Design of time division multiplexing/wavelength division multiplexing passive optical network system for high-capacity network

International Journal of Electrical and Computer Engineering (IJECE)
Vol. 13, No. 4, August 2023, pp. 4152~4158
ISSN: 2088-8708, DOI: 10.11591/ijece.v13i4.pp4152-4158  4152
Journal homepage: http://ijece.iaescore.com
Design of time division multiplexing/wavelength division
multiplexing passive optical network system for high-capacity
network
Farid Hazwan Azmi1
, Nani Fadzlina Naim1
, Norsuzila Ya’acob1
, Suzi Seroja Sarnin1
,
Latifah Sarah Supian2
1
School of Electrical Engineering, College of Engineering, Universiti Teknologi MARA (UiTM), Selangor, Malaysia
2
Fakulti Kejuruteraan, Universiti Pertahanan Nasional Malaysia, Kuala Lumpur, Malaysia
Article Info ABSTRACT
Article history:
Received Jun 17, 2022
Revised Sep 28, 2022
Accepted Oct 1, 2022
This paper presents the design of time division multiplexing-wavelength division
multiplexing-passive optical network (TDM-WDM PON). In this design, the
current TDM PON is incorporated with the proposed WDM-PON in order to
design a high-capacity network with lower loss requirements. The design has
been simulated using OptiSystem software. The upstream wavelength for
WDM is between 1,530.334 to 1,542.142 nm while for TDM is 1,310 nm.
The downstream wavelength for WDM is from 1,569.865 to 1,581.973 nm,
while for TDM is 1,490 nm. Based on the result, it is found that the
proposed network is capable to support up to 64 customers with a bit rate of
2.5 Gbps.
Keywords:
High capacity
Passive optical network
Simulation
Time division multiplexing
Wavelength division
multiplexing
This is an open access article under the CC BY-SA license.
Corresponding Author:
Nani Fadzlina Naim
School of Electrical Engineering, College of Engineering, Universiti Teknologi MARA (UiTM)
40450 Shah Alam, Selangor, Malaysia
Email: nanifadzlina@uitm.edu.my
1. INTRODUCTION
It is acknowledged that wavelength division multiplexing–passive optical network (WDM–PON) is
one of the most promising technology. This technology is suitable for broadband access network deployment
due to its flexibility and capability of the optical network to carry high bandwidth. Recently, transmission in
the wavelength domain has been applied for ethernet or gigabit-PON (E/G-PON) technology. Urban et al. [1]
conducted the combination or hybridization of these technologies for a more cost-effective implementation.
Figure 1 shows the WDM-PON technology implementation in E/G PON. The basic components available are
such as the optical line terminal (OLT), the PON network, and the optical network unit (ONU). A passive
multiplexer and demultiplexer module are applied in the network to accommodate multiple wavelengths
transmitted between the OLT and the ONU. Thus, more advantages will be added to the system such as
enhancing security with the ability to allocate a desired wavelength to each user, economical implementation
since a similar optical network could be utilized, and scalability in distance, speed, and dimension [2].
A C-band WDM–PON prototype [3] is demonstrated to provide 20 Gb/s downstream and 20 Gb/s
upstream bandwidth. This prototype system has a minimum loss budget of 21.3 dB and supports a connection
distance of 40 km with a split ratio of 1:8. Performance analysis of time division multiplexing (TDM) and WDM–
PON has been conducted [4] using OptiSystem software for multiple access networks. Basically, TDM–PON
provides a high number of channels with moderate bandwidth using a single wavelength. On the other hand,
WDM-PON uses multiple wavelengths to enhance the capacity without increasing the data rate in a single fiber.

Int J Elec & Comp Eng ISSN: 2088-8708 
Design of time division multiplexing/wavelength division multiplexing … (Farid Hazwan Azmi)
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Figure 1. Generic WDM–PON architecture [1]
Li et al. [5] proposed a hybrid TDM/WDM-PON architecture compatible with the traditional TDM-
PON conﬁguration using a power splitter in the remote node. To select the downstream wavelength of each
optical network unit, they use a tunable optical filter (TOF). Meanwhile, by seeding a reflective
semiconductor optical amplifier (RSOA) to build a tunable fiber ring, the TOF plays a second role as a
colorless upstream source. For the upstream laser source tuned from 1,535 to 1,565 nm, a good output is
defined with a modulation data rate of 1.25 Gbps. The upstream wavelength has a 0.1 nm offset with the
TOF's central wavelength when the RSOA is skewed in its saturation area, minimizing the Rayleigh
backscattering and the reflective back crosstalk in single-fiber bidirectional PON systems.
Manaf et al. [6] proposed the upstream characteristics of tunable WDM-PON system. They decided
to use a tunable ONU transceivers and tunable OLT as both transmitter and receiver of the system. As for the
existing PON structure, they decided to add WDM infrastructure in one design to form a WDM-PON system.
A 16-channel wavelength plan is applied in their architecture. They also introduce the usage of arrayed
waveguide grating (AWG) in their system. The results show that distance can affect the power received and
the laser signal performance at the ONU. Bit error rate (BER) shows that the further the distance, the higher
the BER. BER is the ratio of the number of erroneous bits received to the total transmitted bits [7]. In other
words, high BER means that the receiver is receiving a high number of error bits as compared to the low
BER. This can be an indicator of the condition of the transmission link or system.
Implementing an economic broadband access network is genuinely flexible in scope that will
require substantial technological changes. Operating basically passive fiber connections from the client to
central offices, which could be between 100 and 150 km away, could lead to significant cost and energy
savings [8]. The simplest structure for each connection is precisely point-to-point, with a physical fiber. This
selection was chosen for a range of fiber-to-the-home (FTTH) deployments, for example in Sweden and the
Netherlands [9], [10]. Such a solution is competitive where there is no unreasonable cost of fiber deployment
and where the accumulation point is relatively close to the user. More typically, a 'virtual point-to-point'
system is preferable in the case of 'long-reach' access systems. WDM is the key to reducing the required
hardware, hence the existence of a WDM-PON [11], either by combining WDM with TDM, these systems
can provide the desired economically advantageous long-range service [12] or by allocating each user a full
wavelength channel [13]. In order to be economically viable, it is crucial that terminals are all identical in a
WDM network, i.e., 'colorless' – inventory management and deployment problems will otherwise dominate
installation costs. Many solutions have been proposed to this problem, including injection-locked laser
systems on the user site [14] and on reflective modulation [15]. Such systems, which are indeed successful,
present major challenges that restrict the efficiency and cost-effectiveness of the overall system. Generally
speaking, there has been an observation in the industry that solutions focused on tunable laser technology
will be expensive for widespread implementation in home terminals.
It is acknowledged that the most widely used multiplexing techniques are TDM and WDM [16].
NG-PON1 may suffer bandwidth restrictions in the future as the network capacity is decreasing very rapidly
[17]. TDM PON has its limitations whereas a single wavelength is allocated for the upstream and
downstream, thus this will limit the average bandwidth per user and the bandwidth of a single fiber. A high
splitting ratio in TDM PON will also limit the fiber reach for up to around 20 km for a 32 split and a 28 dB
link budget. Therefore, by combining TDM and WDM-PON can overcome this problem. CWDM technology
is deployed upstream and DWDM is deployed downstream [18]. In [19], hybrid TDM–WDM PON and
stacked TDM-PON are designed and analyzed to support NG-PON2. The performance of TDM-WDM PON
is mainly dependent on the architecture [20]. Kumar and Randhawa [21] improved TDM-WDM PON has

 ISSN: 2088-8708
Int J Elec & Comp Eng, Vol. 13, No. 4, August 2023: 4152-4158
4154
been designed with various modulation techniques at the WDM transmitter to improve the performance.
Several WDM-PONs performances including hybrid TDM-WDM PON have also been analyzed in [22]. In
[23], the hybrid TDM/WDM PON has been designed and analyzed with a bidirectional semiconductor
optical amplifier (SOA). Basically, the main objectives of NG-PON are to increase the data rate for the
customer and to extend the fiber reach to the customer for cost efficiency [24].
The idea comes as the number of users is increasing. The current TDM-PON design does not
support much bandwidth. This supports very powerful user-shared bandwidth, but it requires each ONT to
run at a full line speed of 40 Gbps, a rate that far exceeds individual users' needs. The current TDM-PON
system design requires a high cost. Full-service access network (FSAN) has discontinued TDM-PON due to
high costs and uncertainty associated with certain challenges, such as solving the problem of chromatic
dispersion at very high line rates. Hence, WDM-PON will be added to the system design, with tunable 16-
channel OLT, where it can handle a greater bandwidth and a high-capacity network.
Thus, this paper is proposed to support a larger bandwidth and handle a great number of users in one
system design at a lower loss. It is proven that WDM can increase the capacity of the existing FTTH
network, thus it will be added alongside TDM. Moreover, this paper will introduce a design with a higher
capability to handle high traffic. Both TDM and WDM designs will be combined to form an economic
network with high capacity. It is simulated using OptiSystem software which is well-known for its capability
to simulate almost all types of optical links [25].
2. METHOD
This TDM WDM-PON is designed and simulated using OptiSystem software. The current
wavelength for the current FTTH technology, which employs TDM-PON, is 1,490 nm for downstream and
1,310 nm upstream. For the WDM-PON system, a new wavelength plan is proposed. The selected
wavelength is based on the C and L band's 100 GHz spacing. The C-band is used for upstream signals
between 1,530.334 and 1,542.142 nm, while the L-band is used for downstream signals between 1,569.865
and 1,581.973 nm. That value was selected because the current 10G/G/EPON network does not conflict with
it.
The proposed design of TDM WDM-PON is shown in Figure 2. The WDM-PON system is
integrated into this concept and its components are represented by the orange-colored blocks in Figure 2.
Next, the WDM multiplexer and demultiplexer are applied based on the wavelength plan. The function of the
WDM multiplexer and demultiplexer is to multiplex and route the downstream wavelengths from the OLT,
and to demultiplex the designated subscribers. Meanwhile, for upstream signals, another multiplexer and
demultiplexer will multiplex the signals from the ONUs and route them back to the OLT. In this case, each
port is defined with wavelengths for downstream and upstream signals, respectively. It is decided that the
transmitter will be set at 5 dBm for both upstream and downstream fiber laser at both OLT and ONU.
Figure 2. Proposed sharing concept with existing PON infrastructure

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Next, the proposed design is modeled using the OptiSystem simulation for verification. Figure 2
shows the proposed sharing concept of TDM WDM-PON. In this design, the existing TDM-PON is
combined with WDM-PON. At the central office, the existing OLT is integrated with TDM and WDM
standards. The TDM downstream signal of 1,490 nm is multiplexed with WDM downstream signals ranging
from 1,569.865 to 1,581.973 nm. The downstream signals will pass through the feeder fiber with a fiber
length of 10 km. For TDM PON, a 1×4 power splitter will split the downstream signal to a 1×16 splitter
before it reaches the ONU. In the existing network, a 1×8 or 1×16 is used for TDM-PON. By employing the
WDM concept in this network, a demultiplexer of 1×8 or 1×16 will be used to replace the use of a power
splitter. Employing a demultiplexer in the network will reduce the total loss as a demultiplexer has lower
insertion loss as compared to a power splitter. The maximum length for this network is fixed at 20 km.
3. RESULTS AND DISCUSSION
In this part, a detailed analysis of the simulated design is conducted. For 32 users, it can be seen in
Figure 3 that the laser signals are received and traveled through a multiplexer, splitter, and demultiplexer.
The signal successfully arrived at the OLT. The same goes for a downstream architecture where the laser
signals successfully reach ONU as in Figure 4.
Figure 3. Upstream signal at OLT with 1,310 nm
for TDM and 1,530.334 to 1,536.088 nm for WDM
Figure 4. Downstream signal at ONU with 1,490 nm
for TDM and 1,569.865 to 1,575.619 nm for WDM
As displayed in Figure 5, for 8 wavelength channels, the power received at ONU for both WDM and
TDM are -4.3700277 dBm and -18.862161 dBm, respectively. Meanwhile, for OLT, both WDM and TDM
received a power of -8.0446148 dBm and -18.643456 dBm. As for 16 wavelength channels, the power
received at ONU for both WDM and TDM is -4.3700318 dBm and -22.249513 dBm. Meanwhile, for OLT,
both WDM and TDM received a power of -8.0446148 dBm and -21.653756 dBm. As the number of channels
increased, the received power at each OLT and ONU terminals decreased due to higher losses mostly
produced by the splitter, especially for TDM PON.
As depicted in Figure 5, the received power for downstream signals decreases as the number of
ONUs increases. The splitter causes the loss as it splits into more channels to deliver the signal.
Theoretically, the higher the splitting ratio of the splitter, the higher the insertion loss. Basically, this network
is able to support up to 64 ONUs and the power received is -27.2 dBm which is higher than the ONU
sensitivity which is -28 dBm for TDM PON. For WDM-PON, it is found that the power received at the ONU
is almost constant as it uses a mux/demultiplexer to replace the optical splitter. Thus, by incorporating
WDM-PON into TDM PON, the constraints due to optical losses are not the issue.
Figure 6 shows the power received from upstream signals for TDM and WDM-PON. Again, the
power received for TDM PON is decreased due to the losses mainly from the optical splitter. However, for
WDM-PON, a very slight loss is suffered only due to the optical fiber loss which is 0.2 dB/km. The OLT
sensitivity for TDM PON is -28 dBm. Thus, this network is capable to be used for up to 64 ONUs as the
power received for 64 ONUs is only -24.8 dBm.

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Figure 5. Graph of downstream received power at ONU versus number of ONU
Figure 6. Graph of upstream received power at OLT
Figure 7 shows the power received from the downstream and upstream signals for various numbers
of ONUs. It can be clearly perceived that the power decrease is very low at WDM-PON as it uses a
mux/demultiplexer which will produce a very low loss. In contrast to TDM-PON, it uses an optical splitter
which will produce higher losses as compared to mux/demultiplexer.
Figure 7. Graph of downstream and upstream received power for WDM-PON at ONU and OLT

4157
4. CONCLUSION
In conclusion, this project has successfully demonstrated the design of TDM WDM-PON which can
be implemented for the current use of PONs. The design has been simulated using OptiSystem software and
the result has been analyzed. It is found that the integration of TDM and WDM-PON can support up to 64
customers with a bit rate of 2.5 Gbps.
ACKNOWLEDGMENT
The author wishes to thank Universiti Teknologi MARA (UiTM) under internal research grant
600- RMC/GPK 5/3 (101/2020) for supporting this project.
REFERENCES
[1] P. J. Urban et al., “High-bit-rate dynamically reconfigurable WDM–TDM access network,” Journal of Optical Communications
and Networking, vol. 1, no. 2, p. A143, Jul. 2009, doi: 10.1364/JOCN.1.00A143.
[2] Cedric Lam, Passive optical networks - principles and practice. Burlington, MA, Academic Press, 2007.
[3] V. Kachhatiya and S. Prince, “Conventional band (c-band) wavelength division multiplexed passive optical network (WDM-
PON),” in 2014 International Conference on Communication and Signal Processing, Apr. 2014, pp. 377–381, doi:
10.1109/ICCSP.2014.6949866.
[4] R. Sharma, M. Pathak, and A. K. Gupta, “Performance analysis of TDM-PON and WDM-PON,” in Sharma Raju Pathak Monika
Gupta Anuj Kumar, Springer, 2022, pp. 243--253.
[5] Z. Li, L. Yi, Y. Zhang, Y. Dong, S. Xiao, and W. Hu, “Compatible TDM/WDM PON using a single tunable optical filter for both
downstream wavelength selection and upstream wavelength generation,” IEEE Photonics Technology Letters, vol. 24, no. 10,
pp. 797–799, May 2012, doi: 10.1109/LPT.2012.2186435.
[6] Z. A. Manaf, A. Ahmad, Z. A. Kadir, U. S. Ismail, M. S. Salleh, and Z. M. Yusof, “Upstream characteristics of tunable WDM-
PON system for deployment in Malaysia,” in 2012 IEEE 3rd International Conference on Photonics, Oct. 2012, pp. 51–55, doi:
10.1109/ICP.2012.6379885.
[7] Bob Chomcyz, Planning fiber optic networks. McGraw Hill, 2009.
[8] Davey Russell P et al., “Long-reach passive optical networks,” Journal of Lightwave Technology, vol. 27, no. 3, pp. 273–291,
2009.
[9] C. P. Larsen, “Access network technologies: deployments in Sweden,” in 33rd European Conference and Exhibition on Optical
Communication - ECOC 2007, 2007, vol. 2007, pp. 1–4, doi: 10.1049/ic:20070075.
[10] G. van den Hoven, “FTTH deployment taking off in Europe,” in 2008 5th International Conference on Broadband
Communications, Networks and Systems, Sep. 2008, pp. 221–221, doi: 10.1109/BROADNETS.2008.4769074.
[11] K. Grobe and J.-P. Elbers, “PON in adolescence: from TDMA to WDM-PON,” IEEE Communications Magazine, vol. 46, no. 1,
pp. 26–34, Jan. 2008, doi: 10.1109/MCOM.2008.4427227.
[12] G. Talli and P. D. Townsend, “Hybrid DWDM-TDM long-reach PON for next-generation optical access,” Journal of Lightwave
Technology, vol. 24, no. 7, pp. 2827–2834, Jul. 2006, doi: 10.1109/JLT.2006.875952.
[13] S.-M. Lee, S.-G. Mun, M.-H. Kim, and C.-H. Lee, “Demonstration of a long-reach DWDM-PON for consolidation of
metro and access networks,” Journal of Lightwave Technology, vol. 25, no. 1, pp. 271–276, Jan. 2007, doi:
10.1109/JLT.2006.887179.
[14] A. and others Borghesani, “Colourless operation of a reflective semiconductor optical amplifier for 2.5 Gbit/s upstream
transmission in a WDM-PON,” in 33rd European Conf. Optical Communication, Berlin, 2007, pp. 89–90.
[15] M. J. Wale, “Technology options for future WDM-PON access systems,” in 2009 14th OptoElectronics and Communications
Conference, Jul. 2009, pp. 1–2, doi: 10.1109/OECC.2009.5218125.
[16] K. S. and P. Atul, “Recent trends in WDM passive optical network for smart IoT-based applications,” in Proceedings of the
International e-Conference on Intelligent Systems and Signal Processing, 2022, pp. 331–344.
[17] E. Wong, “Next-generation broadband access networks and technologies,” Journal of Lightwave Technology, vol. 30, no. 4,
pp. 597–608, Feb. 2012, doi: 10.1109/JLT.2011.2177960.
[18] M. E. Abdalla, S. M. Idrus, and A. B. Mohammad, “Hybrid TDM-WDM 10G-PON for high scalability next generation PON,” in
2013 IEEE 8th Conference on Industrial Electronics and Applications (ICIEA), Jun. 2013, pp. 1448–1450, doi:
10.1109/ICIEA.2013.6566595.
[19] M. A. Elmagzoub, A. B. Mohammad, R. Q. Shaddad, and S. A. Al-Gailani, “Physical layer performance analysis of hybrid and
stacked TDM–WDM 40G-PON for next generation PON,” Optik, vol. 125, no. 20, pp. 6194–6197, Oct. 2014, doi:
10.1016/j.ijleo.2014.06.139.
[20] H. Bai and Y. Wang, “Tunable wavelength converters based switching structure for WDM-TDM hybrid PON,” Optik, vol. 124,
no. 22, pp. 5388–5390, Nov. 2013, doi: 10.1016/j.ijleo.2013.03.130.
[21] A. Kumar and R. Randhawa, “An improved hybrid WDM/TDM PON model with enhanced performance using different
modulation formats of WDM transmitter,” Journal of Optical Communications, vol. 42, no. 4, pp. 643–648, Oct. 2021, doi:
10.1515/joc-2018-0154.
[22] K. Grobe, M. Roppelt, A. Autenrieth, J.-P. Elbers, and M. Eiselt, “Cost and energy consumption analysis of advanced WDM-
PONs,” IEEE Communications Magazine, vol. 49, no. 2, pp. s25–s32, Feb. 2011, doi: 10.1109/MCOM.2011.5706310.
[23] A. Emsia, Q. T. Le, M. Malekizandi, D. Briggmann, I. B. Djordjevic, and F. Kuppers, “WDM–TDM NG-PON power budget
extension by utilizing SOA in the remote node,” IEEE Photonics Journal, vol. 6, no. 2, pp. 1–10, Apr. 2014, doi:
10.1109/JPHOT.2014.2314108.
[24] F. J. Effenberger, “The XG-PON system: cost effective 10 Gb/s access,” Journal of Lightwave Technology, vol. 29, no. 4,
pp. 403–409, Feb. 2011, doi: 10.1109/JLT.2010.2084989.
[25] S. A. Al-Gailani, A. B. Mohammad, and R. Q. Shaddad, “Enhancement of free space optical link in heavy rain attenuation using
multiple beam concept,” Optik, vol. 124, no. 21, pp. 4798–4801, Nov. 2013, doi: 10.1016/j.ijleo.2013.01.098.

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BIOGRAPHIES OF AUTHORS
Farid Hazwan Azmi received his Bachelor of Electronics Engineering from
Universiti Teknologi MARA (UiTM) in 2019. Currently, he is an application engineer at BPE
Synergy Engineering Sdn. Bhd. His research interests are in optical networks and wireless
communication. He can be contacted at farid96_azmi@yahoo.com.
Nani Fadzlina Naim received her B.Eng. degree in electrical and electronics
engineering and her M.Eng. degree in electronics and communication engineering from
Universiti Teknologi Malaysia, in 2005 and 2007, respectively. She holds a Ph.D. in optical
communication from Universiti Kebangsaan Malaysia (UKM) in 2015. Currently, she is a
senior lecturer at Universiti Teknologi MARA (UiTM). Her current research interests are in
the areas of optical communication, fiber Bragg grating-based sensors, optical sensing
technology, and their applications. She can be contacted at fadzlina007@hotmail.co.uk.
Norsuzila Ya’acob is an associate professor at the Department of Communication
Engineering, School of Electrical Engineering, College of Engineering, Universiti Teknologi
MARA (UiTM). In 2010, she was awarded a Ph.D. degree in electrical, electronics & systems
engineering from Universiti Kebangsaan Malaysia (UKM), Malaysia for her work on
“Modelling and Determination of Ionospheric Effects to Improve GPS System Accuracy”. She
received her M.Sc. degree from University Putra Malaysia (UPM) in remote sensing and
geographic information systems in 2000. She also obtained her B.Eng. degree from the
University of Putra Malaysia (UPM), Malaysia in electronics and computer engineering in
1999. She is the Deputy Director for UiTM Satellite Centre at the School of Electrical
Engineering UiTM. She is also a member of the Wireless Communication Technology Group
(WiCoT). Her current research interests are in the areas of satellite communication, space
weather, remote sensing and GIS, wireless communication, and signal processing. She can be
contacted at norsuzila@uitm.edu.my.
Suzi Seroja Sarnin received her Bachelor of Electrical and Electronics (B.Eng.)
in the communication field in 1999 from Universiti Teknologi Malaysia (UTM), Skudai,
Johor. She completed her Master of Microelectronics (MSc.) from Universiti Kebangsaan
Malaysia in 2005. She received her Ph.D. in Electrical engineering in 2018. Currently, she is a
senior lecturer at the Faculty of Electrical Engineering, Universiti Teknologi MARA (UiTM).
Her research interests are in wireless communication and the internet of things (IoT). She can
be contacted at suzis045@uitm.edu.my.
Latifah Sarah Supian received her B.Eng. degree in electrical and computer
engineering from Stevens Institute of Technology, New Jersey, USA, and her M.Eng. degree
in communication and computer from Universiti Kebangsaan Malaysia, Bangi, Malaysia in
2009 and 2011, respectively. From 2012 to 2015, she joined the Computer and Network
Research Group in the Faculty of Engineering, Universiti Kebangsaan Malaysia as a graduate
Ph. D student in optical communication. Currently, she works as a lecturer at Universiti
Pertahanan Nasional Malaysia (National Defence University of Malaysia). Her research
interests include polymer optical fibers technology, optical waveguides, and fiber lasers. She
can be contacted at sarah@upnm.edu.my.

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