Using commercial eNodeBs in PhantomNet

How to use and configure a physical eNodeB

PhantomNet provides commercial eNodeBs for use by experimenters. Specifically, we currently have two ip.access e40 eNodeB devices available. (We expect to have more soon!) Each e40 is a dedicated LTE femtocell which can connect over the air to commodity UEs such as phones, tablets, or LTE modems. In most respects, they are self-configuring. They will automatically boot up and start talking to the OpenEPC infrastructure. We don't allow users to log onto these nodes directly. But we still provide an interface for changing some options and enabling logging information.

Creating your experiment

Before you can use an e40, you will have to add one to your experiment. You will need to add something like the below to your ns file:

# Add ip.access enodeb node #1
set penb1 [$ns node]
tb-fix-node $penb1 enodeb01
addtolan net_d $penb1

This creates a new node, specifies which e40 is uses, and adds that node to one of the management vlans.

Configuring Your eNodeB

The e40 must reboot each time you change the configuration. Because of this, the complete configuration (with defaults allowed) must be provided at once. Once you have created a configuration file (described below), you will need to use the e40-config.sh script:

e40-config.sh <ip> <configuration-file>

The script will contact the e40 at the given IP address and send it the specified configuration file. After the e40 changes the configuration, it will reboot to implement the changes. When the e40 reboots, all connections to both UEs and the MME will be terminated.

Configuration File

The configuration file consists of key/value pairs, one per line. Empty lines are permitted, and a line beginning with a '#' is ignored.

# Example Configuration File
# Here is a key/value pair
ReferenceSignalPower=-20
# All settings which are not explicitly specified are set to their default

The following keys are used for configuration:

ReferenceSignalPower` -- This is the base power level in dbm used for broadcasting messages to the UE. Default: -10 Max: 5

A debugging interface called FAPI is provided for logging messages in the RAN. Enabling this interface is very resource-intensive and so may perturb the results of your experiment. When enabled, a tcpdump stream is sent to a specified address and port in real time which you can save or analyze. A proprietary parser, described elsewhere, must be used to analyze the stream.

FAPI_IP -- The destination IP address for the tcpdump stream. Default: 0.0.0.0
FAPI_Port -- The destination port for the tcpdump stream. Default: 8888

The following boolean flags indicate which messages on the RAN should be sent to the above IP and port. Set to '1' to enable:

FAPI_PhyErrorInd -- Default: 0
FAPI_PhyDlCfgReq -- Default: 0
FAPI_PhyUlCfgReq -- Default: 0
FAPI_PhyUlSfInd -- Default: 0
FAPI_PhyDlHiDci0Req -- Default: 0
FAPI_PhyDlTxReq -- Default: 0
FAPI_PhyUlHarqInd -- Default: 0
FAPI_PhyUlCrcInd -- Default: 0
FAPI_PhyUlRxUlschInd -- Default: 0

Using the e40

Once you have configured your e40, it will automatically connect to the MME. You should see something like the following in your MME logs:

10(11032) 10:51:36 INFO:sctp_socket_accept():444> Notification 32769 to socket 13 received
14(11038) 10:51:36 INFO:mme_s1ap_recv_S1_SETUP_REQUEST():371> Received an S1AP Setup Request message
14(11038) 10:51:36 INFO:mme_s1ap_send_S1_SETUP_RESPONSE():281> Preparing the S1AP S1 Setup Response message
14(11038) 10:51:36 INFO:mme_s1ap_send_S1_SETUP_RESPONSE():345> Successfully sent the S1AP S1 Setup Response message
14(11038) 10:51:36 INFO:mme_s1ap_recv_S1_SETUP_REQUEST():432> Successfully processed the S1AP S1 Setup Request message

At this point, any UE with a key and IMSI in the MME's database can connect through the e40.

Rebooting

If you need to reboot the e40, simply reconfigure it and it will automatically reboot.

Questions

For any other questions, contact phantomnet-users@emulab.net