... | ... | @@ -396,7 +396,8 @@ In WR, the critical data stream is supposed to be broadcast within VLAN, |
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thus a stream is propagated to all the end stations within a VLAN: a
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particular case of such solution is to define VLAN for a stream between
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two end stations. Still, separate VLAN-streams do not have separate
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resources.
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resources. On the other hand, WR critical data one-to-many stream seems
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to be a corner case of AVB stream.
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In WR, the critical data is encoded using Forward Error Correction to
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prevent loss of data critical due to data corruption (bit error
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... | ... | @@ -407,10 +408,18 @@ prevails: |
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- if a network can allow dynamic network reconfiguration (e.g.
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requirement of reconfiguration time \< 100ms, [Toyota,
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page 6](http://www.ieee802.org/1/files/public/docs2011/new-avb-KimNakamura-automotive-network-requirements-0311.pdf)),
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then end applications can accept some data loss. Therefore, the some
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data loss due to data corruption is also acceptable.
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it means that the end applications can accept some data loss.
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Therefore, some data loss due to data corruption is acceptable.
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- if seamless redundancy is required, static network redundancy
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(independent paths) is used.
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(independent paths) is needed.
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WR takes advantage of assumed one-to-many characteristics of the
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critical data in :
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- ultra-fast forwarding: for critical data the forwarding data base
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needs to be verified only against VLAN which is much faster then MAC
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lookup
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- redundancy mechanisms: data is always forwarded everywhere except
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links which create loops
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- no need for sophisticated stream reservation
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Using FEC has a negative effect on the data delivery latency (probably
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not acceptable by the most stringent AVBg2 requirements). However,
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