21 Communications Squadron (21CS) has a requirement for Local Telecommunication Services (LTS), a comprehensive description of local exchange access services, Internet Protocol (IP) access transport s... 21 Communications Squadron (21CS) has a requirement for Local Telecommunication Services (LTS), a comprehensive description of local exchange access services, Internet Protocol (IP) access transport services, and intra-Local Access Transport Area (LATA) interconnect functions for Space Base Delta 1(SBD1) and Space Base Delta 41 (SBD41).