The current version of IEEE 802.11, based on EDCA, is unable to support fine-grained assignments of priorities to messages. Instead, such an ability could be advantageous in distributed real-time control systems communicating over the air, as it would enable the exploitation of feasibility analysis to assess whether or not timing constraints are met. In this paper, a proposal is made for implementing a simple fixed-priority access scheme on conventional Wi-Fi devices. Basically, this is obtained by disabling the random backoff mechanism and suitably managing interframe gaps only. In particular, each real-time message is assigned a unique gap duration, so as to help in preventing collisions. An experimental campaign has been carried out on real devices aimed at assessing the performance this approach can achieve.
A Fixed-Priority Access Scheme for Industrial Wi-Fi Networks
G Cena;S Scanzio;L Seno;A Valenzano
2016
Abstract
The current version of IEEE 802.11, based on EDCA, is unable to support fine-grained assignments of priorities to messages. Instead, such an ability could be advantageous in distributed real-time control systems communicating over the air, as it would enable the exploitation of feasibility analysis to assess whether or not timing constraints are met. In this paper, a proposal is made for implementing a simple fixed-priority access scheme on conventional Wi-Fi devices. Basically, this is obtained by disabling the random backoff mechanism and suitably managing interframe gaps only. In particular, each real-time message is assigned a unique gap duration, so as to help in preventing collisions. An experimental campaign has been carried out on real devices aimed at assessing the performance this approach can achieve.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.