They do have support facilities and prepared launch areas, but there is no hard requirement for PLARF units to operate exclusively out of those positions. Launch Battalions are able to deploy, emplace, and operate from just about any suitable location as long as the requisite Brigade-level (or higher in rare cases) support is arranged.i dont know but i think a SRBM bde is probably even more difficult to maintain and support, which is why i think maybe they have some sort of pre designated location for operation, cannot just move to any random place and be operational