• Title/Summary/Keyword: TDMA

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Performance Analysis of Dynamic TDMA and Fixed TDMA in Tactical Data Link (전술데이터링크의 동적 TDMA와 정적 TDMA 성능 분석)

  • Lee, Jong-Kwan
    • Journal of the Korea Institute of Military Science and Technology
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    • v.21 no.4
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    • pp.489-496
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    • 2018
  • In this paper, a performance comparison of dynamic TDMA and fixed TDMA in tactical data link system is conducted. The performance metric include: delay, queue size and system throughput. To perform comparison of two TDMA schemes, we adopt the modified M/D/1 queueing model. Computer simulation is also performed to verify conducted analytical results.

A Study on the Performance of MAC Protocols for High-Speed Mobile Data Services (이동 고속데이타 서비스용 MAC계층 프로토콜의 성능연구)

  • 김태규;조동호
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.9
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    • pp.1730-1738
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    • 1994
  • Broadband code division multiple access(B-CDMA)previously proposed for personal communication services(PCS) is not suitable for high-speed data services with large variations in speed, because it is designed only for low-speed voice calls with small variations in speed. Meanwhile, hybrid intra-cell TDMA/inter-cell CDMA(Hybrid TDMA/CDMA) recently proposed could accomodate high-speed services easily because of its internal use of the TDMA scheme, but there would be much inefficiency in treating variable bit rate services due to the intrinsic properties of TDMA transmission scheme, In this paper, a media access control(MAC) protocol, called Resevation TDMA/CDMA, which uses a reservation scheme similar to the one in the packet reservation multiple access(PRMA) protocol to compensate for these shortcomings is proposed. In addition, the performance of this protocol is analyzed and compared with conventional protocols by computer simulation. According to the simulation results, it has been shown that the proposed Reservation TDMA/CDMA scheme could support various transmission rates of user data traffics easily, and it could utilize the variations of the treansmission rates in each active call more efficiently.

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A Study on Improvement of QoS through Analyzing Transmission Characteristics of TDMA Noise in the GSM Mobile Set (GSM 휴대폰 TDMA 잡음 전달 특성 분석을 통한 통화 품질 개선에 관한 연구)

  • Ha, Jeung-Uk;Oh, Tae-Hoon;Kang, Jin-Seok;Yoon, Young-Joong
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.19 no.4
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    • pp.470-476
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    • 2008
  • In this paper, we describe the cause of TDMA noise and distinction method of TDMA noise source in a GSM mobile phone. The causes of TDMA noise are composed of RF(Radio Frequency) energy coupling and low frequency energy coupling by burst ripple. We propose the distinction method of TDMA noise source from output(TDMA noise measurement) and frequency response of a system(audio path). Especially we propose a method of insertion loss($S_{21}$) analysis and the improvement method for RF energy coupling. Capacitor(40 pF) is a solution to reduce RF energy coupling and therefore TDMA noise was reduced by 10 dB.

Design and Implementation of HomeTDMA: a TDMA Protocol for Home Networks

  • Casaquite, Reizel;Hwang, Won-Joo
    • Journal of Korea Multimedia Society
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    • v.10 no.12
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    • pp.1612-1621
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    • 2007
  • In this paper, we introduced our designed TDMA (Time Division Multiple Access) based MAC (Medium Access Control) protocol for Home Networks called HomeTDMA. We have implemented and tested it in a test bed using crossbow motes and TinyOS. We also have compared HomeTDMA and CSMA (Carrier Sense Multiple Access) in terms of space and time complexity, channel access time, delivery success ratio, and throughput. Based on our results, HomeTDMA has an advantage over CSMA on channel access time, throughput and delivery success ratioIn the case of complexity, HomeTDMA is more complex compared to CSMA. Thus, CSMA is more appropriate in wireless sensor networks (WSNs) where memory, energy, and throughput are important parameters to be considered. However, HomeTDMA has a natural advantage of collision free medium access and is very promising for home networks where a reliable transmission or data transfer and congestion control is highly preferred.

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Throughput Analysis of ASO-TDMA in Multi-hop Maritime Communication Network (다중-홉 선박 통신 네트워크를 위한 애드혹 자율 구성 TDMA 방식의 수율 성능 분석)

  • Cho, Kumin;Yun, Changho;Kang, Chung G.
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37B no.9
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    • pp.741-749
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    • 2012
  • Ad Hoc Self-Organizing TDMA (ASO-TDMA) has been proposed as a specification to support the multi-hop data communication service for ships over VHF band. It allows for organizing a multi-hop ad-hoc network in a distributed manner by sharing the radio resources among the ships navigating along the route. In this paper, Markov chain analysis is given to provide the average throughput performance for ASO-TDMA protocol Furthermore, the analytical results are verified with computer simulation, which shows that there exists the optimal transmission rate to maximize the average throughput as the subframe size and the number of ships are varying in each hop region.

An Improved Depth-Based TDMA Scheduling Algorithm for Industrial WSNs to Reduce End-to-end Delay (산업 무선 센서 네트워크에서 종단 간 지연시간 감소를 위한 향상된 깊이 기반 TDMA 스케줄링 개선 기법)

  • Lee, Hwakyung;Chung, Sang-Hwa;Jung, Ik-Joo
    • Journal of KIISE
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    • v.42 no.4
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    • pp.530-540
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    • 2015
  • Industrial WSNs need great performance and reliable communication. In industrial WSNs, cluster structure reduces the cost to form a network, and the reservation-based MAC is a more powerful and reliable protocol than the contention-based MAC. Depth-based TDMA assigns time slots to each sensor node in a cluster-based network and it works in a distributed manner. DB-TDMA is a type of depth-based TDMA and guarantees scalability and energy efficiency. However, it cannot allocate time slots in parallel and cannot perfectly avoid a collision because each node does not know the total network information. In this paper, we suggest an improved distributed algorithm to reduce the end-to-end delay of DB-TDMA, and the proposed algorithm is compared with DRAND and DB-TDMA.

Mesh Routing Algorithm for TDMA Based Low-power and Ad-hoc Networks (TDMA 기반 저전력 애드혹 네트워크를 위한 메쉬 라우팅 알고리즘)

  • Hwang, Soyoung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.8
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    • pp.1955-1960
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    • 2014
  • Many routing protocols have been proposed for low-power and ad-hoc networks to deliver command or data among nodes and recently, various researches are carried out about networking scheme considering reliability and scalability. In low-power networking technology, the performance of network layer is closely connected with the operation of data link layer and mesh routing mechanisms based on TDMA MAC are considered for reliability and scalability. This paper proposes mesh routing algorithm utilizing the characteristics of TDMA MAC and topological addressing in TDMA based low-power and ad-hoc networks and implementation results are presented.

Inter-Transmitter Distance-Based Guard Time Control Scheme in Airborne Tactical TDMA Networks with Long Propagation Delay (전파 지연이 긴 공중 전술 TDMA 네트워크에서 송신자 간 거리 기반 보호 시간 제어 기법)

  • Baek, Hoki;Lim, Jaesung;Koo, Jayeul;Oh, Ilhyuk
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37C no.11
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    • pp.1104-1111
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    • 2012
  • Airborne tactical networks is used to air-to-air or air-to-ground operation and have a large propagation delay. All nodes share the data by using TDMA-based broadcasting. In airborne tactical networks, each time slot needs the guard time to ensure the broadcasting because the collisions occur due to the large propagation delay. However, the channel utilization of the networks can be greatly degraded due to the waste of guard time. In this paper, we propose Inter-Transmitter Distance-Based TDMA (ID-TDMA) scheme which ensures the broadcasting while improving the channel utilization by reducing the guard time with the inter-transmitter distance information. The proposed scheme shows the effectiveness through the performance evaluation.

Design and Implementation of Real Time AGC for Satellite TDMA Communication Systems (위성 시분할다중접속 통신시스템을 위한 실시간 자동이득제어기 설계 및 구현)

  • Lee, Huisoo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38B no.4
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    • pp.298-304
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    • 2013
  • Channel attenuation must be taken into account when designing Time Division Multiple Access(TDMA) communication systems. In addition, Automatic Gain Control (ACG) is a requirement in satellite communication systems in order to form a stable network regardless of rapidly changes in channel environment. In this study, we present an AGC with possible real-time application to time slots in satellite TDMA communication systems. A satellite TDMA system was designed and implemented in order to test the performance of the proposed real-time AGC, and the system's BER (Bit Error Rate) was found by applying the proposed AGC algorithm. These results can be expected to be of high value in improving the stability of satellite TDMA communication systems in the future.

Performance Analysis of Co-Existence of DS-CDMA and TDMA System by Using Complex Multirate Filter Bank in Land Mobile Channel (육상 이동통신 채널에서 복소 다중비율 필터뱅크를 채용한 DS-CDMA/TDMA 공존 시스템의 성능 분석)

  • 우병훈;강희조
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.11 no.1
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    • pp.1-7
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    • 2000
  • In this paper, we proposed a complex multirate filter bank(CMRFB) based adaptive notch filtering technique to solve the co-existence narrowband interference problem of DS-CDMA and TDMA systems. We have discussed error performance of co-existence of DS-CDMA and TDMA system by using complex multirate filter bank in land mobile channel and computer simulation results show that the proposed scheme can eliminate the narrowband interference(TDMA signals) effectively.

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