MXPA99008671A - Method and apparatus for performing local traffic measurements in a cellular telephone network - Google Patents

Abstract

A method and apparatus for measuring telephone traffic volume in a cellular telephone system (100) is disclosed. In a first embodiment, a receiver (150) is located at the proposed micro-cell site (120) and measures the strength of signals transmitted by mobile stations (130) to determine the cellular telephone traffic in the proposed micro-cell site (120). In a second embodiment of the present invention, a test base station (500) is located at the proposed micro-cell site (120). A processor (510), communicating with thebase station controller (300) serving the macro-cell (110) surrounding the proposed micro-cell site (120), extracts signal strength measurement reports transmitted to the cellular telephone network (100) from mobile stations (130) in and around the proposed micro-cell site (120). The processor (510) uses the signal strength measurements to calculate the cellular telephone traffic volume in the proposed micro-cell site (120). In a third embodiment of the present invention, a test base station (700) is located at the proposed micro-cell site (120) and is assigned a location area identity different from that of the macro-cells (110) surrounding the proposed micro-cell (120). Mobile stations (130) operating in and around the proposed micro-cell site (120) are required to register in the new location area and transmit a signal strength report which includes the signal strength of the test base station (700). A processor (710) connected to the test base station (700) uses the received signal strength reports to calculate cellular telephone traffic volume in the proposed micro-cell site (120).

Description

METHOD AND APPARATUS FOR CARRYING OUT LOCAL TRAFFIC DETERMINATIONS IN A NETWORK OF CELLULAR TELEPHONES BACKGROUND OF THE INVENTION Technical Field of the Invention The present invention relates generally to a selection of cellular sites in a cellular telephone network, and more particularly, to a method and apparatus for carrying out local traffic determinations at a proposed location of a "conflicting" micro cell. Description of the Related Technique As the use of cellular telephone networks increases, additional capacity must be added to the network to accommodate the increase in cellular telephone traffic. One method to increase the capacity of a cell phone network is to add additional cells to the network. Two methods are available when new cells are added to a cell phone network. In both a system of cell phones that have hierarchical characteristics and one that does not have them, an existing cell is sub divided into two or more smaller micro cells geographically with each micro cell or micro cells being assigned a defined set of radio frequencies to effect wireless communications with mobile stations. The mobile stations are typically served by the cell whose base station transmits the strongest signal measured by the mobile station. In a cell phone system that has hierarchical characteristics new cells can also be added to an existing cell phone network using what is known as hierarchical cell structure. In this aspect, the current cell is sub divided into two or more cells, but, a new micro cell is geographically located within the geographical service area of the current cell or cells it serves. As in the previous approach, the new microcell is assigned a set of radio frequencies to effect communication with the mobile stations. Unlike the previous approach, however, a mobile station is served by the newly added cell when the signal strength of the new cell exceeds the limit level and not when the signal strength of the new cell is strongest. Among other aspects, the limit level typically represents the minimum intensity required for reliable communication. The new cell is typically located in a geographic area that experiences a high density of moving stations that move slowly. The micro cell downloads cell phone traffic from the surrounding macro cells and thereby increases the traffic capacity of the surrounding area. One problem that cell phone network providers face when they add a new cell is to identify and verify an appropriate location to create a new cell to maximize the number of calls diverted to the new cell. To assist in the selection of the site, it is desirable to measure the volume of cell phone traffic in a Global System for Mobile Communications (GSM) in the cell phone network, a ghost-based transmitter called a critical point beacon is located at the proposed site for the cell and transmits a phantom control channel signal. Mobile stations in the nearby area receive the phantom signal, measure the strength of the signal, and report the signal strength in the signal strength reports that are routed routinely to a base station that is currently serving that station mobile in particular. A processor, located at one of the nearby base stations, compares the signal strength measurements of the phantom base station and the nearby base stations to determine the number of mobile stations which measured the signal strength of the phantom base station as than nearby base stations. These mobile stations are candidates to be served by the proposed micro cell and represent the volume of cellular traffic which can be transferred to the micro cell in the cell phone system without hierarchical characteristics. There are several problems with current methods to measure the volume of cell phone traffic. Heap, the current method requires the assignment of a radio frequency to be used by the phantom station. At times, a radio frequency may not be available or may require a reassignment of radio frequencies used by nearby base stations. In addition, the processor which calculates the volume of cellular traffic in the current method to measure the volume of cell phone traffic only intercepts intensity reports from a single base station. Frequently, there are multiple base stations near the proposed micro-cell site and to obtain the volume of cell phone traffic, separate measurements must be carried out at each base station. Therefore, it would be advantageous to design a method and apparatus for determining the volume of cell phone traffic in a cell phone system.

In addition, it would be advantageous to design a method and apparatus for measuring the volume of cell phone traffic which would not require the assignment of radio frequencies. In addition, it would be advantageous to design a method and apparatus for measuring from a single location the cell phone traffic associated with multiple base stations from a single location. SUMMARY OF THE INVENTION The present invention comprises a method and apparatus for measuring the volume of cell phone traffic at a proposed site for micro cell. In a first embodiment of the present invention, a receiver is located at the site proposed for the micro cell and measures the signal strength for transmissions from mobile stations transmitting from locations in and near the proposed micro cell site. A processor that communicates with the receiver records the measurements of signal strength and its duration by extrapolating the volume of cell phone traffic based on these measurements. In a second embodiment of the present invention, a test base station, which transmits a control signal, is located at the proposed site of the micro cell. The mobile stations in and near the proposed micro cell site include a signal strength measurement of the test base station in its routine signal intensity reports which are transmitted to the cellular telephone network. A processor in communication with a base station controller extracts the reports of signal strength communicated to the controller of the base station, and uses the reports to calculate the volume of cell phone traffic in the proposed site of the micro cell. The processor of the present invention may be separate from the controller of the base station, or alternatively, the controller of the base station may be programmed to execute the functionality of the processor thereby eliminating the need for a processor. In a third embodiment of the present invention, a test base station is located at the site proposed for the micro cell and a different location area is assigned to any of the macro cells surrounding it. It is also possible that there are no cells surrounding the proposed cell site, in which case, the proposed cell site will provide cell phone service to a geographic area that is not currently served. The inactive mobile stations that operate in and near the proposed micro cell site are required to register at the new location of the test base station.

The inactive mobile stations transmit a location update request to the test base station followed by a signal strength report which includes a signal strength measured at the base station. The test base station delays the sending of a rejection to the location update request from the mobile station in order to ensure that at least one report of signal strength is transmitted to the base test station by the mobile station. The purpose of this mode is to measure the number of inactive mobile stations in the area of interest. By using previously compiled statistics that show the relationship between the number of inactive mobile stations and active mobile stations, it is possible to estimate the number of active mobiles and with it the amount of traffic in the area. BRIEF DESCRIPTION OF THE DRAWINGS In order to better understand the present invention, reference is made to the following detailed description taken in conjunction with the accompanying drawings in which: FIGURE 1 illustrates the functional block diagram of a first embodiment of the present invention deployed with a single macro cell that uses signal strength measurements to measure the volume of cell phone traffic; FIGURE 2 illustrates a portion of a cell phone transmission divided into discrete time segments; FIGURE 3 illustrates a functional block diagram of a first embodiment of the present invention deployed in a location surrounded by a plurality of macro cells; FIGURE 4 illustrates a flow chart for a first embodiment of the present invention; FIGURE 5 illustrates a functional block diagram of a second embodiment of the present invention wherein measurements of signal strength are taken from multiple macro cells; FIGURE ß illustrates a flow chart of a second embodiment of the present invention; FIGURE 7 illustrates a functional block diagram of a third embodiment of the present invention wherein mobile stations are forced to register at a new area location; and FIGURE 8 illustrates a flow diagram of a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION Although the present invention is described as being implemented in the Global System for Global Communications (GSM) standard, it is understood that the invention is capable of being implemented in other cell phone system protocols. With reference to FIGURE 1, a cellular telephone network 100 including a base station 140 for providing cellular telephone service to mobile stations 130 operating within a macro cell 110 is illustrated. To increase the capacity of the cellular telephone within the micro cell 110, a micro cell 120 known as a hot zone can be created. In a cell phone system that does not have hierarchical characteristics, the cell phone calls are sent from the base station 140 serving the macro cell 110 to a base station (not shown), which will serve the proposed micro cell 120, based on a comparison between the signal intensities of the macro cell 110 and the micro cell 120. Although other factors are taken into consideration, a delivery typically occurs when the signal strength of the proposed base station (not shown) is stronger than the current 110 cell macro. In a cell phone system with hierarchical characteristics, cell phone calls are typically delivered from the base station 140 serving the macro cell 110 to the base station (not shown), which will serve the proposed micro cell 120, when the signal strength of the base station (not shown) is above a minimum threshold level. Among other details, the threshold level typically represents the minimum signal strength required to provide reliable communication between the proposed base station (not shown) which will serve the micro cell 120 and the mobile station 130. (The threshold level is also set high enough to eliminate co-channel interference caused by the use of the same carrier frequency used in a distant cell). The micro cell 120, however, has a relatively limited coverage area compared to the macro cell 110, and therefore, the objective is to locate the micro cell 120 in a location where the greatest amount of traffic can be captured. To determine an optimal location for the location of the micro cell 120, it is desirable to take volume measurements of cell phone traffic at several proposed sites. Although in the actual operation both the downlink signal strength of the base station (not shown) of the proposed micro cell 120 and the uplink signal strength of the mobile stations 130 are used to determine when the deliveries occur, a The first embodiment of the present invention uses instead only the signal strength of the mobile stations 130 to calculate cell phone traffic. In the first embodiment of the present invention, a receiver 150 capable of receiving one or more radio cellular telephone frequencies allocated for use by the base station 140 is placed in the proposed site of the micro cell 120. The receiver 150 monitors one or more of the radio frequencies and takes measurements of signal strength of transmissions of the mobile stations 130. A processor 160 in communication with the receiver 150 records the measurements of signal strength and the duration of the measurement. As will be described, the processor 160 will process the recorded data to determine the volume of cell phone traffic at the proposed site of the micro cell 120. Further reference to FIGURE 2 illustrates a portion of a cell phone transmission 200 divided into discrete segments of time 210. Although the receiver 150 can make continuous measurements of signal strength of the transmissions 200 of the mobile stations 130, the preferred embodiment incorporates the discrete sampling of the cell phone transmission 200. The receiver 150 takes continuous measurements of signal strength of each time slot 210 and the processor 160 records the measurements and assigns the measurements a duration equal to the duration of the time slot 210. After taking measurements over a period of time, the receiver 150 and the processor 160 obtain a number sample statistically enough to allow the processor to extrapolate the traffic volume of t cellular phone of the registered data. To extrapolate the volume of cell phone traffic, the processor 160 divides the total number of samples, where the measured signal strength is greater than the threshold level, by the total number of samples taken arriving in a fractional time that the signal strength above the threshold level. In this and in all modalities, the frequencies which are to be monitored are selected from frequencies which are not used for the purpose of sampling. Otherwise, the extrapolation process must first eliminate those time segments which are assigned for signaling purposes and do not represent volume of traffic. If the receiver 150 took only measurements on a single frequency, the cell phone traffic volume is calculated by multiplying the fractional time previously calculated by the total of radio frequencies assigned to the base station 140. If, on the other hand, the receiver monitored more of a radio frequency, the volume of cell phone traffic is calculated first by dividing the fractional time previously calculated by the number of radio frequencies monitored and multiplied by the total number of radio frequencies assigned to the base station 140. For several reasons, including a In order to extend the life of the battery and reduce interference, the cellular telephone network 100 may vary the transmission output power of the mobile stations 130. In order that the first embodiment of the present invention makes accurate measurements of the volume of cell phone traffic each mobile station 130 needs to transmit at the same pot level ncia. Therefore, the first embodiment of the present invention provides for the cellular telephone network 100 to disable the power regulation of the mobile stations 130 within the site of the macro cell 110. With further reference to FIGURE 3, the proposed site of the micro cell 120 of FIGURE 2 surrounded by a plurality of macro cells 110 currently serving the geographic region of the proposed site of the micro cell 120. Each of the macro cells 110 is served by a corresponding base station 140 which communicates with the cellular telephone network 100 by means of a common base station controllers 300. In a manner consistent with that described in FIGURE 1, the receiver 150 monitors one or more radio frequencies assigned to one or more of the base stations 140. As with the description of FIGURE 1, the power regulation of the base stations 130 is disabled. The receiver 150 measures the signal strength of each time slot 210 and the processor 160 records these measurements and their duration. The volume of cell phone traffic is extrapolated from the data recorded by the processor 160. The volume of cell phone traffic is determined first by calculating the first fractional time the measured signal strength was greater than the threshold level. To calculate the fractional time, the processor divides the total number of samples, wherein the measured signal strength of the received signal is greater than the threshold level, by the total number of samples taken. The receiver 150 took measurements on a single radio frequency, the volume of cell phone traffic is calculated by multiplying the fractional time previously calculated by the total number of radio frequencies assigned to the base station 140 using the radio frequency. If, on the other hand, the receiver monitored more than one radio frequency, the volume of cell phone traffic is calculated first by dividing the fractional time previously calculated by the number of radio frequencies monitored and multiplying by the total number of radio frequencies assigned to the plurality of base stations 140. With further reference to FIGURE 4, a flow diagram of the first embodiment of the present invention is illustrated. Before taking the measurements of signal strength, the power regulation of the mobile stations 130 is disabled (step 400). In this step, the cell phone network 100 directs the base station 140 to disable power regulation. Once the power regulation has been disabled, the receiver 150 measures the signal strength and the duration (step 410), of the transmissions 200 of the mobile stations 130. The receiver 150 when taking the measurements of signal strength, the processor 160 records the data and extrapolates the volume of cell phone traffic (step 420). With further reference to FIGURE 5, a second embodiment of the present invention is illustrated. A cell phone network 100 includes a plurality of base stations 140 which provide cell phone service in the corresponding macro cells 110. Each of the base stations 140 is connected to the cellular telephone network 100 by means of a common base station controller 300. In the second embodiment of the present invention, a test base station 500 is located at the macro site proposed cell 120. The test base station 500 is limited in its functionality but to a minimum, it includes a transmitter to transmit a control channel. The output power and transmitter of the test base station 500 is selected to obtain the same coverage of the proposed micro cell 120. The test base station 500 is intended only to transmit a control frequency and not to facilitate communication between the mobile stations 130 and the cellular telephone network 100, and therefore, communication between the test base station 500 and the cellular telephone network 100 is not necessary. Mobile stations, when moving through the geographic service area of a cellular telephone network, are provided with a frequency list of location control containing a list of radio frequencies representing cell sites whose transmission channels control the mobile stations which requires monitoring. These cells are cells that surround the mobile station at its current location which can potentially be a candidate to serve the mobile station. The mobile station is required to measure the signal strength of each base station transmitter represented by the frequencies included in the list and report the six strongest signal strength measurements to the base station serving the mobile station that is serving to the mobile station. The signal strength reports are communicated to the base station controller that connects the service base station to the cellular telephone network and are used to determine when the delivery of the base station to which it is currently serving the mobile station to. another base station. In the second embodiment of the present invention, a test base station 500 is established within the cellular telephone network 500. Although the test base station 500 is not communicating with the cellular telephone network 100, the test base station 500 includes the transmission of the control channel, assigned to the test base station 500 in the list of control transmission assignments which are provided to the mobile stations 130 served by the plurality of macro cells 110 surrounding the proposed micro cell 120 Since the transmission of the control channel of the test base station 500 is included in the list of control channel assignments given to the mobile stations 130 served by the plurality of macro cells 110, the mobile stations 130 are required to take measurements of signal strength of the test base station 500 and include the measurements in the report of the signal strength measurement l sent to the cell phone network assuming that the test base station 500 is among the six strongest signals. Every 0.48 seconds, signal strength reports are communicated to the base station controller 300 by means of the base station 140 that is serving the mobile station 130. To prevent the mobile stations 130 from attempting to access the test base station 500, a Cell blocking indicator associated with the test base station 500 is fixed. Setting this cell blocking indicator, the mobile stations are prevented from remaining in the cell, thereby disabling access to the test base station 500. Alternatively, the vital information necessary for the mobile stations to remain in the base station can be omitted from the transmissions of the mobile station. the test base station 500, thereby, making the test base station 500 unsuitable for permanence. Using any approach, therefore, the mobile stations 130 surrounding the test base station 500 are required to report the signal strength of the test base station 500 in their ordinary signal strength reports, but are prevented from accessing them. the test base station 500. There are several methods to identify the signal strength of the base station contained in the signal strength reports sent to the controller of the base station 300. For example, the identity key of the base station of the Test base station 500 can be used. In the preferred embodiment, however, the test base station 500 is excluded from the list of neighboring cells and is therefore identified as an unidentified neighbor. In the second embodiment of the present invention, a processor 510 communicates with the base station controller 300 and extracts all reports of signal strength containing an unidentified neighbor. As indicated above, the processor 510 can be removed and the controller of the base station 300 can carry out the functionality carried out in another way by the processor 510.

The processor 150 records the signal strength of the test base station 500, identified as an unidentified neighbor, and the signal strength of the base stations. 140 After extracting and recording the signal strength reports over a period of time, the Processor 510 obtains a statistically sufficient number of data to enable processor 510 to calculate the volume of cellular traffic at the proposed site of microcell 120. There are two methods for calculating cell phone traffic volume based on the data collected depending on yes the cell phone system employs hierarchical cells. In a cell phone system that does not employ hierarchical cells, a decision to deliver a mobile station 130 to the base station (not shown) of the proposed site of the micro cell 120 is based on the comparison of the signal strength offered by the cells . Also, since mobile stations 130 are required to transmit a signal strength report every 0.48 seconds, each signal strength report represents signal strength over a period of 0.48 seconds. Therefore, to calculate the volume of cell phone traffic in a cell phone system that does not employ hierarchical cells, the processor 510 multiplies the total number of signal strength reports, wherein the signal strength of the base station of test 500 exceeds the signal strength of the plurality of base stations 140, by 0.48 seconds and divides the product by the period of time over which said measurements were taken. To calculate the volume of cell phone traffic in a cell phone system containing hierarchical cells, the processor 510 multiplies the total number of signal strength reports, wherein the signal strength of the 500 test base station exceeds the level threshold, for 0.48 seconds and divide the product by the period of time over which the measurements were taken. With further reference to FIGURE 6, a flow diagram for the second embodiment of the invention is illustrated. The test base station 500 (step 600) within the cellular telephone network 100. This step further includes the steps of assigning a radio frequency (step 610), indicating to the mobile stations 130 to include the test base station 500 in the signal strength reports (step 620), and prohibiting access to the test base station (step 630) by the mobile stations 130. The radio frequency assigned to the test base station 500 in step 610 is used by the test base station 500 to transmit the transmission control channel c. In step 620, the mobile stations 130 are required to include measurements of the test base station 500 in the signal strength reports including the transmission of the control channel of the base station 500 in the control channel transmission list provided to mobile stations 130 served by the plurality of macro cells 110. In step 630, mobile stations 130 are forbidden from accessing the test base station 500 by setting a cell blocking pointer or by omitting critical information in the transmission of the cell. control channel of the test base station 500. After the test base station 500 is established in the cellular telephone network 100, the test base station 500 transmits a control channel (step 640). The processor 510 monitors the signal strength reports (step 650) transmitted by the mobile stations 130 to the respective service base stations 140 which communicate the signal strength report to the base station controller 300. The monitoring of the reports of signal strength in step 650 includes the steps for extracting signal strength reports (step 660) from the cellular telephone network 100 and recording the signal strength reports (step 670). In step 660 the signal strength reports containing signal strength measurements of the test base station 500 are identified by omitting the test cell base station 500 from the neighboring cell thereby causing the signal strength report to include a measurement of signal strength for an unidentified neighbor. The processor 510 extracts all the transmitted signal strength reports to the base station controller 300 that contain a record of an unidentified neighbor. Since the plurality of macro cells 110 communicate signal strength reports to a common base station controller 300, the processor 510 can extract reports of signal strength from all the macro cells 110 surrounding the proposed micro cell 120 site. extract the signal strength reports steps 660 from the base station controller 300, the processor 510 records the signal strength measurements included in the report for all base stations 140 surrounding the proposed micro cell site 120 and the intensity signal of the base station 500. After extracting and recording the reports of signal strength over a period of time providing a statistically significant number of data, the processor 510 calculates the volume of cell phone traffic (step 690). In a cell phone system that does not employ hierarchical cells, the processor 510 multiplies the total number of signal strength reports, wherein the signal strength of the test base station 500 exceeds the signal strength of the base stations 140, for 0.48 seconds and divide the product by the period of time over which the measurements were taken to obtain the volume of cell phone traffic. In a hierarchical cell phone system the processor 510 multiplies the total number of signal strength reports, wherein the signal strength of the test base station 500 exceeds the threshold level, by 0.48 seconds and divides the product by the period of time over which the measurements were taken to obtain the volume of cell phone traffic. With further reference to FIGURE 7 a third embodiment of the present invention is illustrated. As with the second embodiment of the present invention, a test base station 700 transmits a control frequency channel at a frequency assigned to the test base station 700. Not as in the second embodiment of the present invention, however, the microcell Proposal 120 is fixed at a new location through the use of a different location area identity of the macro cells 110 that surround it. The mobile station 120 operating in idle mode near the proposed micro cell 120 is required to register with the test base station 700 due to a change in location area. To register, the inactive mobile stations 130 make a location update request to the test base station 700 and transmit a signal strength report which includes the measured signal strength of the test base station 700. The base station of Test 700 delays the response of the update request until the mobile station 130 transmits a signal strength measurement report. The test base station 700 responds with a rejection of the update request by the mobile station 130 thereby causing the mobile station 130 to select another base station to remain there. The rejection ensures that no mobile station 130 is cut off from the cell phone system 100 due to an attempt to remain at the test base station 700. A processor 710, communicating with the test base station 700, records the signal intensity reports. transmitted to the test base station 700 and calculates the volume of cell phone traffic in the proposed micro cell 120. To calculate the cell phone traffic volume within the proposed micro cell 120 the 710 processor compares the signal strength of the test base station 700 against the macro cells 110 that surround it in the cell phone system that does not employ hierarchical cells respectively to determine the number of mobile station 130 which have been authorized to remain in the test base station 700. As in the previous mode, the 700 test base station will serve the mobile station when the test base station ba 700 have a stronger signal respectively. To calculate the volume of cell phone traffic using this modality it is necessary to know the ratio between active mobile station and inactive mobile station. Using this data and the data taken showing the inactive mobile station number which would have been allowed to remain in the 700 test base station, the processor 710 extrapolates the number of active mobile stations which represent the volume of cell phone traffic at the site of the proposed micro cell 120. With further reference to FIGURE 8, a flowchart for the third embodiment of the cell is illustrated. the present invention. A test base station 700, including a transmitter and a receiver, is located at the site of the proposed micro cell 120 (step 800). The test base station 700 is assigned to a new location (step 810) which is different from the location assigned to the plurality of macro cells 110 surrounding the proposed micro cell 120. The test base station 700 transmits a channel of control in radio frequencies assigned to the test base station 700 (step 820). The inactive mobile stations 130 traveling near the site of the proposed micro cell 120 are required to be registered with the test base station 700 assigned to the new location. The mobile stations 130 also transmit a signal strength report to the test base station 700 which is received by the test base station 700 (step 830). The test base station 700 transmits a delayed rejection response (step 840) to the mobile stations 130 thereby prohibiting the mobile station 130 from remaining in the test base station 700. A processor 710, in communication with the base station of Test 700, records the signal strength measurements and extrapolates the volume of cell phone traffic (step 850). The processor 710 calculates the number of idle mobile stations which would remain in the test base station 700 if they were allowed by comparing the signal strength of the test base station 700 against the signal strength of the macro cells 110 surrounding it. a cell phone system that does not employ hierarchical cells or against the threshold level in a cell phone system that employs hierarchical cells. To calculate the volume of cell phone traffic using this modality, the statistical data that measure the ratio between inactive mobile stations and inactive mobile stations is necessary. Using this data and the data generated showing the number of inactive mobile stations which would have remained at the test base station 700 if allowed, the 710 processor extrapolates the number of active mobile stations which represent the volume of cell phone traffic at the site of the proposed micro cell 120. The third embodiment of the present invention, if deployed in a cell phone system using the Global System for Global communications, operates only in an area that has a majority of Phase mobile stations. 2 as compared to Phase 1 mobile stations. Not like Phase 2 mobile stations which look for an alternative cell (location area) to stay when they are rejected from a location area, in turn the mobile Phase 1 stations in they place themselves in a state of limited service. While in this state, the mobile station is not able to make a telephone call and remains in this state until it leaves the transmitter area and enters a new location area. Although the preferred embodiments of the method and apparatus of the present invention have been illustrated in the appended Drawings and described in the above Detailed Description, it is understood that the invention is not limited to the disclosed embodiments, but is capable of numerous accommodations, modifications and modifications. substitutions without departing from the spirit of the invention as defined in the following Claims.

Claims (1)

1. CLAIMS: A method for measuring the volume of cell phone traffic at a proposed cell site of a cellular telephone network comprising the steps of: disabling the power regulation of the mobile station within the proposed cell site; measuring the signal strength and transmission duration of the mobile station at least one radio frequency used by a base station serving the proposed cell site; and extrapolating the volume of cell phone traffic based on the signal strengths, the duration of the signal and the total number of radio frequencies used by the base station currently serving the proposed cell site. The method indicated in Claim 1, wherein the step of measuring signal strength and duration comprises sampling the signal strength of each time segment transmitted by the mobile station within the proposed site of the cell. The method indicated in Claim 2, wherein the step of extrapolating the cellular telephone traffic volume comprises the steps of: dividing the number of sampled time segments, wherein the signal intensity exceeds the desired threshold level, between the product of the total number of time segments sampled by the number of radio frequencies measured to calculate a fractional time that exceeds the sampled signal of the desired threshold level; and multiply the fractional time by the total number of radio frequencies used by the base station serving the location of the proposed cell. A method for measuring the volume of traffic at a proposed cell site of a cellular telephone network comprising the steps of: disabling the power regulation of the mobile station within the proposed cell site; measuring the signal strength and duration of cell phone transmission at least one radio frequency used by a base station serving the proposed cell site; and extrapolating the volume of cell phone traffic based on the signal strengths, the duration of the signal and the total number of radio frequencies used by the base station currently serving the proposed cell site. The method indicated in Claim 4, wherein the step of measuring the signal strength and duration comprises sampling the signal strength of each time segment transmitted by the mobile station within the proposed cell site. The method indicated in Claim 4, wherein the step of extrapolating the cell phone traffic volume comprises the steps of: dividing the number of time segments sampled, where the signal strength exceeds the desired level, between the product of the total number of time segments sampled by the number of radio frequencies measured to calculate a fractional time that exceeds the sampled signal of the desired threshold level; and multiply the fractional time by the total number of radio frequencies used by the base station serving the location of the proposed cell. An apparatus for measuring the volume of cellular telephone traffic at a proposed cell site of a cellular telephone network comprising: a receiver located at the proposed cell site for measuring the signal strength and duration of transmissions of a mobile station; and a processor, communicating with the receiver to extrapolate the volume of cellular telephone traffic based on signal strengths, signal durations and the total number of radio frequencies used collectively by the base station serving the proposed cell site . A method for measuring the volume of cellular telephone traffic at a proposed site of a hierarchical cellular telephone network comprising the steps of: establishing a test base station within the cellular telephone network; transmit radio frequencies assigned from the base test station located at the proposed cell site; monitoring, over a period of time, the number of signal strength reports transmitted by the mobile station to the cellular telephone network containing measurements of signal strength to the base station; and calculating the volume of cell phone traffic based on the total number of signal strength reports containing signal strength measurements of the test base station where the intensity exceeds a desired threshold level, the time period monitored, and a period of time representing each report of signal strength. The method indicated in Claim 8, wherein the step of establishing a test base station further includes the steps of: allocating radio frequencies for use by the test base station; instruct mobile stations to include the test base station in the signal strength reports; and prohibit mobile stations from trying to access the base test station. The method indicated in Claim 8, wherein the step of establishing a test base station further includes the steps of: allocating radio frequencies for transmission by the test base station; include the test base station in the control channel allocation list of cell sites surrounding the proposed cell site thereby requiring that the mobile station include measured signal strengths of the test base station in the intensity reports of signal; and setting a cell bar pointer to prohibit the mobile station from attempting to access the test base station. The method indicated in Claim 8, wherein the step of transmitting assigned radio frequencies comprises the transmission of a transmission control channel. The method indicated in Claim 8, wherein the step of monitoring the number of signal strength reports transmitted by the mobile station includes the steps of: omitting the test base station from the neighboring cell lists to identify the reports of signal intensity as containing an unidentified neighbor; extract from the cell phone network, all reports of signal strength identified as an unidentified neighbor; and recording the number of signal strength reports containing a measurement of signal strength for the unidentified neighbor in which the intensity exceeds a threshold level. The method indicated in Claim 11, wherein the step of extracting the signal strength reports from a cellular telephone network includes extracting the signal strength reports from at least one base station controller in communication with at least one base station currently serving the proposed cell site. The method indicated in Claim 8, wherein the step of calculating the cellular telephone traffic volume includes the steps of: multiplying the total number of signal intensity reports containing a signal strength measurement of the base station of test, wherein the signal strength of the test base station exceeds a desired threshold level, for the period of time that each signal strength report represents to obtain a duration of time when the signal strength of the base station of test exceeds the threshold level; and divide the duration of time by the monitored period of time. . An apparatus for measuring the volume of cellular telephone traffic at a proposed cell site of a hierarchical cellular telephone network comprising: a radio transmitter located at the proposed cell site for transmitting a transmission control channel; at least one base station for receiving reports of mobile station signal strength; and a processor for monitoring the signal strength reports received by the base station, and in addition, for calculating the volume of cell phone traffic. . An apparatus for measuring the volume of cellular telephone traffic at a proposed cell site of a hierarchical cellular telephone network comprising: a radio transmitter located at the proposed cell site to transmit a transmission control channel; at least one base station for receiving reports of mobile station signal strength; and a processor for monitoring the signal strength reports received by the base station, and in addition, for calculating the volume of cell phone traffic. 17. A method for measuring the volume of cellular telephone traffic at a proposed cell site of a cellular telephone network comprising the steps of: establishing a test base station within the cellular telephone network; transmitting assigned radio frequencies from the test base station located at the proposed cell site; monitoring, over a period of time, the number of signal strength reports transmitted by the mobile station to the cellular telephone network containing a signal strength measurement of the test base station; extracting the signal strength reports from at least one base station controller in communication with at least one base station serving the proposed cell site; and calculating the volume of cell phone traffic based on the total number of intensity reports where the signal strength of the test base station exceeds the signal strength measurement of a base station currently serving the mobile station, the period of monitored time, and a period of time representing each report of signal strength. . The method indicated in Claim 17, wherein the step of establishing a test base station further includes the steps of: allocating radio frequencies for use by the test base station; instruct the mobile station to include the test base station in the signal strength reports; and prohibit the mobile station from attempting to access the test base station. . The method indicated in Claim 17, wherein the step of establishing a test base station further includes the steps of: allocating radio frequencies for transmission by the test base station; include the test base station in the control channel allocation list of cell sites surrounding the proposed cell site thereby requiring that the mobile station include measured signal strengths of the test base station in the intensity reports of signal; and setting a cell bar pointer to prohibit the mobile station from attempting access to the test base station. 20. The method indicated in Claim 17, wherein the method of transmitting assigned radio frequencies comprises transmitting a transmission control channel. The method indicated in Claim 17, wherein the step of monitoring the number of signal strength reports transmitted by the mobile station includes the steps of: omitting the test base station from the neighboring cell lists to identify the reports of signal intensity as containing an unidentified neighbor; extract from the cell phone network, all reports of signal strength identified as an unidentified neighbor; and recording the number of signal strength reports containing a measurement of signal strength for the unidentified neighbor in which the intensity exceeds a threshold level of a base station serving the mobile station. 22. The method indicated in Claim 17, wherein the step of calculating cell phone traffic volume includes the steps of: multiplying the total number of signal intensity reports, wherein the signal strength of the base station of test exceeds the signal strength of the base station serving the mobile station, for the period of time representing each report of signal strength to obtain a duration of time when the signal strength of the test base station exceeds the intensity of the signal. signal from the base station serving the mobile station; and divide the time duration of the monitored time periods. 3. An apparatus for measuring the volume of cell phone traffic at a proposed cell site of a cellular telephone network comprising: a radio transmitter located at the proposed cell site for transmitting a transmission control channel; at least one base station for receiving reports of mobile station signal strength; and a processor for monitoring the signal strength reports received by the base station, and in addition, for calculating the volume of cell phone traffic. . A method for measuring the volume of cellular telephone traffic at a proposed cell site of a cellular telephone network comprising the steps of: locating a test base station within a cellular telephone network; assigning a proposed cell site a new location area identity different from the cell sites surrounding the proposed cell site thereby forcing the mobile station to register with the test base station; transmitting a transmission control channel from the test base station; receive location update requests and signal strength reports transmitted by the inactive mobile station; respond with a rejection of the location update request, the response being delayed until the signal strength measurement has been received by the test base station; and multiplying the number of signal strength reports transmitted to the test base station, where the intensity of the test base station exceeds a desired threshold level, for a statistical reason of the active mobile station to determine the traffic volume of cell phone. 25. The method indicated in Claim 24, wherein the base station is disconnected from the cellular telephone network. 26. A method for measuring the volume of cellular telephone traffic at a proposed cell site of a cellular telephone network comprising the steps of: locating a test base station within a cellular telephone network; assigning a proposed cell site a new location area identity different from the cell sites surrounding the proposed cell site thereby forcing the mobile station to register with the test base station; transmitting a transmission control channel from the test base station; receive location update requests and signal strength reports transmitted by the inactive mobile station; respond with a rejection of the location update request, the response being delayed until the signal strength measurement has been received by the test base station; and multiplying the number of signal strength reports transmitted to the test base station, where the intensity of the test base station exceeds a desired threshold level, for a statistical reason of the active mobile station to determine the traffic volume of cell phone. . The method indicated in Claim 26, wherein the base station is disconnected from the cellular telephone network. . Apparatus for measuring the volume of cell phone traffic at a proposed cell site of a cellular telephone network comprising: a test base station assigned to a defined location area and located at the proposed cell site, the base station for transmitting a transmit control channel and receiving the location update requests and the signal strength reports, the base station further to transmit a rejection in response to the reception of the location update request and the signal strength report; and a processor communicating with the base station, the processor records the signal strength reports received by the test base station and further calculates the volume of cell phone traffic. SUMMARY OF THE INVENTION A method and apparatus for measuring the volume of telephone traffic in a cell phone system is presented (100) In a first embodiment, a receiver (150) is located at the proposed site of the micro cell (120) and measures the intensity of the signals transmitted by mobile stations (130) to determine cell phone traffic at the proposed cell site (120). In a second embodiment of the present invention, a test base station (500) is located at the proposed cell site (120). A processor (510), which communicates with the base station controller (300) serving the micro cell (110) surrounding the proposed cell site (120), extracts reports of signal strength measurements transmitted to the network of cell phone (100) of the mobile station (130) in and around the proposed micro cell site (120). The processor (510) uses the signal strength measurements to calculate the cell phone traffic volume at the proposed cell site (120). In a third embodiment of the present invention, a test base station (700) is located at the proposed cell site (120) and is assigned an area location identity different from the macro cells (110) surrounding the proposed site of micro cell (120). It is required that mobile stations (130) operating in and around the proposed micro-cell site (120) be registered in the new area location and transmit a signal strength report which includes a signal strength from the base station ( 700). A processor (710) connected to the test base station (700) uses the reports of the received signal strength to calculate the volume of cell phone traffic at the proposed site of the micro cell (120).