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Wuhan Research Institute Of Post And Telecommunications and Fiberhome Telecommunication Technologies Co. | Date: 2017-03-15

A low-loss few-mode fiber relates to the technical field of optical communications and related sensing devices, and includes, from inside to outside, a core layer (1), a fluorine-doped quartz inner cladding (2), a fluorine-doped quartz second core layer (3), a fluorine-doped quartz depressed cladding (4) and a fluorine-doped quartz outer cladding (5); germanium element is not doped within the core layer (1), the refractive index of the core layer (1) is in gradient distribution, and the distribution is a power-exponent distribution; the maximum value of difference in relative refractive index between the core layer (1) and the fluorine-doped quartz inner cladding (2) is 0.3% to 0.9%; the relative refractive index difference of the fluorine-doped quartz inner cladding (2) with respect to synthetic quartz is -0.3% to -0.5%; the difference in relative refractive index between the fluorine-doped quartz second core layer (3) and the fluorine-doped quartz inner cladding (2) is 0.05% to 0.2%; the difference in relative refractive index between the fluorine-doped quartz depressed cladding (4) and the fluorine-doped quartz inner cladding (2) is -0.1% to -0.5%; the relative refractive index difference of the fluorine-doped quartz outer cladding (5) with respect to synthetic quartz is -0.3% to -0.5%. The transmission loss of optical signals of the linear polarization modes that are supported by the few-mode fiber and the relay cost are reduced.


Ning Y.,CAS Shenzhen Institutes of Advanced Technology | Li L.,Wuhan Research Institute of Post and Telecommunications | Zhao G.,CAS Shenzhen Institutes of Advanced Technology
EAI Endorsed Transactions on Energy Web | Year: 2016

Accurate and real-time tracking of the orientation or attitude of rigid bodies has traditional applications in robotics, aerospace, underwater vehicles, human body motion capture, etc. Towards human body motion capture, especially wearable devices, the use of a longer time has always been a challenge for several weeks or several months continuously, so a low-cost chip and a low computational cost algorithm are necessary .The paper presented a quaternion-based algorithm that integrated the sensor output with the Kalman filtering algorithm, and a low power consumption Inertial Measurement Unit (IMU) for the attitude estimation. The low power consumption IMU with an inner Digital Motion Processor(DMP) from InvenSense Inc. called MPU9150, which contains triaxial accelerometers, triaxial gyroscopes, triaxial magnetometers and inner DMP. Firstly, we got attitude quaternion from DMP, and used the factored quaternion algorithm (FQA) to calculate course angle quaternion component. Then the Kalman Filtering algorithm was used to mix them together to acquire the accurate and good real-time performance attitude .The experimental results showed that Kalman filtering algorithm to mix DMP output and magnetometers data have better performance than gradient descent algorithm and complementary filter algorithm even in static performance and dynamic performance and power consumption.


Qi N.,Oregon State University | Qi N.,CAS Institute of Semiconductors | Xiao X.,Wuhan Research Institute of Post and Telecommunications | Hu S.,Fudan University | And 6 more authors.
IEEE Journal on Selected Topics in Quantum Electronics | Year: 2016

This paper discusses the design considerations of Silicon-based Mach-Zehnder Modulator (MZM) transmitters, consisting of the design of a Si-Photonic MZI modulator and a CMOS-based modulator driver. III-V and silicon-photonic MZMs are compared with respect to electrode design, driving scheme, and velocity matching. A 25-Gb/s hybrid-integrated silicon photonic MZM transmitter is then demonstrated, composed of a 65-nm bulk-CMOS driver directly wire bonded to a 180-nm SOI-CMOS MZM. The driver employs push-pull unit cells to save approximately 40% dc power while delivering 6.4 VPP differential swing to the modulator. Multiple driver cells are distributed along artificial on-chip transmission-lines, extending the bandwidth by 6 times. The lateral PN-interleaved MZM is designed and optimally biased to reach a balance of high-speed with acceptable optical extinction ratio (ER). Experimental results show that the fully assembled Si-Photonic transmitter (including PCB and wire-bonding losses) achieves approximately 11-GHz bandwidth, 6.4 VPP differential output swing, clean 25-Gb/s optical eye diagrams with 4-dB ER, and 520-mW dc power. © 2016 IEEE.


Zhang Y.,Wuhan Textile University | Xiao S.,Wuhan Textile University | Li J.,Wuhan Textile University | Wang J.,Wuhan Textile University | And 2 more authors.
International Journal of Multimedia and Ubiquitous Engineering | Year: 2016

According to the recently published report by the Federal Communications Commission, the spectrum regulatory authority in the United States, traffic distribution across the radio spectrum is extremely uneven. The phenomenon can be utilized to improve the multimedia content sharing. This paper proposesa novel model of multimedia sharingin wireless communication networks. The proposed multimedia sharing mechanis moffer services to users who want to access the multimedia networks. At the same time, it does not affect the QoS of existing paying users. The numerical results show that the proposed sharing mechanism provides higher throughput and quality of service than the existing system. © 2016 SERSC.


Zhang Y.,Wuhan Textile University | Hao F.,Wuhan University | Li J.,Wuhan Textile University | Wang J.,Wuhan Textile University | And 4 more authors.
2015 12th International Computer Conference on Wavelet Active Media Technology and Information Processing, ICCWAMTIP 2015 | Year: 2015

With network coding, data flows from the source to the destinations may be jointly coded in some intermediate nodes to achieve the maximum network capacity. There is scarcely any theory to systematically model and evaluate the loss of network coding. Without such a theory, the analysis of network coding under various settings is far from practical. To fill the vacancy, we introduce a loss model into network coding through the theory of stochastic network calculus. In order to obtain an ideal loss model, we deduce the loss probability under two bounds, respectively maximum coding opportunity and minimum coding opportunity. © 2015 IEEE.


Li W.,Hubei University | Li W.,Wuhan Research Institute of Post and Telecommunications | Xu Z.-Q.,Hubei Engineering University | Yang Z.,Wuhan Research Institute of Post and Telecommunications
Communications in Computer and Information Science | Year: 2012

Peer participation in P2P systems is inherently dynamic and must be taken into account in both the design and evaluation of any large scale DHT network. P2P network needs to deal with the current churn to provide high availability and quality of service especially, for example, in the mobile environments. Previous study can not provide a method to obtain the churn status in real-time. Thus they can not propose a valuable reference to resolve current churn problems. In this paper, we transfer the information of Churn status into the lookup delay time by lookup delay model. Thus we can measure the churn status of the network by lookups of the network. A general method to get lookup information was provided. At last, we evaluate the factors which will affect the efficiency of the measurement by simulations. © 2012 Springer-Verlag Berlin Heidelberg.


Zhu G.,Huazhong University of Science and Technology | Zhu G.,Wuhan Research Institute of Post and Telecommunications | Yu S.,Wuhan Research Institute of Post and Telecommunications | Xu N.,Huazhong University of Science and Technology | Xu N.,Wuhan Research Institute of Post and Telecommunications
Jisuanji Yanjiu yu Fazhan/Computer Research and Development | Year: 2012

The current IP address cache or IP prefix cache technologies have limitations. We analyse the overlapping relationships among prefixes in the global routing tables and propose a threshold-based routing cache method which combines IP address cache and prefix cache technologies without the need of prefix expansion. The threshold value K is selected according to the prefix overlapping features of global routing tables, which overcomes the shortcomings of address caching and prefix caching technologies. Comparison and simulation show that our scheme has better performance over other schemes in cache size, cache hit ratio, fairness among prefixes and incremental prefix updates. For a global routing table with more than 260000 entries and cache size of 30000, above 97% prefix nodes could be 1:1 cached by prefix cache and the other prefix nodes could be cached by address cache with threshold K=4. Computation results show that high-speed forwording could be fulfilled with small cache size.


Qi N.,Oregon State University | Xiao X.,Wuhan Research Institute of Post and Telecommunications | Hu S.,Fudan University | Li M.,Wuhan Research Institute of Post and Telecommunications | And 4 more authors.
2016 Optical Fiber Communications Conference and Exhibition, OFC 2016 | Year: 2016

A reconfigurable 4-channel 32Gb/s NRZ, or 2×25GBaud/s PAM4 Si-Photonic transmitter is designed entirely in CMOS, consisting of a CMOS driver wire-bonded to MZ modulators. Measurement results demonstrate optical eye diagrams with > 5dB extinction ratio and <11pJ/bit power efficiency. © 2016 OSA.


Qu J.-X.,Wuhan Research Institute of Post and Telecommunications | Zhang J.-S.,Wuhan Research Institute of Post and Telecommunications
Wuhan Ligong Daxue Xuebao/Journal of Wuhan University of Technology | Year: 2011

The system architecture of home gateway was described which used Linux operating system as development environment and under microprocessor without interlocked piped stages 32-bit embedded micro control unit. By migrating embedded Linux operating system, developed the appropriate drivers, applications and management interface on this basis, combined with wireless communication technology to achieve home gateway. The home gateway had uplink interfaces supported asymmetric digital subscriber line, passive optical network, Ethernet over coax and other access methods, also provided downstream interfaces such as voice over internet protocol, internet protocol television, personal computer, universal serial BUS, universal asynchronous receiver/transmitter and wireless fidelity wireless signal. The home gateway could exchange information, configure, update and remote control flexibly via world wide web browser, simple network management protocol, and command line interface means.


Zhu W.,Wuhan Research Institute of Post and Telecommunications
2nd International Conference on Future Networks, ICFN 2010 | Year: 2010

This paper first presents a brief overview of the PBB and the H-VPLS technologies, along with the shortcomings of existing H-VPLS, and then designs the solutions by deploying PBB interoperating with H-VPLS over networks with a MPLS core, which improve the standard H-VPLS. © 2010 IEEE.

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