###### tags: `報告`

# ara::nm 3: Partial Network

Documents (R22-11):
[SWS_NetworkManagement](https://www.autosar.org/fileadmin/standards/adaptive/22-11/AUTOSAR_SWS_NetworkManagement.pdf)
[PRS_NetworkManagementProtocol](https://www.autosar.org/fileadmin/standards/foundation/22-11/AUTOSAR_PRS_NetworkManagementProtocol.pdf)
[EXP_LayeredSoftwareArchitecture(Classic Platform)](https://www.autosar.org/fileadmin/standards/classic/22-11/AUTOSAR_EXP_LayeredSoftwareArchitecture.pdf)

## What's new in R22-11?

- "PN Information" changed to "PNC Bit Vector" (only name change).

## Definition of Partial Network

Partial Network(PN) is a method to *only* connect the nodes that are needed to do certain things, just like subnet. The reason doing this is to make the vehicle more efficient. This is an optional feature in adaptiveNM because if it is not implemented, the node will simply call all the nodes(in NMCluster? or other things that have not discovered), which will not generate any error.

## PN Cluster

Group of nodes connected by Partial Network is called PN Cluster.

Note that PN Cluster is different from NM Cluster.
This is an example in CAN.
(Note that PN only supports CAN&FlexRay in Classic Platform)

## CBV, PNI, PNSR

We skipped the content of PNI and PNSR before when we talked about CBV.

PNI(Partial Network Information Bit) is an indicator that are there PN Bit Vector in following message. If PNI is `0`, we simply skip everything about Partial Network.

If PNI is `1`, it indicates there will be PNC Bit Vector in the NM Message at the byte `pncVectorOffset` and length of `pncVectorLength`(in bytes).

> 簡單來說，PNI是代表這次的NM Message中是否有關PartialNetwork的內容。

when PNSR(Partial Network Shutdown Request) is 1, involved PN Clusters will be shutted down. PNSR shall be issued by top-level PNC Coordinator.

> PNSR代表這次的NM訊息中有沒有要求PN休眠的訊號。(這個訊號只能由Top-level PNC Coordinator發出)

Note that PNC Coordinator is different from NM Coordinator(which is not available in adaptive NM).

## PNC Bit Vector

Every PN has a unique bit location in PNC Bit Vector, named `PNC Bit`.

If PNI=0, Nm Message should not have PNC Bit Vector.

> PNI=0, 不算

If PNI=1 and PNSR=0, PN is requested if the PN's PNC Bit is 1.

> PNI=1 and PNSR=0, 若PNCBit=1則啟動，若PNCBit=0則釋放(release)

If PNI=1 and PNSR=1, All the Partial Network were the corresponding PNC bits in the PNC Bit Vector are set to 1 are indicated to be released(0). This should be performed by intermediate PNC coordinator. It will be an error if top-level PNC coordinator recieves it, and it should be treated as `PNSR=0` when PNC leaf node recieved it.

> 當兩者皆為1的時候，intermediate coord.會先接收到，並且開始將自己所管轄的leaf nodes關閉(傳送request bit為0的訊息給他們)。

It looks like this when sending shutdown request:

## My thoughts

Partial Network is not actually in Network Management, it's just a protocol(or method?) of network connection. It's actually not "managed" by NM, and NM is just delivering the message.

PN is defined in AUTOSAR Classic Platform, and is controlled in other modules in Classic Platform. There are actually very few documentations on Adaptive Platform than Classic Platform.

I think PN and APNM are very similar, and it is not necessary here in Adaptive. Since there is NM State Machine & NM Cluster to record every connection methods, utilizing subnets, and sleep the ECU, Partial Network is not really in need. It is likely to be a backward-capatible functionality.