行動數據通訊之發展趨勢研究

Abstract

行動數據通訊服務讓使用者可以在行動中傳遞資訊，因此可以提高生產力及工作效率。可以提供行動數據通訊服務的網路包括：1.專屬行動數據網路2.蜂巢式數據網路3.行動無線電數據網路4.PCS數據網路5.行動衛星通訊網路6.雙向傳呼網路。目前行動數據通訊在發展上遭遇到的瓶頸有：傳輸速度低、系統與技術無統一標準、使用者成本過高、以及無法和語音系統整合等困難。 在眾多的行動數據通訊網路中，蜂巢式數位分封數據網路(CDPD)提供TCP/IP通訊規約且有可共用AMPS頻道與基地台設備等優點，因此為目前最廣泛使用的行動數據網路。GSM提供行動數據的升級方案如HSCSD、GPRS、及EDGE等無線電傳輸技術，能夠提供涵蓋範圍更廣、傳輸速率更快、更具有使用彈性的行動數據通訊服務。 行動數據通訊服務的應用領域由最初的垂直專業市場逐漸朝向水平大眾市場拓展，無線網際網路接取便是水平市場中最有潛力的應用。為了解決無線網際網路受限於行動終端設備無法顯示Internet多媒體資訊的困難，以及行動數據網路速度慢、無統一標準等問題，因此制訂全球一致的WAP標準，讓業者能迅速地開發各種軟、硬體，從而降低使用者的使用成本，開拓無線網際網路市場。 第三代行動通訊的傳輸技術已確定使用W-CDMA標準，在IMT-2000中，高速行動中數據的傳輸速率可達384Kbps，足夠提供行動多媒體資訊服務。 本研究針對行動數據通訊的市場現況與未來發展趨勢，提出以下四點建議： 1. 專屬行動數據服務業者應致力於垂直應用市場的開發，使企業用戶了解採用行動數據的效益，提供符合各 別需要的專屬應用服務。 2. 行動電話業者應擴充網路容量與速度，提供大眾水平市場高速的行動數據服務，同時努力開發無線網際網 路的普及應用。 3. 行動終端製造廠商應生產低價位、低耗電性、具有寬大顯示幕及多種輸入方式、兼具語音及數據功能的終 端產品，以符合無線網際網路對於多媒體資訊輸出入的要求。 4. 政府為有效運用無線電頻譜，應解除獲得執照業者提供任何種類行動通訊服務的限制，以促進市場的蓬勃 發展和公平競爭。

Mobile data communication allows people to exchange data while in motion. It can increase efficiency and productivity. The following network systems can provide different levels of mobile data services: 1. Dedicated mobile data networks, 2. Cellular mobile telephone networks, 3. Special mobile radio networks, 4. PCS networks, 5. Mobile Satellite Service networks, and 6. Two-way Paging networks. The common criticisms of existing mobile data communications systems include: slow transmission speed (<19.2Kbps), lack of international standards, terminal equipment costs and usage charges too high, and in capable of integrating with voice communications. There are two most popular cellular telephone systems in the world, namely the AMPS and the GSM systems. The CDPD mobile data network uses existing AMPS network and supports TCP/IP protocol, therefore it is the most widely deployed mobile data network in the world. The GSM cellular telephone network is evolving to provide mobile data services either via circuit switching technology, HSCSD, or via packet switching technology, GPRS and EDGE. It is going to make serious impact in the mobile data communications market. The 3rd generation mobile telephone system, IMT2000, has adopted the W-CDMA technology standard. The transmission speed can support as high as 384 Kbps in high speed motion. Not only data but also video could be integrated with voice in future mobile communication services. This research led to the following four recommendations: 1. The existing mobile data service providers should put in efforts to develop special business applications in the vertical market. 2. All mobile communications service providers should upgrade network capacity and transmission speed to prepare for wide proliferation of wireless internet applications. 3. The manufacturers should develop end user device with lower power consumption, larger display, voice recognition input and low cost. 4. The mobile telephone service providers could start invading the mobile data services market. While the mobile data service providers have already been also eroding the paging market. In order for the radio spectrum to be used most efficiently and economically, the government should allow the mobile service providers to use their assigned radio spectrum to offer whatever service they deem profitable.