行動寬頻網路之信令分析與資源排程研究

Signaling Analysis and Resource Scheduling in Mobile Broadband Network

林孟賢(Meng-Hsien Lin)

指導教授 ： 陳彥文

國立中央大學/資訊電機學院/通訊工程學系/博士(2015年)

摘要

近年來，隨著行動寬頻網路普及、社交服務及新興服務的蓬勃發展，使用智慧型行動裝置在任何地方上網使用相關服務已成為常態。然而，由於智慧型行動裝置的多變性與行動新興服務的多元化，不同裝置與服務對行動寬頻網路與服務品質有不同的要求，且行動寬頻網路的頻譜資源與相關設備處理能力有限，如何兼顧有效資源排程、降低智慧型行動裝置的電力消耗及增加使用者滿意度將變得更具挑戰性。
本論文首先探討既有的社交服務搭配智慧型行動裝置在3G網路上之信令議題，一般而言，手機製造商與社交服務會分別設計省電機制來增加裝置續航力，以及保持連線機制讓使用者有更佳的互動性。然而，上述機制將產生大量控制信令。為了瞭解實際狀況，我們在商用網路上量測社交服務搭配不同款的智慧型行動裝置所產生的信令與封包流量，經過分析後，我們發現不同的社交服務有不同的連線行為，以及不同的智慧型行動裝置也有不同的省電與信令行為，故在此研究中我們提出可能的解決方案，期望能降低信令風暴之議題，而透過收集到的信令行為，將有機會在控制平面(control plane)上建立社交網路服務模型。
接著，在長期演進技術(Long Term Evolution, LTE)的下行鏈路上(downlink)，我們考量服務品質(QoS)與用戶通道狀況，提出服務品質感知機制(QoS Aware Scheme, QAS) ，以及考量裝置之儲存緩衝與用戶通道狀況，提出儲存緩衝感知機制(Buffer Aware Scheme, BAS)資源排程，並以啟發式演算法找出資源方塊(Resource Block, RB)與裝置之最佳匹配後進行資源排程，服務品質感知機制(QAS)的模擬結果中發現在HTTP服務中省電效果有限，但在視訊服務中可達到比較好的省電的效果，且跟其他機制比較起來裝置的耗電較平均。在儲存緩衝感知機制(BAS)下透過限制可連線至基地台之裝置數量，藉此避免過多裝置競爭有限資源與降低行動裝置的耗電量，儲存緩衝感知機制(BAS)模擬結果發現在高畫質視訊服務與使用人數眾多的情況下，不僅可維持一定的網路吞吐量與省電程度外，還可有效降低傳送時間與信令數量之表現。

關鍵字

行動網路 ； 信令 ； 資源排程

並列摘要

In recent years, because of the increased prevalence of mobile broadband network and the rapid development of social network service (SNS) and emerging services, it attracts numerous users to access the services through various types of smart devices at any location. However, due to the diverse smart devices and emerging mobile services, different types of devices and services have different requirements of mobile broadband network and quality of service. Due to limitation of mobile broadband spectrum resources, network component capability, and battery lifetime, how to balance resource scheduling, power consumption, and user experience will become more challenging.
In this dissertation, we discuss signaling in 3G Environment for SNS first. To save power, a smart device was designed to release a data path immediately or to follow standards for transitioning to a power saving state. To provide better interaction, SNS was relevant power design Stay connected with the mechanism, the mechanism described above will produce a large number of signaling burden. To examine the signaling effects, this study analyzed measurements of signaling introduced by diverse smart devices when these devices run SNS in a real operator environment. The measurement results indicated that a high number of RRC related signaling messages are produced when a smart device runs a SNS, and the generated signaling messages introduce a heavy computational burden on the control plane. A possible enhancement approach is proposed and we expect the approach can reduce the signaling storm. The signaling fingerprints can be applied to establish signaling models for analyzing the performance of control planes.
In downlink long-term evolution, we propose quality of service (QoS) aware scheme (QAS) and buffer aware scheme (BAS) scheduling consider the QoS with user channel conditions and buffer of user equipment (UE) with the user channel status, respectively. And determines the scheduling priority based on a designed heuristic weighting function. In proposed QAS, the simulation results show the proposed scheme improves power consumption in the case of video-streaming service but not HTTP service. The simulation results show that the proposed scheme allocates resources more fairly than other schemes used for comparison. To avoid too many UEs contending the limited radio resources and reduce power consumption, the proposed BAS estimates the allowable maximum number of UE. The simulation results show the proposed BAS achieve achieves less streaming delivery time and generates less signaling overhead than the best CQI scheme when the traffic load is heavy and high resolution video streaming sources.

並列關鍵字

LTE ； Scheduling ； Signaling

參考文獻

[9] 3GPP TS 25.331 V12.0.0 Radio Resource Control (RRC) Protocol specification.

[11] Apple Push Notification Service https://developer.apple.com/notifications/.

[12] Google Cloud Messaging http://developer.android.com/google/gcm/index.html.

[17] Gupta, M. ; Jha, S.C. ; Koc, A.T. ; Vannithamby, R , “ Energy impact of emerging mobile internet applications on LTE networks: issues and solutions”, IEEE Communications Magazine, pp. 90-97, February 2013.

[21] 3GPP TS 36.211 V12.0.0, Evolved Universal Terrestrial Radio Access (E-UTRA),Physical Channels and Modulation