T ansmission o High Powe Senso Sys em and
DWDM Da a Sys em in One Op ical Fibe
Milan Cucka, Pe Muns e , Lukas Koci, Tomas Ho a h, Milosla Filka, and Jose Voj ech
Abs ac —This a icle deals wi h he possibili y o employing
phase sensi i e OTDR (Op ical Time Domain Re lec ome y) in o
ibe s wi h ac i e da a ansmission DWDM (Dense Wa eleng h
Di ision Mul iplex). Due o he low backsca e ed signal o phase
sensi i e OTDR is equi ed o gene a e pulses wi h a high in en-
si y and sho ime du a ion. These high powe pulses can cause
deg ada ion o he da a ansmission. By using VPIpho onics
so wa e we pe o med he simula ions in es iga ing he in luence
o phase sensi i e OTDR o quali y DWDM connec ions and we
a e also in e es ed in he wa eleng h spacing be ween senso ic
sys em and da a sys em. In ou a icle i was e i ied ha phase
sensi i e OTDR and da a ansmission can be ac i e oge he in
one op ical ibe . I bo h sys ems wo k e y close o each o he i
will lead o deg ada ion o da a ansmission. We ha e e i ied
ha da a ansmission may be a ec ed i powe o pulses exceed
13 dBm.
Index Te ms—DWDM, Phi-OTDR, Pulse gene a ion, Backsca -
e ed signal, Simula ions, VPIpho onics.
I. INTRODUCTION
Nowadays op ical senso s a e used hanks o hei abili ies
o sense high empe a u es, ib a ions and mechanical ension.
One big ad an age is accu acy o measu emen and compac
po able ins umen packages. Fo example, ib a ion senso s
a e pu on al eady exis ing ou es and a e used o ack any
mo emen a ound he ou e. Ano he commonly used ype o
op ical senso s a e senso s o empe a u e sensing due o hei
abili y o measu e high empe a u es. These ypes o senso s
can o e noncon ac measu emen .
Op ical senso s can be di ided in o wo g oups. The i s
g oup includes ex insic senso s wi h sensing ou side he ibe
and he second g oup is in insic ha means ha sensing akes
place wi hin he ibe i sel . This a icle ocuces on he in lu-
ence o φ–OTDR (Op ical Time Domain Re lec ome y) senso
and hei lase o he BER (Bi E o Ra e) o he DWDM
(Dense Wa eleng h Di ision Mul iplex) sys em. Using same
op ical ibe s o pa allel ansmission o a da a and a sensing
signals simul aneously is new and inno a i e idea.
The es o his pape is s uc u ed as ollows. Sec ion I
sho ly in oduce ibe op ics senso s and new ends. Sec ion II
Manusc ip ecei ed No embe 30, 2015; e ised No embe 7, 2016 and
No embe 22, 2016.
Resea ch desc ibed in his pape was inanced by he Na ional Sus ainabil-
i y P og am unde g an LO1401, and SIX CZ.1.05/2.1.00/03.0072. Fo he
esea ch, in as uc u e o he SIX Cen e was used.
Au ho s a e wi h he Depa men o Telecommunica ions, B no Uni-
e si y o Technology, B no, Czech Republic and om CESNET,
z.s.p.o., P aha, Czech Republic (E-mails: [email p o ec ed].cz,
[email p o ec ed].cz, [email p o ec ed].cz, ho [email p o ec ed].cz,
[email p o ec ed].cz, [email p o ec ed]).
desc ibes ela ed wo k in φ–OTDR senso s. Sec ion III gi es
an o e iew abou DWDM sys em and in oduces unc ion
o φ–OTDR senso . Sec ion IV and sec ion V desc ibes ou
simula ion se up in VPIpho onics and discusses he esul s
achie ed in he simula ion. Sec ion VI concludes he pape and
desc ibes u u e wo k.
II. RELATED WORKS
Op ical senso s based on φ-OTDR we e i s in oduced in
2003 by Juan Ca los Jua ez. He published his esea ch wo k
abou op ical senso s in [8]. Fu he , φ-OTDR senso s a e
widely used as senso s o mechanical ib a ions o moni o ing
and secu ing na ional bo de s, oil and gaspipelines, mili a y
ins alla ions, s uc u al heal h e c.
Many sys ems use an ex emely na ow lase and EDFAs
(E bium Doped Fib e Ampli ie ). This sys em wo ks on a 4
km long op ical ibe wi h esolu ion o 50 m. A e de ec ion
da a a e p ocessed in Ma lab en i onmen . I is neccessa y
o il e he ecei ed signal. [9] desc ibes he issues bu does
no desc ibe using one op ical ibe o he de ec ion and
o da a ansmission. Nex issue o φ–OTDR is p ocessing
o ecei ed signal due o di icul il e ing and analyzing.
Fea u e ex ac ion o ime domain signals in hese sys ems
is ime-consuming and may lead o inaccu acies due o noise
dis u bances. The ecogni ion and speed o φ–OTDR sys ems
canno be used o online ib a ion moni o ing sys ems.
The wo k which is called Recogni ion o a Phase-Sensi i i y
OTDR Sensing Sys em Based on Mo phologic Fea u e Ex-
ac ion be e desc ibes his p oblem bu does no deal wi h
any simula ion o use φ–OTDR sys ems on elecommunica ion
ou es [10]. Ou a icle ocuses on simula ions in VPIpho onics
so wa e.
The au ho s in [11] desc ibe ampli ica ion o he φ–OTDR
sys ems, epe i ion a e and wid h o he pulses. They use
a simple me hod using he holding beam o ampli ying o
pulses wi h low epe i ion a e by s anda d elecommunica ion
EDFA boos e . The e a e desc ibed h ee me hods o φ–
OTDR signals ampli ica ion and hei e i ica ion by measu e-
men .
These a icles [12], [13], [14], [15], and [16] deal wi h
he same opics, pulse wid h, du a ion, epe i ion equency
and il e ing o he ecei ed signal. In compa ison wi h o he
a icles, ou pape looks a simula ion o φ–OTDR wi h
DWDM sys em on one op ical ibe .
190
JOURNAL OF COMMUNICATIONS SOFTWARE AND SYSTEMS, VOL. 12, NO. 4, DECEMBER 2016
1845-6421/12/8416 © 2016 CCIS
O iginal scien i ic pape
III. OVERVIEW OF THE SYSTEM
A. Dense wa eleng h di ision mul iplex sys em
T ansmission sys ems based on DWDM a e now o en used
o inc ease he ansmission capaci y o op ical ibe o bi-
di ec ional communica ion. I is a combina ion o se e al
wa eleng hs which ansmi mul iple lase s.
A ansmi e which ansmi s in o ma ion is modula ed
on each ca ie equency. A mul iplexo combines each
op ical channel wi h he op ical ibe . Fo n-channels con-
nec ion one mul iplexo /demul iplexo and also one modula-
o /demodula o a e needed. Each channel needs ligh sou ce
on speci ic wa eleng h.
DWDM echnology uses DFB (Dis ibu ed Feedback) lase
wi h ex emely na ow spec al line and highly selec i e spec-
al il e s. These de ices a e e y sensi i e o equency and
he mal s abili y. This is one eason why he echnology is
expensi e. The s anda d ITU-T G.694.1 speci ies he indi id-
ual ansmission channels a he wa eleng h in he ange om
1490 nm (200.95 THz) o 1620 nm (186.00 THz) called S, C,
and L band.
DWDM g id is based on a no malized pilo equency
193.1 Thz. The minimum spacing o each wa eleng h may
be 0.1 nm, which uses ul a na ow DWDM. To main ain he
s anda d i is necessa y o ha e a spacing o 0.2 nm. To ensu e
p ope unc ioning wa eleng h di ision mul iplexing i is bes
o choose a spacing o 0.8 nm.
B. Φ–OTDR op ical senso
Commonly used op ical ibe ib a ion sensing sys ems use
phase sensi i e op ical ime domain e lec ome e . Φ–OTDR
sys ems can de ec and loca e ib a ion signals by measu ing
he backsca e ligh ac oss op ical spec um. Senso ic sys-
em commonly wo ks wi h Rayleigh and B illouin sca e ing.
Phase sensi i e OTDR uses basic single mode op ical ibe
which is also used o ansmission. This ype o senso has
been used o moni o ing and sa e y condi ion o building
s uc u es, gas o oil pipeline s uc u es. Measu ing can be
eal- ime.
Sou ce o op ical adia ion sends beam o he ibe , i is sho
ime and high powe ed pulse which can p opaga e in op ical
ibe . Then he pa o ligh is con inuously backsca e ed
because o Rayleigh o B illouin sca e ing. This beam is
measu ed by p ocessing he backsca e ed signal. Cap u ing
and p ocessing o he signal is he mos used echnique. This
signal is sensed by he op ical ime domain e lec ome y.
Re lec ome ic sensing is e y use ul o de ec ion ib a ions
and hei localiza ion. Many dis ibu ed senso s use φ–OTDR.
Senso ic sys ems based on φ–OTDR can be used o moni o
mo e han one ib a ion sou ce along he op ical ibe .
This ype o sensing needs special pulses, because he
backsca e ed signal is e y low. The backsca e powe may
be desc ibed as [11]:
PR( ) = Pi·SγR ·W0·υg·exp−γ· g
·
2=PR(0) ·expγ· g
· ,
(1)
whe e γis he a enua ion coe icien and is equal o 1/20 h
o he g adien o a plo o Rayleigh backsca e a enua ion
in dB, Piis he inpu powe , γR is he Rayleigh sca e ing
coe icien .
The ac ion o cap u ed op ical powe is de ined o s ep
index ibe s as [11]:
S=NA2
4n2,(2)
whe e NA is nume ical ape u e and n is he ibe e ac i e
index.
A e his we can simpli ied he i s equa ion as [11]:
PR( )=7.8·Ep·exp−γ· g
· = 7.8·Ep·exp−2γ· g
· ,(3)
whe e we use γ= 4.6·10−5, NA = 0.12, n = 1.46.
¿F om hese equa ions we can see ha backsca e ed powe
is lowe han inpu powe . Fo a e age powe o 150 mW
and pulse du a ion o 200 ns. The le el o he backsca e ed
signal is abou 52 dB lowe compa ed o he inpu . S anda d
elecommunica ion op ical ibe has an a enua ion a ound
0.2 dB/km.
The pulse epe i ion a e is dependen on he maximal leng h
o he op ical ibe , pulse epe ion a e can be exp essed as [9]:
τ=2·L
υ=2·L
c/n (s)(4)
o ou measu e sys em du a ion o he pulse is [9]:
τ=2·L
c/n =2·40 ·103
3·108/1.46 = 3.89 ·10−4(s)(5)
whe e epe i ion a e can be calcula ed as [9]:
=1
τ=1
3.89 ·104= 2.57(kHz).(6)
IV. SYSTEM DESCRIPTION
Ou sys em desc ip ion can be di ided in o wo pa s. The
i s pa ocuses on dense wa eleng h di ision mul iplex, hei
unc ion and se ings. The second pa ocuses on φ–OTDR
sys em. Ou designed sys em is depic ed in Fig.1.
Recei ing pa
T ansmi ing pa
Senso ic sys em
pulses 130 ns,
epe i ion a e 2.57 kHz,
–30 dBm – +20 dBm
DWDM sys em DWDM sys em
Senso ic sys em
M
U
X
D
E
M
U
X
Op ical ibe
40 km, G.652.D
Fig. 1. Block schema ic o sys em
In ou sys em we use ou DFB lase s o DWDM sys em
and one DFB lase o ibe op ics senso . Lase o op ic
senso has wa eleng hs s a ing a 1550.5nm; 1551.0nm;
1551.5nm; 1552.0nm; 1552.5nm; and powe pe o mance is
a iable. These wa eleng hs a e used o in luence he i s
channel o DWDM. Senso ic sys em is shi ed om DWDM
sys em abou 0.5 nm and he ange o wa eleng h o senso ic
M. CUCKA e al.: TRANSMISSION OF HIGH POWER SENSOR SYSTEM AND DWDM DATA SYSTEM
191
sys em is inc eased in compa ison wi h DWDM. Cohe en
leng h o used lase o φ–OTDR is abou 750 Hz. This
leng h is used o 40 km op ical ibe . Lase s o DWDM ha e
wa eleng h o 1550 nm, 1550.8 nm, 1551.6 nm, 1552.4 nm and
powe 3 dBm. Da a sys em ansmi s da a 10 Gbi /s wi h BER
(Bi E o Ra e) abou 1.91E−40.
Fi s o all, we simula e he op ical pa h wi h 40 km op ical
ibe wi hou ampli ie s. We use s anda d elecommunica ion
ibe G.652.D wi h a enua ion 0.2 dB/km. In op ical ib es,
he a enua ion is mainly caused by wo physical ac o s,
abso p ion and sca e ing losses. Abso p ion is caused by ib e
ma e ial and sca e ing due o s uc u al impe ec ions wi hin
he ib e. Mic obending o op ical ib e also con ibu es o he
a enua ion o signal.
Ou simula ion con ains CD (Ch oma ic Dispe sion) and
PMD (Pola iza ion Mode Dispe sion) which a ec ing he
shape and cou se o he ansmi ed signal. I we ake in o
accoun hese e ec s, ou DWDM sys em has clea eye o he
decision.
A ansmi ing pa o DWDM sys em in VPIpho onics is
depic ed in Fig. 2. I is a module which gene a es pseudo
andom da a sequence. A ano he block gene a es a sampled
NRZ (Non Re u n o Ze o) coded signal de ined by a sequence
o bi s a i s inpu . The signal is edi ed by Gaussian il e
ha ans o ms elec ical inpu pulses in o smoo he ou pu
pulses. In ou ansmi e we use Mach-Zehnde modula o
which modula es signal om gene a o o he DFB lase . O he
blocks in Fig. 2 a e o p ope unc ion o he simula ion.
Fig. 2. T ansmi ing pa o he DWDM sys em in VPIpho onics.
A ecei ing pa o he sys em consis s o wo ypes o
il e s, Lo en zian and Bessel (op ical and elec ical). These
ypes o he il e s a e con igu ed by ecei ing wa eleng h. Ou
simula ion ocuses on unc ion o DWDM sys em, we do no
conside o wa ch he BER o senso sys em. In ou simula ion
we use DMUX 4 which has ex ension a io abou 20 dB. We
wan o simula e eal pa ame e s o he bo h sys ems (DWDM
and φ–OTDR ). A ecei ing pa o he DWDM sys em can
be seen in Fig. 3
Fig. 3. Recei ing pa o he DWDM sys em in VPI pho onics.
V. SIMULATION
We s a a –30 dBm powe o senso ic sys em and wa ch
he BER o each channel o DWDM sys em which un a
10 Gbi /s. In ou simula ion we ha e ou channels DWDM.
DWDM sys em is shi ed om senso ic sys em abou 1 nm. In
his case he BER o all channels a e abou 1E−40 and eyes
o he decision a e clea . When we g adually inc ease powe o
he senso ic lase , we can see in all g aphs ha he BER slowly
dec eases and eye o he decisions is no clea . I inc eases i
he senso ic lase has he powe a ound 0 dBm. Wi h high
powe o he senso ic lase (abou 13 dBm) DWDM is no
able o ans e da a (1E−7). Tha means da a ansmission is
unsuccess ul. In schema ic Fig. 4 we can see he simula ion
se up in VPI pho onics which is desc ibed ea lie .
Fig. 4. Lase and DWDM sys em con igu a ion in VPIpho onics.
The i s esul s o ou simula ions a e shown in Fig. 5.
I shows he in luence o he senso ic sys em o DWDM
sys em shi ed o 1 nm. Wa eleng h o he DWDM sys em is
1551.6 nm which is he hi d channel o DWDM sys em. We
s a wi h BER 1E−40 and inc ease he powe o senso ic
sys em. Dependence shows ha he BER o he hi d channel
DWDM sys em g adually dec eases wi h inc easing powe . All
g aphs also include he cu e ha shows BER limi o DWDM
sys em.
192
JOURNAL OF COMMUNICATIONS SOFTWARE AND SYSTEMS, VOL. 12, NO. 4, DECEMBER 2016
10−210−1
10−7
102
1011
1020
1029
1038
BER limi
(W)
–BER(—)
1553.4 nm
1552.4 nm
Fig. 5. In luence o he φ–OTDR o he DWDM sys em (1551.6 nm).
Fig. 6 depic s he dependency o high powe senso sys em
(abou 27 dBm) o DWDM sys em. Dis ance be ween da a
sys em and senso ic sys em is 0.5 nm.
10−210−1
10−3
104
1011
1018
1025
1032
BER limi
(W)
BER (-)
1550.5 nm
1551 nm
Fig. 6. In luence o he high powe φ–OTDR o he DWDM sys em.
Ano he impo an pa o he measu emen s is a di e ence
be ween wa eleng h spacing DWDM and φ–OTDR ha can be
seen in Fig. 7. I we ha e small spacing, in luence o φ–OTDR
sys em on he i s channel o DWDM sys em is highe han
a dis ance o mo e han 2.5 nm, when sys em is no a ec ed.
Ou designed model also includes he non-linea and linea
e ec s. Dis ance be ween da a sys em and senso ic sys em is
a iable. We ocus on dis ance by 0.5 nm, 1 nm, 1.5 nm, 2 nm,
2.5 nm.
10−210−1
10−12
108
1028
1048
1068
1088
BER limi
(W)
–BER (—)
1550.5 nm
1551 nm
1551.5 nm
1552 nm
1552.5 nm
Fig. 7. In luence o he φ–OTDR o he DWDM sys em wi h a iable dis ance.
VI. CONCLUSION
Ou simula ion sys em designed in he VPI pho onics so -
wa e showed ha i is possible o use an op ical ibe o
DWDM ansmission and i can be also used as an op ical
senso . This da a ansmission sys em is limi ed by maximum
op ical powe o he used lase o he senso sys em. Ou sim-
ula ion shows ha DWDM can ansmi da a i he powe o
φ–OTDR is unde 13 dBm. I was also e i ied ha a dis ance
o 2.5 nm i is no possible o a ec DWDM sys em wi h φ–
OTDR. Fu u e wo k aims o use ano he pulse gene a o wi h
di e en ange o pulse. These gene a o can make pulses om
10 ns o 1000 ns wi h di e en epe i ion a e o he pulses. The
mos impo an u u e wo k is measu emen in he unc ion o
DWDM sys em. This measu emen con i ms o disapp o es
ou simula ions.
REFERENCES
[1] T. Zhu, Q. He, X. Xiao, X. Bao, Modula ed pulses based dis ibu ed
ib a ion sensing wi h high equency esponse and spa ial esolu ion,
Op ics Exp ess, ol. 21, no 3, pp. 29–53. 2013.
[2] Y. Muanenda, C. O on, S. Fa alli, F. D. Pasquale, A Cos -E ec i e
Dis ibu ed Acous ic Senso Using a Comme cial O - he-Shel DFB
Lase and Di ec De ec ion Phase–OTDR, IEEE Pho onics Jou nal, ol. 8,
no. 1, pp. 1–10, 2016.
[3] S. Huang, W. Lin, M. Tsai, M. Chen, Fibe op ic in-line dis ibu ed senso
o de ec ion and localiza ion o he pipeline leaks, Senso s and Ac ua o s,
ol. 135, no 2, pp. 570–579. 2006.
[4] Y. Shi, H. Feng, Dis ibu ed ibe sensing sys em wi h wide equency
esponse and accu a e loca ion, IEEE Senso s Jou nal, ol. 77, no. 3,
pp. 219–224. Augus 2015.
[5] P. Muns e , J. Voj ech, P. Sysel, R. Si a, V. No o ny, T. Ho a h, S. Sima,
M. Filka, φ–OTDR signal ampli ica ion, Op ical Senso s, ol. 9506,
pp. 950606-1, 2015.
[6] R. Si a, P. Muns e , P. Sysel, T. Ho a h, V. No o ny, O. K ajsa, M. Filka.
Dis ibu ed Fibe -Op ic Senso o De ec ion and Localiza ion o Acous ic
Vib a ions, Me ology and Measu emen Sys ems, ol. 22, no. 1, 2015
[7] T-REC-G.694.1–201202. SERIES G: TRANSMISSION SYSTEMS AND
MEDIA, DIGITAL SYSTEMS AND NETWORKS: T ansmission media and
op ical sys ems cha ac e is ics Cha ac e is ics o op ical sys ems. 2. ed.
Swi ze land: ITU, 2012. h ps://www.i u.in / ec/T-REC-G.694.1–201202-
I/en
M. CUCKA e al.: TRANSMISSION OF HIGH POWER SENSOR SYSTEM AND DWDM DATA SYSTEM
193
[8] K. N. Choi, J. C. Jua ez, H. F. Taylo , and E. M. Ca apezza, Dis ibu ed
ibe op ic p essu e/seismic senso o low-cos moni o ing o long
pe ime e s, Una ended g ound senso echnologies and applica ions, ol.
c2003, no. 5090, pp. 134–141, 2003.
[9] R. Si a, P. Muns e , P. Sysel, T. Ho a h, V. No o ny, O. K ajsa, and M.
Filka, Dis ibu ed Fibe -Op ic Senso o De ec ion and Localiza ion o
Acous ic Vib a ions, Me ology and Measu emen Sys ems, ol. 22, no.
1, 2015.
[10] Q. Sun, H. Feng, X. Yan, and Z. Zeng, Recogni ion o a Phase-
Sensi i i y OTDR Sensing Sys em Based on Mo phologic Fea u e Ex-
ac ion, Senso s, ol. 15, no. 7, pp. 15179–15197, 2015.
[11] P. Muns e , J. Voj ech, P. Sysel, R. Si a, V. No o ny, T. Ho a h, S. Sima,
and M. Filka, -OTDR signal ampli ica ion, Op ical senso s, ol. 2015, no.
9506, p. 950606, 2015.
[12] Q. Li, C. Zhang, and C. Li, Fibe -op ic dis ibu ed senso based on
phase-sensi i e OTDR and wa ele packe ans o m o mul iple dis u -
bances loca ion, Op ik - In e na ional Jou nal o Ligh and Elec on
Op ics, ol. 125, no. 24, pp. 7235–7238, 2014.
[13] Q. Li, C. Zhang, L. Li, and X. Zhong, Localiza ion mechanisms and
loca ion me hods o he dis u bance senso based on phase-sensi i e
OTDR, Op ik - In e na ional Jou nal o Ligh and Elec on Op ics,
ol. 125, no. 9, pp. 2099–2103, 2014.
[14] Z. Pan, K. Liang, Q. Ye, H. Cai, R. Qu, Z. Fang, and J. Popp, Phase-
sensi i e OTDR sys em based on digi al cohe en de ec ion, Op ical
senso s and biopho onics III, ol. 2011, no. 8311, p. 83110, 2011.
[15] Y. Zhan, Q. Yu, K. Wang, F. Yang, Y. Kong, and X. Zhao. ”A high
pe o mance dis ibu ed senso sys em wi h mul i-in usions simul aneous
de ec ion capabili y based on phase sensi i e OTDR,” Op o-Elec onics
Re iew, ol. 23, issue 3, 2015.
[16] Y. Lu, T. Zhu, X. Bao, L. Chen, W. J. Bock, and J. Albe , Vib a ion
moni o ing wi h high equency esponse based on cohe en phase-
sensi i e OTDR me hod, 21s In e na ional Con e ence on Op ical Fibe
Senso s, ol. 2011, no. 7753, p. 77533K–77533K–4, 2011.
Milan Cucka (MSc.) was bo n in Vysko , Czech
Republic on Janua y 20, 1989. He ecei ed his
M.Sc. deg ees in Telecommunica ions om he B no
Uni e si y o Technology, B no, in 2014. His e-
sea ch in e es s include dis ibu ed op ical senso s,
op oelec onics, and ibe b agg g a ings. Cu en ly,
he has been pos g adua e s uden a B no Uni e si y
o Technology, Depa men o Telecommunica ions
and his opic o disse a ion hesis is dis ibu ed ibe
op ics sys ems.
Pe Muns e (MSc., Ph.D) was bo n in Zlin,
Czech Republic. In 2010 he g adua ed om he B no
Uni e si y o Technology and ecei ed his academic
i le o elec ical enginee (Ing.). His esea ch wo k
ocuses on op ical communica ions, especially FTTx
access ne wo ks and OTDM sys ems, and be op ic
senso s. He is an au ho o co-au ho o mo e han
wen y publica ions in scien ic jou nals and a in e -
na ional con e ences. He is a membe o p og am
commi ees o se e al con e ences.
Lukas Koci (MSc.) was bo n on 29 Sep embe 1990
in B no, Czech Republic. He g adua ed om he
B no Uni e si y o Technology and ecei ed aca-
demic i le Ing a he Depa men o Telecommuni-
ca ions. Cu en ly, he is s udying Doc o al p og am
a he B no Uni e si y o Technology, Depa men o
Telecommunica ions. His esea ch ocuses on op ical
communica ion ne wo ks, op ical ime di ision mul-
iplexing, wa eleng h di ision mul iplexing, passi e
op ical ne wo ks, and especially so wa e de ined
op ical ne wo ks.
Tomas Ho a h (MSc.) was bo n in Ha i o , Czech
Republic on Ma ch 7, 1989. He ecei ed his M.Sc.
deg ees in Telecommunica ions om he B no Uni-
e si y o Technology, B no, in 2013. His esea ch
in e es s include passi e op ical ne wo ks (xPON),
op oelec onics, and Bi To en p o ocol. Cu en ly,
he has been pos g adua e s uden a he B no
Uni e si y o Technology, Depa men o Telecom-
munica ions and his opic o disse a ion hesis is
Op imiza ion se ices in FTTx op ical access ne -
wo ks.
Milosla Filka p o . was bo n in 1946 in B no,
Czech Republic. Since 2010 he has been a p o-
esso a he Depa men o Telecommunica ions a
he B no Uni e si y o Technology. He is a leade
o he op ical g oup Op oLab and also a head o
he Labo a o y o ansmission media and op ical
ne wo ks. He is a membe o a se e al ins i u es (e.g.
Ins i u e o Elec ical Elec onics Enginee es) and is
also a commi ee o many con e ences (In e na ional
Con e ency Telecommunica ions and Signal P o-
cessing, In e na ional Con e ency New In o ma ion
and Mul imedia Technologies). His cu en esea ch hemes ocus on ibe -
op ic elecommunica ions, especially FTTx echnologies.
Jose Voj ech (MSc., B.Sc., Ph.D) ecei ed wi h
hono s M.SC. deg ee in Compu e Science, B.Sc.
deg ee in Pedagogy and Ph.D. in ield o op ical
ne wo king om he Czech Technical Uni e si y,
P ague, in 2001, 2003 and 2009 espec i ely. Since
2003, he has been wi h esea ch Depa men o
Op ical Ne wo ks, CESNET, a.l.e., which he leads
now. He pa icipa ed in in e na ional p ojec s: COM-
PLETE, FI-PPP XIFI, GN4, GN3+, GN3, GN2,
Po a Op ica S udy, SEEFIRE. He has been also
esponsible o de elopmen o open amily o pho-
onic de ices. He holds 15 pa en s (including 3 US and 1EU) and u ili y
models. His eco d shows Hi sch index 5 wi h mo e han 64 ci a ions. He is
a membe o IEEE, OSA and SPIE. In 2007 he ecei ed he Resea ch p ize
o he Czech minis e o educa ion.
194
JOURNAL OF COMMUNICATIONS SOFTWARE AND SYSTEMS, VOL. 12, NO. 4, DECEMBER 2016