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In wind farms, the energy storage system can realize the time and space transfer of energy, alleviate the intermittency of renewable energy and enhance the flexibility of the system. However, the high cost limits its large‐scale application. Cloud energy storage (CES) can provide users with leasing energy storage service at a relatively lower price, and can provide energy trading service. Wind farms can lease CES and participate in energy transaction to reduce the cost of energy storage and suppress wind power fluctuations. This paper proposes a framework of wind farm system based on CES service, and designs a power allocation strategy. Considering whole‐life‐cycle cost of the self‐built energy storage, leasing and trading cost of the CES and penalty cost of wind abandonment and smooth power shortage, an optimal configuration model of combined energy storage capacity in wind farms based on CES service was established to minimize the total annual cost. Taking a wind farm in Germany as a case study, it is verified that the model in this paper can effectively reduce the cost, extend the service life of self‐built energy storage equipment and suppress the wind power fluctuations.

Because the traditional oil level gauge transformer relies on manual regular patrol detection, it is not easy to know the state change of the oil level in real time. In recent years, the rapid development of AR/VR technology, the positioning, and the construction of maps of robots have also received widespread attention, and the oil level inspection task has gradually evolved in the direction of intelligent machine inspection. Based on this background, this paper studies the Cartographer algorithm, according to the mapping results for path planning, to achieve robot autonomous navigation of the designated location. After arriving at the destination, the user obtains the oil level by the depth camera, and uses the YOLOv4 to design an intelligent detection algorithm for oil level detection, using neural networks to learn the oil level state in various weather, and train a dedicated model. Through experimental verification, the inspection robot can complete the construction of the map and realize autonomous path navigation according to the target point, and the oil level detection system based on the YOLOv4 algorithm can achieve an accuracy of more than 90% for the recognition of oil level information, which has good applicability.

There are two problems with fingerprint matching indoor positioning technology based on Bluetooth Low Energy; in the process of collecting Bluetooth signals, due to the shadow effect and multipath effect, the signal is prone to violent fluctuations, abnormal values and special values, and Kalman filtering is commonly used only for Linear systems, for one-dimensional non-linear Bluetooth signals, are prone to data dispersion, causing positioning errors. The commonly used k-means clustering algorithm in the region division stage requires the number of clusters and the value of k to be specified in advance, which is more sensitive to the initial value and cannot determine the number of reference points according to the positioning environment. Based on the above problems, the extended Kalman filter (EKF) optimization database is first proposed. The nonlinear system adopts local Taylor expansion to form a linear system, and the problem of Kalman filter's sensitivity to nonlinear data is solved by the regression iteration method. The multi-dimensional similarity propagation clustering algorithm (MAP) is proposed, and the Pearson correlation coefficient dimension based on RSSI is proposed to redefine the similarity matrix elements. The results show that the fingerprint database of the proposed combination algorithm is optimized, the reference point area is more detailed, the algorithm adaptability is higher, and the average positioning accuracy is improved.

A simulation study on four packet optical integrated networks shows that flows are fully restorable on 41%–94% dual fiber-cut scenarios where single failure restoration is enabled on the packet layer and no protection is available on the optical layer. This ratio increases to 94%-99.7% after the optical layer adds the path protection. This demonstrates the incompetence of simple combination of single failure protections on both layers using existing techniques, and the necessity of protection coordination across layers for full dual failure restorability.

A multi-layer network planning solution is proposed, which performs multi-layer VLAN sub-interface grooming, multi-layer topology design and coordinative protection planning. Numerical results show that our solution achieves 15%~40% CAPEX saving on five IP-Optical real networks.

We study the dynamic burst assembly based on traffic prediction and offset and delay differentiation in optical burst switching network. To improve existing burst assembly mechanism and build an adaptive flexible optical burst switching network, an approach called quality of service (QoS) based adaptive dynamic assembly (QADA) is proposed in this paper. QADA method takes into account current arrival traffic in prediction time adequately and performs adaptive dynamic assembly in limited burst assembly time (BAT) range. By the simulation of burst length error, the QADA method is proved better than the existing method and can achieve the small enough predictive error for real scenarios. Then the different dynamic ranges of BAT for four traffic classes are introduced to make delay differentiation. According to the limitation of BAT range, the burst assembly is classified into one-dimension limit and two-dimension limit. We draw a comparison between one-dimension and two-dimension limit with different prediction time under QoS based offset time and find that the one-dimensional approach offers better network performance, while the two-dimensional approach provides strict inter-class differentiation. Furthermore, the final simulation results in our network condition show that QADA can execute adaptive flexible burst assembly with dynamic BAT and achieve a latency reduction, delay fairness, and offset time QoS guarantee for different traffic classes.

A cost efficient multi-phase algorithm is proposed to achieve 5-15% overall cost reduction and a better cost distribution on capital investment among various phases comparing to the green-field or incremental network planning algorithms on OTN networks.

Based on traffic prediction, a new reservation method is proposed to reduce delay and void filling ratio at edge node of optical burst switching networks. Simulation studies show that our method achieves an important improvement and has a dynamic optimum weight value in a certain offset time.

A diverse routing algorithm is introduced to maximize dual fiber-cut protection on bi-connected networks, where each flow have to use two or more partially disjoint backup paths to protect all restorable dual failures.

Hierarchical (multi-core) Wavelength Division Multiplexing (WDM) networks present a challenging design problem to the network designer who wishes to establish all-optical circuits end-to-end and across multiple network cores. Due to the nature of the hierarchical structure and its traffi distribution, it is likely that the inner core requires more capacity when compared to the capacity required by the metro cores, which are individually connected to the inner core. This capacity mismatch cannot be addressed by assigning distinct transmission rates to each core, as this solution would result in using electronic time division add-drop multiplexer to interconnect the traffi across cores with distinct rates. An alternative solution to addressing the capacity mismatch between WDM metro and inner core is explored in this paper, which is based on a limited number of wavelengths (a subset of the full set) being used in the metro core, when compared to the full set of wavelengths being used in the inner core. Two available architectures are presented in the paper, discussing their respective advantages and disadvantages.

This paper investigates the traffic properties before and after assembly in edge node of Ethernet over optical burst switching (OBS) network for the first time. The features of the edge access system are that (i) Forty Ethernet sources aggregate into optical burst edge node. Moreover they all generate self-similar traffic and have the same parameters. (ii) The packet size of sources follows Pareto distribution with the range from 64 to 1518 bytes. (iii) Packets are assembled into bursts according to four classes and fifteen output ports. Burst and interarrival time distributions are simulated under time-based and length-based assemble schemes. Self-similar traffic Hurst parameter is compared through R/S and V/T plot. Finally three self-similar traffic generating methods are given. Simulation results demonstrate that, multi-source traffic increases self-similar degree, however after assembly, time-assembly scheme can decrease self-similar degree, and aggregated burst size is close to Gaussian distribution. Length-assembly method has no effect on the self-similarity of input traffic. RMD is fit for study of burst network with large self-similarity.

This paper focuses on burst assembly at edge node in optical burst switching networks, which can be implemented to provide the delay QoS guarantee for the whole network. Based on traffic prediction and delay fairness of different classes, a Prediction and delay QoS Burst Assembly (PQBA) mechanism is proposed to reduce the assembly delay and improve the delay fairness especially for high priority service at edge node. We compare the delay, burst size, burst utilization and length error rate of all service classes under different offered load. Simulation studies are carried out for PQBA and the results show that high priority service with relative small burst size achieves a low assembly delay and high burst utilization. Consequently, PQBA realizes the QoS-based delay fairness and service class differentiation at edge node.

A multi-wavelength optical label switching test-bed is introduced. The optical label is constructed by a series of optical pulses with different wavelengths that are in the same WDM optical channel. High speed optical switches and DSP chips are used to process the optical label signal. The four-node programmable optical label switching network is demonstrated by transmitting PC capture signal and multimedia video flow with standard Gigabit Ethernet frame. Furthermore, an optical packet assembly and segmentation method is proposed for Gigabit Ethernet Optical Label Switching networks. Two timers are used to realize the exact timing on microsecond magnitude between optical label and programmable optical Ethernet packet. The experimental system executes the real time process and the Gigabit Ethernet data packets with optical label are switching and transmitting successfully. The optical packet programmable method enhances bandwidth utilization and throughput, increases the intelligence, flexibility and multi-service bearing ability of the Optical Label Switching network.

Traditional burst assembly method only differ service class priority by increasing extra offset time so as to assure QoS at Optical Burst Switching (OBS) core node which increases all network delay extremely, especially for optical network with many hops and large radius. In order to take full advantage of flexible buffer and control function of electronics device and optical large capacity predominance, it is desired to process real-time traffic at edge ingress node and guarantee delay fairness under small enough delay and QoS based on offset time differentiation for various classes. To achieve lower assembly delay at OBS edge node and offset time based QoS guarantee at core node, this paper proposes an approach called Prediction and Offset QoS Assembly (POQA) to improve existing burst assembly mechanism at edge node. POQA method takes into account the delay fairness and QoS-based offset time adequately. The ratios of assembly time and offset time are introduced to make a delay and offset differentiation among various traffic classes. Assembly delay, burst size, burst utilization and length error of various classes are compared under different offered load. Moreover, in contrast with traditional time assembly method, simulation results show that POQA method can achieve a significant improvement in terms of burst delay and utilization and realize the delay fairness and offset time QoS differentiation under different traffic offered load.

The current edge assembly granularity preserved beforehand in optical burst switched (OBS) networks lacks flexibility to actual network traffic and increases assembly overhead and delay. Offset time generating mechanism after traffic shaping increase network delay and cut down its robustness. Consequently, it is significant to present an effective dynamic burstification scheme to process real-time traffic, reduce assembly delay and provide QoS guarantee for different priority traffic at edge node. This paper focuses on dynamic burst assembly at edge node in optical burst switching networks, which can be implemented to improve the performance of the whole network. Based on traffic prediction, a new dynamic adaptive assembly mechanism on load estimate, termed Dynamic Adaptive Assembly (DAA), is proposed to reduce assembly delay, estimate real-time network traffic character and dynamically adjust Burst Assembly Time (BAT) at edge node. The dynamic range of BAT for four traffic classes is introduced to make compare among current and previous prediction with different prediction time under QoS based offset time. We investigate the influence of current and previous offered load with different prediction time and offset time. Simulation studies are carried out for various traffic classes. The results show that DAA can achieve little delay and provide adaptivity, flexibility and delay fairness for burst assembly.

A kind of optical coarse packet switching based on optical label routing is intrduced. In the switching, the swapping granularity is coarse compared to common optical packet switching, and the header of optical packet is labeled by multi-wavelengths. Some realization techniques on core switching node and edge node with terminator are studied. A principle experiment system is established to perform the optical coarse packet transmitting, switching, and receiving, and verify the feasibility of such optical coarse packet switching.

The rapid increase of IP service and large capacity in DWDM layer request the all-optical packet delineation and process. Optical burst switching is a promising technology in the future IP/DWDM networks, which provide a feasibility to realize the optical packet switching without optical buffer. Presently the QoS guarantee of OBS depends on the bandwidth control protocol. JET based on RFD generally applied in OBS network is considered in this letter. According to the queuing theoretical model, the performance of one node is studied using simulations. Besides the traditional exponential arriving and service traffic, we analysis the general and self-similar traffic under the same average service time. The analysis and simulating results for different class have important effects on networking performance by comparing the queuing service models.

We introduce an intelligent optical cross connect OXC structure based on our lambda-group model, as well as a dynamic algorithm of configuration helpful to compli- cated optical traffic grooming, which presents a distinctive approach of dividing granularities into specific tunnels for ef- fective treatment. Results and figures from experiments show that the particular channel partition not only is helpful to port reduction significantly, but also improves the channel and blocking performance for dynamic connection requests. © 2006 Society of Photo-Optical Instrumentation Engineers.

Hierarchical (multi-core) Wavelength Division Multiplexing (WDM) networks present a challenging design problem to the network designer who wishes to establish all-optical circuits end-to-end and across multiple network cores. Due to the nature of the hierarchical structure and its traffi distribution, it is likely that the inner core requires more capacity when compared to the capacity required by the metro cores, which are individually connected to the inner core. This capacity mismatch cannot be addressed by assigning distinct transmission rates to each core, as this solution would result in using electronic time division add-drop multiplexer to interconnect the traffi across cores with distinct rates. An alternative solution to addressing the capacity mismatch between WDM metro and inner core is explored in this paper, which is based on a limited number of wavelengths (a subset of the full set) being used in the metro core, when compared to the full set of wavelengths being used in the inner core. Two available architectures are presented in the paper, discussing their respective advantages and disadvantages.