在DVB-H與WiMAX匯流網路上的串流傳送技術探討

Streaming Service Delivery over DVB-H and WiMAX Converged Networks

焦信達(Hsin-Ta Chiao) ； 江志偉(Jhih-Wei Jiang)

《電腦與通訊》 136期 (2010/12) Pp. 53-60

https://doi.org/10.29917/CCLTJ.201012.0009

摘要

在行動網路與廣播網路所構成之匯流網路上，進行異質網路串流服務傳送之技術，可使營運商以更有效率及更有彈性的方式，傳送多媒體內容至用戶端。因此，與異質網路串流服務傳送相關的功能，近來已在DVB-H上的IP服務層標準中被標準化了，例如：DVB-IPDC標準與OMA BCAST標準。在前述的兩個標準中，無縫串流服務切換(Seamless Streaming Service Switching)是欲達到前述異質串流服務傳送所需的一項關鍵技術。在本論文中，我們首先將以前述的兩個標準為基礎，說明在DVB-H廣播網路及WiMAX行動網路上，實作無縫串流服務切換時所需的技術方法與細節。在我們的實作方式中，避免了在進行服務切換時，同時執行兩組影音解碼器的狀況，以減少對終端裝置硬體的需求。此外，我們也進行了串流切換的效能實驗分析，實驗數據是在DVB-H廣播網路信號強度變化快速的假設下進行量測的，用以模擬終端裝置在進入或離開房間或建築物時的極端狀況下，DVB-H信號的變化情形。最後，我們也討論了與無縫串流服務切換相關的其他研究議題，例如：串流服務切換的乒乓效應，並提出可能的解決方法。

關鍵字

行動多媒體廣播 ； 廣播與行動匯流 ； 混合式服務傳送

並列摘要

Hybrid streaming delivery over converged mobile and broadcast networks can enable operators to transmit multimedia contents to terminal devices in a more efficient and flexible way. Consequently, the functions related to hybrid streaming delivery are recently standardized in the IP-based service layer standards for DVB-H, i.e. DVB-IPDC and OMA BCAST standards. In both standards, seamless service switching is one of the key building blocks for achieving hybrid streaming delivery. In this paper, we first describe the experiences for implementing the function of streaming service switching between DVB-H broadcast and WiMAX mobile networks according to the abovementioned standards. In our implementation, instantiating two sets of audio and video codecs in parallel during service switching is avoid for reducing the required hardware resources in a terminal. In addition, the experiment results of streaming service switching are provided to show the performance of our implementation in an extreme test environment where the level of a DVB-H signal could be varied rapidly for simulating the observed room or building penetration loss for a moving terminal. Finally, the research issues related to seamless streaming service switching such as the ping-pong effects of service switching are discussed, and the possible solutions are also proposed.

並列關鍵字

Mobile Multimedia Broadcasting ； Broadcast and Mobile Convergence ； Hybrid Service Delivery