Method of establishing a radio link

The invention relates to a method for establishing a radio link between at least two Netznehmernehmem a digital relay radio network, wherein the individual network subscribers an individual location-dependent position identifier is assigned, so that the position of all network subscribers is determined relative to each other.

Methods of the type in question are known in the context of radio networks such as, for example, the mobile radio networks C, D1, D2 and E-plus network. The known networks for this purpose have stationary radio equipment in the form of relay stations. The establishment of a radio connection takes place by means of external switching methods in the context of an external radio network management. The localization of the network subscribers and the connection between the network subscribers takes place in these mobile networks by means of the central conciliation procedure.

When establishing a radio connection, the central relay stations play the fundamental role, as they stand by a division of the radio network area into individual network cells in constant mutual contact with the network subscribers. Thus, the respective relay station, the whereabouts of the network subscriber by its feedback at the relay station and then continue to be known at the network center always.

When establishing a radio connection between two network subscribers, the network subscribers are first located by means of the central switching process. Subsequently, the radio connection between the network subscribers is calculated or determined exactly and then switched on. The preliminary calculation or definition of the connection path via possible partial connections is called "routing".

The known methods act between the mobile devices and the stationary relay stations of the respective network cells of the known radio networks. In the known radio networks is therefore essential that external and centrally controlled process find application, which are essentially used by an external operator - eg. A central computer - outside the individual mobile devices or wireless terminals.

In known methods for establishing a radio link within the known radio networks is problematic that always stationary transmission relay or relay stations are required to establish a radio connection. It follows that in the establishment or reconstruction of a radio network of the known type always first a nationwide network of stationary relay stations must be established. Thus, the flexibility of a network system is greatly reduced in terms of a new implementation.

From DE-A-3 337 648 a method for producing a radio link according to the preamble of claim 1 is known. An individual location-dependent position identifier in the form of the addresses of the subscribers via an active determination is assigned as required to the individual network subscribers. This determines the position of all network nodes relative to each other. To establish a radio connection, each network subscriber in a table has information about at least two routes to each other network subscriber. The network subscriber selects these routes independently by optimizing the path lengths. In addition, the routes are adapted to the current positions of the network participants by periodically repeated surveys. If this adaptation is too slow or if the network subscribers change their positions very quickly, the establishment of a radio connection may take place via obsolete routes or is not possible at all.

The present invention is therefore based on the object to provide an alternative, simplified method for establishing a radio link between at least two network subscribers of a digital relay radio network, which flexibly adapts to the respective changed network constellation.

According to the invention the above object is achieved by a method having the features of claim 1. Thereafter, the method in question is designed such that a successive comparison and decision process is performed until the establishment of the radio link.

Due to the relatively fixed position identifier, the establishment of a radio link is made possible step by step from network subscriber to network subscriber. The provision of separate stationary relay stations is no longer necessary. To establish a radio connection, a source subscriber only needs to know its own position identifier and the position identifier of the destination user. The wireless connection is then established via further network subscribers present between the source subscriber and the destination subscriber, who, on the basis of the knowledge of their own position identifier, can forward a radio signal emitted by the source subscriber in a targeted manner to the destination subscriber.

A relay radio network in which the inventive method could find its application is known from the post-published German patent application DE-A-1 953 5021. Therein, a relay radio network is described, which consists of individual mobile devices that serve both as a terminal and as a relay. As a result of the assignment of a position identifier according to the invention, the network subscribers in the known relay radio network can be addressed in a location-dependent and direction-dependent manner and directed in a targeted manner. directionally connected.

In the invention, the localization of the network subscriber and the determination of the radio path between the network subscribers are not performed exactly by means of stationary relay stations and fixed radio network cells. The direction of the radio path to the desired destination subscriber is given directionally in the radio connection setup via the stepwise definition of the successive sub-radio paths via other network subscribers. During the construction or the connection of the radio link, the radio link is not yet determined until the determination of the last part radio path. As a result, it is possible that several sub-radio paths may be selected at the same time and multipath propagation or the establishment of several parallel radio links take place.

Consequently, the method according to the invention specifies a method for producing a radio connection, in which it is possible to establish a radio connection in a simple manner even in a network without stationary relay stations.

With regard to a simple radio link setup, it is advantageous if the network subscribers involved in establishing a radio link know their position code for comparison with the position code of other network subscribers. For this purpose, the position identifier assigned to a network subscriber could be stored by the respective network subscriber.

With regard to a particularly simple assignment of position identifiers, the position could be determined relative to radio signals emitting radio signal transmitters with a predeterminable location. For this purpose, at least three radio signal transmitters could be provided. The radio signal transmitters could then transmit the radio signals at certain times or at certain intervals. By receiving the radio signals from the predeterminable locations, the position of the receiving network subscriber can be determined in a simple manner relative to the radio signal transmitters. This allows a clear position determination and a clear assignment of a position identifier.

A particularly secure assignment of location-dependent position identifiers could be realized if the radio signal transmitters are distributed over the radio network area at the edge of the radio network area. The radio signal transmitters must not span any collinear axis systems.

With regard to a secure transmission or to a secure reception of the radio signals, the network subscribers could receive the radio signals transmitted directly from the radio signal transmitters or via other network subscribers. In other words, all network subscribers also serve as transmitters of the radio signals for the assignment of a position identifier. In this case, the radio signals of the radio signal transmitter could be transmitted by the serving as a transmitter network subscribers avalanche.

With regard to a particularly clear differentiation of the radio signals from different radio signal transmitters, the radio signals of the radio signal transmitter could be forwarded in the onward transmission with a transmitter-dependent or predeterminable delay time. Thus, the resolution of received radio signals from spatially closely adjacent, but via different network subscribers transmitting radio signal transmitters could be significantly improved.

The radio signal transmitters could transmit radio signals at certain time intervals, possibly monthly or even at significantly shorter intervals. The radio signals could be time synchronization signals which are relayed by all transmitters in the relay radio network. Such avalanche-like forwarding could take place according to the radio acceptance procedure without memory switching, which is described in the subsequently published German patent application DE-A-19 608 846. Each radio signal transmitter transmits individually and all radio signal transmitters transmit successively, for example at a specific programmed time or after a certain time interval.

The radio signals of the radio signal transmitter could experience location-dependent and / or direction-dependent manipulations of their information content in the further transmission in the radio network area with regard to a particularly good distinguishability of the origin of the radio signals. In addition to better distinguishability with regard to the origin of the radio signals, a particularly distinctive position identifier can then also be assigned. Such manipulation could include a propagation delay.

With regard to an exchange of information between the transmitters, the radio signals of the radio signal transmitters could transmit further information of the network subscribers serving as transmitters during the transmission by the network subscribers.

With regard to a particularly clear differentiation of the radio signals of different radio signal transmitters, the radio signals of the different radio signal transmitters could be physically differentiated by the network subscribers with respect to a different radio frequency and / or a different logical coding and / or a different information content and / or a different time duration and / or a different transmission order become. It is fundamentally essential that the network subscribers can clearly determine from which radio signal transmitter the respective received radio signal originates.

Each transmitter which receives radio signals from different radio signal transmitters in a certain chronological order thus receives a signal sequence dependent on the location of the receiver. From the time intervals of the incoming radio signals, the location of the recipient is uniquely determined. The position identifiers assigned to the network participants develop locally and directionally within the network area because of the relay delays.

In the presence of, for example, three wireless signal transmitters, the radio signal of the first radio signal transmitter after 1 sec. Considering relay delays could arrive at the respective network participants, the radio signal of the second radio signal generator after 3 sec and the radio signal of the third radio signal transmitter after 5 sec Create position identifier 1-3-5.

Another possibility of generating a position identifier could be derived by increasing a count or count argument within the radio signal, depending on the number of transmissions. In other words, a numerical value is increased by, for example, 1 each time the respective radio signal is transmitted. In the presence of, for example, three wireless signal transmitters could then consist of a position identifier from the respective number of transmissions of the respective radio signal as follows. Has eg. If the first radio signal has passed three transmissions, the second radio signal ten transmissions, and the third radio signal twenty transmissions, a position identifier 3-10-20 would be conceivable. Thus, the radio signals of the radio signal transmitter in the retransmission in the radio network area, a location-dependent and / or direction-dependent change of Zählargumenten containing the radio signals, learn by a further counting by the respective transmitter. In other words, a location-dependent and direction-dependent differentiation of the position sequences is achieved, wherein each transmitter chronologically counts or counts in the transmission of a step number and this changes or adds as an information component in the encoder signal. Due to the counted number of steps, these position identifiers develop in a location-dependent and direction-dependent manner over the network area.

A third possibility of position identification could be achieved if the radio signal transmitters consist of satellites of the Ground Positioning System (GPS). The network participants receive their absolute geographical position as signals. This consists of the parameters latitude and longitude. The position identifier could then consist only of the geographical position data obtained via the GPS.

In order to realize the position identification by means of the GPS, the device hardware has to be more elaborate than for the reception of the radio signal transmitters arranged in the network. However, this system eliminates the avalanche-like structure of the position detection system and thus relieved the network considerably. The application of the GPS to localize the network subscribers provides a high spatial resolution, which would also a secure location of the network subscriber in emergencies for the benefit of auxiliary services, rescue services, etc. would be possible. A direct guidance of such auxiliary services to the whereabouts of the network subscriber would thereby be possible in a simple manner.

The position identifier could advantageously - comparable to a postal code - consist of a string and / or sequence of numbers, which can be derived directly from the position sequence or from the time sequence of the arrival of the radio signals from different Funkksignalgebem. In this case, the number sequence of the position identifier could consist of the numerical values ​​of the time differences of the different radio signals of the radio signal transmitters relative to one another or relative to a specific reference signal of the radio signals on receipt by the network subscribers.

As an alternative, the number sequence of the position identifier could - as already described - consist of the numerical values ​​of the counting arguments, in particular of the step numbers in the onward transmission of the different radio signals of the radio signal transmitters. In a further alternative, the sequence of numbers of the position identifier could consist of the numerical values ​​of geographical position data, in particular the latitude and longitude received by the network subscribers. These position identifiers could be assigned to the network subscribers at the place of their reception as addresses in the radio network area. Thus, the position identifiers could form a location-dependent and direction-dependent position identification system. When recording the radio connection or when establishing the radio connection, the network subscribers could address the desired destination subscriber with these position identifiers or addresses.

For establishing the radio link, it is essential that the network subscribers know their own position code as well as the position identifiers of the source subscriber and the destination subscriber. Then, a network subscriber addressed during the radio connection setup between a source subscriber and a destination subscriber and acting as a transmitter could display his position identifier, the position identifier of the destination user and the position identifier of the source subscriber or, if appropriate, Compare the previous transmitter and then decide whether he carries out a retransmission. In other words, an addressed network subscriber or transmitter compares the destination user identifier, the source transmitter identifier and its own identifier with each other. The transmitter checks whether its own position identifier is more similar to the destination subscriber identifier than the position identifier of the source transmitter. If this is the case, he will continue to transmit , in the other case, the transmission through him will not continue. In the case of its further transmission, the transmitter is closer to the destination subscriber than its source transmitter. Further transmission by the transmitter is no longer useful if it is further away from the destination subscriber than the respective source transmitter. In the latter case, the source transmitter itself transmits further. By this principle, the desired radio connection can be produced successively.

The comparison and / or decision method could be based on a similarity comparison of the position identifiers, in particular a fuzzy-logical decision-making method.

In order to generate alternative connection paths and thus a particularly secure connection preparation, multipath propagation could be generated when the radio connection is switched on.

In the case of using the GPS for the assignment of a position identifier to the network subscribers, the position identifier could, for example, consist of the geographical latitude and longitude. This geographical position data or another type of position identifier could be transmitted automatically when connecting the radio link from the source subscriber to the destination subscriber. This would be an automatic information of auxiliary and / or rescue facilities such as. the ADAC (General German Automobile Club) feasible. This would allow a simplified finding of the source participant, for example. In an emergency situation in which the source participant either does not know its exact position or can not transmit properly due to great excitement or health impairment. Such automatic position determination when recording a radio connection could also be provided in known radio network systems. This could, for example, be realized by implementing a GPS chip in a conventional mobile phone.

The application of the method according to the invention for establishing a radio connection could also take place in conventional mobile radio networks of the abovementioned type, wherein it would be possible to dispense with the provision of stationary relay stations given a corresponding position identification of the network subscriber. This would no longer require central network administration.

In the following an embodiment of a possible method for the similarity comparison is described, which must be performed by an addressed transmitter to decide whether the radio link should continue to be built on him or whether it is cheaper to break the connection establishment with him:

First, the source subscriber transmits its radio call for connection to the required paging parameters A to its transmitter environment of its transmission / reception range or contraction range. The parameters A contain the position sequence or position identifier A as a part of the source identifier A2_2Q: (q₁, ..., q_n) and as a proportion of the destination subscriber identifier A1, the position identifier A1: (z₁, ... z_n). These position sequences or position identifications consist of the time interval sequence or the step number sequence or the sequence of geographical parameters or position data of the ground-based or satellite-based signal generator. The destination subscriber identifier A1 is known to the user or the source subscriber from a type of telephone book with all position identifiers of the destination subscriber. Such a telephone book may be in the form of electronic storage at the source subscriber. The update of the telephone book occurs after each assignment procedure of the position identifier. This assignment process can take place daily, hourly or at even shorter intervals. By way of example, the method is intended to be continued only by means of the step number parameters q_n and Z_n be explained. However, it can be applied identically to the types of position identifiers already mentioned. The particular application used can be tested for technical or economic aspects.

The addressed reachable transmitters now compare each position z_n the destination subscriber code or identifier A₁ with the corresponding position q_Zn the own position identifier A_2Z and with the corresponding position q_Qn the position identifier A_2Q the source subscriber or previous transmitter. For this purpose, the arithmetic step number difference sequences D_{A1, A2Z}, D_{A1, A2Q} between the step number sequences A₁ and A_2Z, A_2Q educated.<maths id="math0001" num=""><math display="block"><mrow><msub><mrow><mtext>D</mtext></mrow><mrow><mtext>A1, A2Z</mtext></mrow></msub><msub><mrow><mtext>: (d</mtext></mrow><mrow><mtext>n</mtext></mrow></msub><msup><mrow><mtext>​</mtext></mrow><mrow><mtext>A1, A2Z</mtext></mrow></msup><msub><mrow><mtext>) = D</mtext></mrow><mrow><mtext>A1, A2Z</mtext></mrow></msub><msub><mrow><mtext>:</mtext></mrow><mrow><mtext>1</mtext></mrow></msub><msub><mrow><mtext> - q</mtext></mrow><mrow><mtext>Z1</mtext></mrow></msub><msub><mrow><mtext>, ..., z</mtext></mrow><mrow><mtext>n</mtext></mrow></msub><msub><mrow><mtext> - q</mtext></mrow><mrow><mtext>Zn</mtext></mrow></msub><mtext>)</mtext></mrow></math><img file="EP0908026B1_D0001.tif" /></maths><maths id="math0002" num=""><math display="block"><mrow><msub><mrow><mtext>D</mtext></mrow><mrow><mtext>A1, A2Q</mtext></mrow></msub><msub><mrow><mtext>: (d</mtext></mrow><mrow><mtext>n</mtext></mrow></msub><msup><mrow><mtext>​</mtext></mrow><mrow><mtext>A1, A2Q</mtext></mrow></msup><msub><mrow><mtext>) = D</mtext></mrow><mrow><mtext>A1, A2Q</mtext></mrow></msub><msub><mrow><mtext>:</mtext></mrow><mrow><mtext>1</mtext></mrow></msub><msub><mrow><mtext> - q</mtext></mrow><mrow><mtext>Q1</mtext></mrow></msub><msub><mrow><mtext>, ..., z</mtext></mrow><mrow><mtext>n</mtext></mrow></msub><msub><mrow><mtext> - q</mtext></mrow><mrow><mtext>Qn</mtext></mrow></msub><mtext>)</mtext></mrow></math><img file="EP0908026B1_D0002.tif" /></maths>

The differences d_n are mapped by the function F and the images F (i.e._n) are summed in S.<maths id="math0003" num=""><math display="block"><mrow><msub><mrow><mtext>F (d</mtext></mrow><mrow><mtext>n</mtext></mrow></msub><msub><mrow><mtext>) = 1 for amount (i.e.</mtext></mrow><mrow><mtext>n</mtext></mrow></msub><msup><mrow><mtext>​</mtext></mrow><mrow><mtext>A1, A2Z</mtext></mrow></msup><msub><mrow><mtext>) &lt;Amount (i.e.</mtext></mrow><mrow><mtext>n</mtext></mrow></msub><msup><mrow><mtext>​</mtext></mrow><mrow><mtext>A1, A2Q</mtext></mrow></msup><mtext>)</mtext></mrow></math><img file="EP0908026B1_D0003.tif" /></maths><maths id="math0004" num=""><math display="block"><mrow><msub><mrow><mtext>F (d</mtext></mrow><mrow><mtext>n</mtext></mrow></msub><msub><mrow><mtext>) = 0 for amount (i.e.</mtext></mrow><mrow><mtext>n</mtext></mrow></msub><msup><mrow><mtext>​</mtext></mrow><mrow><mtext>A1, A2Z</mtext></mrow></msup><msub><mrow><mtext>) = Amount (i.e.</mtext></mrow><mrow><mtext>n</mtext></mrow></msub><msup><mrow><mtext>​</mtext></mrow><mrow><mtext>A1, A2Q</mtext></mrow></msup><mtext>)</mtext></mrow></math><img file="EP0908026B1_D0004.tif" /></maths><maths id="math0005" num=""><math display="block"><mrow><msub><mrow><mtext>F (d</mtext></mrow><mrow><mtext>n</mtext></mrow></msub><msub><mrow><mtext>) = - 1 for amount (i.e.</mtext></mrow><mrow><mtext>n</mtext></mrow></msub><msup><mrow><mtext>​</mtext></mrow><mrow><mtext>A1, A2Z</mtext></mrow></msup><msub><mrow><mtext>)&gt; Amount (ie</mtext></mrow><mrow><mtext>n</mtext></mrow></msub><msup><mrow><mtext>​</mtext></mrow><mrow><mtext>A1, A2Q</mtext></mrow></msup><mtext>)</mtext></mrow></math><img file="EP0908026B1_D0005.tif" /></maths>

The sum S of the function values ​​F (i.e._n) of the difference sequences of the step number differences<maths id="math0006" num=""><math display="block"><mrow><msub><mrow><mtext>S = sum</mtext></mrow><mrow><mtext>n = 0 to n = s</mtext></mrow></msub><msub><mrow><mtext> (F (d</mtext></mrow><mrow><mtext>n</mtext></mrow></msub><mtext>))</mtext></mrow></math><img file="EP0908026B1_D0006.tif" /></maths> then gives the measure for the decision of a transmitter to pass on the radio call of the source participant. The summation limit s is the number of radio signal transmitters used in the network area. In the case of a positive measure S, a transmitter will, in principle, be able to pass on the radio call and S will not be able to do so with a neutral or negative measure. If the transmitters return their result from the position matching comparison to the respective source - source subscriber or previous transmitter - the source subscriber or the previous transmitter can select the transmitter as far as possible and select it specifically for transmitting the radio call in the context of a one-way propagation. If, in each case, the achievable transmitter with the greatest degree of decision in the transmission is selected, a particularly purposeful spatial connection is established, without the existence of multipath propagation.

By this radio communication method avalanche-like radio contact recording can be avoided. The radio contact recording takes place rather spatially targeted. Depending on the decision-making process, it can be designed as multipath propagation or targeted one-way propagation. In this radio communication method, only the position identifier of the destination subscriber must be known to the source subscriber.

The position identifier of a destination subscriber is renewed or changed again after a renewed radio signaler action and transmitted to the transmitters and the source subscriber in an already switched-on radio connection.

In the method according to the invention, the addressing in a relay radio network can be composed of a network subscriber-specific addressing component and a location-specific addressing component.

The invention also supports existing radio links to mobile and mobile subscribers. If the moving network subscriber is reached in an initial radio contact, it is located at the same time, because a position identifier is transmitted by protocol in the radio communication. This allows the network subscribers to calculate the developments of the position identifiers or to extrapolate and direct the radio link to the next locality of the destination subscriber by the position identifier addressing.

The problem of the movement of network subscribers and thus possibly required correction of the radio link can be avoided so that the network subscriber has a telecommunications device, which consists of a stationary relay and a mobile terminal. In this case, the relay could be provided with the position identifier and individually close the radio connection path to the terminal despite movement of the terminal. Thus, the relay would always be available as a stationary point of contact for radio communications in the sense of a home relay.

Finally, it should be emphasized that the previously purely arbitrary chosen embodiments of assigning a position identifier only serve to discuss the teaching of the invention, but not limit these to these embodiments.