Topic 1:

Intelligent resource management and service provisioning for open radio access networks (O-RAN)

Mobile networks have seen more than a thousand times traffic increases in the past decade. Network operators face an ever increasing demand and cost to deploy denser networks in order to maintain the quality of services. In view of this paradigm shift, we present an open cloud radio access network (O-RAN/C-RAN) service model in this work. Integrating the cross-layer functions of spectrum resource sharing, channel and power allocation, and interference management in an O-RAN/C-RAN architecture, we explore the feasibility of providing a scalable yet efficient broadband wireless service with dense small cell networks (DSN). The proposed methods and architecture can be applied to DSN that support the functions of (further enhanced) inter-cell interference cancelation (feICIC/ICIC) techniques of 3GPP standard, and have the potential to provide a cost-effective solution for high-quality DSN. Simulation results across an area of 100 km2 show that the proposed scheme can offer an aggregate downlink throughput of 21 Gbps over a maximum channel bandwidth of 20 MHz, which is 5 times the throughput with a typical ICIC method, making it a promising and cost-effective solution for future broadband wireless services. The related research papers are listed as follows:

本研究專注在開放無線接取網路 (Open Radio Access Network, O-RAN) 與雲端接取網絡 (Could RAN, C-RAN) 架構下，提出一新穎之通訊服務模型，如圖所示，用以在密集小細胞網絡 (Dense Small Cell Network, DSN) 中提供高品質的通訊服務。為達成此目標，我們將頻譜資源共享、通道和功率分配以及干擾管理的跨層功能集成到 O-RAN/C-RAN 架構中，並藉由 DSN密集佈建的小基地台，提供可擴展且高效的寬頻無線通訊。所提出的方法和服務模型可以相容於支持 3GPP 標準的干擾控制機制，例如：feICIC/ICIC技術，具有作為DSN資源管理系統實作之可行性。根據大區域的模擬顯示，在跨越 100 平方公里的區域中，所提出的方法可以在單一電信營運商所擁有的 20 MHz頻譜資源下提供 21 Gbps 的下行通道吞吐量，相較典型 ICIC 方法的模擬結果，本研究提出的方法可以達到 5 倍的通訊增益，這顯示我們提出的方案對未來寬頻無線服務是一個頗具希望的高效益解決方案。相關論文發表如下：

S.-H. Wu, C.-H. Ko, and H.-L. Chao, “On-Demand Coordinated Spectrum and Resource Provisioning under an Open C-RAN Architecture for Dense Small Cell Networks,” early access on IEEE Trans. on Mobile Computing, Oct. 2022. (Link)
S. -H. Wu et al., “A cloud model and concept prototype for cognitive radio networks, ” in IEEE Wireless Communications, vol. 19, no. 4, pp. 49-58, August 2012. (Link)
S. -H. Wu, H. -L. Chao, C. -H. Ko, S. -R. Mo, C. -F. Liang and C. -C. Cheng, "Green Spectrum Sharing in a Cloud-Based Cognitive Radio Access Network," in 2013 IEEE International Conference on Green Computing and Communications and IEEE Internet of Things and IEEE Cyber, Physical and Social Computing, Beijing, China, 2013, pp. 276-281 (Link)

Topic 2:

WiSDON RAN Intelligent Controller

WiSDON lab has been dedicated to the development of advanced management functions based on WiSDON RAN intelligent controller (RIC). These functions emcompass network energy management, beam management, location management, mobility management, and slicing management. Leveraging the digital twin technology, WiSDON lab aims to streamline the development and evaluation process of these management functions by integrating AI/ML algorithms into various applications, such as indoor positioning, throughput prediction, mobily load balancing, mobility robustness optmization, power control, MIMO selection, QoS-based network energy saving (NES), RAN slicing and RIS-asssisted RIC.

Topic 3:

Green O-RAN by Network Digital Twin

Among the aforementioned advanced RIC features powered by WiSDON lab, QoS-based NES is the most eye-catching and urgently needed function. This function relies on digital twin technology to estimate the location of UEs in indoor environments based on the received signal strengths from multiple nearby gNBs. It accurately predicts the throughput of UEs before handover occurs, and ensures communication quality after handover. UEs are handed over from lightly loaded gNBs to neighboring gNBs, followed by shutting down the former gNBs to save energy, all while maintaining communication quality for the UEs. This functionality can be demonstrated by the following videos.

Video1
Video2
Slides: pdf, powerpoint


 

Journals

• S.-H. Wu, C.-H. Ko, and H.-L. Chao, “On-Demand Coordinated Spectrum and Resource Provisioning under an Open C-RAN Architecture for Dense Small Cell Networks,” early access on IEEE Trans. on Mobile Computing, Oct. 2022.
• S.-H. Wu and G.-Y. Lu, “Compressive Beam and Channel Tracking with Reconfigurable Hybrid Beamforming in mmWave MIMO OFDM Systems,” early access on IEEE Trans. on Wireless Communications, vol. 22, no. 2, pp. 1145-1160, Sept. 2022. 
• C.-H. Ko and S.-H. Wu, "A Framework for Proactive Indoor Positioning in Densely Deployed WiFi Networks,” IEEE Trans. on Mobile Computing, vol. 21, no. 1, pp. 1-15, Jan. 2022.
• K.-T. Feng, L.-H. Shen, C.-Y. Li, P.-T. Huang, S.-H. Wu, L.-C. Wang, Y.-B. Lin, and M.-C. F. Chang, "3D On-Demand Flying Mobile Communication for Millimeter Wave Heterogeneous Networks,” IEEE Network Magazine, vol. 34, no. 5, pp. 198-204, March 2020.
• C.-K. Tseng, S.-H. Wu, H.-L. Chao, T. Q. S. Quek, and C.-H. Gan "Effective service architecture and antenna allocation mechanism for CoMP transmissions in ultra dense networks,” IEEE Trans. on Wireless Communications, vol. 18, no. 9, pp. 4283-4297, Sept. 2019.
• C.-K. Tseng and S.-H. Wu, "Selective and opportunistic AF relaying for cooperative ARQ: An MLSD perspective,” IEEE Trans. on Communications, vol. 67, no. 1, pp. 124-139, Jan. 2019.
• H.-L. Chiu and S.-H. Wu, "Cross-Layer performance analysis of cooperative ARQ with opportunistic multi-point relaying in mobile networks,” IEEE Trans. on Wireless Communications, vol. 17, no. 6, pp. 4191-4205, June, 2018.
• C.-K. Tseng and S.-H. Wu, "Effective protocols and channel quality control mechanisms for cooperative ARQ with opportunistic AF relaying,” IEEE Trans. on Vehicular Technology, vol. 67, no. 3, pp. 2382-2397, March, 2018.
• S.-H. Wu, L.-K. Chiu, and J.-W. Wang, "Reconfigurable hybrid beamforming for dual-polarized mmWave MIMO channels: Stochastic channel modeling and architectural adaptation methods,” IEEE Trans. on Communications, vol. 66, no. 2, pp. 741-755, Feb. 2018.
• S.-H. Wu, H.-L. Chiu, and J.-H. Li "Effectiveness and relay efficiency of opportunistic multipoint relaying on cooperative ARQ,” IEEE Trans. on Vehicular Technology, vol. 66, no. 6, pp. 4781-4796, June, 2017.
• D.-H. Huang, S.-H. Wu, W.-R. Wu, and P.-H. Wang, "Cooperative radio source positioning and power map reconstruction: A sparse Bayesian learning approach,” IEEE Trans. on Vehicular Technology, vol. 64, no. 6, pp. 2318-2332, June, 2015.
• L.-K. Chiu and S.-H. Wu, "An effective approach to evaluate the training and modeling efficacy in MIMO time-varying fading channels,” IEEE Trans. on Communications, vol. 64, no. 1, pp. 140-155, Jan. 2015.
• S.-H. Wu, L.-K. Chiu, K.-Y. Lin and T.-H. Chang, "Robust hybrid beamforming with phased antenna arrays for downlink SDMA in indoor 60GHz channels” IEEE Trans. on Wireless Communications, vol. 12, no. 9, pp. 4542-4557, Sept. 2013.
• S.-H. Wu, H.-L. Chao, C.-H. Ko, S.-R. Mo, C.-T. Jiang, T.-L. Li, C.-C. Cheng and C.-F. Liang, “A Cloud model and concept prototype for cognitive radio networks,” IEEE Wireless Communications Magazine, special issue on Cognitive Radio Networks: vol. 19, no. 4, pp. 49-58, Aug. 2012.
• C.-I. Kuo, S.-H. Wu and C.-K. Tseng, “Robust linear beamformer designs for coordinated multi-point AF relaying in downlink multi-cell networks,” IEEE Trans. on Wireless Communications, vol. 11, no. 9, pp. 3272-3283, Sept. 2012.
• L.-C. Wang, W.-C. Liu and S.-H. Wu, “Analysis of diversity-multiplexing tradeoff in a cooperative network coding system," IEEE Trans. on Communications, vol. 59, no. 9, pp. 2373-2376, Sept. 2011.
• S.-H. Wu, C.-Y. Yang and D.-H. Huang, "Cooperative sensing of wideband cognitive radio: A multiple hypotheses testing approach," IEEE Trans. on Vehicular Technology, special issue on “Achievements and the Road Ahead: The First Decade of Cognitive Radio”, vol. 59, no. 4, pp. 1835-1846, May, 2010
• S.-H. Wu, U. Mitra and C.-C. J. Kuo, "Iterative joint channel estimation and multiuser detection for DS-CDMA in frequency-selective fading channels," IEEE Trans. on Signal Processing, vol. 56, no. 7, pp. 3261-3277, July, 2008.
• S.-H. Wu, U. Mitra and C.-C. J. Kuo, "Performance of linear reduced-rank multistage receivers for DS-CDMA in frequency-selective fading channels," IEEE Trans. on Information Theory, vol. 51, no. 10, pp. 3493-3517, Oct. 2005.
• S.-H. Wu, U. Mitra and C.-C. J. Kuo, "Reduced-Rank multistage receivers for DS-CDMA in frequency-selective fading channels," IEEE Trans. on Communications, vol. 53, no. 2, pp. 366-378, Feb. 2005. 

Conference Papers

• S.-H. Wu, C.-H. Ko, and H.-L. Chao, “On-Demand Coordinated Spectrum and Resource Provisioning under an Open C-RAN Architecture for Dense Small Cell Networks,” early access on IEEE Trans. on Mobile Computing, Oct. 2022.
• S.-H. Wu and G.-Y. Lu, “Compressive Beam and Channel Tracking with Reconfigurable Hybrid Beamforming in mmWave MIMO OFDM Systems,” early access on IEEE Trans. on Wireless Communications, vol. 22, no. 2, pp. 1145-1160, Sept. 2022.