Communications Network Research Institute

Research Overview

The main theme of the research work carried out the CNRI is the delivery of QoS for real-time services such as VoIP telephony and video streaming over wireless networks based around the IEEE 802.11 family of WLAN standards. These networks are more popularly known as Wi-Fi networks. To this end the CNRI has adopted a cross-layer philosophy where we seek to use information obtained at one particular layer in the communications protocol stack to support and enhance the operation at another layer. Currently, the CNRI is conducting research projects in the area of WLAN mesh networks (WMNs)

The CNRI has developed a number of measurement techniques that pertain to the Medium Access Control (MAC) and Application layers.

At the MAC layer, the CNRI has developed a tool for measuring network bandwidth and these measurements can be used to support codec selection at the Application layer, routing at the Network layer, and link adaptation at the Physical layer.

Similarly, a number of objective techniques for assessing the quality of conversational speech and streamed video have been developed. These Application layer measurements can be used to support the lower layers in the stack. For example, to support QoS routing at the Network layer and to allow for adaptive adjustment of the QoS mechanism parameters at the MAC layer.

MAC Layer

The research activities of the CNRI are based in the following areas: