Total Access Communication System

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Mobile communication standards

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cdmaOne / CDMA2000 (3GPP2) Family

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AMPS Family

AMPS (1G) TACS / ETACS

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Channel Access Methods FDMA OFDMA TDMA SSMA CDMA W-CDMA

Frequency bands Cellular GSM UMTS PCS SMR

Total Access Communication System (TACS) and ETACS are mostly-obsolete variants of AMPS which were used in some European countries (including the UK & Ireland in 1983). TACS was also used in Japan under the name Japanese Total Access Communication (JTAC).^[1][1][2][2] It was also used in Hong Kong ^[3]. ETACS was an extended version of TACS with more channels.

TACS and ETACS are now obsolete in Europe, having been replaced by the GSM system. In the United Kingdom, the last ETACS service operated by Vodafone was discontinued on 31 May 2001, after sixteen years of service. ETACS is however still in use in a handful of countries elsewhere in the world. NMT is another analog cellular standard that was widely used in Europe, mainly in the Nordic countries, which has now been fully replaced by GSM except for limited use in rural areas due to its superior range.

[edit] Frequency bands used by ETACS in the UK

Channel	Cell TX (MHz)	Mobile TX (MHz)	Notes ..............
1	935.0125	890.0125	25 kHz spaced channels
23	935.5625	890.5625	1st of 21 dedicated vodafone control channels
24	935.5650	890.5650	2nd of 21 dedicated vodafone control channels
300	942.4875	898.0625	9.5 kHz peak speech fm deviation
323	943.0625	898.0625	1st of 21 dedicated cellnet control channels
600	949.9875	904.9875	last TACS channel, ETACS extended this to 1320 later
0

TACS BAND Summary

Base TX Start	End (MHz)	Mobile start	End (Mhz)	BAND
935	950	890	905	TACS 600 Channels
935	960	890	915	TACS 1000 Channels
917	950	872	905	E-TACS 1320 Channels

[edit] UK ETACS and USA AMPS compared

Feature	TACS	AMPS	Notes ..............
Channel Spacing	25 kHz	30 kHz
Speech peak Freq Dev	9.5 kHz	12 kHz
Signalling FSK peak Freq Dev	6.4 kHz	8 kHz
Signalling rate	8 kbit/s	10 kbit/s
SAT 0	5970 Hz	5970 Hz
SAT 1	6000 Hz	6000 Hz
SAT 2	6030 Hz	6030 Hz
ST	8000 Hz
Mobile TX pwr MAC 0	2.82 W
Mobile TX pwr MAC 1	1.12 W
Mobile TX pwr MAC 2	447 mW
Mobile TX pwr MAC 3	178 mW
Mobile TX pwr MAC 4	70.8 mW
Mobile TX pwr MAC 5	28.2 mW
Mobile TX pwr MAC 6	11.2 mW
Mobile TX pwr MAC 7	4.5 mW

[edit] References

1. ^ ^{a b} GSM Terma, volny.cz. Article retrieved 2006-01-19.
2. ^ ^{a b} Japanese Total Access Communication (JTAC), mobiledia.com. Article retrieved 2007-01-19.
3. ^ Cellular Networks QuickStart: Getting up to Speed on Cellular, from 1G to 3G, devx.com. Article dated 2003-03-17, retrieved 2007-01-19.

BT Engineering Journal Vol 4 July 1985

Smith Myers ART 775 User Manual