Improved channel access control scheme supporting priority service for third generation mobile communication system

Abstract

Since the first generation mobile communication systems have been developed in 1970`s and 1980`s to provide voice based communication service, mobile communication systems have been widespread and have firm ground more and more in telecommunication industry. As the needs for advanced service grow, the second generation mobile communication systems have been introduced in 1980`s and 1990`s, and the third generation mobile communication system called IMT-2000 are being actively researched and developed for standardization. The third generation mobile communication systems will support voice, video, and low to high rate data services. So, these systems must have large capacity, ability to transfer data with various rates, and flexibility to support a wide range of environments. These systems are based on wideband CDMA (WCDMA) technologies and define a set of physical and logical channels, among which some channels are dedicated and some are common. Circuit voice and high rate data services are supported through dedicated traffic channels, however other packet based data services with short duration, such as Short Message Services (SMS), E-mail Indication Services, and signaling messages are provided through common traffic channels. It becomes important how to efficiently use limited wireless resources. Common Packet Channel (CPCH) is a uplink common traffic channel and a collision based random access channel, that is adopted to carry small and medium sized messages in WCDMA system. The basic CPCH mechanism has been proposed and adopted for the packet transmission over CPCH channels. There have been many discussions related to the CPCH mechanism. To improve the efficiency, the CPCH mechanism with channel assignment and the CPCH mechanism with status monitoring have been proposed. These enhanced mechanisms can increase the throughput and reduce the delay, however they require more complex facility and cause more cost. And, the previous CPCH mechanisms cannot provide...