Quantum Communication for Wireless Wide-Area Network

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21 Νοε 2013 (πριν από 3 χρόνια και 6 μήνες)

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1

Quantum Communication for
Wireless Wide
-
Area Network

2005
-
0825

2

Outline


Abstract


Introduction


Notations And Preliminaries


Quantum Routing Mechanism


Quantum Wireless Communication
Network


Discussion


Conclusion

3

Quantum Routing Mechanism


Quantum Routing mechanism combines


(1)Quantum Relay (not share EPR
-
pair)


(2)EPR
-
pair Bridging (parallelism)

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Quantum Routing Mechanism
(contd.)


(1)Initial State






(2)Pass CN
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gate(A1
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A2 and C1
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5

Quantum Routing Mechanism
(contd.)


(
3)Pass Hadamard
-
gate(A1 and C1)







(4)Rewrite

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6

Quantum Routing Mechanism
(contd.)


(5)Relation between the measurement outcomes and Bob’s


Qubit state

7

Quantum Routing Mechanism
(contd.)


It can be seen that the proposed quantum routing mechanism is
able to route through more than one intermediate node.


Quantum routing mechanisms as show in below can be
performed in parallelism.


8

Quantum Routing Mechanism
(contd.)


The executing time of the quantum routing mechanism is
approximate to that of the quantum teleportation.



So we conclude that the quantum routing mechanism is close
to optimum in data transmission rate even for the case where
no EPR pair is shared between source and destination.

9

Quantum Wireless
Communication Network


Hierarchical Network Architecture


Quantum Wireless Communication
Protocol

10

Hierarchical Network
Architecture


Components


(1)RTs: Radio Transceivers


(2)LPW: Local Position Warehouse


(3)QBK: Quantum Bridge Keeper


(4)GPW: Global Position Warehouse


(5)EPR Generator

11

Hierarchical Network
Architecture (contd.)


(1)RTs: Which are used to transmit and receive classical data


in the form of electromagnetic.


(2)LPW: Record the information of each wireless quantum


devices that are inside the QBK’s coverage.


(3)QBK: Manage EPR pairs shared with itself and mobile


quantum devices.


(4)GPW: Manage the location information of all mobile quantum


devices. (Update Frequently)


(5)EPR Generator: It is responsible for generating EPR pairs.


12

Quantum Wireless
Communication Protocol


When a wireless quantum device
-
Alice, would like to deliver a


qubit to another wireless quantum device
-
Bob.


(Case1)Bob is inside the coverage of QBK A

Quantum Routing mechanism

Alice

QBK A
→Bob

13

Quantum Wireless
Communication Protocol (contd.)


(Case2)Bob is not inside the coverage of QBK A

Quantum Routing mechanism

Alice

QBK A
→QBK B→Bob

14

Discussion


A
-
EPR pair Supplement


B
-
Routing Path Exploration and Maintenance


C
-
Handover Scheme Modification

15

EPR Pair Supplement


EPR pairs will be consumed each time a quantum routing is
performed. However, due to wireless connectivity, a quantum
mobile device cannot be supplemented with EPR pairs at all
times.


As a result, it might fail to perform the quantum wireless
communication because of using up the EPR pairs.


Therefore, quantum mobile stations require another charging
device to supply EPR pairs.


In other words, EPR pairs just like the traditional battery shall
be considered as a type of precious resource.

16

Routing Path Exploration and
Maintenance


Most of that have been reported routing path schemes are not
suitable for the quantum domain routing.


It is because the traditional schemes prefer to probing the
shortest routing path.


Quantum routing will take the number of remaining EPR pairs
into the consideration.


Example: Two routing paths from mobile device Alice to Bob


(1)Alice
→Candy
3
→Bob


(2)Alice→David
5
→Eric
7
→Bob

17

Handover Scheme Modification


When a wireless quantum device moves into another QBK’s
coverage, it needs to acquire the EPR pairs shared with the
new QBK.
→It can be tackled by utilizing the proposed EPR
-
pair
bridging.

18

Conclusion


This paper proposes a quantum routing mechanism, which
enables a quantum mobile device to teleport a quantum state to
a remote site even if they do not share EPR pairs mutually.


In terms of time complexity, the time that quantum routing
mechanism takes to teleport a quantum states is independent
of the number of routing hops.


From this aspect, the proposed quantum routing mechanism is
close to optimum in data transmission time.


In order to establish a quantum communication infrastructure,
this paper also presents a network architecture and
corresponding communication protocol for wireless WAN.