58 lines
1.9 KiB
Plaintext
58 lines
1.9 KiB
Plaintext
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== OsmoBTS PHY interface abstraction
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The OsmoBTS PHY interface serves as an abstraction layer between given
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PHY hardware and the actual logical transceivers (TRXs) of a BTS inside
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the OsmoBTS code base.
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=== PHY link
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A PHY link is a physical connection / link towards a given PHY. This
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might be, for example,
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* a set of file descriptors to device nodes in the /dev/ directory
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(sysmobts, litecell15)
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* a packet socket for sending raw Ethernet frames to an OCTPHY
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* a set of UDP sockets for interacting with OsmoTRX
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Each PHY interface has a set of attribute/parameters and a list of 1 to
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n PHY instances.
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PHY links are numbered 0..n globally inside OsmoBTS.
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Each PHY link is configured via the VTY using its individual top-level
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vty node. Given the different bts-model / phy specific properties, the
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VTY configuration options (if any) of the PHY instance differ between
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BTS models.
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The PHY links and instances must be configured above the BTS/TRX nodes
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in the configuration file. If the file is saved via the VTY, the code
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automatically ensures this.
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=== PHY instance
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A PHY instance is an instance of a PHY, accessed via a PHY link.
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In the case of osmo-bts-sysmo and osmo-bts-trx, there is only one
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instance in every PHY link. This is due to the fact that the API inside
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that PHY link does not permit for distinguishing multiple different
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logical TRXs.
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Other PHY implementations like the OCTPHY however do support addressing
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multiple PHY instances via a single PHY link.
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PHY instances are numbered 0..n inside each PHY link.
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Each PHY instance is configured via the VTY as a separate node beneath each
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PHY link. Given the different bts-model / phy specific properties, the
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VTY configuration options (if any) of the PHY instance differ between
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BTS models.
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=== Mapping PHY instances to TRXs
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Each TRX node in the VTY must use the 'phy N instance M' command in
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order to specify which PHY instance is allocated to this specific TRX.
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