Load monitoring and management in a cdma wireless communication system

BACKGROUND OF THE INVENTION

I. Field of the Invention

The present invention generally relates to wireless communications. Specifically, the present invention is directed to a novel and improved System and method for monitoring and management of the load or load a wireless code division multiple access communication system or CDMA communication system (CDMA = Code Division Multiple Access) directed.

II. Description of Related Art

On in wireless code division multiple access communication share several communication devices or devices a broadband frequency channel, wherein each communication device a different pseudo-noise spreading and PN spreading (PN = pseudo-noise) begins. In a typical CDMA wireless communication system is a first frequency band for Forward channel communications (Base station to mobile station), while a second frequency band, is different from the first frequency band for reverse channel communications (Mobile station to base station) is used. An example of a such a system is given in <patcit><text>US Patent No. 4,901,307</text></patcit>, Entitled "SPREAD SPECTRUM MULTIPLE ACCESS COMMUNICATION SYSTEM USING SATELLITE OR TERRESTRIAL REPEATER ", issued February 13, 1990, which the Applicant is assigned to the present invention.

Of the Process of power control is the concept of maximizing the system capacity in a CDMA wireless communication system as described above is fundamental. The output power of subscriber units must are controlled to ensure that sufficient signal strength at the base station is received, and to maintain a good audio quality, while the potential for Interference is minimized. Since a CDMA wideband channel in each Cell is re-used, is the self-interference caused by other users of the same cell is caused, and the interference, caused by users in other cells of the most restrictive factor the system capacity. Due to fading and other channel impairments, is the maximum capacity achieved when the signal-to-noise ratio (SNR = signal-to-noise ratio) for each user, on average, at the minimum point is needed, to an "acceptable" channel performance to support. Since noise spectral density almost exclusively by the interference other user generated must All signals in the CDMA receiver the same average power arrive. In the mobile Propagation environment this is achieved by providing a dynamic achieved power control of the mobile station transceiver. Power control protects against changes in the system load or -auslastung, blocking (jamming), slow and rapid changes the channel states and against sudden Improvements or deteriorations in the channel (shadowing).

power control the transmitter of the mobile station consists of two elements: open loop estimation and Control estimate Transmit power by the mobile station and closed-loop correction or Control correction of the error in this estimate by the base station. at the open-loop power control, each mobile station estimates the total received power on the assigned CDMA frequency channel. Based on this measurement and a correction by the base station is provided, which transmitted from the mobile station power is adjusted so that they matched with the estimated path loss is so that they at the base station with a predetermined level arrives. All mobile stations use the same process and reach the same average power the base station. Uncontrolled or uncontrolled differences in the forward and reverse channels, such as mutual Fading (fading opposite), the and due to the frequency difference Nonconformities may occur in the receive and transmit chains of the mobile station, can are not appreciated by the mobile unit.

Around to reduce these residual errors, corrected each mobile station their Transmit power with closed loop power control information, by the the base station inserted low rate data in any forward traffic channel is supplied. The base station derives the correction information by monitoring the rear ward CDMA channel quality of each Mobile station, compares this measurement to a threshold and calls either an increase or a reduction depending from to found. In this way, the base station maintains each reverse channel, and thus all reverse channels, with the minimum received power needed to provide acceptable provide performance. An example of a communication system, employing the above-described open-loop and closed-loop power control method, is shown in <patcit><text>US Patent No. 5,056,109</text></patcit> "METHOD AND FOR CONTROLLING TRANSMISSION POWER IN appartus A CDMA CELLULAR MOBILE TELEPHONE SYSTEM " assigned to the assignee of the present invention.

&lt;?page 3?&gt;

In a wireless CDMA communication system as described above is, is a predetermined number of radio frequency resources, such as Transceivers and channel modulators / demodulators (modems) with any Base station arranged. The number of a particular base station allocated resources is a function of the anticipated traffic loading conditions. For example, a system in a rural Area only an omni-directional antenna at each base station have sufficient and Channel modems to support simultaneous calls. On the other side, a base station in a dense urban be co-located with other base stations area, where each having several highly directional antennas, and enough modems forty or to handle more simultaneous calls. These denser urban Areas is the cell site capacity particularly valuable and must be closely monitored be managed and to the most efficient allocation of limited Resources provide while maintaining acceptable quality of Communications.

Sector / cell load the ratio the actual Number of users in the sector to the maximum theoretical number, support the sector can. This ratio is proportional to the total interference of the recipient Sector / cell is measured. The maximum number of users, can support the sector / cell is a function of the aggregate signal-to-noise ratio, voice activity, and Interference from other cells. The individual signal-to-noise ratio of a Subscriber unit depends the speed of the subscriber unit, the radio frequency propagation environment and the number of users into the system. The interference of other cells depends on the number of users in these cells, radio frequency propagation losses and the way on how the users are distributed. Typical calculations capacity going from a same signal-to-noise ratio for all the users and the same nominal values voice activity and interference from other cells. In actual systems changes the signal-to-noise ratio, however, from user to user and frequency reuse efficiency varies from sector to sector. Thus, there is a need for a continuous monitoring the load or utilization of a sector or a cell.

A conventional Art, cell site loading conditions to monitor is that a person, usually a network engineer or technicians that of a wireless communication service provider is hired, moves from cell to cell and thereby performs load condition readings using specially designed and expensive test equipment. The Recorded data is then sent to a central processing facility for the subsequent processing and analysis returned. Significant disadvantages this method are that the data can not be evaluated in real-time can be, and that due to the propagation effects between the base station and the measuring equipment significant errors are introduced. Thus, this monitoring method only looks a rough estimate the cell site loading conditions ago, and can only be used on a time-delayed manner to take corrective action, such as by reassigning resources for the future. Allows the service provider is not some sort of real-time actions make to the load conditions and to improve their effect on system performance. moreover a person has to move sequentially to each site, thereby a discontinuous or interrupted "hit-or-miss" case estimate the peak load conditions and the resulting system performance will be provided, depending on whether the visit with the actual (Rather than assumed) peak usage times coincide.

A another possible Type of monitoring Cell site loading conditions is to access the performance data, by the base station itself is recorded, or by the base station controller or the base station controller. This makes it necessary, however, that scarce base station processing resources used are to collect and retrieve the data. In addition, this suffers Type of monitoring in the aforementioned Non-real-time Nachverarbeitungsproblemen. Finally, it also makes it necessary that a person successively each cell site visited, to retrieve the data.

It is a simple and accurate remote real-time load monitoring information and management needs, the access to neither of the base station more of the base station controller logged data makes it necessary, and thus does not affect the performance of the processor.

the Document of the prior art <patcit><text>US 5,367,533</text></patcit> disclosed a spread spectrum CDMA communications system with dynamic allocation for at least partial geographical superimposing and frequency superimposing a radio relay system.

SUMMARY OF THE INVENTION

The Invention according to the appended claims, a new and improved system, a monitoring device and a method for monitoring and management of load conditions in a CDMA wireless communication&lt;?page 4?&gt;system. The system and method utilize forward link data collected by the mobile station will be collected to determine the effect of load or utilization to estimate the system performance. Among Having regard to the effect of loading on system performance can measures be taken to limit access to the system, or to allocate more resources to a system performance degradation to prevent.

the System includes a load monitoring device on, such as a CDMA mobile station with a data recording or data acquisition and processing device is connected, such as a Diagnostic monitoring device, or a modified mobile station which is capable of self- perform Datenaufzeichungs- and processing functions. The monitoring device is placed within the service area of ​​a base station. The monitoring device periodically initiates a call, in the normal way a traffic channel assigned and takes the following data: 1) the reverse link transmission power the mobile station measured at the antenna connector in dBm, 2) the received power of the mobile station on the forward link measured at the antenna connector in dBm, and 3) the closed-loop power control commands, received from the base station per time unit. From this Information, the load monitoring device the real-time traffic loading conditions the base station are derived. In the preferred embodiment, is the load monitoring device with the base station hardwired to avoid errors caused by the time-variation in the propagation effects on the air interface are introduced.

The above information while Peak or peak hours and during non-peak usage times measured. In the preferred embodiment causes the Load monitoring device every thirty Minutes a call for a two-minute Call duration. In the period in which the control of the device Traffic channel has, it continuously measures the transmission power the mobile station and processed to an average to obtain mobile station transmit power parameter. By comparing the average transmit power parameter measured in peak hours was with the value measured in the non-peak times, can the load monitoring device the loading effect on system performance derived. In other embodiments, measures the load monitoring device other performance-related parameters, such as the closed-loop power control commands, and processes them to an average value of a variable Parameter which transmit gain adjust is referred to obtain. The transmit gain adjust parameter are then also used to determine the loading effect on system performance derive.

The Load monitoring device will be real-time data also to the system resource management station further, where an appropriate measure may be taken based on the loading effect on system performance. For example, the load monitoring device be used to automatically a warning or an alarm send based on the processed parameters, or to the system inform resource management agency, if the system performance over a predetermined threshold deteriorated away. This warning can be used to produce corrective action in real time, such as denial of further access to the generating base station by other mobile stations, or simply by graphical representations of the loading effect on system performance over a Day cycle. further, the real-time data will be used to the base stations efficient allocate resources in a system.

BRIEF DESCRIPTION OF THE DRAWINGS

The Features, objects and advantages of the present invention will become more apparent from the box below detailed description when taken in conjunction with the drawings, in which like continuously identify numerals correspondingly throughout and in which:

<figref idrefs="S22">1</figref> a abstract overview of the system of the present invention;

<figref idrefs="S22">2</figref> a Presentation of selected sections the load monitoring device of the present invention; and

<figref idrefs="S23">3</figref> the The method of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

I. analysis

The present invention is based on the behavior of the base station under varying degrees of traffic load or Verkehrsausbelastung. Specifically, the more mobile stations transmit on the common CDMA traffic channel, the base station is less sensitive to each consignment by a mobile station, and therefore they need to so aggressive closed-loop power control carry out, to ensure that all &lt;?page 5?&gt;Mobile station broadcasts at the base station arrive with the same average power. Thus, when would a given mobile station were stationary and also not by time change the propagation effects affected (ie hard-wired to the Base station) would, the closed-loop power control commands it receives from the base station would receive only by the reverse link CDMA channel loading be controlled or driven, and not by variations the reverse link transmission power this mobile station, as received at the base station (Which would otherwise be constant). Thus, in the present invention, the load monitoring device the Workload effect on system performance from the difference between its own transmit power and the transmit gain adjust commands derived by the base station.

The sensitivity a base station in dBm over Reverse link transmissions by the mobile station is given by: <st32:df xmlns:st32="http://lighthouseip.com/">S = -134 + NF + E<st32:sub>B</st32:sub>/ N<st32:sub>0</st32:sub> + X<st32:sub>L</st32:sub> (1)</st32:df>in which NF (noise figure) is the noise figure of the base station in dB, E_B/ N₀ the ratio of Energy-per-bit to the Rückwärtsverbindungsinformationsbits to the noise spectral density in the CDMA bandwidth in dB, and X_L the system load in dB. In other words X_L equal to 10 [log (1 - X)], where X is the ratio of the Number of simultaneous mobile stations on the reverse link CDMA channel to the theoretical maximum number of mobile stations that the reverse link CDMA channel support can, is. sensitivity the base station is the threshold in dB, at which the base station in an appropriate manner, the reverse link transmission can receive from the mobile station. Thus, taking as you see can, sensitivity the base station from when the system load X_L elevated.

The Transmission power of a power-controlled mobile station is equal to the base station sensitivity less the reverse link path loss. Ie., That the mobile station at a power level needs to send, which is high enough the reverse link path loss overcome, and to still with a sufficient level at base station arrive. In mathematical terms:<st32:df xmlns:st32="http://lighthouseip.com/">P<st32:sub>t</st32:sub><st32:sup>s</st32:sup> = S + L<st32:sup>r</st32:sup><st32:sub>p</st32:sub> (2)</st32:df>where P_t^s the transmit power the mobile station is as in the antenna connection element it is measured in dBm, S is the sensitivity of the base station as defined in equation (1), and L^r_p the reverse link path loss is provided between the antenna connector of the mobile station and the receive antenna connector of the base station in dB. This Factor has the propagation loss, antenna gain and the feeder loss.

By Substitution of equation (1) and (2), the system load can be expressed as a function of the transmit power of the mobile station, namely as: <st32:df xmlns:st32="http://lighthouseip.com/">X<st32:sub>L</st32:sub> = 134 - NF - E<st32:sub>B</st32:sub>/ N<st32:sub>0</st32:sub> + P<st32:sub>t</st32:sub><st32:sup>s</st32:sup> - L<st32:sup>r</st32:sup><st32:sub>p</st32:sub> (3)</st32:df>

The Sizes NF, L^r_p and e_b/ N₀ are constants and hanging not to states of load from, thus equation (3) can be rewritten in <st32:df xmlns:st32="http://lighthouseip.com/">X<st32:sub>L</st32:sub> = C + P<st32:sub>t</st32:sub><st32:sup>s</st32:sup> (4)</st32:df>in which C is a constant and P_t^s the is transmission power of the mobile station, as measured at the antenna connector in dBm. Thus, (4) is obtained by substituting equation Equation (3): <st32:df xmlns:st32="http://lighthouseip.com/">C = 134 - NF - E<st32:sub>b</st32:sub>/ N<st32:sub>O</st32:sub> - L<st32:sup>r</st32:sup><st32:sub>p</st32:sub>, (5)</st32:df>

It Note that E_b/ N_O here is assumed to be constant, since in the preferred embodiment the load monitoring device is hard-wired to the base station, which is viewed, and therefore not prone is over temporal variation, changing by itself propagation effects caused.

There Equation (5) for any date applies, the loading effect difference between two expressed separate measurement periods are as: <st32:df xmlns:st32="http://lighthouseip.com/">X<st32:sub>L</st32:sub>(T2) - X<st32:sub>L</st32:sub>(T1) = P<st32:sup>s</st32:sup><st32:sub>t</st32:sub>(T2) - P<st32:sup>s</st32:sup><st32:sub>t</st32:sub>(T1) (6)</st32:df>where t₂ and t₁ any two different measurement times. Thus, the transmission power P_t^s the unit during a compared non-peak usage period with a peak usage period in order to determine the effect of loading on system performance.

otherwise considered can be used, the average transmit gain adjust to to determine the effect of loading on system performance. With Referring back to equation (3), there is also path loss on the forward link, the equal to the forward link power is received from the mobile station, minus the forward link power, that is sent by the base station. In mathematical terms:<st32:df xmlns:st32="http://lighthouseip.com/">L<st32:sup>f</st32:sup><st32:sub>p</st32:sub> = P<st32:sup>s</st32:sup><st32:sub>r</st32:sub> - P<st32:sup>b</st32:sup><st32:sub>t</st32:sub> (7)</st32:df>where L^f_p the forward link path loss between the transmitting antenna of the base station and the &lt;?page 6?&gt;Antenna connector of the mobile station in dB, P^s_r the Forward link received power the mobile station is measured at the antenna connector in dBm, and P^b_t the is transmission power of the base station as measured at the antenna connector in dBm. By applying the reciprocity theorem that the average Forward link path loss equal to the average reverse link path loss is, the system load can be disengaged be as a function of reverse link power, that is sent by the mobile station, the forward link power, which is received from the mobile station and the forward link power, that is sent by the base station, by substituting of the equations (3) and (7): <st32:df xmlns:st32="http://lighthouseip.com/">X<st32:sub>L</st32:sub> = 134 - NF - E<st32:sub>b</st32:sub>/ N<st32:sub>0</st32:sub> + P<st32:sup>s</st32:sup><st32:sub>t</st32:sub> + P<st32:sup>s</st32:sup><st32:sub>r</st32:sub> - P<st32:sup>b</st32:sup><st32:sub>t</st32:sub> (8th)</st32:df>

There but the mobile station closed-loop transmit gain adjust commands used to calculate its transmit power, Equation (8) preferably expressed are as: <st32:df xmlns:st32="http://lighthouseip.com/">P<st32:sup>s</st32:sup><st32:sub>t</st32:sub> + P<st32:sup>s</st32:sup><st32:sub>r</st32:sub> - T<st32:sub>adj</st32:sub> = K (9)</st32:df>in which T_adj the transmit gain adjust the mobile unit response in dB on the closed-loop power control commands is sent from the base station, and k is a factor of turnaround is that the mobile station uses, to the open-loop transmit power to calculate. It should be noted that even though reciprocity of the forward and Reverse link path loss was adopted in equation (7), any errors in this assumption be compensated for by the closed-loop power control commands, are thus reflected in T_adj,

By Substitution of equation (8) and (9), the base station load in terms of the transmit gain adjust, T_adjbe expressed as follows: <st32:df xmlns:st32="http://lighthouseip.com/">X<st32:sub>L</st32:sub> = 134 - NF - E<st32:sub>b</st32:sub>/ N<st32:sub>0</st32:sub> + K + T<st32:sub>adj</st32:sub> - P<st32:sup>b</st32:sup><st32:sub>t</st32:sub> (10)</st32:df>what easier can be rewritten as: <st32:df xmlns:st32="http://lighthouseip.com/">X<st32:sub>L</st32:sub> = C + T<st32:sub>adj</st32:sub> (11)</st32:df>where C is a constant which is given by: <st32:df xmlns:st32="http://lighthouseip.com/">C = 134 - NF - E<st32:sub>b</st32:sub>/ N<st32:sub>0</st32:sub> + K - P<st32:sub>t</st32:sub><st32:sup>b</st32:sup> (12)</st32:df>

There Equation (12) for all time points is considered, the loading effect difference between two expressed separate measurement periods are as: <st32:df xmlns:st32="http://lighthouseip.com/">X<st32:sub>L</st32:sub>(t<st32:sub>2</st32:sub>) - X<st32:sub>L</st32:sub>(t<st32:sub>1</st32:sub>) = T<st32:sub>adj</st32:sub>(t<st32:sub>2</st32:sub>) - T<st32:sub>adj</st32:sub>(t<st32:sub>1</st32:sub>) (13)</st32:df>where t₂ and t₁ any two different measurement times are. Thus, the T_adj during a non-peak usage period be compared with that of a peak usage period to determine the effect of Load to determine the system performance. There are obvious , Many performance-related parameters that can be measured to the system load at a time to the system load to another compare time. For example, the above analysis accomplished in order to obtain a relationship of the load, expressed as Function of the received power at the mobile station.

II. Load monitoring system and method

The Relationship, the above equation (6) or (13) is determined, utilized in the present invention to provide real-time monitoring provide and management of the system load. <figref idrefs="S22">1</figref> provides an abstract overview the system <figref>100</figref> of the present invention. A CDMA base station <figref>112</figref> is To see the exemplary in wireless communication with four mobile stations <figref>108a</figref>-<figref>108d</figref> by an antenna <figref>110</figref> is. The mobile stations<figref>108a</figref>-<figref>108d</figref> are For example, power controlled CDMA cellular radio telephones of the prior Technology. The base station<figref>112</figref> is also in periodic Communication with a load monitoring device <figref>102</figref>. which is a conventional power-driven CDMA cellular radiotelephone <figref>104</figref> may have that a data recording retaining and processing <figref>106</figref> coupled, such as a CDMA diagnostic monitoring device or other data processing apparatus of the prior art.

alternative , the load monitoring device <figref>102</figref> a be specially modified mobile station, the microprocessor a contains, which is programmed to control the data recording and processing functions perform.

In the preferred embodiment, is the load monitoring device <figref>102</figref> hardwired base station <figref>112</figref> about Electric wire <figref>116</figref>To any time variation of both the Propagation effects and E_b/ N₀ on the data obtained by the load monitoring device <figref>102</figref> recorded be to minimize. In alternate embodiments, the load monitoring device<figref>102</figref> however stationary his while it wireless communications with the base station <figref>112</figref> begins the relevant data record described below.

The base station <figref>112</figref> is also in communication with a System management center <figref>114</figref>In which all PCs and Network computers are needed to fault monitoring, Diagnosis and management of the base station <figref>112</figref> by&lt;?page 7?&gt;out. In<figref idrefs="S22">1</figref> passes the base station <figref>112</figref> System operating parameters and warnings to the system management center <figref>114</figref> cable <figref>118</figref> continue. In alternative embodiments, However, the base station <figref>112</figref> with the system management center <figref>114</figref> among Using any backhaul communication method, which is known in the art, to communicate, such as using wireless point-to-point microwave communication.

in the normal operation of the system <figref>100</figref> communicate the mobile stations <figref>108a</figref>-<figref>108d</figref> periodically the base station <figref>112</figref>Either to make a call, a Call to receive (or to stop), or by various overhead messages to or from the base station <figref>112</figref> to send or receive. During peak periods of usage, such as in the middle of the day, it can be expected that all four mobile stations <figref>108a</figref>-<figref>108d</figref> in simultaneous Communication with the base station <figref>112</figref> are thereby the system load and interference on the reverse link is increased. Conversely, one can expect that, during non-peak usage times such as in the middle of the night, only one of the mobile stations <figref>108a</figref>-<figref>108d</figref> to any given time in simultaneous communication with base station <figref>112</figref> is to give the system load is reduced. It is noted that fewer or more than four mobile stations in simultaneous communication with the base station <figref>112</figref> may be located, depending on the capacity of the base station <figref>112</figref>, For simplicity, is <figref idrefs="S22">1</figref> However, only four mobile stations <figref>108a</figref>-<figref>108d</figref> shown.

Additionally causes the load monitoring device <figref>102</figref> periodically a call of a predetermined length at the base station <figref>112</figref> according to a predetermined Schedule. In the preferred embodiment begins the Load monitoring device <figref>102</figref> a Call two minutes Duration at the base station <figref>112</figref> every thirty minutes while both peak and non-peak periods. It is clear that this predetermined timing chart in both the Duration (shorter or longer than two minutes) and in the frequency (shorter or longer than thirty minutes) can be varied depending of the monitoring and management needs the system management center <figref>114</figref>, In the preferred embodiment, was a two-minute selected call time because they close to the average call duration of an actual Cell cellular phone is. In addition, the frequency of each thirty minutes chosen be as a trade-off or compromise between data resolution and Data quantity.

If any mobile stations <figref>108a</figref>-<figref>108d</figref> with base station <figref>112</figref> communicate, the base station transmits <figref>112</figref> Closed-loop power control commands to the active mobile stations <figref>108a</figref>-<figref>108d</figref>, as described in the aforementioned <patcit><text>US Pat. No. 5,056,109</text></patcit>, Each of the closed-loop power control commands of different at the active mobile stations <figref>108a</figref>-<figref>108d</figref> was sent, instructs the particular mobile station, its transmit power either to increase or to reduce by an amount in the order of 1 dB, so that the transmitted signal of each mobile station as at the base station <figref>112</figref> arrive is that the signal-to-noise ratio or E_b/ N_O sufficient to provide a minimum required voice quality ensure. Also sends, whenever load monitoring device<figref>102</figref> With the base station <figref>112</figref> communicating, the base station <figref>112</figref> similarly Closed-loop power control commands to load monitoring device <figref>102</figref>. because they base station <figref>112</figref> as just another Mobile station appears.

Now Referring to <figref idrefs="S22">2</figref> is an illustration of selected parts the load monitoring device <figref>102</figref> shown. Radio frequency signals or RF signals (RF = radio frequency), the both modulated information as well as closed-loop power control commands have to be of the load monitoring device <figref>102</figref> on antenna <figref>200</figref> receive. It is again noted that in preferred embodiment, Signals for load monitoring device <figref>102</figref> from base station <figref>112</figref> (please refer <figref idrefs="S22">1</figref>) Cable <figref>116</figref> Posted be sent directly to an antenna port of load monitoring device <figref>102</figref> coupled are. In alternative embodiments, However, the load monitoring device used <figref>102</figref> a Standard antenna <figref>200</figref>, Which is known in the art.

The received signals from a duplexer <figref>202</figref> at one Low-noise amplifier or LNA (LNA low-noise amplifier) <figref>204</figref> routed or forwarded, wherein the front-end gain adjusted becomes. Then, in the automatic gain control amplifier or AGC amplifier (AGC = Automatic gain control) <figref>206</figref> the intermediate frequency power level or IF power level (IF = intermediate frequency) adjusted. The received signal strength is the indicator of the measured signal strength or RSSI (RSSI = received signal strength indicator) <figref>212</figref> measured, the received the signal strength used an open loop power control signal <figref>214</figref> to to generate. In addition, the received signal in an analog-to-digital converter is (A / D) <figref>208</figref> sampled or sampled and then demodulated digital in a demodulator (DEMOD) <figref>210</figref>, The closed-loop power control commands<figref>216</figref> will then to a combiner <figref>228</figref> provided, where they combined are using the open-loop power control signal <figref>214</figref> and be used to control the transmit power of the Leis&lt;?page 8?&gt;processing amplifier or PA (PA = Power Amplifier) <figref>220</figref> adapt.

In the preferred embodiment is characterized the data processor <figref>218</figref> the output power of the PA <figref>220</figref> on, namely scaled so that it represents the output power, as it at the connector or connecting element of the antenna <figref>200</figref> measured becomes. accumulated in the preferred embodiment the data processor <figref>218</figref> the output power measurements over a Datenleitunginie <figref>232</figref> about the two minute Call duration and averages them to the average transmission power the mobile station to receive.

In are an alternative embodiment, the closed-loop power control commands <figref>216</figref> from base station <figref>112</figref> extracted from the demodulated signal and data processor <figref>218</figref> recorded. In this alternative embodiment accumulates the data processor <figref>218</figref> the closed-loop power control commands over the two-minute call duration and it averages to T_ADJ to obtain. There the CDMA frame has a duration of 20 ms, and the base station can send a closed loop power control command per frame, T would_ADJ 6000 individual power adjustment values based. Statistics higher Procedure can are also generated.

Of the data processor <figref>218</figref> may be an integral part of a modified may be mobile station, or a separate recording and its processing device, such as a CDMA diagnostic device, which is known in the art. The data processor<figref>218</figref> compares the average transmit power (or alternatively, the average T_ADJValue) of a non-peak usage period was generated with the average transmit power (or alternatively the average T_ADJValue) of a peak usage period was generated to determine the difference in system loading as derived in Equations (6) or (13). Based on this Information, the data processor <figref>218</figref> A warning or an alarm signal or other information signal <figref>230</figref> for a suitable measure to the system management center <figref>114</figref> (please refer <figref idrefs="S22">1</figref>) send. The warning or other information signal<figref>230</figref> can be used to produce reports on the state of the system load, or to such a real-time measure take that further access is denied to the system, when the load exceeds a certain threshold.

<figref idrefs="S23">3</figref> provides the method illustrates the present invention. The method begins in block <figref>302</figref>In which the load monitoring device a Call to the base station during an auxiliary time T1 causes. For the duration of the call, which in the preferred embodiment two minutes is, measures the load monitoring device a power related parameter, which in the preferred embodiment Either the transmitting power of the mobile station may be, or T_ADJ(T1) in an alternate embodiment, in block <figref>304</figref>, The load monitoring device then initiates a call to the base station during the Peak time T2 in block <figref>306</figref> and measures the same power related parameters for the duration of the call in block <figref>308</figref>, In block<figref>310</figref> calculated the load monitoring device then X_L(T2) - X_L(T1) as defined in either Equation (6) or (13), and compares this in with a predetermined threshold of Y dB Block <figref>312</figref>, The Threshold Y can be customized for each base station are determined based on the desired base station performance.

If in block <figref>310</figref> calculated difference X_L(T2) - X_L(T1) is greater than the predetermined threshold Y, then the load monitoring device sends a warning to the system management center in block <figref>314</figref>. and appropriate measures be taken, such as refusing further access to the system. In this case, would the load monitoring device then begin again the process in block <figref>302</figref> to begin. If the block<figref>310</figref> calculated difference X_L(T2) - X_L(T1) is less than the predetermined threshold Y, then the load monitoring device sends no warning, and only starts again the process in block <figref>302</figref>,

In other embodiments Modifications on the river <figref idrefs="S22">2</figref> made to the procedure for accommodate different applications. For example, the load monitoring device several calls in blocks <figref>302</figref> and <figref>306</figref> cause all thirty Minutes are spaced, during the peak and non-peak hours, to obtain the average values. In addition, the load monitoring device can be configured be to send information to the system management center, regardless of if the load has exceeded a predetermined threshold. This information could For example, useful be to a graph of the time versus load for a daily to generate operating cycle. Furthermore, many Adjustments to both the timing chart as well as the use the information may be made without the use of the inventive Activity.

The present invention is not shown herein embodiments be limited and the foregoing description of the preferred Ausfüh The exemplary embodiments is therefore intended only by way of examples, to the skilled person to allow make the present invention or use. The different Mo&lt;?page 9?&gt;difikationen to these embodiments the skilled person will be readily apparent, and the general Principles defined herein may in other embodiments be applied without the use of inventive step.