Evolution of PON standards

XG-PON / XGS-PON technologies and their features

XG-PON (10G-PON) is an updated passive fibre optic networking standard that enables the exchange of large amounts of data in seconds and provides multiple devices with the Internet at theoretical speeds of up to 10 Gbps.

XGS-PON is the technological evolution of XG-PON, which is a symmetrical passive optical access network with a theoretical capacity of 10 Gbps. "Symmetrical" means that this standard provides the same downstream and uplink speeds. Also, XGS-PON technology allows the simultaneous use of multiple wavelengths, resulting in increased network capacity and flexibility.

Next, let's look at the features of the four major PON standards: EPON (Ethernet PON), GPON (Gigabit PON), XG-PON (10 Gigabit PON) and XGS-PON (symmetric XG-PON). Each of these uses a different wavelength range. As they evolve, they attempt to maintain compatibility with previous standards by utilising free zones in the light spectrum (i.e. wavelengths not used in previous standards).

As can be seen from the table, the downlinks of all the standards under consideration share a common wavelength band (from 1260 to 1280 nm). This is because GPON was not able to use this frequency band, despite having reserved it. Therefore, there is an opportunity for XG-GPON and XGS-PON to benefit from this small unused frequency band.

EPON in downstream upstream streams reaches 1.25 Gbps, GPON in downstream — up to 2.488 Gbps. The value of outbound flows is approaching the speed of 1.244 Gbps. In addition, the evolution of development can be seen in the topology of network construction. The structure of a passive EPON-network is a branching of 1x64 trees, the radius reaches 30 km. While for GPON — it is 1x128, and the radius reaches 60 km.

GPON already uses linear bilevel coding (NRZ), which is a primitive bipolar coding method that guarantees the lowest bandwidth reduction with minimal loss of speed. That is why the ETB (effectively transmitted bandwidth) for GPON is rarely less than 95%, and in the case of EPON this efficiency is closer to 70%. XG(S)PON as a more developed standard inherits the advantages of GPON.

It is also worth adding that the GPON system can evolve directly to NG-PON2, a next-generation passive optical network with 40Gbps capacity. Depending on service and network development, this mode skips the XG-PON phase and directly upgrades GPON to NG-PON2. The technology is mainly designed for business users: large companies, industrial enterprises, 5G mobile telephony.

Maxnet is the first provider in Kharkiv, which implements XG-PON and XGS-PON technologies for connection of Internet services. When connecting this technology, we offer modern optical terminals that work on the standard XG-PON, while having support for dual-band Wi-Fi 6, gigabit and USB-ports, as well as a port for connecting a telephone set to SIP-telephony. Thus, it is a universal solution, on the platform of which you can use a set of services.

And for the B2B segment we offer XGS-PON STICK ONU SFP+, specially designed for passive optical networks with a bandwidth of 10 Gbit/s (XGS-PON).

Who needs XG-PON and XGS-PON standards and what for

Fibre optic Internet connected by XG-PON or XGS-PON technology is designed for smooth operation of any corporate areas:

• Business (offices and enterprises).
• Medical industry.
• Financial and educational institutions.
• Facilities in the hospitality industry.
• Shopping centres.

The new data transmission standards may also be useful for:

• High-definition digital television.
• Network storage.
• Smart home systems.
• Cloud computing.
• Gaming and cybersports.
• AR/VR technologies.

If you are a content creator, developer or user who needs to work with large amounts of data, XG-PON and XGS-PON technologies are also for you.

With ultra-wide bandwidth, the XG-PON and XGS-PON standard allows you to optimise processes, increase overall efficiency and significantly reduce latency. For home users, XG-PON and XGS-PON help with tasks such as:

• Quickly downloading content.
• Comfortable viewing of 4K/8K streaming videos.
• Remote working and online video conferencing in high resolution.
• Collaborative cloud computing.
• Immersive virtual reality (VR) and augmented reality (AR) technologies.

Advantages of XG-PON and XGS-PON technologies for users

The key advantages of the new XG-PON and XGS-PON standards over broadband technology are:

1. Fault tolerance.
2. Energy independence.
3. Increased data transmission speed.
4. Reduced signal delay (minimal ping).
5. Increased security of data transmission.
6. Increased reliability.
7. Ability to use modern technologies (e.g. VR/AR, artificial intelligence, XR content streaming, 8K video viewing).
8. Possibility of teleconferencing.
9. Organisation of a comfortable remote workplace.

Conclusions

It is very likely that in a few years' time, XGS-PON will be the main technology that will provide users with access to high-speed Internet. All thanks to the versatility of XG-PON devices, which can work together with XGS-PON, as well as the currently observed decrease in the cost of optical subscriber terminals (ONT). Therefore, connecting the Internet on the basis of the updated standards is already the right decision today.