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Load-Aware Cell Selection Method for Efficient Use of Network Resources

효율적 망 자원 이용을 위한 부하 인지 셀 선택 기법

  • Park, Jaesung (The Univ. of Suwon Department of Information Security)
  • Received : 2015.09.01
  • Accepted : 2015.10.30
  • Published : 2015.12.30

Abstract

Downlink (DL) data rate for a MS is influenced by not only the signal to interference and noise ratio (SINR) but also the amount of radio resources allocated to the MS. Therefore, when a MS uses SINR to select a cell to associate with, it cannot receive the fastest DL data rate all the time if it associates with a congested cell. Moreover, the SINR-based cell selection may result in cell loads unbalance, which decreases the efficiency of a network. To address the issue, we propose a novel cell selection method by considering not only SINR but also a cell load which are combined into two cell selection criteria. One is the maximum achievable data rate and the other is the minimum outage probability. The simulation results show that the cell selection based on the maximum achievable data rate is superior to the SINR-based method and the method using the minimum outage probability in terms of the system efficiency and the fairness in cell loads while the cell selection method based on the minimum outage probability is superior to the others in terms of the outage probability of a MS.

단말이 망에서 제공받는 데이터 전송율은 단말과 셀 사이의 SINR 뿐만 아니라 셀이 단말에게 할당하는 무선 자원양에 의해서도 결정된다. 따라서 단말이 SINR만을 기준으로 접속할 셀을 선택하면 비록 최대 SINR을 제공하는 셀에 접속한다고 하더라도 최대 서비스율을 제공받지 못할 수도 있다. 또한 네트워크의 입장에서는 SINR을 기준으로 접속 셀이 선택되므로 일부 셀들은 다수의 단말이 접속하는 반면 주변의 다른 셀들은 접속 단말의 수가 적게 되어 셀간 부하 불균형 상태가 발생될 확률이 커지고 이로 인해 이동 통신 시스템의 자원 이용율이 낮아지게 된다. 이에따라 본 논문에서는 SINR뿐만 아니라 셀의 부하를 고려한 접속 셀 선택 방법을 제안한다. 이를 위해 접속 셀 선택 지표로 SINR 대신에 최대 데이터 전송율과 최소 전송율 단절 확률을 제시한다. 제안 기법의 성능 평가를 위한 모의실험 결과 최대 데이터 전송율을 이용한 셀 선택 방법은 타 기법에 비해 시스템 효율과 셀간 부하 균등 측면에서 향상된 성능을 보였으며 최소 전송율 단절 확률을 이용한 셀 선택 방법은 타 기법에 비해 단말의 평균 전송율 단절 확률 측면에서 향상된 성능을 보였다.

Keywords

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