Method allowing realistic simulation of a telecommunication system

The This invention relates to a method for simulating operating conditions of a telecommunication system with at least two radio base stations, and two mobile users of the system, which together form a communication network form.

Such Methods are currently before an actual physical implementation of a telecommunication system for Optimizing utilization of radio base stations in the system are included, and a development of a decision-forming Network infrastructure to manage the network, used to define a system for providing an optimal Communication service with the lowest possible cost is capable. <patcit><text>US 5,561,841</text></patcit> shows such a Construction.

Some Simulation methods are known as mapping methods and currently used for optimizing telecommunication systems of the GSM type be that as 2G (what second generation stands) systems are known to produce pictures, show the geographic coverage areas, each area a cell forms belonging to a single base station, which Figure allows activating the supply of the system, while is followed with the general principle that, when a mobile User is located within a cell and if the associated base station not saturated is the mobile users with a satisfactory communication service will be supplied.

A Activation of a quality of service in telecommunications systems of UMTS type, also known as 3G (which for third Generation is) systems are known, by a method not be obtained exactly as described above, namely mainly because 3G systems perform no frequency planning, as they performed at 2G systems is where two different mobile users, which in the same geographical area are located, two different communication frequencies are allocated to an interference between the users to minimize. In 3G systems If no such frequency planning performed, so that communication interference may occur between mobile users and what the quality of each ongoing communication will adversely affecting to an extent, the one user to another according to the specific situation of each user varies, which means the extent The method described above can not be predicted can.

On Another known method, the useful Monte Carlo methods is called, is mainly in generating a plurality of snapshots, each descriptive for a predetermined, randomly generated situation of the system. Each snapshot then displays the location of all mobile users of the system in the corresponding situation, the base stations with which users communicate, and a power level that each mobile user exerts on its ongoing communication, which enables the degree of Derive interference that generates a user for other users, which are located in its vicinity, and thus the extent to which interference generated by other users each Users in each randomly generated situation adversely affected.

The Monte Carlo method allows thus for each random form generated situation, the number of mobile users, to to which provided a satisfactory stel no communication service available is, and allows a random activation of the total communication quality by the simulated system is offered.

The usefulness of the Monte-Carlo method is, however, the following problems impaired: Since this method performs a statistical analysis of the simulated system performs, is a great Number of snapshots for That the analysis is reliable is required. be huge computational resources thus be required to analyze situations that, while accidentally are produced, will often be inconsistent with each other. A group , Of such situations, which are analyzed in such a way that they form a whole, will thus not be representative of realistic developments in relation to the operating states be of the simulated system. This problem will be more sensitive, if the number of simulated users and the size of the system are important, such as in simulations, the tenfold or thousands of users and hundreds of base stations included.

furthermore allows even though the Monte-Carlo method, a total activation an average communication quality allows which is provided by the simulated 3G system available by under other parameters, interference generated by the user and the adverse effect of the interference on ongoing communications randomly in each considered generated situation is the Monte Carlo method not individual communications be monitored to the quality To activate the service, which is supplied to individual users and is perceived by this that the ultimate Aktivie&lt;?page 3?&gt;tion criterion is because one of the main objectives of a system simulation is to help in defining a system which itself is on the necessities will adapt the user to obtain a customer satisfaction.

The present invention aims at solving the above problems off by a method for simulating operating conditions of a telecommunication system to disposal is provided, which process less computing power than the Monte Carlo method requires and permits the quality of service activate that delivered to individual users of the system becomes.

But be according to a first aspect of the invention, in a simulation method described in Substantially in a preparing a plurality of snapshots the system is, each snapshot for a predetermined configuration the communication network is descriptive, two consecutive Snapshots by at least one correlating parameter connected with each other.

The Fact that two successive snapshots together are connected, allows the number of generated situations to cut down on those which are consistent with one another, and thus realistic about what result it allows, to reduce the amount of computing power to run the Simulation method according to the invention is necessary with respect to, for example, the Monte Carlo method. This advantage of the invention is critical when large systems with, for example, hundreds of base stations and tens of thousands are simulating of mobile users.

According to a second aspect of the invention the predefined parameter correlating Variations with respect to the time exposed.

A Such selection for the correlating parameter enables a historical overview of the operating states Of the system, and thus the development during the Time of individual communications from its beginnings up to to pursue their ends, which allows a result of the quality of service activate, asked the individual users available becomes.

at a specific embodiment of the Invention, a position of at least one mobile user and for users belonging Velocity vector used as correlating parameters.

at an advantageous embodiment of the Invention is a degree of Power signals by at least one mobile user transmitted, used as correlating parameters.

at a variant of this advantageous embodiment of the invention a data rate of at least one ongoing communication, formed between a mobile user and a base station is used as correlating parameters.

These advantageous embodiments allow the invention a consistent and realistic modeling of user-generated Interference affecting any ongoing communication adversely can. These embodiments allow Also, an occurrence or disappearance of communications in nearby of each user, the terms or ideas or concepts are made solely in the context of the historical overview make sense of the virtue of the invention is provided and the quality of the current communication can affect the user.

The Invention also relates to a simulation device, the process, a perform If, as described above.

The abovementioned characteristics of the invention, and others will become more apparent upon reading the following description, the in reference to the accompanying FIGS is specified, amongst which:

<figref idrefs="S12">1</figref> on functional diagram showing a simulation device, a method according to the invention used, and

<figref idrefs="S13">2</figref> on Schema showing two successive snapshots on the same image, which are obtained by means of a simulation method according to the invention.

<figref idrefs="S12">1</figref> shows diagrammed a A simulation device SD, the operating conditions of a telecommunication system is intended to simulate, in which a method is used according to the invention. This device contains SD a first database GD, which is to store geographical data, belonging to a landscape over which the telecommunication system is to be used, such as Models of obstacles such as buildings, Mountains, etc. The simulation device SD further includes a second database BSD, intended to store data pertaining to radio base stations, the form a network that is included in the system, such as a geographical location of each base station, a maximum number of Communications that moment given each base station to a can handle, or a maximum transmission power, the &lt;?page 4?&gt;each base station can apply to their ongoing communications, etc. The Simulationsvorri rect SD contains a third database UED that store a collection of files is, each file being associated with a mobile user, the will appear in the course of the simulation, and in chronological Order listed consecutive coordinates, speeds, transmission powers contains or data rates, to ongoing communications between each user and to be assigned to a base station. The first and second Database GD and BSD thus contain data of a structural nature, for the Use of the wireless network are representative, that is included in the system and of geographical constraints, among which operate the network, while the third database UED contains dynamic data, the for Events representative are, during the operation of the system will occur.

at this embodiment of the invention are the first, second and third database GD, BSD and UED by a user of the simulation device SD loading by means of a loading interface LDINT.

The includes simulation device SD a computing unit CU intended to process data obtained by the above first, second and third database GD, BSD and UED are delivered by means of respective data signals Dg, Dbs and Due, which processing is clocked by a clock signal Clk, which is supplied by a clock generator XTAL. During a Analysis step which at each active edge, such as a rising edge, of the clock signal CLK starts, the arithmetic unit CU a snapshot of the system by bringing a group of Data from the first, the second and the third database GB, BSD and UED and performing a synthesis of the data by determining, among others, which mobile users in communication with which base station is the extent to power, the current through each user on its communication is applied and / or severity of interference generated by a particular user is, and its adverse produce effects on communications of other users. The third database UED may be arranged to, inter alia, to provide correlating parameters currently specified values Data rates for the various communications that at through the system to supports appropriate moments are, in which case the computing unit CU an amount of power will determine which of apply any ongoing communication of a mobile user must to ensure that the corresponding specified data rate is taken into account, and an interference level that is associated with this level of performance. In another possible embodiment will provide a value of the power that the third database EUD applied to each ongoing communication, and the computing unit CU during each analysis step only the extent of must determine interference, generated by the ongoing communications.

At the the computing unit CU a group end of each analysis step provides of output data signals Ds representative of the results of the above described Synthesis to a register REG for storage purposes, which register REG is connected to a display interface DISP, the results provide simulation to the user of the simulation device SD should. The storage operations performed by register REG can are brought into a sequence by means of a clock signal is derived from clock signal Clk, as for example, a signal, the respect opposite in phase to the clock signal CLK is, as is the Case in this embodiment is what provides a sufficient set that the data are securely stored. The display interface DISP may a Means for interpreting the output data Ds be provided, which allow could be that the display interface DISP from the output data Ds values ​​of Parameters extracted, the representative for a communication quality is how a power-to-Interterenz ratio, to be assigned to a respective mobile users, and to Displaying such values, for example in varying colors or Brightnesses on a map, which shows the telecommunications system.

The invention allows Thus, a user of the simulation device SD with a historical overview of the operating states the simulated system to provide, and thus the development of the Over time of individual communications from its origins to to track toward their ends, which in turn allows the quality provided the service to activate the individual users available becomes.

<figref idrefs="S13">2</figref> shows on the same image SNPS12 two successive snapshots, which are generated by means of the invention, of a very simple telecommunication system. This system contains a first, a second and a third radio base station BS1, BS2 allotted or BS3, which a first, a second and a third coverage area are also called cells C1, C2 and C3. Data that the describe above characteristics, are of a structural Nature and would are stored in the first and second databases, the are described above. It should be noted that the maxi&lt;?page 5?&gt;times degree of Power which a base station to its ongoing communications can apply, in the course of time may vary, and thus cause can that variations in the scope of their coverage area occur. Such data would, though they are of a dynamic nature, but is preferably in the second database described above are stored.

at a first snapshot, a first, a second and a third mobile users who are EU11, EU21 and EU31, called shown in first positions by the respective coordinates (X11, y11), (x21, y21) and (x31, y31) are identified which a first group trained by correlating parameters, a second set of correlating parameters by velocity vectors is V11, V21 and V31 are formed corresponding to the respective mobile users are EU11, EU21 and EU31 allocated. The values ​​of these correlating parameters can are fetched from the third database described above.

at This example considers only two dimensions and are all movements the mobile users are coplanar, in order to simplify the drawing. A third parameter correlating who does not in this drawing it can be shown how the power on by each mobile user its ongoing communication is applied, or a data rate, specifically for communication, may also be used, and for that in the above-described third database are stored.

at a second snapshot, the first, second and third mobile users, which are then called EU12, EU22 and EU32, shown in second positions by the respective coordinates (X12, y12), (x22, y22) and (x32, y32) are identified which fed through the third database described above could be, but by the computing unit on the basis of the previous speed vectors V11, V21 and V31 in combination with the previous coordinates (x11, y11), (x21, y21) and (x31, y31) may also have been calculated. New Velocity vectors V12, V22 and V32 are in this second Snapshot to the respective mobile users EU11, EU21 and EU31 allocated.

The Fact that the first and the second snapshot of a compound share, allows to see how the quality of ongoing communications by the movements of the first, are the second and third mobile user affected or impaired becomes. It seems to be such that in the second snapshot all three users will be relatively close to each other while are far from their respective base stations, said the latter leads, that a respective user a considerable amount of power applying to its ongoing communication, and a large amount of interference generated over which the other user will be given their proximity very sensitive. The historical overview, granted the virtue of the invention is, will permit to observe a corresponding drop of communication quality. It should also be noted that the invention allows, phenomena a sudden simulate breakage, which term only thanks to the abovementioned historical overview makes sense, as in this example an appearance of a fourth mobile user UE42 in the second snapshot at coordinates (X42, Y42), and thus in the vicinity the other mobile users what to deterioration perceived by each user communication quality contribute.

According to the velocity vectors V21, V22 and V23 of the second snapshot is the third mobile user UE32 of the third cell C3 to the second cell C2 between the second snapshot and a next which is not shown in this drawing, move, which will result, that a handover occurs. Handovers are phenomena which occur very frequently in cellular telecommunication systems, and simulation can only be made if the simulation method allows, represent such notions as previous cell and next cell, Thanks to this embodiment, the Invention is the case, two successive snapshots are connected by correlating parameters whose values ​​regarding vary on the time, which in turn allows a chronological to define order in the course of the simulation.