# Temporal Connectivity: Coping with Foreseen and Unforeseen Delays

Eugen Füchsle, Hendrik Molter, Rolf Niedermeier, Malte Renken

  * Department of Industrial Engineering and Management



Research output: Chapter in Book/Report/Conference proceeding › Conference contribution › peer-review

## Abstract

Consider planning a trip in a train network. In contrast to, say, a road network, the edges are temporal, i.e., they are only available at certain times. Another important difficulty is that trains, unfortunately, sometimes get delayed. This is especially bad if it causes one to miss subsequent trains. The best way to prepare against this is to have a connection that is robust to some number of (small) delays. An important factor in determining the robustness of a connection is how far in advance delays are announced. We give polynomial-time algorithms for the two extreme cases: delays known before departure and delays occurring without prior warning (the latter leading to a two-player game scenario). Interestingly, in the latter case, we show that the problem becomes PSPACE-complete if the itinerary is demanded to be a path.

Original language | English  
---|---  
Title of host publication | 1st Symposium on Algorithmic Foundations of Dynamic Networks, SAND 2022  
Editors| James Aspnes, Othon Michail  
Publisher| Schloss Dagstuhl- Leibniz-Zentrum fur Informatik GmbH, Dagstuhl Publishing  
ISBN (Electronic)| 9783959772242  
DOIs| 

  * https://doi.org/10.4230/LIPIcs.SAND.2022.17

  
State| Published - 1 Apr 2022  
Event| 1st Symposium on Algorithmic Foundations of Dynamic Networks, SAND 2022 \- Virtual, Online  
Duration: 28 Mar 2022 → 30 Mar 2022  
  
### Publication series

Name| Leibniz International Proceedings in Informatics, LIPIcs  
---|---  
Volume| 221  
ISSN (Print)| 1868-8969  
  
### Conference

Conference| 1st Symposium on Algorithmic Foundations of Dynamic Networks, SAND 2022  
---|---  
City| Virtual, Online  
Period| 28/03/22 → 30/03/22  
  
## Keywords

  * PSPACE-completeness
  * Paths and walks in temporal graphs
  * dynamic programming
  * flow computations
  * static expansions of temporal graphs
  * two-player games



## ASJC Scopus subject areas

  * Software



## UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

  * 


## Access to Document

  * 10.4230/LIPIcs.SAND.2022.17




## Other files and links

  * Link to publication in Scopus




##  Fingerprint

Dive into the research topics of 'Temporal Connectivity: Coping with Foreseen and Unforeseen Delays'. Together they form a unique fingerprint. 

  * Polynomial-time Algorithm Keyphrases 100%
  * Road Network Keyphrases 100%
  * Case Delay Keyphrases 100%
  * Two-player Games Keyphrases 100%
  * Small Delay Keyphrases 100%
  * PSPACE-complete Keyphrases 100%
  * Game Scenarios Keyphrases 100%
  * Temporal Connectivity Keyphrases 100%



## Cite this

Füchsle, E., Molter, H., Niedermeier, R., & Renken, M. (2022). Temporal Connectivity: Coping with Foreseen and Unforeseen Delays. In J. Aspnes, & O. Michail (Eds.), _1st Symposium on Algorithmic Foundations of Dynamic Networks, SAND 2022_ Article 17 (Leibniz International Proceedings in Informatics, LIPIcs; Vol. 221). Schloss Dagstuhl- Leibniz-Zentrum fur Informatik GmbH, Dagstuhl Publishing. https://doi.org/10.4230/LIPIcs.SAND.2022.17

Füchsle, Eugen ; Molter, Hendrik ; Niedermeier, Rolf et al. / **Temporal Connectivity : Coping with Foreseen and Unforeseen Delays**. 1st Symposium on Algorithmic Foundations of Dynamic Networks, SAND 2022. editor / James Aspnes ; Othon Michail. Schloss Dagstuhl- Leibniz-Zentrum fur Informatik GmbH, Dagstuhl Publishing, 2022. (Leibniz International Proceedings in Informatics, LIPIcs).

@inproceedings{0ac3c58f1b6f438dae63dd813c9d77d3,

title = "Temporal Connectivity: Coping with Foreseen and Unforeseen Delays",

abstract = "Consider planning a trip in a train network. In contrast to, say, a road network, the edges are temporal, i.e., they are only available at certain times. Another important difficulty is that trains, unfortunately, sometimes get delayed. This is especially bad if it causes one to miss subsequent trains. The best way to prepare against this is to have a connection that is robust to some number of (small) delays. An important factor in determining the robustness of a connection is how far in advance delays are announced. We give polynomial-time algorithms for the two extreme cases: delays known before departure and delays occurring without prior warning (the latter leading to a two-player game scenario). Interestingly, in the latter case, we show that the problem becomes PSPACE-complete if the itinerary is demanded to be a path.",

keywords = "PSPACE-completeness, Paths and walks in temporal graphs, dynamic programming, flow computations, static expansions of temporal graphs, two-player games",

author = "Eugen F{\"u}chsle and Hendrik Molter and Rolf Niedermeier and Malte Renken",

note = "Publisher Copyright: {\textcopyright} Eugen F{\"u}chsle, Hendrik Molter, Rolf Niedermeier, and Malte Renken; licensed under Creative Commons License CC-BY 4.0; 1st Symposium on Algorithmic Foundations of Dynamic Networks, SAND 2022 ; Conference date: 28-03-2022 Through 30-03-2022",

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Füchsle, E, Molter, H, Niedermeier, R & Renken, M 2022, Temporal Connectivity: Coping with Foreseen and Unforeseen Delays. in J Aspnes & O Michail (eds), _1st Symposium on Algorithmic Foundations of Dynamic Networks, SAND 2022._ , 17, Leibniz International Proceedings in Informatics, LIPIcs, vol. 221, Schloss Dagstuhl- Leibniz-Zentrum fur Informatik GmbH, Dagstuhl Publishing, 1st Symposium on Algorithmic Foundations of Dynamic Networks, SAND 2022, Virtual, Online, 28/03/22. https://doi.org/10.4230/LIPIcs.SAND.2022.17

**Temporal Connectivity: Coping with Foreseen and Unforeseen Delays.** / Füchsle, Eugen; Molter, Hendrik; Niedermeier, Rolf et al.   
1st Symposium on Algorithmic Foundations of Dynamic Networks, SAND 2022. ed. / James Aspnes; Othon Michail. Schloss Dagstuhl- Leibniz-Zentrum fur Informatik GmbH, Dagstuhl Publishing, 2022. 17 (Leibniz International Proceedings in Informatics, LIPIcs; Vol. 221).

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution › peer-review

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T2 - 1st Symposium on Algorithmic Foundations of Dynamic Networks, SAND 2022

AU - Füchsle, Eugen

AU - Molter, Hendrik

AU - Niedermeier, Rolf

AU - Renken, Malte

N1 - Publisher Copyright: © Eugen Füchsle, Hendrik Molter, Rolf Niedermeier, and Malte Renken; licensed under Creative Commons License CC-BY 4.0

PY - 2022/4/1

Y1 - 2022/4/1

N2 - Consider planning a trip in a train network. In contrast to, say, a road network, the edges are temporal, i.e., they are only available at certain times. Another important difficulty is that trains, unfortunately, sometimes get delayed. This is especially bad if it causes one to miss subsequent trains. The best way to prepare against this is to have a connection that is robust to some number of (small) delays. An important factor in determining the robustness of a connection is how far in advance delays are announced. We give polynomial-time algorithms for the two extreme cases: delays known before departure and delays occurring without prior warning (the latter leading to a two-player game scenario). Interestingly, in the latter case, we show that the problem becomes PSPACE-complete if the itinerary is demanded to be a path.

AB - Consider planning a trip in a train network. In contrast to, say, a road network, the edges are temporal, i.e., they are only available at certain times. Another important difficulty is that trains, unfortunately, sometimes get delayed. This is especially bad if it causes one to miss subsequent trains. The best way to prepare against this is to have a connection that is robust to some number of (small) delays. An important factor in determining the robustness of a connection is how far in advance delays are announced. We give polynomial-time algorithms for the two extreme cases: delays known before departure and delays occurring without prior warning (the latter leading to a two-player game scenario). Interestingly, in the latter case, we show that the problem becomes PSPACE-complete if the itinerary is demanded to be a path.

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Füchsle E, Molter H, Niedermeier R, Renken M. Temporal Connectivity: Coping with Foreseen and Unforeseen Delays. In Aspnes J, Michail O, editors, 1st Symposium on Algorithmic Foundations of Dynamic Networks, SAND 2022. Schloss Dagstuhl- Leibniz-Zentrum fur Informatik GmbH, Dagstuhl Publishing. 2022. 17. (Leibniz International Proceedings in Informatics, LIPIcs). doi: 10.4230/LIPIcs.SAND.2022.17