In this letter, we present the throughput analysis of the wireless ad hoc networks based on the IEEE 802.11 MAC (Medium Access Control). Especially, our analysis includes the case with the hidden node problem so that it can be applied to the multi-hop networks. In addition, we suggest a new channel access control algorithm to maximize the network throughput and show the usefulness of the proposed algorithm through simulations.

IEEE 802.11 MAC is the most commonly used MAC layer protocol in multi-hop ad hoc networks. When the network load becomes heavy, the throughput performance of IEEE 802.11 MAC is decreased because of the high collision rates and the low spatial reuse of the channel. In this letter, we analyze the throughput of multi-hop ad hoc networks and propose a supervisory control framework to maximize the throughput.

In this letter, we suggest APMAC (Adaptive Power Control MAC) for wireless ad hoc networks. APMAC is based on the single channel environment and improves the throughput and the energy efficiency simultaneously. Furthermore, the APMAC prevents the unfair channel starvation among the transmission pairs. We verify the performance of the APMAC through simulations.

The current congestion control mechanism for TCP with ECN suffers from the oscillation of the window size and the unfair sharing of network resources. These problems are caused by the insufficient information about the congestion level of a network and the different round trip time (RTT) among the connections respectively. In this paper, we propose a new window control algorithm for TCP with ECN to avoid the oscillation of the window size and to achieve the fairness among the connections.

IEEE 802.11 Media Access Control (MAC) is the most widely used protocol in Wireless Ad-hoc Networks (WANETs). However, it cannot guarantee fair channel allocation among the flows contending for the channel. In this paper, we propose a new media access control algorithm to achieve per-flow fairness while maximizing WANETs throughput.

In this letter, we suggest a rate-based supervisory congestion control scheme for the ad hoc networks that use TCP as the transport protocol. This scheme makes it possible for the TCP sender to distinguish the causes of packet loss. In addition, this scheme guarantees the fair sharing of the available bandwidth among the connections. We show the reliability of our scheme by using the supervisory control framework and simulations confirm the effectiveness of our scheme.

A numerical model of multi-layered organic light emitting diode (OLED) is presented in this paper. The current density-voltage (J-V) model for OLED was performed by using the injection-limited current and bulk-limited current. The mobility equation was based on the field dependent model, so called “Poole-Frenkel mobility model.” The accuracy of this simulation was represented by comparing to the experimental results with a variable of EML thickness of multi-layered OLED device. There are two hetero-junction models which should be dealt with in the simulation. The Langevin recombination rate of electron and hole is also calculated through the device simulation.