TACS

REMORA Category: T

The Total Access Communication System (TACS) was an analog mobile communications system, initially used in the United Kingdom and later adopted by over 25 other countries. Here’s an overview of its key features and history:

  1. Origin and Development: TACS is a derivative of the American Advanced Mobile Phone System (AMPS), developed by AT&T. While based on the AMPS standard, TACS made several modifications to adapt to different regional requirements.
  2. Frequency and Bandwidth Differences: The primary differences between TACS and AMPS were in the radio frequencies used, the radio channel bandwidth, and the data signalling rates. These changes were necessary to fit the specific spectrum allocation and telecommunication standards of the regions where TACS was deployed.
  3. Introduction in the UK: TACS was introduced in the UK in 1985 and marked a significant development in the country’s mobile telecommunications sector. Its introduction was highly successful, paving the way for the widespread adoption of mobile phone technology.
  4. Operational Frequency Bands: TACS operated in the 890-915 MHz and 935-960 MHz bands. This frequency range was later also used by the GSM (Global System for Mobile Communications), which is a digital mobile telephony system.
  5. Channel Bandwidth and Duplex Channels: TACS had a radio channel bandwidth of 25 kHz, narrower than the 30 kHz bandwidth of AMPS. This reduction in bandwidth allowed TACS to offer 1000 duplex channels in the 900 MHz band. However, the narrower bandwidth also meant that the data signalling rate had to be reduced compared to AMPS.
  6. JTACS in Japan: A modified version of TACS, known as JTACS (Japanese Total Access Communication System), was used in Japan. The main distinction of JTACS from the original TACS was the different radio frequency band in which it operated, tailored to fit Japan’s specific telecommunications infrastructure and spectrum allocation.
  7. Transition to Digital Systems: Eventually, like other analog systems, TACS was phased out in favor of newer, digital mobile communication technologies like GSM, which offered higher capacity, better security, and more advanced services.

The development and deployment of TACS represent a critical phase in the evolution of mobile telephony, bridging the gap between the first generation of analog mobile phones and the subsequent digital systems.