173 results about "Network emulation" patented technology

An emulator for emulating a wireless network comprised of a plurality of RF nodes is comprised of a programmable controller for emulating the movements of the plurality of RF nodes within an emulated space. The controller provides both information and control signals based on the emulated movements. A programmable logic core receives a plurality of signals from the plurality of RF nodes and emulates signal propagation based on the information from the controller. A plurality of signal generation and conversion cards are interposed between the programmable logic core and the RF nodes. The signal generation and conversion cards are responsive to the control signals. Because of the rules governing abstracts, this abstract should not be used to construe the claims.

Emulating a packet reorder condition in a network includes maintaining a counter variable to count packets sent out since the most recent reordered packet. When a new packet arrives, if the counter variable is less than or equal to zero, a current packet lag value is determined. If the current packet lag value is not equal to zero, the new packet is delayed before being sent out in accordance with the lag value, and the counter is updated with the lag value. Otherwise, the new packet is sent out without delay and the counter is decreased by one. The current packet lag value is computed based on supplied configuration parameters. Delaying the new packet includes applying a latency to the packet, the latency comprising a time cost to transmit the packet multiplied by the current packet lag value.

The presen invention provides a network emulation in manual and automated testing tools. A network emulation system is described herein that allows a software developer to accurately simulate different network characteristics while testing an application, framework, or other software code on a single or multiple computers. The system also provides an ability to record a real network's characteristics and apply those characteristics during a test. The network emulation system integrates a network emulation facility into test tools for both manual and automated tests and allows an application, framework, or other software code to be tested while operating under varying networking conditions such as bandwidth, latency, packet reordering and duplication, disconnection, and so forth. Thus, the network emulation system allows a software developer testing software code to quickly and easily determine how the software code will perform in a variety of real-world networking situations without physically setting up each of those situations.

A network emulation device and method in a terminal of an IEEE 802.16 communication system supporting IPv6 communications based on a Neighbor Discovery (ND) protocol are provided. The terminal includes an IPv6 module for performing an ND mechanism to search for a neighbor terminal or a router, a MAC module for communicating based on the IEE 802.16 standard, and a network emulation module provided between the IPv6 module and the MAC module for analyzing a ND message received from the IPv6 module and discarding the ND message or generating a response message for the ND message according to the message type. The network emulation module converts a broadcast ND message to a unicast message and provides the unicast message to a corresponding network device if network information needed to internally generate the response message is not collected.

The invention discloses a network optimizing method and a network emulation system. The network emulation system comprises a network management unit, a radio network controller (RNC), a base station and an emulation transmission terminal, wherein the network management unit is used for controlling the RNC to start a network emulation test for a specified cell; the RNC is used for starting the network emulation test for the specified cell when receiving a network emulation test starting message transmitted from the network management unit, establishing an uplink wireless link for a base station of the specified cell, and starting measurement control for the base station; the RNC is also used for collecting and storing measurement reports submitted by the base station after the measurement control is started; the base station is used for receiving uplink signals of the emulation transmission terminal under the measurement control of the RNC, and measuring, demodulating and decoding the uplink signals to obtain a measurement report and report the measurement report to the RNC; and the emulation transmission terminal is used for transmitting the uplink signals to the base station of the specified cell. Through the network optimizing method and the network emulation system, the accuracy and efficiency of network optimization can be improved.

The invention discloses a distributed graph coloring link dispatch scheme of a wireless sensor network based on a graph coloring algorithm. According to the scheme, firstly, partial interference information is obtained through packet switching among nodes; secondly, a graph vertex coloring analysis is carried out on a generated localized network conflict graph; thirdly, the conflict-free time slot allocation of a wireless sensor network link is obtained. To improve the coloring success rate, two mechanisms are provided. One mechanism is a broadcast safeguard mechanism for improving the broadcast information delivery rate, and the other mechanism is a conflict processing mechanism for solving the coloring conflict problem. According to the distributed link dispatch scheme, the problems of packet loss, delay and the like caused by multi-hop transmission are solved, and the transmitting energy consumption is reduced. The result of the network simulation shows that the distributed graph coloring link dispatch scheme has the advantages over a conventional link dispatch method on the aspects of energy consumption, the space reusing rate, the packet loss probability and the like.

A system and method for measurement of the performance of a network by simulation, wherein time divergence is addressed by using discrete event simulation time to control and synchronize time advance or time slow down on virtual machines for large-scale hybrid network emulation, particularly where the loss of fidelity could otherwise be substantial. A dynamic time control and synchronization mechanism is implemented in a hypervisor clock control module on each test bed machine, which enables tight control of virtual machine time using time information from the simulation. A simulator state introspection and control module, running alongside the simulator, enables extraction of time information from the simulation and control of simulation time, which is supplied to the virtual machines. This is accomplished with a small footprint and low overhead.

A network troubleshooting framework is described. In an implementation, a method includes detecting a discrepancy in operation of a network by supplying data that describes the network to a network simulation so that the network simulation provides an estimation of network performance. A determination is made as to whether the estimation of network performance differs from observed network performance of the network. A root cause of the discrepancy is diagnosed by injecting one or more of a plurality of faults into the network simulation until the estimation of network performance approximates the observed network performance.

The invention provides a double-engine distribution type peer-to-peer network simulation system architecture which is characterized by mainly comprising a node simulation engine and a network simulation engine. The node simulation engine is mainly used for dispatching a local simulation node and executing a simulation protocol; and the network simulation engine is used for conducting information interaction operation, such as receiving/sending simulation message. Under the architecture, a simulation running structure and a universal support structure of the simulation system are isolated, so that the simulation system has favorable extensibility. Meanwhile, the node simulation engine can utilize a simulation application computer to support P2P simulation in a certain scale and then utilizes the network simulation engine to expand the P2P, so that simulation information can be sent to other simulation application computers or an external true P2P for application in the form of a network data packet, thereby expanding the simulation scale and enhancing the trueness of simulation.

The invention discloses an E1 emulation realization method, which relates to the field of network simulation and comprises the following steps of: performing protocol encapsulation on a direction, and performing serialization processing on received data to generate a real-time transport protocol value; assembling a time division multiplexing (TDM) payload into a frame, forming cache data packets by using the processed data, and finishing a corresponding description table; attaching packet headers to the TDM payload, generating control word information and real-time transport protocol information according to configuration, and performing encapsulation according to a protocol; performing clock domain adaptation on the processed data, finishing Ethernet media access control (MAC) processing, and transmitting Ethernet data by using a media independent interface (MII); performing protocol decapsulation on the direction, receiving and caching the Ethernet data, and finishing MAC layer processing; classifying and identifying the Ethernet data packets, extracting the payload and related control bytes, and counting state information; and performing clock recovery on a processed TDM payload code stream, and externally transmitting the processed TDM payload code stream. The method is relatively lower in cost; updating can be performed; and requirements on the performance of a central processing unit (CPU) are reduced, and clock recovery performance is improved.

The invention relates to a design method and system of an electric power information communication network convergence test platform. The test platform system is mainly divided into a service search two-dimensional table, an electric power communication service generator, a traffic shaper, a network simulator, a communication path switch, a service controller and a service ending analyzer and repeater. Electric power communication services are divided to form the service search two-dimensional table according to the IEC61850 protocol, the IEC60870-5-101 protocol, the IEC60870-5-104 protocol, equipment types and the like; non-electric-power service data streams of electric power services, voice, video and the like are obtained, the input electric power communication service test streams are managed through traffic shaping technologies including admission control, input traffic label identification and the like, the electric power communication service streams are transmitted through the simulative network simulator or the path switch of an actual electric system communication network, labeled test service streams are received by the service ending analyzer, statistics and analysis are performed on the result of performance for bearing electric power communication services under information communication convergence, and the method combines an electric power information communication network and a test platform so as to enhance the accuracy and the practicality of tests.

The invention discloses a network simulation method and system in an SDN scene, and the method comprises the following steps: 1, executing a network simulation instruction according to a user request,and enabling a simulation scheduling management module to mirror the current network topology, tunnel and port flow data; 2, simulating a current network fault by the user through a controller front-end page; 3, the controller performs new path calculation according to the mirrored network information; 4, calculating the load condition of the current port according to the new path condition and the tunnel flow condition; and 5, formulating a network status analysis report for the user according to the load condition obtained in the step 4. According to the technical scheme provided by the invention, the problems of traffic burst, difficulty in prediction and network adjustment in the backbone network at present can be effectively solved, and the influence of possible network changes on services is analyzed through simulation of network element/link faults so that the customer fault risk assessment capability is improved and the network robustness is improved.

The invention relates to an IP address distribution system and method facing a distributed network simulation platform. The method includes: performing IP address range and IP block division; storing the kind circulation queue and free list of IP block use conditions; performing IP address distribution and IP address recycling. The method has the advantages customized IP addresses in examples can be processed, automatic IP address distribution is achieved, and flexibility of the network simulation platform is increased; a given range can be divided reasonably, and IP address resources can be utilized to the maximum extent; the IP addresses of examples can be isolated and executed, and network errors caused by IP address conflicts of different examples when physical network cards cannot be isolated are avoided; the IP address resources are stored in sequence by the kind circulation queue, the free list is used for storing discrete available IP address resources, sequential distribution and discrete distribution are combined, and the like.

The invention provides network energy efficiency simulation and evaluation methods and apparatuses. According to preset network simulation environmental parameters, a covering lattice vector of each base station of a to-be-simulated network is determined, and according to the covering lattice vector of each base station in the to-be-simulated network, a coverable lattice vector of the to-be-simmulated network is obtained; simulation parameters are set, and the simulation parameters at least comprise three simulation periods and the duration of each simulation period, simulation timeslice numbers, user numbers, and business types in need of simulation, and the weight of each business type in each simulation period; and simulation is performed according to the covering lattice vector of each base station and the set simulation parameters, and the average power consumption and the average throughput in each simulation timeslice of each base station can be obtained. According to the methods and the apparatuses, the problem that in the prior art, the dynamic energy efficiency of a mobile network cannot be simulated is solved.

The embodiment of the invention discloses a firewall security policy opening method and device based on simulation path analysis. According to the method, quintuple information is obtained by obtaining policy opening application information, then path analysis is carried out in a network simulation environment according to the quintuple information, a path analysis result is obtained, and the network simulation environment is constructed according to connection and mutual access relations of all network devices in an existing network environment. A firewall which prevents access in the path analysis process is positioned as a target firewall according to the path analysis result, a target security policy corresponding to the type of the target firewall is generated according to the targetfirewall, and the target security policy is issued to the target firewall to complete policy opening. Through the method, the firewall for preventing access can be quickly positioned, so that the target security policy corresponding to the target firewall is generated, and the policy opening efficiency is improved.

The invention discloses a multi-node cooperation unmanned aerial vehicle ad hoc network clustering topology reconstruction method. According to the method, firstly, a minimum node ID method is adopted to carry out quick clustering, the weight of each unmanned aerial vehicle node is calculated according to factors such as the speed similarity of nodes in a moving unmanned aerial vehicle ad hoc network, the average distance between the nodes, the average link maintenance time and the unmanned aerial vehicle node residual energy, and cluster maintenance is carried out. Then, on this basis, a method for judging key nodes in a network based on an adjacent matrix in a neighborhood is provided, and whether key nodes in the network fail or not is judged in a distributed mode. Finally, on the basis of the clustering algorithm and the key node judgment method, a two-stage topology repair method is provided for solving the problem that topology damage occurs when the network is attacked by an enemy. A simulation result in a wireless network simulation environment EXata shows that compared with a traditional clustering algorithm, the method can quickly and effectively repair the damaged network topology and improve the throughput of the network.

The invention belongs to the technical field of MIMO communication, and particularly relates to a hybrid precoding algorithm for a partially connected phase shifter network for large-scale MIMO. The algorithm aims to jointly optimize analog domain precoding and digital domain precoding so as to maximize spectral efficiency. The hybrid precoding algorithm is divided into two parts: 1, an analog precoding algorithm; and 2, after an analog precoder is given, obtaining a digital precoder according to a water injection method. The algorithm is suitable for phase shifter networks with different resolutions, including a continuously adjustable phase shifter network, a 1-bit phase shifter network and a 2-bit phase shifter network. A simulation result shows that the difference between the algorithmperformance and the optimal full-digital precoding is about 5dB; and the number of the phase shifters is greatly reduced, so that engineering realization is facilitated.

The invention requests to protect a vertical switching system based on personalized consumption preferences in a heterogeneous wireless network, and provides a vertical switching algorithm based on personalized consumption preferences in order to solve the problem of how to improve user experience on the premise of meeting basic requirements of users in a heterogeneous wireless network environment. Firstly, parameter processing is carried out in a preprocessing module in combination with a current service to obtain network related parameters meeting basic requirements of the service; secondly, a personalized consumption preference weight of the user is obtained through a data mining module of the network side; and finally, a user-defined utility function is constructed in combination with the related parameters and the personalized consumption preference weight, and a target network is selected by comparing the comprehensive utility values of the user to the candidate networks. A simulation result shows that the algorithm enables the user to access the network meeting the personalized consumption preference, reduces the algorithm time overhead and the network congestion rate, and improves the throughput and the user experience.

A hybrid electromagnetic transient simulation method for microgrid real-time simulation, wherein a traditional node analysis method (NAM) and a highly parallel latency insertion method (LIM) are combined, so that the microgrid is firstly divided from a filter of a distributed power generation system to form one latency insertion method (LIM) network containing a power distribution line and a plurality of node analysis method (NAM) networks containing the distributed power generation system respectively, the NAM network being simulated by traditional node analysis method, the LIM network being simulated by the latency insertion method, in an initialization stage, one correlation matrix and four diagonal matrixes containing line parameters used for LIM network simulation being formed according to line topology and parameters of the microgrid, in a main cycle of the simulation, the LIM network solved simultaneously with multiple NAM networks, a parallelism of a microgrid simulation being improved.