AT&T Inc. has asked permission from the Federal Communications Commission (FCC), to shut down the 13 legacy TDM (Time-division multiplexing) services of its wholly owned subsidiary – Southwestern Bell Telephone Company. The decision to terminate the services stems from lack of demand. Southwestern Bell Telephone Company operates in Arkansas, Kansas, Missouri, Oklahoma, Texas and parts of Illinois.
“AT&T currently has no customers that subscribe to these service options and has not had any requests seeking these service options in the previous two years,” AT&T said in its FCC filing. The service is expected to shut down effective Feb 28, 2017, subject to FCC approval.
The services to be shut down include Telegraph Bridging Four-Wire Capability, Voice-grade Active Telemetry and Alarm Bridging Split Band Capability. Telegraph Bridging Four-Wire Capability offers bridging functions on a telegraph grade circuit that connect three or more customer-designated building in a multipoint arrangement. Voice-grade Active Telemetry and Alarm Bridging Split Band Capability is a Telemetry and Alarm bridging network which divides the voice band into two portions, one for each direction of transmission.
TDM service discontinuation has become a growing trend in the wireline segment of the telecom industry. Telecom service providers are moving toward IP-based networks as an increasing number of enterprise customers are opting for IP-enabled cloud services.
AT&T earlier requested the FCC for permission to discontinue a series of legacy services including collect calling, person-to-person calling, bill to third party, Busy Line Verification, Busy Line Interruption and International Directory Assistance in Jun 2016.
Besides AT&T, national telecom carriers like Sprint and Verizon Communications have opted for similar service discontinuation. Verizon seek the FCC’s nod to stop providing postpaid calling card and personal 800 services while Sprint asked to discontinue long-distance voice services. Level 3 Communications has sought permission from the FCC to discontinue its legacy voice services based on outdated TDM (time division multiplexing) technology.