Miloslav Hula

Photonic services, their enablers and applications

The paper introduces photonic service as a new type of multi-domain, end-to-end network service, that besides traditional data transmission enables also non-data or real-time communication, e.g. the remote control and sharing of different, typically unique, devices. We proved the concept of photonic services on a specialized metrology application - comparison of time scales, where time offset between atomic clock is measured. The experiment has been conducted over distance of 550 km (342 miles).

Interference of Data Transmission in Access and Backbone Networks by High-Power Sensor System

ABSTRACT Currently, individual optical fibers are mostly used for each non-data application, which is very inefficient and uneconomical. Sharing a single fiber for multiple applications is a promising solution. However, in the case of a non-data application, the situation is much more complicated compared to data because of special application´s requirements. In laboratory setup, we performed a measurement with a standard G.652D optical fiber for analyzing possible interaction of stable frequency/accurate time transmission, 1.25/10Gbps data transmission (typical bitrates for access point-to-point networks), and high-power sensor signal for different channel spacing and different pulse duration of sensor signal.

Photonic services enables real-time applications over long distances

The paper introduces photonic service as a new type of multi-domain, end-to-end network service, that besides traditional data transmission enables also non-data or real-time communication, e.g. the remote control and sharing of different, typically unique, devices. We proved the concept of photonic services on a specialized metrology application - comparison of time scales, where time offset between atomic clock is measured over distance of 560km.

Optical stabilization for time transfer infrastructure

In this paper, we propose and present verification of all-optical methods for stabilization of the end-to-end delay of an optical fiber link. These methods are verified for deployment within infrastructure for accurate time and stable frequency distribution, based on sharing of fibers with research and educational network carrying live data traffic. Methods range from path length control, through temperature conditioning method to transmit wavelength control. Attention is given to achieve continuous control for relatively broad range of delays. We summarize design rules for delay stabilization based on the character and the total delay jitter.

Joint accurate time and stable frequency distribution infrastructure sharing fiber footprint with research network

In this paper, we present infrastructure for accurate time and stable frequency distribution. It is based on sharing of fibers of research and educational network carrying data traffic. Accurate time and stable frequency transmission uses mainly created dark channels amplified by special bidirectional amplifiers with the same propagation path for both directions. Paper also targets challenges joined with bidirectional transmission, which represents directional non-reciprocities and interaction with parallel data transmissions.

Coexistence of access and backbone networks with sensor systems

In recent years, new applications as distributed fiber-optic sensing or precise time transfer have been widely studied and developed. Especially, with the growing interest for smart cities sensor networks have been developed intensively. Currently, individual optical fibers are mostly used for individual applications which is very inefficient and uneconomical, especially for longer distances. Moreover, construction of new routes for individual applications is often impossible. It is therefore necessary to use either dark fibers or sharing of a single fiber for multiple applications. Whereas the most of current and newly built access networks are based on optical fiber it is possible to find optical fiber almost everywhere - in city centers, along roads, etc. And since a usable bandwidth of a standard single mode optical fiber is sufficiently large it is appropriate to consider the possibility of coexistence. We performed simulations and experimental measurements to analyze requirements of individual applications and to confirm suitability of coexistence of sensor systems and 1.25 Gbps data transmission in a single optical fiber.

Photonic services for real-time applications

The paper introduces photonic service as a new type of multi-domain, end-to-end network service, that besides traditional data transmission enables also non-data or real-time communication, e.g. the remote control and sharing of different, typically unique, devices. We proved the concept of photonic services on a specialized metrology application - comparison of time scales, where time offset between atomic clock is measured over distance of 550 km.