Aim To design multiuser quantum signaling network for the purpose of interworking with traditional communication network.Methods A multiuser quantum signaling network with multi-stages hierarchy level network topology is proposed and a quantum signaling system is introduced.Multi-classes quantum signaling transmission is based on quantum teleportation and entanglement swapping.Results SBER(Signaling Bit Error Rate) decreases with higher quantum channel coefficient or lower base angle offset,the transmission damage is mainly due to the quantum noise in the condition of base angle offset is below 6 degree,the relay mechanism can achieve higher reliability by decreasing SBER(Signaling Bit Error Rate).Conclusion The network has plain structure,high expandability,robust reliability.The mechanism of return route and relay can reduce the interference of quantum channel.
Aim To design multiuser quantum signaling network for the purpose of interworking with traditional communication network.Methods A multiuser quantum signaling network with multi-stages hierarchy level network topology is proposed and a quantum signaling system is introduced.Multi-classes quantum signaling transmission is based on quantum teleportation and entanglement swapping.Results SBER(Signaling Bit Error Rate) decreases with higher quantum channel coefficient or lower base angle offset,the transmission damage is mainly due to the quantum noise in the condition of base angle offset is below 6 degree,the relay mechanism can achieve higher reliability by decreasing SBER(Signaling Bit Error Rate).Conclusion The network has plain structure,high expandability,robust reliability.The mechanism of return route and relay can reduce the interference of quantum channel.
A quantum signaling transmission scheme based on quantum entanglement,local unitary operation and teleportation is proposed for signaling transmission in a multiuser quantum signaling network with multi-stage hierarchy level network topology.The analytical result shows that the scheme is secure in case of eavesdropping attack including intercept-measure-resend attacks,intercept-replace and adding-ancilla attacks.Consequently,the probability model of quantum signaling transmission damage probability and the repair strategy of the damage of quantum signaling are presented,and the probability model in noise background and non-ideal traditional channel has very low complexity.
Quantum entanglement swapping can be used to establish reliable quantum remote transmission channel so as to realize transmission of quantum states. However, the highly stable quantum network is required in the quantum channels when using quantum entanglement swapping, otherwise it will waste a lot of entanglement resources. In order to save entanglement resources, we have to put forward a kind of quantum communication network transmission protocol based on packet switching, according to the theory of quantum teleportation. Firstly, the principle of packet switching in computer network is introduced. Next we describe the implementation process of quantum network transmission protocols which are based on entanglement swapping and packet switching. We then analyze the reliability, security and utilization rate of entanglement of the protocol we have proposed. And after that the quantitative relationship about the number of entanglement quantum states, the number of routers and link error rates are calculated. Finally, we compare these two transmission protocols. Simulation results show that the number of entanglement for these two protocols is equal without consideration of the link errors. When taking them into account, the packet switching transmission protocol can save numbers of entanglement resources obviously. In addition, with the increase of number of routers and the rise in link error rates, the quantum communication network transmission protocol based on packet switching will need less entanglement resources than that based on entanglement swapping. Therefore, when the quantum transmission network is not stable, the packet switching transmission protocol has a better transmission performance, and it can be applied to the future construction of quantum network.
Aiming at the quantum signalling repeater network model for multi-user,environment quantum noises effect on remote transmission of signalling was studied.A kind of quantum signaling repeater strategy was purposed after the theory of quantum swapping being analyzed.Then a bus network model was put forward and the success rate of long distance quantum signaling transmission was simulated.The results show that long distance signaling transmission has a close relationship with the noise power spectral density,transmission distance and repeater times.When noise power spectral density is constant and there is no repeater during the transmission process,the success rate declines like plesio-flat-parabola with increasing of the transmission distance.On the condition of constant noise power spectral density and constant transmission distance,the success rate increases obviously while the repeater times is increasing.Therefore,on the behalf of reliable quantum signaling transmission the transmission distance and repeater times should be designed properly under the circumstance of constant background noise.
This paper puts forward a quantum signaling switch model. The quantum signaling switch consists of a classical information control module, an exchange control module and a quantum exchange module. Classical control module transmits the initial entangled state information to the entanglement measurement and switching unit and updates the routing information. Exchange control module will choose the path, and is ready for the distribution channel of the entanglement photons. The quantum exchange module generates quantum entanglement pairs, measures the Bell state and achieves entanglement swapping. Quantum signaling switches can realize multi-user communication and local area network communication. Through the performance analysis and simulation of the switch, the results show that the switch is simple in structure, secure and easy to expand; also the time delay is small. This will be helpful for the construction of the quantum communication network.
The optimal relay path calculation and selection are important factors to affect the performance of quantum communication network. Current researches seldom consider the quantum path selection in real noisy environments. One of the difficult problems is how to analyze the influence of the noise on the quantum communication in multi-hop channels. This paper aims to solve the path selection problem of the quantum teleportation network in noisy environments. The process of entanglement swapping in the phase damping channel is first studied with an example of two-hop quantum channel, whose damping factors are p1 and p2. The entanglement states |φ> 12+ and |φ> 34+ are distributed separately in each hop. After the entanglement swapping, the density matrix of the entanglement state of photon 1 and photon 4 is obtained by performing a partial trace over the environment. Then, the Bures fidelity of this entanglement is calculated. After that, we define the path equivalent damping factor to describe the characteristic of the two-hop noisy quantum relay path. With an equivalent calculation method, the results above can be generalized to multi-hop channel. The path equivalent damping factor of the multi-hop amplitude damping channel is also obtained. According to these results, we propose an optimal relay protocol for the quantum teleportation network with the criterion of path equivalent damping factor, which means that a relay path with the minimum path equivalent damping factor can obtain the highest teleportation fidelity. The types and parameters of the messages used in the protocol are given. The processes of the relay protocol are described specifically, including neighbor finding, quantum link noise measurement, and quantum link status transmission. An improved Dijkstra algorithm is used in the optimal path calculation. Furthermore, because the entanglement resources maintained in the quantum nodes are limited and may be exhausted in superior quantum links, we propose a resource reservation method to avoid the failure of the relay path setup. Theoretical analysis and simulation show that our method can obtain a lower average equivalent damping factor and higher teleportation fidelity. It can also be seen that increasing the number of the entanglement resources will raise the performance of the quantum network, however, it brings higher cost and complexity. Therefore, the entanglement resources maintained in the quantum nodes must be configured reasonably according to the network scale, the cost, the time delay and the need of the users.
In order to solve the damage problem during remote transmission of quantum signaling, a repeater model of signaling quantum is proposed. In this model, firstly purifying and distributing entanglement of the received signaling quantum state is carried out, to establish entangled channels between the signed sending and receiving. Secondly, through quantum entanglement swapping the quantum signaling is transmitted, for completing the quantum signaling relay. Simulation results show that the success rate of signaling relay can reach more than 97% under the condition that the fidelity is 0.98 and the entangled pairs successful establishing rate is 0.98; the throughput of quantum signaling relay is up to 183kbps when the probability of entanglement swapping, purification, and entangled pairs successful establishing is 0.98.