The twelve are part of a Joint Incident Site Communications Capability team. In other words, the CNG and the JISCC are going to DC with the POTUS.
They "will provide communications capabilities to contingency operations in direct support of the presidential inauguration," Major General Thaddeus Martin said in a press release.
With their help, different agencies can communicate with each other via satellite, radio, telephone and internet connectivity.
Whatever they're doing, they're getting a front row seat to history.