A medium access control protocol based on quantum entanglement has been introduced by Berces and Imre (2006) and Van Meter (2012). This protocol entirely avoids collisions. It is assumed that the network consists of one access point and two client stations. We extend this scheme to a network with an arbitrary number of client stations. We propose three approaches, namely, the qubit distribution, transmit first election and temporal ordering protocols. The qubit distribution protocol leverages the concepts of Bell-EPR pair or W state triad. It works for networks of up to four CSs. With up to three CSs, there is no probability of collision. In a four-CS network, there is a low probability of collision. The transmit first election protocol and temporal ordering protocols work for a network with any number of CSs. The transmit first election builds upon the concept of W state of size corresponding to the number of client stations. It is fair and collision free. The temporal ordering protocol employs the concepts of Lehmer code and quantum oracle. It is collision free, has a normalized throughput of 100 and achieves quasi-fairness
Our protocols leverage quantum computing and quantum communications. have achieved free-space transmission of an entangled qubit over a record distance of 144 km @cite_17 . Berces and Imre @cite_11 and Arizmend @cite_3 have explored medium access control protocols building upon the concept of quantum entanglement. In a multi hop wireless network, forwarding a quantum state is an important issue. The use of teleportation has been suggested @cite_5 . Assuming that two parties pre share one part each of a Bell pair, the state of a qubit can be transferred from one location to another using two classical bits. Hence, teleportation has the ability to transfer a quantum state over a classical communication channel, e.g., using electromagnetic waves. Because pre-shared entanglement is required between the parties, long-term storage of qubits is needed by the participants. @cite_10 , @cite_0 and @cite_12 have developed wireless network protocols for hop-by-hop @cite_8 teleportation of qubits. Li and Yang @cite_6 use entanglement swapping @cite_15 in wireless sensor networks to achieve confidentiality.
@cite_8 @cite_17 @cite_3 @cite_6 @cite_0 @cite_5 @cite_15 @cite_10 @cite_12 @cite_11
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In quantum communication via noisy channels, the error probability scales exponentially with the length of the channel. We present a scheme of a quantum repeater that overcomes this limitation. The central idea is to connect a string of (imperfect) entangled pairs of particles by using a novel nested purification protocol, thereby creating a single distant pair of high fidelity. Our scheme tolerates general errors on the percent level, it works with a polynomial overhead in time and a logarithmic overhead in the number of particles that need to be controlled locally. Quantum entanglement is the main resource to endow the field of quantum information processing with powers that exceed those of classical communication and computation. In view of applications such as quantum cryptography or quantum teleportation, extension of quantum-entanglement-based protocols to global distances is of considerable practical interest. Here we experimentally demonstrate entanglement-based quantum key distribution over 144 km. One photon is measured locally at the Canary Island of La Palma, whereas the other is sent over an optical free-space link to Tenerife, where the Optical Ground Station of the European Space Agency acts as the receiver. This exceeds previous free-space experiments by more than an order of magnitude in distance, and is an essential step towards future satellite-based quantum communication and experimental tests on quantum physics in space. In this work, a novel medium access control method for classical and quantum communications purposes is proposed. Quantum communications promise secure ways to send valuable information, therefore quantum-device network and quantum medium access control methods which avoids information loss will be necessary. On the other hand, excessive colliding transmissions in congested situations are a problem for classical wireless communications. Quantum parallelism and quantum multipartite entanglement are exploited to design a MAC sub layer which provides the devices a fair and efficient access to the channel. In the wireless sensor networks (WSNs), sensor nodes may be deployed in the hostile areas. The eavesdropper can intercept the messages in the public channel and the communication between the nodes is easily monitored. Furthermore, any malicious intermediate node can act as a legal receiver to alter the passing messages. Hence, message protection and sensor node identification become important issues in WSN. In this paper, we propose a novel scheme providing unconditional secure communication based on the quantum characteristics, including no-cloning and teleportation. We present a random EPR-pair allocation scheme that is designed to overcome the vulnerability caused by possible compromised nodes. EPR pairs are pre-assigned to sensor nodes randomly and the entangled qubits are used by the nodes with the quantum teleportation scheme to form a secure link. We also show a scheme on how to resist the man-in-the-middle attack. In the framework, the qubits are allocated to each node before deployment and the adversary is unable to create the duplicated nodes. Even if the malicious nodes are added to the network to falsify the messages transmitting in the public channel, the legal nodes can easily detect the fake nodes that have no entangled qubits and verify the counterfeit messages. In addition, we prove that one node sharing EPR pairs with a certain amount of neighbor nodes can teleport information to any node in the sensor network if there are sufficient EPR pairs in the qubits pool. The proposal shows that the distributed quantum wireless sensor network gains better security than classical wireless sensor network and centralized quantum wireless network. In distributed wireless quantum communication networks, because of the storage of the clients, the EPR pairs are important resources. The lack of EPR pairs limits the size of networks. Besides, to accomplish quantum teleportation, both classical and quantum information need to be transmitted. We may have difficulty in building classical and quantum channels at the same time. To solve these problems, we introduce mesh structure into wireless quantum communication. The distributed wireless quantum networks can be improved by this mesh structure we proposed. Moreover, a quantum routing protocol based on quantum relay mechanism is proposed in this mesh structure. An unknown quantum state 〉 can be disassembled into, then later reconstructed from, purely classical information and purely nonclassical Einstein-Podolsky-Rosen (EPR) correlations. To do so the sender, Alice,'' and the receiver, Bob,'' must prearrange the sharing of an EPR-correlated pair of particles. Alice makes a joint measurement on her EPR particle and the unknown quantum system, and sends Bob the classical result of this measurement. Knowing this, Bob can convert the state of his EPR particle into an exact replica of the unknown state 〉 which Alice destroyed. Using independent sources one can realize an «event-ready» Bell-Einstein-Podolsky-Rosen experiment in which one can measure directly the probabilities of the various outcomes including nondetection of both particles. Our propasal involves two parametric down-converters. Subcoherence-time monitoring of the idlers provides a noninteractive quantum measurement entangling and preselecting the independent signals without touching them. We give the conditions for high fringe visibility and particle collection efficiency as required for a Bell test In this paper, a quantum routing mechanism is proposed to teleport a quantum state from one quantum device to another wirelessly even though these two devices do not share EPR pairs mutually. This results in the proposed quantum routing mechanism that can be used to construct the quantum wireless networks. In terms of time complexity, the proposed mechanism transports a quantum bit in time almost the same as the quantum teleportation does regardless of the number of hops between the source and destination. From this point of view, the quantum routing mechanism is close to optimal in data transmission time. In addition, in order to realize the wireless communication in the quantum domain, a hierarchical network architecture and its corresponding communication protocol are developed. Based on these network components, a scalable quantum wireless communication can be achieved. Medium Access Control (MAC) is an important part of wireless telecommunication systems. The main goal of a MAC protocol is to provide the best usage of the common resources for the users. One of these resources is typically the communication channel. By quantum informatics and computation - that gain more and more attention - some calculations and algorithms may become more efficient. The possible implementation of a quantum based system would lead us to great benefits, by applying it to an already existing problem. Here we give a model for medium access control via quantum methods.