User Terminal Equipment Research Articles

A Caching-Based Dual K-Anonymous Location Privacy-Preserving Scheme for Edge Computing

Location-based services have become prevalent and the risk of location privacy leakage increases. Most existing schemes use third-party-based or third-party-free system architectures; the former suffers from a single point of failure (SPOF) and the latter experiences a heavy load on user terminal equipment and higher communication costs. Ensuring location privacy while lowering system overhead becomes a challenge. Many existing schemes fail to leverage the responses from a LBS server; such responses can be cached to answer subsequent queries. As a result, providing users with a relatively comprehensive level of location privacy protection is troublesome. In this article, we propose a caching-based dual K-anonymous (CDKA) location privacy preserving scheme in edge computing environments. Our scheme employs an edge server to intercedes between a user and LBS the server. We reduce the load on the user device by applying multi-level caching and to protect location privacy through dual anonymity. To ensure the location privacy in our construction, we set mobile clients and edge servers as anonymous. We use caching to lower the communication overhead and enforce the location privacy. The security analysis of our scheme supports its robustness against the edge server and the LBS server privacy offenses. We rely on the computation time, the communication cost and the cache hit ratio to evaluate our work against existing constructions. The results are two-fold: our work possesses a better response rate down to 15 ms to 32.6 ms and exhibits lower communication cost requirements down to 6.2 and 38.9 KB compared to existing works. Our scheme witnesses a higher cache hit ratio up to 13.6% and 39.1% compared to the literature.

Multisource Mobile Transfer Learning Algorithm Based on Dynamic Model Compression

With the development of the Internet of Things, the application of computer vision on mobile phones is becoming more and more extensive and people have higher and higher requirements for the timeliness of the recognition results returned and the processing capabilities of the mobile phone for image recognition. However, the processing capability and storage capability of the user terminal equipment cannot meet the needs of identifying and storing a large number of pictures, and the data transmission process will cause high energy consumption of the terminal equipment. At the same time, multisource deep transfer learning has outstanding performance in computer vision and image classification. However, due to the huge amount of calculation of the deep network model, it is impossible to use the existing excellent network model to realize image recognition and classification on the mobile terminal. In order to solve the abovementioned problems, we propose a multisource mobile transfer learning algorithm based on dynamic model compression, this algorithm considers the realization of multisource transfer learning computing in the case of multiple mobile device computing source domains, and the method also guarantees data privacy and security for each device (origin domain). Meanwhile, extensive experiments show that our method can achieve remarkable results in popular image classification datasets.

Evaluation Index of School Sports Resources Based on Artificial Intelligence and Edge Computing

As the demand for education continues to increase, the relative lack of physical resources has become a bottleneck hindering the development of school physical education to a certain extent. This research mainly discusses the evaluation index system of school sports resources based on artificial intelligence and edge computing. Human resources, financial resources, and material resources in school sports resources are the three major resources in resource science. University sports stadium information publicity uses Internet technology to establish a sports information management platform and mobile Internet terminals to optimize university sports resources and stadium information management services. It uses artificial intelligence technology to improve venue information management. It establishes a comprehensive platform for venue management information, collects multidimensional information, provides information resources and accurate information push, and links venue information with public fitness needs. Using edge computing to realize nearby cloud processing of video data, reduce the phenomenon of black screen jams during live broadcast, improve data computing capabilities, and reduce users’ dependence on the performance of terminal devices, build a smart sports resource platform, combine artificial intelligence (AI) to create smart communities, smart venues, and realize intelligent operations such as event service operations and safety prevention and control in important event venues. During the live broadcast of the student sports league, the nearby cloud processing of video data is realized in the form of edge computing, which improves the data computing ability and reduces the performance dependence on the user terminal equipment itself. In the academic survey of college physical education teachers, undergraduates accounted for 26.99%, masters accounted for 60.3%, and doctoral degrees accounted for 12.8%. This research will help the reasonable allocation of school sports resources.

Proposed ITU-R Compatible Inter-Site and Inter-Sector Interference Models for LTE-Advanced Networks

Cellular network deployment with three sectors per site and a frequency reuse factor of one is key to supporting high data rate applications in LTE Advanced Networks. However, such configurations result in increased inter-cell interference. In this paper we model the effects of inter-cell interference on an LTE-Advanced network at two carrier frequencies. We consider two urban environments and four cell ranges. The effects of inter-cell interference are separated into inter-site interference and inter-sector interference. A site-specific 3D ray-tracing tool is used to model the communication channel between the base stations (serving and interfering links) and the user equipment terminals. The inter-site interference is first modelled in terms of its dominant interference proportion and then validated using previously reported field measurements recorded in London (U.K.). Secondly, the inter-site and inter-sector interference components are modelled as a function of user equipment relative position from the serving base stations. Our approach is compatible with the standardized ITU-R model and our proposal can easily be added to these international models. Our model requires no system layout for the interferers and reduces the required channel generation time by a factor of 12 compared with the system layout method.

Differential Phase-Shift QKD in a 2:16-Split Lit PON with 19 Carrier-Grade Channels

We investigate the practical network integration of differential phase shift quantum key distribution following a cost-optimized deployment scheme where complexity is off-loaded to a centralized location. User terminal equipment for quantum state preparation at 1 GHz symbol rate is kept technologically lean through use of a directly-modulated laser as optical encoder. Integration in a passive optical network infrastructure is experimentally studied for legacy and modern optical access standards. We analyze the implications that result from Raman scattering arising from different spectral allocations of the classical channels in the O-, S-, C- and L-band, and prove that the quantum channel can co-exist with up to 19 classical channels of a fully-loaded modern access standard. Secure-key generation at a rate of 5.1 times 10e-7 bits per pulse at a quantum bit error ratio of 3.28 percent is obtained over a 13.5 km reach, 2 to 16 split passive network configuration. The high power difference of 93.8 dB between launched classical and quantum signals in the lit access network leads to a low penalty of 0.52 percent in terms of error ratio.

A calculation method of user response potential on demand side response in integrated energy system

The current Integrated Demand Response (IDR) strategies cannot accurately evaluate the user’s maximum response which ignore the user terminal equipment response model. At the same time, the optimization target of the current IDR strategies is mostly electric energy, and other energy response requirements such as natural gas are not considered. This paper establishes an IDR strategy model based on energy models for different equipment terminals of residential users. And calculate the theoretical maximum response potential value of different users according to the response strategy formulated by different energy response requirements with the GA-SQP hybrid algorithm. The example analyses the user response potential in typical scenarios and time periods. The results verify the effectiveness and feasibility of the proposed method.

Development of GPS Positioning and Navigation Software System Based on VC++

With the rapid development of China’s economy, the field positioning and navigation technology has also been continuously developed. The global positioning system(GPS), can provide fast and accurate positioning and navigation for exploration operations in desert areas. In this paper, the developed GPS navigation and positioning software system solves the problem of cooperation between GPS user terminal equipment and exploration site. It also effectively combines image processing, data transmission, data processing, error analysis and other technologies to achieve the goals such as data recording and transmission, field navigation, data browsing and query, coordinate transformation, error analysis, and printing curve. After field test work and post-data processing, the software proved to have the following advantages: convenient operation, accurate coordinate transformation and complete functions. It could meet the requirements for accurate GPS positioning and navigation of the field exploration. Its practical effect is good and can provide reference for future field exploration and navigation mapping.

Comparative Study of Power Saving and Delay in LTE DRX, Directional-DRX and Hybrid-Directional DRX

With integration of advanced long term evolution networks (LTE networks) in mobile technology, 5G networks are introduced due to broadband spectrum extension which requires higher power consumption. Discontinuous reception (DRX) sleep mode mechanism is provided to accommodate lower power consumption of user equipment terminals (UEs). For mmWave directional communication air interface in LTE between UE and LTE eNB, UE performs beam searching and alignment with LTE eNB (4G base station) after every short/long DRX cycle during ON duration. Dual connectivity of UE to both LTE eNB and NR NodeB (5G New RAN base station) is a hybrid-directional system. This allows us to propose a sleep mode mechanism which is called hybrid directional-DRX (HD-DRX). In HD-DRX, UE performs beam searching and alignment with NR NodeB during ON duration only if data packet intimation. A semi-Markov chain process is introduced to describe UE state transition. Depending on this chain, power saving factor and average delay are calculated. HD-DRX power saving as compared to LTE DRX and Directional-DRX (D-DRX) is conducted. Due to different beam searching procedure, another comparison of average delay is assigned between D-DRX and HD-DRX. Data traffic model parameters are considered and numerical analysis is validated using MATLAB program simulations.

Interference Management in 5G Reverse TDD HetNets With Wireless Backhaul: A Large System Analysis

This work analyzes a heterogeneous network (HetNet), which comprises a macro base station (BS) equipped with a large number of antennas and an overlaid dense tier of small cell access points (SCAs) using a wireless backhaul for data traffic. The static and low mobility user equipment terminals (UEs) are associated with the SCAs while those with medium-to-high mobility are served by the macro BS. A reverse time division duplexing (TDD) protocol is used by the two tiers, which allows the BS to locally estimate both the intra-tier and inter-tier channels. This knowledge is then used at the BS either in the uplink (UL) or in the downlink (DL) to simultaneously serve the macro UEs (MUEs) and to provide the wireless backhaul to SCAs. A concatenated linear precoding technique employing either zero-forcing (ZF) or regularized ZF is used at the BS to simultaneously serve MUEs and SCAs in DL while nulling interference toward those SCAs in UL. We evaluate and characterize the performance of the system through the power consumption of UL and DL transmissions under the assumption that target rates must be satisfied and imperfect channel state information is available for MUEs. The analysis is conducted in the asymptotic regime where the number of BS antennas and the network size (MUEs and SCAs) grow large with fixed ratios. Results from large system analysis are used to provide concise formulae for the asymptotic UL and DL transmit powers and precoding vectors under the above assumptions. Numerical results are used to validate the analysis in different settings and to make comparisons with alternative network architectures.

Joint Scheduling and Resource Allocation with Fairness Based on the Signal-to-Leakage-plus-Noise Ratio in the Downlink of CoMP Systems

Recent research has shown that coordinated multi point (CoMP) transmission can provide significant gains in terms of the overall cell capacity and cell-edge user throughput [1]. The main purpose of this paper is to enhance the overall cell throughput, the cell-edge user’s throughput, and the fairness among user equipment terminals (UEs) in LTE-Advanced (LTE-A) systems using CoMP. Towards that end, we propose two novel resource allocation (RA) strategies based on the Signal-to-Leakage-plus-Noise-Ratio (SLNR) for the downlink of CoMP transmission in LTE-A systems. The proposed RA strategies select the UEs that can efficiently share the same resource block (RB) without degrading the overall throughput by using the SLNR metric. Moreover, a fairness algorithm is proposed to achieve certain level of fairness among the UEs and to improve the cell-edge UEs throughput. In addition, we compare the proposed strategies to the RA based on the more common Signal-to-Interference-plus-Noise-Ratio (SINR) strategy. The SLNR-based RA is shown to provide significant gains in throughput reaching up to 80 % in the overall system and is shown to have even less complexity than the typical SINR-based RA. Moreover, by evaluating the proposed strategies in terms of the average cell throughput, cell-edge user throughput, and fairness among UEs, simulations show that the proposed strategies present superior performance compared to the more common SINR strategy. With such advantages as enhanced throughput and lower complexity, the proposed schemes are suitable for application in practical cellular systems.

글로벌스타 위성 모뎀을 위한 임베디드 프로세서 기반 PPP(Point-to-Point Protocol) 구현

본 논문에서는 운영체제에서 지원하는 PPP 프로그램이 없는, 즉 별도의 운영체제를 사용하지 않는 임베디드 시스템에서 글로벌스타 인공위성 모뎀을 이용하기 위한 PPP 프로그램을 작성하였다. 글로벌스타를 포함한 오브컴, 인말샛과 같은 많은 위성통신 시스템은 데이터 링크 구현을 위하여 그 자체의 인터페이스를 제공하고 있다. 글로벌스타 위성 시스템과 데이터 링크를 구현하기 위해서는 글로벌스타 위성에서 사용하는 PPP를 사용해야 한다. 따라서 본 논문에서는 임베디드 프로세서 기반의 PPP를 구현하였으며, 이와 더불어 사용자 단말 장치를 개발하였다. 사용자 단말 장치는 다양한 응용분야에 사용될 수 있도록 여러 가지 입출력 장치 및 센서를 장착하여 설계 및 실현하였다. 실험 테스트를 통하여 이와 같이 구축된 모든 시스템은 글로벌스타 데이터 링크를 통해서 잘 동작함을 확인한다. In this paper, we programed the PPP(Point-to-Point Protocol) used in embedded application environments for Globalstar Satellite Modem. There are number of satellite communication systems such as Orbcomm, Globalstar, Inmarsat and etc. But each satellite data service have provided a communication interface only for their own data links. A data communication link is needed to communicate with Globalstar satellite service. Globalstar communication system uses PPP to establish data communication link, so we implemented the embedded processor based PPP protocol. The user terminal equipment also designed in this paper has various input/output devices and sensors applicable to any user specific application. The proposed PPP program works well with Globalstar data communication link through experimental tests.

Cognitive Radio: A Communications Engineering View

Cognitive radio is an emerging technology that enables the flexible development, construction, production, shipping, and deployment of highly adaptive radios that are built upon software defined radio technology. This contribution starts with a brief section that underlines the paramount importance of the mobile radio communications channel. Then, spectrum issues are discussed to emphasize the reasons for spectrum scarcity as well as the importance of dynamic spectrum allocation. Some remarks about the development of software defined radio from digital radio lead to a discussion of the most important engineering aspects of CR, for example, location and spectrum awareness, transmission power control, and signal analysis. Because usually papers about CR are somewhat visionary, we first describe practical steps to an implementation of helpful CR properties into a mobile communication base station, as well as user terminal equipment. The article concludes with a short summary.

Traffic control at terminal equipment in ATM networks using cryptographic techniques

The usage parameter control (UPC) function, which monitors and controls user traffic to protect network resources from both malicious and unintentional misbehaviour, is an important task for ATM networks in performing congestion control procedures. The scheme performing the UPC function is usually called a ‘control scheme’ or ‘policing scheme’. No matter what scheme is employed, the cell delay variation (CDV) that comes before the scheme makes it difficult to police user traffic accurately as long as it is located at the edge node of the public network 1–10. In this paper, we propose an architecture where the network can perform the UPC function at a user's terminal equipment, in order to overcome the CDV problem. With this feature, the network can control user traffic more accurately. Applying cryptographic techniques, we also propose a signalling protocol to support this architecture.