WB-CDMA/WLL系統之MAC層通信協定研究

Abstract

國際電信組織(ITU)約於十年前就開始起草第三代無線行動通信標準(IMT-2000)的制訂，其目標是訂定一種全球通用的無線行動通信標準。目前國際電信組織總共收到十五份提案，比較主要的兩個分別為：由歐洲與日本所支持的UMTS、及美國所支持的cdma2000。由於UMTS對世界上佔有率最高的GSM系統提供向下相容、而且世界上大部份國家都傾向基地台不同步的作法，因此由3GPP所主導制訂的UMTS成為最有希望的提案。 針對第一代及第二代無線行動通信的缺點，IMT-2000所提出的主要目標有：較高的頻譜效益及系統涵蓋、具備全球漫遊功能、支援多媒體服務、提供服務品質保證(QoS)。為了達到其最後兩項功能，我們需要設計功能完善的MAC層對整個系統資源做妥當的分配及管理。 本論文即根據3GPP所制訂的UMTS，對MAC層通信協定進行研究。我們希望可以根據既有規範的UMTS規格書做基礎，對MAC層的演算法及狀態機做研究，設計出能提供多媒體與服務品質保證的WB-CDMA/WLL系統之MAC層通信協定。

The ITU started to draft the standard of third generation mobile communication about ten years ago, and they aimed at defining a "global" standard for mobile communication. Now the ITU has received fifteen proposals, and the main two of them are UMTS (sponsored by Europe and Japan) and cdma2000 (sponsored by US). UMTS is compatible with GSM, which is the most popular mobile communication system in the world, and most countries prefer that the timing between base stations is asynchronous. Due to the two factors above, the UMTS proposal defined by 3GPP becomes the most popular proposal. In order to improve the drawbacks of 1st and 2nd generation mobile communication systems, IMT-2000 aims to provide : better bandwidth efficiency and coverage 、 global roaming 、 multimedia 、 QoS (Quality of Service). For achieving the last two functions, we need to develop a sophisticated MAC protocol for well management of radio resource. This thesis is researching into the MAC protocol, based on UMTS standard of 3GPP. We try to study and develop the algorithm and state machines of MAC protocol, and design the MAC protocol of WB-CDMA/WLL for multimedia and QoS, bases the existing specifications of UMTS.