A common strategy for responding to indoor emergency scenarios is to rapidly deploy a group of first responders inside the incident area and an incident command center outside of the incident area. First responders are equipped with radios that allow them to communicate directly with the incident command. However, if the communication environment within the incident area is inadequate, communication between the first responders and the incident command may be compromised affecting the ability of the incident command to control the operation. In , we investigated the use of multi-hop relays (a.k.a breadcrumbs) to extend the range of public safety communications in indoor environments where the radio propagation conditions are harsh or wireless communications are limited by distance. In this work, we consider the impact of interference on the reliability of the breadcrumb system. We develop a simulation model for the breadcrumb system in ns-2 that considers the incident area floor plan, the characteristics of radio propagation within the incident area, first responders mobility, and the distributed functionalities of the breadcrumb system. We then evaluate the performance of the breadcrumb system in the presence of interference showing that it is diminished. Consequently, we propose the use of cognitive radios to enable breadcrumbs to detect interference, to identify vacant channels, and to dynamically and autonomously adapt their channel selection to enhance the system performance. We develop the functionalities of cognitive radio in our ns-2 simulator, re-evaluate the system performance in the presence of interference, and show that employing cognitive radios improves the network performance significantly.
Conference Dates: April 18, 2008
Conference Location: Phoenix, AZ
Conference Title: IEEE Workshop on Mission Critical Networks (Infocom)
Pub Type: Conferences
Cognitive radio, Mission Critical Networks