Haidar Zaeer Dhaam*, Mohammed Jawad Al Dujaili, Mushtaq Talib Mezeel and Abdullah Ali Qasim Performance of high scalability hybrid system of 10G-TDM-OCDMA-PON based on 2D-SWZCC code https://doi.org/10.1515/joc-2021-0075 Received March 21, 2021; accepted October 12, 2021; published online November 8, 2021 Abstract: A new architecture for increasing the number of simultaneous users in a hybrid system and providing a solution for the channel bottleneck problem has been designed and simulated. The 10G-TDM-OCDMA-PON system combines optical code division multiple access (OCDMA) and time-division multiplexed passive optical network (TDM-PON) techniques. The high bit rate TDM-PON system is based on a bit interleaving that uses noncontiguous order for data arranging manner, this system used to obtain ultra-high-speed data rate of 40 Gbps based on four TDM channels of 10 Gbps. The OCDMA system is based on two-dimensional single weight zero cross-correlation (2D-SWZCC) employing polarization and wavelength scheme with two orthogonal polarization angles (vertical and horizontal states). The proposed hybrid system increases the scalability by multiplexing M OCDMA codes in the same time slot of the TDM system that has N time slots. The results show that the proposed system with 2D-SWZCC has better performance with a high number of users and higher scalability than the system with 1D-SWZCC. Keywords: hybrid PON; OCDMA; SWZCC; TDM. 1 Introduction The new and future demands of the modern customer require a high-speed connection suitable to these de- mands. Passive optical networks can be considered as a good solution for this issue providing high-speed, high- reliable, future-proof infrastructure, and cost-efficient connection [1]. The development of optical networks is important to utilize the maximum possible bandwidth of fiber optics; the different access techniques used can give a considerable improvement toward high scalable net- works. Optical code division multiple access (OCDMA) and time-division multiplexed (TDM) techniques have been considered good systems for high bandwidth net- works [2]. OCDMA system allows multiple users to access the medium asynchronously and simultaneously with higher efficiency, flexibility, security, and easier network control at a relatively low cost [3, 4]. In the high-speed OCDMA systems, the transceiver operations may have imperfectly orthogonal signature codes [5]. This issue may cause some crosstalk between the subscribers who use the same channel. Where this crosstalk can be considered as a multiple access interference (MAI). The MAI and the source noise are the main sources of bit errors [5]. To overcome the effect of the system noises and MAI A. Cherifi et al. have proposed an OCDMA system based on two-dimensional (2D) wavelength/spatial code called 2D single weight zero cross-correlation (2D-SWZCC) which used a single weight code that has zero cross-correlation and a high number of subscribers. The results of the sys- tem simulation indicate that the 2D-SWZCC code has better performance in comparison to the other OCDMA systems which are based on 2D-FCC/MDW, 2D-PD, 2D-DCS, 2D-MD, 2D-Extended-EDW, and one-dimensional (1D)-SWZCC codes [6]. In Ref. [7], a new design that provides large capacity and security has been proposed based on a new 2D wavelength-hopping/time-spreading (WH/TS) OCDMA code. The simulation results show that this system can provide high-speed and secure transmission at the long- haul connection. In addition, the security can be improved by increasing the number of interference subscribers and *Corresponding author: Haidar Zaeer Dhaam, Department of Laser and Electro Optics Technical Engineering, Technical Engineering College\Najaf, Al-Furat Al-Awsat Technical University (ATU), Najaf, Iraq, E-mail: Haidar.dhaam@atu.edu.iq. https://orcid.org/0000-0001-6628-3830 Mohammed Jawad Al Dujaili, Department of Electronic and Communication, Faculty of Engineering, University of Kufa, Najaf, Iraq, E-mail: Mohammed.challab@uokufa.edu.iq Mushtaq Talib Mezeel, Najaf Provincial Council, Najaf, Iraq, E-mail: mshtqtlb@gmail.com Abdullah Ali Qasim, Department of Laser and Electro Optics Technical Engineering, Technical Engineering College\Najaf, Al-Furat Al-Awsat Technical University (ATU), Najaf, Iraq, E-mail: alzubydea@gmail.com J. Opt. Commun. 2021; aop