In this paper, we developed an analytical frame work for 802.11 One-ACK protocol under saturated condition with imperfect wireless channel. We developed a probabilistic model to handle the retransmissions of fragmentations which are corrupted due to bad channel condition. A modified Markov chain model is introduced to better model the backoff counter operation. The analytical results are verified against NS-2 simulation with great precision.

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Multi-channel MAC protocols for wireless ad hoc networks have been proposed for improving the effect of traditional hidden terminal problem. However, they may cause another problem called as "multi-channel hidden terminal problem". In this paper, we propose a new multichannel MAC protocol using busy tones in wireless ad hoc networks. In our method, each terminal employs single control channel and some data channels. Moreover, busy tones are used for informing adjacent terminals of utilizing the corresponding channel. Terminals can recognize the channel availability by carrier-sensing busy tones at any time. Therefore, our method can solve multi-channel hidden terminal problem. We evaluate the performance of our method by computer simulation.

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In anycast routing the packet is routed to anyone of the anycast group members. Anycast allows supporting many services and can significantly improve network performance of wireless networks. In this paper, we provide an analysis of anycast routing in mobile ad hoc networks. We also show the correlation between mobility and the probability of connected route in anycast scenario and impact of the node degree density. To evaluate improvement of the network performance we design anycast proactive protocol with two modes. The first routing mode considers only the shortest path routing and another considers also the node degree density through the count of routes to the anycast group member. We also compare the performance with a potential field-based proactive anycast protocol.

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A handoff algorithm with the criterion of linear combination of RSSI (Received Signal Strength Indicator) and distance is proposed. The system model under study is a multi-hop network with two fixed access points, some moving terminal repeaters, and a mobile terminal. The mobile terminal moves from one access point to the other, and makes handoff thru the terminal repeaters to maintain access to service. Simulation is made and the results are compared against the RSSI-only algorithm and the distance-assisted algorithm [2]. It is found that the proposed algorithm achieves lower handoff percentage and outage occurrence.

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This paper presents an integrated method of market data and simulation for demand forecasting of Eco-car. For acquiring market data by using conjoint analysis, we conduct a stated preference experiment, thereby predicting a potential share of Eco-car which is used in the Bass model in simulation. The Bass model simulates a diffusion process of new product of durables. In the simulation, a time series model of total demand for the product on the Bass model is introduced. In the experiments, we conduct a internet survey on 49 cities in Japan and obtain the part-worth utilities for the level of attributes of Eco-car. Then using by the Bass model under the scenario of regular gasoline prices, the time series prediction of Eco-car and Kei car is done in 2010 up to 2040, and is also used to assess the influence on CO2 emissions. The proposed method allows the researcher to examine the scenario analysis on the diffusion of new products.

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