Vjaceslavs Bobrovs

By Jurgis Porins, Vjaceslavs Bobrovs and Girts Ivanovs

Part of the book: Optical Communications Systems

By Vjaceslavs Bobrovs and Girts Ivanovs

Part of the book: Optical Communication

By Oskars Ozolins, Vjaceslavs Bobrovs, Jurgis Porins and Girts Ivanovs

Part of the book: Current Trends in Short- and Long-period Fiber Gratings

By Vjaceslavs Bobrovs, Jurgis Porins, Sandis Spolitis and Girts Ivanovs

Part of the book: Advances in Optical Communication

By Vjaceslavs Bobrovs, Sergejs Olonkins, Sandis Spolitis, Jurgis Porins and Girts Ivanovs

Over the past two decades, a rapid expansion of the amount of information to be transferred has been observed. This tendency is explained by the rapid increase of Internet and other service users, as well as with the increasing availability of these services. This rapid growth in the amount of globally transmitted data is also associated with the expansion of the range of services offered, including such resource-consuming services as high-resolution video transmission, videoconferencing, and cloud computing, as well as with increasing popularity of such services. To satisfy this constantly increasing demand for higher network capacity, fiber optical transmission systems have been studied and applied with a growing intensity. Currently, optical transmission systems with wavelength-division multiplexing (WDM) have attracted much attention, as this technology allows using the available optical fiber resources more effectively than alternative technologies.

Part of the book: Optical Fiber and Wireless Communications

By Guntis Ancans and Vjaceslavs Bobrovs

The increased demand of consumers on services in the mobile broadband environment with high data rate and developed mobile broadband communication systems will require more spectrum to be available in the future. New technologies as well as the existing services require frequencies for their development. In this chapter, we investigate the available and potential future mobile terrestrial radio frequency bands (5G)—worldwide and in Europe. An insight into the mobile spectrum estimate is provided. Characteristics and requirements of IMT-2020, future possible IMT frequency bands, and examples of 5G usage scenarios are also addressed in the chapter. Electromagnetic compatibility evaluation methods are provided mainly focusing on existent mobile technologies below 1 GHz where also 5G technologies will be developed in the future. It is stressed that the radio frequency spectrum is a limited national resource that will become increasingly precious in the future.

Part of the book: Broadband Communications Networks

By Toms Salgals, Inna Kurbatska, Sandis Spolitis, Vjaceslavs Bobrovs and Girts Ivanovs

The exponential growth of Internet data traffic and progress of Information and Communication Technology (ICT) sector pushes hard the telecommunication infrastructure for upgrading the transmission data rate. Wavelength division multiplexed passive optical networks (WDM-PONs) can be the next generation solution for nowadays problems which are related to transmission capacity. Next-generation WDM-PON systems based on mixed wavelength transmitters are expected to become more cost-efficient at high per user data rates, e.g., over 10 Gbit/s per channel. Important advantage of this technology is to set various channel spacing and use different modulation formats to increase spectral efficiency in the same time and provide different transmission speeds for end user, based on pay-as-you-grow approach. Therefore, several modulation formats like non-return to zero (NRZ) also called 2-level pulse-amplitude modulation (PAM-2), four level PAM or PAM-4 and Duobinary (DB) are investigated to understand their limitations, advantages and disadvantages to be further used in next generation PON systems to increase its capacity and spectral efficiency.

Part of the book: Telecommunication Systems

By Janis Braunfelds, Sandis Spolitis, Jurgis Porins and Vjaceslavs Bobrovs

Fiber Bragg grating (FBG) sensors are a progressive passive optical components, and used for temperature, strain, water level, humidity, etc. monitoring. FBG sensors network can be integrated into existing optical fiber network infrastructure and realized structural health monitoring of roads, bridges, buildings, etc. In this chapter, the FBG sensor network integration in a single-channel and multi-channel spectrum sliced wavelength division multiplexed passive optical network (SS-WDM-PON) is presented and assessed. The operation of both the sensors and data transmission system, over a shared optical distribution network (ODN), is a challenging task and should be evaluated to provide stable, high-performance mixed systems in the future. Therefore, we have investigated the influence of FBG temperature sensors on 10 Gbit/s non-return-to-zero on–off keying (NRZ-OOK) modulated data channels optical transmission system. Results show that the crosstalk between both systems is negligible. The successful operation of both systems (with BER < 2 × 10−3 for communication system) can be achieved over ODN distances up to 40 km.

Part of the book: Application of Optical Fiber in Engineering