• Title/Summary/Keyword: Blocking Probability

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Erlang Capacity and Call Blocking Probability of CDMA Hierarchical Cellular Systems with Soft Handoff (소프트 핸드오프를 갖는 CDMA 계층구조 셀룰러 시스템의 Erlang 용량과 호 차단확률)

  • Seong, Bong-Hun;O, Hyeon-Seok;Han, Jae-Chung
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.49 no.8
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    • pp.481-490
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    • 2000
  • This paper analyzes interference power, Erlang capacity, the number of handoff occurrences, and call blocking probability with respect to the cell radius, the soft handoff region, and the mobile's velocity in a CDMA hierarchical cellular system. The microcell cellular system has the higher Erlang capacity than the macrocell cellular system. However, the microcell cellular system, which has a high system capacity through frequency reuse has the call blocking probability higher than macrocell cellular system. Also the interference power and the call blocking probability are decreased with the operation of soft handoff. Therefore, this paper presents the optimization of soft handoff region so as to maximize system's Erlang capacity with the low the call blocking probability according to mobile's velocity in the CDMA hierarchial cellular system.

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A Channel Assignment Scheme Using Power Allocation Concept for CDMA Cellular System (CDMA 셀룰러 시스템에서 전력할당개념을 이용한 채널할당기법)

  • Lee, Dong-Myung;Jun, Moon-Seog
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.3
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    • pp.692-698
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    • 1999
  • In this paper, we proposed the channel assignment scheme for the CDMA(Code Division Multiple Access) cellular system using power allocation concept. Also, the performance of the proposed scheme was analyzed and it was compared with the channel assignment scheme using the fixed power allocation method in the CDMA cellular system. The proposed scheme allocates the power adaptively in according to the traffic loads and the traffic distribution pattern of neighbor cells in the forward link. We found that total call blocking probability (Pr) is more dependent on blocking probability($P_B$) than outage probability (Po) under physical number of channels ($C_{th}$)=30. Pr(Call Blocking Probability) is dependent on $P_B$(Blocking Probability) and Po(Outage Probability) at the same ratio under $C_{th}$=32, in which case P$P_{TA}$(blocking probability for the adaptive power allocation) is greater than $P_{TF}$(blocking probability for the fixed power allocation) about 6%.

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Performance of call handling schemes for radio mobile exchange communication system applied by timeout Queue (무선 이동통신 교환시스템에서 타임아웃(timeout)큐를 적용한 호 처리 방식의 성능해석에 관한 연구)

  • 우상철;윤종호
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.2 no.1
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    • pp.59-70
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    • 1998
  • In the wireless mobile exchange communication system, the proper handling of originating call(OC) and handover call(HC) is important. Specially, when it's viewed from the user side, mobile users feel more weighting soul disappointment with the handover blocking probability moving from current cell to adacent cell than with originating call blocking probability happening new call in current cell. Accordingly,this paper is proposed and analyzed the timeout buffer system and guard channel for decreasing handover blocking probability. In analytic result, The more guard channel increase,t he more originating call blocking probability increase and handover blocking probability decrease. Also, the more timeout duration increase, the more handover blocking probability decrease.

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Performance and blocking probability in a two-class CDMA system with mobile station of 2 classes (2 클래스 CDMA 시스템의 성능과 블록킹 확률)

  • 김두용;최덕규
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.6
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    • pp.1501-1509
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    • 1996
  • Mobile stations can be classified by the transmission power level in CDMA system. Different performance parameters will be given to each class of mobile stations so that the appropriate quality ofservices can be provided. In this paper, it is assumed that there are two clsses of mobile stations. with the classification of mobile stations, analytical models are presented for the estimates of the reverse link capacity and the blocking probability. From the model for the reverse link capacity, the maximum number of each class of mobile stations to be served is derived. It is shown that $E_{b/}$I reduction of 1 dB allows the capacity to be increased by 25% and the data transmission rate and the power control accuracy have a significant effect on the reverse link capacity and the blocking probability. Simulation results are provided for validating the anlaytical estimates of the blocking probability.ocking probability.y.

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The Relation of CLR and Blocking Probability for CBR Traffic in the Wireless ATM Access Network

  • Lee, Ha-Cheol;Lee, Byung-Seub
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.11C
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    • pp.1158-1163
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    • 2002
  • In this paper it is focused on the relation between CLR (Cell Loss Ratio) and blocking probability, GoS(Grade of Services) parameters in the wireless ATM (Asynchronous Transfer Mode) access network which consists of access node and wireless channel. Traffic model of wireless ATM access network is based on the cell scale, burst scale and call connection level. The CLR equation due to buffer overflow for wireless access node is derived for CBR (Constant Bit Rate) traffic. The CLR equation due to random bit errors and burst errors for wireless channel is derived. Using the CLR equation for both access node and wireless channel, the CLR equation of wireless ATM access network is derived. The relation between access network CLR and blocking probability is analyzed for CBR traffic.

Computation of Blocking Probability in a Loss System

  • Na, Seong-Ryong
    • Proceedings of the Korean Statistical Society Conference
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    • 2005.05a
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    • pp.203-207
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    • 2005
  • A loss system where two types of customers arrive in accordance with two independent Poisson processes is considered. An efficient recursive formula is developed for calculating the loss probability when the number of servers is large. Some practical examples regarding the performance evaluation of telecommunications networks are discussed.

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Admission Control Policy Heuristic Algorithm for fairness of Call Blocking Probability in Differentiated Service Networks (차별화된 서비스를 갖는 인터넷 망에서 호 블로킹 확률의 공평성을 위한 수락 제어 정책 Heuristic 알고리즘 연구)

  • Min, Jun-Ki;Rhea, Woo-Seop;Chung, Jong-Soo
    • Journal of Internet Computing and Services
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    • v.6 no.3
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    • pp.121-128
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    • 2005
  • Recently, as the research of effective resource management for supporting of various next generation internet service, the admission control mechanisms using the dynamic provisioning methods in differentiated service networks are studied. However, even though admission control mechanism is applied to the network, there exits the unfairness of call blocking probability among the different bandwidth requested services. In this paper, we propose the new admission control policy heuristic algorithm that provides fairness of call blocking probability between the large bandwidth requested service and the small bandwidth requested service. The simulation results show that the proposed algorithm provides not only blocking probability fairness but also high bandwidth utilization.

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Blocking Probability in an M/D/1/K Queue (M/D/1/K 대기행렬에서의 차단확률)

  • Seo, Dong-Won
    • Journal of the Korea Society for Simulation
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    • v.17 no.4
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    • pp.241-247
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    • 2008
  • In this study we consider an M/D/1 queue with a finite buffer. Due to the finiteness of the buffer capacity arriving customers can not join the system and turn away without service when the buffer is full. Even though a computational method for blocking probabilities in an M/D/1/K queue is already known, it is very complex to use. The aim of this study is to propose a new way to compute blocking probability by using (max,+)-algebra. Our approach provide a totally different and easier way to compute blocking probabilities and it is, moreover, immediately applicable to more generous queueing systems.

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The Performance Analysis of a DS/CDMA Cellular System using an Adaptive Array Antenna in Shadowing (전파음영 환경에서 적응 어레이 안테나를 적용한 DS/CDMA 셀룰라 시스템의 성능 분석)

  • Kim, Hyoung-Chae;Kim, Hang-Rae;Kim, Nam
    • Proceedings of the IEEK Conference
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    • 2000.11a
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    • pp.149-152
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    • 2000
  • In this paper, the reverse link performance of an imperfect power controlled DS/CDMA cellular system that uses a base station array antenna which can effectively remove the multiple access interference is analyzed considering both beam forming algorithm and power control error in shadowing. The blocking probability of the DS/CDMA cellular system based on array parameters, Eb/No and statistics of interference is derived, and then the system capacity corresponding to a certain blocking probability is calculated. On the assumption that the blocking probability is set 1 %, the system capacity using MCGM algorithm with 12 antenna arrays is increased about 59 % than that using 8 antenna arrays when power control error is 2.5 ㏈.

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The analysis and modeling of the performance improvement method of multistage interconnection networks (다단상호연결네트웍의 성능 향상 기법의 해석적 모델링 및 분석 평가)

  • 문영성
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.23 no.6
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    • pp.1490-1495
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    • 1998
  • Call packing has been recognized as a routing scheme that significantly reduces the blocking probability of connection requests in a circuit-switched Clos multistage interconnection network. In this paper, for the first time, a general analytical model for the point-to-point blocking probability of the call-packing scheme applied to Clos networks is developed. By introducing a new parameter called the degree of call packing, the model can correctly estimate the blocking probability of both call-packing and random routing schemes. The model is verified by computer simulation for various size networks and traffic conditions.

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