Jung-Il Namgung

SBMAC: Smart Blocking MAC Mechanism for Variable UW-ASN (Underwater Acoustic Sensor Network) Environment

In this paper, several MAC scheduling methods applicable to an underwater environment are proposed. Besides, a new marine communication system model was proposed to improve the reliability of the proposed SBMAC method. The scheme minimizes transmission of control frames except for data transmission and various transmission methods and ACK methods can be used together. Simulation models are set indices and analysis of the underwater environment is established to conduct reliable simulations. Consequently, the performance improvement of the proposed method is verified with respect to delay time, data transmission rate, memory utilization, energy efficiency, etc.

Design and Implementation of the Test-bed for Underwater Acoustic Sensor Network Based on ARM9 Processor

Underwater acoustic communication, compared with Wireless Sensor Networks (WSNs) used in terrestrial environment, poses unique challenges due to the harsh underwater environment, such as limited bandwidth capacity, high and variable propagation delays, high bit error rates, and temporary losses connectivity caused by multipath and fading phenomena in spite of using a variety of applications in many areas. In this paper we specify to develop the baseboard using characteristics of ARM9 processor based on low power consumption to enhance the performance, to improve a variety of restrictions. And we describe the process of the underwater communication that demonstrates and designs test-bed of the underwater acoustic sensor network with a similar actual environment.

CCM-UW Security Modes for Low-band Underwater Acoustic Sensor Networks

In this paper, we briefly describe an underwater media access control protocol based on the request to send/clear to send mechanism with security algorithms, which is proposed to provide data confidentiality, authenticity, and replay attack protection. The protocol includes the counter with cipher block chaining-message authentication code (CBC-MAC) for underwater (CCM-UW) mode that is the modified form of the counter with CBC-MAC (CCM*) mode for underwater acoustic communication, based on the advanced encryption standard/agency, research and institute, academy block cipher algorithm. CCM-UW security mechanism is suitable for underwater acoustic sensor networks (UWASNs) and offers six different security levels with different security strength, energy consumption and transmission time. The results in the paper show that the protocol is not impracticable for UWASNs since it is energy efficient and saves transmission time.

Adaptive GTS Allocation Scheme based on IEEE 802.15.4 for Underwater Acoustic Sensor Networks

This paper proposes a new media access control (MAC) protocol, Preamble-MAC (P-MAC). P-MAC is adaptive and dynamic MAC protocol based on Virtual Distance Level (VDL), which is the estimated, accumulated information of channel status and variation obtained through periodically monitoring underwater environment information such as long, unknown propagation delays and low bandwidth for underwater acoustic sensor networks.

Efficient UDD Architecture for Underwater Wireless Acoustic Sensor Network

For the efficient routing environment of Underwater Wireless Sensor Network (UWSN), this paper proposes Underwater Direct-Diffusion (UDD) approach method in consideration of acoustic communications and movement of nodes under ocean environments without using existing RF (Radio Frequency) approach method in the ground-based environments. The data transmission method with the three types of events such as Interest, Gradient, and Reinforce will assure the reliability and maximize energy efficiency of the Interest by following methods; 1) to divide a whole network into top layer, middle layer, and bottom layer to minimize the interference by indiscreet flooding, 2) to prohibit the horizontal query between same layer, and only allow the query between different layers to minimize the energy consumption by flooding transmission 3) to delegate transmission to a non-bridge node in the same layer in case of losing a transmission route by a bridge node’s failure.

Self-organizing P2P overlay network applying dynamic landmark mechanism for contents delivery network

CDN does not calculate connections between infra networks and user networks by increasing physical network. Instead, CDN decentralizes bottlenecked data traffics or contents to main parts of Internet network. By this, an amount of traffics passing through middle-mile of complicated Internet is decreased and CP (contents provider)s server loads are reduced by allocating contents to many distributed servers. In this paper, we proposed an extended Rosary overlay network which is suitable for CDN environment by modification and supplement of Pastry. The proposed Rosary extends Pastry by dividing it into inter-Pastry and intra-Pastry to fit for CDN environment, makes application-level multicasting and adopts semi-hash scheme. By adopting geographic layout technology to proximity neighbor selection technology of Pastry, Rosary node was made to act as landmark server.

Developing an underwater monitoring and alert system for water-borne disease management

Underwater acoustic sensor network (UWASN) can gather the ocean data such as temperature, salinity, pH, turbidity and dissolved oxygen etc. with the help of underwater sensor nodes. Using the underwater surface gateway, underwater sensor nodes forward the ocean data to terrestrial network for the analysis. These techniques can be used to detect the water-borne disease causing areas. Water-borne diseases can spread at certain water conditions. Based on these conditions it is easy to find the water-borne disease causing areas and to alert the health departments. Government healthcare center gets the ocean data from underwater surface gateway via internet and same data can be monitored using big data analysis for water-borne disease management. In this paper we add pre-processing and rule based engine functionalities to the underwater surface gateway to send the alert message to the local healthcare center.

Lightweight Security for Underwater IoT

Becoming IoT era, RF communication on terrestrial network gets faster speed and wide communication coverage. However, because of RF has vulnerability on underwater environment, the underwater acoustic is widely adopting for replacing RF. As a result of efforts, we can suggest ‘underwater IoT’ model and its security challenge by listing UIoT security consideration and comparing underwater security protocols which are presented. Additional, we discuss side channel attack issues.

Security analysis based on Trusted Environment (TRE) of M2M/IoT

The paper considers Machine to Machine (M2M) different access methods are analyses to determine their security aspects. Financial billing system structure consists of architecture, protocol stacks, and communication mechanism. M2M/IoT is widely used in vary industrials energy, transport, industrial communication control, public/private services management, e-health, water, oil and other industries. In this security paper consists of such kind of scams and challenges, TRE mechanism, Pros and Cons of TRE possibility on Finance system.

Lightweight service discovery protocols for constrained environment

Internet of Things (IoT) is becoming increasingly important for todays market and gained a lot of attentions both in academia and industry. IoT can be applied into wide range of application scenarios. In case of constrained environment, for communication, resource-constrained devices are expected to employ the lightweight mechanisms. In order to provide intelligent facilities for constrained IoT devices, energy efficient service discovery mechanism must be designed. In this paper, we address technologies related with constrained environment and provide comprehensive overview of lightweight discovery protocols.