• Title/Summary/Keyword: Anti-Collision

Search Result 231, Processing Time 0.019 seconds

A Design of Anti-Aircraft Artillery Model for the Surface-to-Air Virtual Engagement (지대공 교전모의를 위한 대공포 모델 설계)

  • Yang, Chang-Deok;Yang, Ji-Youn;Kim, Cheon-Young;Hong, Young-Seok;Reu, Tae-Kyu
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.14 no.4
    • /
    • pp.639-647
    • /
    • 2011
  • In this paper, we have designed the Anti-Aircraft Artillery(AAA) model for the surface-to-air virtual engagement. The AAA model for the virtual combat simulation needs to detect the present target and estimate the target flight trajectory to find the aiming point. To find collision point of projectile fired from the artillery with the moving air target, we have presented the estimating technique for artillery aiming point. And we have analyzed the target probability of kill using Calton Hit function. Anti-air threat envelops are presented when the target velocity, position and the arrangement of four AAA are varying. Then we have compared the analyzed result using developed model with AEM model of MSA program.

A Hybrid Anti-Collision Protocol using Bit Change Sensing Unit in RFID System (RFID 시스템에서 비트변화감지를 이용한 하이브리드 충돌 방지 프로토콜)

  • Kim, Jeong-Hwan;Kim, Young-Tae;Park, Yong-Soo;Ahn, Kwang-Seon
    • Journal of Internet Computing and Services
    • /
    • v.10 no.2
    • /
    • pp.133-141
    • /
    • 2009
  • A tag collision problem occurs when many tags are placed in a interrogation zone in RFID system. A tag collision problem is one of core issues and various protocols have been proposed to solve the collision problems. Generally tree-based protocols generate unique prefixes and identify tags with them as quick as possible. In this paper, we propose the QT-BCS protocol which decreases the identification time by reducing the number of query-response. The QT-BCS protocol makes a prefixes using time slot and bit change sensing unit. This protocol compares the current bit of tags until the current bit is differ from the previous one. When this occurs, all of the bits scanned so far are transferred to slot-0 and slot-1 depending on the first bit value in Reader. Consequently, this method can reduce the number of queries by tracing prefixes easily. Simulation result shows QT-BCS is more efficient in identifying tags than Query Tree and 4-ary Query Tree protocol.

  • PDF

EPCglobal Gen 2 Tag Identification Performance Analysis Modifying the C model in the Q Algorithm (EPCglobal Gen 2 Q 알고리즘에서 C 모델에 따른 태그 인식 성능 평가)

  • Park, Jong-Myung;Cho, Sung-Ho
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.34 no.12B
    • /
    • pp.1444-1451
    • /
    • 2009
  • This paper first proposes diverse C determining models in the Q algorithm which is proposed in the EPCglobal C1 Gen 2 standard and then compares and analyzes its performance. EPCglobal C1 Gen 2 standard proposes the slot-count (Q) selection algorithm for multiple tag identification environment, but there is no such definition for the C value which modifies the Q value depending on collision or no reply. During the tag anti-collision process, the Q algorithm adds C to the Q when there is a collision and reduces the Q by C when there is no reply. The modified Q value updates new slot-counts for tags which determines the tag identification speed, so the C value is an important factor. However, many researches only intend to increase the tag identification speed by proposing a new method or modifying the Q algorithm without any research about the C value. This paper suggests diverse C models which satisfies the EPCglobal C1 Gen 2 and analyzes their performance in the multi tag identification environment. The result of this paper can be used as an index for future researches on EPCglobal C1 Gen 2 C models and multiple tag identification performance.

Adaptive RFID anti-collision scheme using collision information and m-bit identification (충돌 정보와 m-bit인식을 이용한 적응형 RFID 충돌 방지 기법)

  • Lee, Je-Yul;Shin, Jongmin;Yang, Dongmin
    • Journal of Internet Computing and Services
    • /
    • v.14 no.5
    • /
    • pp.1-10
    • /
    • 2013
  • RFID(Radio Frequency Identification) system is non-contact identification technology. A basic RFID system consists of a reader, and a set of tags. RFID tags can be divided into active and passive tags. Active tags with power source allows their own operation execution and passive tags are small and low-cost. So passive tags are more suitable for distribution industry than active tags. A reader processes the information receiving from tags. RFID system achieves a fast identification of multiple tags using radio frequency. RFID systems has been applied into a variety of fields such as distribution, logistics, transportation, inventory management, access control, finance and etc. To encourage the introduction of RFID systems, several problems (price, size, power consumption, security) should be resolved. In this paper, we proposed an algorithm to significantly alleviate the collision problem caused by simultaneous responses of multiple tags. In the RFID systems, in anti-collision schemes, there are three methods: probabilistic, deterministic, and hybrid. In this paper, we introduce ALOHA-based protocol as a probabilistic method, and Tree-based protocol as a deterministic one. In Aloha-based protocols, time is divided into multiple slots. Tags randomly select their own IDs and transmit it. But Aloha-based protocol cannot guarantee that all tags are identified because they are probabilistic methods. In contrast, Tree-based protocols guarantee that a reader identifies all tags within the transmission range of the reader. In Tree-based protocols, a reader sends a query, and tags respond it with their own IDs. When a reader sends a query and two or more tags respond, a collision occurs. Then the reader makes and sends a new query. Frequent collisions make the identification performance degrade. Therefore, to identify tags quickly, it is necessary to reduce collisions efficiently. Each RFID tag has an ID of 96bit EPC(Electronic Product Code). The tags in a company or manufacturer have similar tag IDs with the same prefix. Unnecessary collisions occur while identifying multiple tags using Query Tree protocol. It results in growth of query-responses and idle time, which the identification time significantly increases. To solve this problem, Collision Tree protocol and M-ary Query Tree protocol have been proposed. However, in Collision Tree protocol and Query Tree protocol, only one bit is identified during one query-response. And, when similar tag IDs exist, M-ary Query Tree Protocol generates unnecessary query-responses. In this paper, we propose Adaptive M-ary Query Tree protocol that improves the identification performance using m-bit recognition, collision information of tag IDs, and prediction technique. We compare our proposed scheme with other Tree-based protocols under the same conditions. We show that our proposed scheme outperforms others in terms of identification time and identification efficiency.

On Facilitating RFID Tag Read Processes via a Simple Parameter Estimation

  • Park, Young-Jae;Kim, Young-Beom
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.37 no.1C
    • /
    • pp.38-44
    • /
    • 2012
  • In this paper, we first formulate an optimal design problem for RFID tag identification processes and then propose a simplified estimation method for determining optimal frame sizes and termination time under an independence assumption. Through computer simulations we show that the proposed scheme outperforms Vogt's scheme in terms of identification delay.

Performance Improvement of Anti-collision Algorithm for RFID Protocol and Algorithm Comparison (RFID 프로토콜의 충돌방지 알고리즘의 성능 개선과 알고리즘 비교)

  • Lim, Jung-Hyun;Kim, Ji-Yoon;Jwa, Jeong-Woo;Yang, Doo-Yeong
    • Journal of the Institute of Electronics Engineers of Korea CI
    • /
    • v.44 no.6
    • /
    • pp.51-61
    • /
    • 2007
  • In this paper, Air-interface protocols of ISO 18000-6 Types and EPCglobal Classes applied to RFID system in UHF band are analyzed, and those anticollision algorithms are realized. Also, the each algorithm which improves the performance of standard protocol is proposed, and the performance is compared when clock period of link timing is a identical condition on $12.5{\mu}s$. As the result, when 500 tags exist simultaneously inside reader interrogation zone, the tag recognition performance of a standard protocol is better in preceding order of Class-1 Generation-1, Type B, Type A, Class-0 and Class-1 Generation-2. And also the performance of improved protocol is better in ascending order of Type B, Type A, Class-1 Generation-1, Class-0 and Class-1 Generation-2. Therefore, performance of tag recognition remarkably depends on the regulated clock period in the protocol and link timing between a reader and a tag.

Performance Analysis of Anti-collision Algorithm for an RFID(ISO 18000-6) Protocol (RFID 프로토콜(ISO 18000-6)에서의 충돌방지 알고리즘 성능 분석)

  • Kang, Bong-Soo;Lim, Jung-Hyun;Kim, Heung-Soo;Yang, Doo-Yeong
    • Journal of the Institute of Electronics Engineers of Korea CI
    • /
    • v.44 no.5
    • /
    • pp.20-27
    • /
    • 2007
  • In this paper, Air-interface protocols of ISO 18000-6 Type A and B applied to RFID system in UHF band are analyzed, and those algorithms are realized. Also, the improved anticollision algorithms for the Type A and B of ISO 18000-6 protocol are proposed and the performances are compared. As the results, reduction ratio of total tag recognition time of the improved ISO 18000-6 Type A algorithm is 35.2 % for 100 tags and 24.3% for 1000 tags with respect to standard algorithm, respectively. And the reduction ratio of the improved ISO 18000-6 Type B algorithm is 6.0% for 100 tags and 6.6% for 1000 tags. Therefore, the improved anticollision algorithm proposed in this paper is the advanced method improving the performance of tag recognition in the RFID system.

Enhanced bit-by-bit binary tree Algorithm in Ubiquitous ID System (Ubiquitous ID 시스템에서의 Enhanced bit-by-bit 이진 트리 알고리즘)

  • 최호승;김재현
    • Journal of the Institute of Electronics Engineers of Korea TC
    • /
    • v.41 no.8
    • /
    • pp.55-62
    • /
    • 2004
  • This paper proposes and analyzes two anti-collision algorithms in Ubiquitous ID system. We mathematically compares the performance of the proposed algorithms with that of binary search algorithm slotted binary tree algorithm using time slot, and bit-by-bit binary tree algorithm proposed by Auto-ID center. We also validated analytic results using OPNET simulation. Based on analytic result comparing the proposed Modified bit-by-bit binary tree algorithm with bit-by-bit binary tree algorithm which is the best of existing algorithms, the performance of Modified bit-by-bit binary tree algorithm is about 5% higher when the number of tags is 20, and 100% higher when the number of tags is 200. Furthermore, the performance of proposed Enhanced bit-by-bit binary tree algorithm is about 335% and 145% higher than Modified bit-by-bit binary tree algorithm for 20 and 200 tags respectively.

Improvement of Tag Collection Performance for Active RFID Systems (능동형 RFID 시스템을 위한 태그 수집 성능 개선)

  • Yoon, Won-Ju;Chung, Sang-Hwa;Moon, Young-Sik
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.33 no.7B
    • /
    • pp.518-527
    • /
    • 2008
  • Tag collection is one of the major functions in Radio Frequency Identification (RFID) systems. IS0/IEC 18000-7 defines the tag collection algorithm using the anti-collision algorithm, based on the framed slotted ALOHA for active RFID systems. However, it has inefficiency problems that reduce tag collection performance by deciding non-optimum slot size or using point-to-point commands to put collected tags to sleep. In this paper, we propose two mechanisms to overcome the inefficiency problems and improve tag collection performance: 1) a new slot size decision mechanism to allow the reader to choose the optimum slot size flexibly and 2) a broadcast-based sleep mechanism to put collected tags to sleep effectively. We also implemented an active RFID system, composed of an active RFID reader and multiple tags, and the reader is designed to maximize tag collection performance when the proposed mechanisms are applied. In experiments, we evaluated the tag collection performance using one reader and 50 tags in the real-world environment. The experimental results show that when two mechanisms are applied and the initial number of slots is chosen appropriately, the performance of the proposed tag collection algorithm is greatly enhanced, compared with that of the standard.