SE515751C2 - Method and device for radio networks - Google Patents

Abstract

The present invention relates to a method at radio networks for determination of quality of frequency allocations. A first device is to be allotted information regarding the radio system available frequencies, channels. The first device can be allotted demands on frequency separation between channels within and between the base stations. The first device produces the frequency allocations for the base stations. The fulfilment demands for the produced frequency allocations are calculated. Further a presentation for the frequency allocations is determined where the not fulfilled demands are categorized and weighted according to importance. A decision device produces a difference between the presentation and selects that presentation which best comes up to the demands. The decision device determines whether the selected presentation is acceptable or not. Acceptable solutions are implemented in the base stations at which the definition of quality for the frequency allocations is given by the obtained presentation for the frequency allocations.

Description

x i -ya 02! I 4 Ii 5 in i i i i s I i i 2 i v i 'l rf' '77 then IJ! European publication 559 949 describes a method for computer-aided cell planning of a radio network. The method is based on a digital terrain database. The coverage area of the base stations is superimposed on a digitized map and displayed graphically. Interference characteristics for different sets of transmitter parameters are analyzed and the result is used as a parameter for the channel assignment.

DESCRIPTION OF THE INVENTION TECHNICAL PROBLEM With frequency allocation in radio networks, there is a need to obtain a measure of the quality of the frequency allocation. The quality determination is important in connection with frequency allocations, where the requirement for frequency separation between channels in or between base stations is not met. As the capacity of the radio networks increases, more and more problems arise with the requirements for frequency separation not being met. Determining the precedence of different frequency assignments over each other is a very difficult task. Measurements of deviation from the frequency separation have so far not existed. Furthermore, there are no methods for distinguishing the significance of different requirements not met on frequency separation between the channels within and between the base stations.

There is thus a need to find methods and devices which in a simple manner distinguish and point out which frequency assignments, in a given amount, are preferable to the other. Furthermore, there is a need to find methods and devices that evaluate which solutions can be introduced into the network at all with an acceptable risk of interference between current channels. The present invention is intended to solve the stated problems.

THE SOLUTION The present invention relates to a method in radio networks for determining the quality of frequency assignment. The radio network is assigned a number of frequencies, channels, which are to be distributed between base stations in the radio network. To avoid interference between channels, requirements for frequency separation between the channels within and between the base stations have been established. When a frequency assignment does not meet the requirements, violations of these arise. Said crime is categorized with respect to the size of the crime. Furthermore, a weighting of the various crimes is introduced, whereby disturbances that are more serious for the network's function are given a higher weight than less serious crimes. The distribution of the weighted offenses is then presented. The distribution indicates the number of weighted crimes in the different categories or in total. The obtained distributions for a first and second frequency assignment, respectively, are compared. The frequency assignment that has the lowest number of serious offenses in its distribution is selected. The quality of the frequency allocation is stated by the distribution, whereby the number of deviations from the established requirements indicates the quality. The category is further divided into intervals. The breakdown distribution is calculated from a function. The function is a function of the requirement and the frequency separation obtained weighted by the current weight. The function is bij = (uij-Afij) * vij, Afij u denotes the requirement, Af denotes the frequency separation, vil 'denotes the weight.

The distribution of the weighted crimes is presented in diagram form.

Presentation in diagram form facilitates visual control of the results obtained.

The invention further relates to a device for radio networks for determining the quality of frequency assignments. A first means is to assign information regarding 'fi *' m1 frequencies, channels, and the channel requirement in the base stations. The requirements for frequency separation between the channels in and between the base stations are further assignable to the first means. The first body further produces proposals for frequency allocations for the base stations. In the first means, a further calculation is made of the fulfillment of requirements for the produced frequency assignments. For frequency assignments where the requirements are not met, a presentation is prepared. In the presentation, the deviations from the set requirements are categorized according to significance.

Furthermore, a weight function has been introduced to increase the significance of serious violations of established requirements. The result is transferred to a decision-making body that determines a difference between the presentations and selects the presentation that best meets the requirements. The decision-making body further investigates whether the chosen presentation, despite deviations from the requirements, can be accepted or not. Acceptable solutions are then implemented in the current base station (s). A quality determination of the frequency assignment is given by the presentation obtained for the frequency assignment.

ADVANTAGES The invention thus allows the quality of a radio network to be easily indicated.

Furthermore, an opportunity is given to determine in advance a minimum level on the network that is acceptable. The invention further allows a measure of the quality of the network to be obtained. It is further possible to compare the quality of different frequency assignments, with the best assignment being selectable. The invention can also be used for both manual and automated frequency assignment. The algorithm used to evaluate different frequency assignments against each other is easy to exchange. It is also easy to compare the results obtained. The invention thus constitutes a tool which considerably simplifies the frequency assignment in cases where set requirements for frequency separation cannot be fully met. _ (II tzi DESCRIPTION OF FIGURES Figures 1 and 2 show examples of different frequency assignments with a number of fractions indicated.

Figure 3 shows the basic structure of the invention, where a: defines frequency requirements, exclusions and weights, pre-allocated frequencies, available frequencies and prohibited frequencies. b: frequency assignment c: fractional calculation d: presentation e: decision PREFERRED EXECUTIVE FORM In the following, the inventive idea is described with reference to the figures and the designations therein.

In a radio network comprising a number of base radio stations, a limited number of available frequencies, channels, shall be distributed in an optimal way between the base stations in the radio system. In order to obtain a disturbance-free radio network, requirements have been set for frequency separation. The requirements for frequency separation, exclusions, state which channels can be used in one and the same base station or in nearby base stations without disturbing each other. In the radio systems that are established or modified, the desire to expand capacity is strong. However, an increase in capacity may mean that the requirements set from the outset cannot be fully met. The various violations that arise in this connection with the set requirements affect the function of the network to varying degrees. Thus, in some cases, two channels located in one and the same base station cannot be accepted at all. However, the same channels may be allowed in base stations that are adjacent to each other under certain circumstances.

Decisive for whether two channels can be used is in this case in which 5 i zsl: I I S i 'Ü., When "Jia: J extent said channels interfere with each other and other channels in their surroundings.

In the following, two base stations i and j are considered. Furthermore, an exclusion requirement u is defined. In measurements or calculations, a frequency separation Af has also been determined. The relationship between the exclusion requirement and the frequency separation constitutes a measure of the risk of interference between the relevant base stations. A violation of the exclusion requirement is obtained when Af <uij. In other cases, the set requirements are met. In the following, only the case is considered that Afij <uij where i ochj denotes base station in the respective j.

In a radio network where frequencies are to be distributed between base stations, the frequency requirement, exclusions and weights, pre-allocated frequencies and available frequencies for a first unit are defined according to Figure 3.

Unit A, forwards information regarding input data, for example exclusions that make crime calculations and partly to a decision-making body, E, which makes decisions regarding found results. From A, further information regarding frequency requirements, etc. is transmitted to the unit B. In unit B, calculations and frequency assignments are made to the various base stations.

The frequency allocation takes place in ways that have previously been established and are known. Unit B can operate according to different alternatives. An alternative is that a number of different alternatives to frequency allocations are calculated. Another alternative is that only one frequency assignment is calculated and forwarded to the crime calculation body, C.

According to the previous assumption, the frequency allocation entails a violation of the exclusions. A function is built into the crime calculation body that takes into account the exclusion requirement, u, and the relationship of the frequency frequency obtained, Af, to each other. The various crimes are further classified in relation to the size of the crime. In this case, crime size refers to the degree of disturbance risk that exists between the base stations in question. The performed calculation result is transferred to a presentation module, D. In the presentation module, the crimes are arranged in relation to the size of the crime and the number of crimes within each crime size. The presentation thus obtained is presentable in different ways with respect to how the presentation is to be used. For visual comparison, the information is suitably arranged in diagrammatic form according to Figures 1 and 2. Other presentations can also be used depending on how the information is to be used. The presentations are then transferred to a decision-making body, E. The decision-making body compares the results obtained and decides which result is preferable. For example, if two presentations according to Figures 1 and 2 have been obtained, the presentation according to Figure 1 is preferable. The diagram shows that more serious crimes occur in allocation according to Figure 2. The decision-making body further compares the result obtained with the requirements set regarding crimes that can be accepted. If the result cannot be accepted, the information is returned to unit A. New calculations and new frequency assignments are then calculated and undergo the same procedure as described above. If no frequency allocations can be found that meet the requirements, either the conditions must be changed or a decision made that the desired frequency allocations are not feasible. If a result is obtained that is acceptable, this is transmitted to the radio network where the frequency plan is determined and entered.

The diagrams that can be obtained from the presentation body further indicate a rating on the quality of the frequency assignment. When assessing which frequency allocation is preferable, the decision-making body can, for example, calculate a difference between the distributions of the different frequency allocations. The difference obtained clearly indicates which frequency assignment is preferable.

Alternative presentation: Crime list containing - Category for crime - Size of the crime - Exclusion requirements - Weight - Base station i and j involved - Frequencies at each base station that gives rise to the crime. 5 5 in The list can be sorted on any parameter (as above) and formatted or presented in an appropriate way.

A number of frequency assignments are in this way obtainable for the radio system. The frequency allocations can partly fully meet the set requirements, and partly refer to a number of solutions that do not meet the requirements according to the previous description. A comparison of the results with regard to frequency allocations is hereby obtained, whereby the consequence of changed frequency allocations in the various base stations and adjacent radio networks is obtainable. The presentations obtained in this case present the decision-making body in the form of a difference. The difference then uses the decision-making body to determine which solution is optimally best. In cases where the solutions do not meet the set requirements, the optimal solution is utilized, whereby evaluation of the quality of the network is obtained. The quality obtained on the network, with the conditions that have been set, is then evaluable with regard to the desired quality that is sought. It is also possible in this way to obtain a limit for what the network can perform under set conditions. It is then up to you to decide whether a solution can be accepted with regard to the conditions you set, or that the conditions must be changed, for example changing the number of channels in the network, the number of channels that may be used in base stations EtC.

The invention is not limited to the embodiment shown above but may be subject to modifications within the scope of the appended claims and inventive concept.

Claims (10)

PATENT REQUIREMENTS Method in radio networks, for quality determination of frequency assignment, which radio network is assigned a number of frequencies, channels to be distributed between base stations in the radio network and requirements for frequency separation between the channels within and between base stations are established, and breakages occur when frequency assignment does not meet the requirements. characterized in that the offenses are registered with regard to severity, that the offenses are assigned weights whose value increases with the severity of the offenses, that a distribution over the weighted offenses is produced, that the distributions for a first and a second frequency assignment are compared. , that a number of frequency allocations are produced which fully or partially meet the requirements, that the consequence of changes in the frequency allocations in adjacent base stations and radio networks is obtained, and if the solutions do not meet the set requirements an optimal solution is used and that the frequency allocation The quality of the network is indicated by the distribution where a limit for the network's performance under set conditions is obtained, and a decision is made as to whether the solution can be accepted or whether set conditions should be changed. Method according to claim 1, characterized in that the categorization of the crimes takes place at intervals. Method according to claim 1, characterized in that the crime distribution is calculated from an algorithm which depends on the requirement and the frequency separation obtained weighted by the current weight. Method according to one of the preceding claims, characterized in that the algorithm used is bij = (uij-Af¿j) * vij Afij u denotes the requirement, Af denotes the frequency separation, v denotes the weight, and i and j denote the base stations i and j. Method according to one of the preceding claims, characterized in that the distribution over the weighted fractures is presented in diagrammatic form. F7 "? I '774 ciae) / Jl A device in the radio network for determining the quality of frequency assignments, wherein a first means is assignable information regarding frequencies available in the radio system, base stations and the channel requirement at the radio network, and the first means is assignable frequency separation requirements between the channels in and between the base stations, and the first means produces the frequency allocations for the base stations, characterized in that the first means is arranged to calculate the fulfillment of the requirements for the produced frequency allocations, and establish a presentation for the frequency allocations, where the non-fulfilled requirements are categorized and weighted according to importance. acceptable or not, that acceptable solutions are implementable in the base stations, the quality determination in the frequency assignment being given by the presentation obtained for the frequency assignment, and that a limit for no The company's performance is presentable under established conditions, whereby decisions are made as to whether the solutions are acceptable or whether the conditions should be changed. Device according to claim 6, characterized in that the first means categorically divides the offenses into intervals. Device according to claim 6 or 7, characterized in that a decision-making body is arranged to produce a difference between the presentations and to select the presentation which best meets the requirements. Device according to claims 6 to 7, characterized in that the decision means is arranged to present the crimes in diagrammatic form. Device according to claim 8, characterized in that the decision means is arranged to determine a difference between the received presentation and set requirements, that the decision means uses the difference to determine whether the presentation obtained for the frequency assignment is acceptable or not and which of two presentations are preferable.