在無線通訊網路迅速蓬勃發展的今日，UMTS系統在即將到來的3G 無線網路上扮演一個重要的角色。

在UMTS 無線端上傳送正確無誤的資料，需藉由 RLC 協定來達成，RLC 協定是一個高度能適應環境且能藉由調整參數來達到 QoS 的要求，因此，最佳化 RLC 協定的參數以達到最佳效能是一件重要的課題。

本論文會探討分析 POLL TIMER 和 MAXDAT 這些參數值，以期許能對最佳化3G UMTS 系統有一點貢獻。

With the rapid advances in wireless communications, Universal Mobile Telecommunications Systems (UMTS), playing a main role in the emerging third generation (3G) wireless networks.

Reliable data transfers on the UMTS radio interface are provided by the RLC protocol. The RLC protocol is highly adaptable and specific primitives allow the tuning of the protocol for different QoS requirements. Therefore, it is critical to optimize the RLC protocol to achieve the best performance.

The performance trends against the poll timer and MAXDATA settings are analysed and summarized, respectively, for use in the design of optimized 3G UMTS systems for data services.

【 1 】H.Kaaranen , A.Ahtiainen , L.Laitinen , S.Naghian and V.Niemi , UMTS Networks Architecture , Mobility and Services , JOHN WILEY & SONS , West Sussex , England , 2001 .

【 2 】 3GPP organization, http://www.3gpp.org.

【 3 】3GPP Technical Specification 25.331 V3.0.0, Radio Resource Control (RRC); Protocol specification, 3GPP, 1999.

【 4 】3GPP Technical Specification 25.211 V6.3.0, Physical channels and mapping of transport channels onto physical channels (FDD), 3GPP, 2004

【 5 】H. Holma and A. Toskala, WCDMA for UMTS: radio access for third generation mobile communications, John Wiley & Sons, Chichester, West Sussex, England; Hoboken, N.J., 2002.

【 6 】3GPP Technical Specification 25.322 V6.3.0, Radio Link Control (RLC) protocol specification, 3GPP, 2005

【 7 】The Network Simulator - ns2, available at http://www.isi.edu/nsnam/ns/.

【 8 】A. Jehangir, A. Lo, D. Baakman, N. Whillans, I. d. Bruin, F. Brouwer and S. Oosthoek, Enhanced UMTS Radio Access Network Extensions (EURANE) for ns-2, available at http://www.ti-wmc.nl/eurane/, 2006.

【 9 】Qinqing Zhang and Hsuan-Jung Su. Performance of UMTS radio

link control. In Proceedings of IEEE International conference on

Communications, volume 5, pages 3346–3350, 2002.

【 10 】A. S. Tanenbaum, Computer Networks, Fourth Edition, Prentice Hall, 2003.

【 11 】 3GPP Technical Specification 25.321 V3.0.0, Medium Access Control (MAC) protocol specification, 3GPP, 1999.