• Journal of Advanced Navigation Technology
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• v.12 no.6
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• pp.554-558
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• 2008

In this paper, we show that the SIDMA(Self-organized Time Division Multiple Access) protocol using aviation surveillance data link now, designs to the ICAO DO 9816 documentation sequence. This protocol makes use of the VDL(VHF Data Link) Mode 4 and UAT(Universal Access Transceiver) system's MAC(Media Access Control) layer. We make sure of the simulation result and implementation of STDMA protocol program in accompany with the ICAO documentation sequence. This program operates the slot allocation and reservation with report rate when protocol transmits data and calculates slot address.

• Journal of information and communication convergence engineering
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• v.12 no.1
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• pp.14-18
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• 2014

A recent major development in computer technology is the advent of wearable computer systems. Wearable computer systems employ a wireless universal serial bus (WUSB), which refers to a combination of USB with the WiMedia wireless technical specifications. In this study, we focus on an integrated system of WUSB over wireless body area networks (WBANs) for wireless wearable computer systems. However, current WBAN MACs do not have well-defined quality of service (QoS) mapping and resource allocation mechanisms to support multimedia streams with the requested QoS parameters. To solve this problem, we propose a novel QoS-aware time slot allocation method. The proposed method provides fair and adaptive QoS provisioning to isochronous streams according to current traffic loads and their requested QoS parameters by executing a QoS satisfaction algorithm at the WUSB/WBAN host. The simulation results show that the proposed method improves the efficiency of time slot utilization while maximizing QoS provisioning.

• The Journal of the Acoustical Society of Korea
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• v.20 no.7
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• pp.101-108
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• 2001

In this paper we focus on dynamic reservation slot allocation scheme for supporting QoS of a voice traffic in WATM MAC. Especially, voice traffic is the most important real-time object, and so we propose a new MAC protocol for voice traffic over WATM networks in the multimedia environment. According to the characteristics of voice traffic which is repeatedly in silent state and active state, new protocol allocates reservation slots dynamically with respect to the number of silent voice source of which starting time is stored to the state table in base station (BS). The simulation results show that the proposed protocol has better performance than slotted ALOHA in average access delay, collision rate, better than NC-PRMA(Non Collision Packet Reservation Multiple Access) in band width efficiency, and can provide a certain level of QoS requirement by the given slot assignment even though the number of voice terminals is increased.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.8
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• pp.1567-1576
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• 2015

This paper proposes a reliable real-time data dissemination protocol for mitigating transmission failure of real-time data in WSNs. The re-transmission is well-known for recovery of transmission failure, but this may violate the real-time requirement by transmission delay. To solve this problem, the proposed protocol exploits broadcasting nature and temporal opportunity allocation. In a radio-range of sending node, there may be neighbors satisfying the real-time requirement. The neighbors of specific node could receive data simultaneously by broadcasting, and decide their priority using temporal opportunity allocation method. The method uses time slot and tolerable time. The time slot specifies the priority and transmission deadline for each neighbors, and the tolerable time is the real-time requirement at the sending node. By giving the priority to the node with shorter tolerable time in each slot, we may get more opportunities to forward toward the destination. In other words, even if a node have the longer tolerable time, it still has a chance to forward with the real-time requirement. Simulation results show that the proposed protocol is superior to the existing protocols.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.4
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• pp.468-478
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• 2002

In this paper, we designed a B-WLL MAC(Media Access Control) protocol and validated its operation for implementation of high-speed subscriber networks. Our MAC protocol was designed by SDL using the DAVIC specifications based upon the variable contention/reserved time slot allocation algorithm. For validation of our MAC protocol, Syntax and semantic error check were performed by the Simulation Builder of ObjectGeode and the MAC(Message Sequence Chart) respectively. The validation results showed that our B-WLL MAC protocol is working correctly and may successfully support B-WLL services.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.423-425
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• 2007

In this paper, Medium Access Control(MAC) protocol designed for Wireless Body area Sensor Network(Bio-MAC) is proposed, Because in WBSN, the number of node is limited and each node has different characteristics. Also, reliability in transmitting vital data sensed at each node and periodic transmission should be considered so that general MAC protocol cannot satisfy such requirements of biomedical sensors in WBSN. Bio-MAC aims at optimal MAC protocol in WBSN. For this, Bio-MAC used Pattern -SuperFrame, which modified IEE E 802.15.4-based SuperFrame structurely. Bio-MAC based on TDMA uses Medium Access-priority and Pattern eXchange -Beacon method for dynamic slot allocation by considering critical sensing data or power consumption level of sensor no de etc. Also, because of the least delay time. Bio-MAC is suitable in the periodic transmission of vital signal data. The simulation results demonstrate that a efficient performance in WBSN can be achieved through the proposed Bio-MAC.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.2
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• pp.59-68
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• 1996

In this paper, we propose two types of WDMA protocol for multi-wavelength optical networks that have a dedicated control channel. Protocol type I is designed for the case that the number of nimislots is less than the number of nodes (La${\ge}$M). Proposed protocols employ the aging scheme to guarantee a fairness in the process of channel allocation. The perfomrance of proposed protocols are evaluated in terms of throughput and delay with variations in offered load. Simulation results show that the proposed protocols have superior performance to conventional protocols.

• Journal of Digital Contents Society
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• v.2 no.1
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• pp.93-102
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• 2001

In this paper we proposed a wireless MAC Protocol called DTDD/PS (Dynamic Time Division Duplex using Poll/Select scheme), and throughput performance is evaluated using computer simulation. Simulation results indicate that the proposed DTDD/PS protocol increases the limitation of allowable loads that guarantee duality of services by dynamic allocation of slot based on the system status. Also the proposed protocol is shown to maintain stable throughput even in the case of traffic variations.

• The KIPS Transactions:PartC
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• v.9C no.4
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• pp.543-550
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• 2002

This paper proposes the dynamic slot allocation method for real-time VBR (rt-VBR) services in wireless ATM networks. The proposed method is characterized by a contention-based mechanism of the reservation request, a contention-free polling scheme for transferring the dynamic parameters. The base station scheduler allocates a dynamic parameter minislot to the wireless terminal for transferring the residual lifetime and the number of requesting slots as the dynamic parameters. The scheduling algorithm uses a priority scheme based on the maximum cell transfer delay parameter. Based on the received dynamic parameters, the scheduler allocates the uplink slots to the wireless terminal with the most stringent delay requirement. The simulation results show that the proposed method guarantee the delay constraint of rt-VBR services along with its cell loss rate significantly reduced.

• Journal of electromagnetic engineering and science
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• v.12 no.1
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• pp.1-7
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• 2012

In this paper, we investigated the throughput of a cognitive radio network where two primary frequency channels (PCs) are sensed and opportunistically accessed by N secondary users. The sharing sensing member (SSM) protocol is introduced to sense both PCs simultaneously. According to the SSM protocol, N SUs (Secondary User) are divided into two groups, which allows for the simultaneous sensing of two PCs. With a frame structure, after determining whether the PCs are idle or active during a sensing slot, the SUs may use the remaining time to transmit their own data. The throughput of the network is formulated as a convex optimization problem. We then evaluated an iterative algorithm to allocate the optimal sensing time, fusion rule and the number of members in each group. The computer simulation and numerical results show that the proposed optimal allocation improves the throughput of the SU under a misdetection constraint to protect the PCs. If not, its initial date of receipt shall be nullified.