[Qirg] draft-wang-qirg-quantum-internet-use-cases-04; MVDB03

[VAN DEN BOSSCHE Mathias <[e-mail]>]

Doc: draft-wang-qirg-quantum-internet-use-cases-04

ID : MVDB 03

Page/section: pp 5-6/ § 4.3

Proposal/Question:

It looks like the definition of network planes is a bit confusing.
Moreover the descritpion of the management plane is missing.
I propose below first set of inputs regarding the way the planes could be described.
BTW, this is more for an architecture document than for a use case document.

Explanation:

Whereas the OSI protocol stack layers are probably of little help, the broader concepts of network planes are likely to be helpful. The usual distinction
between network planes is

- User/data plane: data traffic generation & forwarding
- Control plane : establish connection, authenticate users, enforce QoS policy
- Management plane : defines the rules to be applied by the control plane

Let us see how this maps on a QIN.

First, there are two high level functionalities (call them e.g. "macrofunctions")
* end-to-end physical link set-up functionality to create entanglement between the targeted end nodes
* functionality to send the q-info among entangled end nodes
Probably each deserves its own protocol stack. The latter is probably simple as it involves less elements.

Then, inspecting each macrofunction, one finds

* The end-to-end physical link set-up involves the following steps
  - the physical establishment of segment entanglement, that requires
    . physical entangled system (e.g. photon pairs) distribution
    . heralding(*) of the entangled system availability
    . distillation and storage of fewer, more entangled systems
  - the swapping/routing of entanglement from segment to segment that requires
    . identifying which neighbouring node are to be connected
      (routing table? centralised f° of resource?)
    . Bell-state measurement at the common node
    . Transmission(*) of BSM results to neighbouring nodes
    . unitary transformation to lift ambiguity at the routed node

* The transmission of the q-information involves
  - the above set-up of entanglement among end nodes
  - Bell-state measurement at the sender node
  - Transmission of BSM to the receiver node(*)
  - unitary transformation to lift ambiguity at the routed node

(*) this implies a classical network with its own stack that is taken for granted

Trying to abstract this into functions and planes, the result could be

User plane with the functions
* The BSM of the qbit to be transmitted & entangled-channel local part
* The creation of elementary entanglement resource between each pair of contiguous nodes
* The weaving(**) of entanglement though contiguous links by swapping
* The auxiliary classical network to transfer the BSM results
* The unitary transformation on the received qbit entangled-channel remote part to lift its ambiguity

Control plane with
* The authentication of end nodes
* The establishment of the auxiliary channel to transfer the heralding data
* The establishment of a quantum communication session between 2 authenticated end nodes
* The monitoring of the network resource level (fidelity and number of available entangled parts)
* The definition of the paths along which to weave(**) the end-to-end entanglement

Management plane with
* The rules to determine the paths along which to weave(**) the end-to-end entanglement
* The rules to prioritise the creation of entanglement resource among the network
* The set of acceptable KPI values of the network.

(**) I prefer weaving because routing carries the meaning of something that is pushed while what entanglement set-up does is more a spider-like work.

Discussion:

TBD

Decision:

TBD

[@@ THALES ALENIA SPACE INTERNAL @@]