METHOD FOR DETERMINING RADIO NETWORK HOT SPOT AREA LOCATION, AND TRANSCEIVER

Abstract: The invention relates to a method for determining radio network hot spot area location and a transceiver, the radio network comprising at least one base station (20) and a plurality of subscriber terminals (10), the hot spot area having a concentration of subscriber terminals. The base station (20) forms local areas and transmits a location code on the basis of which the subscriber terminals (10) identify the base stations (20) belonging to the local area and are signalling with the base station (20). The transceiver (30) comprises transmission means (32) for transmitting a location code not belonging to the local area to the subscriber terminals (10), calculation means (33) for calculating the number of signalling subscriber terminals (10) and the calculation means (33) for calculating the distance between the transceiver (30) and the subscriber terminals (10) signalling with the transceiver (10).

Description: METHOD FOR DETERMINING RADIO NETWORK HOT SPOT AREA LOCATION, AND TRANSCEIVER FIELD OF THE INVENTION The invention relates to a method for determining radio network hot spot area location, the radio network comprising at least one base station and a plurality of subscriber terminals, the hot spot area having a concentration of subscriber terminals, in which method the base stations form location areas and transmit location code on the basis of which the subscriber terminals are signalling with the base station and identify the base stations belonging to the same location area. The invention also relates to a transceiver used in a radio network for determining hot spot area location, the radio network comprising at least one base station and a plurality of subscriber terminals, the hot spot area having a concentration of subscriber terminals, and the base stations forming local areas and transmitting location code on the basis of which the subscriber terminals identify the base stations belonging to the local area and are signalling with the base station. BACKGROUND OF THE INVENTION It is previously known to define a concentration of subscriber terminals, or hot spot areas, of a radio network, the GSM (Global System for Mobile communication) and the DCS (Digital Cellular System) radio networks in particular. The hot spot areas comprise a plurality of subscriber terminals compared with the available radio network capacity in the same area. In the hot spot areas the radio network is overloaded or it is more likely to become overloaded than any other part of the radio network. Overload could have been detected for example by using a radio network management computer. Overload can be avoided if a base station is built in the radio network hot spot area and a new cell is formed, for example a microcell. In this way additional capacity is obtained to the radio network. There can be several hot spot areas in the radio network area. It has previously been known to define the hot spot areas using a receiver located in the radio network area. The receiver has measured the signal strength of subscriber terminals, for example that of mobile phones, located in the radio network area. The number of subscriber terminals has been determined based on the signal strength. The distance between the subscriber terminal and the base station has further been determined from the signal strength, the distance having been utilized in the definition of the hot spot area. However, there have been certain drawbacks in the prior art method. Power control, which is meant for saving the battery in the subscriber terminal, is used in the subscriber terminals. The subscriber terminal power control affects the strength of the transmitted signal. If power control has been used in the subscriber terminals of the radio network and the hot spot area of the radio network has simultaneously been defined, then the exact definition of the hot spot area location has not been successful. Moreover, the precise number of the subscriber terminals located in the hot spot area has not been established by using the method. What has been described above has resulted in that e.g. the microcell formed on the basis of the prior art method has arrived at an incorrect position. SUMMARY OF THE INVENTION An object of the present invention is to implement a method for defining precisely a radio network hot spot area and particularly a hot spot area location. This is achieved with the method set forth in the preamble characterized in that a location code not belonging to the location area is transmitted to the subscriber terminals, the number of signalling subscriber terminals is calculated on the basis of said location code and a substantially direct distance that the location code has travelled to the subscriber terminal is calculated using signalling. The transceiver of the invention is characterized in that the transceiver comprises transmission means for transmitting location code not belonging to the local area to the subscriber terminals, calculation means for calculating the number of signalling subscriber terminals and the calculation means for calculating a distance between the transceiver and the subscriber terminals signalling with the transceiver. The method of the invention has several advantages. Location code not belonging to the location area is transmitted in the radio network, and based on the signalling code the number of signalling subscriber terminals is calculated. Furthermore, in the method of the invention the substantially direct distance that the location code has travelled to the subscriber terminal is cal culated using signalling. Location code is preferably transmitted from various locations of the radio network, whereby a distribution of the subscriber terminals can be determined. The precise location of the hot spot area is defined on the basis of the substantially direct distance that the location code has travelled to the subscriber terminal. The location of the hot spot area is thus precisely defined using the method, whereby for example a new base station can be located in one go to a preferable terrain. The preferred embodiments of the method of the invention are also disclosed in the enclosed dependent claims and the preferred embodiments of the transceiver of the invention are disclosed in the enclosed dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS In the following the invention will be described in greater detail with reference to examples in the accompanying drawings, in which Figure 1 shows a radio network in which a transceiver of the invention is used and Figure 2 shows the transceiver of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Figure 1 shows a radio network comprising plural subscriber terminals 10, base station 20 and transceiver 30. The radio network is for example a GSM or a DCS network or an equivalent network. Subscriber terminals 10 communicate with base station 20 if necessary. Subscriber terminals in the radio network of the Figure belong to the coverage area of base station 20. The coverage area of base station 20 forms a location area to subscriber terminals 10 located in the area. When subscriber terminal 10 moves outside the location area, then subscriber terminal 10 updates location information on the basis of which subscriber terminal 10 knows its location. Base station 20 updates information from subscriber terminals 10 located within its coverage area. If subscriber terminal 10 does not leave the coverage area, then the location information of subscriber terminal 10 do not have to be updated. There may be several base stations 20 in the radio network area handling the traffic of the same location area. Base station 20 comprises antenna 21 using which the base station transmits particular code on the basis of which subscriber terminals 10 located within the coverage area of base station 20 identify their location. In the example of the Figure LAC code (Location Area Code) is used for identifying the location. Different location areas have their own LAC codes. When subscriber terminal 10 updates location information, then subscriber terminal 10 simultaneously signals with base station 20. Generally the radio network is divided into cells which each one forms its own coverage area. If there are in the area of base station 20 of the example constantly plural subscriber terminals 10 attempting to establish connections compared with the available capacity of base station 20, then base station 20 eventually becomes overloaded. When overloading occurs a large number of subscriber terminals 10 cannot establish a connection fast enough, for example with another subscriber terminal 10. Consequently, a hot spot area has been formed substantially in the area of base station 20. If a new base station 20 or, for example a microcell, is built in the hot spot area, then the overloading of base station 20 is prevented. However, the coverage area of base station 20 can be extensive in which case it becomes difficult to establish the hot spot area location. Figure 2 shows transceiver 30 of the invention. Transceiver 30 comprises transmission means 32 and calculation means 33. Transmission means 32 transmit code indicating location, for example LAC code, to subscriber terminals 10. Calculation means 33 calculate the number of subscriber terminals 10 from the signal transmitted by subscriber terminals 10. In addition, transceiver 30 comprises antenna 31 using which transceiver 30 transmits for example LAC code to the radio path and receives signal transmitted by subscriber terminal 10. In practice transceiver 30 is e.g. a movable test base station. Transceiver 30 described in the solution of Figure 1 is used for determining the radio network hot spot area. Within the coverage area of base station 20 transceiver 30 is preferably located in the presumed hot spot area or near by. Transmission means 32 of transceiver 30 transmit signalling and LAC code within the coverage area of base station 20. Subscriber terminals 10 receive the signalling and the LAC code transmitted by transmission means 32, subscriber terminals 10 then having a chance to update their location information based on the received LAC code. Subscriber terminals 10 can update location information as transmission means 32 transmit different LAC code compared with the LAC code transmitted by base station 20. When subscriber terminals 10 receive the LAC code of transceiver 30, then subscriber terminals 10 and transceiver 30 are signalling. Calculation means 33 of transceiver 30 calculate the number of subscriber terminals 10 that have tried to update the location position from the signalling between transceiver 30 and subscriber terminal 10. Calculation means 33 calculate the number of subscriber terminals 10 being on standby within the coverage area of subscriber terminals 10. Subscriber terminals 10 on standby are not in speech connection with another subscriber terminal 10. Calculation means 33 also calculate from the signalling a timing advance value on the basis of which calculation means 33 calculate the distance between transceiver 30 and subscriber terminal 10. When transceiver 30 transmits location code from various locations of the radio network, it is easy to define the precise location of the hot spot area based on the obtained distance results. The location information update of subscriber terminals 10 is ended by transmitting a location update reject. If the definition of a hot spot area described above is performed in various locations of the radio network, then the distribution of subscriber terminals 10 in said area can be calculated from the measuring results. If the distribution of subscriber terminals 10 in some area is substantially larger than the capacity of base station 10 located in the area, then the area probably is a hot spot area. A hot spot area is at least formed when a large number of subscriber terminals 10 located in the area establish connection. Base station 20 has not enough capacity in said situation to si multaneously serve all subscriber terminals 10 0 located in the area. Even though the invention has been described above with reference to the example of the accompanying drawings, it is obvious that the invention is not restricted to it but can be modified in various ways within the scope of the inventive idea disclosed in the attached claims.

Claims: CLAIMS 1. A method for determining radio network hot spot area location, the radio network comprising at least one base station (20) and a plurality of subscriber terminals (10), the hot spot area having a concentration of subscriber terminals, in which method the base stations (20) form location areas and transmit location code on the basis of which the subscriber terminals (10) are signalling with the base station (20) and identify the base stations (20) belonging to the same location area, c h a r a c t e r i z e d in that a location code not belonging to the location area is transmitted to the subscriber terminals (10) the number of signalling subscriber terminals (10) is calculated on the basis of said location code and a substantially direct distance that the location code has travelled to the subscriber terminal (10) is calculated using signalling. 2. A method as claimed in claim 1, characterized in that the number of the subscriber terminals (10) signalling on the basis of the location code not belonging to a local area, is calculated in this method. 3. A method as claimed in claim 1, characterized in that the subscriber terminals (10) update information about the base stations located in the local area using location code. 4. A method as claimed in claim 1, characterized in that location code not belonging to the local area is transmitted from different locations for calculating a distribution of the subscriber terminals (10). 5. A method as claimed in claim 1, characterized in that the radio network comprises a transceiver (30) transmitting location code not belonging to the local area. 6. A method as claimed in claim 5, c h a r a c t e r i z e d in that a distance of subscriber terminals (10) signalling with the transceiver (30) transmitting location code not belonging to the local area from said transceiver (30) is calculated from signalling. 7. A method as claimed in claim 1, characterized in that the number of subscriber terminals on standby is calculated in this method. 8. A method as claimed in claim 1, characterized in that the transceiver (30) used in this method is in practice the base station (20). 9. A method as claimed in claim 1, characterized in that the subscriber terminal (10) location is calculated on the basis of the substan tially direct distance that the location code has travelled to the subscriber terminal (10). 10. A method as claimed in claim 1, characterized in that LAC code is used as the location code. 11. A transceiver (30) used in a radio network for determining hot spot area location, the radio network comprising at least one base station (20) and a plurality of subscriber terminals (10), the hot spot area having a concentration of subscriber terminals, and the base stations (20) forming local areas and transmitting location code on the basis of which the subscriber terminals (10) identify the base stations (20) belonging to the local area and are signalling with the base station (20), c h a r a c t e r i z e d in that the transceiver (30) comprises transmission means (32) for transmitting location code not belonging to the local area to the subscriber terminals, calculation means (33) for calculating the number of signalling subscriber terminals (10) and the calculation means (33) for calculating a distance between the transceiver (30) and the subscriber terminals (10) signalling with the transceiver (30). 12. A transceiver (30) as claimed in claim 11, c h a r a c t e r i z e d in that the calculation means (33) calculate the number of those subscriber terminals (10) signalling on the basis of the location code not belonging to the local area. 13. A transceiver (30) as claimed in claim 11, c h a r a c t e r i z e d in that the calculation means (33) determine from signalling a timing advance value on the basis of which a distance between the transceiver (30) and the subscriber terminals (10) is calculated. 14. A transceiver (30) as claimed in claim 11, c h a r a c t e r i z e d in that the calculation means (33) calculate the number of subscriber terminals (10) on standby. 15. A transceiver (30) as claimed in claim 11, c h a r a c t e r i z e d in that the transmission means (32) transmit location code not belonging to the local area from different locations for calculating the distribution of the subscriber terminals (10). 16. A transceiver (30) as claimed in claim 11, c ha r act e r i z e d in that the transceiver (30) is in practice the base station (20). 17. A transceiver (30) as claimed in claim 11, c h a r a c t e r i z e d in that the transmission means (32) transmit LAC code as the location code.

Inventors: PELTOLA HARRI, PELTOLA, HARRI
Applicants: NOKIA TELECOMMUNICATIONS OY, PELTOLA HARRI, PELTOLA, HARRI
Application year: 1998
Main classification: H04Q
IPC codes: H04B7, H04W24