在通用行動電話系統下支援動態服務之高效率代理人平台

Abstract

在虛擬家庭環境中最重要的關鍵概念是動態服務之提供。動態服務之提供允許使用者在不同的網路環境中使用不同樣式的裝備來動態地存取各種不同的服務。在第三代通訊系統及之後的電話網路將都會有這樣的功能。因此使用者可以在任何時間動態地訂閱新的服務。而系統業者和服務提供者也可以立即動態地來提供該項服務給新訂閱的使用者。而在第三代行動通訊夥伴合作計畫（3GPP）的通用行動電話系統(UMTS)也考慮到這個目標，因而提出行動網路增強邏輯之訂製應用（CAMEL）架構。依據此架構，我們提出了一個有效率的行動代理人平台來提供動態服務，而這個平台可以大量地減少訊息的流量。為了評估這個平台，我們使用來話與發話的例子來說明行動代理人的運作。另外我們建構一個機率模式來計算訊息流量與服務下載的期望值，藉此來分析平台效能。而這個結果可以幫助系統業者來了解不同因素對網路效能的影響。在現存的方案中，在通用行動電話系統之分散處理環境是採用基於一般物件要求代理架構（CORBA）的行動代理人平台。而這個平台需要一個標準以便在不同廠商所開發的行動代理人環境下互容與整合。因此，物件管理聯盟（OMG）已制訂移動代理人系統互容機制（MASIF）來做互容與整合的工作。然而這個方案仍存在一些安全與效能的問題。效能分析顯示，我們所提出的行動網路增強邏輯之訂製應用行動代理人平台可以比基於一般物件要求代理架構（CORBA）之平台減少40％的訊息流量。因此我們所提出的平台不但可以提供有效率的效能和行動管理，也可以加強平台的安全性和互容性。

An important key concept of the Virtual Home Environment (VHE) is dynamic service provisioning. Dynamic service provisioning allows users to access all kinds of services dynamically from different types of devices in different networks. In 3G and B3G, the telecommunication network will have such a capability. The users can dynamically subscribe new services anytime, and the system operator or service provider can dynamically provide services to subscribed users immediately. The goal was considered by the Universal Telecommunication Mobile System (UMTS) in 3GPP, and the Customized Applications for Mobile Enhanced Logic (CAMEL) architecture was then proposed in UMTS. Based on the UMTS CAMEL architecture, we propose an efficient mobile agent–based platform to provide services dynamically, which can greatly reduce the signaling traffic. To demonstrate the efficiency of our agent-based platform, we use the operations of incoming and outgoing calls to illustrate the operation of mobile agents. We also constructed a probabilistic model to analyze the performance of expected traffic volumes that include signaling and service downloading traffic. The results can help system operators to understand the impact of different factors on network performance. In an existing approach, a CORBA agent-based mobile agent platform was deployed on a distributed processing environment in UMTS, and they required a standard, OMG Mobile Agent System Interoperability Facility (MASIF), to be interoperable between agent environments of different vendors or operators. However, there are some problems in this approach, such as problems in the aspects of security and performance. Analysis shows that the signaling traffic in our UMTS CAMEL agent-based platform can be reduced 40% in outgoing call scenarios compared to that in the CORBA agent-based agent platform. Our platform can provide efficient mobility management, and enhance network performance, security and interoperability.