IT4680 Ch4 Communication Multimedia

8/3/2019 IT4680 Ch4 Communication Multimedia

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Multimedia CommunicationNguyen Thi Hoang Lan

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IT4680Truyn thng a phng tin

v ng dng(Multimedia Communication)

PGS.TS Nguyn Th Hong LanB mn Truyn thng v Mng my tnh

Vin CNTT&TT - HBK H [email protected]


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Chng 4CC GIAO THCV K THUT TRUYN

H truyn thng a phng tin trn mng IP Gii thiu cng ngh truyn s liu tc cao

Cc giao thc truyn thng a phng tin(RTP/RTCP, ) Cc chun giao thc H323 v SIP

K thut truyn dng d liu a phng tin(Data Streaming) Truyn n hng, a hng (Unicast, Multicast)


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H truyn thng a phng tin trn mng IP H thng truyn thng a phng tin cn p ng yu cu c

s lng thu bao ln (v d mng in thoi), din rng v kh

nng tng tc thi gian thc. Yu cu truyn thng phi kt hp truyn nhiu loi thng tin cc tnh vt l khc nhau trn cng mt ng truyn :- nh, video, m thanh ting ni, vn bn, c di ph rt khc

nhau v c yu cu khc nhau v tc , tr.- K thut truyn video c khc nhau theo yu cu ng dng.. Cc vn ca h thng truyn s liu a phng tin :

- X l d liu a phng tin: m ho nn, ng b

- Chng giao thc, ng gi DL, KT truyn dng d liu Yu cu v gi thnh kh thi v m bo cht lng QoS ti

my ngi dng cm nhn thng tin


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Gii thiu cc cng ngh

ng truyn s liu a phng tin

Kin trc HDSL- Mc cao : n vu cuiHDSL vi vng dch v CSAcho khch hng, chun ANSI

TI.403-1989.- Trung tm thng tin in thoi,- Tc truyn/ nhn: 800Kb/s,- Truyn hai chiu ng thi (full

duplex) : 1.5 Mb/s- ng truyn vt l:fullduplex, Twisted-pair copper wire

HDSL (High-Bit-Rate Digital Subscriber Line)


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c tnh k thut ca HDSL S dng vi mch VLSI thc hin qu trnh nn v iu ch, S m ho 2B1Q : t hp cp bit thnh 4 t hp 00 01 10 11,

bn t hp ny c dng trong siu ch, Phng php iu ch : QPSK hoc QAM

- QPSK (Quadrature Phase Shift Key) : 4 t hp bit c iuch thnh cc sng lch pha 45 .

- QAM (Quadrature Amplitude Modulation) : 2 sng mang lchpha 90 c s dng iu ch d liu nn. ng truyn vt l 2 chiu: mt ng truyn d liu video/

audio iu ch, mt ng truyn tn hiu K v ng b.

Cc vn cht lng cn x l : li giao thoa gia 2 ng,giao thoa tn s, s suy gim tn hiu trn ng di, nhiu ...

Gii hn : ng di t 9 n 12 feet, 1.54 Mb/s vi mi chiu.


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ADSL (Asymmetrical Digital Subscriber Line)

Cng ngh ADSL c nhiu im tng t HDSL. Tc truyn khng i xng, ha ra tc 1.544 Mb/s

theo hng ti mng, h nhn tc 9 Mb/s theo hng khc.

ng truyn vt l : cp i dy ng xon (Twisted-paircopper wire). Truyn video, m thanh, nh theo mt chiu, cctn hiu iu khin c truyn theo chiu ngc li trn cngmt ng.

Cng ngh HDSL v ADSL u ph hp vi truyn videochun vi 30 khung hnh/ giy.

ADSL dng khong cch t 12.000 n 18.000 feet (5490 m). HDSL dng cho khong cch n 12000 feet (3660 m) Nn 2 mc: nn bng tn tn hiu, nn d liu, lc gim nhiu. iu chbin bnh phng. X l : dng cc b lc gim nhiu v sa mo.


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Truyn dliu videotrn ADSL

Linecoder

Transmitfilter

Receivefilter

Datadecoder

Videocompression

Videodecompression

Kin trc ADSL


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Cc cng nghng truyn vt l

Twisted-pair copper wire : cp i dy ng xon, khi kt hpvi cc vi mch VLSI v VHSIC cho php thc hin bng mchcng cc chc nng : m ho, iu ch, truyn d liu, nhn, giiiu ch, gii m tn hiu s v lc nhiu sa mo khi truyn,

t tc truyn cao. Cp ng trc (coaxial cable) : CATV (Community Access TVsystem), di tn rng (broadband), h thng truyn hnh.

ATS (Analog Transmission System) : h thng truyn tn hiu

lin tc video trn ng truyn di tn hp.- u im : thc hin n gin, ga thnh r, trn mt ngtruyn ng thi 2 dng, dng tn hiu video v tn hin ngb, d dng truy cp vo h CATV, truyn khong cch xa.

- Nhc im : cn thm tng khuch i khi khong cch xa,kh tng thch cc h thng s, n vu cui phi xc nh. Mng cp quang (fiber optic cable) : FDDI, SONET Mng khng dy (Wireless) : truyn sng radio, sng viba.


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Cng ngh mng truyn dliu

a phng tinFDDI (Fiber Distributed Data Interface)

Cng ngh FDDI : chun cho cc mng cp quang, dng

cho mng LAN, MAN, WAN, theo chun ISO 9314. Cc c tnh ca cng ngh mng FDDI- Thng lng : 100 Mb/s- Kin trc mng vng kp, cc kiu mng Ethernet,

Token-Ring, DECNet, TCP/IP- Phng php truy nhp c iu khin : dng thbi- ng knh mt vng khong 31 km, khong cch ln

nht gia hai nt l 2 km- a ch : 16 bit, 48 bit, chun IEEE 802.2- Giao thc ch y : TCP/IP- M d liu truyn : 4B/5b-NRZI


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Mng FDDI

Kin trc mng FDDI- Tng vt l gm 2 tng con : PMD (Physical MediumDependent) va PHY (PHYsical layer protocol)

- Tng lin kt d liu gm 2 tng con : MAC (MediumAccess Control) va LLC(Logical Link Control)

- Tng qun l tr m SMT (Station Management) : qun lhai kiu dch v : ng b / khng ng b.

Mng FD DI v vn truyn thng a phng tin- Vi thng lng100 Mb/s, mng FDDI c th truyn s

liu a phng tin nhng b hn ch v khng phi lun

lun m bo tc theo yu cu,- Trong kiu truyn ng b, thi gian truy nhp chp,

- Gi thnh backbone cao.


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Cng ngh mng chuyn mch nhanh

ATM (Asynchronous Transfer Mode)

Mng ATM v vn truyn thng a phng tin- Mng ATM kt hp vi cng ngh mng B-ISDN

(Broadband Integrated Services Digital Network) nhm thchin dn knh v chuyn mch vi tc cao, tr nh.- Mng ATM cho php p ng vi yu cu truyn thng aphng tin v c kh nng truyn mi loi d liu thng tin,

tc truyn v x l cao, t ti thng lng vi trm Mb/s. Kin trc mng ATM- Mng ATM bao gm tp hp cc nt u cui CPE v cc

trung gian chuyn mch ATM (ATM switches), c kt ni

theo nguyn tc im-im v im-a im- C 2 loi giao din : UNI ( User-to-Network Interface) vNNI (Network-to-Network Interface), tham s VPI nhdanh ng o, tham s VCI nh danh knh o.


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Kin trc mng ATM

CPE

CPE

CPE

ATMSwitch

ATMSwitch

ATMSwitch

UNI

UNI

UNI

NNI

NNI

NNI

Public B-ISND Network

UNI : User to Network InterfaceNNI : Network to Network InterfaceCPE : Customer Premise Equipement


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- T bo ATM : n v d liu truyn vi kch thc c nh l

48byte + 5byte thng tin iu khin, t bo UNI khc vi NNI.- Kt ni : Cng ngh truyn theo kiu hng kt niKt ni trong mng c thc hin bi VC (Virtual Channel) vVP (Virtual Path) da trn cc chuyn mch nhanh ATM switch

A B C D

Kt ni ATM gia 2 nt u cui N1 v N2

N1 N2VC1

VC switchVP switch

VP1

VP2

VP3

VP1

VP2

VP3

VP1 VP1

VP2 VP2

VP3 VP3

VC2 VC3

VC4VC3VC2

VC1VC2VC3

VC1VC2

VC3

VC1VC2VC3

VC1VC2VC3

VC1VC2

VC3

VC1VC2VC3

Cc chuyn mch ATM


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Truyn s liu trong mng ATMNguyn tc thit lp kt ni

Thit b u cui N1 gi yu c n UNI, UNI truyn yu cun mng,

Gi thit mng chn

ng A-B-C-D : mi nt s dng nhng VCm hin khng s dng kt ni, v d A chn VC1, t bo dliu t N1s mang nhn VC1 khi i ra khi A,

Nt A gi t bo d liu ti B, B s thay i VC1 thnh VC2 vgi ti C,

Ti nt C, VC2 c kt hp vi VC3 v gi n D, Ti nt D, VC3 c kt hp vi VC4, nt D s kim tra thit b

u cui N2, nu UNI ca N2 ri th t bo c mang nhn VC4

gi n N2. Nh

vy N2 s dng VC4 kt ni vi nt D. D s gi li t bo n C, C kt hp VC4 vi VC3 gi n B, B kthp VC3 vi VC2 gi n A, A kt hp VC2 vi VC1 chuyn nN1. Nh vy s kt ni gia N1 v N2 c thit lp.


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Truyn s liu trong mng ATM (tip)

Khi kt ni c thit lp, N1 gi sliu ti ng truyn v cc gi trtham s VCI/ VPI c tr t do phc v cho kt ni khc,

Khi ng kt ni c thit lp, ttc cc t bo c truyn lin tiptrn cng mt knh o, m bo cct bo c truyn theo trnh t lin

tip n ni nhn, Cc tham s ca cht lng dch v

truyn : tc truyn dn, mc mt t bo, tr, tr bin thin,

Vn c th xy ra tc ngn mchtrong mng ATM

ng truyn vt l : SONET/SDH

Cu trc ca giao thcATM : Physical ATM,ATM layer, AAL

Physical Layer

ATM LayerATM AdaptationLayer

Higherlayers

Higherlayers

ControlPlane

UserPlane

ManagementPlane


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K thut Frame Relay

n v d liu truyn c kchthc thay i, gi l frame,khun dng ca Frame Relaygn ging frame HDLC, khc

phn thng tin iu khin. Thng lng : 2 Mb/s, c th

dng cho truyn thng aphng tin.

Ti mi nt mng c chngtrnh iu khin Frame hanlerthc hin chn ng n gin,nhanh cho cc frame v thc

hin pht hin li. Vic sa lic thc hin ti nt ch. Vn tc ngn ng truyn

Frame Relay System


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Cc giao thctruyn thng a phng tin

Cc giao thc trn mng IP: TCP, UDP Giao thc truyn thng thi gian thc

RTP/ RTCP , RTP : Real-time Tranfert ProtocolRTCP : Real Time Control Protocol

Protocole RTSP : Real Time Streaming Protocole

RSVP : Real-time Reservation ProtocolSAP : Session Announcement ProtocolSDP : Session Description ProtocolSIP : Session Initiation Protocol

Mt s giao thc khcTP5, TP ++ , XTP (eXpress Transport Protocol),NETBLT (NETwork Block Transfert) - MIT


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Phn loi cc giao thc truyn thnga phng tin

Phn chia theo tng. Tng ng dng: RTP/RTCP, SIP, SAP, RTSP Tng truyn ti: TCP, UDP Tng mng: IP

Phn loi theo chc nng. Cc giao thc truyn d liu: RTP, RTSP Cc giao thc iu khin: RTCP, RTSP, SIP

Chng giao thc v chun:- H323- SIP


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Khung giao thc truyn thng a phng tin


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Giao thc truyn thng thi gian thcRTP/ RTCP

Giao thc RTP/ RTCP l cp giao thc tng ng dng, chy

trn nn UDP/IP, c thit k bi t chc IETF v hin nay tr thnh chun khuyn ngh ITU-H323 cho hi ngh aphng tin.

Giao thc RTP (Real-Time transport Protocol) RTP c thit k phin bn u nm 1992 Gi RTP cha trong gi UDP/ IP RTP c thit k dng cho truyn dng video-audio, phn

phi d liu thi gian thc theo a hng n nhiu ngi(multicast), hoc n hng (unicast), cho php tng tctheo m hnh a im hoc im - im


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Giao thc RTP (tip)nh dng phn Header ca RTP

RTP cung cp cc thng tin ch yu : Cc thng tin v nhn thi gian (Timestaming), S th t cc gi (Sequence Number) cho php pht hin

mt gi, pht hin li, Xc nh nh dng gi d liu (Playload Type- PT), chophp thm nh ngun d liu (SSRC).


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Giao thc RTCP (RTP Control) RTCP l giao thc iu khin c thit k hot ng

kt hp vi RTP. RTCP cung cp cc thng tin v cc

gi tin nhn c, cung cp thng tin phn hi theodi v cht lng dch v hi ngh v thng tin v ccthnh vin tham gia hi ngh gip kim sot phinlm vic.

Cc chc nng ch yu ca RTCP Chc nng cung cp thng tin phn hi v cht lng

phn phi d liu. Mi gi tin RTCP c hai trng nhn

thi gian cho php khi phc li thi gian gi tin cgi ti pha nhn


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Giao thc RTCP (RTP Control) RTCP mang mt nh danh tng giao vn cho ngun RTP

gi l tn quy tc (CNAME) xc nh duy nht mt thnh

vin trong hi ngh, cc kt ni RTP khc nhau c cc SSRCkhc nhau, nhng xut pht t mt ngi tham gia s ccng CNAME. Ti ni nhn s dng CNAME xc nhcc lung d liu t mt thnh vin trong mt tp hp cc

phin RTP ng b video, audio.

RTCP c nm loi gi tin SR (Sender Report): Thng bo ca ngi gi, c to ra

bi ngi ang gi, SR cha cc thng tin nhm ng b ccgi tin, thng k vic truyn v nhn t cc thnh vin lngi ang gi.


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Giao thc RTCP (RTP Control) RR (Receiver Report): Thng bo ca ngi nhn, c

to ra bi cc thnh vin khng l ngi ang gi (active

senders), cha cc thng tin phn hi v d liu nhn ckm theo s gi tin ln nht nhn c, s gi tin mt, tc nghn, cc nhn thi gian ca cc gi cho php tnh tr gia ngi nhn v ngi gi.

SDES (Source DEScription items): Gi m t ngun, chathng tin m t ngun gi.

BYE: Gi xc nh vic kt thc tham gia trao i thng

tin, bo kt thc phin lm vic. APP (APPlication specific functions): Dng pht trin

cho cc ng dng c bit.


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Giao thc RTCP (RTP Control)

0 1 2 3

0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

|V=2|P| RC | PT=SR=200 | length | header

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

| SSRC of sender |

+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+

| NTP timestamp, most significant word | sender

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ info

| NTP timestamp, least significant word |

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

| RTP timestamp |

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Phn thng tin ngi gi trong gi tin Sender Rport

ca RTCP


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SIP: Session Initiation ProtocolGiao thc thit lp phin SIP c nghin cu t 1996 bi nhm IETF Cc phin bn: SIP 1.0 RFC 2543, SIP 2.0 RFC 3261 SIP l giao thc tng ng dng theo m hnh OSI thit lp

phin truyn thng bao gm: nh v ch (user location), xc nhkh nng (user capability), xc nh ch sn sng v tham struyn ti d liu media (user availabilty), mphin thit lp cucgi (call setup) qun l phin (session management), x l cucgi (call hadling) v kt thc phin (session close). Bn thn SIP khng nh ngha ton b giao thc truyn thng,SIP c thit k di dng cc thnh phn cho php kt hp vicc giao thc khc to nn kin trc truyn thng hon chnh,SIP c kt hp vi RTP/RTCP, SRVP, SDP SIP s dng ch yu UDP, hot ng trn nn IPv4, IPv6.


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Khung giao thc truyn thngthi gian thc SIP


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Cc thnh phn kin trc h thng SIP

Kin trc gm 2 thnh phn c bn :User Agent (UA) v NS( Network Server )

UA (User Agent) gm UAS v UACUAS (User Agent Server) : Server nhn, x l cc yu cuUAC (User Agent Client) : Client ngi dng, sinh cc yu cu

NS (Network Server )PS (Proxy Server) : nhn v x l trc khi tip tc truynRS (Redirect Server) : gi yu cu n PS gn nhtLS (Location Server) : Server nh v, cung cp cch xc nha ch min v ngi dngRG (Registrar) : Server ng k


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Kin trc h thng SIP


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Thng ip SIP

Hot ng ca SIP da trn vic trao i cc thngip bn tin (message) gia cc thc th trong h thng,cc bn tin di dng vn bn text tun theo nh dngRFC 2822 tng t HTTP. a ch SIP c nh dng:

sip: user@domainuser: Tn hoc s in thoidomain: Tn min hoc a ch IP

V d : SIP: [email protected]: [email protected]: [email protected]


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V d thng ip bn tin ca SIP


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Thit lp cuc gi qua proxy SIP server


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Chun khuyn ngh H323Cu trc cc thnh phn


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Multimedia CommunicationNguyen Thi Hoang Lan 34

Chun khuyn ngh H323


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Chun khuyn ngh H323


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Chun khuyn ngh H323


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Chun khuyn ngh H323


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Giao thc H323


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Chng giao thc H323Khi nim: Chng giao thc (khung giao thc) l mt m hnh

truyn thng s dng nhiu giao thc to thnh cc tng giao

thc khc nhau. Mi tng c mt nhim v ring trong qutrnh truyn thng a phng tin. H.245: giao thc bo hiu iu khin truyn thng multimedia. H.225.0: ng gi v ng b cc dng thng tin a phng

tin (thoi, truyn hnh, s liu). Khuyn ngh ny bao gmgiao thc RTP/RTCP v cc th tc iu khin cuc gi Q.931(DSS 1).

Cc chun nn tn hiu thoi: G.711 (PCM 64 kbps), G.722,G.723, G.728, G.729,

Cc chun nn tn hiu video: H.261, H.263, H264, T.120: Cc chun cho cc ng dng chia s s liu.


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K thut truyn d liua phng tinBn phng php truyn dliu tserver n clent

Download and Play

Server Client

Streaming

Server Client

Progressive Decompression

Server Client

Page at a TimeServer Client

Data file

Data Data Data Data

Data Data Data Data

Data Data Data


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Multimedia Communication

Nguyen Thi Hoang Lan

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4 phng php truyn dliu a phng tin Phng php truyn file (Download and Play)- phng php

kinh in (Traditional DBMS): ton b d liu audio-videoc tch hp v lu tr trong khun dng file, ton b file phic truyn ti download n ni nhn trc khi trnh din(play back).

Dng dliu (Data Streaming- DSMS) t Serverc nn,ng gi v c truyn i lin tc khi c cc yu cu truy cp

d liu video - audio, pha client nhn d liu mgi, gii m,trnh din (player) lin tc ngay trong qu trnh ang truyndng v m bo thi gian thc khi th hin trnh din.

Truyn (download) lu tin (Progressive Download file/

Decompression): Download v truyn dn dn cc thnh phnv th hin Phng php truyn trang mi thi im (Page at time):

Cc trang d liu c truyn lin tip theo yu cu client nhn.


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Truyn dng d liu (Data Streaming) Khi nim

Truyn dng l k thut truyn d liu m trong d liu cclient nhn v hin th mt cch lin tc, ng thi vi qu trnhgi tpha server.

pha Server, dng d liu c a vo mng nh mt dngchy lin tc gm cc gi d liu c th t.D liu c a vomng nh mt dng lin tc vi cc k thut ng gi d liu vnhp truyn

K thut truyn dng (Data Streaming) Cu trc h thng s dng Streaming Server S dng giao thc UDP Qu trnh truyn DL ng thi vi qu trnh trnh din ti ni nhn Truyn d liu vi tc ph hp tc trnh din file. D liu trnh din xong khng lun lu tr thit b vt l.


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Nguyn tc truyn dng dliua phng tin (Data Streaming)

Gii nnvideo/audio

Gii nnvideo/audio

Nn

video/audio

Nn

video/audio

RTP

Packets

Phn giPhn gi

Khi phc d liuv ng b

Khi phc d liuv ng b

Network

Dng

video/audio


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Data Stream Management System

User/ApplicationUser/Application

Register QueryRegister Query

Stream Query

Processor

ResultsResults

Scratch SpaceScratch Space

(Memory and/or Disk)(Memory and/or Disk)

Data

StreamManagement

System

(DSMS)


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Cc vn k thut truyn dng(Data Streaming)

Traditional DBMS data stored in finite, persistent data setsdata sets

Data Streaming- DSMS (Data Stream Management System):Data input network as continuous, ordered data streamsdata streams

CCcc kk thuthutt nnnn::-- XX ll dd liliuu:: nnnn dd liliuu,, ngngbb,, ttchch hhpp dd liliuu

-- PhnPhn ggii dd liliuu (ALF(ALFApplication Level Framing)Application Level Framing)+ NDU (Network Data Unit)+ NDU (Network Data Unit)

+ ADU (Application Data Unit)+ ADU (Application Data Unit)

-- TT dngdng cccc ggii dd liliuu,, aa lnln mmngng linlin ttcc theotheo nhnhpp-- PhPhngng ththcc truytruynn:: UnicastUnicast, Multicast, Multicast-- ChChtt llngng ddchch vv -- QoSQoS truytruynn thngthng aaphphngng titinn


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Truyn lu tin

Streaming vs. Progressive Download. Truyn dng v truyn ly tin l hai khi nim d gy nhm

ln i vi ngi dng xem phim online trn Web. Progressive Download:

Dng Web Server. File c lu tr trong Web Server. Giao thc HTTP c s dng truyn thng gia Client v

Server (s dng Web Browser) S dng giao thc TCP. Truyn vi tc tt nht c thph thuc mng. File c Download dn tng phn kt hp vi trnh din File ch c trnh din khi nhn mt lng nht nh

no y (thng c quy nh bi Web Browser hocMediaplayer)


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u im ca Streaming so viProgressive Download file S dng bng thng hiu qu hn: Khng cn truyn li, khng s

dng cch thm d tc nghn (truyn t tc thp ri tng dn). Cht lng cm nhn audio v video n ngi dng tt hn: Khi xy

ra tc nghn, Server c th gi nguyn dng audio, gim dng video trnh tc nghn. Mt khc gi tin UDP c u tin cao hn so viTCP nn cng hn ch ngt qung pha ngi dng.

H trtruyn thng tng tc thi gian thc: Window Media Servicesc th h trcc tnh nng nh VCR controls (Fast-forwad, Seek,Rewind), truyn hnh trc tip, multicast. y l nhng tnh nng khthc hin bng Web Server.

Chi ph thp hn khi phc v s lng ln ngi dng.

Bo vphm bn quyn: Khi truyn ly tin, file c lu li trongmt th mc tm thi nn ngi dng c th coppy hoc xem li. Vitruyn dng, ngi dng khng th coppy v mun xem li th li phirequest Server truyn li.


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Phng thc truyn n hng/a hng (Unicast, Multicast)

Unicast Multicast


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PhPhngng ththcc truytruynn nn hhngng//aa hhngng ((UnicastUnicast, Multicast), Multicast)

Date post:	06-Apr-2018
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IT4680 Ch4 Communication Multimedia

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