Kyungran Kang

PAMP: Power-Aware Multi-Path Routing Protocol for a Wireless Ad Hoc Network

In a wireless ad hoc network, the limited energy of the nodes is one of major challenges. Many research works are proposed to solve this issue from various aspects. Our work focuses on how to utilize the limited energy of the nodes in data delivery. By combining the concept of multi-path routing and energy reservation, the proposed scheme, PAMP ensures to make a way to delivery packets even though the nodes can not fully satisfy the energy request of the source. PAMP is designed as an extension of the existing AODV by modifying RREQ and RREP management mechanism to handle energy reservation and multiple paths. When compared with other energy-aware routing schemes and AODV, the proposed scheme gives significantly higher data reliability and network lifetime.

Dynamic rate control mechanism for large scale sessions

The network environments of the Internet Multicast session performance are various. The size of Internet community gets bigger and bigger and the variety gets deepening. This paper suggests to build a barrier on every link to restrict the amount of data flowing into the network. Each link has threshold value to specify the requirement for the packets. Multimedia stream is encoded into multiple layers and each layer has its own TTL value. The lowest layer has the largest TTL and the highest layer has the smallest TTL. The threshold is modified according to the traffic of the network and that of the link. It helps the network and the links avoid congestion and make full use of available network capacity.

USS Monitor: A Monitoring System for Collaborative Ubiquitous Computing Environment

This paper introduces a monitoring system, USS monitor for a collaborative ubiquitous computing environment where the applications collaborate to achieve a service goal. We design USS monitor concerning the visualization of the collaboration and the variability of the applications in the main. The monitoring system includes the mechanisms to collect and visualize the state of the member applications for collaboration as well as the resource state of the machines. In addition, concerning the variability of the applications in the ubiquitous computing environment, we design an interaction protocol and the scalable message format between the monitor and the monitored entities. USS monitor is a set of processes and implemented using Java and C. It is operating in the testbed for collaborative ubiquitous computing environment.

Anomaly detection of network-initiated LTE signaling traffic in wireless sensor and actuator networks based on a Hidden semi-Markov Model

LTE signaling attack is a serious threat to a wireless sensor and actuator network whose facilities are dispersed and connected with LTE technology on a large scale, in order to conduct a particular mission. An LTE attacker generates a lot of signaling initiating packets, named wakeup packets, to saturate the LTE networks resources. Existing LTE signaling attack detection schemes are merely based on measuring the mean wakeup packet generation rate. Since resulting from extensive amounts of facilities involved in a normal management process, severe fluctuations of signaling traffic are ordinarily expected in the wireless sensor and actuator network, and those mean-based schemes cannot effectively distinguish between attacks and normal traffic. In this paper, we propose an advanced LTE signaling attack detection scheme based on a Hidden semi-Markov model, which captures the spatialtemporal characteristics of normal wakeup packet generation behavior. Our proposed detector takes the log-likelihood of a nodes wakeup packet generation as the test criterion for normality. Through simulations with various parameter settings, we verified that the proposed scheme effectively distinguishes attacker nodes from normal nodes.

On the Network Coding Delay in Multi-Hop Wireless Networks with Multiple Coding Points

There have been many research works studying the network coding delay, assuming single network coding point or single hop between source and destination. In this paper, we analyze intensively the network coding delay for a multi-hop path between source and destination along which multiple coding points are permitted to reside. Firstly, extending the previous works we develop a numerical form of the network coding delay. Secondly, we present some simulation-based analysis results. The main result is that even though the increase in coding points can contribute to the reduction of network coding delay, the gain increases insignificantly as the number of coding points becomes larger.

Fast Discovery Scheme Using DHT-Like Overlay Network for a Large-Scale DDS

Data distribution service (DDS) is a middleware for data distribution and supports large-scale applications such as Internet service and military systems. However, the reliability and quality of service feature of DDS standard requires an entity to have the complete picture of the participants and endpoints in the network. Thus, the discovery process of the DDS is not scalable and causes noticeable long delay as the number of entities in the network increases. In this paper, we present a scalable fast discovery scheme by exploiting the DHT-like overlay network. Our scheme integrates the participant and endpoint discovery processes and significantly reduces the number of messages for the discovery process. Simulation results indicate that our scheme is faster and requires quite less overhead compared with the simple discovery protocol (SDP) of the DDS standard.

A scalable joint routing and scheduling scheme for large-scale wireless sensor networks

The multihop configuration of a large-scale wireless sensor network enables multiple simultaneous transmissions without interference within the network. Existing time division multiple access (TDMA) scheduling schemes exploit gain based on the assumption that the path is optimally determined by a routing protocol. In contrast, our scheme jointly considers routing and scheduling and introduces several new concepts. We model a large-scale wireless sensor network as a tiered graph relative to its distance from the sink, and introduce the notion of relay graph and relay factor to direct the next-hop candidates toward the sink fairly and efficiently. The sink develops a transmission and reception schedule for the sensor nodes based on the tiered graph search for a set of nodes that can simultaneously transmit and receive. The resulting schedule eventually allows data from each sensor node to be delivered to the sink. We analyze our scheduling algorithm both numerically and by simulation, and we discuss the impact of protocol parameters. Further, we prove that our scheme is scalable to the number of nodes, from the perspectives of mean channel capacity and maximum number of concurrent transmission nodes. Compared with the existing TDMA scheduling schemes, our scheme shows better performance in network throughput, path length, end-to-end delay, and fairness index.

A history of computer networking and the internet in Korea [History of Communications]

This paper briefly describes Internet development in the Republic of Korea (South Korea), which started research and development on computer networking in the late 1970s. Korea became one of the first countries to deploy the Internet in 1982 [1], and organized one of the first global Internet conferences in 1985 [2]. In the late 1990s, Korea put much effort into development of broadband networks, starting from a master plan in 1995. Korea became a world leader with widely available wired and wireless broadband networks. Korea also led in Internet applications including online games, search engines and social networking services. As one of the earlier Internet countries, Korea has been vulnerable to newly arising problems on the Internet such as cybersecurity, net abuse and game addiction. Korea has been trying to solve these problems in collaboration with other leading countries. Korea has also shared its Internet experience with other countries, in particular with developing countries. A book is in preparation on the early history of the Internet in Korea [3] together with another, co-authored with Internet pioneers in other countries, on the early history of the Internet in Asia.

An Inter-Session Opportunistic Network Coding-aware Multipath Routing Protocol

An ad hoc network consists of nodes with limited energy. Therefore, the data transmission can fail abruptly due to lack of energy of transmitting node. A previous work PAMP proposed to build multiple low-energy paths to support stable packet delivery exploiting the nodes with low energy. It has energy-reservation scheme and multi-path selection scheme for stationary wireless ad hoc networks. In this paper, we propose an extended version of PAMP by incorporating network coding opportunity in path selection process. The simulation results show that our proposed scheme shows better packet delivery ratio and lower energy consumption compared with PAMP and a legacy energy-aware multipath routing protocol REAR.

TMRCC: a congestion control mechanism for tree-based many-to-many reliable multicast protocols

Congestion control is a key task in reliable multicast along with error control. However, existing tree-based congestion control schemes such as MTCP[11] and TRAMCC[3] are designed for one-to-many reliable multicast and have some drawbacks when they are used for many-to-many reliable multicast. We propose an efficient congestion control mechanism, TMRCC, for tree-based many-to-many reliable multicast protocols. The proposed scheme is based on the congestion windowing mechanism and a rate controller is used in addition. The feedback for error recovery is exploited for congestion control as well to minimize the overhead at the receivers. The ACK timer and the NACK timers are set dynamically reflecting the network condition changes. The rate regulation algorithm in the proposed scheme is designed to help the flows sharing the same link to achieve the fair share quickly. The performance of the proposed scheme is evaluated using ns-2 [2]. The simulation results show that the proposed scheme outperforms TRAMCC in terms of intra-session fairness and shows good level of responsiveness, TCP-friendliness, and scalability.