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Títol: Multiple links to enhance the reliability of IEEE 802.11be transmissions


Estudiants que han llegit aquest projecte:


Director/a: GARCÍA VILLEGAS, EDUARD

Departament: ENTEL

Títol: Multiple links to enhance the reliability of IEEE 802.11be transmissions

Data inici oferta: 02-07-2019     Data finalització oferta: 02-03-2020



Estudis d'assignació del projecte:
    GR ENG SIS TELECOMUN
    GR ENG TELEMÀTICA
Tipus: Individual
 
Lloc de realització: EETAC
 
Paraules clau:
Wi-Fi, TSN, reliability
 
Descripció del contingut i pla d'activitats:
Its prominent position as non-line of sight (NLoS) RAT for data communications in small cells, along with its continuous evolution, make the IEEE 802.11 family of standards a good candidate to play a key role in future 5G deployments. The evolution towards 5G RAN brings new challenges in terms of time synchronisation requirements imposed to radio transmissions. To achieve such accuracy in the transport of timing, the expectation is to continue relying on a mix of centralised or distributed Global Navigation Satellite Service (GNSS) receivers networked towards the synchronisation clients (e.g., base stations) through packet-based timing transport such as IEEE 1588 PTP.

This has been the conventional approach due to inviable costs of deploying GNSS receivers in every base station, especially when considering indoor equipment. However, IEEE 802.11-based technologies pose several challenges for synchronisation, not only as a transport means for synchronisation signalling, but also as the target of the synchronisation itself in order to run time-sensitive mechanisms.

The first objective of this project is to measure the precision of the synchronisation achieved by Wi-Fi nodes with different synchronisation sources, including GPS (or other GNSSs) receivers and the exploration of synchronisation through a secondary radio both in an out-of-band or in-band fashion. Second, with regards to Wi-Fi-based transport nodes used to distribute synchronisation signalling through, e.g., IEEE 1588, it is interesting to explore the limits of the accuracy achieved by a multi-hop wireless mesh network, where CSMA-based wireless transmitters are used as transparent clocks or boundary clocks where each node in the path acts both as a slave in uplink direction and as master in the downlink (i.e., towards the farthest access node).
 
Overview (resum en anglès):
The increasing need for faster, reliable and latency bounded solutions, especially in the industrial, medical and audiovisual fields, alongside the demand for mobility and ease of configuration, make the fusion of IEEE 802.11 (“Wi-Fi”) and Time-Sensitive Networking (TSN) more necessary than ever. The evolution of high-quality video, the implementation of telesurgery in health care and haptic technology in industries brings a wide variety of new challenges in time synchronization, latency, reliability and management of resources. To achieve such specifications, formerly all the transmissions were wired, as the wireless solutions could not compete especially in terms of reliability and bounded delay. Nowadays, considering the current most notorious iteration of the wireless communications standard, IEEE 802.11ac, with a slight look into the newest improvements in TSN for the upcoming version IEEE 802.11be and the up-to-date publications for the TSN related amendments under IEEE 802.1, it is obvious that there is a remarkable interest in enhancing the Wi-Fi technology for these kinds of scenarios. In this work, the concepts of the two technologies mentioned above are studied, specifically at the physical and link layers, to then develop a simulator with which to study the behaviour of a wireless system in response to a set of input parameters and its operation is validated according to different theoretical calculations. In addition, the tool implements a behaviour similar to IEEE 802.1CB (Frame Duplication), in which the packets to be transmitted are sent over all parallel links to increase reliability. Finally, different combinations of parameters are tested to see how they affect the link conditions, the number of links, and the possible retransmissions to the system's behaviour. Moreover, use cases are exposed in which the tool could be useful to find the best configuration parameters to meet the requirements in terms of reliability and latency between packets.


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