@misc {43389,
	title = {Detecting activity using fibreoptic cable},
	howpublished = {Windforce Baltic Sea 2023 Conference},
	year = {2023},
	url = {https://windforce.info/windforce2023/en/},
	author = {Bj{\o}rnstad, Steinar}
}
@inproceedings { OFS2023,
	title = {Detecting Physical Impacts by Monitoring State of Polarisation in a Live Fibre-To-The-Home Data-Communication Air-Cable},
	journal = {Proceedings of the 28th International Conference on Optical Fiber Sensors~(OFS)},
	year = {2023},
	month = {11/2023},
	publisher = {OPTICA},
	address = {Hamamatsu, Shizuoka/Japan},
	abstract = {Heavy wind may tear cables down, damaging infrastructure, triggering outage in data-communication networks. We demonstrate local observations of wind in the access-network, monitoring State of Polarisation in a live Fiber-To-The-Home air-cable.},
	keywords = {Fibre-To-The-Home, Monitoring, State of Polarisation},
	author = {Bj{\o}rnstad, Steinar and Ali, Jameel and Dreibholz, Thomas}
}
@misc {43388,
	title = {Increasing Availability of Subsea Telecom Infrastructure Through Monitoring Vibrations in Optical Fibre Subsea Cables},
	year = {2023},
	publisher = { Submarine Telecoms Forum},
	abstract = {Society{\textquoteright}s reliance on telecommunication infrastructure continues to grow as both energy and telecommunications solutions share mutual dependencies. This dependency calls for increased monitoring of fibre networks and fibre optic subsea cables, which serve as the backbone of connectivity for all digital communications.Distributed Acoustic Sensing (DAS) and State of Polari- sation (SoP) monitoring provide real-time measurements of vibrations and potential mechanical interference which could impact the cable. Implementation of these sensing technologies mitigate risk to the infrastructure, preventing equipment failure and downtime. In particular, any unexpected movements caused by subsea activities such as passing trawlers, hooking of equipment on the seabed, and any geophysical phenomena can be traced so that appropriate action could be taken.This article will explain the capability and benefits of the monitoring system and how Tampnet utilises this system for monitoring its vast subsea and terrestrial cable systems.},
	url = {https://subtelforum.com/subtel-forum-magazine-131-regional-systems/},
	author = {Bj{\o}rnstad, Steinar and Tysdal, Anders and Lammenes, Cato}
}
@inproceedings { ICTON2023,
	title = {A Scalable Data Collection System for Continuous State of Polarisation Monitoring},
	journal = {Proceedings of the 23rd International Conference on Transparent Optical Networks (ICTON)},
	year = {2023},
	month = {07/2023},
	address = {Bucharest/Romania},
	abstract = {Our dependency on the telecommunication infrastructure is continuously increasing, as different infrastructures {\textendash} such as energy and telecommunication {\textendash} now have mutual dependencies. This calls for increased monitoring of the fibre network, which is a highly critical part of the infrastructure. State of Polarisation (SoP) of light propagating through fibre transmission systems is impacted by any vibrations and mechanical impacts on the fibre. By continuously monitoring the SoP, any unexpected movements of a fibre along a fibre-path may be traced. Movements may be caused by e.g. work in node-rooms impacting patch-cords, trawlers or other types of sub-sea equipment touching or hooking into sub-sea fibre cables, digging close to a fibre-cable, or geophysical phenomena like earthquakes. In this paper, we describe a low-cost, scalable system for SoP monitoring and give examples of patterns monitored in different types of fibre infrastructures. The monitoring system consists of single-unit rack-mount instruments connected to taps from live optical transmission signals. Each instrument has local storage for 1-2 years of data, and is periodically automatically uploading data to a server for backup and data-access purposes. Examples of observed patterns are impact from a thunderstorm on a Fibre-To-The-Home (FTTH) cable, 50 Hz on a fibre-cable spun around a high-voltage power air-cable, as well as animal impact on a patch-cord.},
	keywords = {Critical Infrastructure, Monitoring, State of Polarisation},
	author = {Bj{\o}rnstad, Steinar and Ali, Jameel and Dreibholz, Thomas and S{\ae}thre, Erik}
}
@inproceedings { ConTEL2023,
	title = {A Scalable Infrastructure for Continuous State of Polarisation Monitoring for Revealing Security and Vulnerability Impacts in Optical Networks},
	journal = {Proceedings of the 17th International Conference on Telecommunications (ConTEL)},
	year = {2023},
	month = {07/2023},
	publisher = { IEEE},
	address = {Graz, Steiermark/Austria},
	abstract = {Optical networks are spanning the world. They are the main medium for carrying all types of data-traffic. From a vulnerability and security perspective, it is therefore the most important part of the network to protect against any physical impacts that may cause disruptions or security incidents. In this paper, we demonstrate and describe a scalable, low-cost monitoring system based on detecting the state of polarisation in the fibre cables. We give examples on how any direct movement of fibre-cables or fibre-cords as well as indirect vibrations on the cable can be detected, and how basic characteristics in the patterns can be used for recognition of these events.},
	keywords = {Hardware, Infrastructure, Monitoring, Software, State of Polarisation},
	author = {Dreibholz, Thomas and Bj{\o}rnstad, Steinar and Ali, Jameel}
}
@inproceedings {42734,
	title = {Network Path Integrity Verification using Deterministic Delay Measurements},
	journal = {TMA Conference 2022},
	year = {2022},
	publisher = {IEEE/IFIP},
	abstract = {With the intuition that every device on the data path contributes to the end-to-end delay, we propose a simple and deterministic measurement-based approach for detecting the insertion of a layer-2 switch on the data path of a network operator.\&nbsp;For this purpose, we use commodity hardware and the standard ping tool for collecting ICMP RTTs.\&nbsp;To minimise inaccuracies in the measurements, we increase timing determinism on both ICMP source and target by using a real-time kernel on both, a dedicated source (a Linux server) and target (an RPI4 with custom image). Additionally, we manipulate real-time attributes for prioritising the ping process. By using this approach on different loaded networks: lab, campus network,\&nbsp; research and education network and an ISP, we are able to reliably detect that a switch was added at the end of the path or within it.Our method yields an excellent performance on\&nbsp; networks with considerable cross traffic as well as lightly loaded networks.\&nbsp;},
	keywords = {alien switch, deterministic RTT, network},
	isbn = {978-3-903176-47-8},
	author = {Arouna, Alfred and Bj{\o}rnstad, Steinar and S. J. {Ryan} and Dreibholz, Thomas and Sobia, Rind and Elmokashfi, Ahmed}
}
@misc {43088,
	title = {Using the Fiber Cables as Sensors, Detecting Security Threats and Earthquakes},
	howpublished = {Netnod Technical Meeting, Sweden},
	year = {2022},
	url = {https://www.netnod.se/netnod-tech-meeting-2022},
	author = {Bj{\o}rnstad, Steinar}
}
@misc {28053,
	title = {Anomaly Detection in Optical Links Using State of Polarization Monitoring},
	year = {2021},
	address = {2021 Joint European Conference on Networks and Communications \& 6G Summit, Porto, Portugal},
	keywords = {Anomaly detection, Machine learning, Optical Fibre, State of Polarization},
	url = {https://www.eucnc.eu/poster-a/},
	author = {Bj{\o}rnstad, Steinar and Gulistan, Aamir}
}
@inproceedings {ANRW2020,
	title = {On the Accuracy of Country-Level IP Geolocation},
	journal = {Applied Networking Research Workshop (ANRW)},
	year = {2020},
	month = {07/2020},
	publisher = {ACM},
	address = {Madrid/Spain},
	abstract = {The proliferation of online services comprised of globally spread microservices has security and performance implications. Understanding the underlying physical paths connecting end points has become important. This paper investigates the accuracy of commonly used IP geolocation approaches in geolocating end-to-end IP paths. To this end, we perform a controlled measurement study to collect IP level paths. We find that existing databases tend to geolocate IPs that belong to networks with global presence and those move between networks erroneously. A small percentage of IP geolocation disagreement between databases results in a significant disagreement when geolocating end-to-end paths. Geolocating one week of RIPE traceroute data validates our observations.},
	keywords = {Geolocation Approaches, Geolocation Databases, IP Geolocation},
	isbn = {978-1-4503-8039-3},
	doi = {10.1145/3404868.3406664},
	author = {Livadariu, Ioana and Dreibholz, Thomas and Anas Saeed {Al-Selwi} and Bryhni, Haakon and Lysne, Olav and Bj{\o}rnstad, Steinar and Elmokashfi, Ahmed}
}
@inproceedings {27398,
	title = {Optical Fibre as a Sensor for Network Anomaly Detection},
	journal = {ACM SIGCOMM 2020 Workshop on Optical Systems Design},
	year = {2020},
	abstract = {Optical fibres are the backbone of modern Information Technology infrastructure connecting billions of users through high-speed networks. With a drastic increase in the number of internet users, vulnerability and security issues in the optical fibre network become increasingly important. In this paper, we propose a detection method for early warning of anomalies in optical networks. The method is based on monitoring and analyzing changes in the state of polarization of the optical signal targeting differentiating between different physical impacts and movements of the fibre caused by e.g. eavesdropping, cut by digging and thunderstorms.},
	author = {Gulistan, Aamir and Bj{\o}rnstad, Steinar}
}
@misc {27205,
	title = {Deploying fibre cables for international network connectivity by involving offshore installations},
	howpublished = {NGON \& DCI 2019 - Nice, France},
	year = {2019},
	type = {Invited on commercial conference},
	author = {Bj{\o}rnstad, Steinar}
}
@inproceedings {26425,
	title = {High-speed transport and aggregation for ethernet fronthaul with low and bounded delay},
	journal = {Optical Fiber Communication Conference (OFC) 2019},
	year = {2019},
	publisher = {OSA Publishing},
	doi = {https://doi.org/10.1364/OFC.2019.W4H.2},
	author = {Veisllari, Raimena and Bj{\o}rnstad, Steinar and Fontaine, Micka{\"e}l and Raffaelli, Carla}
}
@misc {27203,
	title = {Hvordan redundans og optisk beskyttelsesomkopling {\o}ker oppetiden til et optisk nett},
	howpublished = {Fiber 2019, Trondheim, Norway},
	year = {2019},
	type = {Invited talk},
	author = {Bj{\o}rnstad, Steinar}
}
@misc {27202,
	title = {Low latency communication from a telecom operator perspective: Examples and techniques},
	howpublished = {ECOC 2019, Dublin, Ireland},
	year = {2019},
	type = {Invited talk in workshop},
	author = {Bj{\o}rnstad, Steinar}
}
@article {26419,
	title = {Minimizing Delay and Packet Delay Variation in Switched 5G Transport Networks},
	journal = {Journal of Optical Communications and Networking},
	volume = {11},
	year = {2019},
	pages = {B49-B59},
	publisher = {IEEE/OSA},
	address = {Piscataway, NJ, USA},
	author = {Bj{\o}rnstad, Steinar and Veisllari, R. and Chen, D. and Tonini, F. and Raffaelli, C.}
}
@inproceedings {27201,
	title = {A Traffic Pattern Adaptive Mechanism to Bound Packet Delay and Delay Variation in 5G Fronthaul},
	journal = {2019 European Conference on Networks and Communications (EuCNC)},
	year = {2019},
	pages = {416-420},
	publisher = {IEEE},
	abstract = {A novel packet-based adaptive mechanism forbounding delay and delay variation in 5G Ethernet fronthaul isproposed. The mechanism enables aggregation of asynchronoustraffic from fronthaul links using a traffic pattern adaptationalgorithm. Traffic of a first stream is added in time-gaps of asecond stream. For bounding and balancing the packet delay anddelay variation between the streams, the size of the requiredtime-gap before insertion is made adaptive. Simulation resultsdemonstrate that through suitable tuning of the algorithm parameters,packet delay and delay variation below 10 microsecondscan be achieved.},
	author = {Tonini, Federico and Raffaelli, Carla and Bj{\o}rnstad, Steinar and Chen, David and Veisllari, Raimena}
}
@misc {27204,
	title = {Ultra high availability in subsea cable networks},
	howpublished = {Inside Telecom 2019},
	year = {2019},
	type = {invited talk},
	author = {Bj{\o}rnstad, Steinar}
}
@inproceedings {26417,
	title = {Can OTN be replaced by Ethernet?},
	journal = {2018 International Conference on Optical Network Design and Modeling (ONDM)},
	year = {2018},
	pages = {220-225},
	publisher = {IEEE},
	doi = {10.23919/ONDM.2018.8396134},
	author = {Bj{\o}rnstad, Steinar}
}
@article {26424,
	title = {C-RAN Traffic Aggregation on Latency-Controlled Ethernet Links},
	journal = {Applied Sciences},
	volume = {8},
	year = {2018},
	pages = {2279},
	publisher = {MDPI},
	doi = {10.3390/app8112279},
	author = {Tonini, F.},
	editor = {B. M. {Khorsandi} and Bj{\o}rnstad, Steinar and Veisllari, R. and Raffaelli, C.}
}
@inproceedings {26420,
	title = {Experimental Demonstration of 100 Gb/s Optical Network Transport and Aggregation for Ethernet Fronthaul with Low and Bounded Delay},
	journal = {Optical Fiber Communication (OFC) 2018},
	year = {2018},
	author = {Veisllari, R.},
	editor = {Bj{\o}rnstad, Steinar and Braute, J.}
}
@inproceedings {26422,
	title = {Field-Trial Evaluation of Low-Latency and Timing-Accurate 100G Ethernet Aggregator for Converged Mobile X-haul},
	journal = {ECOC 2018},
	year = {2018},
	author = {Zou, Jim},
	editor = {Elbers, J{\"o}rg-Peter and Veisllari, Raimena and Jan Petter {Braute} and Fontaine, Micka{\"e}l and Bj{\o}rnstad, Steinar and Rito{\v s}a, Patrik}
}
@inproceedings {26421,
	title = {Handling delay in 5G Ethernet Mobile Fronthaul Networks},
	journal = {2018 European Conference on Networks and Communications (EuCNC)},
	year = {2018},
	pages = {1-9},
	publisher = {IEEE},
	doi = {10.1109/EuCNC.2018.8442755},
	author = {Bj{\o}rnstad, Steinar},
	editor = {Chen, D. and Veisllari, R.}
}
