Mobile Computing and Communications Lab
The Mobile Computing and Communications Laboratory, led by Prof. Wha Sook Jeon, was founded in the Department of Computer Engineering at Seoul National University in March 1999. Group members are involved in research projects focused on the emerging needs of the wireless communications industry. Over the years of research on mobile computing and communications, we have made a number of technical contributions to cognitive radio, network architectures and protocols, radio resource management and network performance evaluation.
Cognitive radio technology is the novel approach to maximize the utilization of scarce radio spectrum. It is achieved by using spectrum holes which indicate parts of wireless spectrum unused at a particular time and a specific geographical location. In order to find spectrum holes, the cognitive radio system should scan wide spectrum band. The cognitive radio system can use a found spectrum hole until the primary user starts to transmit. After detecting the presence of primary user, the cognitive radio system should change its operating frequency band to another empty one.
Radio Resource Management
In wireless communication systems, efficient resource usage is very important since the wireless resources are scarce. On the other hand, various multimedia services have the different quality-of-service (QoS) requirements with respect to each other. Radio resource management aims at improving the overall system utilization while satisfying various QoS requirements of services. It involves algorithms and strategies for controlling the input traffic load of system, the order of packet transmission, transmit power, channel allocation, and the level of modulation and coding, etc.