**Abstract**

This chapter discusses the extensibility of fiber to the x (FTTx) households, specifically in the territory of the European Union. The Czech Republic has made a commitment to other member states to provide connectivity of at least 100 Mbit/s for half of the households by 2020. Although Internet access in the Czech Republic is mostly dominated by wireless fidelity (WiFi), this technology is not capable of meeting the demanding current demands at a reasonable price. As a result, passive optical networks are on the rise in access networks and in mobile cell networks by fiber to the antenna (FTTA). Passive optical networks use much more complex networks. In cooperation with Orange Slovakia, the analysis of the transmitted data was conducted. The optical network unit management and control interface (OMCI) channel data, as well as the activation data associated with specific end units, were analyzed. We propose a complete analysis of the end-unit-related activation process, download, and initialization of the data image for setting the end units and voice over Internet protocol (VoIP) parameters. Finally, we performed an analysis of the transmission of dying gasp messages.

**Keywords:** dying gasp, GPONxpert, OMCI channel analysis, ONU activation process analysis, PON deployment, transmission convergence layer

## **1. Introduction**

The optical infrastructure is essential for current applications that demand a high bandwidth [1–3]. The International Telecommunication Union (ITU) has been developing standards for passive optical networks (PONs) for over 20 years [4, 5]. The second most active organization in this area is the Institute of Electrical and Electronics Engineers (IEEE) [6, 7].

Passive optical networks are currently expanding, as the European Union (EU) has allocated budget to extend the coverage of these networks [8]. Today, the access network is not only about transferring data streams from/to the Internet. The popularity of Amazon TV, Netflix, and so on puts increased demands on bandwidth. Current transmission speeds are not sufficient, and a bandwidth of at least 100 Mbit/s in every household is still under consideration. In the Czech Republic, the utilization of gigabit PON (GPON) standard still dominates. However, such standard was in its first version approved back in 2003 [9]. This standard makes it possible to achieve a bandwidth of up to 2.5 Gbit/s in full duplex mode, but the disadvantage is that the bandwidth is fully shared by

all end users (in theory, up to 128 customers per port). The available bandwidth can be operatively changed in time and according to the requirements using dynamic bandwidth allocation (DBA) algorithms [10–13]. The decreasing cost of the necessary devices allows GPON optical line termination (OLT) to be used more often for service providers; on the other hand, the standard in use may not be sufficient for the future. The cost of the next-generation PON (XG-PON) terminal units is still quite high, regardless of the OLT unit price. The price of the technology itself is determined by the price of the optical network unit (ONU) terminal units. The advantage of deploying next-generation networks would be the ability to a share the transfer rate of up to 10 Gbit/s. Together with appropriate DBA algorithms, the full bandwidth utilization or its adequate distribution between endpoints would be efficiently used. GPON networks theoretically allow us to transfer data up to 19 Mbit/s for each ONU (considered for the maximum transfer rate and a split ratio of 1:128). XG-PON networks are limited by higher split ratios but have higher transfer rates available. Theoretically, 39 Mbit/s can be achieved for each ONU. In other words, the transfer rates are the maximum possible in both GPON and XG-PON networks. Usually, the guaranteed transfer rates are several times lower according to the use of a transmission container (T-CONT) [14].
