Radio Frequency over Fibre Optics Repeater for Mission-Critical Communications: Design, Execution and Test.

Răzvan-George Bărtuşică,Mădălin Mihai,Simona Halunga,Octavian Fratu

doi:10.3390/s22020612

Abstract

This paper presents a technical solution that addresses mission-critical communications by extending the radio frequency coverage area using a flexible and scalable architecture. One of the main objectives is to improve both the reaction time and the coordination between mission-critical practitioners, also called public protection and disaster relief users, that operate in emergency scenarios. Mission-critical services such as voice and data should benefit from reliable communication systems that offer high availability, prioritization and flexible architecture. In this paper, we considered Terrestrial Trunked Radio (TETRA), the mobile radio standard used for mission-critical communications, as it has been designed in this respect and is widely used by first responder organizations. Even if RF coverage is designed before network deployment and continuously updated during the lifetime of the technology, some white areas may exist and should be covered by supplementary base stations or repeaters. The model presented in this paper is an optical repeater for TETRA standard that can offer up to 52.6 dB downlink, 65.6 dB uplink gain and up to 3.71 km coverage distance in a radiating cable installation scenario. The design in not limited, as it can be extended to several different mobile radio standards using the same principle. Flexibility and scalability attributes are taken into consideration, as they can build a cost-effective deployment considering both capital and operational expenditures.

Highlights

IntroductionCritical communications can be defined as reliable communications between first responders (e.g., police, fire brigade, medical staff, etc.) during mission scenarios
Critical communications can be defined as reliable communications between first responders during mission scenarios
In each deployment scenario there are always two pick-up modes available: by antenna or via direct connection to the base station or another repeater. While the former mode can be performed at any site with the disadvantage of receiving a low RF signal depending on the distance to the base station/repeater, the latter is not signal restrictive, but the pick-up system should be installed in the same site

Summary

Introduction

Critical communications can be defined as reliable communications between first responders (e.g., police, fire brigade, medical staff, etc.) during mission scenarios. Mission-critical communications rely on operational mobility which provides a uniform service access and level of reliability for users, regardless of the area in which they operate. Another important aspect is the need for high availability of the communication system. A high availability (e.g., at least 99.99% uptime considered for one year reference, or approximately 5 min of downtime per month) represents a good indicator for reliable critical communications. The Terrestrial Trunked Radio (TETRA) [1,2,3] is a European professional mobile radio standard, especially designed for military communications, for emergency (police, fire, ambulance) services as well as for transport and public safety networks. The transmission rates are relatively low compared to modern application requirements

Methods

Results

Conclusion