Kaisa Zhang

Dr. Kaisa Zhang

orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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15 March 2019 in EURASIP Journal on Wireless Communications and Networking
Verified
Journal Article
Open access
PDF file
KZKaisa Zhang
Kaisa Zhang
GCGang Chuai
Gang Chuai
WGWeidong Gao
Weidong Gao
XLXuewen Liu
Xuewen Liu
SMSaidiwaerdi Maimaiti
Saidiwaerdi Maimaiti
ZSZhiwei Si
Zhiwei Si
With the development of wireless devices and the increase of mobile users, the operator’s focus has shifted from the construction of the communication network to the operation and maintenance of the network. Operators are eager to know the behavior of mobile networks and the real-time experience of users, which requires the using of historical data to accurately predict future network conditions. Big data analysis and computing which is widely adopted can be used as a solution. However, there are still some challenges in data analysis and prediction for mobile network optimization, such as the timeliness and accuracy of the prediction. This paper proposes a traffic analysis and prediction system which is suitable for urban wireless communication networks by combining actual call detail record (CDR) data analysis and multivariate prediction algorithms. Firstly, a spatial-temporal modeling is used for historical traffic data extracting. After that, causality analysis is applied to communication data analysis for the first time. Based on causal analysis, multivariate long short-term memory models are used to predict future data for CDR data. Finally, the prediction algorithm is used to process real data of different scenes in the city to verify the performance of the entire system.

16 March 2022 in Remote Sensing
Verified
Journal Article
Open access
PDF file
KZKaisa Zhang
Kaisa Zhang
GCGang Chuai
Gang Chuai
JZJinxi Zhang
Jinxi Zhang
XCXiangyu Chen
Xiangyu Chen
ZSZhiwei Si
Zhiwei Si
SMSaidiwaerdi Maimaiti
Saidiwaerdi Maimaiti
The development of technology has strongly affected regional urbanization. With development of mobile communication technology, intelligent devices have become increasingly widely used in people’s lives. The application of big data in urban computing is multidimensional; it has been involved in different fields, such as urban planning, network optimization, intelligent transportation, energy consumption and so on. Data analysis becomes particularly important for wireless networks. In this paper, a method for analyzing cellular traffic data was proposed. Firstly, a method to extract trend components, periodic components and essential components from complex traffic time series was proposed. Secondly, we introduced causality data mining. Different from traditional time series causality analysis, the depth of causal mining was increased. We conducted causality verification on different components of time series and the results showed that the causal relationship between base stations is different in trend component, periodic component and essential component in urban wireless network. This is crucial for urban planning and network management. Thirdly, DIC-ST: a spatial temporal time series prediction based on decomposition and integration system with causal structure learning was proposed by combining GCN. Final results showed that the proposed method significantly improves the accuracy of cellular traffic prediction. At the same time, this method can play a crucial role for urban computing in network management, intelligent transportation, base station siting and energy consumption when combined with remote sensing map information.

24 June 2024 in Aerospace
Verified
Journal Article
Open access
PDF file
HYHaizhi Yu
Haizhi Yu
WGWeidong Gao
Weidong Gao
KZKaisa Zhang
Kaisa Zhang
Amidst the escalating need for stable power supplies and high-quality communication services in remote regions globally, due to challenges associated with deploying a conventional power communication infrastructure and its susceptibility to natural disasters, LEO satellite networks present a promising solution for broad geographical coverage and the provision of stable and high-speed communication services in remote regions. Given the necessity for frequent handovers to maintain service continuity, due to the high mobility of LEO satellites, a primary technical challenge confronting LEO satellite networks lies in efficiently managing the handover process between satellites, to guarantee the continuity and quality of communication services, particularly for power services. Thus, there is a critical need to explore satellite handover optimization algorithms. This paper presents a handover optimization scheme that integrates deep reinforcement learning (DRL) and graph neural networks (GNN) to dynamically optimize the satellite handover process and adapt to the time-varying satellite network environment. DRL models can effectively detect changes in the topology of satellite handover graphs across different time periods by leveraging the powerful representational capabilities of GNNs to make optimal handover decisions. Simulation experiments confirm that the handover strategy based on the fusion of message-passing neural network and deep Q-network algorithm (MPNN-DQN) outperforms traditional handover mechanisms and DRL-based strategies in reducing handover frequency, lowering communication latency, and achieving network load balancing. Integrating DRL and GNN into the satellite handover mechanism enhances the communication continuity and reliability of power systems in remote areas, while also offering a new direction for the design and optimization of future power system communication networks. This research contributes to the advancement of sophisticated satellite communication architectures that facilitate high-speed and reliable internet access in remote regions worldwide.

8 April 2024 in IEEE Network
Verified
Journal Article
Closed access
QLQian Liu
Qian Liu
SWSihong Wang
Sihong Wang
ZQZhi Qi
Zhi Qi
KZKaisa Zhang
Kaisa Zhang
QLQilie Liu
Qilie Liu
Integrating terrestrial and non-terrestrial networks can provide a wide area of Internet of Things (IoT) services with global connections and ubiquitous communications. However, integrated terrestrial and non-terrestrial networks (ITNTNs) also face huge challenges caused by complex environments, diverse services, and heterogeneous nodes. By leveraging the powerful driving force of edge intelligence (EI) technology for network development, a framework named “ITNTNs with EI” is proposed in this paper as the solution to the challenges above. We design system architecture, dynamic edge resource deployment, and intelligent edge model training for the proposed framework and discuss its application scenarios, challenges, and some open research issues. Then, simulation experiments about a joint computation offloading and resource allocation optimization algorithm based on the DRL-based model are conducted for a specific framework instance. The results demonstrate that optimization management solutions driven by EI can provide faster response and greater quality of service for IoT applications in ITNTNs.

18 August 2023 in IEEE Transactions on Network and Service Management
Verified
Journal Article
Closed access
YHYijian Hou
Yijian Hou
KZKaisa Zhang
Kaisa Zhang
XLXuewen Liu
Xuewen Liu
GCGang Chuai
Gang Chuai
WGWeidong Gao
Weidong Gao
XCXiangyu Chen
Xiangyu Chen
The slice-based Open Radio Access Network (O-RAN) enables rapid deployment of logical networks and provides personalized services. In designing the inter-slice resource sharing scheme, multiple factors need to be considered. Firstly, resource isolation level (RIL) and interference isolation level (IIL) are two key factors in ensuring slice isolation. Secondly, the new business models brought by network slicing imply the need to consider tenants’ resource costs. However, to date, no prior studies have considered RIL, IIL and costs simultaneously, often involving only one or two of them. Accordingly, we propose an inter-slice resource block (RB) leasing and association adjustment scheme (ISRLA) that allows slices to borrow RBs from the shared resource pool and other slices. ISRLA is divided into three modules, namely, prediction module, leasing module, and RB association adjustment module. Firstly, the prediction module uses a Long Short-Term Memory model to predict RB demand and guide subsequent resource optimization. Then, the leasing module balances RIL and costs to determine the number of RBs to be leased in or leased out. This is defined as a non-linear integer programming problem, which is solved through an iterative strategy based on camp swapping (ISBCS). ISBCS is further proven to be convergent. Finally, the RB association adjustment module determines specific RB adjustment strategies based on the results obtained from the leasing module, aiming to ensure IIL. Here, we design a potential game based on the Lagrangian relaxation (LR) method to obtain an approximate optimal solution while reducing computational complexity. Compared with camp enumeration (CE), solver (MOSEK), and genetic algorithm (GA), the proposed ISRLA reduces simulation time by up to 84%, 95%, and 99%, respectively. When the number of slices is 4, the performance of ISRLA is the same as that of CE. Moreover, the IIL gap between ISRLA and MOSEK is less than 4.5%. The simulation results show that the proposed ISRLA can obtain the approximate optimal solution with low computational complexity.

19 September 2023 in Drones
Verified
Journal Article
Open access
PDF file
XLXuewen Liu
Xuewen Liu
SHShuman Huang
Shuman Huang
KZKaisa Zhang
Kaisa Zhang
SMSaidiwaerdi Maimaiti
Saidiwaerdi Maimaiti
GCGang Chuai
Gang Chuai
PZPeiliang Zuo
Peiliang Zuo
Relay-aided Device-to-Device (D2D) communication combining visible light communication (VLC) with radio frequency (RF) is a promising paradigm in the internet of things (IoT). Static relay limits the flexibility and maintaining connectivity of relays in Hybrid VLC/RF IoT systems. By using a drone as a relay station, it is possible to avoid obstacles such as buildings and to communicate in a line-of-sight (LoS) environment, which naturally aligns with the requirement of VLC Systems. To further support the application of VLC in the IoT, subject to the challenges imposed by the constrained coverage, the lack of flexibility, poor reliability, and connectivity, drone relay-aided D2D communication appears on the horizon and can be cost-effectively deployed for the large-scale IoT. This paper proposes a joint resource allocation and drones relay selection scheme, aiming to maximize the D2D system sum rate while ensuring the quality of service (QoS) requirements for cellular users (CUs) and D2D users (DUs). First, we construct a two-phase coalitional game to tackle the resource allocation problem, which exploits the combination of VLC and RF, as well as incorporates a greedy strategy. After that, a distributed cooperative multi-agent reinforcement learning (MARL) algorithm, called WoLF policy hill-climbing (WoLF-PHC), is proposed to address the drones relay selection problem. Moreover, to further reduce the computational complexity, we propose a lightweight neighbor–agent-based WoLF-PHC algorithm, which only utilizes historical information of neighboring DUs. Finally, we provide an in-depth theoretical analysis of the proposed schemes in terms of complexity and signaling overhead. Simulation results illustrate that the proposed schemes can effectively improve the system performance in terms of the sum rate and outage probability with respect to other outstanding algorithms.