Procedure for determining the optimal location of signal transmitting part-units belonging to wireless local networks and a set of tools for doing the procedure

The invention relates to a set of tools for facilitating the determination of the optimal location of signal transmitting part-units belonging to wireless local networks, which contains a signal transmitting part-unit and a receiving part-unit co-operating with the signal transmitting part-unit via radio frequency signal transfer connection, and the receiving part-unit is connected to a data collecting and processing part-unit.

The invention also relates to a procedure for determining the optimal location of signal transmitting part-units belonging to wireless local networks, in the course of which a signal transmitting part-unit is placed at one point and a receiving part-unit is placed at another point of the operation area of the local network, radio frequency test signal is broadcast from the signal transmitting part-unit, the test signal is received at the receiving part-unit, the measured signal received at the receiving part-unit is transferred to the data collecting and processing part-unit, and then the signal transmitting part-unit is relocated and the cycle needed for generating further measured signals is repeated to the necessary extent, finally the measured signals stored in the data collecting and processing part-unit are examined, and on the basis of the characteristics of the measured signals the physical characteristics of the operation area of the local network are determined, on the basis of which the signal transmitting part-units are located.

Today wireless local networks operating in bands for which no licence is required are becoming increasingly wide-spread, with their help all types of different communication, control and monitoring tasks can be solved in the field of healthcare, industry or safety engineering. The basic requirements to be fulfilled by such systems involve the realisation of optimal area coverage and the minimisation of disturbing effects representing a load on the environment. The fulfilment of these expectations is based on the careful location of the signal transmitting part-units on which the network is based.

So far several solutions have been used for determining the location of signal transmitting part-units. In the case of the known procedures a test network is used, which consists of independent transmitters co-operating with each other and one single receiver. The signals broadcast by the transmitters are received by the receiver. The location of the measurement is recorded as well as the measured value, and after relocating the measuring point, that is the receiver, the process is continued until the required accuracy is reached.

The measuring set called AGILENT E6474A is a tool suitable for measuring the coverage of location area of wireless local networks, which tool uses the so-called "drive-test" principle.

A study by Alex Hills, Jon Schlegel, Ben Jenkins entitled "Estimating Signal Strengths in the Design of an Indoor Wireless Network" (IEEE Transactions on Wireless Comm, vol. 3, no. 1, January 2004, 17) relates to this solution.

The basic disadvantage of the known solutions is that in the course of surveying the area not enough attention is paid to determining the damping and reflection effect of circumstances influencing the transmission of radio waves, such as space delimiting units, e.g.: walls, furniture and other equipment, but instead mostly the try method is used to realise appropriate network location.

Further disadvantages deriving from this are that there is a large demand for live labour and for preliminary location, and due to the tools and procedures used the measured values are not accurate enough and the coverage map is incomplete.

A further disadvantage is that the results received do not refer to what the coverage data of a given area is based on. It is not possible to determine whether the given value was measured because of reflection or it only reflects the damping of a space delimiting unit. Because of this the optimal location of signal transmitting part-units rests upon unstable foundations.

It is also a disadvantage that using the known tools and procedures no accurate four- dimensional coverage map can be made, that is a coverage map determining the field intensity values measured at individual points in space, which also reduces the probability of locating signal transmitting part-units at the right points.

It is also unfavourable that due to overplanniiig deriving from the nature of the planning process, in the course of the location of local networks more signal transmitting part-units and other tools may be used than justified, which increases investment and then maintenance costs and also increases the risk of failures.

Our aim with the invention was to eliminate the deficiencies of known tools and procedures and to create a version, which provides installers with a highly efficient and accurate set of tools at a low cost and with the help of which deviations caused by space delimiting units influencing local coverage can be surveyed using a low amount of live labour, and the circumstance causing the low value of field intensity on a given area can also be determined.

The set of tools according to the invention is based on the recognition that if an ordinary transmitter is combined with a receiver under specific operating conditions, and from the transmitter-receiver units created in this way a mobile measuring unit controlled on the basis of novel principles is constructed, in which due to the switching system of the unusual transmitter-receiver units special chain measuring can be realised, then at a measuring point accurate reflection measurement can be performed relating to several points of the examined area nearly at the same time, and then the received values can be forwarded to the independently operating receiver, and as a result of this several independent physical parameters can be determined with respect to the given point, and so the task can be solved.

The procedure according to the invention is based on the recognition that if a space delimiting unit has both a damping and a reflecting effect, then the signal broadcast towards the space delimiting unit is partly reflected from its one side, from the reflecting surface of the space delimiting unit, that is it remains on its signal broadcasting side, so

it can be received and stored there. If then this information relating to reflection is broadcast to the other side of the space delimiting unit with the help of a novel scanning measuring unit with a certain capacity, then by receiving the signal there and determining its content and the intensity of the received signal, the damping and possible reflection effect of the space delimiting unit (wall, equipment) situated on the given area can be determined in one single step, and so by using a small amount of live labour, in a short period of time, practically without any human intervention it can be determined at high precision what sort of physical characteristics the space delimiting units have that have an influence on the transmission of radio waves, and on the basis of these physical characteristics the optimal locations of the signal transmitting part-units of the network can be determined accurately.

In accordance with the set aim the set of tools according to the invention for facilitating the determination of the optimal location of signal transmitting part-units belonging to wireless local networks, - which contains a signal transmitting part-unit and a receiving part-unit co-operating with the signal transmitting part-unit via radio frequency signal transfer connection, and the receiving part-unit is connected to a data collecting and processing part-unit, - is constructed in a way that a switched-receiver part-unit situated in the environment of the signal transmitting part-unit is allocated to the signal transmitting part unit, the signal transmitting part-unit and the switched- receiver part-unit are connected to each other via an internal switching part-unit, and in this way a harmonised transmitter-receiver unit is constructed from the signal transmitting part-unit, the internal switching part-unit and the switched-receiver part- unit, and at least two harmonised transmitter-receiver units are combined with the operation control part-unit connected to the individual internal switching part-units to form a scanning measuring unit, where the scanning measuring unit has a data store part-unit and a displacement indicator part-unit.

A further feature of the set of tools according to the invention may be that it has one single data store part-unit and the data store part-unit is connected directly to the operation control part-unit.

In the case of a different construction of the set of tools at least some of the harmonised transmitter-receiver units are supplemented with local control units inserted between the operation control part-unit and the internal switching part-units, and in this way the operation control part-unit is connected to the local control units, and the data store part-unit is divided into partial data store units, and the partial data store units are connected to the local control units.

In the case of another different version of the invention the scanning measuring unit and the displacement indicator part-unit are attached to a carrying body in a fixed way, and the controlled transmitter-receiver units of the scanning measuring xinit are arranged on the carrying body next to each other, along one single line, at a certain distance from each other.

In the case of a favourable construction of the set of tools the carrying body also has a grip, and a starting unit and/or a reporting unit and/or a connecting unit connected to the operation control part-unit of the scanning measuring unit is situated on the grip.

In the case of another different construction of the invention the carrying body is fixed to a moveable supporting frame, and a starting unit and/or a reporting unit and/or a connecting unit connected to the operation control part-unit of the scanning measuring unit is situated on the supporting frame.

In the case of a favourable construction of the set of tools the displacement indicator part-unit contains one or more acceleration measuring sensors.

In the case of a further version of the invention the data collecting and processing part-unit is a personal computer. The data collecting and processing part-unit and the receiver part-unit are connected to each other via a wireless data transmission channel.

In accordance with the set aim the procedure according to the invention for determining the optimal location of signal transmitting part-units belonging to wireless local networks, - in the course of which a signal transmitting part-unit is placed at one point and a receiving part-unit is placed at another point of the operation area of the

local network, radio frequency test signal is broadcast from the signal transmitting part- unit, the test signal is received at the receiving part-unit, the measured signal received at the receiving part-unit is transferred to the data collecting and processing part-unit, and then the signal transmitting part-unit is relocated and the cycle needed for generating further measured signals is repeated to the necessary extent, finally the measured signals stored in the data collecting and processing part-unit are examined, and on the basis of the characteristics of the measured signals the physical characteristics of the operation area of the local network are determined, on the basis of which the signal transmitting part-units are located, - is based on the principle that at least two signal transmitting part-units and a switched-receiver part-unit co-operating with them and a scanning measuring unit containing a partial data store are placed at the same measuring point, then from the one signal transmitting part-unit of the scanning measuring unit a primary information signal is transmitted, which primary information signal is received by the switched-receiver part-units allocated to the other signal transmitting part-units, and then the received primary information signal is stored temporarily in the partial data store belonging to the given switched-receiver part-units, then another signal transmitting part-unit is activated and with the help of the given signal transmitting part- unit the value of the primary information signal stored in the partial data store belonging to the given signal transmitting part-unit is transmitted to the receiver part-unit as a test signal of a given level, the level of the test signal transmitted to the receiver part-unit and the value of the primary information signal sent in the test signal is received and then interpreted and evaluated in the data collecting and processing part-unit, the steps of operation are repeated as many times as necessary at different points, and the physical characteristics of the operation area of the local network are determined in this way.

A further feature of the procedure according to the invention may be that in the test signal transmitted from the individual signal transmitting part-units to the receiver part- unit, beside the value of the primary information signal, the position co-ordinates of the signal transmitting part-unit belonging to the value recording of the given primary information signal are also sent, and in this way the value of the primary information

signal and the level of the transmitted test signal are interpreted and evaluated together with the position co-ordinates of the measuring point.

In the case of another realisation of the procedure the scanning measuring unit is taken along the delimiting line of the space delimiting units situated on the operation area of the local network, at a distance of 0.2-0.8 metres from this delimiting line, and radio frequency transmission is performed in the ISM frequency band.

The most important advantage of the set of tools according to the invention is that due to the novel scanning measuring unit, despite its simple construction and operation, it has high measurement accuracy and no special skills are needed for its operation, and practically — apart from moving the scanning measuring unit - it performs its task without any human intervention.

Its further advantage is that due to the harmonised transmitter-receiver units used in groups, measuring can be performed at a large number of points situated along the same line, practically at the same time, and during this measuring both the damping and reflection value can be determined, which was not possible using the known tools.

A further advantage deriving from this is that the complete four-dimensional coverage map of a given area can be prepared using a smaller amount of live labour, within a shorter period of time and significantly more accurately than with the known tools and the procedures using them, which results in saving live labour and significantly reducing cost and time demands.

It must also be regarded as an advantage that by measuring reflection at several points measuring inaccuracies caused by interference deriving from multi-path transmission are eliminated, which is essential from the optimal location of signal transmitting part-units. The economic advantage deriving from the higher accuracy of measuring is that due to more accurate planning and less overplanning fewer signal transmitting part-units are needed, as a result of which investment costs are reduced both on the side of assets and on the side of live-labour needed for fitting.

Another advantage is that due to the displacement indicator part-units belonging to the scanning part-unit there is no need to record the position co-ordinates of the measuring points separately, because they are included in the signal provided by the scanning measuring unit itself, and in this way the space co-ordinates of the measuring point are automatically allocated to the measured values.

A further advantage of the procedure according to the invention is that due to the use of the scanning measuring unit all essential parameters of the space delimiting units situated on the area of location influencing the transmission of radio waves can be determined by making one single quick measurement, and using these results the accurate four-dimensional model of the area of location can be made, on which the optimal location of the individual signal transmitting part-units can be marked directly, and in this way the most efficient network that can be set up using the lowest number of assets can be determined in a short period of time and using a small amount of live labour.

Furthermore, an advantage relating to the procedure is that the coverage map made on the basis of the measuring results can be updated at a later point, when the area is changed, for example in the case of building construction work or installing new equipment, and in a given case, using the updated coverage map, the signal transmitting part-units can be reorganised in a simple way.

The economic advantage of the procedure deriving from the above is that the accurate mapping of the area of location can be performed at a low cost, and due to the placement of an optimal number of signal transmitting part-units the investment costs can be minimised.

Below the set of tools according to the invention is described in detail in connection with a construction example, on the basis of a drawing. In the drawing

figure 1 is the diagrammatic view of a version of the set of tools according to the invention,

figure 2 is the block diagram of a possible construction of the scanning measuring unit belonging to the invention, figure 3 is the block diagram of another different construction of the scanning measuring unit.

Figure 1 shows a realisation of the set of tools according to the invention, which is suitable for determining the reflection and damping characteristics of the space delimiting unit 6 with a reflecting member 7, which characteristics are essential from the aspect of radio frequency transmission, and on the basis of these characteristics for making a four-dimensional coverage map of the given area, which is essential from the aspect of locating a wireless local network.

It can be seen that the set of tools contains a receiver part-unit 4, which is connected to the data collecting and processing part-unit 5 by transmitting information. In the present case this is a wireless connection, but obviously the receiver part-unit 4 may also be connected to the data collecting and processing part-unit 5 with a cable. It is also possible that the receiver part-unit 4 and the data collecting and processing part-unit 5 form one single structural unit. Practically the data collecting and processing part-unit 5 is a computer, for example a portable laptop. Beside the receiver part-unit 4 and the data collecting and processing part-unit 5 one or more scanning measuring units 1 also form part of the set of tools.

In this case one of the scanning measuring units 1 is a small unit that can be easily moved by hand, and it contains a harmonised transmitter-receiver unit 10, a harmonised transmitter-receiver unit 20 and a harmonised transmitter-receiver unit 30 attached to a carrying body 3. The carrying body 3 has a grip 3a to make it easy to handle, and on the grip 3 a there is the starting 41, the reporting unit 42 and the connecting unit 43. It must be pointed out here that a functionally operating scanning measuring unit 1 can also be constructed by combining harmonised transmitter-receiver unit 10 and harmonised transmitter-receiver unit 20, but in order to increase the accuracy of measuring and determine the desired parameters in a reliable way an arrangement consisting of three

units, that is harmonised transmitter-receiver unit 10, harmonised transmitter-receiver unit 20 and harmonised transmitter-receiver unit 30, is definitely more favourable.

Figure 2 shows the block diagram of a version of the manual scanning measuring unit 1. It can be seen that the harmonised transmitter-receiver unit 10 attached to the carrying body 3 contains a signal transmitting part-unit 11, a switched-receiver part-unit 12 and an internal switching part-unit 13. Harmonised transmitter-receiver unit 20 also contains a signal transmitting part-unit 21, a switched-receiver part-unit 22 and an internal switching part-unit 23, while harmonised transmitter-receiver unit 30 contains a signal transmitting part-unit 31, a switched-receiver part-unit 32 and an internal switching part- unit 33. Harmonised transmitter-receiver unit 10, harmonised transmitter-receiver unit 20 and harmonised transmitter-receiver unit 30 are attached to the carrying body 3 situated at a "T" distance from each other. The displacement indicator part-unit 2 is also situated on the carrying body 3, and in the grip 3 a fixed to the carrying body 3 there is an operation control part-unit 40, a data store part-unit 44 connected to the operation control part-unit 40, a starting unit 41, a reporting unit 42 and a connecting unit 43.

Figure 2 also shows that beside the starting unit 41, the reporting unit 42 and the connecting unit 43, the operation control part-unit 40 is also connected to the displacement indicator part-unit 2, and the signal transmitting part-unit 11, the switched- receiver part-unit 12 and the internal switching part-unit 13 of the harmonised transmitter-receiver unit 10, the signal transmitting part-unit 21, the switched-receiver part-unit 22 and the internal switching part-unit 23 of the harmonised transmitter- receiver unit 20, and the signal transmitting part-unit 31 , the switched-receiver part-unit 32 and the internal switching part-unit 33 of the harmonised transmitter-receiver unit 30 are also connected to the operation control part-unit 40.

In this case the operation control part-unit 40 is a microcontroller, which scans and schedules the operation of harmonised transmitter-receiver unit 10, harmonised transmitter-receiver unit 20, harmonised transmitter-receiver unit 30, the displacement indicator part-unit 2 and the data store part-unit 44.

The task of the signal transmitting part-unit 11 of harmonised transmitter-receiver part-unit is to transmit signals of a given information content at a given time, while the task of the switched-receiver part-unit 12 is to receive the signals transmitted by the signal transmitting part-unit 21 of the harmonised transmitter-receiver unit 20 and by the signal transmitting part-unit 31 of the harmonised transmitter-receiver unit 30 of the scanning measuring unit 1 at a given time and to send them to the data store part-unit 44, and the task of the internal switching part-unit 13 is to determine on the basis of the command of the operation control part-unit 40 whether in the case of the harmonised transmitter-receiver unit 10 the signal transmitting part-unit 11 or the switched-receiver part-unit 12 shovild be activated.

In the course of the operation of the scanning measuring part-unit 1 shown in figure 2, the operation control part-unit 40 can be turned on with the help of the stalling unit 41. When the starting unit is turned on 41, the reporting unit 42 shows that the scanning measuring unit 1 has been activated, and the operation control part-unit 40 sets the content of the data store part-unit 44 at reference signal or deletes it and at the same time interrogates the displacement indicator part-unit 2 about the actual displacement value or sets it to zero, and then regards this value as reference value when determining the displacement of the scanning measuring unit 1. After this the operation control part-unit 40 sends a command to the internal switching part-unit 13 of the harmonised transmitter-receiver part-unit 10 instructing it to turn on the signal transmitting part-unit 11 of the harmonised transmitter-receiver unit 10 and make it a transmitter by this, while it sends a signal to the internal switching part-unit 23 of the harmonised transmitter-receiver part-unit 20 and to the internal switching part-unit 33 of the harmonised transmitter-receiver part-unit 30 instructing them to activate switched- receiver part-unit 22 and switched-receiver part-unit 32.

At this point the signal transmitting part-unit 11 of the harmonised transmitter- receiver unit 10 regarded as the actual transmitter sends an initial message of a certain intensity - in the present case a reference signal restored in the data store part-unit 44 - as a test signal towards the space delimiting unit 6, which signal passes through the

space delimiting unit 6 and reaches the receiver part-unit 4, and, for example, by doing so it provides information that the scanning measuring unit 1 has started its operation. On the basis of the first test signal received the receiver part-unit 4 also starts its routine operation to be performed during measuring.

In a given case a part of the test signal transmitted by the signal transmitting part-unit 11 of the harmonised transmitter-receiver unit 10 onto the space delimiting unit 6 may be reflected from the reflecting member 7 embedded into or placed on the surface of the space delimiting unit 6, the reflected signal is detected by switched-receiver part-unit 22 and switched-receiver part-unit 32 - operating in reception mode - of harmonised transmitter-receiver unit 20 and harmonised transmitter-receiver unit 30 of the scanning measuring unit 1 , and then it is transmitted to the data store part-unit 44 with the help of the monitoring and control of the operation control part-unit 40.

After this operation step has taken place within only a few hundredths of a second, the operation control part-unit 40 shifts the measuring cycle further and turns off the signal transmitting part-unit 11 of harmonised transmitter-receiver unit 10 and the switched-receiver part-unit 22 of harmonised transmitter-receiver unit 20, while it activates the switched-receiver part-unit 12 of harmonised transmitter-receiver unit 10 and the signal transmitting part-unit 21 of harmonised transmitter-receiver unit 20, and the switched-receiver part-unit 32 of harmonised transmitter-receiver part-unit 30 remains turned on as before.

The signal transmitting part-unit 21 of harmonised transmitter-receiver unit 20 - again with the help of the operation control part-unit 40 - reads the measured value stored in the data store part-unit 44 and transmits this information towards the space delimiting unit 6, in the direction of the receiver part-unit 4. The receiver part-unit 4 receives the information from the signal transmitting part-unit 21 and sends to the data collecting and processing part-unit 5. At the same time a part of the signal sent from the signal transmitting part-unit 21 of harmonised transmitter-receiver unit 20 to the space delimiting unit 6 may be reflected again, and at this point it is detected by the switched-

receiver part-unit 12 of harmonised transmitter-receiver unit 10 and by the switched- receiver part-unit 32 of harmonised transmitter-receiver unit 30, and then it is sent to the data store part-unit 44 of the operation control part-unit 40.

Next the information stored in this second measuring step is transmitted - together with the data already stored in the earlier measuring steps - by the signal transmitting part-unit 31 of harmonised transmitter-receiver part-unit 30 through the space delimiting unit 6 towards the receiver part-unit 4, when the operation control part-unit 40 activates the signal transmitting part-unit 31 of harmonised transmitter-receiver part-unit 30, the switched-receiver part-unit 12 of harmonised transmitter-receiver unit 10 and the switched-receiver part-unit 22 of harmonised transmitter-receiver unit 20.

After the measuring sequence of the scanning measuring unit 1 at a given point, when the receiver part-unit 4 has sent all the measured data to the data collecting and processing part-unit 5, from the received information the data collecting and processing part-unit 5 decimalises and arranges the right results and stores the final result.

In the course of the movement of the scanning measuring part-unit 1 the displacement indicator part-unit 2 detects displacement and forwards the measured result to the operation control part-unit 40, which compares this value to the reference value measured when the scanning measuring unit 1 was turned on and determines the direction and extent of the displacement of the scanning measuring unit I ₃ which values are then sent to the receiver part-unit 4 together with the values measured at the given new measuring point. In this way the displacement determined by the displacement indicator part-unit 2 is taken into consideration by the data collecting and processing part-unit 5 when evaluating the received results, in the course of making the coverage map.

When finishing measuring, the starting unit 41 of the operation control part-unit 40 is pressed again, as a result of which the process is stopped and an "end of measuring" signal is sent to the receiver part-unit 4.

In the case that the operation control part-unit 40 of the scanning measuring unit 1 needs to be reprogrammed, the connecting unit 43 of the scanning measuring unit 1 needs to be connected to the programming equipment - not shown in the figures — , and in this way the necessary changes can be entered into the operation control part-unit 40.

On examining figure 1 again, beside the manual scanning measuring unit 1 a larger scanning measuring unit 1 can also be seen in it, and beside harmonised transmitter- receiver unit 10, harmonised transmitter-receiver unit 20 and harmonised transmitter- receiver unit 30 there are further harmonised transmitter-receiver units on it, and all of them are attached to the carrying body 3 situated at a permanent "T" distance from each other. Here the carrying body 3 — due to its height, which is 2 meters in the present case - is fitted onto a supporting frame 3b having rolling elements 3 c, and in this way the scanning measuring unit 1 can be easily rolled along the high space delimiting unit 6 with the help of a trolley type moving structure. A scanning measuring unit 1 of this type can be easily rolled along the walls of buildings too. The supporting frame 3b supporting the carrying body 3 may contain the starting unit 41, the reporting unit 42 and the connecting unit 43, but obviously the may be also placed on the carrying body 3 itself.

Figure 3 shows a realisation of the scanning measuring unit 1, where the carrying body 3 is fitted onto a supporting frame 3b having rolling elements 3c forming wheels. In this case too there is the harmonised transmitter-receiver unit 10 containing the signal transmitting part-unit 11, the switched-receiver part-unit 12 and the internal switching part-unit 13. But in the case of this construction the harmonised transmitter-receiver unit 10 also has a partial data store 14 and a local control unit 15, and the displacement indicator part-unit 2 containing acceleration measuring sensor 2a and acceleration measuring sensor 2b is also allocated to the harmonised transmitter-receiver unit 10 itself. Due to acceleration measuring sensor 2a and acceleration measuring sensor 2b, the displacement indicator part-unit 2 can detect movements in any direction in the plane carrying the space delimiting unit 6 and transmit such movements towards the

receiver part-unit 4, and so the location of the measuring results needed for making a highly accurate spatial coverage map can be determined in a simple way.

The task of the partial data store 14 involves the permanent storage of the data received by the lined-receiver part-unit 12 of the harmonised transmitter-receiver unit 10 and the displacement information sent by acceleration measuring sensor 2a and acceleration measuring sensor 2b of the displacement indicator part-unit 2. Practically the partial data store 14 performs the same task as the data store part-unit 44 in the case of the manual scanning measuring unit 1, with the difference that in this case information measured by only one harmonised transmitter-receiver unit - marked with reference number 10 in the present case. The role of the local control unit 15 belonging to harmonised transmitter-receiver unit 10 is to co-ordinate the operation of the signal transmitting part-unit 11, the switched-receiver part-unit 12, the internal switching part- unit 13 and the partial data store 14 of the harmonised transmitter-receiver part-unit 10.

Obviously harmonised transmitter-receiver unit 20 also contains a signal transmitting part-unit 21, a switched-receiver part-unit 22, an internal switching part-unit 23, a partial data store 24 and a local control unit 25 as well as a displacement indicator part- unit 2. The same stands for harmonised transmitter-receiver unit 30, which contains a signal transmitting part-unit 31, a switched-receiver part-unit 32, an internal switching part-unit 33, a partial data store 34 and a local control unit 35 as well as a displacement indicator part-unit 2.

In figure 3 it can be also seen that the operation control part-unit 40 is connected to local control unit 15, local control unit 25 and local control unit 35, so here the operation control part-unit 40 co-ordinates only local control unit 15, local control unit 25 and local control unit 35, while local control unit 15 itself regulates the operation of harmonised transmitter-receiver unit 10, local control unit 25 regulates the operation of harmonised transmitter-receiver unit 20, and local control unit 35 regulates the operation of harmonised transmitter-receiver unit 30. Obviously the starting unit 41, the reporting

unit 42 and the connecting unit 43 are also connected to the operation control part-unit 40.

During the operation of the scanning measuring unit 1 shown in figure 3, after the starting unit 41 is turned on, the operation control part-unit 40 sends a signal to the local control unit 15 of the harmonised transmitter-receiver unit 10, to the local control unit 25 of the harmonised transmitter-receiver unit 20 and to the local control unit 35 of the harmonised transmitter-receiver unit 30. On receiving the signal the local control unit 15 sets the partial data store 14 to initial position and records the signals transmitted by acceleration measuring sensor 2a and acceleration measuring sensor 2b of the displacement indicator part-unit 2 so that from this point on the given physical position is regarded as reference point. The same initial steps are performed by the local control unit 25- of harmonised transmitter-receiver unit 20 and by the local control unit 35 of harmonised transmitter-receiver unit 30. Finally, after these basic processes have been performed, the reporting unit 42 of the scanning measuring unit 1 is also turned on and it shows that the scanning measuring unit 1 is ready to perform the measuring process.

After the "ready" signal of the reporting unit 42, first the operation control unit 40 sends a signal to the local control unit 15 of the harmonised transmitter-receiver unit 10 to make it switch over the internal switching part-unit 13 and activate the signal transmitting part-unit 11, and to send the value stored in the partial data store 14 - in the form of a test signal of a certain intensity - towards the receiver part-unit 4 situated in the direction of the space delimiting unit 6. While on the basis of the instruction of the operation control part-unit 40 the local control unit 15 activates the signal transmitting part-unit of the harmonised transmitter-receiver unit 10, at the same time it sends a signal to the local control unit 25 of harmonised transmitter-receiver unit 20 instructing the internal switching part-unit 23 therein to activate the switched-receiver part-unit 22, and the same takes place in the case of harmonised transmitter-receiver unit 30, where the local control unit turns on the switched-receiver part-unit 32 via the internal switching part-unit 33.

As a result of this, from the test signal of a certain intensity sent from the signal transmitting part-unit 11 towards the space delimiting unit 6, the switched-receiver part- unit 22 of the harmonised transmitter-receiver unit 20 receives the signal reflected from the reflecting member 7 of the space delimiting unit 6, and it sends the received signal to the partial data store 24 via the local control unit 25. The same is performed by the switched-receiver part-unit 32 of the harmonised transmitter-receiver unit 30, which sends the reflected signal to the partial data store 34 via the local control unit 35.

It is obvious that if beside harmonised transmitter-receiver unit 10, harmonised transmitter-receiver unit 20 and harmonised transmitter-receiver unit 30 there are further harmonised transmitter-receiver units attached to the carrying body 3, then the same process described above takes place in those too.

After the signal transmitting part-unit 11 of harmonised transmitter-receiver unit 10 has transmitted the test signal, the operation control part-unit 40 sends a further signal to the local control unit 15 of the harmonised transmitter-receiver unit 10, which turns off the signal transmitting part-unit 11 and turns on the switched-receiver part-unit 12 with the help of the internal switching part-unit 13. At the same time, on the basis of the instruction sent to the local control unit 25 of harmonised transmitter-receiver unit 20, the local control unit 25 turns off the switched-receiver part-unit 22 and turns on the signal transmitting part-unit 21 with the help of the internal switching part-unit 23. In this measuring step the switched-receiver part-unit 32 of harmonised transmitter- receiver unit 30 remains in operation.

At this point with the help of the local control unit 25 the turned on signal transmitting part-unit 21 reads the signal - transmitted earlier by signal transmitting part-unit 11 and reflected from the reflecting member 7 - stored in the partial data store 24 and sends it to the receiver part-unit 4, which sends the received information to the data collecting and processing part-unit 5. The signal reflected from the reflecting member 7 of the space delimiting unit 6 in the direction of the scanning measuring unit 1 is received by the switched-receiver part-unit 12 of harmonised transmitter-receiver

unit 10 and by the switched-receiver part-unit 32 of harmonised transmitter-receiver unit 30 and then it is stored in data store 14 and data store 34.

When signal transmitting part-unit 21 has finished transmission, the operation control part-unit 40 sends a control signal again to local control unit 15, local control unit 25 and local control unit 35, as a result of which local control unit 35 turns off the switched-receiver part-unit 32 and turns on the signal transmitting part-unit 31. At the same time local control unit 25 turns off the signal transmitting part-unit 21 and turns on the switched-receiver part-unit 22, while in the present case the switched-receiver part- unit 12 of harmonised transmitter-receiver unit 10 remains in operation. In this case the activated signal transmitting part-unit 31 sends the signal - containing the value reflected from the signal transmitted by signal transmitting part-unit 11 and signal transmitting part-unit 21 — read from the partial data store 34 of harmonised transmitter- receiver unit 30 with the help of the local control unit 35 towards the space delimiting unit 6. The signal passing through the space delimiting unit 6 is received by the receiver part-unit 4, while the signal reflected by the reflecting member is received — among others - by the switched-receiver part-unit 12 of harmonised transmitter-receiver unit 10 and is stored in partial data store 14.

These processes are repeated as many times as many harmonised transmitter-receiver units are fitted onto the carrying body 3 altogether, in the end the signal transmitting part-unit 11 of harmonised transmitter-receiver unit 10 is activated, and it is the last one to transmit the signal saved in the partial data store 14 of harmonised transmitter- receiver unit 10 towards the receiver part-unit 4. This signal contains the value reflected from the test signal transmitted by all signal transmitting part-units of the carrying body 3, obviously in an identifiable way, so that in the course of evaluation the individual values can be clearly allocated to signal transmitting part-unit 21, signal transmitting part-unit 31 or all further signal transmitting part-units.

When all the harmonised transmitter-receiver units have operated both in transmission and reception mode, and the signal sent by them has passed through the

receiver part-unit 4 and arrived in the data collecting and processing part-unit 5, the data collecting and processing part-unit 5 processes the received information and creates the coverage map of the vertical section belonging to the given measuring point "A" in the vertical band belonging to measuring point "A", for example at 10 cm intervals from the supporting frame 3b up to a height of 2 metres. Then the supporting frame 3b is moved and it is the turn of a measuring point other than measuring point "A", but there the measured data is transmitted by the signal transmitting part-unit 11 of harmonised transmitter-receiver unit 10 - and obviously signal transmitting part-unit 21, signal transmitting part-unit 31 and all the rest too - with the displacement values indicated by acceleration measuring sensor 2a and acceleration measuring sensor 2b of the displacement indicator part-unit 2.

After performing the desired measurement, by pressing again the starting unit 41 of the operation control part-unit 40 the process is stopped and the operation control part- unit 40 also sends an "end of measuring" signal to the receiver part-unit 4.

After describing the set of tools according to the invention, below the procedure according to the invention is described in detail.

Example 1 :

In the case of this version of the procedure according to the invention the optimal position co-ordinates of the signal transmitting part-units forming the wireless network were determined on an area situated in the environment of the wall structure of a building part. In the course of the procedure first a scanning measuring unit 1 - described above - was placed in measuring point "A" situated at a distance of 0.5 metres from the wall forming the space delimiting unit 6, and then it was turned on. After turning on the scanning measuring unit 1, a primary information signal and the coordinates of the position of the scanning measuring unit 1, that is measuring point "A", were transmitted in the ISM frequency band, which, on the one hand, were received by the receiver-part-unit 4 placed on the other side of the wall forming the space delimiting unit 6 and forwarded to the data collecting and processing part-unit 5. On the other

hand, the primary information signal transmitted from the signal transmitting part-unit 11 but potentially reflected from the reflecting member 7 of the space delimiting unit 6 was also received in switched-receiver part-unit 22 and linked receiver part-unit 32 of the scanning measuring unit 1 , and the received value was saved temporarily in partial data store 24 and partial data store 34.

In the following step of the procedure the signal saved in the partial data store 24 was transmitted through the space delimiting unit 6 to the receiver part-unit with the help of the signal transmitting part-unit 21 as a test signal of a given energy level, and the level and content of the test signal arriving at the receiver part-unit 4 through the space delimiting unit 6 - which is basically the reflection value of the primary signal - was sent to the data collecting and processing part-unit 5, where it was evaluated.

It must be pointed out here that by sending the primary information "wrapped up" in the test signal to the receiver part-unit 4, practically two measurements were performed in one single step. On the one hand, by measuring the energy of the test signal arriving at the receiver part-unit 4, the damping effect of the given section of the space delimiting unit 6 was determined, and on the other hand, by forwarding the primary information signal sent in the test signal, the reflection of practically the same section of the space delimiting unit 6 was also determined.

After repeating the above measuring steps as many times as the number of signal transmitting part-unit and switched-receiver part-unit pairs in the scanning measuring unit 1, the scanning measuring unit 1 was moved along the wall forming the space delimiting unit 6, and the complete measuring cycle was repeated enough times to be able to determine the damping and reflection characteristics of the space delimiting unit 6 wall section. After sending all the testing signals to the data collecting and processing unit 5, with the help of a computer program containing a suitable algorithm the data was evaluated and the four-dimensional coverage map of the environment of the space delimiting unit 6 was produced. The four-dimensional coverage map showed the value of coverage at a given point of the spatial X-Y-Z co-ordinate system taking the

examined frequency as a basis. Finally, with the help of the four-dimensional coverage map the points were determined in the environment of the space delimiting unit 6, that is wall section, at which the signal transmitting part-units of the local wireless network should be practically located.

It must be pointed out here that with the help of the scanning measuring unit 1 used in the procedure, by performing one single measuring process it is possible to determine to a high degree of accuracy the physical characteristics of the space delimiting unit 6 itself that are essential from the aspect of the transmission of radio waves, such as its damping and reflection characteristics at each point.

List of references

scanning measuring unit displacement indicator part-unit 2a acceleration measuring sensor 2b acceleration measuring sensor

carrying body 3 a grip

3 b supporting frame

3 c rolling element

receiver part-unit

data collecting and processing part-unit

space delimiting unit

reflecting member harmonised transmitter-receiver unit 11 signal transmitting part-unit

12 switched-receiver part-unit

13 internal switching part-unit

14 partial data store unit

15 local control unit

harmonised transmitter-receiver unit 21 signal transmitting part-unit

22 switched-receiver part-unit

23 internal switching part-unit

24 partial data store unit

25 local control unit

0 harmonised transmitter-receiver unit 31 signal transmitting part-unit

32 switched-receiver part-unit

33 internal switching part-unit

34 partial data store unit

35 local control unit 0 operation control part-unit 41 starting unit

42 reporting unit

43 connecting unit

44 data store part-unit

"A" measuring point

"T" distance