Method for topology determination in a mobile communications site, a computer program, a computer program product and a corresponding mobile communications site

Abstract

Method for topology determination in a mobile communications site, wherein the mobile communications site has n nodes each having m ports. In determining (S.sub.1), the number of existing nodes is determined. In designating, one of these nodes is designated as the master node and the others as slave nodes. In selecting, a slave node is selected as a test slave node and the communication of the other slave nodes is prevented. In testing, a test is performed to determine via which ports of the master node and via which ports of the test slave node a communication is possible. Thereafter, selecting and testing are repeated for the other slave nodes, wherein in the method step selecting, a different slave node is selected as the test slave node in each case. In the method step generating, a connection topology is then generated for the master node.

Claims

1. A method for topology determination in a mobile communications site comprising n nodes, where n3, wherein each node has m ports, where m1 and every node is an electrical functional unit; and wherein each one of the n nodes is connected electrically and/or electromagnetically via at least one of its m ports to at least one other of the n nodes via at least one of its m ports for communications purposes, the method comprising: determining the number n of existing nodes; designating from the determined n nodes a master node and first and second slave nodes; selecting the first slave node as a first test slave node and preventing a communication of the other slave node(s); testing via which of the m ports of the master node and via which of the m ports of the first test slave node a communication between the master node and the first test slave node is possible, and storing these ports; selecting the second slave node as a second test slave node, and preventing a communication of the other slave node(s); testing via which of the m ports of the master node and via which of the m ports of the second test slave node a communication between the master node and the second test slave node is possible, and storing these ports; repeating the selecting and testing for each of the other slave nodes, if any, wherein in selecting, a different slave node is selected in each case as the test slave node; and generating a connection topology for the master node based on the stored ports.

2. The method according to claim 1, wherein in the selecting, the communication of the other slave nodes is prevented only for a predetermined duration of time or until a trigger signal occurs.

3. The method according to claim 1, wherein: the testing comprises: determining whether a communications link to the first test slave node can be created by an exclusive communication via only one of the m ports of the master node and storing this one port for the master node in the event that a communications link can be created; and repeating the determining until an attempt was made to create a communications link to the first test slave node for all m ports of the master node.

4. The method according to claim 3, wherein: the determining also comprises: preventing communication on all except one port of the first test slave node and storing this one port for the first test slave node, if a communications link can be created to the master node via this port; and repeating the preventing until an attempt was made to create a communications link to the master node for all other m1 ports of the first test slave node.

5. The method according to claim 3, further including: determining a port on the master node for communicating with the first test slave node and preventing communication on the other ports of the master node; preventing a communication to all but one port of the first test slave node and storing this one port for the first test slave node, if a communications link to the master node can be created via said port; repeating the preventing until an attempt has been made to create a communications link to the master node for all other m1 ports of the first test slave node.

6. The method according to claim 5, further including: executing again the establishing and preventing and repeating the preventing for all other ports of the master node for which it was determined in the determining that a communications link to the first test slave node can be created.

7. The method according to claim 1, wherein in the selecting, communication of the other slave nodes is prevented by an interruption in layer 1 or a higher layer at the respective m port of the other slave nodes; and/or in the preventing, preventing communication occurs: f) at the ports of the first test slave node; and/or g) the other ports of the master node; by an interruption in layer 1 or a higher layer at the respective m ports.

8. The method according to claim 1, wherein the n nodes comprise at least two different types of electrical functional units from the group of: base stations; combiners; DTMAs; RET units; antenna arrangements; monitoring units.

9. A method for topology determination in a mobile communications site comprising n nodes, where n2, or n3, or n4, wherein each node has m ports, where m1 and every node is an electrical functional unit, wherein each one of the n nodes is connected electrically and/or electromagnetically via at least one of its m ports to at least one other of the n nodes via at least one of its m ports for communications purposes, the method comprising: determining the number of existing nodes; designating from one of the determined n nodes a master node and the other node as the slave node; selecting a slave node as a test slave node and preventing a communication of the other slave nodes; testing via which of the m ports of the master node and via which of the m ports of the test slave node a communication between the master node and the test slave node is possible, and storing these ports; repeating the selecting and testing for each of the other slave nodes, wherein in selecting a different slave node is selected in each case as the test slave node; and generating a connection topology for the master node, and the method further including: repeatedly executing: a) designating; b) selecting; c) testing; d) repeating; and e) generating; wherein in the designating, one of the previously designated slave nodes is designated as the new master node, and wherein repeating the execution is executed until at least n1 nodes have been designated once as the master node.

10. The method according to claim 9, wherein at least one of the n nodes in addition to the m ports also has at least one additional wired or wireless interface and is designed to communicate via this at least one additional interface with other networks or devices, and further including: adding the at least one additional interface to the connection topology for the at least one of the n nodes.

11. The method according to claim 9, further including: creating a topology of the mobile communications site using the connection topologies generated in the generating, of the individual nodes, wherein the topology of the mobile communications site indicates to which additional node or which additional nodes each node is connected, for exchanging data.

12. The method according to claim 11, wherein: in generating a topology, the connection topologies of the individual nodes are transmitted to a node or to a control device, wherein the node or the control device generates the topology of the mobile communications site from the individual connection topologies.

13. The method according to claim 11, further including: comparing the generated topology with a reference topology; and determining and/or outputting deviations between the generated topology and the reference topology.

14. The method according to claim 12, wherein the mobile communications site also has a communications device, which is designed to transmit data to a higher-level routing and control device, and the method further including: transmitting the generated topology of the mobile communications site to the higher-level routing and control device; and/or transmitting the determined deviations between the generated topology and the reference topology to the higher-level routing and control device.

15. The method according to claim 1, wherein: in the determining, an individual rank is assigned to each of the determined nodes; and in the designating, the node whose rank has the lowest or highest value compared to the ranks of the other nodes, is designated as the master node.

16. The method according to claim 15, wherein the rank of a node stems from: a serial number; a device type; a number of ports; a MAC address; an IP address; an address; a number; an arbitrary number; a device feature; and/or a temperature value; or a feature derived from these.

17. The method according to claim 9, wherein: in the repeated execution, when executing the determining, the already allocated ranks are retained or the previous slave nodes are assigned entirely or partially new ranks.

18. A computer program for use in a mobile communications site comprising n nodes, where n3, wherein each node has m ports, where m1 and every node is an electrical functional unit; and wherein each one of the n nodes is connected electrically and/or electromagnetically via at least one of its m ports to at least one other of the n nodes via at least one of its m ports for communications purposes, the computer program comprised a non-transitory storage medium comprising program code instructions of the computer program that, when the program code instructions are executed on a computer or a digital signal processor, control the computer or the digital signal processor to perform the following operations: determine the number n of existing nodes; designate from the determined n nodes a master node and first and second slave nodes; select the first slave node as a first test slave node and prevent a communication of the other slave node(s); test via which of the m ports of the master node and via which of the m ports of the first test slave node a communication between the master node and the first test slave node is possible, and store these ports; select the second slave node as a second test slave node, and prevent a communication of the other slave node(s); test via which of the m ports of the master node and via which of the m ports of the second test slave node a communication between the master node and the second test slave node is possible, and store these ports; repeat the select and test for each of other slave nodes, if any, wherein in selecting a different slave node is selected in each case as the test slave node; and generate a connection topology for the master node based on the stored ports.

19. A computer program product with program code stored on a non-transitory machine-readable medium so as to perform all steps according to claim 1, when the program is executed on a computer or a digital signal processor.

20. A mobile communications site comprising: n nodes, where n3, wherein every node comprises m ports, where m1; and wherein the mobile communications site is configured for determining the topology according to the following operations: determining the number n of existing nodes; designating from the determined n nodes a master node and first and second slave nodes; selecting the first slave node as a first test slave node and preventing a communication of the other slave node(s); testing via which of the m ports of the master node and via which of the m ports of the first test slave node a communication between the master node and the first test slave node is possible, and storing these ports; selecting the second slave node as a second test slave node, and preventing a communication of the other slave node(s); testing via which of the m ports of the master node and via which of the m ports of the second test slave node a communication between the master node and the second test slave node is possible, and storing these ports; repeating the selecting and testing for each of other slave nodes, if any, wherein in selecting a different slave node is selected in each case as the test slave node; and generating a connection topology for the master node based on the stored ports.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Various embodiments of the example embodiment are described hereinafter by way of example with reference to the drawings for illustrative purposes. The same subjects have the same reference signs. In the drawings in detail:

(2) FIG. 1, 2A, 2B: show a basic functioning mode of a mobile communications site;

(3) FIG. 3A, 3B, 3C, 3D: show various embodiments of a node having a varying number of ports;

(4) FIG. 4A: shows an embodiment for determining the rank of a node;

(5) FIG. 4B, 4C, 4D: show an embodiment that indicates how the topology can be determined from FIG. 4A;

(6) FIG. 5A, 5B, 5C, 5D, 5E: show an additional embodiment that indicates how a topology can be determined; and

(7) FIG. 6A, 6B, 6C, 6D, 6E: show various flowcharts that explain how a method according to the example embodiment for determining topology operates in a mobile communications site.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

(8) FIGS. 1, 2A and 2B depict the basic functioning or the basic setup of a mobile communications site 1. A mobile communications site 1 comprises one or a plurality of base stations 2, which receives in particular data from a higher-level network 10 and transmits data thereto. The base station 2 prepares this data and allocates it to the respective mobile communications bands. Furthermore, an additional antenna arrangement 3 is provided, which comprises preferably a plurality of antenna elements, which are used to transmit and receive mobile communications signals in different mobile communications bands. In this example, the mobile communications site 1 also comprises two RET units 4. Via the RET unit 4, it is possible to actuate a phase shifter, which is arranged within the antenna arrangement 3. In this way, the down-tilt angle of the antenna arrangement 3 can be changed, by which different spatial regions are illuminated by the mobile communications site 1. A DTMA 5 (see FIG. 3C) could also be appropriate. As will be explained later in regard to FIGS. 3A, 3B, 5A and 5B, the mobile communications site 1 also comprises a plurality of combiners 6. The mobile communications site 1 may also comprise general monitoring units, by means of which temperature, air pressure, air humidity, wind speed, solar radiation and/or the orientation of the antenna arrangement 3 may be measured. A monitoring unit may also comprise a webcam to monitor the location of the mobile communications site 1. These components of the mobile communications site 1 are hereinafter also referred to as electrical functional units. These electrical functional units can be actuated via certain control commands (e.g. AISG commands). An AISG master 7 generates these control commands and transmits them to the AISG slaves. AISG slaves 8 may be those units, which were previously described as electrical functional units. Due to the length of time it takes until new devices are included in the AISG standard, currently not all desired devices can be actuated by the AISG master 7. Therefore, the electrical functional units also comprise devices, which are not to be counted as AISG slaves 8. The control commands are in this case usually transmitted via the same feeder cable 9a, 9b, over which the mobile communications signals are also transmitted. However, other frequency ranges are used in this case. The AISG signal is transmitted on a lower frequency of 2, 176 Hz, for example. This frequency lies below the frequencies that are used for mobile communications services. The AISG signal is an on/off keying signal, wherein the on-signal has a signal level of +5 dBm, and wherein the off-level comprises a signal level of 40 dBm. Data rates of at least 9.6 kbit/s are possible. The AISG standard thereby provides that the communication between the AISG master 7 and the AISG slaves 8 may only have a low latency. In contrast, it is different for communication between the AISG master 7 and a higher-level network 10 (e.g. routing or control device of the mobile communications operator). Such a connection, as can also occur via the Internet, has a higher latency.

(9) In FIG. 2A, the AISG master 7 is arranged separately from the at least one base station 2 (e.g. as separate hardware). The base station 2 is connected to the antenna arrangement 3 via two feeder cables 9a, 9b. Different polarisations (MAIN signal and DIV signal) of a mobile communications channel are transmitted via different feeder cables 9a, 9b, for example. The same may also apply for the MIMO paths.

(10) In contrast, in FIG. 2B the AISG master 7 is integrated directly in the base station 2, in particular as a software module.

(11) FIGS. 3A, 3B, 3C and 3D depict various embodiments of electrical functional units. Those electrical functional units, which can be connected to other electrical functional units and that can exchange data via other electrical functional units or with other electrical functional units, are also referred to as nodes. The mobile communications site 1 comprises at least n nodes 15.sub.1, . . . , 15.sub.n where n2, or n3. FIG. 3A shows such a node 15 in the form of a combiner 6, 6a. The depicted combiner 6, 6a is connected at the lower end of the antenna mast to the base stations 2. This is therefore a base station-side combiner 6, 6a. In contrast, FIG. 3B depicts a node 15 in the form of an additional combiner 6, 6b, which is mounted on the antenna mast in the vicinity of the antenna arrangement 3 and is connected thereto. This is an antenna-side combiner 6, 6b. The node 15 from FIG. 3C is a (single-band or dual-band) DTMA 5. The node 15 from FIG. 3D is the antenna arrangement 3. The RET unit 4 may also be arranged therein. Each node 15; 15.sub.1, . . . , 15.sub.n comprises m ports 16.sub.1, . . . , 16.sub.m where m1. A port 16.sub.1, . . . , 16.sub.m is also to be understood as being a terminal, wherein the communication preferably occurs in both directions (full-duplex or half-duplex, if applicable). Via this port 16.sub.1, . . . , 16.sub.m, node 15.sub.1, . . . , 15.sub.n can be connected to port 16.sub.1, . . . , 16.sub.m of another node 15.sub.1, . . . , 15.sub.n. To this end, a cable (e.g. a copper cable) is used, which can also include a respective feeder cable 9a, 9b.

(12) Both mobile communications signals and control commands (e.g. in the form of AISG signals) and/or a direct voltage to supply power to the antenna arrangement 3 can be transmitted via the individual ports 16.sub.1, . . . , 16.sub.m.

(13) In particular, there are nodes 15.sub.1, . . . , 15.sub.n, which function as end nodes. These include for example the antenna arrangement 3 from FIG. 3D or the base station 2. No additional nodes are connected to such an end node to enlarge the mobile communications site 1. However, there are also transit nodes, which receive signals and/or voltages at one or more ports 16.sub.1, . . . , 16.sub.m to output these again to another port 16.sub.1, . . . , 16.sub.m and provide them to another node 15.sub.1, . . . , 15.sub.n. Such transit nodes are depicted in FIGS. 3A, 3B and 3C. These involve in particular combiners 6 and DTMAs 5.

(14) A combiner 6 comprises a plurality of signal terminals, to which are supplied or which receive different mobile communications bands, and a common terminal, from which different mobile communications bands are outputted in a superimposed manner or received in a superimposed manner by the different mobile communications bands. In FIG. 3A, the common terminal is port 16.sub.1 and the signal terminals are ports 16.sub.2, 16.sub.3. In FIG. 3B, the common terminal is port 16.sub.3 and the signal terminals are ports 16.sub.1, 16.sub.2. The combiners 6 thereby preferably have a cavity design. Corresponding filter paths connect the common terminal to the signal terminals, wherein the filter paths act as band-pass filters and preferably let only one mobile communications band pass through in each case. Low-frequency signals (e.g. control signals, such as AISG signals) and direct voltages cannot be transmitted via the filter paths. Therefore, these are decoupled at the signal terminals via low-pass filters and are preferably routed via a separate circuit board to couple these in again at the common terminal (or vice versa).

(15) Nodes 15.sub.1, . . . , 15.sub.n also comprise a control device 17. This control device 17 may be a microcontroller or FPGA, for example. This control device 17 is designed to prevent a communications link via the individual ports 16.sub.1, . . . , 16.sub.m. Such a communications link involves communications signals (in particular low-frequency signals, but for example also those that lie between individual mobile communications bands or are also multiplexed (e.g. code-, . . . )), in other words preferably not the mobile communications signals themselves. In particular, a communications link, which is decoupled via a filter structure, can be prevented by the control device 17. Preferably, the combiners 6 and/or DTMAs 5 are designed in such a manner that a direct voltage, which is added at a port 16.sub.1, . . . , 16.sub.m, can also be outputted at at least one other port 16.sub.1, . . . , 16.sub.m. Control signals (e.g. AISG signals) or other communications signals, which are used for communication among the electrical functional units and are not mobile communications signals, may also be transmitted from one port 16.sub.1, . . . , 16.sub.m to another port 16.sub.1, . . . , 16.sub.m (in particular in a bidirectional manner). Preferably there is in this transmission path within the combiner 6 or the DTMA 5 a switch device, which can interrupt this transmission on layer 1. Preferably the direct voltage supply is not affected hereby. For this reason, the combiner 6 or the DTMA 5 comprises for example an additional crossover, which separates a direct voltage from a control signal (communications signal, such as AISG signal). Basically, it would also be possible for control signals, which are present at a port 16.sub.1, . . . , 16.sub.m, to be captured by the control device 17 and outputted to another port 16.sub.1, . . . , 16.sub.m. In this case, an interruption could occur at a higher protocol level (higher layer).

(16) FIGS. 4A, 4B, 4C and 4D explain by means of a simple embodiment how a topology in a mobile communications site 1 can be determined according to the example embodiment. For explanation purposes, in this context reference is made to the flowcharts of FIGS. 6A and 6B.

(17) The illustrative, highly simplified mobile communications site 1 is set up according to FIG. 4B. It comprises three nodes 15.sub.1, 15.sub.2 and 15.sub.3. Node 15.sub.1 comprises a port 16.sub.1, whereas node 15.sub.2 comprises two ports 16.sub.1, 16.sub.2, and wherein node 15.sub.3 has one port 16.sub.1.

(18) In this embodiment, the first port 16.sub.1 of the first node 15.sub.1 is electrically connected to the first port 16.sub.1 of the second node 15.sub.2. Furthermore, the first port 16.sub.1 of the third node 15.sub.3 is electrically connected to the second port 16.sub.2 of the second node 15.sub.2.

(19) In a first method step S.sub.1, the number of existing nodes 15.sub.1, 15.sub.2 and 15.sub.3 that can communicate with each other is determined. This can take place for example by the respective control devices 17 transmitting their presence within a node 15.sub.1, . . . , 15.sub.n sequentially within the scope of a communications signal (e.g. broadcast to all of their ports 16.sub.1, . . . , 16.sub.m), wherein this communications signal may also contain information about the type, the number of ports 16.sub.1, . . . , 16.sub.m and/or an individual rank. Preferably, the structure of the nodes 15.sub.1, . . . , 15.sub.n is selected in such a manner that no ring closure occurs. This is also not desired in the structure of a traditional mobile communications site 1, because in this case the communications signals are simply transmitted from the base stations 2 towards the antenna arrangement 3 and from the antenna arrangement 3 towards the base stations 2. It would also be possible that the number of nodes 15.sub.1, . . . , 15.sub.n is specified. It could then simply be verified for example whether these are interconnected as desired.

(20) The information about the number of existing nodes 15.sub.1, . . . , 15.sub.n is thereby stored by a higher-level control unit (not depicted) or by control device 17 of a node 15.sub.1, . . . , 15.sub.n. In this method step S.sub.1, an individual rank can be assigned to each node 15.sub.1, . . . , 15.sub.n. Such an allocation is depicted for example in FIG. 4A. The first node 15.sub.1 has the rank of 2, the second node 15.sub.2 has the rank of 1 and the third node 15.sub.3 has the rank of 3. This rank of each node 15.sub.1, . . . , 15.sub.n may result from individual features or can be derived from individual features. In this case, the rank stems from the individual rank number, which in this case corresponds to the serial number. For example, the second node 15.sub.2 has a serial number 18, which compared to the other serial numbers 23 and 31 represents the lowest number in this case, and accordingly results in the lowest rank. How the rank is determined is arbitrary, however. The only important consideration is that each node 15.sub.1, . . . , 15.sub.n has an individual rank, which is not used by any other node 15.sub.1, . . . , 15.sub.n.

(21) In a second method step S.sub.2, one of the identified n nodes 15.sub.1, . . . , 15.sub.n is designated as the master node and the other n1 nodes 15.sub.1, . . . , 15.sub.n are designated as slave nodes 15.sub.1, . . . , 15.sub.n. In the embodiment, the node 15.sub.1, . . . , 15.sub.n with the lowest rank is designated as the master node. In this case, this is the second node 15.sub.2.

(22) In a third method step S.sub.3, a slave node 15.sub.1, . . . , 15.sub.n is selected as a test slave node. The test slave node may for example be node 15.sub.1, . . . , 15.sub.n, which has the next lowest rank compared to the master node. In this case for the test slave node, this is the first node 15.sub.1. Furthermore, a communication of the other n2 slave nodes is (temporarily) prevented. In this case (only three nodes 15.sub.1, . . . , 15.sub.3 are depicted), only communication at the third node 15.sub.3 is prevented. This prevention may occur at all ports 16.sub.1, . . . , 16.sub.m of the slave nodes. Prevention may take place for a predetermined period or until a trigger signal is received by the corresponding slave nodes.

(23) A fourth method step S.sub.4 verifies via which of the m ports 16.sub.1, . . . , 16.sub.m of the master node, in other words the second node 15.sub.2, and via which of the m ports 16.sub.1, . . . , 16.sub.m of the test slave node, in other words the first node 15.sub.1, a communication between the master node and the test slave node is possible. Corresponding ports 16.sub.1, . . . , 16.sub.m of the master node and test slave node are stored accordingly.

(24) Thereupon, the fifth method step S.sub.5 is executed. In this method step, the third and fourth method steps S.sub.3, S.sub.4 are executed for every additional slave node, wherein in the third method step S.sub.3, in each case a different slave node is selected as the test slave node. Therefore, in the embodiment from FIG. 4B, the third node 15.sub.3 is selected as the new test slave node. Subsequently, whether a communication can be created is verified and, if so, via which ports 16.sub.1, . . . , 16.sub.m of the master node, in other words of the second node 15.sub.2, and the new test slave node, in other words the third node 15.sub.3. Corresponding ports 16.sub.1, . . . , 16.sub.m are stored for the master node as well as for the new test slave node.

(25) Thereafter, the sixth method step S.sub.6 can be executed. In this method step, a connection topology is generated for the master node, in this case for the second node 15.sub.2.

(26) The seventh method step S.sub.7 is executed below according to FIG. 6B. In this method step S.sub.7, the second, third, fourth, fifth and sixth method steps S.sub.2 to S.sub.6 are repeated. However, in the second method step S.sub.2 a different node 15.sub.1, . . . , 15.sub.n is designated as the (new) master node. This other node 15.sub.1, . . . , 15.sub.n is one of the earlier slave nodes, which can also include the earlier test slave node. The other nodes 15.sub.2, . . . , 15.sub.n, except for the old master node, are in turn designated as slave nodes. These slave nodes, which can also include the prior test slave node, are alternately (every time when method step S.sub.5 is executed) designated as the new test slave node. Now, a corresponding connection topology is generated for the new master node. The seventh method step S.sub.7 is thereby executed until at least n1 nodes 15.sub.1, . . . , 15.sub.n have functioned once as a master node. The connection topology for last node 15.sub.n may be generated using the already determined connection topologies for the previous master nodes.

(27) A corresponding connection topology for the first, second, and third nodes 15.sub.1, 15.sub.2 and 15.sub.3 can be seen in FIG. 4C. A solid line depicts the connections between the respective ports 16.sub.1, . . . , 16.sub.m of the respective nodes 15.sub.1, . . . , 15.sub.3 via which a communications link was successful. The dashed lines symbolise that a communications link between indicated ports 16.sub.1, . . . , 16.sub.m of the respective nodes 15.sub.1, . . . , 15.sub.3 was not possible. FIG. 4D depicts an adjusted topology, wherein the unsuccessful communications links are not depicted.

(28) The manner in which it is determined whether a communication between two ports 16.sub.1, . . . , 16.sub.m of two different nodes 15.sub.1, . . . , 15.sub.n is possible can be arbitrary. To this end, the AISG protocol or any other protocol (IP, SPI, I.sup.2C, and so on) may be used. In the simplest case, a low-frequency alternating voltage is modulated onto the line. Preferably, the communications link is low-frequency so that it can be interrupted or filtered out reliably by those nodes 15.sub.1, . . . , 15.sub.n at their respective ports 16.sub.1, . . . , 16.sub.m said nodes not being selected as master nodes or test slave nodes.

(29) Basically, the assigned ranks of the individual nodes 15.sub.1, . . . , 15.sub.n can be retained in the seventh method step S.sub.7. It is also possible that the previous slave nodes, which also include the test slave node, have new ranks assigned to them.

(30) After the seventh method step S.sub.7, the eighth method S.sub.8 is carried out. In this method step S.sub.8, a (complete) topology of the mobile communications site 1 is generated. To this end, the individual connection topologies for respective nodes 15.sub.1, . . . , 15.sub.n are used and combined. From this FIGS. 4C and 4D are obtained.

(31) FIGS. 5A, 5B, 5C, 5D and 5E depict a detailed embodiment of an illustrative mobile communications site 1 and explain how its topology can be determined. In this case also, method steps S.sub.1 to S.sub.8 are executed as was already explained in regard to FIG. 4A to 4D. The depicted electrical functional units are explained in greater detail in FIG. 3A to 3D.

(32) With reference to FIGS. 5A and 5B, it is shown that the mobile communications site there has seven nodes 15.sub.1, 15.sub.2, 15.sub.3, 15.sub.4, 15.sub.5, 15.sub.6 and 15.sub.7 (n=7). The first and seventh nodes 15.sub.1, 15.sub.7 are base station-side combiners 6, 6a, as described in FIG. 3A. At the signal terminals of each of these combiners 6, 6a, various base stations 2 are connected. The base station-side combiners 6, 6a are connected to the antenna-side combiners 6, 6b electrically via the feeder cables 9a, 9b, as was described in FIG. 3B. The antenna-side combiners 6, 6b are the second and sixth nodes 15.sub.2, 15.sub.6.

(33) The antenna-side combiners 6, 6b are connected to corresponding single-band DTMAs 5 as was described in FIG. 3C. In this case, a first single-band DTMA 5 is third node 15.sub.3, whereas a second single-band DTMA is fifth node 15.sub.5. According to FIG. 5B, second node 15.sub.2 is connected both to third node 15.sub.3 as well as to fifth node 15.sub.5. Sixth node 15.sub.6 is also connected to third node 15.sub.3 and fifth node 15.sub.5. Third and fifth nodes 15.sub.3, 15.sub.5 are connected to fourth node 15.sub.4, which is an end node in the form of the antenna arrangement 3, as was described in FIG. 3D.

(34) This antenna arrangement 3 may contain the RET unit 4 and/or various monitoring units, for example.

(35) In the first method step S.sub.1, the existing nodes 15.sub.1 to 15.sub.7 are determined, wherein a rank list is generated simultaneously. In the embodiment, third node 15.sub.3 has the lowest rank and fourth node 15.sub.4 has the highest rank. In this case, third node 15.sub.3 could be designated as the master node in the second method step S.sub.2. After method steps S.sub.1 to S.sub.6 have been performed, the connection topology for the master node is obtained. Thereafter, the seventh method step S.sub.7 is performed at least five times, wherein after this, the connection topology is obtained for n1 nodes 15.sub.1, . . . , 15.sub.n-1. The connection topology for nth node 15n can be determined from the other connection topologies. Thereafter, the eighth method step S.sub.8 is executed and the (complete) topology of mobile communications site 1 is determined as shown in FIG. 5D.

(36) The solid line indicates via which ports 16.sub.1, . . . , 16.sub.m the respective nodes 15.sub.1, . . . , 15.sub.n are connected to each other. FIG. 5E depicts another view of FIG. 5D, wherein individual nodes 15.sub.1, . . . , 15.sub.n are arranged according to the structure from FIG. 5B.

(37) FIG. 6A to 6E depict various flowcharts, which explain the method according to the example embodiment for topology determination in greater detail. The flow chart sequences in FIGS. 6A and 6B have already been described.

(38) FIG. 6C depicts an expanded flowchart of the method from FIGS. 6A and 6B. The flowchart in FIG. 6C comprises the additional method steps S.sub.9, S.sub.10 and S.sub.11. In the optional ninth method step S.sub.9, the generated (complete) topology is compared with a reference topology. This can be done by one of the nodes 15.sub.1, . . . , 15.sub.n or by a non-depicted control device.

(39) In a subsequent tenth method step S.sub.10, deviations between the generated (complete) topology and the reference topology are determined or outputted.

(40) In an eleventh method step S.sub.11, the generated (complete) topology of the mobile communications site 1 is transmitted to the higher-level routing and control device. Here it would also be possible for the detected deviations to be transmitted to the higher-level routing and control device. This can occur via a communications device, such as a hub, switch, router, gateway and/or modem. The method can also be started from the higher-level routing and control device via this communications device. Basically, the method can also be started directly from a computer (e.g. laptop) or a smartphone directly at the mobile communications site 1.

(41) FIGS. 6D and 6E show an embodiment in greater detail to explain how the fourth method step S.sub.4 could be designed more precisely. In the fourth method step S.sub.4, it is verified via which of them ports 16.sub.1, . . . , 16.sub.m of the master node and via which of them ports 16.sub.1, . . . , 16.sub.m of the test slave node, a communication between the master node and the test slave node is possible. In a method step S.sub.4a there, it is determined whether a communications link can be created to the test slave node by means of an exclusive communication via only one of the m ports 16.sub.1, . . . , 16.sub.m of the master node. If this is possible, then this one port 16.sub.1, . . . , 16.sub.m is stored for the master node. Basically it is possible here for the master node to send out a communications signal. Thereafter, method step S.sub.4b is executed (see FIG. 6E). In this method step, method step S.sub.4a is repeated until an attempt has been made to create a communications link to the test slave node for all m ports 16.sub.1, . . . , 16.sub.m of the master node exclusively.

(42) Method step S.sub.4c can be carried out in one embodiment. In this method step, one of the ports 16.sub.1, . . . , 16.sub.m on the master node is selected to communicate with the test slave node and a communication on the other ports 16.sub.1, . . . , 16.sub.m of the master node is prevented. In addition, method step S.sub.4a is executed, in which a communication is prevented to all ports 16.sub.1, . . . , 16.sub.m of the test slave node but one. This one port of the test slave node is stored in case a communications link can be created to the master node via this port 16.sub.1, . . . , 16.sub.m. In this context, the corresponding port 16.sub.1, . . . , 16.sub.m of the master node is also stored so that when generating the connection topology, the two ports 16.sub.1, . . . , 16.sub.m of the master node and the test slave node can be considered to be cross-linked.

(43) In a subsequent method step S.sub.4e, the previous method step S.sub.4d is repeated until an attempt has been made to create a communications link to the master node for all other m1 ports 16.sub.1, . . . , 16.sub.m of the test slave node exclusively. Successful communications links are stored accordingly. Method step S.sub.4c is initiated by the master node for example or is performed automatically (e.g. after time has passed) by the test slave node.

(44) Thereafter, method step S.sub.4f is performed, in which the previous method steps are repeated for all other ports 16.sub.1, . . . , 16.sub.m of the master node. This applies only for those ports 16.sub.1, . . . , 16.sub.m, for which it was determined in method step S.sub.4a that a communications link to the test slave node is fundamentally possible.

(45) Instead of method steps S.sub.4c, S.sub.4d, S.sub.4e and S.sub.4f, method steps S.sub.4a_1 and S.sub.4a_2 could also be performed. Method step S.sub.4a_1 is executed in method step S.sub.4a. In this method step, communication is prevented to all but one port 16.sub.1, . . . , 16.sub.m of the test slave node and this one port 16.sub.1, . . . , 16.sub.m is stored for the test slave node in the event that a communications link can be created to the master node via this port. In method step S.sub.4a, only port 16.sub.1, . . . , 16.sub.m of the master node is active, so that in the event of a successful communications link, a corresponding pair of ports 16.sub.1, . . . , 16.sub.m can be stored. Thereupon, method step S.sub.4a_2 is performed, in which method step S.sub.4a_1 is repeated until an attempt has been made to create a communications link to the one active switched master node for all additional m1 ports 16.sub.1, . . . , 16.sub.m of the test slave node exclusively. Method step S.sub.4a_2 is initiated by the master node for example or executed independently (e.g. after time has passed) by the test slave node.

(46) By repeating step S.sub.4b according to FIG. 6D, another port 16.sub.1, . . . , 16.sub.m of the master node is switched to active, or an attempt is made to create a communications link to the test slave node for the other ports 16.sub.1, . . . , 16.sub.m of the master node exclusively (in other words, in an iterative manner). By repeating the corresponding method steps S.sub.4a_1 and S.sub.4a_2, all ports or additional ports 16.sub.1, . . . , 16.sub.m are tested on the test slave node. Basically, it could be possible that a plurality of ports 16.sub.1, . . . , 16.sub.m of the master node are connected to one and the same port 16.sub.1, . . . , 16.sub.m of the test slave node. In this case, for every port 16.sub.1, . . . , 16.sub.m of the master node, an attempt is made to determine whether a communications link to every port 16.sub.1, . . . , 16.sub.m of the test slave node can be established.

(47) Each node 15.sub.1, . . . , 15.sub.n may have a differen t number of ports 16.sub.1, . . . , 16.sub.m, but each must have at least one port 16.sub.1, . . . , 16.sub.m. The type of communication between two nodes 15.sub.1, . . . , 15.sub.n may differ from the type of communication between two other nodes 15.sub.1, . . . , 15.sub.n. Basically, it would also be possible that the type of communication is identical for all nodes 15.sub.1, . . . , 15.sub.n.

(48) The test whether a communication between two ports 16.sub.1, . . . , 16.sub.m of various nodes 15.sub.1, . . . , 15.sub.n is possible can be determined by time-outs, for example. If no communication occurs within a certain, definable time span, it can be concluded for these ports 16.sub.1, . . . , 16.sub.m that there is no direct connection between the two ports.

(49) The invention is not restricted to the described embodiments. Within the scope of the invention, all described and/or illustrated features may be arbitrarily combined with one another.