi s
c class change de un1 pa en 1:0 classid 1:1 h b a e ...
"$2"kbi
i
The i s es s aimed o de e mine he ATSC Swi ching Poin , so hese esul s do no
show any ATSC 3.0 bi a e ye . The s a ing poin was se a 3000 Kbps and g adually
educed un il 2400 Kbps we e eached. I is wo h men ioning ha he s opping poin o
he bi a e educ ion is p oduced because he applica ion s a s mal unc ioning and some
ideo a i ac s s a o appea , a ound 2500 - 2400 Kbps. These a i ac s a e isual e o s
ha a ec he ideo. In some cases, hey a e ela ed o ideo s alling, which is he case
s udy o his p ojec , and in o he cases, hey a e ela ed o blu y ames. The ollowing
esul s a e p omising and will pa e he way o p ecisely de e mining he swi ching poin ,
besides acknowledging di e en ne wo k and applica ion beha io s.
Figu e 51: Bi a e downg ade Tes I.
68
Figu e 52: Bi a e downg ade Tes II.
F om he p eceding igu es, a subs an ial amoun o in o ma ion can be de i ed.
Rega ding he i s es (Fig 51), wo comple ely di e en app oaches can be seen. Du ing
he ”no bi a e limi a ion” pe iod, he de ice had no limi a ion in eques ing ideo
segmen s. Hence, wi hou limi a ions, he applica ion ope a ed a high pe o mance, illing
he bu e and eques ing la ge quan i ies o bi s. This is why g ea a ia ion in bi a e
can be obse ed du ing his pe iod.
On he con a y, he beha io is o ally di e en when he a ailable bi a e is limi ed.
Unde hese condi ions, he applica ion could no longe eques such high bi a es and
ied o e icien ly manage he bu e and play he con en seamlessly. Thus, he bi a e
a ia ion is di ec ly limi ed o he bi a e limi . Aside om he bi a e beha io , his
es p o ided a i s concep o he ela ionship be ween he bu e managemen and he
a i ac s. I is possible o see ha when he bi a e emained unde ce ain alues (a ound
2500 Kbps) o a pe iod o ime, he a i ac s s a ed o happen. The e o e, i can be
de e mined ha when he bi a e alls below he h eshold alue o a ce ain du a ion,
a ious beha io s o he applica ion lead o a common ou come: a i ac s. In his case,
he applica ion ied o play he con en while bu e ing, esul ing in wo s alling momen s
which a e depic ed abo e. VLC shows a o a ing cone in he applica ion du ing hese
momen s.
Figu e 53: VLC S alling.
69
Fig 52 shows a e y simila beha io , esul ing in h ee a i ac s du ing his es .
Bo h esul s allow he de e mina ion o a h eshold o app oxima ely 2500 Kbps o he
ATSC Swi ching Poin o his use case. Unde s anding he swi ching poin enables
he execu ion o he inal con e gence es s, as i becomes easible o pe o m ne wo k
ansi ions when he 5G ne wo k mee s hese condi ions. The esul s ob ained du ing
hese con e gence es s a e depic ed below.
Figu e 54: Use Case Analysis - Bi a e Downg ade (Kbps), Tes I.
Figu e 55: Use Case Analysis - Bi a e Downg ade (Kbps), Tes II.
Bo h igu es exhibi highly simila ou comes conce ning hei ela ionship wi h he
swi ching poin . In bo h ins ances, emaining below he h eshold alue o a speci ic
du a ion wi hou possessing su icien bu e capaci y o con en playback yields speci ic
a i ac s and igge s he subsequen swi ch o he DTT ne wo k. Howe e , an impo an
conclusion d awn om he compa ison be ween bo h se s o esul s is ha a i ac s a e no
70
solely associa ed wi h s eep bi a e d ops, as he ini ial esul s had indica ed. The e o e,
i is possible o a i ac s o mani es e en in he absence o such d ops, highligh ing a
di ec co ela ion wi h he bu e ’s capaci y.
I is also wo h men ioning he beha io o he applica ion in Fig 54. In his ins ance,
despi e no p io bi a e d ops, he applica ion, due o inadequa e bu e ing, op s o cease
s eaming en i ely. This leads o he de ice en e ing an a ypical s a e associa ed wi h he
alley un il he nex da a peak. Fu he mo e, he ne wo k ansi ion mus be execu ed
swi ly o minimize he impac on Quali y o Expe ience (QoE). To illus a e his ansi ion,
he imes when he 5G se ice is los and he shi o DTT occu s ha e been ma ked.
9.2 Delay and QoE Deg ada ion
Inc easing delay and i s luc ua ion, o en e e ed o as ”ji e ”, esul in many
consequences and epe cussions ha subs an ially a ec he pe o mance o he s eaming
se ice. These signi ican ly impac he QoE and may lead o a us a ed iewe , as
p olonged bu e ing, in e up ions, and poo quali y may esul in a decline in use
sa is ac ion and engagemen . Comp ehending hese consequences is c ucial o enhancing
he pe o mance o s eaming se ices. G an ing a smoo h use expe ience is manda o y,
especially in scena ios whe e low la ency and high quali y a e pa amoun . This delay
inc ease is expec ed o be he ou come o an o e loaded ne wo k, whe e mul iple use s a e
eques ing high h oughpu ideo deli e y simul aneously.
This es aims o analyze he impac o a i icially and g adually inc easing he
ne wo k delay on mul imedia s eaming se ices. Fi s , he delay is inc eased g adually
un il a easonable maximum alue. Second, once his poin is eached, he es mo es o a
second phase whe e he ji e impac is analyzed while keeping he delay cons an . I is
c ucial o unde s and ha modi ying hese pa ame e s esul s in di e en beha io s and,
consequen ly, di e se a i ac s ha a ec he pe cei ed quali y by he use .
The same empo al pa e n as in he p e ious es s is ollowed o he simula ions,
inc easing he delay e e y 30 seconds. Tha is o say, he delay is p og essi ely inc eased
up o a alue o 100 ms. Subsequen ly, he ji e is adjus ed up o a alue o 50 ms. This
combina ion (100 ms delay and 50 ms ji e ) ep esen s a c i ical poin , o cing he es s
o s op as he applica ion’s beha io became exceedingly uns able. In a simila way o he
p e ious es , he ollowing commands a e execu ed a he a o emen ioned ime in e als:
# The i s alue in ms is ela ed o he delay, while he second
# is ela ed o he de ia ion (ji e )
# The ollowing is execu ed he i s ime o c ea e he con igu a ion
c qdisc add de un1 oo hadle 1: ne em delay 0ms 0ms
# Execu e his e e y 30 seconds wi h he desi ed alues
c qdisc epalce de un1 oo ne em delay 20ms 10ms
The ob ained esul s, depic ed in Fig 56, a e o signi ican in e es . I is impo an
o no e ha he e was no bi a e limi a ion in hese es s, and he obse ed ends and
pa e ns a e di ec ly linked o he applica ion’s bu e managemen once again.
71
A downwa d end in bi a e as ne wo k delay inc eases is shown du ing he ea ly
phase. In addi ion o he educ ion in bi a e, he e is also a no iceable dec ease in i s
a ia ion ange. Simila o he p e ious case s udy, his beha io p e en s he applica ion
om illing he bu e , esul ing in a i ac s. Howe e , due o he absence o a bi a e
limi a ion, he de ice can manage i and eques esou ces, ep esen ed by he p ominen
peak o 8 Mbps in he cen e o he g aph.
Subsequen ly, he bi a e s abilizes a alues close o he ideo’s mean bi a e
(15:31:06, 2.8 Mbps). Howe e , as ji e inc eases, he beha io becomes ema kably
uns able and signi ican ly de ia es om wha was obse ed in he ini ial phase. In his
scena io, he inc ease in ji e is di ec ly linked o an inc ease in bi a e a ia ion, e en ually
becoming so uns able ha e y low alues a e eached. The bu e canno load su icien
da a, esul ing in con inuous a i ac s ha se e ely impac se ice quali y.
Gi en he applica ion’s inabili y o eco e , his junc u e p esen s an ideal momen
o igge he ansi ion o he ATSC ne wo k.
Figu e 56: Use Case Analysis - Delay/Ji e In oduc ion.
72
