隨著通訊技術、無線網路的快速發展，人類溝通的方式與以往大相逕庭，不再受到傳統有限媒介與地理環境的限制，大大地放寬了通訊的範圍與應用。而在無線通訊的基礎上，智慧型行動裝置得以普及，並造成各式各樣不同類型的服務不斷推出，提供人類生活便利的廣度。其中，訴求多人共同實現的群組式服務，更是一項具有願景及相當應用價值的議題。
在本論文中，我們將探討在基地台網路環境中，動態群組形成問題。在我們的研究中，形成群組需要在截止時間時，在目的地聚集足夠的有興趣的參加者，但由於系統無法預先知道節點之興趣，因此，如何通知節點關於群組的消息以及維護一定人數則成為研究的重點。另外，由於我們的環境架設在基地台網路環境中，並不存在一個中央控制管理組織能夠隨時的得知每個節點的動向，故在此研究中，將採用分散式的方法通知節點與維護群組的大小。
除此之外，為了評斷我們方法的好壞， 我們定義一組目標函數，此目標函數主要與參加人數有高度相關，當參加者人數不足下限或者超過上限時，需付出較多成本，當收益減去成本的盈餘越大時，則代表該方法的成團效果越好。最後，我們另外提出兩種群組形成方法與我們的方法比較，並且在不同設定之下討論其優缺點。

The rapid advancement of wireless communication technology has dramatically changed the way human beings communicate. People are now able to overcome the constraints of physical wired connection to extend their reach via wireless networks anytime and anywhere. On the basis of this foundation, mobile computing devices prevail in our daily life, and offer a variety of applications that are widely useful for the users. Among these applications, grouping services occupy a peculiar domain, which calls for a group of users to accomplish a particular task. The prospects of such services are expected to be brightening in the near future.
In this thesis, we study the dynamic grouping formation problem in Cell-based network. In our research, a group is formed if there are enough participants at determined time and location. It is important to propose a notification scheme to inform the participants without knowing any prior knowledge of the participants. Since there is no centralized server that could monitor the users in our environment, it is more feasible to propose a distributed notification scheme.
Besides, a general form of objective function is also provided in this work to measure how well the group formation is. The objective function is related to the amount of registered participants. A penalty score is also defined in this function to handle fail formation and extra participants.
In addition, we also propose two extra notification schemes. We compare all these notification schemes under different environments and discuss their pros and cons.

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