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In 5G mobile networks, the convergence of cloud computing and communication leads to mobile edge computing, benefiting vehicular networks. However, the advent of a wide variety of new services and devices has changed the vehicular network landscape, challenging vehicle-to-network services' migrations. In this paper, we focus on optimizing long-term average latency of multiple services with a different quality of services (QoS). We first introduce an offline algorithm, which can be used to find the optimal migration strategy of services. Then, we analyze the negative effect of trajectory prediction and suggest an optimizing method to reduce this effect by partial updating. Finally, based on this method, we propose a partial dynamic optimization algorithm to approximate the optimal solution, by integrating the priority queue, which utilizes QoS information. We simulate the average service latency, confirming that the proposed partial dynamic optimization algorithm keeps a stable service latency and performs better than other existing algorithms, considering the negative effect of trajectory prediction. We also verify that the proposed algorithm can meet the low latency requirement of the vehicles and the different demands of different services. Besides, the partial dynamic optimization algorithm has a lower time complexity. INDEX TERMS Mobile edge computing, migration strategy, quality of services, vehicle to network services.

In this paper, we propose a W-band 8-quadrature-amplitude-modulation (8QAM) frequency tripling photonic vector millimeter-wave (mm-wave) signal generation method by using a phase modulator (PM) with only amplitude pre-coding. The PM is driven by 2-Gbaud 8QAM-modulated amplitude precoded signal at 25 GHz. Instead of phase pre-coding, we only need to reverse the real part of the signal at the receiver after photo detector (PD). The structure of the transmitter and the structure of the receiver are simple. The frequency tripling scheme is completed by numerical simulation, the output optical spectrum is consistent with the theoretical analysis, and bit-error-ratio (BER) curves indicate that the put forward 75 GHz 8QAM vector signal generation technique has good performance. The BER of 6 Gbit/s 75 GHz 8QAM vector mm-wave signal is below 3.8 × 10 −3 after 12 km optical fiber transmission. For all we know, it is the first time to report on the generation of high-order QAM photonic mm-wave signal with odd times of RF frequency by using a single external modulator. INDEX TERMS Millimeter wave, frequency multiplication, phase modulation, digital signal processing, quadrature amplitude modulation. LUN ZHAO received the M.S. degree in communication and information system from the Wuhan Research Institute (WRI), Hubei, China, in 2012, and the Ph.D. degree in electronic science and technology from the School of electronic engineering, Beijing University of Posts and Telecommunications, Beijing, China, in 2016. He is currently working in information and telecommunication engineering with the Ubiquitous Wireless Communication Technology Team, Chongqing University of Posts and Telecommunications. His research interests include radio over fiber, coherent optical communication, machine learning/deep learning in optical communication, optical physical layer security, and 5G mobile networks. LIAN XIONG was born in Huanggang, Hubei, China, in 1985. He received the B.S. degree in telecommunications engineering from the North University of China, Taiyuan, China, in 2008, the M.S. degree in communication and information system from the Taiyuan University of Technology, Taiyuan, in 2011, and the Ph.D. degree in communication and information system from

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