From 2814fba32901422acd86dd852a7b7770796c5342 Mon Sep 17 00:00:00 2001 From: Harald Welte Date: Fri, 22 Apr 2016 11:39:01 +0200 Subject: add phy_link/phy_instance slides @ osmodevcon --- 2016/osmobts-phy/osmobts-phy.html | 4174 +++++++++++++++++++++++++++++++++++++ 1 file changed, 4174 insertions(+) create mode 100644 2016/osmobts-phy/osmobts-phy.html (limited to '2016/osmobts-phy/osmobts-phy.html') diff --git a/2016/osmobts-phy/osmobts-phy.html b/2016/osmobts-phy/osmobts-phy.html new file mode 100644 index 0000000..a9fbc0b --- /dev/null +++ b/2016/osmobts-phy/osmobts-phy.html @@ -0,0 +1,4174 @@ + + + + +OsmoBTS phy_link / phy_instance + + + + + + + + +
+

Multiple Transceivers in Osmocom

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+
    +
  • + +First OpenBSC supported BTS Siemens BS-11 was 2-TRX + +
      +
    • + +OpenBSC (OsmoNITB) had multi-trx support from the very beginngin + +
      • +
    +
    • +
  • + +ip.access nanoBTS can be stacked for multi-TRX + +
      +
    • + +OpenBSC (OsmoNITB) has supported this for many yeasr + +
      • +
    +
    • +
  • + +Classic OsmoBTS was single-TRX + +
    • +
  • + +osmo-bts-trx was extended with 2 TRX support but not in master + until recently + +
    • +
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OsmoBTS supported hardware (currently)

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+
    +
  • + +osmo-bts-sysmo for sysmoBTS (1002/1020/1100) + +
    • +
  • + +osmo-bts-trx for OsmoTRX (UmTRX, USRP, …) + +
    • +
  • + +osmo-bts-octphy for Octasic OCTDSP / OCTPHY-2G + +
    • +
  • + +osmo-bts-litecell15 for Nuran Litecell 1.5 + +
    • +
+
+
+
+

osmo-bts-sysmo

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+
    +
  • + +osmo-bts-sysmo for sysmoBTS (1002/1020/1100) + +
      +
    • + +shared memory message queues between PHY-DSP and ARM core + +
      • +
    • + +DSP can only implement a single TRX. MultiTRX can be achieved by + stacking like in nanoBTS + +
      • +
    • + +would require one OsmoBTS per sysmoBTS board, each handling one TRX + +
        +
      • + +OML router needed to route OML to different boards + +
        • +
      • + +OsmoBTS would need to be able to run a TRX without BCCH + +
        • +
      +
      • +
    +
    • +
+
+
+
+

osmo-bts-trx

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+
    +
  • + +osmo-bts-trx for OsmoTRX (UmTRX, USRP, …) + +
      +
    • + +had two-trx support in fairwaves branch + +
      • +
    • + +assumes two soft TRXs in a single "transceiver" program (OsmoTRX) + +
      • +
    • + +has lots of global variables assuming a single transceiver program + handling all TRXs :( + +
      • +
    +
    • +
+
+
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+

osmo-bts-litecell

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+
    +
  • + +osmo-bts-litecell15 for Nuran Litecell 1.5 + +
      +
    • + +shared memory message queues between PHY-DSP and ARM core + +
      • +
    • + +very similar to osmo-bts-sysm, but: + +
      • +
    • + +has two TRXs available to ARM CPU + +
      • +
    +
    • +
+
+
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+

osmo-bts-octphy

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+
    +
  • + +osmo-bts-octphy for Octasic OCTDSP / OCTPHY-2G + +
      +
    • + +various different hardware boards (OCBTS3000/3500/4000) with + different number of DSPs and radios + +
      • +
    • + +DSPs interconnected with ARM/x86 CPU over Ethernet + +
      • +
    • + +There can be multiple DSPs, each with two radios and multiiple + software TRX + +
      • +
    • + +most flexible/versatile configuration + +
      • +
    • + +served as the blueprint for phy_link/phy_instance abstraction + +
      • +
    +
    • +
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phy_link / phy_instance

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+osmobts-phy__1.png +
+
+
    +
  • + +above hierarchy exists independent of the BTS/TRX/TS/lchan hierarchy + +
    • +
  • + +every TRX gets mapped to a phy_instance + +
    • +
+
+
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+

PHY link

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+
    +
  • + +A PHY link is a physical connection / link towards a given PHY. + This might be, for example, + +
      +
    • + +a set of file descriptors to device nodes in the /dev/ directory + (sysmobts, litecell15) + +
      • +
    • + +a packet socket for sending raw Ethernet frames to an OCTPHY + +
      • +
    • + +a set of UDP sockets for interacting with OsmoTRX + +
      • +
    +
    • +
  • + +Each PHY links has a set of attribute/parameters and a list of 1 to n PHY instances. + +
    • +
  • + +PHY links are numbered 0..n globally inside OsmoBTS. + +
    • +
  • + +Each PHY link is configured via the VTY using its individual top-level + vty node. + +
    • +
  • + +The PHY links and instances must be configured above the BTS/TRX nodes in the configuration file. If the file is saved via the VTY, the code 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. + +
    • +
  • + +In the case of osmo-bts-sysmo and osmo-bts-trx, there is only one + instance in every PHY link. This is due to the fact that the API + inside that PHY link does not permit for distinguishing multiple + different logical TRXs. + +
    • +
  • + +Other PHY implementations like the OCTPHY however do support addressing multiple PHY instances via a single PHY link. + +
    • +
  • + +PHY instances are numbered 0..n inside each PHY link. + +
    • +
  • + +Each PHY instance is configured via the VTY as a separate node beneath each PHY link. + +
    • +
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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 +order to specify which PHY instance is allocated to this specific TRX.

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The End

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Questions?

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