So SDR is all well and good, but a late night eBay purchase landed me two ipaccess NanoBTS units second hand from the US.

The hefty metal units are designed as GSM access points / picocells for indoor use, with a stable Uu / radio interface and speaking Abis over IP, it integrates nicely with Osmocom’s stack and was used by the Osmocom team as a bit of a development platform in the past.

Finding the Current IP

Because these units are second hand, first step was finding the current IP.

I ran a packet capture on the interface the units were plugged into until I saw some traffic showing their current IP.

Once you’re in the correct subnet you can use the abisip-find tool to find any units:

abisip-find 

Mine showed up on a 10.97.99.15 IP, so I put my machine on the 10.97.99.x/24 subnet so I could reach them.

Changing IP Details

Once I had the current IP details it was time to change the IP details, Unit ID and OML / AbisIP IP address.

My unit came on 10.97.99.15, but I wanted it on 10.0.1.204/24 and pointed to my BSC at 10.0.1.201, so I set that using the command,

ipaccess-config -u 1801/0/0 -o 10.0.1.201 -i 10.0.1.204/24 -g 10.0.1.1 -r 10.97.99.15

Provisioning on the BSC

Finally I just had to provision the BTS on the BSC like any we did for our Virtual and SDR based BTS (Link for reference)