Changes between Version 38 and Version 39 of Tutorials/g0WmLTE/Tutorial5

Timestamp:

Jul 12, 2016, 12:20:28 PM (9 years ago)

Author:

seskar

Comment:

—

Tutorials/g0WmLTE/Tutorial5

@@ -14 +14 @@
  1. It will take roughly 60 seconds to come up.
 1. {{{ ssh root@node7-1.grid.orbit-lab.org }}}
+
 === Commands on the node ===
-By Default Orbit nodes do not configure any wireless devices. The following 2 are the drivers for the Sierra wireless Netgear LTE dongle [[BR]]
-1. {{{ modprobe GobiSerial }}}
-1. {{{ modprobe GobiNet }}}
-1. {{{ minicom -D /dev/ttyUSB1 }}}
-1. {{{ AT!ippassthrough? }}}
- 1. It should return 1
- 1. If it does not, run the following commands:
-  1. {{{ AT!ippassthrough=1 }}}
-  1. {{{ AT!entercnd="A710" }}}
-  1. {{{ AT!dxcfg=profile,Autoconnect,Never }}}
-  1. {{{ AT!reset }}}
-1. {{{ AT!entercnd="A710" }}}
- 1. You should see {{{ OK }}}
-1. {{{ AT!dxcfg=wwan,connect,11 }}}
- 1. You should see {{{ OK }}} then {{{ $QCRMCALL: 1, V4 }}}
-1. {{{ at!gstatus? }}}
- 1. Will return a status like: 
+
+==== Loading the driver ====
+
+By Default Orbit nodes do not configure any wireless devices so the first thing, when manually configuring the device is to load the drivers; the following 2 lines will load the Sierra wireless Netgear LTE dongle:[[BR]]
+{{{ 
+modprobe GobiSerial
+modprobe GobiNet
+}}}
+
+==== Connecting to the device ====
+Control of the device is done over the serial port that is created by the driver (in this case '''/dev/ttyUSB1''') through a sequence of AT commands and you can use your favorite serial port communication program to talk to it; in this tutorial we will use '''Minicom''. To start to program execute:
+
+{{{ minicom -D /dev/ttyUSB1 }}}
+
+==== Managing the LTE connection ====
+
+Once in minicom, one can issue series of commands to the LTE modem typically consisting of:
+
+a.) Configure modem for pass-through mode:
+
+{{{ AT!ippassthrough? }}}
+
+It should return '''1''' . If it does not, run the following commands:
+    1. {{{ AT!ippassthrough=1 }}}
+    1. {{{ AT!entercnd="A710" }}}
+    1. {{{ AT!dxcfg=profile,Autoconnect,Never }}}
+    1. {{{ AT!reset }}}
+which will reset the modem.
+
+b.) 
+
+{{{ AT!entercnd="A710" }}}
+
+You should see {{{ OK }}}
+
+c.) Connect to the basestation:
+
+{{{ AT!dxcfg=wwan,connect,11 }}}
+
+You should see {{{ OK }}} shortly followed by {{{ $QCRMCALL: 1, V4 }}}
+
+d.) Check the status of the connection:
+
+{{{ at!gstatus? }}}
+
+Will return a status like: 
 {{{
 at!gstatus?                                                                                                         
@@ -49 +79 @@
 SINR (dB):      1.6
 }}}
-1. Exit Minicom by **PRESSING** {{{ Ctrl+A followed by x}}}, then {{{enter}}} to select ok.
-1. {{{ dhcpcd eth2 }}} followed by {{{enter}}} to get a new line.
- 1. You should get an address in the 192.168.3.0/24 subnet.
-1. {{{ ping 192.168.3.1 }}}
- 1. You have successfully communicated with the basestation.
- 1. You can cancel the ping with {{{Ctrl+C}}}
-1. Attempt running iperf between your nodes.
- 1. This will report your bandwidth to the basestation.
+
+The LTE link is established. Exit Minicom by **PRESSING** {{{ Ctrl+A followed by x}}}, then {{{enter}}} to select '''OK''' option.
+
+==== Testing the connection ====
+
+Once the modem is connected, IP address has to be assigned to the newly created Ethernet device (in this case '''eth2'''):
+
+{{{ dhcpcd eth2 }}} 
+
+The node should get an address in the 192.168.3.0/24 subnet (any existing dhcpd instance on eth2 has to be killed). Use ICMP to test connectivity with the default gateway:
+{{{ ping 192.168.3.1 }}}
+resulting in:
+{{{
+root@node1-7:~# ping 192.168.3.1
+PING 192.168.3.1 (192.168.3.1) 56(84) bytes of data.
+64 bytes from 192.168.3.1: icmp_seq=1 ttl=64 time=44.9 ms
+64 bytes from 192.168.3.1: icmp_seq=2 ttl=64 time=42.8 ms
+}}}
+The ping can be canceled with {{{Ctrl+C}}}. More elaborate link performance test can be done by using '''iperf''' between multiple nodes that are connected to the basestation.
+
+==== Reconnecting the client ====
+
+Use minicom (or any other serial port program) to issue a set of AT commands to reset the connection. Commands are:
+
+{{{
+AT!reset
+}}}
+
+(NOTE: after the AT!reset command the minicom will display the popup window that the connection was lost- one has to wait for the pop-up to go away before proceeding) 
+
+{{{
+AT!entercnd="A710"
+AT!dxcfg=wwan,connect,11
+}}}
+
+The output should look like:
+{{{
+root@node1-7:~# minicom -D /dev/ttyUSB1
+
+Welcome to minicom 2.7
+
+OPTIONS: I18n 
+Compiled on Jan  1 2014, 17:13:19.
+Port /dev/ttyUSB1, 06:02:02
+
+Press CTRL-A Z for help on special keys                 
+                                                        
+AT                                                       
+OK                                                      
+AT!reset                                                
+OK
+AT!entercnd="A710"
+OK
+AT!dxcfg=wwan,connect,11
+OK
+
+$QCRMCALL: 1, V4
+at!gstatus?
+!GSTATUS: 
+Current Time:  58               Temperature: 28      
+Bootup Time:   6                Mode:        ONLINE         
+System mode:   LTE              PS state:    Attached                           
+LTE band:      B25              LTE bw:      10 MHz                             
+LTE Rx chan:   8365             LTE Tx chan: 26365                              
+EMM state:     Registered       Normal Service                                  
+RRC state:     RRC Connected                                                    
+IMS reg state: No Srv                                                           
+                                                                                
+RSSI (dBm):    -69              Tx Power:    -33                                
+RSRP (dBm):    -90              TAC:         0001 (1)                           
+RSRQ (dB):     -5               Cell ID:     01A2D001 (27447297)                
+SINR (dB):     21.2                                                             
+                                                                                
+                                                                                
+OK                                                                             
+}}}
+
+Once connection is reset, dhcp lease needs to be renewed; if there is already dhcpd session it needs to be terminated:
+
+{{{
+root@node1-7:~# dhcpcd eth2
+err, eth2: dhcpcd already running on pid 2071 (/var/run/dhcpcd-eth2.pid)
+root@node1-7:~# kill 2071
+root@node1-7:~# dhcpcd eth2
+root@node1-7:~# dhcpcd.sh: interface eth2 has been configured with new IP=192.168.3.2
+
+root@node1-7:~# 
+}}}
+
+
+=== Managing the basestation ===
+
+Uses rest interface to manage the BS. To set the LTE connection bandwidth to 5 MHz issue the following commands on the console (not node):
+{{{
+wget http://bsc03out.orbit-lab.org:5054/bscontrol/bs/1/default_cell_parameters?n_rb_dl=25     
+wget http://bsc03out.orbit-lab.org:5054/bscontrol/bs/1/restart
+}}}
+
+Setting '''n_rb_dl''' to 50 sets it to 10 MHz while setting it to 100 sets the bandwidth to 20 MHz.
+After basestatin restart, most of the clients need to be also reconnected.
+