[Openbts-discuss] P2.8 release and USRP / UHD device support

[Thomas T. <tt...@vt...>]

David and Community,

I've been testing P2.8 with the updated Transceiver52M this week and
I'm pleased with the way it's running. A number of changes went in
since the last major UHD branch update. The biggest change is the
complete removal of the non-52MHz transceiver and integration of
sample rate conversion into Transceiver52M; support for all Ettus
Research devices is consolidated through Transceiver52M only. Also
note that support for USRP1 at 64MHz has been removed.

Various device options - listed further below - are selected at
compile time. For example, there is no need to manually modify any
code to enable single USRP1 daughterboard use. UHD devices (including
the B100) are automatically detected, though resampling may need to be
explicitly enabled.

---- OpenBTS-P2.8 ----

I rebased the Transceiver52M patch series onto svn trunk r2342, the
most recent Transceiver52M commit. They are available as a patch set
or in the following P2.8 git repository in the default usrp branch.

  Git:
    git clone git://github.com/ttsou/openbts-p2.8.git

  Patchset:
    http://ttsou.github.com/openbts-uhd/Transceiver52M-patches.tar.gz

  Github:
    http://github.com/ttsou/openbts-p2.8/tree/usrp

I didn't squash much of the 60 patch series, but I can do that or make
other format changes if it makes svn merging easier. The changes do
merge smoothly with git-svn back into my replicated svn repo (against
r2377) without conflict.

---- OpenBTS-UHD ---

I pushed the same patchset - minus a few P2.8 specific ones - to the
openbts-uhd master branch.

    git://github.com/ttsou/openbts-uhd.git

As for the future of OpenBTS-UHD, I will continue to maintain the tree
in the short-term since myself and others still have development
dependencies on it. That may change as projects complete and/or merge
into P2.8.

Also, I will keep an OpenBTS-P2.8 git repo - with the master branch
tracking mainline svn trunk - because I have a distaste for
Subversion. I know that David feels the same way about Git, so
hopefully we can accommodate our preferential differences.

---- Device Configuration Options ----

Mandatory options depend on the device type. Parameters in brackets
are optional.

   ---- USRP1 ----

    ./configure --with-usrp1 [--with-singledb]

The usrp1 option enables special USRP1 support with timestamps using
the gnuradio driver. GNU Radio is required, but not UHD. The single
daughterboard switch assumes side A. If not specified, the default
configuration is Tx A / Rx B.

    ---- USRP2 / N2xx  ----

    ./configure --with-resamp [--with-extref]

All non-USRP1 devices use the Ettus UHD driver; GNU Radio is not
required. USRP2 and N2xx devices are not currently configurable at the
GSM symbol rate and thus require resampling to be enabled. An external
10MHz reference is optional, but recommended.

    ---- B100 / E100 ----

    ./configure [--with-resamp] [--with-extref]

The B100 can operate at the recommended 52MHz or 64MHz with the
software resampler enabled. The E100 can configure itself for either
configuration, but will only work with OpenBTS at 52MHz due to
resource constraints.

  Thomas