Before this patch we had:
* osmo-bts-trx internally using 1/256th bit/symbol period
* osmo-bts-sysmo internally using 1/4 bit/smbol period
* PCU interface using 1/4
* L1SAP interface using 1/4
* measurement processing code on top of L1SAP using 1/256
So for sysmo/lc15/octphy we are not loosing resolution, but for
osmo-bts-trx we're arbitrarily reducing the resolution via L1SAP
only then to compute with higher resolution again.
Let's change L1SAP to use 1/256 bits and hence not loose any resolution.
This requires a corresponding change in libosmocore for l1sap.h, which
is found in Change-Id Ibb58113c2819fe2d6d23ecbcfb8b3fce4055025d
Change-Id: If9b0f617845ba6c4aa47969f521734388197c9a7
Measurement reports fed into L1SAP so far had their frame number always
set to zero, resulting in higher-layer common code above L1SAP to never
detect the end of the measurement period, which in turn caused no RSL
MEAS REP to be sent.
Related: OS#2978
Change-Id: I67837d19515ea335614928570c12dd5027104c6b
Let's make sure whenever we do have a frame number, we print it as
context in the related log line
Change-Id: I751d5ddb3322fce489bc241459738cbcc55c890b
The problem is that measurement processing above L1SAP requires/expects
those PRIM_INFO_MEAS indications from the bts specific parts. Otherwise
it will never generate even uplink-only measurement reports to the BSC,
which is a violation of Abis protocol specs.
Change-Id: I48f73293cb4f0ab4c657dfd00e7ddd032a3c030f
Commit 5eb17e28ac added this warning when
implementing the full function. However, other backends seem to be also
passing the primitive from the stack to l1sap_up without any visible issues.
Furthermore, according to the documentation of l1sap_up, it takes ownership of the
msgb, but doesn't take ownserhip of the prim itself.
Change-Id: I45fe40e3377eac999d1dac5356678195381d94ca
In bts_model_l1sap_down() we want to identify BCCH/CCCH channel numbers,
but our check is a bit non-specific. Let's make the check more specific
to only cover the BCCH, Uplink CCCH and Downlink CCCH C-bits as defined
n 3GPP TS 08.58 Section 9.3.1
Change-Id: Ia20ab09b96c87c0dfbfaf98e5b2a8d36423fac67
In a larger simulated network with multiple BTSs it is normal that one
BTS will see GSMTAP frames for an ARFCN that is not an ARFCN used by the
local BTS. This is just normal operation.
Change-Id: Ic68cace9648ccb17500c94b6ede8814674aa9c29
It is important that we reliably terminate the BTS in case any of the
VirtPHY multicast sockets dies for whatever reason.
Change-Id: I5ae3fdd7cc35fdf235550a3b8362020fdd287c13
The defaults must be set during bts_model_phy_link_set_defaults()
and can then later be overridden by the vty (from the config file).
They should only be written back to the file if they differ from
the default settings.
Change-Id: I5d7f2c1dc8bc3d11db5c607b664730e4dcd58c96
This patch adds a virtual physical layer designed to simulate the
Um air interface between BTS and MS. It does so by encapsulating MAC
blocks (Layer 2 PDUs) via GSMTAP and sending them through multicast UDP
streams, both in uplink and in downlink.
The purpose of this is enable testing without any radio hardware or
related licenses.
OsmocomBB has recently received as similar patch-set, adding a virty_phy
executable that can be run on a PC instead of the classic 'layer1'
firmware on a real phone.
Using GSMTAP means that one can use unmodified wireshark to decode the
messages exchanged on the virtual Um layer.
This code was originally started by Harald in January 2016, continued
by Sebastian Stumpf in late 2016 and early 2017, and finally completed
by Harald in July 2017.
Change-Id: I1bf7670975b1e367c1c62983020865a043542622
Oliver Smith
Harald Welte
Pau Espin