Abstract-Although a number of investigations have been conducted using IEEE 802.11e enabled networks to stream class differentiated video, very few reports are available based on a real testbed. In our work, we set up a wireless testbed for H.264 video streaming through assigning the partitioned video packets onto the DCF MAC layer and different access classes of the EDCA MAC layer. We investigate three assignment schemes: 1) DCF is used and all the traffic is treated equally; 2) video traffic is assigned to each of the access classes in turn; and 3) the packets are assigned according to their importance and the class priority. In addition to the video stream we introduce TCP traffic from three clients in the best effort class. We show that video quality can be improved through properly assigning packets to wireless access classes compared to the standard best effort scheme. Importantly, we show, based on our testbed results, that the single class assignment can achieve better performance than the multi-class assignment suggested by other researchers. Finally we show that virtual contention between traffic classes at the access point is an important issue to address.

There has been considerable research into the performance of the enhanced IEEE 802.11e standard in recent years. Majority of the performance analysis has been based on simulations and analytical models, with little testing done in a real-world environment. We investigate the behaviors of the Enhanced Distributed Channel Access (EDCA) and legacy Distributed Coordination Function (DCF) based on a testbed operating in a realistic working environment. Both TCP/UDP streams representing traffic types such as FTP and VoIP are tested. Quality of Service (QoS) metrics such as Throughput and Delay are calculated directly from a passive capture of the channel. These metrics can also be converted into physical layer requirements such as Signal to Noise ratio. EDCA and DCF are shown to have similar performances with single streams of traffic, which are contributed directly by the loss effect at the MAC layer.

Abstract-We investigate the performance of IEEE802.11e Enhanced Distributed Channel Access (EDCA) using real world hardware in a realistic indoor working environment. TCP streams of different priorities representing traffic types, such as FTP are tested over a wireless network test-bed. Quality of Service (QoS) metrics such as throughput and delay are calculated directly from a passive capture of the channel. We show that EDCA is capable of providing service differentiation. However the QoS guarantee for high priority stations is achieved at the expense of service provided to stations with lower priority.

This paper introduces a patient information management system that uses location tracking of WiFi tagged patients to provide reliable and up-to-date patient information for surgical processes and other clinical sessions. Such a system could eliminate human error in patient identification (saving lives) and enhance hospital resource utilisation. The paper also describes how the information is secured during the dissemination and manipulation processes in the distributed and wireless environments. The system design has addressed several technical challenges such as service assurance, location awareness and security, which leads to a multi-mode (pull, push and combination) and highly available information system for hospital resource and patient management.