• Journal of the Institute of Electronics and Information Engineers
• /
• v.50 no.1
• /
• pp.51-63
• /
• 2013

Recently with base apply MANET with the application for the service discovery and delivery which are various techniques are being proposed the result of such MANET base research techniques from actual inside. This dissertation proposes T-Chord(Trustworthy-based Chord) Ring system for MANET to guarantees from such requirements. T-Chord Ring system in order to manage Efficiently the services which the mobile nodes provide is the service discovery system which uses P2P overlay network Technique in mobile environment. The system which is proposed MANET communications in order to accomplish a service discovery operation with physical network class and logical network class will be able to minimize problems from about MANET service discoveries, and uses the dispersive hash table technique for a service discovery and effectiveness of service discovery improves and will be able to guarantee the expandability of network size. The mobile nodes(mobile device) have a mobility from MANET and operate with service request node, service provide node and service transmit node. The mobile nodes will be able to elect cluster header using Trustworthy that was evaluated service request, provision and delivery in each other. The system which is proposed a service discovery and a delivery efficiently will compose the cluster head which will grow of P2P overlay networks and will be able to accomplish. The system which proposes from dissertation is composed of Trustworthy evaluations of MANET mobile nodes, service information collection which is dispersed and P2P overlay networks that composed of Chord algorithm modules which provide O(Log N) efficiencies. The system comparison evaluation analyzes an efficiency from the expandability side of effectiveness and the network of service discovery technique and the service discovery message over head, service discovery and delivery of former times and service discovery and delivery is excellent gives proof from MANET.

• Korean Management Science Review
• /
• v.11 no.3
• /
• pp.103-128
• /
• 1994

Due to the trend of evolution toward a broadband communication network with fiber-optics, the design and operation of fiber-optic network have been received a great deal of research attention recently. Furthermore, even a single fiber link failure in the network may result in severe service loss. Thus, the network survivability becomes an importantissue in planning and designing the network. This survey is on modelling of various fiber-optic subscriber loop network(FSLN) design problems, which are essential ones for providing broadband communication services and B-ISDN services. Models are classified and investigated as either conventional decomposition-iteration approach or integrated design method. To build survivable networks, SHR models are also suggested by ring control schemes. The result of this study will be effectively applied to build a design model for FSLN in the practical applications.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.6 no.8
• /
• pp.1216-1222
• /
• 2002

In this study, we suggest structural plans for constructing local network economically and optimal broad local network coincided with regional characteristics in building broad local network - the most important factor in constructing broadband superspeed service digital network giving the consideration to broadband multimedia service unfolded in the future. For the purpose of constructing optimal superspeed local network, we made comparative study of the topology types of star and ring in various conditions from a economical point of view per node and with the transmission distance.

• Proceedings of the KIEE Conference
• /
• 1988.07a
• /
• pp.926-929
• /
• 1988

In this paper, the implementation of NIU (Network Interface Unit) for Token Passing Bus network is studied. The network is based on the IEEE 802.4 standard, which is the basis of MAP. IBM-PC is chosen as host station. The structure of the network and NIU is investigated and the implementation is illustrated. The logical ring constructed following the standard. Transmission and reception of data are tested. The experimental results are referred.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.28B no.5
• /
• pp.404-410
• /
• 1991

In this paper,a network interface unit of token-passing bus network and its driving software are implemented based on Mini-MAP. This network interface unit performs the function of MAC layer which is responsible for transmission and reception of frames as well as the management of logical ring. The driving software performs the management of data buffer and the report of errors, if ocoured, to the higher layer. Motorola MC68824 of is used as a TBC(Token Bus Controller) and Intel80186 as a CPU for network interface unit. The operation of network interface unit is verified by self-test which checks the functioning of TBC and CPU. In addition each module of driving software is tested to check the functions regarding transmission and reception of frames.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.9B
• /
• pp.581-590
• /
• 2005

The IEEE 802.17 Resilient Packet Ring Working Group develops standards to support the development and deployment of Resilient Packet Ring networks in Local, Metropolitan, and Wide Area Networks for resilient and efficient transfer of data Packets at rates scalable to many gigabits Per second. It was known that the fairness algorithm of the IEEE 802.17 Resilient Packet Ring suffers from throughput degradation under an unbalanced overload. This Paper proposes a congestion release advertisement method to improve this throughput degradation and discusses its performance. Under the proposed method, a congested node decides whether its congestion is released or not. If released, it advertises the congestion release to upstream nodes, and then upstream nodes transmit their traffic without uy regulation. The proposed method is compatible with the legacy fairness algorithm.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.26 no.9
• /
• pp.814-820
• /
• 2015

In this paper, A high selective dual-band bandpass filter was proposed using a dual-mode ring resonator with two short-circuited stubs. For dual-mode resonance, the ring resonator is directly connected with non-orthogonal feed-lines via coupling capacitors. Two short-circuited stubs which are unequal lengths are simultaneously placed at two corners along the two symmetry plane of the ring resonator in order to obtain dual-band responses. Because the feeding angle perturbated ring resonator of the proposed dual-band bandpass filter has the symmetrical structure, Even/Odd mode analysis can be well applied to extract the scattering parameters and transmission zero frequencies. The proposed dual-band bandpass filter was designed and fabricated for WLAN(Wireless Local Area Network) application of IEEE 802.11n standard. The measured results showed a good agreement with the simulation results, and it should be well applied not only for WLAN applications but also for any other communication systems.

• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.1735-1740
• /
• 2007

Communication network in KTX (Korea Train eXpress), the express train system, has to transmit status variables periodically within tens of seconds and real-time control informations which has short reply like status transition or alarm. KTX uses $Tornad^*$ (TOken Ring Network Alsthom Device) network for this purpose. This network can send and receive messages which enable express train applications embedded in intelligence boards to communicate by itself. Layer 1, 2 of $Tornad^*$ is implemented with differential manchester encoding and IEEE 802.4 standard(token bus standard) respectively. To implement layer 1 and 2, we implemented twisted pair modem using FPGA for layer 1 and used MC68824 from Motorola for layer 2. MC68824 bus arbitration and memory controller is implemented using CPLD.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.16 no.6
• /
• pp.247-251
• /
• 2021

We propose a protocol for Ethernet-based industrial real-time communication networks. In the protocol, the master periodically transmits control frames to all slaves, and the ring-type network topology is selected to achieve high-speed transmission speed. The proposed protocol is implemented in the form of both firmware and Linux kernel modules. To improve the transmission speed, the MAC address table is disabled in the firmware implementation, and the NAPI function of the Ethernet driver is removed in the Linux kernel module implementation. A network experiment environment is built with four ARM processor-based embedded systems and network operation experiments are performed for various frame sizes. From the experimental results, it is verified that the proposed protocol normally operates, and the firmware implementation shows better transmission speed than the Linux kernel module implementation.

• Journal of Korean Society of Transportation
• /
• v.25 no.5
• /
• pp.101-109
• /
• 2007

Two variations of toll roads exist: mainline toll plazas and entry/exit tolls. On a mainline toll system(open toll scheme), all vehicles stop at various locations along the highway to pay a toll. While this may save money from the lack of need to construct tolls at every exit, it can cause lots of traffic congestion, and drivers could evade tolls by going around them. With entry/exit tolls, vehicles collect a ticket when entering the highway, which displays the fares it will pay when it exits, increasing in cost for distance travelled. Upon exit, the driver will pay the amount listed for the given exit. The pressures on the Seoul ring roadway network have been changing over time. In the past, the emphasis was on mobility and maintenance of the road network to provide an efficient transportation network, but recently, road use has outstripped the network's ability to extend and expand the road network and hence the policy emphasis has moved towards reducing free riders rather than mitigating its effects. In addition to this pressure is an incidental pressure, which argues that provision of free ride segments generates further traffic in isolation of other factors. This paper is examining policies to reduce the burden of traffic congestion in Seoul ring roadway which is used open toll scheme for decades. One key mechanism to achieve this policy aim is automatic charging mechanism on freeway, but if a nation-wide electronic toll collection is to be implemented successfully, there are a number of prerequisites which must be place.