Universal Mobile Telecommunication System (UMTS) featured with high data rate is expected to provide real-time multimedia services over wireless cellular networks. To support the corresponding quality of service (QoS) for the multimedia services, 3GPP defined a Multimedia Broadcast/Multicast Service (MBMS) architecture that allows the delivery of multimedia streams from a NodeB to a group of service subscribers. With the variety of subscribers, the different device capability and user preference would cause a challenging problem for resource allocation. In this paper, to address this challenge, we propose WLAN Cooperative Channel Allocation (WCCA), a novel channel allocation scheme, which incorporates the layer-encoded technique and the WLAN-cooperative approach with the MBMS channel allocation. Taking advantage of layer-encoded streaming, the multimedia streams are split into multiple layer streams. The more layer streams the subscriber receives, the higher QoS for the subscriber. To meet the QoS requirements of the multimedia subscribers, we present a cooperative approach to deliver the layer streams more efficiently. In our approach, by appropriately exploiting the resources of WLAN to relay the layer streams from the quality-satisfied subscribers to the quality-hungry subscribers, the overall quality of multimedia services in UMTS networks can be significantly improved. The performance of WCCA is evaluated. The results demonstrate that WCCA outperforms the existing schemes in terms of both the subscriber satisfaction and the channel utilization.

通用移動通訊系統是一個被廣泛使用的第三代行動網路技術，該系統擁有高速傳送資料率的優勢，於無線蜂巢式網路中提供即時的多媒體服務。為了達到對應的多媒體服務品質，第三代合作夥伴計劃提出多媒體廣播與群播服務之網路架構，藉由共享的頻寬資源，將多媒體串流同時一併送至多位使用者。另一方面，使用者所持的裝置硬體能力有所不同，因此如何分配這些網路資源是當中的一項挑戰。為因應此項議題，本研究提出了新的通道資源配置方法，稱為「無線區域網路合作式通道配置機制」。這項機制結合分層式影像編碼技術與合作式無線區域網路，實現於多媒體廣播與群播服務通道配置上。利用分層式編碼串流技術，多媒體串流可被分割為多層型態，使用者接收到的層數越多，其服務品質也隨之越高；並適當利用無線區域網路資源，讓服務品質被滿足的使用者，可以轉送分層串流給需要的使用者，系統整體的多媒體服務品質能達到更多的提升。採用無線區域網路合作式通道配置機制的實驗結果顯示，該使用者的滿意量度、通道資源的使用，相較於以往提出的通道配置方法顯得更有效率。在實際設備方面，本研究實作出利用無線區域網路資源轉送分層串流，證明無線區域網路合作式通道配置機制的通道配置方法在實際架設上是可行的。

[1] 3GPP. 3rd Generation Partnership Project; Technical Specification Group. Multimedia
Broadcast/Multicast Service (MBMS); Stage 1. Technical Specification 3G TS
22.146 ver. 8.2.0. March 2007.
[2] Information technology - Coding of audio-visual objects. Part 10: Advanced Video
Coding. ISO/IEC 14496-10. 2005.
[3] 3GPP. 3rd Generation Partnership Project; Technical Specification Group. Comparison
of DSCH and FACH for MBMS. Technical Specification 3G TSG RAN WG#29,
R1-02-1325. November 2002.
[4] 3GPP. 3rd Generation Partnership Project; Technical Specification Group. Considerations
on power allocation for MBMS. Technical Specification 3G TSG RAN
WG#29, R2-02-1669. November 2002.
[5] 3GPP. 3rd Generation Partnership Project; Technical Specification Group. MBMS
Power Usage. Technical Specification 3G TSG RAN WG#31, R2-02-2110. November
2002.
[6] A.-C. Pang, S.-R. Yang, and C.-K. Yang. Layer-Encoded MBMS Channel Allocation
for Mobile Networks. IEEE LCN 2007, pages 15–18, October 2007.
[7] Y.-B. Lin. Performance Modeling for Mobile Telephone Networks. IEEE Network,
11(6):63–68, November 1997.
[8] S.-J. Lin. Channel Statistics for AMC Mode Operation in Mobile WiMAX. April
2008.
[9] I. Stepanov, Stuttgart University. CanuMobiSim - a framework for user mobility
modeling. 2005.
[10] D.B. Johnson, and D.A. Maltz. Dynamic Source Routing in Ad Hoc Wireless Networks.
pages 153–181, 1996.
[11] The WinPcap Team. The WinPcap manual and tutorial for WinPcap 4.1.2, 2009.