Tomoaki Kumagai

Enhancement of DCF by multiple data frame transmission scheme based on the number of elapsed contention windows

This paper proposes a new data frame transmission scheme for IEEE 802.11 wireless LAN. IEEE 802.11 wireless LAN employ the binary exponential backoff algorithm to lower the possibility of collisions without reducing efficiency. Unfortunately, it has been shown that the algorithm is, in the short term, highly unfair. To improve the data transmission efficiency, several schemes allow stations to transmit successive frames. Employing these schemes worsens the short-term unfairness. The proposed scheme ties successive transmission to the number of elapsed contention windows to improve the throughput performance without increasing the unfairness. Simulation results show that the proposed scheme achieves high throughput performance while maintaining fairness.

Performance evaluation of the frame bursting method for high speed wireless LAN systems with multirate mechanism

This paper evaluates a novel media access control (MAC) method with multiple frame transmission that increases the throughput performance of high speed wireless local area network (LAN) systems. The current MAC protocol has two problems when used in high speed wireless LAN systems: poor efficiency and the failure to match for a multirate mechanism. The frame bursting method solves these problems by allowing multiple frames to be transmitted within one media access period. The performance evaluations of the frame bursting method are performed by computer simulation. The results demonstrate that the frame bursting method can achieve higher system throughput, 10 Mbit/s, than the system throughput performance of conventional systems. Moreover, the results shows that the frame bursting method works well in the wireless LAN systems that employ the multirate mechanism and can achieve higher throughput performance.