Young C. Park

Terrestrial communications system design and MOE factors

Abstract An area network contains significant redundancy and can sustain considerable damage, or cope with substantial movement, because of the alternative routes available. In this paper we examine some measure of effectiveness (MOE) factors for Army Terrestrial Communications System (TCS) in detail: mobility, security/survivability, system availability, grade of service (GOS), design flexibility, interoperability, reliability, maintainability, cost effectiveness, and enhanceability. We also shall analyze the average link delay versus network size and arrival rate which is related to GOS factors. We believe that the flood search routing algorithm provides survivability and is a viable option for providing a reliable routing framework in Army Terrestrial Communications System.

Performance Improvement of Flooding Algorithm in Highly Mobile Networks

In this paper we propose a modified flooding algorithm for highly mobile networks. This scheme minimizes the call set-up time and does not have to maintain routing tables. Because of its significant drawbacks with respect to the network efficiency, it has not found widespread applications. Using the minimum first-derivative length (MFDL) path, we improve the blocking probability performance of a circuit-switched grid network without increasing the call set-up time and processor loading of the algorithm.

An analysis of s-t reliability for wireless networks under outage conditions

The ATN (Army Tactical Network) system, which provides communications for mobile users, uses a flood search routing algorithm to locate a path from the caller to the called party, inherently providing alternate routing around outages, and thus providing a survivability. The network performance measures are are functions of reliabilities of the network elements. In this paper we analyze s-t reliability for wireless which uses a flood search routing algorithm with a frequently called list (FCL) to route calls and packets, under node or link outage. We evaluate connectivity and reliability of calls as performance measures. The flood search algorithm performs very well in routing traffic around disabled links and nodes.

Study of M-learning system for middle school

Wireless-enabled laptops make it possible for students to use their time more efficiently, access databases and information from the Internet. The ubiquitous learning environment is suitable for mobile learning (m-learning). This paper discusses the characteristics and requirements of m-learning based on ubiquitous computing. And we suggest the feasible design of m-learning system and describe the case study of music education using PDA (personal digital assistant) devices for middle school in Korea.

Design considerations of terrestrial communications system

We study design considerations, measure of effectiveness (MOE) factors, for tactical communications system. Terrestrial communications system (TCS) architecture for army is described and the link delay performance as a grade of service (GOS) factor is analyzed. One can see that flood search routing algorithm in mesh networks is well suited for tactical communications network and survivability requirements.

Evaluating the Performance of Integrated Voice and Data Mobile Networks

In this paper we propose an integrated ATN (Army tactical network) with cellular CDMA 2000 system in order to improve ATNs overall routing performance and we also propose a route optimization technique for the multiple commodities flow problem using a modified flood search algorithm in a hybrid-switched network under dynamic traffic and topological conditions. The modified flood search algorithm uses the FDL (first derivative length) path which improves the blocking and time delay performances

Study of the terminal-pair reliability in grid networks

In this paper, we study the terminal-pair reliability in grid networks. An area switched tactical communication system such as ATN (Army Tactical Network) involve large number of nodes, and of links. The resulting huge number of possible combinations of node and link failures makes it difficult to perform quantitative analysis for system survivability assessments in terms of multi-hop connectivity, under jamming and physical attacks. We suggest an ATN Simulation Model (ATNSM) to overcome this difficulty for enumerating multi-hop routing successes to develop a lower bound on connectivity. The analysis techniques were exercised on an example ATN area coverage network model with 7×5 grid nodes under stress conditions.