A novel QoS control scheme using random access period control for wide area ubiquitous wireless networks

In wide area ubiquitous wireless networks, most wireless terminals (WTs) will transmit small amounts of data at comparatively long intervals. Therefore, each AP must be capable of accommodating a great many WTs. Moreover, these networks must accommodate a variety of services; Quality of service (QoS) guarantees are essential. In this paper, we propose a novel QoS control scheme based on random access for wide area ubiquitous wireless networks. To provide QoS guarantees (i.e., required mean delay time), the proposed scheme segregates the random access (RA) periods for the different QoS classes and RA period length is dynamically controlled according to the measured mean delay time; the AP observes the mean delay time and decides the appropriate RA period length from its control history. This scheme guarantees the throughput and delay performance of each QoS class. This paper also clarifies the problems of the conventional scheme and reveals the transmission performance of the conventional and proposed scheme by computer simulation.