Masatoshi Kakiuchi

Reproducing and Extending Real Testbed Evaluation of GeoNetworking Implementation in Simulated Networks

Vehicular Ad-hoc Network (VANET) is a type of Mobile Ad-hoc Network (MANET) which is specialized for vehicle communication. GeoNetworking is a new standardized network layer protocol for VANET which employs geolocation based routing. However, conducting large scale experiments in GeoNetworking softwares is extremely difficult, since it requires many extra factors such as vehicles, stuff, place, terrain, etc. In this paper, we propose a method to reproduce realistic results in simulation with the same software implementation. The key idea of the method is to calibrate simulator with the results of real world testbed experiments. After the simulator was calibrated, some extended experiments were carried out. Through these experiments, the fundamental functions of the GeoNetworking implementation (BTP, Greedy Forwarding, etc.) are verified, while an issue in algorithm was discovered and analyzed.

Vehicle clustering algorithm for sharing information on traffic congestion

We present a method for clustering vehicles that are in the same congested traffic flow. Our goal is to provide a mechanism for sharing information between vehicles in the same situation to ease traffic congestion in urban areas. Because the most accurate source of information about the congested traffic flow is the vehicle at the head of the traffic flow, it first needs to be identified. To do so, we adapt a clustering algorithm by trajectory abstraction. By grouping the vehicles that have the same or similar trajectory into the same cluster, the vehicle at the tail of the traffic flow can discover the vehicle at the head of the traffic flow. Moreover, we adapt an abstracted trajectory representation to compensate for the error in GPS information. Simulation results show that the proposed algorithm provides a higher rate of correctness than existing commonly used clustering algorithms.

Location tracking prevention with dummy messages for vehicular communications

In emerging vehicular communication systems, each vehicle periodically broadcasts safety messages, which contains various vehicle parameters such as location and velocity. While safety messages are designed for advanced road safety and traffic efficiency, a significant concern is that eavesdroppers can track the vehicles trajectory. In particular, this tracking is easily performed in low vehicle density environments. To address this location privacy issue, we propose a location privacy protection method in such environments using dummy node messages. In our approach, from an eavesdroppers view, the vehicle density is increased by the generation of dummy node messages. Simulation results show that our proposed method reduces tracking probability in high/low vehicle density environments.

KUPF: 2-phase selection model of classification records

With the advance of computing and internetworking technologies, various services, which need classification of data, are provided. Firewall and QoS control are typical services which classify the data flow. These services are based on two or more rules, and select a rule to classify the data. However, some of their rules may conflict with one another and it is necessary to resolve conflicts in these classification mechanisms. We discuss the classification of data with generalization of the parameter filter. Then we arrange the parameter filter and propose a 2-phase selection model of classification records. In this model, we consider the procedure of the parameter filter as the phase depending only on the schema of the filter rule and the phase depending on the service. We also implement the KUPF framework based on this model and a sample service which provides QoS control over a IPv4/IPv6 network. With this sample implementation, we validate the availability and evaluate the performance of KUPF.

A vehicle clustering algorithm for information propagation by inter-vehicle communications

There are some cases regarding information propagation over a wide area, such as Vehicle-to-Vehicle (V2V) communications, in which an end-to-end path does not exist, due to the non-uniform density of vehicles. In order to solve this problem, Delay Tolerant Network (DTN) architectures have been studied to facilitate message delivery in V2V communications. However, existing message delivery methods for the purpose of information sharing do not consider the efficiency of message passing communications. As a result, information can be lost, due to a decrease in the efficiency of information propagation. In order to increase the efficiency of information propagation, we propose a vehicle clustering algorithm, based on the similarity of geographic locations and trajectories. This contributes to efficient message passing communication. In order to evaluate our proposal, we carry out a simulation. The simulation results confirm that our proposed method provides higher message reachability, and utilizes bandwidth more efficiency than existing methods.

Uncompressed 4K2K and HD live transmission on global internet

There are some researches in transmission of high definition image using Internet Protocol (IP) before. Materials for TV stations require lossless transmission by uncompressed real-time transmission. Also high performance camera and display require transmission methods for 4K2K (3,840 x 2,160 pixels) image over HD (High Definition; 1,920 x 1,080 pixels). Especially, projection to huge screen such planetarium requires at least 4K2K resolution. However, uncompressed transmission of both HD and 4K2K require such high bandwidth network as 1.6 Gbit/s and 6.4 Gbit/s, then we prepared dedicated networks such SONET or wide-area VLAN service. Therefore we spent a lot of procedures and costs.

Total solar eclipse: fish-eye 4K image transmission experimentation on the internet

The total solar eclipse of July 22, 2009 was the longest that of the 21st century, many astronomy shows were held in Asia. To transmit this valuable moment to a distant area with enough liveliness, we considered a mechanism how to transmit. Only that transmits the image of the corona or the diamond ring which the moon lines up with the sun like existing methods, it is difficult to say that we can transmit a total solar eclipse perfectly. In this research, we succeeded in transmitting not only the image of the sun but also the image of the whole sky all with an atmosphere.