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01-02/2015 —

TELE-audiovision International —


This quick and easy feature

truly proved its worth in our

test center, since we have of-

ten spent hours on end set-

ting up an IPTV multicast cli-

ent only to discover down the

road that the server had not

been configured correctly in

the first place. A mistake we

made more often than we

would have liked was setting

up different IPTV servers with

different ports (good), yet us-

ing the same multicast IP (not

so good). With the handy De-

viser S7000 you’d notice such

a glitch immediately.

Yet – and you might have

guessed already – the IPTV

option of the Deviser S7000

offers much more than that.

Click on any of the listed IPTV

servers to access the IPTV

measuring menu, which sum-

marises all major stream pa-

rameters. Delay times, for

instance, are always a domi-

nant issue and the S7000

provides a very useful graphic

overview. Other standard

IPTV parameters such as

MDI (media delay index), DF

(delay factor) or MLR (media

loss rate) are of course also

available at a glance. Making

use of the entire screen of-

fered by the S7000, Deviser

has found a way to present all

those different details simul-

taneously using a design that

is both practical and pleasing

to the eye.

With the TS MEAS func-

tion it’s possible to launch

the built-in transport stream

analyser for the currently se-

lected IPTV server. Inciden-

tally, this is the very same

TS analyser that also deals

with the measurement of ca-

ble, terrestrial and satellite

signals. The Deviser S7000

simply passes through the

IPTV transport stream to the

TS analyser, which is a smart

move because the latter could

not care less about the origin

of the transport stream it dis-

sects. As a matter of fact, it

might as well come from a TS

file stored on an external USB

storage medium that is con-

nected to the meter.

If you want to refresh you

memory as regards the huge

range of features and capa-

bilities of the integrated TS

analyser we suggest you have

a read of TELE-audiovision

issues 09-10/2013 and 11-

12/2013 again, which both

featured in-depth reviews of

the Deviser S7000. All those

features and functions can

just as well be used for IPTV

analysis, so you can be sure

that there is nothing left to be


With the most recent firm-

ware update Deviser strik-

ingly proves yet again that its

S7000 meter is the flagship in

TV signal measurement. With

the new IPTV option both in-

stallers and head-end techni-

cians are given important ex-

tra functions for quickly and

efficiently diagnosing errors

and malfunctions.

In addition, this new firm-

ware reminds us of all the

core benefits the Deviser

S7000 has built in right from

the start. Its modular hard-

ware and software design al-

lows the meter to be kept up

to date and ahead of the pack

throughout its service life.

The manufacturer’s code-

based approach to add ad-

ditional functions is another

tool for extended customi-

sation. You only have to get

what you really need, which in

itself is a strategy worth ap-


Why You Need to Measure IPTV

IPTV frees the technician from worries regarding the

common problems of the distribution through a coaxi-

al cable network, like signal attenuation, distortion, etc.

However, new issues arise: because IPTV uses informa-

tion packets sharing the medium with other information

packets, timing becomes important. Problems occur if the

bandwidth is too high or if delays keep the required IPTV

packets from reaching the decoder in time.

To measure what is happening in the IPTV distribution,

several parameters can be measured. The most important

ones being:

Media Delivery Index (MDI)

– This represents the ra-

tio between the Delay Factor (DF) and the Media Loss Rate


Delay Factor (DF)

– This measures how big the buffer

on a virtual receiver has to be to avoid picture loss due to

the time distortions (jitter). In other words: if the packets

arrive with a delay greater than the delay factor there will

be an interruption in the picture.

Media Loss Rate (MLR)

– This indicates the number of

packets lost per second.