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A set of IEEE standards that aim at providing time-synchronized
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low-latency streaming services through IEEE 802 networks. The currently
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in use AVB technology is called *Gen1* and consists of the following
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IEEE standards (or standard amendments): 802.1AS, 802.1Qat, 802.1Qav and
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802.1BA. However, ever increasing need and requirement for low-latency
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time-synchronized communication resulted in on-going works on *Gen2* of
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AVB. The requirements for *Gen2* are no longer shaped only by
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audio-video industry but also by others (e.g. automotive).
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It seems that AVB *Gen2* and White Rabbit have some commonalties and
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these are investigated below. Firstly, the main features of AVB *Gen1*
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are described briefly. Then the requirements, plans and features of AVB
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*Gen2* are described.
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in use AVB technology is called (here) *Gen1* and consists of the
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following IEEE standards (or standard amendments): 802.1AS, 802.1Qat,
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802.1Qav and 802.1BA. However, ever increasing need and requirement for
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low-latency time-synchronized communication resulted in on-going works
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on *Gen2* of AVB. The requirements for *Gen2* are no longer shaped only
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by audio-video industry but also by others (e.g. automotive).
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It seems that AVB *Gen2* and White Rabbit have some commonalties. This
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page is meant to compare next generation of Audio Video Bridging (AVBg2,
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or AVB Gen2) with White Rabbit, both in terms of requirements and
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proposed solutions. Firstly, short introduction to the current AVB (Gen
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1) is provided. Then requirements and proposed solutions for AVBg2 are
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summarized. In a similar form to AVB and AVBg2 descriptions, WR
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description is provided. Finally, AVBg2 and WR are compared. The
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comparison is based on the author's view of AVB and AVBg2 described
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below (which is not thorough).
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## **AVB *Gen1***
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... | ... | @@ -446,3 +452,12 @@ not acceptable by the most stringent AVBg2 requirements), however: |
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The idea of Time Aware Shaper (both at end stations and WR switches) is
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worth considering for WR, especially to meet GSI's requirements.
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Some points (additional requirements) that would need to be considered
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to use AVBg2 instead of WR:
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- syncE + asymmetry so that sub-nanosecond synchronization could be
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achieved
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- "broadcast stream" - it is not clear whether AVBg2 could handle a
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stream to most of the end stations in the network (~2000) and
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provide (seamless) redundancy
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