Channel preemptive EDCA for emergency medium access in distributed wireless networks

The foray of wireless networks into time-sensitive applications demands support for emergency services, with guaranteed QoS bounds. The IEEE 802.11e technology could be an attractive option for emergency networking, if the protocol design is enhanced to achieve deterministic QoS for emergency traffic during distributed network operation. We propose channel preemptive EDCA scheme, an in-channel service preemption methodology for the 802.11e EDCA framework where emergency traffic incorporates the privileges to preempt the services of lower priority traffic for better QoS guarantees. The CP-EDCA results for emergency frames depict up to 50% decrease in medium access delays and insensitivity to routine traffic competition.