Commit Graph

3 Commits

Author SHA1 Message Date
Pau Espin fbb8611381 gnuradio zmq broker refactoring
First step towards support everal ENBs and installing the remote script
at runtime:

* The gnuradio broker class is moved to its own file, to decouple it
  from RFemu.
* The ENBs are registered earlier in the test so that the GrBroker knows
  when to start (delay start + setup until all ENBs have been configured).
* Handle ENBs internally as a list.

Change-Id: I4f1095bbc7ed0a816fe47caef44f7becadd9d737
2020-10-16 18:23:58 +02:00
Andre Puschmann d5579fa38e rfemu_gnuradio_zmq: fix amplitude conversion
fix dB to amplitude conversion and adjust max attenuation value

Change-Id: I5a94d5d31e7dc85ab37bd281f95374ad825a41ff
2020-10-16 14:17:36 +00:00
Pau Espin 410912333e 4g: Introduce ZMQ GnuRadio stream broker
srsENB currently creates 1 zmq stream (1 tx, 1 rx) for each cell (2 if
MIMO is enabled). Each cell transceives on a given EARFCN (and several
cells can transmit on same EARFCN).

However, for handover test purposes, we want to join all cells operating
on the same EARFCN to transceive on the same ZMQ conn, so that an srsUE
can interact with them at the same time (same as if the medium was shared).
Furthermore, we want to set different gains on each of those paths
before merging them in order to emulate RF conditions like handover.

In order to do so, a new element called the Broker is introduced, which
is placed in between ENBs and UEs ZMQ conenctions, multiplexing the
connections on the ENB side towards the UE side.

A separate process for the broker is run remotely (ENB run host) which
listens on a ctrl socket for commands. An internal Broker class is used
in osmo-gsm-tester to interact with the remote script, for instance to
configure the ports, start and stop the remote process, send commands to
it, etc.
On each ENB, when the rfemu "gnuradio_zmq" rfemu implementation is selected
in configuration, it will configure its zmq connections and the UE ones to
go over the Broker.

As a result, that means the UE zmq port configuration is expected to be
different than when no broker is in used, since there's the multiplexing
per EARFCN in between.

In this commit, only 1 ENB is supported, but multi-enb support is
planned in the future.

The handover test passes in the docker setup with this config:
"""
OSMO_GSM_TESTER_OPTS="-T -l dbg -s 4g:srsue-rftype@zmq+srsenb-rftype@zmq+" \
	"mod-enb-nprb@6+mod-enb-ncells@2+mod-enb-cells-2ca+suite-4g@10,2+" \
	"mod-enb-meas-enable -t =handover.py"
"""

and in resources.conf (or scenario), added:
"""
enb:
  ...
  cell_list:
    - dl_rfemu:
       type: gnuradio_zmq
    - dl_rfemu:
        type: gnuradio_zmq
"""

Note that since the broker is used, there's not need for mod-srsue-ncarriers@2
since the broker is joining the 2 enb cells into 1 stream on the UE side.

Change-Id: I6282cda400558dcb356276786d91e6388524c5b1
2020-10-15 12:34:36 +00:00