Traffic Service Position System

TSPS stands for Traffic Service Position System; it was a system invented by Bell Labs in Columbus, Ohio to replace traditional cord switchboards. The first TSPS was deployed in 1969 and used the Stored Program Control-1A CPU, "Piggyback" twistor memory, a proprietary technology developed by Bell Labs similar to core memory, and IGFET Insulated Gate Field Effect Transister solid state memory devices similar to DRAM Dynamic Random Access Memory.

The TSPS system utilized special analog trunks that originated at Class 5 End Office circuit switch systems and Class 4 Toll Access circuit switch systems that were connected to Class 3 Primary Toll circuit switch systems such as the 4A-ETS/PBC and 4ESS switch systems. The TSPS system DID NOT perform switching between the originating end office switch and the toll switch for the subscriber voice path.

The TSPS system included a feature known as "Remote Trunking Arrangement" or (RTA) that consolidated the trunk connection at the originating switch and provided a switched connection to an operator only as required for a short duration at the beginning of a call to obtain billing information or at the end of a call in which the caller requested "time and charges". See the Bell System Technical Journal for several articles on the TSPS system and RTA enhancement. It is noteworthy that some telecommunications manufacturers claimed intellectual property rights in the late 1990's on the RTA concept developed by Bell Labs in the 1970's.

The TSPS system provided a temporary switched connection to a Toll Operator who helped facilitate calls requiring human assistance such as Person-to-Person, Collect, Third-Party-Billed, and Hotel Billing. The TSPS system supported up to seven "Chief Operator Groups" (COGs) with each COG supporting up to 31 operator consoles. Operator consoles initially used nixie tube displays that were quickly replaced by Light Emitting Diode displays due to reliability issues.

The TSPS system included the "Hotel Billing Information System" special feature to provide automated billing of long distance calls from hotel front desks so guests could be charged for calls made almost immediately prior to their departure. Private teletype data links were provisioned to large hotels that subscribed to this service.

The TSPS system was ultimately replaced by the OSPS or Operator Service Position System feature package developed for the Number 5 ESS switching system. During the era of TSPS systems, calls to mobile and marine customers were initially handled by operators at a SOST cord board. Operator assisted calls to international destinations were handled by "Code 10" and "Code 11" operators generally collocated at special International Switching Systems.

• ATIS definition
• TSPS system history
• TSPS definition 47CFR part 67 Appendix
• US Patent #3,731,000 for "Equipment for Switching Calls from Remote Trunk Groups to Distant Centralized Operator Service Center", Amos E. Joel, Bell Laboratories, Murray Hill, NJ
• US Patent #4,145,578 for "Position Access Preference Method", Richard Orriss, Bell Laboratories Columbus, OH
• US Patent #4,197,430 for "Operator Service Position System", Douglas C. Dowden, Bell Laboratories, Columbus, OH