Paging network

In a radio paging network , particularly in the early days of mobile telephony, the simplest alarm information ("beeper") or short messages were transmitted to radio message receivers , also known as "pagers". In the private user area this function has been largely from the mobile phone or the mobile - Short Message Service ( SMS accepted). In Austria, after the pager services of Mobilkom Austria were finally discontinued in 2002, new pager networks on a digital basis were set up from 2005 because they have decisive advantages over mobile phone networks in time and security-critical applications. In Germany and France, the nationwide radio paging networks have been operated by e * Message Wireless Information Services GmbH ( eMessage ) since 2000 .

Active systems

e * city call

Various digital receivers for paging services

→ Main article : Cityruf

e * Cityruf is the name of an alerting and notification service in Germany operated by the Berlin provider eMessage . With e * Cityruf, messages are transmitted by radio from the e * Cityruf transmitter to the portable e * Cityruf receiver. The public Cityruf trial operation began in November 1988 in Berlin and Frankfurt am Main , and in March 1989 Cityruf was officially introduced as a service of the Deutsche Bundespost TELEKOM . In May 1990 it was also introduced by Deutsche Post in the starting region of Leipzig as the only radio paging service in the GDR , apparently in anticipation of the foreseeable reunification .

At the end of 1999, e * Message took over all of DeTeMobil's (now T-Mobile ) paging services , including e * Cityruf. e * Cityruf is broadcast throughout Germany or in so-called call zones (16 in total), often with better network coverage than that of mobile phone networks, especially at times of high network load (New Year's Eve, major events, major incidents).

There are three types of e * Cityruf receivers in the e * Cityruf: Tone-only receivers, numeric receivers and alphanumeric receivers. The entry is made depending on the call class of the recipient with different access numbers, for example via the Internet via the e * Message website, by e-mail or telephone. A manual operator is also available for entering numeric or alphanumeric messages. The call is sent using the area code 0164 plus the phone number .

e * BOS alerting

e * BOS-Alerting is the name of an alerting service especially for authorities and organizations with security tasks (BOS). The e * BOS alarm network is operated by e * Message . Working in the 70 cm range and in highly synchronous single-wave operation, it ensures uniform coverage of the defined alarm areas within seconds. The overlapping radio cells ensure a high quality of supply and redundancy. The responsible control center sends a simultaneous alert to the necessary emergency services in the entire alerting area. The e * BOS alerting includes consulting, planning, approval, construction, operation, service and maintenance as a complete service. The users include fire brigades and rescue services from districts and cities in Germany as well as plant fire brigades at airports, industrial parks and companies.

NP2M

Paging, a special technology in professional mobile radio, is based in most cases on the globally established transmission procedures POCSAG and FLEX, in Europe, with one nationwide exception, exclusively on POCSAG (Post Office Code Standardization Advisory Group). NP2M (Narrowband Point to Multipoint) includes paging and has developed into a separate transmission group recognized by CEPT (Conférence Européen des Administrations des Postes et des Télécommunications) and ETSI (European Telecommunications Standards Institute). NP2M enables applications that cannot be implemented with other systems, is very economical with the resources of energy and frequency, and can reach a large number of recipients with partially identical information at the same time with a high level of supply quality and economic efficiency. So z. For example, dynamically updated weather forecasts for several days in advance are transmitted to around three million satellite-based radio weather stations in German and French households. The transmission takes place via the nationwide radio paging networks of the e * Message group of companies. ETSI also sees the timely warning of the population for the following target groups as one of the main areas of application for NP2M: households, educational institutions, industry, first aiders such as emergency services and fire departments.

ERMES

ERMES (European Radio Messaging Services) is a radio paging service with a cellular structure, which was designed as a standardized European radio paging standard in the frequency range from 169.4 to 169.8 MHz and with 16 channels of 25 kHz bandwidth each. The introduction was decided by the CEPT countries in 1986. The number of frequencies to be used depends on the further expansion of the European network.

Made possible by the Telecommunications Act which came into force in Germany on August 1, 1996 , three nationwide and ten regional licenses and frequencies on an ERMES basis were auctioned off in September of the same year. However, the introduction had to be interrupted because ERMES severely disrupted cable television.

Iridium paging

→ Main article : Iridium

Iridium paging is a global paging service provided by the satellite operator Iridium . It is optionally available as follow-me paging in connection with an Iridium satellite telephone or as stand-alone paging. The stand-alone version was temporarily marketed by eMessage under the name e * Cityruf Global.

Inmarsat paging

→ Main article : Inmarsat

Inmarsat paging is a global paging service via satellite that was specially designed for use at sea.

Amateur radio paging

Radio amateurs operate their own digital radio paging network in Germany and neighboring countries based on the POCSAG transmission standard in the 70-centimeter band on the frequency 439.9875  MHz . Both modified, commercial transmitters as well as self-made solutions are used. In order to avoid mutual interference between the transmitters, a TDMA method with 16 time slots is used. The transmitters receive the content to be sent from servers networked with one another. There are two systems here: The older "radio call master" was designed for use with AX25 packet radio , the newer "Decentralized Amateur Paging Network", or "DAPNET" for short, is based on the TCP-IP protocol and handles the connections between the node computers and transmitters via the HAMNET . General information (propagation conditions, weather reports, DX clusters, etc.) as well as paging are sent out; Civil defense reports are planned. While the transmission of radio calls is reserved for licensed radio amateurs only, the evaluation of this radio frequency is permitted to everyone. This is possible with a suitable radio scanner , a sound card and software such as Poc32 .

Other radio paging networks

Alphanumeric pager that converts the received text into speech.

In Germany there are also numerous spatially limited radio paging services in the area of authorities and organizations with security tasks , which are used by them to alert emergency services by means of pagers.

Other radio networks are the Rhine radio network and the marine radio network.

Systems that are no longer active

Birdie

Birdie was a mobile phone service provided by the Deutsche Bundespost Telekom (hereinafter also referred to as Telekom), which enabled calls to be made with a cordless handset within a range of 50 to 300 meters from a specially marked switching station (primarily telephone booths). With the same handset, you could also make and receive both outgoing and incoming calls at home as usual with a corresponding home station. Telekom planned to set up birdie switching stations in busy places such as shopping centers, shopping malls, train stations and airports.

According to Telekom, the service, which was tested in a field trial from October 1990 to September 1991 in Münster (analog, CT1 +) and Munich (digital, CT2) , no longer had sufficient market opportunities in Germany , especially against the background of the D1 mobile communications service, which is in the starting blocks . Therefore, the field test was stopped in Munich in mid-1993.

In 1991 the basic monthly fee for birdie was DM 8.80 (adjusted for inflation, this corresponds to today's EUR 7.24) and the customer paid an additional DM 15 per month (corresponding to EUR 12.34) for their own home station. Calls made via a birdie station cost 0.39 DM (corresponding to 0.32 euros) per unit during the field test (local call at the normal rate) and calls made via the home station cost 0.23 DM (corresponding to 0.19 euros).

The general generic term for this type of cellular network was Telepoint. In other countries in Europe and Asia, this service was sometimes successfully carried out as a regular operation. The idea of ​​using the same device to make calls while on the move and - at more favorable conditions - at home is currently being implemented by mobile communications offers with “ Homezone ” (such as Genion from  O₂ ).

Chekker

Chekker was a public cellular service operated by Deutsche Bundespost Telekom , which enabled customers to communicate with each other using radio devices over a distance of up to a hundred kilometers. Chekker with ranges of up to 100 kilometers was used in particular by companies with branch offices and was intended to replace conventional company radio, which, with ranges of 10 to 15 kilometers, was only available for internal communication.

In 1990 the first Chekker radio networks were set up in Berlin and Frankfurt am Main, and a further eight cities were planned from 1991.

The radio services of the 28 private companies that have been competing with Telekom since 1992 were allowed to set up their own transmission paths between the radio stations since April 1993, which until then had to be leased from Telekom. Private radio services allow calls from radio to telephone and vice versa. Chekker only allowed radio-to-phone calls.

Chekker had a number of advantages over private commercial radio: The subscriber used the public radio network and there were no costs for setting up their own infrastructure (e.g. for setting up and maintaining a transmission tower). The calls were evenly distributed over the available channels (so-called trunked radio technology ); Frequencies that became available or were temporarily not used were immediately assigned elsewhere, so that waiting times for one of the limited frequencies are no longer necessary. By redistributing the channels during the call, a certain protection against eavesdropping was guaranteed.

At the beginning of 1993, a total of 27 Chekker radio networks were set up in Germany, ten of them in East Germany. 32,000 Chekker devices were registered with Telekom, 19,000 of them in the new federal states. In mid-1993, the device for the Chekker headquarters cost just under DM 4,000  (adjusted for inflation, around 3,000 euros), and a radio device around 2,500 to 3,500 DM (1,900–2,600 euros). To register the radio with Telekom, the customer paid 65 DM (48.68 euros) and the monthly fee per radio, which also covered all call costs, was 59.80 DM (44.79 euros).

In March 1999, the Chekker ProRegio Bündelfunk GmbH & Co. Deutschland KG was sold by Telekom to its competitor RegioKom . In a further step, RegioKom was renamed Dolphin Telecom (Deutschland) GmbH , which now continued the analog trunked radio networks of the former RegioKom, Quickfunk and Chekker. These networks were later combined under the common brand "Chekker".

At the end of July 2001, Dolphin Telecom (Deutschland) GmbH had to file for insolvency proceedings due to impending insolvency, but the Chekker network continued to operate. After the investor group Inquam stopped all further payments in October 2005, Dolphin Telecom had to go out of business. Parts of the Chekker network have been sold and are now being operated by other companies.

In August 2007 a new company called Dolphin Telecom GmbH started in Cologne, which had previously bought all name and domain rights from the insolvency administrator in England. This new Dolphin Telecom GmbH had no legal or economic connection to the former trunked radio operator Dolphin Telecom (Deutschland) GmbH . With the Dolphin service, the new Dolphin Telecom offered all mobile phone customers the option of using software installed on their mobile phones to make calls to expensive call destinations past their respective provider and at more favorable terms. This company also had to file for bankruptcy at the end of 2008.

Eurosignal

Eurosignal receiver

Eurosignal (as the European radio paging service EFuRD, also called "Europiep" or "Europiepser") is a wireless paging system designed by the postal and telecommunications administrations of the European states, which was originally used in the Federal Republic of Germany (1974), in France (1975) and in the Switzerland (1985) was introduced.

In the past, messages to Eurosignal receivers were sent over the telephone. A recipient could be assigned up to four radio call numbers. It contained one acoustic and four optical signals that indicated which of the phone numbers was being called. This made it possible to transmit up to four different signals per receiver. The meaning of the signals had to be agreed between the partners beforehand, as Eurosignal did not allow a direct transmission of a message. In order to rule out misuse, radio call numbers were generally not listed in telephone books.

In order to be able to transmit information to the Eurosignal subscriber, the caller first had to know in which paging area the desired subscriber is located. The FRG was in the three paging in 1989. North ( area code 0509), middle (area code 0279) and South divided (area code 0709). To do this, one dialed one of the three area codes and then one of the assigned phone numbers and was then, for example, heard the announcement “Eurosignal Mitte, Eurosignal Mitte” as soon as the system had recorded the message for the central radio paging area .

Some radio listeners might still remember the Euro signal, as the signal was responsible for the tone sequence audible at the lower end of the FM band. At the beginning (in contrast to VHF radio ) amplitude modulation was used. However, due to interference, the system later switched to frequency modulation . The following four internationally agreed radio channels have been assigned to Eurosignal:

• Channel A: 87.340 MHz
• Channel B: 87.365 MHz
• Channel C: 87.390 MHz
• Channel D: 87.415 MHz

In Germany channels A and B, in France all four and in Switzerland only channel D were used. The transmission network consisted of basic network transmitters with outputs of up to 2 kW as well as city and filling transmitters with outputs between 10  W and 100 W. All transmission systems had reserve transmitters, which took over the feed if the main transmitter failed.

There were special answering machines available which, after recording a telephone call, notified the absent participant via his "Europiepser". If the phone was not answered within an hour, the answering machine repeated the call to the EFuRD headquarters.

At the beginning, Eurosignal was used for police radio and since 1995 the car phone . At its time, Eurosignal had the advantage over the car phone in the German networks ( A , B or C ) that it was about 10 times cheaper and only needed a small receiver the size of a notebook. In addition, Eurosignal receivers were available wherever normal VHF radio reception was possible, including in remote areas and forests.

In France and Switzerland the transmission of the Eurosignal was stopped on December 31, 1997, in Germany on April 1, 1998.

Coding

Euro signal based on the transmission of audio frequencies, similar to the ZVEI - Selektivruftonfolgen , symbolized digits. In general, the code frequency of each digit of a phone number was sent for 100 ms.

The number 1 2 3 4 5 6 was transferred as f ₁ f ₂ f ₃ f ₄ f ₅ f ₆ .

If a digit should be repeated, a special repetition frequency f _{r was} sent instead of the digit identification frequency .

For example, the number 1 1 1 1 1 1 was transmitted as f ₁ f _r f ₁ f _r f ₁ f _r .

Two consecutive phone numbers were separated from each other by the frequency f _i for at least 220 ms, which is 820 ms transmission time for a six-digit phone number.

The frequencies used were:

meaning	notation	frequency
Digit 0	f 0	979.8 Hz
Section 1	f 1	903.1 Hz
Section 2	f 2	832.5 Hz
Section 3	f 3	767.4 Hz
Section 4	f 4	707.4 Hz
Section 5	f 5	652.0 Hz
Section 6	f 6	601.0 Hz
Section 7	f 7	554.0 Hz
Clause 8	f 8	510.7 Hz
Clause 9	f 9	470.8 Hz
Free	f i	1153.1 Hz
Repetition	for r	1062.9 Hz

Semafoon

The Dutch / Belgian Semafoon network was introduced in 1964 (Belgium: 1967) and at the time used a method very similar to the Eurosignal . The broadcasters Lopik and Smilde as well as two other broadcasters in Belgium also broadcast on four channels just below the VHF radio band, although to avoid mutual interference they rotated their broadcast frequencies among each other after each number broadcast. The dial-in number for the headquarters in The Hague was 065 from the Netherlands or 003165 from Belgium. A number was transmitted in approx. 700 ms.

Three receiver models were available:

• Escort as big as a small suitcase
• Minor , the size of a pocket book
• Piccolo , the size of a cigarette box

The first two models had three beacons labeled "1", "2" and "4". One or two lamps could be on at a time, so the binary display of the digits 1 to 6 was possible; Up to six phone numbers could be assigned to a recipient.

The Piccolo model had a seven-segment display .

Modacom / GfD

Remote data transmission (DFÜ) independent of lines was made possible by Modacom (= "Mobile Data Communication"), a cellular mobile radio service with handover and roaming . The information was transmitted by the participant via a radio modem to a Modacom base station and passed on from there via data lines to companies that were connected to the Datex-P network. After the start of regular operations, which took place on June 1, 1993, the operator DeTeMobil planned to guarantee a supply of around 80% of the German federal territory in the final stage. After nine years of operation, Modacom service was discontinued on July 1, 2002.

In competition with the Modacom network based on DataTAC, the GfD Gesellschaft für Datenfunk mbH operated a Mobitex network with similar functionality from January 1995 to September 1996.

Omniport

Was Omniport a paging service of Detex in Darmstadt , who had been in operation since 1994th The radio paging service used RDS and was therefore available everywhere in Germany where there was radio. Therefore there were no call zones. Operations ceased on December 31, 1997.

Scall

→ Main article : Scall

Scall was a paging service that was put into operation by DeTeMobil GmbH in Bonn in 1994. The last time the service was operated by eMessage , it was shut down for private customers on March 30, 2002. The specialty of Scall was the lack of monthly basic fees. The owner of a Scall receiver could be reached in his personal reception area - within a radius of around 50 km from his postcode. Scall could be used throughout Germany. The call was sent by dialing the area code 01681 plus the number. The service was financed by the calling party via the prefix tariff.

TeLMI

TeLMI was a paging service of the Deutsche Funkruf GmbH (DFR). The DFR is an association u. a. from Mannesmann , Motorola and Thyssen Telecom .

Numeric and alphanumeric data could be transmitted and messages could be left on a voicebox. Costs were incurred exclusively for the caller, but not for monthly basic fees, as is or was with the Scall service and many similar services.

The TelMI paging service was in operation from December 1995. Due to financial difficulties in the ensuing bankruptcy proceedings, the operation of the radio network was discontinued on January 3, 2002. Until early 1997, TeLMI was only available in metropolitan areas. TeLMI messages could not be received on motorways, and a comprehensive network was not planned.

Quix

→ Main article : Quix

Quix was a radio paging service from Miniruf GmbH from Hanover, which went into operation in Germany in 1995. A distinction was made between eight regions nationwide, national accessibility was also possible against payment of a monthly tariff. A special feature of Quix was the ability to receive agency reports from the German Press Agency (dpa) in the form of news headlines. The service was shut down on December 31, 2000 because the widespread use of cell phones made the system no longer financially viable.

Radio paging services in Austria

The pager service in Austria, also known as the “public paging service (ÖPR)” and charged at the local rate, was introduced in 1974 (other sources cite 1975) under the state post and telegraph administration .

The “pager”, also known colloquially as “beeper”, were carried with a clip on the belt or in the breast pocket or inside jacket pocket. Some devices were rather elongated, others almost square. In addition to a green light-emitting diode for “device in operation”, there was a second, red one that could signal a “call has been made”, possibly combined with a beep. By dialing a special telephone number in the fixed network , which was the only telephone network when the service was introduced, the call was triggered and delivered to the pager within a short time. Group calls have also been introduced in order to reach several pagers at the same time.

Service providers such as doctors or press photographers were called to work that suddenly occurred. If you were in a radio shadow for a while, the call was later delivered when the pager was available. After a pager call, the recipient could call back by phone if necessary.

In addition to the emerging mobile telephony, pager services were popular for a long time. This was due on the one hand to the lower prices compared to mobile tariffs, the light weight of the pager at around 100 grams and, last but not least, the availability even in places where the use of mobile phones is not permitted.

In July 1997 there were two other private pager providers on the market in addition to the pager service provided by Mobilkom Austria:

Mobilkom , more than 105,000 pager customers:

• Tariff “Mobilkom Classic” (ÖPR-I), area code 0666, basic fee per month: Tonpager 80  Schilling , number pager 150 Schilling, text pager 210 Schilling; Charging at the local tariff of Telekom Austria AG (TA) (at that time 40 schillings per hour or 0.67 schillings per minute).
• Tariff “Mobilkom Call Me” (ÖPR-II), area code 0669, without basic fee, billing with the 4th TA foreign zone.

AirPage , was estimated to have around 40,000 pager customers:

• Tariff “AirPage”, area code 0688, no basic fee, 1 message approx. 10 schillings, call charged with 3rd or 4th TA foreign zone

Paging-One , was estimated to have around 5,000 pager customers

• Tariff “Paging One Services”, area code?, Basic fee per month: number pager 170 Schilling, text pager 440 Schilling, charging at the local TA tariff.

A total of 150,000 “active pagers” were estimated in Austria in July 1997. As can be seen above, the receivers of this generation were already capable of alphanumeric data transmission. Often, however, only a callback number was transmitted, but also text messages which, depending on the device, could be considerably longer than SMS.

At the beginning of May 2000 there were still 15,000 pager connections registered with Mobilkom . The pager service was discontinued at the end of 2000 not only because of the “cell phone boom”, but ultimately also because of the lack of spare parts to maintain the necessary infrastructure. While limited operations were maintained for emergency call organizations such as the Red Cross, mountain and water rescue and fire services, operations were finally stopped at the end of September 2002.

At the beginning of 2006, work began on building a digital trunked radio network based on the TETRA standard, a planned tap-proof security radio network, at the Vienna police force. In the summer of the same year, the Viennese rescue service and in autumn the Viennese professional fire brigade were to be involved.

Despite this, and in spite of nationwide mobile networks, a “pager network” based on the POCSAG standard with 1,200 baud was set up again from March 2005 by the Austrian control center development, operating and integration company (LEBIG) (now Lower Austria emergency call ). This ensures a highly available alerting of security services in the federal states of Vienna, Lower Austria and partly Burgenland . At the beginning of 2006, the Red Cross, the Arbeiter-Samariter-Bund, the emergency doctor helicopters of the ÖAMTC, as well as the first responder doctors and executives were connected to this network. The fire brigades in Lower Austria have also been using the digital pager network since 2012. Another service based on the POCSAG standard was set up by the regional fire brigade association in Upper Austria . The TETRA and pager networks are used in parallel by the rescue organizations, with the alarm being sent via the pager, but the data being sent to the ambulance via TETRA. In autumn 2009 unauthorized persons gained access to the pager network operated by the state of Tyrol called WAS - warning and alarm system and put sensitive data that was sent unencrypted to the pager online.

Web links

• Pager FAQ: Radio paging services in Germany as of January 2, 1997 with operator, commissioning, radio protocol, access to sending messages, recipient, monthly. Charges (in D-Mark), call transmission, network coverage.
• World's largest pager collection on the Internet
• http://www.emessage.de Website from e * Message
• http://www.ecityruf.de Website e * Cityruf
• http://www.bos-alarmierung.de BOS alerting website
• http://www.etsi.org/deliver/etsi_ts/102100_102199/102182/01.04.01_60/ts_102182v010401p.pdf ETSI TS 102 182 (EmTel: Authorities to Citizens)
• http://www.etsi.org/deliver/etsi_tr/103100_103199/103102/01.01.01_60/tr_103102v010101p.pdf ETSI TR 103 102 V1.1.1 (2013-08)

Individual evidence

1. ^ City radio network for Leipzig. Short text of the article from May 25, 1990 in the archive overview
2. ^ Website e * Message / e * Cityruf
3. ↑ ERMES (European Radio Messaging Services). ( Memento of the original from April 11, 2011 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. . In: ITWissen - online magazine for information technology. Without a date. Retrieved October 24, 2010.  
4. ↑ ^{a b c d e} paging and trunked radio. ( Memento of the original from October 3, 2008 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Mobile Communication Forum , December 12, 2002. Accessed October 24, 2010.  
5. ↑ Website e * Cityruf Global ( Memento of the original from April 14, 2009 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  
6. ↑ Radio paging in amateur radio | The amateur radio | Activities | AKAFUNK. Retrieved January 16, 2018 . 
7. ↑ raspagerc9000 [DAPNET DokuWiki]. Retrieved January 16, 2018 . 
8. ↑ raspager [DAPNET DokuWiki]. Retrieved January 16, 2018 . 
9. ↑ 9k6 [DAPNET DokuWiki]. Retrieved January 16, 2018 . 
10. ↑ paging. Retrieved January 16, 2018 . 
11. ↑ Ralf, DH3WR: Radio Call Master 2.0 DAPNET - RWTH amateur radio group. (No longer available online.) Formerly in the original ; accessed on January 16, 2018 (German).  ( Page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.    
12. ↑ DAPNET - Decentralized Amateur Paging Network. Retrieved January 16, 2018 . 
13. ^ Federal Network Agency - Amateur Radio. Retrieved January 16, 2018 . 
14. ↑ Press releases from August 26, 2007 ( Memento of the original from November 21, 2007 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. on Presseportal.de  
15. ↑ Report on the bankruptcy of Dolphin Telecom GmbH on teltarif.de.
16. ↑ Sound sequence on savethesounds.info.
17. ↑ semaphonic (Dutch)
18. ↑ ^{a b c} Martin Weissenböck: Networks: Mysterious area code and telephone numbers. PCNWEWS edu , No. 51, February 1997, pp. 116-117. ( Online, PDF, 2 pages ).
19. ↑ ^{a b c d} 30 years of mobile communications in Austria. In: heise mobil , May 5, 2004. Retrieved October 24, 2010.
20. ↑ For example: Christian Wolf, Gerald Grünberger: The Austrian D-Netz: History of mobile radio in Austria. wolfsoft.net, undated (after October 2002). Retrieved October 24, 2010.
21. ↑ ^{a b c d} Michael Köttl / fak: Pager: Where cell phones are not allowed. In: Mobile Times, Issue 16, 1997. With a table of the “tariffs for pagers in Austria” provided by Mobilkom (two tariffs), AirPage and Paging One Services in 1997.
22. ↑ TETRA digital radio: data on deeds. On heise online, November 23, 2005. Accessed October 24, 2010.
23. ↑ Digital authority radio: Vienna police start TETRA network. On heise online, January 10, 2006. Retrieved October 24, 2010.
24. ↑ Comparison between Austria and the failed TETRA project. On heise online, October 20, 2006. Retrieved October 24, 2010.
25. ↑ FAQ on the TETRA radio network digital radio BOS Austria. ( Memento of the original from December 25, 2010 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. tetranetz.at from NOTRUF NÖ GMBH (www.144.at). Retrieved October 24, 2010.  
26. ↑ Digitalpaging SPS Austria: Milestones - From the idea to the realization. ( Memento of the original from October 29, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. pagernetz.at of NOTRUF NÖ GMBH (www.144.at). Retrieved October 24, 2010.  
27. ↑ The pagers are back in Austria. On heise online, January 17, 2006. Accessed October 24, 2010.
28. ↑ Austrian patient data ended up in the network. On heise online, September 8, 2009. Accessed October 24, 2010.