A Study of Survivability Enhancement in Personal Communication Network using Partition by Interleaving Access Links

[[abstract]]中文摘要 個人行動通訊的角色在現今高度商業化的社會已不可或缺，因此如何提高或強化 通訊網路存活度的研究已經是個重要的課題。有釵h文獻提出如何提高或強化網路存活 度的策略，但是我們發現目前的方法仍有不足及可改善的空間。尤其在鏈路(專線)的設 計上因目前的固網公司在建設其有線接取網路時，普遍的設計都是以一個機房為中心來 服務該機房鄰近的區域，此機房為該區域用戶線路的終端及電路交換的中心，我們稱之 為局端，整個城市可能由數個或數十個局端來提供通信的服務，此種依鄰近地區來劃分 的有線接取網路設計法我們稱之為地區劃分法。 由於依地區劃分法設計的網路容易因該局端的纜線或設備發生障礙時而影響該局 端所服務區域的所有鏈路，因此本論文針對個人行動通訊網路的鏈路設計提出間插式接 取鏈路劃分法，此設計法是以個人行動通訊網路基地台與基地台控制中心間鏈路之劃分 設計，並結合射頻訊號涵貌滲S性來提高網路存活度。 間插式接取鏈路劃分法的設計是選擇鄰近的P 個基地台組成一個群集，該P 個基 地台的專線分別向P 家不同的固網公司租用，因此當一個局端發生障礙時只會影響該群 集內的一個基地台，同時利用無線訊號的涵趙S性讓鄰近的基地台來服務受影響基地台 的涵趕洁A以降低障礙對個人行動通訊網路的衝擊。本文中也將討論在實際網路中不規 則的基地台配置如何作鏈路群組的劃分，來達到間插式接取網路的設計目的。 我們依據不規則基地台配置的劃分準則，將範例區域做基地台群組的劃分，根據 我們的模擬結果顯示，即使在間插式劃分群組P=2 的設計下，當其中一個局端發生障礙 時整個區域的室內涵輔v平均可以比地區劃分法提高7.8%，在特定區域甚至可提高 93.2%(中山特定區域)，C/I≥ 12dB 涵貌漯穛{在整個區域平均可提高10.7%，在特定區 域可以提高達81%(中山特定區域)。[[abstract]]ABSTRACT The role of PCS (Personal Communication System, PCS) has become indispensable in a high-business developed society. So the research of how to enhance the survivability robustness of the PCS network has become a major issue. There were many strategies in papers had been discussed to enhance the survivability of the PCS network. However, we found there is much room for improvement. Especially in the design of transmission links (or lease lines), normally the fixed line operators design their networks using one office as their central point and extend the networks to the neighboring area. This local loop of the customer was terminated in this office and make links exchange in the office. This office was named “Central Office”. It may have dozens Central Office to offer the communication services for whole city. This designing methodology is dependent on the partition of neighboring area called “Local Partition”. The communication links may be completely impacted when cable or transmission equipments fault occurred in Central Office if the networks were designed in Local Partition. Therefore, we recommend a strategy called “Partition by interleaving access links”, which is applied to enhance the survivability of PCS network with the design of BTS-BSC links in iii interleaving arrangement. Besides, with combining the characteristic of the coverage of RF signal, this strategy becomes more feasible to enhance the robustness of the network survivability. The designing method of “ Partition by Interleaving Access Links “ is to select the number of neighboring BTS of “P” as a cluster. Different fixed line operators will serve each BTS-BSC links within the cluster. So there is only one BTS will be impacted within the cluster when one “Central Office” failed. And the radio signal of neighboring non-impacted BTS could have possibility to cover the area of impacted BTS. This may reduce the service impact to PCS network. Due to the irregular layout in BTS of PCS network, how to make partition of BTS in irregular network topology will be discussed in this paper. For irregular layout of BTS, we have made group partition according to our partition guideline. According to the result of simulation, even in the design of partition P=2, when transmission network fault happened in central office, indoor coverage could have 7.8% improvement in whole area and 93.2% improvement in particular area which compared to local partition. In performance of C/I≥ 12dB, the improvement are 10.7% in whole area and 81% in particular area