Tesis previa a la obtención del Título de Ingeniero en Electrónica y ...

,5 Multipoint operation
is híghly desirable thal lermínals not having any auxiliar)' dala equípmenl be able lo open LSD and/ur HSD channels so
lat they could particípale in mullipoinl comnuinieatmns wiihoul losing video. This could be extended 10 the use of MLP
id/or H-MLP, bul is for furlher siudy.
>ther aspects of muliipoinl operalion nf the terminal are under xludy.
ínter Communications
he mechanisms for iniercommunicalion wilh other .servicies are described in Ihe H.200/AV.240-Series Recommenatíons.
.1 Intercommunication between different visual telephone terminal types
, common mode of aperalíon i.s delermíned a.s described in 3.4.1. I)-channel signalling shuuld include new LLC and
!LC which are appropriale for audiovisual services, bul Ihis .sul)ulause i.s for furlher sludy.
.2 Intercommunication with telephony
NOTE - Descriplion of this subulauss is fnr Communications using a li-uhannel.
.2.1 Intercommunication with ISDN telcphune.s
L cali from a visual lelephone to an 1SDN lelephone is firsl plar.ed as an audiovisual cali, bul Ihe ISDN lelephone reiurns
icompaiible desiination orihe neiwurk reiurns recuivery on limerexpiry in case of no responses from Ihe called side, ihen
le visual lelephone may .swíich lo a spee.ch or 7 kHx auiüii liearer .servicie cali.
, cali from ISDN lelephone lo a visual [elf.plume is Mt'.uepted hy ihe visual leleplione. het:austi every audiovisual terminal is
quípped with this lelephone capahilily as a minimum fuiíulion.
'or both of Ihe abo ve cases, ihe ope rallona I mode of com ni un lea I ion is 0.71 1 speech or G.722 audio.
.2.2 ínter cora mun i catión with PSTN telephone.s
t cali from visual lelephone 10 a PSTN lelephone may be ínilialed as an audiovisual cali, bul (he nelwork reiurns no roule
D destinatíon, ihen the visual lelephone may swilch lo a sptsetih or 3.1 kHv, audio bearer service t:all. The operalional
of communication is G.711 audio iiti
I cali from a PSTN lelephone is routed inlu ihe ISDN as a 3.1 kHv audio cali which can be responded by Ihe visual
elephone for the same reason as described in 5.2.1. The operalion a I mode nf f.omniunicaikm ¡s 3.1 kHv, audio.
1.3 Intercommunication with other audiovisual termináis
^ common mode of operalion is delermined auunrdiny lo Ihe H.20()-.Se.rÍes Recommendalíons.
í Maintenance
lome loop-back funclions are envisaged lo aílow verificalion of thtí i'unclional as penis of Ihe terminal ín order lo ensure
.orrect operalion of ihe sy.stem and .snlislaclory qualiiy o!' ihe serviue lo Ihe remole party. The f'ollowíng loop-back
unctions (see Figure 2) are envisaged:
a) Loop at lerminal-neiwork inle.r!'ace (imvard.s nelwork)
Upon receíving ihe digital loop-back HAS, loop-back is aclivaled ai ihe digital mterfaee of the terminal
lf.iM,V loward Ihe network side. In ua.se of a múltiple. B/Ho channel arrangement, [oop-bauk is aclivaled in each
connection.
Kecommendation H.320 (03/93) 11