== OAI RRH on ORBIT, eNB Running on GENI

This tutorial assumes you have a GENI account, and can reserve resources in the Rutgers instageni rack, as well as the Rutgers ORBIT testbed. You will need a reservation for grid.orbit-lab.org

 * Instructions on logging into ORBIT via GENI Portal are [http://wimax.orbit-lab.org/wiki/dSite/oGeniPortal#GENIPortalAccess here]
 * Overview of GENI wireless testbed as an Edge computing resource are [PID4355919.pdf here]
   
 [[Image(OAI_USRP_GENI.PNG)]]
This example uses node18-2 in the ORBIT Grid as the RRH, node 19-3 as the client, and pc4.instageni.rutgers.edu as the remote eNB, with the mme.orbit-lab.org acting as the EPC.

1. Setup
 1. GENI
  1. With a valid GENI Project and Slice, use the attached RSPEC to reserve resources in the Rutgers Instageni Rack.
   1. [attachment:pc4_rspec.xml attached rspec]
   1. You will need to modify it to ensure your SSH keys are added properly.
 1. ORBIT
  1. Execute the following commands on the grid console, from separate ssh sessions (They can be done at the same time)
   1. {{{ omf load -t node18-2 -i oai-rrh.ndz }}}
   1. {{{ omf load -t node19-3 -i baseline.ndz }}}
  1. After they are imaged, turn the nodes on
   1. {{{ omf tell -a on -t node18-2,node19-3 }}}
1. Execution
 1. Open a ssh session to each device
  1. {{{ ssh username@pc4.instageni.rutgers.edu }}}
  1. {{{ ssh root@node18-2.grid.orbit-lab.org }}}
  1. {{{ ssh root@node19-3.grid.orbit-lab.org }}}
 1. On node18-2
  1. Run script {{{ ./quickbuild_rrh.sh }}}
  1. Run {{{ ~/openairinterface5g/cmake_targets/rrh_gw/build/rrh_gw -n1 -i eth1 -m0 -x }}}
 1. On pc4.instageni.rutgers.edu
  1. {{{sudo /opt/openairinterface5g/cmake_targets/lte_build_oai/build/lte-softmodem -O /opt/conf/enb.band25.tm1.rrh.usrpb210.conf}}}
   1. which is to launch the softmodem with a known good configuration file. 
   1. Add the {{{-x}}} flag to use visualizations over X11 forwarding.
   1. To use a different grid node as the RRH, you must edit the config file line {{{ remote_address = "10.10.18.2";}}} to the appropriate IP.
 1. After executing both run scripts, you should see the RRH node load a USRP image, and the eNB node start printing log messages.
 1. On node19-3
  1. Follow the instructions from the [wiki:Tutorials/g0WmLTE/Tutorial3 COTS UE tutorial] to connect.
  1. The UE should get an address, and be able to send traffic to the WAN.
  1. You will start seeing messages appear in stdout on the RRH and eNB.
  1. If you see messages like {{{UUULLULULLL}}} on either, the interfaces are experiencing under/overrun. This is caused by not meeting the roundtrip deadlines, either from processing power limits, or latency between the RRH and the eNB.