現今，人類社會正遭逢醫療人力短缺。此外，在醫療領域中的不同資料封包會有不同的服務品質需求，例如: 與體溫相關的資料封包可以週期性的傳送，然而心跳速率的封包必須即時的傳輸。由IEEE 802.15.6任務群組提出的無線人體區域網路不僅對於不同封包可以提供適當的服務品質，而且提供了高達每秒10個百萬位元的傳輸速率。在醫療領域上，無線人體區域網路不僅可以用在術後復原的即時監控，也可以用來遠程監控慢性疾病。如此一來，人們可以更有效率與及時接受治療。不同於大多數的研究，假設封包的抵達程序是飽和流量，也就是說系統處於一直有封包要進行傳輸的狀態，而我們考慮了非飽和的流量情境。明確地說，我們假設封包的抵達程序是波以松。除此之外，在實際的系統中，當系統正在傳輸封包時，需要有一個佇列容納新抵達的封包，否則如果抵達的當下佇列已經容納不下新的封包時，新的封包就會被阻塞。更重要的是，當系統的負載越來越重時，在佇列中的等候時間會比在媒體進接控制層中的服務時間長。在我們的研究中，我們考慮了由多於一個節點以星狀拓樸形成的無線人體區域網路，這個網路中的每一個節點都擁有各自的有限佇列以容納兩種不同的優先權封包直到他們被成功傳輸或丟棄。我們著重於如何改進高優先權封包的等候時間。我們採用非占先式優先權的排隊法則。此外，我們考量了兩種情境:對稱及非對稱封包大小。在對稱的情境下，每一種優先權的封包都有相同的封包大小，然而在非對稱的情境下，高優先權封包的封包大小是小於低優先權封包的封包大小。我們推導所考慮系統的解析模型，而相關的平衡方程式是藉由疊代演算法求解。我們研究了不同系統參數對於我們感興趣的效能指標的影響，這些系統參數包含了高優先權抵達速率、低優先權抵達速率、系統大小、酬載大小、超訊框大小。我們所感興趣的效能指標包含了阻塞機率、成功送達率、系統平均封包數、佇列平均封包數、系統平均等候時間、佇列平均等候時間。最後但並非最不重要的，我們利用電腦模擬來驗證解析模型的準確性。

Nowadays our society is suffering from serious lacking of medical personnel. Furthermore, in the medical field different data packets may have different QoS requirements, e.g., the body temperature packets may be transmitted at regular time intervals, whereas the heart beat packets need to be sent at once. The wireless body area network (WBAN) is proposed by IEEE 802.15.6 to provide not only appropriate QoS to different data packets, but also a data rate up to 10Mbps. With WBAN, we can enforce not only real-time monitoring of postoperative recovery, but also telemonitoring of chronic disease. In this way, people can receive treatment in time and more efficiently. Unlike most studies on WBAN assuming that the packet arrival process is saturated, i.e., there is always a packet ready for transmission, we consider the non-saturated traffic cases. Specifically, it is assumed that the packet arrival process is Poisson. Furthermore, in practical systems, a queue is needed to accommodate any newly arrived packet finding the system is busy transmitting a packet; otherwise the packet will be lost. More importantly, when the system load becomes more heavy, the waiting time in queue will be bigger than the service time in MAC layer. In our study, we consider a WBAN with more than one node in the star topology, where each node is equipped with a finite queue to accommodate packets of two priority types until they are transmitted or dropped. We focus on how to improve the waiting time of high-priority packets. The non-preemptive priority queueing discipline is adopted. We consider two scenarios: symmetric and non-symmetric. In the symmetric scenarios, the payload sizes of the packets of different priority types are the same, whereas in the non-symmetric scenarios the payload size of the high-priority packets is smaller than that of the low-priority packets. The analytical models of the considered systems are derived and the associated balance equations are solved with an iterative algorithm. We study the effect of various system parameters on the performance measures of interest, e.g., the high priority arrival rate, the low priority arrival rate, the system size, the payload size, and the superframe size. The performance measures of interest are blocking probability, throughput, average number of packets in system, average number of packets in queue, average waiting time in system and average waiting time in queue. Last but not least, the computer simulation is utilized to verify the accuracy of the analytical model.

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