應急蜂巢式行動網路的建構排程

Scheduling of Contingency Cellular Network Deployment



王彥嵩

大型自然災害會癱瘓通訊系統嚴重影響到救災效率,本論文旨在快速提出一個建構排程供應急通訊系統佈建。無線通訊系統的成熟極大的為使用者帶來便利性,但當發生大規模的地震或強烈颱風等重大天然災害發生時通訊系統卻常常因架構原因隨著電力與交通系統的損毀而癱瘓。由歷年大型災變中多數災區內之行動通訊系統全面中斷即可印證行動通訊系統其實是極為脆弱,而有效運作的通訊系統卻是災情傳遞、資源調度以及互助協調是否順利的關鍵因素。 本篇論文所探討的應急通訊系統是利用倖存的連通基地台和斷訊卻沒有損毀的基地台建構一個臨時性的網路,稱為應急蜂巢式行動網路(contingency cellular network,CCN)。由於災區的交通系統可能癱瘓,因此CCN的建構需視各種運輸能力而規劃,而各個地方受災情況不盡相同,CCN的建構順序也須辨明輕重緩急依序建構,網路拓樸的規劃是本研究團隊的另一研究主題,本文主在探討如何在網路拓樸已知情況下進行CCN構排程以達到最大的救災效益,因此我們提出一適合CCN樹狀結構的最佳化排程模型,以追求救災效益的最大化,這些模型可供使用者(救災指揮單位)系統化的解決CCN建構排程問題。 模型包含CCN樹狀拓樸、基地台數目、基地台建構時間、基地台重要度、拓樸連線集合和建構工作組數。在此模型下提出一個考慮各基地台的時效性以及重要性而進行快速排程的演算法,此演算法透過計算排程總救災效益決定優劣。分三階段實驗。三階段實驗皆可在數秒內得出接近最佳解的排程。

When stricken by a large-scale disaster, the efficiency of disaster response operation is very critical to life saving. We propose to build a contingency cellular network to support emergency communication in large scale natural disasters by connecting disconnected base stations. This paper addresses the deployment scheduling problem. The advance of mobile communication technologies has brought great convenience to users. Cellular phone becomes the first communication tool most people would use in emergency. However, cellular networks were usually crashed due to earthquake, typhoons or other natural disasters due to power outage or backhaul broken. Unfortunately, the efficiency of communication system is a critical factor to the success of disaster response operation such as resource allocation as well as coordination of rescue and relief operations. We designed a contingency cellular network (CCN) by connecting physically intact but service-disrupted base stations together with wireless links. As the disaster area's transport system may be paralyzed, the construction of CCN may have to reply on air transportation such as helicopter or even airdrop. Since the transportation capacity may be very limited, scheduling of CCN deployment order according to the demand of disaster operation becomes an important issue. We model the CCN Deployment Scheduling Problem into a combinatorics optimization problem aiming to maximize disaster operation efficiency. The problem is proven NP complete. Thus, we design an efficient heuristic algorithm to solve the problem when it is needed in urgent.