2 Public Safety and Security Network in Germany

Article 44 of Schengen Treaty from June 19th, 1990 declares that a uniform radio network for speech and data transmission has to be used in Europe since the borders between European countries will be opened. (cf. BMI010726)

2.1 Germany needs a Digital Public Safety and Security Network

The Conference of the Ministers of the Interiors decided on November 23rd and 24th, 2000 that the authorities and organizations with special security tasks do need an uniform digital radio network in Germany. From 2006 on, the police is supposed to use it not only because of the soccer world cup in Germany. The conference founded a project group named ZED. The ZED talked with potential suppliers in order to get to know the costs, operator model, the technique and requirements of the users. (cf. BMI001123)

2.2 Interest Procedure

In December of 2001 the Department of Procurement of the Federal Ministry of Interior started an interest procedure that ended in March 2002. The purpose of this interest procedure was to verify the offers of private suppliers in contrast to a solely federal solution. (cf. IBVAufruf) (cf. EmessageIBV)

2.3 Requirements

The GAN has defined several requirements:

2.3.1 Main Requirements

Radio Coverage The complete area of Germany including twelve nautical miles at the coast has to be covered. Near the borders, the neighboring countries should also be covered but the dose of radiation must comply agreed limits. Portal devices must have coverage in urban and suburban areas, the complete area has to be covered that devices in vehicles have radio reception. The coverage must be extensible in order to get in-house coverage as well and radio must work within tunnels. Air vehicles with a height up to 3,000 meters with common velocity should also be connected to the digital network. (cf. GAN02, p. 11 pp)

Cell Change Hand-overs from one base station to another must be done within 0.5 seconds, the call should not be stopped. (cf. GAN02, p. 13)

Capacity In urban and suburban areas a base station must provide fifteen channels. In rural areas only seven channels are required. Increasing the capacity must be possible easily for temporal limited purpose by mobile base stations. (cf. GAN02, p. 14)

Quality of speech Basically, every word must be understandable (100 %), but at least 96 % of the syllables according to DIN 45621. (cf. GAN02, p. 15)

Preemption The network must avoid two senders at the same time. If there is a call that has a bigger priority than the current one, it is terminated and the new one is taken. (cf. GAN02, p. 16)

Connection of headquarters Headquarters administer the radio network. The radio network has uniform and published interfaces with the following functionalities:

(cf. GAN02, p. 17 pp)

Quality of Service Security of the base stations must be appropriate and the availability must be 99 % in a year, that is to say that the network may be unaccessible for 0.01*365.25 = 3.65 days/year. (cf. GAN02, p. 19) But 3.65 days a year is quite a long time for such an important system. It must be considered to raise the rate up to 99.9 % or even higher.

Addresses 2 Million addresses must be available: single addresses, group addresses, headquarters addresses, gateway addresses.
A translation between a well remindable alphanumeric name, that can easily remembered, of the single device or a group and the real addresses is required. The name should contain 24 characters. (cf. GAN02, p. 20 pp)

2.3.2 Services

Group Calls A user should be a member of one or several groups and he or she should start group calls within 0.5 seconds (PTT). This fast call setup time is a very important feature since the users should contact their fellows very fast. Image a bank robbery: The group call has to be set up by a policeman during a persecution by car. The cars have great velocities and within few seconds the robbers may gain a lead over their pursuers, move many meters and escape. Thus, the policemen could have an advantage if the robbers used GSM cellphones and had a longer call setup time than the policemen.
Within PSS networks, about 80 % of the calls are groups calls. The headquarter and the other members of this group call should be able to receive it in each cell of Germany. If a user has not received a group call during its initialization, he or she should be added to this call (late entry). (cf. GAN02, p. 22)

Direct Calls Direct calls from one user to another should work within the radio network through addresses and from the radio network to the public telephone network. (cf. GAN02, p. 23)

Telephone Calls Telephone calls into the telephone network indicated by a special preselection are not mentioned by the GAN but are also very important.

Emergency Call Emergency calls should have a greater priority than normal calls. If a device receives an emergency call during a normal call, it must display it optically and signal it acoustically and the alphanumeric name of the sender must be displayed. This call must be entered without pressing a button. In the headquarter, the emergency call must also be shown optically and acoustically until it is manually affirmed. Only the headquarter and a special end user with special rights can terminate this call. (cf. GAN02, p. 24)

Encryption Radio encryption is not available in the current analogue radio. Mostly the signaling information is encrypted in the AIE and decrypted in the base stations and therefore accessible by man in the middle attacks. Additionally, an end-to-end encryption must be used so that the speech and data are only decrypted in the end user devices. There must be a mechanism in order not to activate the pagers without the appropriate access. (cf. GAN02, p. 25)
A PKI based on public and secret keys can be used for encryption and authentification as in OpenPGP application like PGP and GnuPG.

Data Transmission Data (e.g. telegrams or orders) must be transmitted with a rate of at least 4.8 kbit/s using low error correction. Data transmission does not disturb speech transmission. (cf. GAN02, p. 26)

Alarming Mostly, alarming is used by non-police organizations like fire brigades for sirens and pagers. The network must support active and passive devices and each Federal State can decide which one to choose. Passive alarming means that the end user devices can only receive the message and not send messages. Active alarming also allows to send messages using these devices. Due to its few functionalities the devices for passive alarming can be produced cheaper. This could decrease costs for that group of mostly voluntary users like fire brigades and the governmental disaster relief organization THW.
Alarming should be possible fora single person or for a group: A headquarter must be able to send alarming to 200 groups with 10 pagers in each group within 15 minutes and to a special area. The data to be transmitted should be at least 256 bytes. The alarming must be automatically confirmed by the end user device and maybe a manual confirmation. (cf. GAN02, p. 27)

2.3.3 Gateways to other networks

Gateways to other radio networks with the same technique The radio network in Germany is to be uniform with one operator that administers the network. The terminals work as well in neighboring countries. Single and group calls and data transmissions work in each combination from the home to the neighboring country. (cf. GAN02, p. 29)

Gateways to other radio networks with a different technique Due to the fact that there already are digital radio networks in Europe with different techniques, gateways to these are of major importance. Using the phone network in order to switch one network to another network can be done either automatically or manually. (cf. GAN02, p. 30)

Gateways to public telephone networks The radio network functions like a private branch exchange: The terminals can call numbers in the telephone network and vice versa, including conferences. (cf. GAN02, p. 31 pp)

Gateway to data networks The digital radio network should support data transmission without any additional hardware. (cf. GAN02, p. 33) Applications are searches for special persons or vehicles, special information on vehicle owners: WAP browsers that have been implemented into the radio devices (client) can access a database (server). Such a server providing WML pages is easy to use since existing infrastructure like the Apache Webserver and existing backend databases can be put to a further use and only a frontend in WML has to developed.

Gateways between analogue and digital networks During the migration from analogue to digital network, a group call should be possible by means of a connection between the headquarters. (cf. GAN02, p. 34)

2.3.4 Organizational Requirements

Uniform network The air interface, the technique, cryptography and the functionality should be uniform in Germany. Thus, users can use the network in the whole of Germany and work together. The planning and executions should be carried out by a central authority. Due to this standard, the devices will become cheaper because of the required number and fewer problems will occur. (cf. GAN02, p. 35 pp)

Independent Network The digital network should only be used for the purposes of the public safety organizations. Nevertheless, infrastructure can be reused but the capacity may not be shared. The network should not be affected by any user (e.g. a consumer in a commercial GSM network). But if this happens, there can be accusations for damages by both the PSS users and the consumers. (cf. GAN02, p. 37)

Organization The central operator is responsible for the administration of the network. If the Federation and the Federal States do not own more the 50 % of the operator, they found an authority that controls the operator.
Minimizing the cost is most important. The tasks concerning the headquarters and the procurement of the terminal devices are to be executed by the authority. (cf. GAN02, p. 38 pp)

Property and Legal Form of the Carrier The operator must be a legal entity and must not be part of another enterprise. The Federation and the Federal States can be (part) owner of the operator. If they are not, there should be the possibility to become (part) owner.
If the operator busts, the network infrastructure becomes property of the Federation or another authority (echeatage/"Heimfallregelung"). (cf. GAN02, p. 39)

Controlling The Federation and the Federal States (or another authority) must control the network in order to provide the security. They control the compliance of the service and the provision. They revise if the network has to be expanded and the resulting costs. (cf. GAN02, p. 40)

Frequencies The frequency band from 380 MHz - 400 MHz can be used for free but by all the network users. An authority ensures the accessibility, that is to say the frequencies are not to be blanketed. (cf. GAN02, p. 41) This frequency band was used by the NATO until 1992. The NATO agreed in 1993 to free this band for only PSS needs for TETRA. (cf. Beckkers01, p. 391)

Decentral Management by Users Each organization that uses the digital radio network can grant and revoke the access rights for special terminals (e.g. a terminal has been stolen). The headquarter can adjust the rights for single and group calls already mentioned above. (cf. GAN02, p. 42 pp)

2.4 Tender

On December 18th, 2003 the Ministers of the Interior of the Federation and the Federal States signed an agreement to use a uniform digital radio network. For the preparation of the tender that is going to be started in the end of 2004 (cf. Heise040528) a project organization which contains four groups has been founded by the BMI:

2.5 Financing

Germany is a federative state with the Federation and the Federal States. These (and the townships) share the public tasks and the costs. Each Federal States finances the police forces and the Federation finances the Federal Border Guard whose working place is not only the border but also the stations and airports. Both must work together, this is one of the requirements stated by the GAN: There should be a uniform network in Germany and they decided to do so finally. But Federal States and the Federation are discordant about the cost sharing. (cf. Hausmann04), (cf. Xdial031219)