Data Time Slots These   are   the   time   slots   during   which   users transmit  or  receive  data.  There  are  three  segments  of time  slots  in  each  frame,  designated  A,  B,  and  C. Segment  A  may  contain  from  one  to  five  circuits;  B may  contain  from  one  to  eleven  circuits;  and  C  may contain from one to six circuits. The number of circuits in each group depends on the baseband data rate, the forward   correction   rate,   and   the   transmission   burst rate, as influenced by the radio frequency interference (RFI) environment. Current Operation For   communications   on   the   eastern   Pacific satellite,   a   master   control   station   is   installed   at NCTAMS  EASTPAC.  This  same  pattern  of  DAMA equipment   installations   has   been   followed   at NCTAMS   LANT,   MED,   WESTPAC,   and   NTCS. Each  master  control  station  has  multiple  multiplexer installed,   and   each   TD-1271B/U   multiplexer   can accommodate   up   to   four   circuits.   The   number   of multiplexer   installed   aboard   each   ship   varies according to platform requirements. Any  DAMA-equipped  platform  with  full-duplex capability can be designated a channel controller. This capability  provides  an  emergency  backup  for  the shorebased   master   controller   terminals.   A   DAMA subscriber who is designated a channel controller will provide  all  the  required  CCOW  functions  for  DAMA system control of a particular rf channel. Operationally,  the  user  terminal  will  have  its baseband port automatically connected to a data time slot  when  the  proper  slot  number  is  keyed  into  the multiplexer   front   panel   keyboard.   Each   SATCOM subsystem  that  uses  DAMA  will  have  a  specific  slot number. Circuits will normally be operated on a netted basis,   and   circuit   numbers   will   be   assigned   by COMNAVTELCOM  and/or  FLTCINC. Transition Transition  to  DAMA  is  taking  place  in  a  manner that   allows   subscribers   converted   to   DAMA   to communicate with those who have not been converted. During  the  transition  period,  equipment  installed at   shorebased   master   stations   will   form   gateways between   DAMA   and   non-DAMA   circuits.   In   the following paragraphs, we will discuss subsystems that are either currently undergoing conversion to DAMA 3-16 or are planned for conversion, so you will know what to expect in the future. Secure Voice  —DAMA is now being phased into the   Secure   Voice   Subsystem.   A   DAMA-configured Secure Voice Subsystem is shown in figure 3-12. CUDIXS/NAVMACS   —NAVMACS   platforms will   be   gradually   transitioned   to   DAMA.   This transition   will   start   when   CUDIXS   shore   and CUDIXS/NAVMACS   ship   hardware   and   software have been modified for compatibility with DAMA. At that  time,  a  transition  will  begin  allowing  DAMA  or non-DAMA  ships  to  communicate  with  the  CUDIXS shore   terminal.   A   DAMA-configured   CUDIXS/ NAVMACS subsystem is shown in figure 3-13. Teletypewriter —Teletypewriter capability via DAMA  becomes  available  as  DAMA  is  installed  on each platform. To provide maximum flexibility during the transition, capability is provided at the shorebased master  control  stations  to  interface  non-DAMA  and DAMA users. Figure 3-14 shows a DAMA-configured teletypewriter  subsystem. CONTROL  SUBSYSTEM The  Control  Subsystem  is  structured  to  perform the following tasks: Sense and collect system status information in a defined  geographical  area  and  on  a  worldwide scale. Control  system  resources  and  the  degradation of system capability. The Control Subsystem is a combination of several areas  and  levels  of  command.  The  major  players  are listed below: The Chief of Naval Operations is the executive authority  for  all  SATCOM  system. The   Commander,   Naval   Space   Command   is responsible  for  the  operational  control  and  management of  these  systems  and  for  the  effective  operation  and maintenance   of   assigned   Navy   resources   for   the Department of Defense. The  Naval  Computer  and  Telecommunications Command   performs   the   required   functions   to   pro- vide day-to-day control and operation of naval satellite communications   assets.   With   coordination,   system resources can be adjusted to meet operational needs.